1
|
Han L, Nan G, He X, Wang J, Zhao J, Zhang X. Soil moisture and soil organic carbon coupled effects in apple orchards on the Loess Plateau, China. Sci Rep 2024; 14:12281. [PMID: 38811638 PMCID: PMC11136960 DOI: 10.1038/s41598-024-63039-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024] Open
Abstract
A large number of economic forests, especially apple orchards (AOs) in the Loess Plateau region of China, have been planted to develop the local economy and increase the income of farmers. The two main constraints preventing AOs on the Loess Plateau from developing sustainably and producing a high and steady yield are soil moisture content (SMC) and soil organic carbon (SOC). Nevertheless, little is currently known about the contributions of roots to these changes in the soil profile and the temporal modes of the SMC-SOC coupled effects. In our research, we analyzed the dynamic changes in SMC and SOC in AOs of various years in northern Shaanxi Province, as well as the coupled relationship between the two, and attempted to describe the function of roots in these changes. Research have shown: (1) As the age of the AOs increased, the SMC continued to decline throughout the 0-500 cm profile, especially at depths of 100-500 cm. SMC depletion mainly occurred in AOs aged 20 years (30.02%/year) and 30 years (31.18%/year). (2) Compared with abandoned land (AL), all the AOs except for the 6-year-old AO showed a carbon sequestration effect, and the carbon sequestration effect increased with age. The carbon sequestration rate of the 12-year-old AO was the highest and then decreased with age. Both surface and deeper soils showed better carbon sequestration, with a large amount of SOC being sequestered in deeper soil layers (> 100 cm). (3) The coupled effects of SMC and SOC varied with age and depth. The SMC in the deeper layers was significantly negatively correlated with SOC. Root dry weight density (RDWD) was significantly negatively correlated with SMC and significantly positively correlated with SOC. Path analysis suggested that SMC directly affects SOC at different soil depths, and regulates SOC by affecting RDWD, but these effects are significantly different at different depths. Therefore, we propose that management of AO should focus on the moisture deficit and carbon sequestration capabilities of deeper soils to ensure the sustainability of water use in AOs and the stability of agricultural carbon sequestration on the Loess Plateau.
Collapse
Affiliation(s)
- Lei Han
- School of Life Sciences, Yan'an University, Yan'an, 716000, China
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China
| | - Guowei Nan
- School of Life Sciences, Yan'an University, Yan'an, 716000, China.
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China.
| | - Xinyu He
- School of Life Sciences, Yan'an University, Yan'an, 716000, China
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China
| | - Jinghui Wang
- School of Life Sciences, Yan'an University, Yan'an, 716000, China
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China
| | - Jirong Zhao
- School of Life Sciences, Yan'an University, Yan'an, 716000, China
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China
| | - Xiangqian Zhang
- School of Life Sciences, Yan'an University, Yan'an, 716000, China
- Engineering Research Center of Microbial Resources Development and Green Recycling, University of Shaanxi Province, Yan'an, 716000, Shaanxi, China
| |
Collapse
|
2
|
Nakahata R. Time-varying response of fine root growth to soil temperature and soil moisture in cypress and deciduous oak forests. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2022; 3:60-73. [PMID: 37284007 PMCID: PMC10168066 DOI: 10.1002/pei3.10072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/06/2022] [Accepted: 02/14/2022] [Indexed: 06/08/2023]
Abstract
Fine root phenology is controlled by complex mechanisms associated with aboveground phenological events and environmental conditions, and therefore, elucidating fine root responses to changing environments remains difficult without considering the dynamics within and among years. This study evaluated the response of fine root growth at variable time scales to the surrounding environments of soil temperature and moisture at ecosystem scales. Optical scanners were used to measure fine root production over 4 years in two forests dominated by either cypress or deciduous oak trees. Correlations between fine root production and soil temperature and moisture were analyzed using the state-space model. Fine root phenology varied among years in the cypress stand and showed stable growth patterns in the oak stand as production peaked in spring every year. Soil temperature had a dominant influence on fine root production, while soil moisture enhanced fine root growth especially in the oak stand. Fine root responses to both soil temperature and moisture peaked during the early growing season, indicating its own temperature hysteresis that means different responses under same temperature within a year. The time-varying response of fine root growth to external factors is a key perspective to explain fine root growth mechanisms, and whether evergreen or deciduous habits differentiates the fine root phenology due to a linkage between above- and belowground resource dynamics.
