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Li B, Deng M, Pan Y, Chen W, He T, Chen L, Zheng Y, Rong J. Response of the root morphological structure of Fokienia hodginsii seedlings to competition from neighboring plants in a heterogeneous nutrient environment. FRONTIERS IN PLANT SCIENCE 2024; 14:1327322. [PMID: 38298603 PMCID: PMC10829109 DOI: 10.3389/fpls.2023.1327322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/29/2023] [Indexed: 02/02/2024]
Abstract
Introduction Critical changes often occur in Fokienia hodginsii seedlings during the process of growth owing to differences in the surrounding environment. The most common differences are heterogeneous nutrient environments and competition from neighboring plants. Methods In this study, we selected one-year-old, high-quality Fokienia hodginsii seedlings as experimental materials. Three planting patterns were established to simulate different competitive treatments, and seedlings were also exposed to three heterogeneous nutrient environments and a homogeneous nutrient environment (control) to determine their effect on the root morphology and structure of F. hodginsii seedlings. Results Heterogeneous nutrient environments, compared with a homogeneous environment, significantly increased the dry matter accumulation and root morphology indexes of the root system of F. hodginsii, which proliferated in nutrient-rich patches, and the P heterogeneous environment had the most significant enhancement effect, with dry matter accumulation 70.2%, 7.0%, and 27.0% higher than that in homogeneous and N and K heterogeneous environments, respectively. Homogeneous environments significantly increased the specific root length and root area of the root system; the dry matter mass and morphological structure of the root system of F. hodginsii with a heterospecific neighbor were higher than those under conspecific neighbor and single-plant treatments, and the root area of the root system under the conspecific neighbor treatment was higher than that under the heterospecific neighbor treatment, by 20% and 23%, respectively. Moreover, the root system under heterospecific neighbor treatment had high sensitivity; the heterogeneous nutrient environment increased the mean diameter of the fine roots of the seedlings of F. hodginsii and the diameter of the vascular bundle, and the effect was most significant in the P heterogeneous environment, exceeding that in the N and K heterogeneous environments. The effect was most significant in the P heterogeneous environment, which increased fine root diameter by 20.5% and 10.3%, respectively, compared with the homogeneous environment; in contrast, the fine root vascular ratio was highest in the homogeneous environment, and most of the indicators of the fine root anatomical structure in the nutrient-rich patches were of greater values than those in the nutrient-poor patches in the different heterogeneous environments; competition promoted most of the indicators of the fine root anatomical structure of F. hodginsii seedlings. According a principal component analysis (PCA), the N, Pm and K heterogeneous environments with heterospecific neighbors and the P heterogeneous environment with a conspecific neighbor had higher evaluation in the calculation of eigenvalues of the PCA. Discussion The root dry matter accumulation, root morphology, and anatomical structure of F. hodginsii seedlings in the heterogeneous nutrient environment were more developed than those in the homogeneous nutrient environment. The effect of the P heterogeneous environment was the most significant. The heterospecific neighbor treatment was more conducive to the expansion and development of root morphology of F. hodginsii seedlings than were the conspecific neighbor and single-plant treatments.
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Affiliation(s)
- Bingjun Li
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mi Deng
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yanmei Pan
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wenchen Chen
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Tianyou He
- College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Liguang Chen
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yushan Zheng
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jundong Rong
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
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2
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Guan ZH, Cao Z, Li XG, Scholten T, Kühn P, Wang L, Yu RP, He JS. Soil phosphorus availability mediates the effects of nitrogen addition on community- and species-level phosphorus-acquisition strategies in alpine grasslands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167630. [PMID: 37806588 DOI: 10.1016/j.scitotenv.2023.167630] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Plants modulate their phosphorus (P) acquisition strategies (i.e., change in root morphology, exudate composition, and mycorrhizal symbiosis) to adapt to varying soil P availability. However, how community- and species-level P-acquisition strategies change in response to nitrogen (N) supply under different P levels remains unclear. To address this research gap, we conducted an 8-year fully factorial field experiment in an alpine grassland on the Qinghai-Tibet Plateau (QTP) combined with a 12-week glasshouse experiment with four treatments (N addition, P addition, combined N and P addition, and control). In the field experiment (community-level), when P availability was low, N addition increased the release of carboxylate from roots and led to a higher percentage of colonisation by arbuscular mycorrhizal fungi (AMF), along with decreased root length, specific root length (SRL), and total root length colonised by AMF. When P availability was higher, N addition resulted in an increase in the plant's demand for P, accompanied by an increase in root diameter and phosphatase activity. In the glasshouse experiment (species-level), the P-acquisition strategies of grasses and sedge in response to N addition alone mirrored those observed in the field, exhibiting a reduction in root length, SRL, and total root length colonised, but an increased percentage of AMF colonisation. Forbs responded to N addition alone with increased investment in all P-acquisition strategies, especially increased root biomass and length. P-acquisition strategies showed consistent changes among all species in response to combined N and P addition. Our results suggest that increased carboxylate release and AMF colonisation rate are common P-acquisition strategies of plants in alpine grasslands under N-induced P limitation. The main difference in P-acquisition strategies between forbs and grasses/sedges in response to N addition under low-P conditions was an increase in root biomass and length.
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Affiliation(s)
- Zhen-Huan Guan
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Zuonan Cao
- Department of Geosciences, Soil Science and Geomorphology, University of Tübingen, Tübingen 72070, Germany
| | - Xiao Gang Li
- College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Thomas Scholten
- Department of Geosciences, Soil Science and Geomorphology, University of Tübingen, Tübingen 72070, Germany
| | - Peter Kühn
- Department of Geosciences, Soil Science and Geomorphology, University of Tübingen, Tübingen 72070, Germany
| | - Lin Wang
- College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Rui-Peng Yu
- Beijing Key Laboratory of Biodiversity and Organic Farming, Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Jin-Sheng He
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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3
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Bornø ML, Zervas A, Bak F, Merl T, Koren K, Nicolaisen MH, Jensen LS, Müller-Stöver DS. Differential impacts of sewage sludge and biochar on phosphorus-related processes: An imaging study of the rhizosphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:166888. [PMID: 37730064 DOI: 10.1016/j.scitotenv.2023.166888] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/15/2023] [Accepted: 09/05/2023] [Indexed: 09/22/2023]
Abstract
Recycling of phosphorus (P) from waste streams in agriculture is essential to reduce the negative environmental effects of surplus P and the unsustainable mining of geological P resources. Sewage sludge (SS) is an important P source; however, several issues are associated with the handling and application of SS in agriculture. Thus, post-treatments such as pyrolysis of SS into biochar (BC) could address some of these issues. Here we elucidate how patches of SS in soil interact with the living roots of wheat and affect important P-related rhizosphere processes compared to their BC counterparts. Wheat plants were grown in rhizoboxes with sandy loam soil, and 1 cm Ø patches with either SS or BC placed 10 cm below the seed. A negative control (CK) was included. Planar optode pH sensors were used to visualize spatiotemporal pH changes during 40 days of plant growth, diffusive gradients in thin films (DGT) were applied to map labile P, and zymography was used to visualize the spatial distribution of acid (ACP) and alkaline (ALP) phosphatase activity. In addition, bulk soil measurements of available P, pH, and ACP activity were conducted. Finally, the relative abundance of bacterial P-cycling genes (phoD, phoX, phnK) was determined in the patch area rhizosphere. Labile P was only observed in the area of the SS patches, and SS further triggered root proliferation and increased the activity of ACP and ALP in interaction with the roots. In contrast, BC seemed to be inert, had no visible effect on root growth, and even reduced ACP and ALP activity in the patch area. Furthermore, there was a lower relative abundance of phoD and phnK genes in the BC rhizosphere compared to the CK. Hence, optimization of BC properties is needed to increase the short-term efficiency of BC from SS as a P fertilizer.
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Affiliation(s)
- Marie Louise Bornø
- University of Copenhagen, Department of Plant & Environmental Sciences, Thorvaldsensvej 40, 1821 Frederiksberg, Denmark.
| | - Athanasios Zervas
- Aarhus University, Department of Environmental Science, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Frederik Bak
- University of Copenhagen, Department of Plant & Environmental Sciences, Thorvaldsensvej 40, 1821 Frederiksberg, Denmark; Austrian Institute of Technology, Bioresources Unit, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Theresa Merl
- Aarhus University Centre for Water Technology, Department of Biology - Microbiology, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Klaus Koren
- Aarhus University Centre for Water Technology, Department of Biology - Microbiology, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Mette H Nicolaisen
- University of Copenhagen, Department of Plant & Environmental Sciences, Thorvaldsensvej 40, 1821 Frederiksberg, Denmark
| | - Lars S Jensen
- University of Copenhagen, Department of Plant & Environmental Sciences, Thorvaldsensvej 40, 1821 Frederiksberg, Denmark
| | - Dorette S Müller-Stöver
- University of Copenhagen, Department of Plant & Environmental Sciences, Thorvaldsensvej 40, 1821 Frederiksberg, Denmark
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Cornejo NS, Becker JN, Hemp A, Hertel D. Effects of land-use change and disturbance on the fine root biomass, dynamics, morphology, and related C and N fluxes to the soil of forest ecosystems at different elevations at Mt. Kilimanjaro (Tanzania). Oecologia 2023; 201:1089-1107. [PMID: 36944897 PMCID: PMC10113319 DOI: 10.1007/s00442-023-05353-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 03/02/2023] [Indexed: 03/23/2023]
Abstract
Tropical forests are threatened by anthropogenic activities such as conversion into agricultural land, logging and fires. Land-use change and disturbance affect ecosystems not only aboveground, but also belowground including the ecosystems' carbon and nitrogen cycle. We studied the impact of different types of land-use change (intensive and traditional agroforestry, logging) and disturbance by fire on fine root biomass, dynamics, morphology, and related C and N fluxes to the soil via fine root litter across different ecosystems at different elevational zones at Mt. Kilimanjaro (Tanzania). We found a decrease in fine root biomass (80-90%), production (50%), and C and N fluxes to the soil via fine root litter (60-80%) at all elevation zones. The traditional agroforestry 'Chagga homegardens' (lower montane zone) showed enhanced fine root turnover rates, higher values of acquisitive root morphological traits, but similar stand fine root production, C and N fluxes compared to the natural forest. The decrease of C and N fluxes with forest disturbance was particularly strong at the upper montane zone (60 and 80% decrease, respectively), where several patches of Podocarpus forest had been disturbed by fire in the previous years. We conclude that changes on species composition, stand structure and land management practices resulting from land-use change and disturbance have a strong impact on the fine root system, modifying fine root biomass, production and the C and N supply to the soil from fine root litter, which strongly affects the ecosystems' C and N cycle in those East African tropical forest ecosystems.
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Affiliation(s)
- Natalia Sierra Cornejo
- Plant Ecology and Ecosystems Research, Albrecht-Von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
- Department of Botany, Ecology and Plant Physiology, University of La Laguna, La Laguna, Spain
| | - Joscha N Becker
- Institute of Soil Science, CEN Center for Earth System Research and Sustainability, University of Hamburg, Hamburg, Germany
| | - Andreas Hemp
- Department of Plant Physiology, Bayreuth University, Bayreuth, Germany
| | - Dietrich Hertel
- Plant Ecology and Ecosystems Research, Albrecht-Von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany.
