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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: 101] [Impact Index Per Article: 33.7] [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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Vanden Heuvel J, Centinari M. Under-Vine Vegetation Mitigates the Impacts of Excessive Precipitation in Vineyards. FRONTIERS IN PLANT SCIENCE 2021; 12:713135. [PMID: 34381488 PMCID: PMC8352556 DOI: 10.3389/fpls.2021.713135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Excessive precipitation events have greatly increased in several grape growing regions due to human-caused climate change. These heavy downpours result in a myriad of problems in the vineyard including soil aggregate breakdown, soil runoff, nutrient leaching, excessive vine vegetative growth, and diseased fruit. The negative impacts of excessive precipitation events on vineyards are exacerbated by the maintenance of bare soil under the vines. Exposure of bare soil results in soil erosion and runoff which pollutes nearby watersheds; raindrops weaken and break apart soil aggregates, leading to increased soil erosivity and contributing to the formation of surface crusts. In addition to excessive precipitation events, some grape growing regions can be characterized by fertile soils. The availability of ample water and nutrients can lead to highly vigorous vines with shoot growth continuing through harvest. Long shoots and large leaves result in shaded fruit, a humid vine microclimate, and excessive cluster rot. In this review, we examined how either natural (i.e., resident) or seeded under-vine vegetation (UVV) can help mitigate many of the problems associated with excessive precipitation. Through providing vegetative coverage to reduce the force of raindrops, increasing soil organic matter and enhancing soil microbial diversity, UVV can reduce the soil degradation and off-site impacts caused by excessive precipitation events. Through competition for soil resources, UVV can reduce excessive vegetative growth of vines and decrease cluster rot incidence and severity, although grapevine response to UVV can be highly variable. We discussed recent advances in understanding below and aboveground vine response and acclimation to UVV and presented current evidence of factors influencing the impact of UVV on vine growth and productivity to assist practitioners in making informed decisions and maximize the ecosystem services provided by UVV.
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Affiliation(s)
| | - Michela Centinari
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
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Biotic and Abiotic Determinants of Soil Organic Matter Stock and Fine Root Biomass in Mountain Area Temperate Forests—Examples from Cambisols under European Beech, Norway Spruce, and Silver Fir (Carpathians, Central Europe). FORESTS 2021. [DOI: 10.3390/f12070823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.
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Reingwirtz I, Uretsky J, Cuneo IF, Knipfer T, Reyes C, Walker MA, McElrone AJ. Inherent and Stress-Induced Responses of Fine Root Morphology and Anatomy in Commercial Grapevine Rootstocks with Contrasting Drought Resistance. PLANTS (BASEL, SWITZERLAND) 2021; 10:1121. [PMID: 34205907 PMCID: PMC8227383 DOI: 10.3390/plants10061121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/24/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
Some grapevine rootstocks perform better than others during and after drought events, yet it is not clear how inherent and stress-induced differences in root morphology and anatomy along the length of fine roots are involved in these responses. Using a variety of growing conditions and plant materials, we observed significant differences in root diameter, specific root length (SRL) and root diameter distribution between two commonly used commercial grapevine rootstocks: Richter 110 (110R; drought resistant) and Millardet et de Grasset 101-14 (101-14Mgt; drought sensitive). The 110R consistently showed greater root diameters with smaller SRL and proportion of root length comprised of fine lateral roots. The 110R also exhibited significantly greater distance from tip to nearest lateral, longer white root length, and larger proportion of root length that is white under drought stress. Mapping of fine root cortical lacunae showed similar patterns between the rootstocks; mechanical failure of cortical cells was common in the maturation zone, limited near the root tip, and increased with drought stress for both genotypes; however, lacuna formed under wetter soil conditions in 110R. Results suggest that drought resistance in grapevine rootstocks is associated with thick, limitedly branched roots with a larger proportion of white-functional roots that tend to form lacuna under more mild water deficit, all of which likely favor continued resource acquisition at depth.