Collapse
Affiliation(s)
- Ryo Nakahata
- Center for Ecological ResearchKyoto UniversityKyotoJapan
- Graduate School of AgricultureKyoto UniversityKyotoJapan
| |
Collapse
|
3
|
Wang P, Huang K, Hu S. Distinct fine-root responses to precipitation changes in herbaceous and woody plants: a meta-analysis. THE NEW PHYTOLOGIST 2020; 225:1491-1499. [PMID: 31610024 DOI: 10.1111/nph.16266] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Precipitation is one of the most important factors that determine productivity of terrestrial ecosystems. Precipitation across the globe is predicted to change more intensively under future climate change scenarios, but the resulting impact on plant roots remains unclear. Based on 154 observations from experiments in which precipitation was manipulated in the field and root biomass was measured, we investigated responses in fine-root biomass of herbaceous and woody plants to alterations in precipitation. We found that root biomass of herbaceous and woody plants responded differently to precipitation change. In particular, precipitation increase consistently enhanced fine-root biomass of woody plants but had variable effects on herb roots in arid and semi-arid ecosystems. In contrast, precipitation decrease reduced root biomass of herbaceous plants but not woody plants. In addition, with precipitation alteration, the magnitude of root responses was greater in dry areas than in wet areas. Together, these results indicate that herbaceous and woody plants have different rooting strategies to cope with altered precipitation regimes, particularly in water-limited ecosystems. These findings suggest that root responses to precipitation change may critically influence root productivity and soil carbon dynamics under future climate change scenarios.
Collapse
Affiliation(s)
- Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Kailing Huang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Shuijin Hu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
4
|
Mackay DS, Savoy PR, Grossiord C, Tai X, Pleban JR, Wang DR, McDowell NG, Adams HD, Sperry JS. Conifers depend on established roots during drought: results from a coupled model of carbon allocation and hydraulics. THE NEW PHYTOLOGIST 2020; 225:679-692. [PMID: 31276231 DOI: 10.1111/nph.16043] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/01/2019] [Indexed: 06/09/2023]
Abstract
Trees may survive prolonged droughts by shifting water uptake to reliable water sources, but it is unknown if the dominant mechanism involves activating existing roots or growing new roots during drought, or some combination of the two. To gain mechanistic insights on this unknown, a dynamic root-hydraulic modeling framework was developed that set up a feedback between hydraulic controls over carbon allocation and the role of root growth on soil-plant hydraulics. The new model was tested using a 5 yr drought/heat field experiment on an established piñon-juniper stand with root access to bedrock groundwater. Owing to the high carbon cost per unit root area, modeled trees initialized without adequate bedrock groundwater access experienced potentially lethal declines in water potential, while all of the experimental trees maintained nonlethal water potentials. Simulated trees were unable to grow roots rapidly enough to mediate the hydraulic stress, particularly during warm droughts. Alternatively, modeled trees initiated with root access to bedrock groundwater matched the hydraulics of the experimental trees by increasing their water uptake from bedrock groundwater when soil layers dried out. Therefore, the modeling framework identified a critical mechanism for drought response that required trees to shift water uptake among existing roots rather than growing new roots.