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Schäfer ED, Owen MR, Band LR, Farcot E, Bennett MJ, Lynch JP. Modeling root loss reveals impacts on nutrient uptake and crop development. PLANT PHYSIOLOGY 2022; 190:2260-2278. [PMID: 36047839 PMCID: PMC9706447 DOI: 10.1093/plphys/kiac405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/26/2022] [Indexed: 05/25/2023]
Abstract
Despite the widespread prevalence of root loss in plants, its effects on crop productivity are not fully understood. While root loss reduces the capacity of plants to take up water and nutrients from the soil, it may provide benefits by decreasing the resources required to maintain the root system. Here, we simulated a range of root phenotypes in different soils and root loss scenarios for barley (Hordeum vulgare), common bean (Phaseolus vulgaris), and maize (Zea mays) using and extending the open-source, functional-structural root/soil simulation model OpenSimRoot. The model enabled us to quantify the impact of root loss on shoot dry weight in these scenarios and identify in which scenarios root loss is beneficial, detrimental, or has no effect. The simulations showed that root loss is detrimental for phosphorus uptake in all tested scenarios, whereas nitrogen uptake was relatively insensitive to root loss unless main root axes were lost. Loss of axial roots reduced shoot dry weight for all phenotypes in all species and soils, whereas lateral root loss had a smaller impact. In barley and maize plants with high lateral branching density that were not phosphorus-stressed, loss of lateral roots increased shoot dry weight. The fact that shoot dry weight increased due to root loss in these scenarios indicates that plants overproduce roots for some environments, such as those found in high-input agriculture. We conclude that a better understanding of the effects of root loss on plant development is an essential part of optimizing root system phenotypes for maximizing yield.
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Affiliation(s)
- Ernst D Schäfer
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Markus R Owen
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Leah R Band
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
- School of Biosciences, University of Nottingham, Nr Loughborough, LE12 5RD, UK
| | - Etienne Farcot
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Malcolm J Bennett
- School of Biosciences, University of Nottingham, Nr Loughborough, LE12 5RD, UK
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6
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Kotowska MM, Samhita S, Hertel D, Triadiati T, Beyer F, Allen K, Link RM, Leuschner C. Consequences of tropical rainforest conversion to tree plantations on fine root dynamics and functional traits. OIKOS 2022. [DOI: 10.1111/oik.08898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Martyna M. Kotowska
- Dept of Plant Ecology and Ecosystems Research, Albrecht‐von‐Haller Inst. for Plant Sciences, Univ. of Goettingen Göttingen Germany
| | - Sasya Samhita
- Dept of Plant Ecology and Ecosystems Research, Albrecht‐von‐Haller Inst. for Plant Sciences, Univ. of Goettingen Göttingen Germany
| | - Dietrich Hertel
- Dept of Plant Ecology and Ecosystems Research, Albrecht‐von‐Haller Inst. for Plant Sciences, Univ. of Goettingen Göttingen Germany
| | - Triadiati Triadiati
- Dept of Biology, Faculty of Mathematics and Natural Sciences, IPB Univ. Bogor Indonesia
| | - Friderike Beyer
- Chair of Silviculture, Faculty of Environment and Natural Resources, Univ. of Freiburg Freiburg Germany
| | - Kara Allen
- Manaaki Whenua‐Landcare Research Lincoln New Zealand
| | - Roman M. Link
- Chair of Ecophysiology and Vegetation Ecology, Julius von Sachs Inst. of Biological Sciences, Univ. of Würzburg Würzburg Germany
| | - Christoph Leuschner
- Dept of Plant Ecology and Ecosystems Research, Albrecht‐von‐Haller Inst. for Plant Sciences, Univ. of Goettingen Göttingen Germany
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7
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Mašková T, Maternová J, Těšitel J. Shoot: root ratio of seedlings is associated with species niche on soil moisture gradient. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:286-291. [PMID: 34850527 DOI: 10.1111/plb.13352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Surviving the seedling phase is crucial for the establishment of plant individuals and populations. In ecosystems with dynamic water availability such as temperate grasslands, seedlings should adjust their growth strategy not only to match the current conditions but also to secure resource acquisition in the future. Here, we explored evolutionary adaptations determining plant early growth strategies in herbaceous species of temperate grasslands differing in their requirements for soil water availability. We chose 15 plant genera, within which we selected species differing in their Ellenberg indicator values for moisture. We cultivated the seedlings under standard conditions with sufficient water supply for 4 weeks. Subsequently, we measured length-based and mass-based shoot:root ratio to investigate seedling growth strategy and its association with species ecological niche. Seed size and content of soil-borne nutrients were considered as potential covariates affecting this association. Linear mixed-effect models identified the length-based shoot:root ratio of seedlings was positively associated with soil moisture requirements in a congeneric species comparison. Nitrogen and phosphorus seed concentrations had an additional negative effect on the shoot:root ratio. Neither of these trends was found for the mass-based shoot:root ratio. We demonstrated for the first time that there might be a general adaptation modifying the seedling shoot:root ratio according to the species niche position on the soil moisture gradient in temperate grassland species across a broad range of angiosperm phylogeny. This adaptation seems to be affected by seed mineral nutrient reserves and may operate in parallel to the well-known phenotypic plasticity.
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Affiliation(s)
- T Mašková
- Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czech Republic
- Ecology and Conservation Biology, Institute of Plant Sciences, University of Regensburg, Regensburg, Germany
| | - J Maternová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - J Těšitel
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
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8
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Wang C, Brunner I, Wang J, Guo W, Geng Z, Yang X, Chen Z, Han S, Li MH. The Right-Skewed Distribution of Fine-Root Size in Three Temperate Forests in Northeastern China. FRONTIERS IN PLANT SCIENCE 2022; 12:772463. [PMID: 35069627 PMCID: PMC8777189 DOI: 10.3389/fpls.2021.772463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Trees can build fine-root systems with high variation in root size (e.g., fine-root diameter) and root number (e.g., branching pattern) to optimize belowground resource acquisition in forest ecosystems. Compared with leaves, which are visible above ground, information about the distribution and inequality of fine-root size and about key associations between fine-root size and number is still limited. We collected 27,573 first-order fine-roots growing out of 3,848 second-order fine-roots, covering 51 tree species in three temperate forests (Changbai Mountain, CBS; Xianrendong, XRD; and Maoershan, MES) in Northeastern China. We investigated the distribution and inequality of fine-root length, diameter and area (fine-root size), and their trade-off with fine-root branching intensity and ratio (fine-root number). Our results showed a strong right-skewed distribution in first-order fine-root size across various tree species. Unimodal frequency distributions were observed in all three of the sampled forests for first-order fine-root length and area and in CBS and XRD for first-order fine-root diameter, whereas a marked bimodal frequency distribution of first-order fine-root diameter appeared in MES. Moreover, XRD had the highest and MES had the lowest inequality values (Gini coefficients) in first-order fine-root diameter. First-order fine-root size showed a consistently linear decline with increasing root number. Our findings suggest a common right-skewed distribution with unimodality or bimodality of fine-root size and a generalized trade-off between fine-root size and number across the temperate tree species. Our results will greatly improve our thorough understanding of the belowground resource acquisition strategies of temperate trees and forests.
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Affiliation(s)
- Cunguo Wang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Ivano Brunner
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Junni Wang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Wei Guo
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Zhenzhen Geng
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Xiuyun Yang
- College of Forestry, Shanxi Agricultural University, Taigu, China
| | - Zhijie Chen
- International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, China
| | - Shijie Han
- International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, China
| | - Mai-He Li
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
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9
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Freschet GT, Pagès L, Iversen CM, Comas LH, Rewald B, Roumet C, Klimešová J, Zadworny M, Poorter H, Postma JA, Adams TS, Bagniewska‐Zadworna A, Bengough AG, Blancaflor EB, Brunner I, Cornelissen JHC, Garnier E, Gessler A, Hobbie SE, Meier IC, Mommer L, Picon‐Cochard C, Rose L, Ryser P, Scherer‐Lorenzen M, Soudzilovskaia NA, Stokes A, Sun T, Valverde‐Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Batterman SA, Gomes de Moraes M, Janeček Š, Lambers H, Salmon V, Tharayil N, McCormack ML. A starting guide to root ecology: strengthening ecological concepts and standardising root classification, sampling, processing and trait measurements. THE NEW PHYTOLOGIST 2021; 232:973-1122. [PMID: 34608637 PMCID: PMC8518129 DOI: 10.1111/nph.17572] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/22/2021] [Indexed: 05/17/2023]
Abstract
In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting-edge, meaningful and integrated knowledge. Consideration of the below-ground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, will improve trait comparisons across studies and integration of information across databases by providing standardised methods and controlled vocabularies. It is meant to be used not only as starting point by students and scientists who desire working on below-ground ecosystems, but also by experts for consolidating and broadening their views on multiple aspects of root ecology. Beyond the classical compilation of measurement protocols, we have synthesised recommendations from the literature to provide key background knowledge useful for: (1) defining below-ground plant entities and giving keys for their meaningful dissection, classification and naming beyond the classical fine-root vs coarse-root approach; (2) considering the specificity of root research to produce sound laboratory and field data; (3) describing typical, but overlooked steps for studying roots (e.g. root handling, cleaning and storage); and (4) gathering metadata necessary for the interpretation of results and their reuse. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers not to solely extract protocol recommendations for trait measurements from this work, but to take a moment to read and reflect on the extensive information contained in this broader guide to root ecology, including sections I-VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers' views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.