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Affiliation(s)
- Idan Reingwirtz
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Jake Uretsky
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Italo F. Cuneo
- Faculty of Agriculture and Food Sciences, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340025, Chile;
| | - Thorsten Knipfer
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
| | - Clarissa Reyes
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - M. Andrew Walker
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Andrew J. McElrone
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
- Crops Pathology and Genetics Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
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徐 丽. Research Progress on Effects of Nitrogen Deposition on Dynamics and Morphology of Forest Fine Roots. INTERNATIONAL JOURNAL OF ECOLOGY 2021. [DOI: 10.12677/ije.2021.104078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pan L, Lie GW, Xue L, Chen HY. Changes of Cinnamomum camphora root characteristics and soil properties under ozone stress in South China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:30684-30692. [PMID: 31049865 DOI: 10.1007/s11356-019-05199-7] [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: 01/17/2018] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
High O3 exposure affects the forest growth and soil characteristics. Although there is substantial evidence that O3 does impose a stress on forest trees, the effects of O3 on roots and soil of evergreen broad-leaved tree species in South China remain unknown. The effects of ozone (O3) fumigation on the root biomass, root morphology, root nutrient, soil physical, and chemical properties were examined in Cinnamomum camphora seedlings grown under four O3 treatments (charcoal-filtered air (CF) or O3 at 1×, 2× and 4× ambient concentration). O3 significantly decreased root biomass and root carbon (C). Regardless of O3 level, elevated O3 significantly resulted in reduced root surface area, volume, number of forks, and specific root length (SRL). The percentages of fine to total root in terms of root surface area and root volume of seedlings under the CF and 1 × O3 treatments were significantly higher than those of seedlings under the 4 × O3 treatment, indicating that high O3 level impaired the growth performance of fine roots. O3 affected root growth and structures, which increased soil bulk density and reduced soil total porosity and void ratio. The soil pH under all O3 fumigation treatments significantly increased compared with CF treatment, whereas the organic matter significantly decreased. In conclusion, although the increased O3 level enhanced root N and P under 2 and 4 × O3 treatments compared with 1 × O3 treatment as compensation mechanisms to prevent O3-induced decrease in root C gain and root functions, O3 still decreased the root biomass and root tips, and changed the soil physical and chemical properties.
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Affiliation(s)
- Lan Pan
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Gan-Wen Lie
- Guangdong Eco-Engineering Polytechnic, Guangzhou, 510520, People's Republic of China
| | - Li Xue
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
| | - Hong-Yue Chen
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, People's Republic of China
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Huo C, Cheng W. Improved root turnover assessment using field scanning rhizotrons with branch order analysis. Ecosphere 2019. [DOI: 10.1002/ecs2.2793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Changfu Huo
- Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China
| | - Weixin Cheng
- Department of Environmental Studies University of California Santa Cruz California 95064 USA
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Krasowski MJ, Lavigne MB, Szuter MA, Olesinski J, Kershaw JA, McGarrigle E. Age-related changes in survival and turnover rates of balsam fir (Abies balsamea (L.) Mill.) fine roots. TREE PHYSIOLOGY 2018; 38:865-876. [PMID: 29452424 DOI: 10.1093/treephys/tpy010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/01/2018] [Indexed: 06/08/2023]
Abstract
Fine-root (≤2 mm) demographics change as forests age, but the direction and extent of change are unknown. Knowledge of the change and understanding of causes will improve predictions of climate change impacts. We used minirhizotrons at three young and three mature balsam fir (Abies balsamea (L.) Mill.) sites to measure median lifespan (MLS) for each site and for annual cohorts. We computed turnover rate from the inverse of MLS (Tinv) and calculated a second turnover rate (T) from annual mortality, annual production and previous year-end standing crop. Median lifespan at mature sites (436 days) was half that at young sites (872 days). Median lifespan of annual cohorts varied widely at all sites. Age-class distributions of fine roots seen by minirhizotrons changed with increasing years of observation, with older age classes accumulating more slowly at mature sites. Our findings highlight the need to determine whether the proportional contributions of absorbing and transporting fine roots to annual production and their median lifespans change during stand development. Due to its variation among annual cohorts, we believe robust estimates of MLS at our sites require 5-7 years of observation, and reliable estimates of Tinv are reached earlier than T.