Collapse
Affiliation(s)
- D Scott Mackay
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Philip R Savoy
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Charlotte Grossiord
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Xiaonan Tai
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Jonathan R Pleban
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | - Diane R Wang
- Department of Geography, University at Buffalo, Buffalo, NY, 14261, USA
| | | | - Henry D Adams
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK, 74078, USA
| | - John S Sperry
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| |
Collapse
|
5
|
Phillips ML, McNellis BE, Allen MF, Allen EB. Differences in root phenology and water depletion by an invasive grass explains persistence in a Mediterranean ecosystem. AMERICAN JOURNAL OF BOTANY 2019; 106:1210-1218. [PMID: 31502242 DOI: 10.1002/ajb2.1344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 07/15/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Flexible phenological responses of invasive plants under climate change may increase their ability to establish and persist. A key aspect of plant phenology is the timing of root production, how it coincides with canopy development and subsequent water-use. The timing of these events within species and across communities could influence the invasion process. We examined above- and belowground phenology of two species in southern California, the native shrub, Adenostoma fasciculatum, and the invasive perennial grass, Ehrharta calycina to investigate relative differences in phenology and water use. METHODS We used normalized difference vegetation index (NDVI) to track whole-canopy activity across the landscape and sap flux sensors on individual chaparral shrubs to assess differences in aboveground phenology of both species. To determine differences in belowground activity, we used soil moisture sensors, minirhizotron imagery, and stable isotopes. RESULTS The invasive grass depleted soil moisture earlier in the spring and produced longer roots at multiple depths earlier in the growing season than the native shrub. However, Adenostoma fasciculatum produced longer roots in the top 10 cm of soil profile in May. Aboveground activity of the two species peaked at the same time. CONCLUSIONS The fact that Ehrharta calycina possessed longer roots earlier in the season suggests that invasive plants may gain a competitive edge over native plants through early activity, while also depleting soil moisture earlier in the season. Depletion of soil moisture earlier by E. calycina suggests that invasive grasses could accelerate the onset of the summer drought in chaparral systems, assuring their persistence following invasion.
Collapse
Affiliation(s)
- Michala L Phillips
- Department of Botany and Plant Sciences, University of California Riverside, 900 University Ave., Riverside, California, 92521, USA
| | - Brandon E McNellis
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, Idaho, 83844, USA
| | - Michael F Allen
- Department of Microbiology and Plant Pathology, University of California Riverside, 900 University Ave., Riverside, California, 92521, USA
| | - Edith B Allen
- Department of Botany and Plant Sciences, University of California Riverside, 900 University Ave., Riverside, California, 92521, USA
| |
Collapse
|
6
|
Li L, Zheng Z, Biederman JA, Xu C, Xu Z, Che R, Wang Y, Cui X, Hao Y. Ecological responses to heavy rainfall depend on seasonal timing and multi-year recurrence. THE NEW PHYTOLOGIST 2019; 223:647-660. [PMID: 30934122 DOI: 10.1111/nph.15832] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
Heavy rainfall events are expected to increase in frequency and severity in the future. However, their effects on natural ecosystems are largely unknown, in particular with different seasonal timing of the events and recurrence over multiple years. We conducted a 4 yr manipulative experiment to explore grassland response to heavy rainfall imposed in either the middle of, or late in, the growing season in Inner Mongolia, China. We measured hierarchical responses at individual, community and ecosystem levels. Surprisingly, above-ground biomass remained stable in the face of heavy rainfall, regardless of seasonal timing, whereas heavy rainfall late in the growing season had consistent negative impacts on below-ground and total biomass. However, such negative biomass effects were not significant for heavy rainfall in the middle of the growing season. By contrast, heavy rainfall in the middle of the growing season had greater positive effects on ecosystem CO2 exchanges, mainly reflected in the latter 2 yr of the 4 yr experiment. This two-stage response of CO2 fluxes was regulated by increased community-level leaf area and leaf-level photosynthesis and interannual variability of natural precipitation. Overall, our study demonstrates that ecosystem impacts of heavy rainfall events crucially depend on the seasonal timing and multiannual recurrence. Plant physiological and morphological adjustment appeared to improve the capacity of the ecosystem to respond positively to heavy rainfall.