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Affiliation(s)
- Grégoire T. Freschet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
| | - Loïc Pagès
- UR 1115 PSHCentre PACA, site AgroparcINRAE84914Avignon cedex 9France
| | - Colleen M. Iversen
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Louise H. Comas
- USDA‐ARS Water Management Research Unit2150 Centre Avenue, Bldg D, Suite 320Fort CollinsCO80526USA
| | - Boris Rewald
- Department of Forest and Soil SciencesUniversity of Natural Resources and Life SciencesVienna1190Austria
| | - Catherine Roumet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Jitka Klimešová
- Department of Functional EcologyInstitute of Botany CASDukelska 13537901TrebonCzech Republic
| | - Marcin Zadworny
- Institute of DendrologyPolish Academy of SciencesParkowa 562‐035KórnikPoland
| | - Hendrik Poorter
- Plant Sciences (IBG‐2)Forschungszentrum Jülich GmbHD‐52425JülichGermany
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
| | | | - Thomas S. Adams
- Department of Plant SciencesThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Agnieszka Bagniewska‐Zadworna
- Department of General BotanyInstitute of Experimental BiologyFaculty of BiologyAdam Mickiewicz UniversityUniwersytetu Poznańskiego 661-614PoznańPoland
| | - A. Glyn Bengough
- The James Hutton InstituteInvergowrie, Dundee,DD2 5DAUK
- School of Science and EngineeringUniversity of DundeeDundee,DD1 4HNUK
| | | | - Ivano Brunner
- Forest Soils and BiogeochemistrySwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
| | - Johannes H. C. Cornelissen
- Department of Ecological ScienceFaculty of ScienceVrije Universiteit AmsterdamDe Boelelaan 1085Amsterdam1081 HVthe Netherlands
| | - Eric Garnier
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Arthur Gessler
- Forest DynamicsSwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
- Institute of Terrestrial EcosystemsETH Zurich8092ZurichSwitzerland
| | - Sarah E. Hobbie
- Department of Ecology, Evolution and BehaviorUniversity of MinnesotaSt PaulMN55108USA
| | - Ina C. Meier
- Functional Forest EcologyUniversity of HamburgHaidkrugsweg 122885BarsbütelGermany
| | - Liesje Mommer
- Plant Ecology and Nature Conservation GroupDepartment of Environmental SciencesWageningen University and ResearchPO Box 476700 AAWageningenthe Netherlands
| | | | - Laura Rose
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
- Senckenberg Biodiversity and Climate Research Centre (BiK-F)Senckenberganlage 2560325Frankfurt am MainGermany
| | - Peter Ryser
- Laurentian University935 Ramsey Lake RoadSudburyONP3E 2C6Canada
| | | | - Nadejda A. Soudzilovskaia
- Environmental Biology DepartmentInstitute of Environmental SciencesCMLLeiden UniversityLeiden2300 RAthe Netherlands
| | - Alexia Stokes
- INRAEAMAPCIRAD, IRDCNRSUniversity of MontpellierMontpellier34000France
| | - Tao Sun
- Institute of Applied EcologyChinese Academy of SciencesShenyang110016China
| | - Oscar J. Valverde‐Barrantes
- International Center for Tropical BotanyDepartment of Biological SciencesFlorida International UniversityMiamiFL33199USA
| | - Monique Weemstra
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Alexandra Weigelt
- Systematic Botany and Functional BiodiversityInstitute of BiologyLeipzig UniversityJohannisallee 21-23Leipzig04103Germany
| | - Nina Wurzburger
- Odum School of EcologyUniversity of Georgia140 E. Green StreetAthensGA30602USA
| | - Larry M. York
- Biosciences Division and Center for Bioenergy InnovationOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Sarah A. Batterman
- School of Geography and Priestley International Centre for ClimateUniversity of LeedsLeedsLS2 9JTUK
- Cary Institute of Ecosystem StudiesMillbrookNY12545USA
| | - Moemy Gomes de Moraes
- Department of BotanyInstitute of Biological SciencesFederal University of Goiás1974690-900Goiânia, GoiásBrazil
| | - Štěpán Janeček
- School of Biological SciencesThe University of Western Australia35 Stirling HighwayCrawley (Perth)WA 6009Australia
| | - Hans Lambers
- School of Biological SciencesThe University of Western AustraliaCrawley (Perth)WAAustralia
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Nishanth Tharayil
- Department of Plant and Environmental SciencesClemson UniversityClemsonSC29634USA
| | - M. Luke McCormack
- Center for Tree ScienceMorton Arboretum, 4100 Illinois Rt. 53LisleIL60532USA
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10
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Arnaud M, Morris PJ, Baird AJ, Dang H, Nguyen TT. Fine root production in a chronosequence of mature reforested mangroves. THE NEW PHYTOLOGIST 2021; 232:1591-1602. [PMID: 34018616 DOI: 10.1111/nph.17480] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Mangroves are among the world's most carbon-dense ecosystems, but have suffered extensive deforestation, prompting reforestation projects. The effects of mangrove reforestation on belowground carbon dynamics are poorly understood. In particular, we do not know how fine root production develops following mangrove reforestation, despite fine root production being a major carbon sink and an important control of mangrove soil accretion. Using minirhizotrons, we investigated fine root production and its depth variation along a chronosequence of mature Vietnamese mangroves. Our results showed that fine root production decreases strongly with stand age in the uppermost 32 cm of our soil profiles. In younger mangrove stands, fine root production declines with depth, possibly due to a vertical gradient in soil nutrient availability; while root production in the oldest stand is low at all depths and exhibits no clear vertical pattern. A major fraction of fine root production occurs deeper than 30 cm, depths that are commonly omitted from calculations of mangrove carbon budgets. Younger mangroves may accrue shallow soil organic matter faster than older mangroves. Therefore, root productivity and forest stand age should be accounted for when forecasting mangrove carbon budgets and resistance to sea-level rise.
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Affiliation(s)
- Marie Arnaud
- Laboratoire Environnement et Ressources des Pertuis Charentais (LER-PC), IFREMER, La Tremblade, BP133, France
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Paul J Morris
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Andy J Baird
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Huyen Dang
- Faculty of Geology and Petroleum Engineering, Ho Chí Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet St., Dist. 10, Ho Chí Minh, Vietnam
| | - Tai Tue Nguyen
- VNU-University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
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11
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Primka EJ, Adams TS, Buck A, Eissenstat DM. Topographical shifts in fine root lifespan in a mixed, mesic temperate forest. PLoS One 2021; 16:e0254672. [PMID: 34260660 PMCID: PMC8279377 DOI: 10.1371/journal.pone.0254672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/30/2021] [Indexed: 11/18/2022] Open
Abstract
Root lifespan, often is estimated in landscape- and ecosystem-level carbon models using linear approximations. In water manipulation experiments, fine root lifespan can vary with soil water content. Soil water content is generally structured by complex topography, which is largely unaccounted for in landscape- and ecosystem-scale carbon models. Topography governs the range of soil water content experienced by roots which may impact their lifespan. We hypothesized that root lifespan varied nonlinearly across a temperate, mesic, forested catchment due to differences in soil water content associated with topographic position. We expected regions of the landscape that were too wet or too dry would have soils that were not optimal for roots and thus result in shorter root lifespans. Specifically, we hypothesized that root lifespan would be longest in areas that consistently had soil water content in the middle of the soil water content spectrum, while in soils at either very low or very high soil water content, root lifespan would be relatively short. We tested this hypothesis by collecting and analyzing two years of minirhizotron and soil moisture data in plots widely distributed in the Shale Hills catchment of the Susquehanna-Shale Hills Critical Zone Observatory in Pennsylvania. We found that fine root lifespans were longer in traditionally wetter topographic regions, but detected no short term (biweekly) effect of soil moisture on root lifespan. Additionally, depth in soil, soil series, slope face orientation, and season of birth strongly affected root lifespans across the catchment. In contrast, lifespan was unaffected by root diameter or mycorrhizal association. Failure to account for these variables could result in erroneous estimates of fine root lifespan and, consequentially, carbon flux in temperate forested regions.
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Affiliation(s)
- Edward J. Primka
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Graduate Program in Ecology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Thomas S. Adams
- Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Alexandra Buck
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - David M. Eissenstat
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Graduate Program in Ecology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
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12
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Li X, Zhang C, Zhang B, Wu D, Zhu D, Zhang W, Ye Q, Yan J, Fu J, Fang C, Ha D, Fu S. Nitrogen deposition and increased precipitation interact to affect fine root production and biomass in a temperate forest: Implications for carbon cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144497. [PMID: 33418324 DOI: 10.1016/j.scitotenv.2020.144497] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Fine roots connect belowground and aboveground systems and help regulate the carbon balance of terrestrial ecosystems by providing nutrients and water for plants. To evaluate the effects of atmospheric nitrogen (N) deposition and increased precipitation on fine root production and standing biomass in a temperate deciduous forest in central China, we conducted a 6-year experiment. From 2013 to 2018, we applied N (25 kg N ha-1 yr-1) and water (336 mm, 30% of the ambient annual precipitation) above the forest canopy, and we quantified fine root production and biomass in 2017 and 2018. At 0-10 cm soil depth, the statistical interaction between addition of N and water was not significant in terms of fine root production or biomass. At 0-10 cm soil depth, N addition significantly increased fine root production by 18.1%, but did not affect fine root biomass. Water addition significantly increased fine root production and biomass by 13.6 and 17.0%, respectively. Both N and water addition had significant direct positive effects on fine root production, and water addition had indirect positive effects on fine root biomass through decreasing soil NO3- concentration. At 10-30 cm soil depth, the statistical interaction between N addition and water addition was significant in terms of both fine root production and biomass, i.e., the positive effect of N addition was reduced by water addition, and vice versa. These findings indicate that fine roots and therefore belowground carbon storage may have complex responses to increases in atmospheric N deposition and changes in precipitation predicted for the future. The findings also suggest that results obtained from experiments that consider only one independent variable (e.g., N input or water input) and only one soil depth should be interpreted with caution.
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Affiliation(s)
- Xiaowei Li
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
| | - Chenlu Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China.
| | - Beibei Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Di Wu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Dandan Zhu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Wei Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Juemin Fu
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | | | - Denglong Ha
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | - Shenglei Fu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
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13
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Pierre S, Litton CM, Giardina CP, Sparks JP, Fahey TJ. Mean annual temperature influences local fine root proliferation and arbuscular mycorrhizal colonization in a tropical wet forest. Ecol Evol 2020; 10:9635-9646. [PMID: 33005336 PMCID: PMC7520179 DOI: 10.1002/ece3.6561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 05/11/2020] [Accepted: 05/21/2020] [Indexed: 11/25/2022] Open
Abstract
Mean annual temperature (MAT) is an influential climate factor affecting the bioavailability of growth-limiting nutrients nitrogen (N) and phosphorus (P). In tropical montane wet forests, warmer MAT drives higher N bioavailability, while patterns of P availability are inconsistent across MAT. Two important nutrient acquisition strategies, fine root proliferation into bulk soil and root association with arbuscular mycorrhizal fungi, are dependent on C availability to the plant via primary production. The case study presented here tests whether variation in bulk soil N bioavailability across a tropical montane wet forest elevation gradient (5.2°C MAT range) influences (a) morphology fine root proliferation into soil patches with elevated N, P, and N+P relative to background soil and (b) arbuscular mycorrhizal fungal (AMF) colonization of fine roots in patches. We created a fully factorial fertilized root ingrowth core design (N, P, N+P, unfertilized control) representing soil patches with elevated N and P bioavailability relative to background bulk soil. Our results show that percent AMF colonization of roots increased with MAT (r 2 = .19, p = .004), but did not respond to fertilization treatments. Fine root length (FRL), a proxy for root foraging, increased with MAT in N+P-fertilized patches only (p = .02), while other fine root morphological parameters did not respond to the gradient or fertilized patches. We conclude that in N-rich, fine root elongation into areas with elevated N and P declines while AMF abundance increases with MAT. These results indicate a tradeoff between P acquisition strategies occurring with changing N bioavailability, which may be influenced by higher C availability with warmer MAT.