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Affiliation(s)
- Marek J Krasowski
- Faculty of Forestry and Environmental Management, University of New Brunswick, PO Box 4400, 28 Dineen Drive, Fredericton, NB E3B 5A6, Canada
| | - Michael B Lavigne
- Natural Resources Canada, Canadian Forest Service - Atlantic Forestry Centre, PO Box 4000, Fredericton, NB E3B 5P7, Canada
| | - Michael A Szuter
- Faculty of Forestry and Environmental Management, University of New Brunswick, PO Box 4400, 28 Dineen Drive, Fredericton, NB E3B 5A6, Canada
- Applied Ecological Services, Inc., 80 Franklin St., Dublin, OH 43017, USA
| | - Jakub Olesinski
- Faculty of Forestry and Environmental Management, University of New Brunswick, PO Box 4400, 28 Dineen Drive, Fredericton, NB E3B 5A6, Canada
- Environment and Natural Resources, PO Box 4354, 173 Hay River Dene Reserve, Hay River, NT X0E 0R7, Canada
| | - John A Kershaw
- Faculty of Forestry and Environmental Management, University of New Brunswick, PO Box 4400, 28 Dineen Drive, Fredericton, NB E3B 5A6, Canada
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Mohamed A, Monnier Y, Mao Z, Lobet G, Maeght JL, Ramel M, Stokes A. An evaluation of inexpensive methods for root image acquisition when using rhizotrons. PLANT METHODS 2017; 13:11. [PMID: 28286541 PMCID: PMC5341412 DOI: 10.1186/s13007-017-0160-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 02/22/2017] [Indexed: 05/17/2023]
Abstract
BACKGROUND Belowground processes play an essential role in ecosystem nutrient cycling and the global carbon budget cycle. Quantifying fine root growth is crucial to the understanding of ecosystem structure and function and in predicting how ecosystems respond to climate variability. A better understanding of root system growth is necessary, but choosing the best method of observation is complex, especially in the natural soil environment. Here, we compare five methods of root image acquisition using inexpensive technology that is currently available on the market: flatbed scanner, handheld scanner, manual tracing, a smartphone application scanner and a time-lapse camera. Using the five methods, root elongation rate (RER) was measured for three months, on roots of hybrid walnut (Juglans nigra × Juglans regia L.) in rhizotrons installed in agroforests. RESULTS When all methods were compared together, there were no significant differences in relative cumulative root length. However, the time-lapse camera and the manual tracing method significantly overestimated the relative mean diameter of roots compared to the three scanning methods. The smartphone scanning application was found to perform best overall when considering image quality and ease of use in the field. The automatic time-lapse camera was useful for measuring RER over several months without any human intervention. CONCLUSION Our results show that inexpensive scanning and automated methods provide correct measurements of root elongation and length (but not diameter when using the time-lapse camera). These methods are capable of detecting fine roots to a diameter of 0.1 mm and can therefore be selected by the user depending on the data required.
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Affiliation(s)
- Awaz Mohamed
- AMAP, INRA, CNRS, IRD, Université de Montpellier, Montpellier, France
| | - Yogan Monnier
- AMAP, INRA, CNRS, IRD, Université de Montpellier, Montpellier, France
| | - Zhun Mao
- AMAP, INRA, CNRS, IRD, Université de Montpellier, Montpellier, France
| | - Guillaume Lobet
- Earth and Life Institute, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
- Agrosphere-IBG3, Forschungszentrum Juelich GmbH, 52428 Juelich, Germany
| | - Jean-Luc Maeght
- iEES-Paris (IRD, Sorbonne Universités, UPMC Univ Paris 06, CNRS, INRA, UPEC, Université Paris Diderot), Soils and Fertilizers Research Institute (SFRI), Duc Thang Ward, Bac Tu Liem District, IRD, Hanoi, Vietnam
| | - Merlin Ramel
- AMAP, INRA, CNRS, IRD, Université de Montpellier, Montpellier, France
| | - Alexia Stokes
- AMAP, INRA, CNRS, IRD, Université de Montpellier, Montpellier, France