Collapse
Affiliation(s)
- Linfeng Li
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Qld, 4111, Australia
| | - Zhenzhen Zheng
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Joel A Biederman
- Southwest Watershed Research Center, Agricultural Research Service, Tucson, AZ, 85719, USA
| | - Cong Xu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhihong Xu
- Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Qld, 4111, Australia
| | - Rongxiao Che
- Institude of International Rivers and Eco-security, Yunnan University, Kunming, Yunnan, 650091, China
| | - Yanfen Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Xiaoyong Cui
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Yanbin Hao
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| |
Collapse
|
7
|
Swanson AC, Schwendenmann L, Allen MF, Aronson EL, Artavia‐León A, Dierick D, Fernandez‐Bou AS, Harmon TC, Murillo‐Cruz C, Oberbauer SF, Pinto‐Tomás AA, Rundel PW, Zelikova TJ. Welcome to the
Atta
world: A framework for understanding the effects of leaf‐cutter ants on ecosystem functions. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13319] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amanda C. Swanson
- Department of Microbiology and Plant Pathology, Center for Conservation Biology University of California Riverside Riverside California
| | | | - Michael F. Allen
- Department of Microbiology and Plant Pathology, Center for Conservation Biology University of California Riverside Riverside California
| | - Emma L. Aronson
- Department of Microbiology and Plant Pathology, Center for Conservation Biology University of California Riverside Riverside California
| | - Allan Artavia‐León
- Center for Research in Cellular and Molecular Biology University of Costa Rica San José Costa Rica
| | - Diego Dierick
- Department of Biological Sciences Florida International University Miami Florida
| | - Angel S. Fernandez‐Bou
- School of Engineering and Environmental Systems Program University of California Merced Merced California
| | - Thomas C. Harmon
- School of Engineering and Environmental Systems Program University of California Merced Merced California
| | - Catalina Murillo‐Cruz
- Center for Research in Cellular and Molecular Biology University of Costa Rica San José Costa Rica
- Center for Research in Microscopic Structures, Biochemistry Department University of Costa Rica San José Costa Rica
| | - Steven F. Oberbauer
- Department of Biological Sciences Florida International University Miami Florida
| | - Adrián A. Pinto‐Tomás
- Center for Research in Cellular and Molecular Biology University of Costa Rica San José Costa Rica
- Center for Research in Microscopic Structures, Biochemistry Department University of Costa Rica San José Costa Rica
- Biochemistry Department, School of Medicine University of Costa Rica San José Costa Rica
| | - Philip W. Rundel
- Department of Ecology and Evolutionary Biology University of California Los Angeles Los Angeles California
| | | |
Collapse
|
8
|
Wang Y, Kim JH, Mao Z, Ramel M, Pailler F, Perez J, Rey H, Tron S, Jourdan C, Stokes A. Tree root dynamics in montane and sub-alpine mixed forest patches. ANNALS OF BOTANY 2018; 122:861-872. [PMID: 29506133 PMCID: PMC6215049 DOI: 10.1093/aob/mcy021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND AIMS The structure of heterogeneous forests has consequences for their biophysical environment. Variations in the local climate significantly affect tree physiological processes. We hypothesize that forest structure also alters tree root elongation and longevity through temporal and spatial variations in soil temperature and water potential. METHODS We installed rhizotrons in paired vegetation communities of closed forest (tree islands) and open patches (canopy gaps), along a soil temperature gradient (elevations of 1400, 1700 and 2000 m) in a heterogeneous mixed forest. We measured the number of growing tree roots, elongation and mortality every month over 4 years. KEY RESULTS The results showed that the mean daily root elongation rate (RER) was not correlated with soil water potential but was significantly and positively correlated with soil temperature between 0 and 8 °C only. The RER peaked in spring, and a smaller peak was usually observed in the autumn. Root longevity was dependent on altitude and the season in which roots were initiated, and root diameter was a significant factor explaining much of the variability observed. The finest roots usually grew faster and had a higher risk of mortality in gaps than in closed forest. At 2000 m, the finest roots had a higher risk of mortality compared with the lower altitudes. CONCLUSIONS The RER was largely driven by soil temperature and was lower in cold soils. At the treeline, ephemeral fine roots were more numerous, probably in order to compensate for the shorter growing season. Differences in soil climate and root dynamics between gaps and closed forest were marked at 1400 and 1700 m, but not at 2000 m, where canopy cover was more sparse. Therefore, heterogeneous forest structure and situation play a significant role in determining root demography in temperate, montane forests, mostly through impacts on soil temperature.