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Affiliation(s)
- Suzanne Pierre
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York USA
- Department of Integrative Biology University of California, Berkeley Berkeley California USA
| | - Creighton M Litton
- Department of Natural Resources and Environmental Management University of Hawai'i at Manoa Honolulu Hawai'i USA
| | - Christian P Giardina
- Institute of Pacific Islands Forestry Pacific Southwest Research Station US Forest Service Hilo Hawaii USA
| | - Jed P Sparks
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York USA
| | - Timothy J Fahey
- Department of Natural Resources Cornell University Ithaca New York USA
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14
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Effects of Summer Drought on the Fine Root System of Five Broadleaf Tree Species along a Precipitation Gradient. FORESTS 2020. [DOI: 10.3390/f11030289] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
While much research has addressed the aboveground response of trees to climate warming and related water shortage, not much is known about the drought sensitivity of the fine root system, in particular of mature trees. This study investigates the response of topsoil (0–10 cm) fine root biomass (FRB), necromass (FRN), and fine root morphology of five temperate broadleaf tree species (Acer platanoides L., Carpinus betulus L., Fraxinus excelsior L., Quercus petraea (Matt.) Liebl., Tilia cordata Mill.) to a reduction in water availability, combining a precipitation gradient study (nine study sites; mean annual precipitation (MAP): 920–530 mm year−1) with the comparison of a moist period (average spring conditions) and an exceptionally dry period in the summer of the subsequent year. The extent of the root necromass/biomass (N/B) ratio increase was used as a measure of the species’ belowground sensitivity to water deficits. We hypothesized that the N/B ratio increases with long-term (precipitation gradient) and short-term reductions (moist vs. dry period) of water availability, while FRB changes only a little. In four of the five species (exception: A. platanoides), FRB did not change with a reduction in MAP, whereas FRN and N/B ratio increased toward the dry sites under ample water supply (exception: Q. petraea). Q. petraea was also the only species not to reduce root tip frequency after summer drought. Different slopes of the N/B ratio-MAP relation similarly point at a lower belowground drought sensitivity of Q. petraea than of the other species. After summer drought, all species lost the MAP dependence of the N/B ratio. Thus, fine root mortality increased more at the moister than the drier sites, suggesting a generally lower belowground drought sensitivity of the drier stands. We conclude that the five species differ in their belowground drought response. Q. petraea follows the most conservative soil exploration strategy with a generally smaller FRB and more drought-tolerant fine roots, as it maintains relatively constant FRB, FRN, and morphology across spatial and temporal dimensions of soil water deficits.
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15
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Xu Y, Zhang Y, Yang J, Lu Z. Influence of tree functional diversity and stand environment on fine root biomass and necromass in four types of evergreen broad-leaved forests. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2019.e00832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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16
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Zwetsloot MJ, Goebel M, Paya A, Grams TEE, Bauerle TL. Specific spatio-temporal dynamics of absorptive fine roots in response to neighbor species identity in a mixed beech-spruce forest. TREE PHYSIOLOGY 2019; 39:1867-1879. [PMID: 31504991 DOI: 10.1093/treephys/tpz086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/07/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Absorptive fine roots are an important driver of soil biogeochemical cycles. Yet, the spatio-temporal dynamics of those roots in the presence of neighboring species remain poorly understood. The aim of this study was to analyze shifts in absorptive fine-root traits in monoculture or mixtures of Fagus sylvatica [L.] and Picea abies [L.] Karst. We hypothesized that root competition would be higher under single-species than mixed-species interactions, leading to changes in (i) root survivorship, diameter and respiration and (ii) spatio-temporal patterns of root growth and death. Using minirhizotron methods, we monitored the timing and location of absorptive fine-root growth and death at an experimental forest in southern Germany from 2011 to 2013. We also measured root respiration in the spring and fall seasons of 2012 and 2013. Our findings show that the absorptive fine roots of F. sylvatica had a 50% higher risk of root mortality and higher respiration rates in the single-species compared to mixed-species zones. These results support our hypothesis that root competition is less intense for F. sylvatica in mixture versus monoculture. We were unable to find confirmation for the same hypothesis for P. abies. To analyze spatio-temporal patterns of absorptive fine-root production and mortality, we used a mixed-effects model considering root depth (space) and seasons (time) simultaneously. This analysis showed that F. sylvatica shifts root production towards shallower soil layers in mixed-species stands, besides significant seasonal fluctuations in root production depths for both species. Ultimately, the impact of neighbor species identity on root traits observed in this study has important implications for where, when and how fast root-facilitated carbon cycling takes place in single-species versus mixed-species forests. In addition, our study highlights the need for inclusion of absorptive fine-root spatio-temporal dynamics when examining belowground plant interactions and biogeochemical cycles.
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Affiliation(s)
- Marie J Zwetsloot
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
- Soil Biology Group, Wageningen University, Droevendaalsesteeg 3, 6708 PB Wageningen, the Netherlands
| | - Marc Goebel
- Department of Natural Resources, Cornell University, 111 Fernow Hall, Ithaca, NY 14853, USA
| | - Alex Paya
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technical University of Munich, Am Hochanger 13, 85354 Freising, Germany
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
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17
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Dai L, Ke X, Du Y, Zhang F, Li Y, Li Q, Lin L, Peng C, Shu K, Cao G, Guo X. Nitrogen controls the net primary production of an alpine Kobresia meadow in the northern Qinghai-Tibet Plateau. Ecol Evol 2019; 9:8865-8875. [PMID: 31410286 PMCID: PMC6686337 DOI: 10.1002/ece3.5442] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 11/08/2022] Open
Abstract
Net primary production (NPP) is a fundamental property of natural ecosystems. Understanding the temporal variations of NPP could provide new insights into the responses of communities to environmental factors. However, few studies based on long-term field biomass measurements have directly addressed this subject in the unique environment of the Qinghai-Tibet plateau (QTP). We examined the interannual variations of NPP during 2008-2015 by monitoring both aboveground net primary productivity (ANPP) and belowground net primary productivity (BNPP), and identified their relationships with environmental factors with the general linear model (GLM) and structural equation model (SEM). In addition, the interannual variation of root turnover and its controls were also investigated. The results show that the ANPP and BNPP increased by rates of 15.01 and 143.09 g/m2 per year during 2008-2015, respectively. BNPP was mainly affected by growing season air temperature (GST) and growing season precipitation (GSP) rather than mean annual air temperature (MAT) or mean annual precipitation (MAP), while ANPP was only controlled by GST. In addition, available nitrogen (AN) was significantly positively associated with BNPP and ANPP. Root turnover rate averaged 30%/year, increased with soil depth, and was largely controlled by GST. Our results suggest that alpine Kobresia meadow was an N-limited ecosystem, and the NPP on the QTP might increase further in the future in the context of global warming and nitrogen deposition.
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Affiliation(s)
- Licong Dai
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
- University of Chinese Academy of ScienceBeijingChina
| | - Xun Ke
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
- University of Chinese Academy of ScienceBeijingChina
| | - Yangong Du
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
| | - Fawei Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
- College of Life SciencesLuoyang Normal UniversityLuoyangChina
| | - Yikang Li
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
| | - Qian Li
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
| | - Li Lin
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
| | - Cuoji Peng
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
- University of Chinese Academy of ScienceBeijingChina
| | - Kai Shu
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
- University of Chinese Academy of ScienceBeijingChina
| | - Guangmin Cao
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
| | - Xiaowei Guo
- Key Laboratory of Adaptation and Evolution of Plateau Botany, Northwest Institute of Plateau BiologyChinese Academy of ScienceXiningChina
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18
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Effect of Deadwood on Ectomycorrhizal Colonisation of Old-Growth Oak Forests. FORESTS 2019. [DOI: 10.3390/f10060480] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the importance of coarse woody debris (CWD) for species diversity is recognized, the effects of coarse woody debris decay class on species composition have received little attention. We examined how the species composition of ectomycorrhizal fungi (ECM) changes with CWD decay. We describe ectomycorrhizal root tips and the diversity of mycorrhizal fungal species at three English oak (Quercus robur L.) sites. DNA barcoding revealed a total of 17 ECM fungal species. The highest degree of mycorrhizal colonization was found in CWDadvanced (27.2%) and CWDearly (27.1%). Based on exploration types, ectomycorrhizae were classified with respect to ecologically relevant soil features. The short distance type was significantly correlated with soil P2O5, while the contact type was correlated with soil C/N. The lowest mean content of soil Corg was found in the CWDabsent site. The difference in total soil N between sites decreased with increasing CWD decomposition, whereas total C/N increased correspondingly. In this study we confirmed that soil CWD stimulates ectomycorrhizal fungi, representing contact or short-distance exploration types of mycelium.
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19
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Ectomycorrhizal Colonisation in Declining Oak Stands on the Krotoszyn Plateau, Poland. FORESTS 2019. [DOI: 10.3390/f10010030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe the ectomycorrhizal (ECM) root tips and the diversity of mycorrhizal fungal species at three English oak (Quercus robur) sites (two 120 year old sites and one 60 year old site). The three oak stands in decline, located in western Poland, were characterized by a low degree of vital ECM colonization: 30.2%, 29.1% and 25.6% at Krotoszyn (K), Piaski (P) and Karczma Borowa (KB), respectively. DNA (ITS) barcoding revealed a total of 18 ECM fungal species. Based on exploration types, ectomycorrhizae were classified with respect to ecologically relevant features. The contact type was significantly correlated with C:N and Corg, while the short distance type was correlated with Ca, phosphorus (P2O5) and pH. The medium distance exploration type was significantly correlated with fine-grained soil particle size fractions: coarse silt (0.05–0.02 mm) and fine silt (0.02–0.002 mm), and clay (<0.002 mm). The long distance type showed a similar pattern to the medium distance smooth type, but was also correlated with nitrate (N). The values of biometric root parameters of oak trees at the analysed forest sites were arranged as follows: K > P > KB, and were opposite to the condition of the tree crowns. A negative correlation of vital ECM root tip abundance with the crown health status of oaks was observed, whereas higher ECM diversity reflected better crown health in the oak stands studied.
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20
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Wang P, Yang Y, Mou P, Zhao Q, Li Y. Local root growth and death are mediated by contrasts in nutrient availability and root quantity between soil patches. Proc Biol Sci 2018; 285:20180699. [PMID: 30209222 PMCID: PMC6158519 DOI: 10.1098/rspb.2018.0699] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/21/2018] [Indexed: 11/12/2022] Open
Abstract
Plants are thought to be able to regulate local root growth according to its overall nutrient status as well as nutrient contents in a local substrate patch. Therefore, root plastic responses to environmental changes are probably co-determined by local responses of root modules and systematic control of the whole plant. Recent studies showed that the contrast in nutrient availability between different patches could significantly influence the growth and death of local roots. In this study, we further explored, beside nutrient contrast, whether root growth and death in a local patch are also affected by relative root quantity in the patch. We conducted a split-root experiment with different splitting ratios of roots of Canada goldenrod (Solidago canadensis) individuals, as well as high- (5× Hoagland solution versus water) or low- (1× Hoagland solution versus water) contrast nutrient conditions for the split roots. The results showed that root growth decreased in nutrient-rich patches but increased in nutrient-poor patches when more roots co-occurred in the same patches, irrespective of nutrient contrast condition. Root mortality depended on contrasts in both root quantity and nutrients: in the high-nutrient-contrast condition, it increased in nutrient-rich patches but decreased in nutrient-poor patches with increasing root proportion; while in the low-nutrient-contrast condition, it showed the opposite trend. These results demonstrated that root growth and death dynamics were affected by the contrast in both nutrient availability and root quantity between patches. Our study provided ecological evidence that local root growth and death are mediated by both the responses of root modules to a nutrient patch and the whole-plant nutrient status, suggesting that future work investigating root production and turnover should take into account the degree of heterogeneity in nutrient and root distribution.
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Affiliation(s)
- Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Yan Yang
- College of Life Sciences, Beijing Normal University, Beijing, People's Republic of China
- Wuhu TianJiaBing Experimental High School, Wuhu, People's Republic of China
| | - Pu Mou
- College of Life Sciences, Beijing Normal University, Beijing, People's Republic of China
| | - Qingzhou Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Yunbin Li
- College of Environmental and Safety Engineering, Shenyang University of Chemical Technology, Shenyang, People's Republic of China
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Lugo MA, Menoyo E, Allione LR, Negritto MA, Henning JA, Anton AM. Arbuscular mycorrhizas and dark septate endophytes associated with grasses from the Argentine Puna. Mycologia 2018; 110:654-665. [DOI: 10.1080/00275514.2018.1492846] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Mónica A. Lugo
- Laboratorio de Micología, Diversidad e Interacciones Fúngicas, Área de Ecología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Box 4, 2do. Piso, Bloque I, Rectorado UNSL, San Luis, Argentina
- IMIBIO-SL-CONICET, Universidad Nacional de San Luis, Ejército de los Andes 950, 5700, San Luis, Argentina
| | - Eugenia Menoyo
- Laboratorio de Micología, Diversidad e Interacciones Fúngicas, Área de Ecología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Box 4, 2do. Piso, Bloque I, Rectorado UNSL, San Luis, Argentina
- GEA-IMASL-CONICET, Universidad Nacional de San Luis, San Luis, Argentina
| | - Lucía Risio Allione
- Laboratorio de Micología, Diversidad e Interacciones Fúngicas, Área de Ecología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Box 4, 2do. Piso, Bloque I, Rectorado UNSL, San Luis, Argentina
- IMIBIO-CONICET, Universidad Nacional de San Luis, San Luis, Argentina
| | - María A. Negritto
- Facultad de Ciencias Básicas, Universidad del Magdalena, Carrera 32 No. 22-08, Apartado Postal 2-1-21630, Santa Marta, Colombia
| | - Jeremiah A. Henning
- Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Ana M. Anton
- IMBIV-CONICET, Universidad Nacional de Córdoba, CC 495, 5000 Córdoba, Argentina
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Salguero‐Gómez R, Violle C, Gimenez O, Childs D, Fox C. Delivering the promises of trait-based approaches to the needs of demographic approaches, and vice versa. Funct Ecol 2018; 32:1424-1435. [PMID: 30034074 PMCID: PMC6049886 DOI: 10.1111/1365-2435.13148] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/22/2018] [Indexed: 11/28/2022]
Abstract
Few facets of biology vary more than functional traits and life-history traits. To explore this vast variation, functional ecologists and population ecologists have developed independent approaches that identify the mechanisms behind and consequences of trait variation.Collaborative research between researchers using trait-based and demographic approaches remains scarce. We argue that this is a missed opportunity, as the strengths of both approaches could help boost the research agendas of functional ecology and population ecology.This special feature, which spans three journals of the British Ecological Society due to its interdisciplinary nature, showcases state-of-the-art research applying trait-based and demographic approaches to examine relationships between organismal function, life history strategies and population performance across multiple kingdoms. Examples include the exploration of how functional trait × environment interactions affect vital rates and thus explain population trends and species occurrence; the coordination of seed traits and dispersal ability with the pace of life in plants; the incorporation of functional traits in dynamic energy budget models; or the discovery of linkages between microbial functional traits and the fast-slow continuum.Despite their historical isolation, collaborative work between functional ecologists and population ecologists could unlock novel research pathways. We call for an integrative research agenda to evaluate which and when traits are functional, as well as their ability to describe and predict life history strategies and population dynamics. We highlight promising, complementary research avenues to overcome current limitations. These include a more explicit linkage of selection gradients in the context of functional trait-vital rate relationships, and the implementation of standardised protocols to track changes in traits and vital rates over time at the same location and individuals, thus allowing for the explicit incorporation of trade-offs in analyses of covariation of functional traits and life-history traits.
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Affiliation(s)
- Roberto Salguero‐Gómez
- Department of ZoologyUniversity of OxfordOxfordUK
- Evolutionary Biodemography LaboratoryMax Planck Institute for Demographic ResearchRostockGermany
- Centre for Biodiversity and Conservation ScienceUniversity of QueenslandSt LuciaQldAustralia
| | - Cyrille Violle
- CEFE, CNRSUniv MontpellierUniv Paul Valéry Montpellier 3, EPHE, IRDMontpellierFrance
| | - Olivier Gimenez
- CEFE, CNRSUniv MontpellierUniv Paul Valéry Montpellier 3, EPHE, IRDMontpellierFrance
| | - Dylan Childs
- Department of Animal & Plant SciencesThe University of SheffieldSheffieldUK
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Barczi JF, Rey H, Griffon S, Jourdan C. DigR: a generic model and its open source simulation software to mimic three-dimensional root-system architecture diversity. ANNALS OF BOTANY 2018; 121:1089-1104. [PMID: 29506106 PMCID: PMC5906913 DOI: 10.1093/aob/mcy018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/25/2018] [Indexed: 05/04/2023]
Abstract
Background and Aims Many studies exist in the literature dealing with mathematical representations of root systems, categorized, for example, as pure structure description, partial derivative equations or functional-structural plant models. However, in these studies, root architecture modelling has seldom been carried out at the organ level with the inclusion of environmental influences that can be integrated into a whole plant characterization. Methods We have conducted a multidisciplinary study on root systems including field observations, architectural analysis, and formal and mathematical modelling. This integrative and coherent approach leads to a generic model (DigR) and its software simulator. Architecture analysis applied to root systems helps at root type classification and architectural unit design for each species. Roots belonging to a particular type share dynamic and morphological characteristics which consist of topological and geometric features. The DigR simulator is integrated into the Xplo environment, with a user interface to input parameter values and make output ready for dynamic 3-D visualization, statistical analysis and saving to standard formats. DigR is simulated in a quasi-parallel computing algorithm and may be used either as a standalone tool or integrated into other simulation platforms. The software is open-source and free to download at http://amapstudio.cirad.fr/soft/xplo/download. Key Results DigR is based on three key points: (1) a root-system architectural analysis, (2) root type classification and modelling and (3) a restricted set of 23 root type parameters with flexible values indexed in terms of root position. Genericity and botanical accuracy of the model is demonstrated for growth, branching, mortality and reiteration processes, and for different root architectures. Plugin examples demonstrate the model's versatility at simulating plastic responses to environmental constraints. Outputs of the model include diverse root system structures such as tap-root, fasciculate, tuberous, nodulated and clustered root systems. Conclusions DigR is based on plant architecture analysis which leads to specific root type classification and organization that are directly linked to field measurements. The open source simulator of the model has been included within a friendly user environment. DigR accuracy and versatility are demonstrated for growth simulations of complex root systems for both annual and perennial plants.
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Affiliation(s)
- Jean-François Barczi
- CIRAD, UMR AMAP, Montpellier, France
- AMAP, Univ Montpellier, CIRAD, CNRS, INRA, IRD, Montpellier, France
| | - Hervé Rey
- CIRAD, UMR AMAP, Montpellier, France
- AMAP, Univ Montpellier, CIRAD, CNRS, INRA, IRD, Montpellier, France
| | - Sébastien Griffon
- CIRAD, UMR AMAP, Montpellier, France
- AMAP, Univ Montpellier, CIRAD, CNRS, INRA, IRD, Montpellier, France
| | - Christophe Jourdan
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco & Sols, Univ Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, Montpellier, France
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Dong J, Jones RH, Mou P. Relationships between Nutrient Heterogeneity, Root Growth, and Hormones: Evidence for Interspecific Variation. PLANTS (BASEL, SWITZERLAND) 2018; 7:E15. [PMID: 29495558 PMCID: PMC5874604 DOI: 10.3390/plants7010015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/13/2018] [Accepted: 02/15/2018] [Indexed: 11/16/2022]
Abstract
(1) Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2) Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species-Callistephus chinensis, Solidago canadensis, Ailanthus altissima, Oryza sativa-to two nitrogen types (NO₃- or NH₄⁺), three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively) and two ways of nitrogen application (stable vs. variable). The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa, density of the 1st order laterals, seminal root number for O. sativa, the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside). (3) Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4) Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.
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Affiliation(s)
- Jia Dong
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Engineering, Beijing Normal University, Beijing 100875, China.
| | - Robert H Jones
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634, USA.
| | - Pu Mou
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Engineering, Beijing Normal University, Beijing 100875, China.
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Chen W, Koide RT, Eissenstat DM. Nutrient foraging by mycorrhizas: From species functional traits to ecosystem processes. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13041] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Weile Chen
- Intercollege Graduate Degree Program in Ecology The Pennsylvania State University University Park PA USA
- Department of Ecosystem Science and Management The Pennsylvania State University University Park PA USA
| | - Roger T. Koide
- Intercollege Graduate Degree Program in Ecology The Pennsylvania State University University Park PA USA
- Department of Biology Brigham Young University Provo UT USA
| | - David M. Eissenstat
- Intercollege Graduate Degree Program in Ecology The Pennsylvania State University University Park PA USA
- Department of Ecosystem Science and Management The Pennsylvania State University University Park PA USA
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26
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Wang C, Geng Z, Chen Z, Li J, Guo W, Zhao TH, Cao Y, Shen S, Jin D, Li MH. Six-Year Nitrogen-Water Interaction Shifts the Frequency Distribution and Size Inequality of the First-Order Roots of Fraxinus mandschurica in a Mixed Mature Pinus koraiensis Forest. FRONTIERS IN PLANT SCIENCE 2017; 8:1691. [PMID: 29018474 PMCID: PMC5622955 DOI: 10.3389/fpls.2017.01691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
The variation in fine root traits in terms of size inequality at the individual root level can be identified as a strategy for adapting to the drastic changes in soil water and nutrient availabilities. The Gini and Lorenz asymmetry coefficients have been applied to describe the overall degree of size inequality, which, however, are neglected when conventional statistical means are calculated. Here, we used the Gini coefficient, Lorenz asymmetry coefficient and statistical mean in an investigation of Fraxinus mandschurica roots in a mixed mature Pinus koraiensis forest on Changbai Mountain, China. We analyzed 967 individual roots to determine the responses of length, diameter and area of the first-order roots and of branching intensity to 6 years of nitrogen addition (N), rainfall reduction (W) and their combination (NW). We found that first-order roots had a significantly greater average length and area but had smaller Gini coefficients in NW plots compared to in control plots (CK). Furthermore, the relationship between first-order root length and branching intensity was negative in CK, N, and W plots but positive in NW plots. The Lorenz asymmetry coefficient was >1 for the first-order root diameter in NW and W plots as well as for branching intensity in N plots. The bimodal frequency distribution of the first-order root length in NW plots differed clearly from the unimodal one in CK, N, and W plots. These results demonstrate that not only the mean but also the variation and the distribution mode of the first-order roots of F. mandschurica respond to soil nitrogen and water availability. The changes in size inequality of the first-order root traits suggest that Gini and Lorenz asymmetry coefficients can serve as informative parameters in ecological investigations of roots to improve our ability to predict how trees will respond to a changing climate at the individual root level.