Collapse
Affiliation(s)
- Y Wang
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - J H Kim
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
- Max Planck Institute of Biogeochemistry, Jena, Germany
| | - Z Mao
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - M Ramel
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - F Pailler
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - J Perez
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - H Rey
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| | - S Tron
- ÖGUT, Austrian Society for Environment and Technology, Vienna, Austria
| | - C Jourdan
- CIRAD, UMR Eco&Sols – Ecologie Fonctionnelle & Biogéochimie des Sols & Agroécosystèmes (Montpellier SupAgro-CIRAD-INRA-IRD), Montpellier, France
| | - A Stokes
- University Montpellier, INRA, CNRS, IRD, CIRAD, AMAP, Montpellier, France
| |
Collapse
|
9
|
|
10
|
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: 37] [Impact Index Per Article: 3.7] [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.
Collapse
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
| | | |
Collapse
|
11
|
Pacioni G, Leonardi M, Di Carlo P, Ranalli D, Zinni A, De Laurentiis G. Instrumental monitoring of the birth and development of truffles in a Tuber melanosporum orchard. MYCORRHIZA 2014; 24 Suppl 1:S65-S72. [PMID: 24522842 DOI: 10.1007/s00572-014-0561-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/20/2014] [Indexed: 06/03/2023]
Abstract
Mycorrhizal symbiotic plants, soil suitability, temperature, and humidity are, by general consensus, considered decisive factors in truffle production. However, experimental approaches to define the environmental conditions that stimulate formation of truffle primordia and promote their growth to maturity have been lacking. By analysis of data of many atmospheric and soil parameters collected since 2009 within a Tuber melanosporum orchard, the trends of metabolic activity, detected as CO2 production in the soil, have been identified as the most reliable parameter to indicate the 'birth' of the truffle primordia. They seem to be produced when mycelial activity is intense and undergoes water stress, after which it resumes. About 6-18 days after recovery of metabolic activity, we could collect primordia of T. melanosporum. Many die or develop too early and consequently rot or are eaten by insect larvae. These events occur several times during summer and autumn, those that 'sprout' in late summer or later grow steadily and reach maturity. Using a particular ground-penetrating radar (GPR) setup to discriminate truffles, we could identify individual truffles in the soil after they have enlarged to at least 6 mm in diameter and follow their growth in volume and diameter over time. These two instrumental methods (CO2 sensor and GPR), although yet to be improved, open new important perspectives to better understand truffle biology and manage truffle orchards to support the newly acquired demonstration of the fundamental role of host plants for the nutrient transfer to the ectomycorrhiza-mycelium-fruiting body complex of T. melanosporum.
Collapse
Affiliation(s)
- G Pacioni
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Via Vetoio snc loc. Coppito, I-67100, L'Aquila, Italy,
| | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Hernandez RR, Allen MF. Diurnal patterns of productivity of arbuscular mycorrhizal fungi revealed with the Soil Ecosystem Observatory. THE NEW PHYTOLOGIST 2013; 200:547-557. [PMID: 23844990 PMCID: PMC4288973 DOI: 10.1111/nph.12393] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 05/24/2013] [Indexed: 05/08/2023]
Abstract
Arbuscular mycorrhizal (AM) fungi are the most abundant plant symbiont and a major pathway of carbon sequestration in soils. However, their basic biology, including their activity throughout a 24-h day : night cycle, remains unknown. We employed the in situ Soil Ecosystem Observatory to quantify the rates of diurnal growth, dieback and net productivity of extra-radical AM fungi. AM fungal hyphae showed significantly different rates of growth and dieback over a period of 24 h and paralleled the circadian-driven photosynthetic oscillations observed in plants. The greatest rates (and incidences) of growth and dieback occurred between noon and 18:00 h. Growth and dieback events often occurred simultaneously and were tightly coupled with soil temperature and moisture, suggesting a rapid acclimation of the external phase of AM fungi to the immediate environment. Changes in the environmental conditions and variability of the mycorrhizosphere may alter the diurnal patterns of productivity of AM fungi, thereby modifying soil carbon sequestration, nutrient cycling and host plant success.