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Affiliation(s)
- Cunguo Wang
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Zhenzhen Geng
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Zhao Chen
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Jiandong Li
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Wei Guo
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Tian-Hong Zhao
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Ying Cao
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Si Shen
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Daming Jin
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Mai-He Li
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
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Schmidt JE, Gaudin ACM. Toward an Integrated Root Ideotype for Irrigated Systems. TRENDS IN PLANT SCIENCE 2017; 22:433-443. [PMID: 28262426 DOI: 10.1016/j.tplants.2017.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/23/2017] [Accepted: 02/06/2017] [Indexed: 05/24/2023]
Abstract
Breeding towards root-centric ideotypes can be a relatively quick trait-based strategy to improve crop resource use efficiency. Irrigated agriculture represents a crucial and expanding sector, but its unique parameters require traits distinct from previously proposed rainfed ideotypes. We propose a novel irrigated ideotype that integrates traits across multiple scales to enhance resource use efficiency in irrigated agroecosystems, where resources are concentrated in a relatively shallow 'critical zone'. Unique components of this ideotype include rapid transplant recovery and establishment, enhanced exploitation of localized resource hotspots, adaptive physiological regulation, maintenance of hydraulic conductivity, beneficial rhizosphere interactions, and salinity/waterlogging avoidance. If augmented by future research, this target could help to enhance agricultural sustainability in irrigated agroecosystems by guiding the creation of resource-efficient cultivars.
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Affiliation(s)
- Jennifer E Schmidt
- Department of Plant Sciences, University of California (UC) Davis, Davis, CA 95616, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California (UC) Davis, Davis, CA 95616, USA.
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28
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Rabert C, Reyes-Díaz M, Corcuera LJ, Bravo LA, Alberdi M. Contrasting nitrogen use efficiency of Antarctic vascular plants may explain their population expansion in Antarctica. Polar Biol 2017. [DOI: 10.1007/s00300-017-2079-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Nietfeld H, Prenzel J, Helmisaari HS, Polle A, Beese F. Modeling of mineral nutrient uptake of spruce tree roots as affected by the ion dynamics in the rhizosphere: Upscaling of model results to field plot scale. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2016.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fuchslueger L, Bahn M, Hasibeder R, Kienzl S, Fritz K, Schmitt M, Watzka M, Richter A. Drought history affects grassland plant and microbial carbon turnover during and after a subsequent drought event. THE JOURNAL OF ECOLOGY 2016; 104:1453-1465. [PMID: 27609992 PMCID: PMC4996329 DOI: 10.1111/1365-2745.12593] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 04/18/2016] [Indexed: 05/07/2023]
Abstract
Drought periods are projected to become more severe and more frequent in many European regions. While effects of single strong droughts on plant and microbial carbon (C) dynamics have been studied in some detail, impacts of recurrent drought events are still little understood.We tested whether the legacy of extreme experimental drought affects responses of plant and microbial C and nitrogen (N) turnover to further drought and rewetting. In a mountain grassland, we conducted a 13C pulse-chase experiment during a naturally occurring drought and rewetting event in plots previously exposed to experimental droughts and in ambient controls (AC). After labelling, we traced 13C below-ground allocation and incorporation into soil microbes using phospholipid fatty acid biomarkers.Drought history (DH) had no effects on the standing shoot and fine root plant biomass. However, plants with experimental DH displayed decreased shoot N concentrations and increased fine root N concentrations relative to those in AC. During the natural drought, plants with DH assimilated and allocated less 13C below-ground; moreover, fine root respiration was reduced and not fuelled by fresh C compared to plants in AC.Regardless of DH, microbial biomass remained stable during natural drought and rewetting. Although microbial communities initially differed in their composition between soils with and without DH, they responded to the natural drought and rewetting in a similar way: gram-positive bacteria increased, while fungal and gram-negative bacteria remained stable. In soils with DH, a strongly reduced uptake of recent plant-derived 13C in microbial biomarkers was observed during the natural drought, pointing to a smaller fraction of active microbes or to a microbial community that is less dependent on plant C. Synthesis. Drought history can induce changes in above- vs. below-ground plant N concentrations and affect the response of plant C turnover to further droughts and rewetting by decreasing plant C uptake and below-ground allocation. DH does not affect the responses of the microbial community to further droughts and rewetting, but alters microbial functioning, particularly the turnover of recent plant-derived carbon, during and after further drought periods.
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Affiliation(s)
- Lucia Fuchslueger
- Department of Microbiology and Ecosystem Science University of Vienna Althanstrasse 14A-1090 Vienna Austria; Present address: National Institute for Amazonian Research (INPA) Av. André Araujo 2936 Aleixo Manaus Amazonas CEP: 69067-375 Brazil
| | - Michael Bahn
- Institute of Ecology University of Innsbruck Sternwartestrasse 15 A-6020 Innsbruck Austria
| | - Roland Hasibeder
- Institute of Ecology University of Innsbruck Sternwartestrasse 15 A-6020 Innsbruck Austria
| | - Sandra Kienzl
- Department of Microbiology and Ecosystem Science University of Vienna Althanstrasse 14 A-1090 Vienna Austria
| | - Karina Fritz
- Institute of Ecology University of Innsbruck Sternwartestrasse 15 A-6020 Innsbruck Austria
| | - Michael Schmitt
- Institute of Ecology University of Innsbruck Sternwartestrasse 15 A-6020 Innsbruck Austria
| | - Margarete Watzka
- Department of Microbiology and Ecosystem Science University of Vienna Althanstrasse 14 A-1090 Vienna Austria
| | - Andreas Richter
- Department of Microbiology and Ecosystem Science University of Vienna Althanstrasse 14 A-1090 Vienna Austria
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31
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Peltier DMP, Fell M, Ogle K. Legacy effects of drought in the southwestern United States: A multi‐species synthesis. ECOL MONOGR 2016. [DOI: 10.1002/ecm.1219] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Drew M. P. Peltier
- Department of Biological Sciences Northern Arizona University FlagstaffArizona 86011USA
| | - Michael Fell
- Informatics and Computing Program Northern Arizona University FlagstaffArizona 86011USA
- School of Life Sciences Arizona State University TempeArizona 85287USA
| | - Kiona Ogle
- Department of Biological Sciences Northern Arizona University FlagstaffArizona 86011USA
- Informatics and Computing Program Northern Arizona University FlagstaffArizona 86011USA
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32
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Li Y, Kronzucker HJ, Shi W. Microprofiling of nitrogen patches in paddy soil: Analysis of spatiotemporal nutrient heterogeneity at the microscale. Sci Rep 2016; 6:27064. [PMID: 27265522 PMCID: PMC4893627 DOI: 10.1038/srep27064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 05/16/2016] [Indexed: 11/24/2022] Open
Abstract
Flooded paddy soil ecosystems in the tropics support the cultivation of the majority of the world's leading crop, rice, and nitrogen (N) availability in the paddy-soil rooting zone limits rice production more than any other nutritional factor. Yet, little is known about the dynamic response of paddy soil to N-fertiliser application, in terms of horizontal and vertical patchiness in N distribution and transformation. Here, we present a microscale analysis of the profile of ammonium (NH4(+)) and nitrate (NO3(-)), nitrification, oxygen (O2water and O2soil), and pH (pHwater and pHsoil) in paddy soils, collected from two representative rice-production areas in subtropical China. NH4(+) and NO3(-) exhibited dramatic spatiotemporal profiles within N patches on the microscale. We show that pHsoil became constant at 1.0-3.5 mm depth, and O2soil became undetectable at 1.7-4.0 mm. Fertiliser application significantly increased pH, and decreased O2, within N patches. Path analysis showed that the factors governing nitrification scaled in the order: pHwater > pHsoil > NH4(+) > O2water > NO3(-) > O2soil. We discuss the soil properties that decide the degree of nutrient patchiness within them and argue that such knowledge is critical to intelligent appraisals of nutrient-use efficiencies in the field.
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Affiliation(s)
- Yilin Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Herbert J. Kronzucker
- Department of Biological Sciences, University of Toronto, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
| | - Weiming Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
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Artacho P, Bonomelli C. Changes in fine-root production, phenology and spatial distribution in response to N application in irrigated sweet cherry trees. TREE PHYSIOLOGY 2016; 36:601-17. [PMID: 26888890 PMCID: PMC4886287 DOI: 10.1093/treephys/tpw002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 01/01/2016] [Indexed: 06/05/2023]
Abstract
Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha(-1)), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110-180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70-80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source-sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees.
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Affiliation(s)
- Pamela Artacho
- Ph.D. Program in Agricultural Sciences, Agronomy and Forestry Faculty, Pontifical Catholic University of Chile, Vicuña Mackenna 4860, 7820436-Macul, Región Metropolitana, Chile;
| | - Claudia Bonomelli
- Pomology and Enology Department, Pontifical Catholic University of Chile, Vicuña Mackenna 4860, 7820436-Macul, Región Metropolitana, Chile
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34
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Majdi H, Kangas P. Demography of fine roots in response to nutrient applications in a Norway spruce stand in southwestern Sweden. ECOSCIENCE 2016. [DOI: 10.1080/11956860.1997.11682396] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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35
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Hendrick RL, Pregitzer KS. The relationship between fine root demography and the soil environment in northern hardwood forests. ECOSCIENCE 2016. [DOI: 10.1080/11956860.1997.11682383] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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Wu Q, Pagès L, Wu J. Relationships between root diameter, root length and root branching along lateral roots in adult, field-grown maize. ANNALS OF BOTANY 2016; 117:379-90. [PMID: 26744490 PMCID: PMC4765541 DOI: 10.1093/aob/mcv185] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/08/2015] [Accepted: 10/23/2015] [Indexed: 05/04/2023]
Abstract
BACKGROUND AND AIMS Root diameter, especially apical diameter, plays an important role in root development and function. The variation in diameter between roots, and along roots, affects root structure and thus the root system's overall foraging performance. However, the effect of diameter variation on root elongation, branching and topological connections has not been examined systematically in a population of high-order roots, nor along the roots, especially for mature plants grown in the field. METHODS A method combining both excavation and analysis was applied to extract and quantify root architectural traits of adult, field-grown maize plants. The relationships between root diameter and other root architectural characteristics are analysed for two maize cultivars. KEY RESULTS The basal diameter of the lateral roots (orders 1-3) was highly variable. Basal diameter was partly determined by the diameter of the bearing segment. Basal diameter defined a potential root length, but the lengths of most roots fell far short of this. This was explained partly by differences in the pattern of diameter change along roots. Diameter tended to decrease along most roots, with the steepness of the gradient of decrease depending on basal diameter. The longest roots were those that maintained (or sometimes increased) their diameters during elongation. The branching density (cm(-1)) of laterals was also determined by the diameter of the bearing segment. However, the location of this bearing segment along the mother root was also involved - intermediate positions were associated with higher densities of laterals. CONCLUSIONS The method used here allows us to obtain very detailed records of the geometry and topology of a complex root system. Basal diameter and the pattern of diameter change along a root were associated with its final length. These relationships are especially useful in simulations of root elongation and branching in source-sink models.