Collapse
Affiliation(s)
- Rebecca R Hernandez
- Department of Environmental Earth System Science, Stanford University, Stanford, CA, 94305, USA
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Center for Conservation Biology, University of California, Riverside, CA, 92521, USA
| | - Michael F Allen
- Center for Conservation Biology, University of California, Riverside, CA, 92521, USA
- Department of Biology, University of California, Riverside, CA, 92521, USA
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA, 92521, USA
| |
Collapse
|
14
|
Allen MF, Kitajima K. In situ high-frequency observations of mycorrhizas. THE NEW PHYTOLOGIST 2013; 200:222-228. [PMID: 23772913 DOI: 10.1111/nph.12363] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
Understanding the temporal variation of soil and root dynamics is a major step towards determining net carbon in ecosystems. We describe the installation and structure of an in situ soil observatory and sensing network consisting of an automated minirhizotron with associated soil and atmospheric sensors. Ectomycorrhizal hyphae were digitized daily during 2011 in a Mediterranean climate, high-elevation coniferous forest. Hyphal length was high, but stable during winter in moist and cold soil. As soil began to warm and dry, simultaneous mortality and production indicating turnover followed precipitation events. Mortality continued through the dry season, although some hyphae persisted through the extremes. With autumn monsoons, rapid hyphal re-growth occurred following each event. Relative hyphal length is dependent upon soil temperature and moisture. Soil respiration is related to the daily change in hyphal production, but not hyphal mortality. Continuous sensor and observation systems can provide more accurate assessments of soil carbon dynamics.
Collapse
Affiliation(s)
- Michael F Allen
- Center for Conservation Biology, University of California, Riverside, CA, 92521-0334, USA
| | - Kuni Kitajima
- Center for Conservation Biology, University of California, Riverside, CA, 92521-0334, USA
| |
Collapse
|
15
|
Plaut JA, Yepez EA, Hill J, Pangle R, Sperry JS, Pockman WT, McDowell NG. Hydraulic limits preceding mortality in a piñon-juniper woodland under experimental drought. PLANT, CELL & ENVIRONMENT 2012; 35:1601-1617. [PMID: 22462824 DOI: 10.1111/j.1365-3040.2012.02512.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Drought-related tree mortality occurs globally and may increase in the future, but we lack sufficient mechanistic understanding to accurately predict it. Here we present the first field assessment of the physiological mechanisms leading to mortality in an ecosystem-scale rainfall manipulation of a piñon-juniper (Pinus edulis-Juniperus monosperma) woodland. We measured transpiration (E) and modelled the transpiration rate initiating hydraulic failure (E(crit) ). We predicted that isohydric piñon would experience mortality after prolonged periods of severely limited gas exchange as required to avoid hydraulic failure; anisohydric juniper would also avoid hydraulic failure, but sustain gas exchange due to its greater cavitation resistance. After 1 year of treatment, 67% of droughted mature piñon died with concomitant infestation by bark beetles (Ips confusus) and bluestain fungus (Ophiostoma spp.); no mortality occurred in juniper or in control piñon. As predicted, both species avoided hydraulic failure, but safety margins from E(crit) were much smaller in piñon, especially droughted piñon, which also experienced chronically low hydraulic conductance. The defining characteristic of trees that died was a 7 month period of near-zero gas exchange, versus 2 months for surviving piñon. Hydraulic limits to gas exchange, not hydraulic failure per se, promoted drought-related mortality in piñon pine.
Collapse
Affiliation(s)
- Jennifer A Plaut
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
| | | | | | | | | | | | | |
Collapse
|