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Affiliation(s)
- Qian Wu
- Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Loïc Pagès
- INRA, UR 1115 PSH, Site Agroparc, 84914 Avignon cedex 9, France and
| | - Jie Wu
- State Key Laboratory of Plant Physiology and Biochemistry, Key Laboratory of Crop Cultivation and Farming System, Center of Crop Chemical Control, College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, China
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Croft SA, Pitchford JW, Hodge A. Fishing for nutrients in heterogeneous landscapes: modelling plant growth trade-offs in monocultures and mixed communities. AOB PLANTS 2015; 7:plv109. [PMID: 26371292 PMCID: PMC4641210 DOI: 10.1093/aobpla/plv109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 08/10/2015] [Indexed: 05/27/2023]
Abstract
The problem of how best to find and exploit essential resources, the quality and locations of which are unknown, is common throughout biology. For plants, the need to grow an efficient root system so as to acquire patchily distributed soil nutrients is typically complicated by competition between plants, and by the costs of maintaining the root system. Simple mechanistic models for root growth can help elucidate these complications, and here we argue that these models can be usefully informed by models initially developed for foraging fish larvae. Both plant and fish need to efficiently search a spatio-temporally variable environment using simple algorithms involving only local information, and both must perform this task against a backdrop of intra- and inter-specific competition and background mortality. Here we develop these parallels by using simple stochastic models describing the growth and efficiency of four contrasting idealized root growth strategies. We show that plants which grow identically in isolation in homogeneous substrates will typically perform very differently when grown in monocultures, in heterogeneous nutrient landscapes and in mixed-species competition. In particular, our simulations show a consistent result that plants which trade-off rapid growth in favour of a more efficient and durable root system perform better, both on average and in terms of the best performing individuals, than more rapidly growing ephemeral root systems. Moreover, when such slower growing but more efficient plants are grown in competition, the overall community productivity can exceed that of the constituent monocultures. These findings help to disentangle many of the context-dependent behaviours seen in the experimental literature, and may form a basis for future studies at the level of complex population dynamics and life history evolution.
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Affiliation(s)
- Simon Antony Croft
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK York Centre for Complex Systems Analysis (YCCSA), The Ron Cooke Hub, University of York, Heslington, York YO10 5GE, UK
| | - Jonathan W Pitchford
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK York Centre for Complex Systems Analysis (YCCSA), The Ron Cooke Hub, University of York, Heslington, York YO10 5GE, UK
| | - Angela Hodge
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
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Kong D, Ma C, Zhang Q, Li L, Chen X, Zeng H, Guo D. Leading dimensions in absorptive root trait variation across 96 subtropical forest species. THE NEW PHYTOLOGIST 2014; 203:863-72. [PMID: 24824672 DOI: 10.1111/nph.12842] [Citation(s) in RCA: 204] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 04/03/2014] [Indexed: 05/03/2023]
Abstract
Absorptive root traits show remarkable cross-species variation, but major root trait dimensions across species have not been defined. We sampled first-order roots and measured 14 root traits for 96 angiosperm woody species from subtropical China, including root diameter, specific root length, stele diameter, cortex thickness, root vessel size and density, mycorrhizal colonization rate, root branching intensity, tissue density, and concentrations of carbon and nitrogen ([N]). Root traits differed in the degree of variation and phylogenetic conservatism, but showed predictable patterns of cross-trait coordination. Root diameter, cortex thickness and stele diameter displayed high variation across species (coefficient of variation (CV)=0.51-0.69), whereas the stele:root diameter ratio and [N] showed low variation (CV<0.32). Root diameter, cortex thickness and stele diameter showed a strong phylogenetic signal across species, whereas root branching traits did not, and these two sets of traits were segregated onto two nearly orthogonal (independent) principal component analysis (PCA) axes. Two major dimensions of root trait variation were found: a diameter-related dimension potentially integrating root construction, maintenance, and persistence with mycorrhizal colonization, and a branching architecture dimension expressing root plastic responses to the environment. These two dimensions may offer a promising path for better understanding root trait economics and root ecological strategies world-wide.
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Affiliation(s)
- Deliang Kong
- The Key Laboratory for Urban Habitat Environmental Science and Technology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
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Jacob A, Hertel D, Leuschner C. Diversity and species identity effects on fine root productivity and turnover in a species-rich temperate broad-leaved forest. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:678-689. [PMID: 32481023 DOI: 10.1071/fp13195] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 01/20/2014] [Indexed: 06/11/2023]
Abstract
We investigated the evidence of belowground overyielding in a species-rich temperate broad-leaved forest with an ingrowth core study in 100 plots containing five common tree species (beech, lime, maple, hornbeam, ash) in mono-specific and 2-species or 3-species combinations. This design allowed separating diversity and species identity effects on root dynamics in a mature forest with long continuity. Fine root productivity was not significantly different between mono-specific and 2- or 3-species plots, whereas fine root turnover was significantly higher in the mixed than the mono-specific plots. Species identity effects on root turnover and root productivity were important. Ash achieved in the mixtures the highest fine root productivity and root turnover of all species; it is an apparent key species in this forest. Evidence in support of a diversity effect on fine root productivity and turnover was weak, however.
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Affiliation(s)
- Andreas Jacob
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
| | - Dietrich Hertel
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
| | - Christoph Leuschner
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
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40
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McCormack ML, Guo D. Impacts of environmental factors on fine root lifespan. FRONTIERS IN PLANT SCIENCE 2014; 5:205. [PMID: 24904605 PMCID: PMC4032987 DOI: 10.3389/fpls.2014.00205] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/28/2014] [Indexed: 05/17/2023]
Abstract
The lifespan of fast-cycling roots is a critical parameter determining a large flux of plant carbon into soil through root turnover and is a biological feature regulating the capacity of a plant to capture soil water and nutrients via root-age-related physiological processes. While the importance of root lifespan to whole-plant and ecosystem processes is increasingly recognized, robust descriptions of this dynamic process and its response to changes in climatic and edaphic factors are lacking. Here we synthesize available information and propose testable hypotheses using conceptual models to describe how changes in temperature, water, nitrogen (N), and phosphorus (P) availability impact fine root lifespan within a species. Each model is based on intrinsic responses including root physiological activity and alteration of carbohydrate allocation at the whole-plant level as well as extrinsic factors including mycorrhizal fungi and pressure from pathogens, herbivores, and other microbes. Simplifying interactions among these factors, we propose three general principles describing fine root responses to complex environmental gradients. First, increases in a factor that strongly constrains plant growth (temperature, water, N, or P) should result in increased fine root lifespan. Second, increases in a factor that exceeds plant demand or tolerance should result in decreased lifespan. Third, as multiple factors interact fine root responses should be determined by the most dominant factor controlling plant growth. Moving forward, field experiments should determine which types of species (e.g., coarse vs. fine rooted, obligate vs. facultative mycotrophs) will express greater plasticity in response to environmental gradients while ecosystem models may begin to incorporate more detailed descriptions of root lifespan and turnover. Together these efforts will improve quantitative understanding of root dynamics and help to identify areas where future research should be focused.
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Affiliation(s)
- M. Luke McCormack
- Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of SciencesBeijing, China
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Herzog C, Steffen J, Graf Pannatier E, Hajdas I, Brunner I. Nine years of irrigation cause vegetation and fine root shifts in a water-limited pine forest. PLoS One 2014; 9:e96321. [PMID: 24802642 PMCID: PMC4011741 DOI: 10.1371/journal.pone.0096321] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/05/2014] [Indexed: 11/19/2022] Open
Abstract
Scots pines (Pinus sylvestris L.) in the inner-Alpine dry valleys of Switzerland have suffered from increased mortality during the past decades, which has been caused by longer and more frequent dry periods. In addition, a proceeding replacement of Scots pines by pubescent oaks (Quercus pubescens Willd.) has been observed. In 2003, an irrigation experiment was performed to track changes by reducing drought pressure on the natural pine forest. After nine years of irrigation, we observed major adaptations in the vegetation and shifts in Scots pine fine root abundance and structure. Irrigation permitted new plant species to assemble and promote canopy closure with a subsequent loss of herb and moss coverage. Fine root dry weight increased under irrigation and fine roots had a tendency to elongate. Structural composition of fine roots remained unaffected by irrigation, expressing preserved proportions of cellulose, lignin and phenolic substances. A shift to a more negative δ13C signal in the fine root C indicates an increased photosynthetic activity in irrigated pine trees. Using radiocarbon (14C) measurement, a reduced mean age of the fine roots in irrigated plots was revealed. The reason for this is either an increase in newly produced fine roots, supported by the increase in fine root biomass, or a reduced lifespan of fine roots which corresponds to an enhanced turnover rate. Overall, the responses belowground to irrigation are less conspicuous than the more rapid adaptations aboveground. Lagged and conservative adaptations of tree roots with decadal lifespans are challenging to detect, hence demanding for long-term surveys. Investigations concerning fine root turnover rate and degradation processes under a changing climate are crucial for a complete understanding of C cycling.
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Affiliation(s)
- Claude Herzog
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
- Swiss Federal Institute of Technology Zürich ETH, Zurich, Switzerland
| | - Jan Steffen
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | | | - Irka Hajdas
- Swiss Federal Institute of Technology Zürich ETH, Zurich, Switzerland
| | - Ivano Brunner
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
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42
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Hu F, Mou PP, Weiner J, Li S. Contrasts between whole-plant and local nutrient levels determine root growth and death in Ailanthus altissima (Simaroubaceae). AMERICAN JOURNAL OF BOTANY 2014; 101:812-819. [PMID: 24812109 DOI: 10.3732/ajb.1400129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY There is an ongoing debate about the importance of whole-plant control vs. local modular mechanisms for root growth. We conducted a split-root experiment with different patch/background levels of nitrogen to examine whether local root growth and death are controlled by local resource levels or at the whole-plant level.• METHODS Three microrhizotrons with 0, 10, and 100 µg N/g growth medium levels (74 g growth medium each) were attached to pots of high or low soil N in which one Ailanthus altissima individual was growing. One fine root was guided into each of the microrhizotrons and photographed every 4 d. Plants were harvested after 28 d; root growth and mortality in the microrhizotrons were recorded. Changes in root length, number of laterals, and interlateral length were determined from the photos and analyzed.• KEY RESULTS While overall plant growth was influenced by background N level, both patch and background N levels influenced root growth and mortality in patches. Local roots proliferated most when the patch N level was high and background level low, and they proliferated least and showed highest mortality when patch N was low and the background level high.• CONCLUSIONS The fate of roots growing in a patch is influenced by the resource environment of the plant's other roots as well as the resource levels in the patch itself. Thus, the growth and death of roots in patches is determined by both modular and whole-plant mechanisms.
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Affiliation(s)
- Fengqin Hu
- The Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China Institute of Soil Science, Chinese Academy of Sciences, No. 71 Beijing East Road, Nanjing 210008, China
| | - Paul P Mou
- The Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China
| | - Jacob Weiner
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Shuo Li
- The Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China
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Noguchi K, Nagakura J, Kaneko S. Biomass and morphology of fine roots of sugi (Cryptomeria japonica) after 3 years of nitrogen fertilization. FRONTIERS IN PLANT SCIENCE 2013; 4:347. [PMID: 24027575 PMCID: PMC3760069 DOI: 10.3389/fpls.2013.00347] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 08/16/2013] [Indexed: 05/25/2023]
Abstract
Increasing nitrogen (N) deposition may affect carbon and nutrient dynamics in forest ecosystems. To better understand the effects of N deposition, we need to improve our knowledge of N effects on fine roots (roots <2 mm in diameter), as they are a key factor in carbon and nutrient dynamics. In this study, we fertilized 1 × 2 m plots in a sugi (Cryptomeria japonica) stand (336 kg ha(-) (1) y(-) (1)) for 3 years and evaluated the responses of the fine roots to high N load. After fertilization, the concentration of NO3-N in the soil of N-fertilized (NF) plots was five-times as large as that in the control plots and the effect was more remarkable in the subsurface soil than in the surface soil. The biomass of fine roots <2 mm in diameter appeared to be greater in the NF plots (88 ± 19 g m(-) (2)) than in the control plots (56 ± 14 g m(-) (2)), but this difference was not statistically significant. In both plots, 76% of the biomass was accounted for by fine roots that were <1 mm in diameter. In the surface soil, the specific root length of fine roots <1 mm in diameter was significantly greater, and the diameter of those fine roots was marginally smaller, in the NF plots than in the control plots. In addition, the concentration of N in fine roots <1 mm in diameter was marginally greater in the NF plots than in the control plots. There may have been increased production of thinner fine roots or increased root branching in the NF plots. This study suggests that, in general, high N load is likely to have positive effects on sugi in terms of fine root characteristics and the effects on fine-root morphology are more evident than the effects on fine-root biomass.
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Affiliation(s)
- Kyotaro Noguchi
- Shikoku Research Center, Forestry and Forest Products Research InstituteKochi, Japan
| | - Junko Nagakura
- Department of Forest Site Environment, Forestry and Forest Products Research InstituteTsukuba, Japan
| | - Shinji Kaneko
- Department of Forest Site Environment, Forestry and Forest Products Research InstituteTsukuba, Japan
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44
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Rytter RM. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis. TREE PHYSIOLOGY 2013; 33:924-39. [PMID: 23963409 DOI: 10.1093/treephys/tpt060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots <1 mm (5-6 year(-1)) and 1-2 mm (0.9-2.8 year(-1)) were not affected by changes in N or water availability. Fine root production (<1 mm) differed between Alnus and Salix, and between treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited < unlimited < N limited. Few treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.
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Affiliation(s)
- Rose-Marie Rytter
- Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden; Present address: Rytter Science, Backavägen 16, S-268 68 Röstånga, Sweden
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45
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Adams TS, McCormack ML, Eissenstat DM. Foraging strategies in trees of different root morphology: the role of root lifespan. TREE PHYSIOLOGY 2013; 33:940-8. [PMID: 24128849 DOI: 10.1093/treephys/tpt067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Resource exploitation of patches is influenced not simply by the rate of root production in the patches but also by the lifespan of the roots inhabiting the patches. We examined the effect of sustained localized nitrogen (N) fertilization on root lifespan in four tree species that varied widely in root morphology and presumed foraging strategy. The study was conducted in a 12-year-old common garden in central Pennsylvania using a combination of data from minirhizotron and root in-growth cores. The two fine-root tree species, Acer negundo L. and Populus tremuloides Michx., exhibited significant increases in root lifespan with local N fertilization; no significant responses were observed in the two coarse-root tree species, Sassafras albidum Nutt. and Liriodendron tulipifera L. Across species, coarse-root tree species had longer median root lifespan than fine-root tree species. Localized N fertilization did not significantly increase the N concentration or the respiration of the roots growing in the N-rich patch. Our results suggest that some plant species appear to regulate the lifespan of different portions of their root system to improve resource acquisition while other species do not. Our results are discussed in the context of different strategies of foraging of nutrient patches in species of different root morphology.
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Affiliation(s)
- Thomas S Adams
- Department of Ecosystem Science and Management and Intercollege Graduate Program in Ecology, Pennsylvania State University, University Park, PA 16802, USA
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46
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Wu Y, Deng Y, Zhang J, Wu J, Tang Y, Cao G, Zhang F, Cui X. Root size and soil environments determine root lifespan: evidence from an alpine meadow on the Tibetan Plateau. Ecol Res 2013. [DOI: 10.1007/s11284-013-1038-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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Verburg PSJ, Young AC, Stevenson BA, Glanzmann I, Arnone JA, Marion GM, Holmes C, Nowak RS. Do increased summer precipitation and N deposition alter fine root dynamics in a Mojave Desert ecosystem? GLOBAL CHANGE BIOLOGY 2013; 19:948-56. [PMID: 23504850 DOI: 10.1111/gcb.12082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 10/17/2012] [Indexed: 05/24/2023]
Abstract
Climate change is expected to impact the amount and distribution of precipitation in the arid southwestern United States. In addition, nitrogen (N) deposition is increasing in these regions due to increased urbanization. Responses of belowground plant activity to increases in soil water content and N have shown inconsistent patterns between biomes. In arid lands, plant productivity is limited by water and N availability so it is expected that changes in these factors will affect fine root dynamics. The objectives of this study were to quantify the effects of increased summer precipitation and N deposition on fine root dynamics in a Mojave Desert ecosystem during a 2-year field experiment using minirhizotron measurements. Root length density, production, and mortality were measured in field plots in the Mojave Desert receiving three 25 mm summer rain events and/or 40 kg N ha(-1) yr(-1) . Increased summer precipitation and N additions did not have an overall significant effect on any of the measured root parameters. However, differences in winter precipitation resulting from interannual variability in rainfall appeared to affect root parameters with root production and turnover increasing following a wet winter most likely due to stimulation of annual grasses. In addition, roots were distributed more deeply in the soil following the wet winter. Root length density was initially higher under canopies compared to canopy interspaces, but converged toward the end of the study. In addition, roots tended to be distributed more deeply into the soil in canopy interspace areas. Results from this study indicated that increased summer precipitation and N deposition in response to climate change and urbanization are not likely to affect fine root dynamics in these Mojave Desert ecosystems, despite studies showing aboveground plant physiological responses to these environmental perturbations. However, changes in the amount and possibly distribution of winter precipitation may affect fine root dynamics.
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Affiliation(s)
- Paul S J Verburg
- Division of Earth and Ecosystem Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA.
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Urcelay C, Acho J, Joffre R. Fungal root symbionts and their relationship with fine root proportion in native plants from the Bolivian Andean highlands above 3,700 m elevation. MYCORRHIZA 2011; 21:323-330. [PMID: 20922435 DOI: 10.1007/s00572-010-0339-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 09/16/2010] [Indexed: 05/11/2023]
Abstract
Here, we examined the colonization by fungal root symbionts in the cultivated Andean grain Chenopodium quinoa and in 12 species that dominate plant communities in the Bolivian Altiplano above 3,700 m elevation and explore for the possible relationships between fungal colonization and fine root proportion. The 12 most abundant species in the study area were consistently colonized by AMF and DSE. In contrast, the annual Andean grain C. quinoa showed negligible or absence of mycorrhizal fungi colonizing roots. On the other hand, C. quinoa, Junelia seriphioides and Chersodoma jodopappa were infected to a varying degree by the root pathogen Olpidium sp. We observed no relationship between AMF and DSE colonization and proportion of fine roots in the root system, but instead, the ratio between DSE and AMF colonization (ratio DSE/AMF) negatively related with proportion of fine roots. Our findings support the hypothesis regarding the importance of DSE at high altitudes and suggest a functional relationship between the rate of DSE/AMF and proportion of fine roots. The colonization by the root pathogen Olpidium sp. in C. quinoa deserves further study since this Andean grain is increasingly important for the local economy in these marginal areas.
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Affiliation(s)
- Carlos Urcelay
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC) and FCEFyN, Universidad Nacional de Córdoba, Casilla de Correo 495, 5000, Córdoba, Argentina.
| | - Julieta Acho
- Herbario Nacional de Bolivia, Instituto de Ecologia, UMSA, La Paz, Bolivia
| | - Richard Joffre
- IRD CEFE CNRS, UMR 5175, 1919 Route de Mende, 34293, Montpellier Cedex 05, France
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Butler AJ, Barbier N, Cermák J, Koller J, Thornily C, McEvoy C, Nicoll B, Perks MP, Grace J, Meir P. Estimates and relationships between aboveground and belowground resource exchange surface areas in a Sitka spruce managed forest. TREE PHYSIOLOGY 2010; 30:705-714. [PMID: 20404352 DOI: 10.1093/treephys/tpq022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Our knowledge of the nature of belowground competition for moisture and nutrients is limited. In this study, we used an earth impedance method to determine the root absorbing area of Sitka spruce (Picea sitchensis (Bong.) Carr.) trees, making measurements in stands of differing density (2-, 4- and 6-m inter-tree spacing). We compared absorbing root area index (RAI(absorbing); based on the impedance measure) with fine root area index (RAI(fine); based on estimates of total surface area of fine roots) and related these results to investment in conductive roots. Root absorbing area was a near-linear function of tree stem diameter at 1.3 m height. At the stand level, RAI(absorbing), which is analogous to and scaled with transpiring leaf area index (maximum stomatal pore area per unit ground area; LAI(transpiring)), increased proportionally with basal area across the three stands. In contrast, RAI(fine) was inversely propotional to basal area. The ratio of RAI(absorbing) to LAI(transpiring) ranged from 7.7 to 17.1, giving an estimate of the relative aboveground versus belowground resource exchange areas. RAI(absorbing) provides a way of characterizing ecosystem functioning as a physiologically meaningful index of belowground absorbing area.
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Affiliation(s)
- A J Butler
- School of Geosciences, University of Edinburgh, Drummond Street, Edinburgh EH89XP, UK.
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50
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Kobe RK, Iyer M, Walters MB. Optimal partitioning theory revisited: Nonstructural carbohydrates dominate root mass responses to nitrogen. Ecology 2010; 91:166-79. [DOI: 10.1890/09-0027.1] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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