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Radville L, Bauerle TL, Comas LH, Marchetto KA, Lakso AN, Smart DR, Dunst RM, Eissenstat DM. Limited linkages of aboveground and belowground phenology: A study in grape. AMERICAN JOURNAL OF BOTANY 2016; 103:1897-1911. [PMID: 27879261 DOI: 10.3732/ajb.1600212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/29/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Plant phenology influences resource utilization, carbon fluxes, and interspecific interactions. Although controls on aboveground phenology have been studied to some degree, controls on root phenology are exceptionally poorly understood. METHODS We used minirhizotrons to examine the timing of grape root production over 5 yr in Fredonia, New York, USA, in a humid continental climate; and over 3 yr in Oakville, California, USA, in a Mediterranean climate. We used data from previous experiments to examine the relationship of root phenology with aboveground phenology. We compared interannual variability in root and shoot growth and determined the influence of abiotic factors on the timing of root initiation, peak root standing crop, peak root growth rate, and cessation of root growth. KEY RESULTS Root phenology was not tightly coupled with aboveground phenological periods. Both sites typically had one yearly root flush and high interannual variability in root growth. Root phenology was more variable in California than in New York. In this and other published studies, interannual variation in root phenology was greater than variation in aboveground phenology. The three phenological phases of root growth-root initiation, peak root growth, and root cessation-were related to different suites of abiotic factors. CONCLUSIONS Root phenology is highly variable among years. Analysis of potential controlling factors over several years suggest that belowground phenological phases should be analyzed separately from each other. If aboveground grape phenology responds differently than belowground phenology to changes in air temperature, global warming may further uncouple the timing of aboveground and belowground growth.
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Affiliation(s)
- Laura Radville
- Department of Ecosystem Science and Management and the Ecology Graduate Program, The Pennsylvania State University, State College, Pennsylvania, USA
| | - Taryn L Bauerle
- Department of Ecosystem Science and Management and the Ecology Graduate Program, The Pennsylvania State University, State College, Pennsylvania, USA
- School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Louise H Comas
- Department of Ecosystem Science and Management and the Ecology Graduate Program, The Pennsylvania State University, State College, Pennsylvania, USA
- USDA-ARS Water Management and Systems Research Unit, Fort Collins, Colorado, USA
| | - Katherine A Marchetto
- Department of Ecosystem Science and Management and the Ecology Graduate Program, The Pennsylvania State University, State College, Pennsylvania, USA
| | - Alan N Lakso
- Horticulture Section, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA
| | - David R Smart
- Department of Viticulture and Enology, University of California-Davis, Davis, California, USA
| | - Richard M Dunst
- Horticulture Section, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA
| | - David M Eissenstat
- Department of Ecosystem Science and Management and the Ecology Graduate Program, The Pennsylvania State University, State College, Pennsylvania, USA
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Wang Z, Ding L, Wang J, Zuo X, Yao S, Feng J. Effects of root diameter, branch order, root depth, season and warming on root longevity in an alpine meadow. Ecol Res 2016. [DOI: 10.1007/s11284-016-1385-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Pisciotta A, Fazio G, Barbagallo M, Di Lorenzo R. Alternative nursery propagation for vineyards establishment. ACTA HORTICULTURAE 2016:137-144. [DOI: 10.17660/actahortic.2016.1136.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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13
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Zhang X, Wang W. The decomposition of fine and coarse roots: their global patterns and controlling factors. Sci Rep 2015; 5:9940. [PMID: 25942391 PMCID: PMC4649993 DOI: 10.1038/srep09940] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/16/2015] [Indexed: 11/08/2022] Open
Abstract
Fine root decomposition represents a large carbon (C) cost to plants, and serves as a potential soil C source, as well as a substantial proportion of net primary productivity. Coarse roots differ markedly from fine roots in morphology, nutrient concentrations, functions, and decomposition mechanisms. Still poorly understood is whether a consistent global pattern exists between the decomposition of fine (<2 mm root diameter) and coarse (≥2 mm) roots. A comprehensive terrestrial root decomposition dataset, including 530 observations from 71 sampling sites, was thus used to compare global patterns of decomposition of fine and coarse roots. Fine roots decomposed significantly faster than coarse roots in middle latitude areas, but their decomposition in low latitude regions was not significantly different from that of coarse roots. Coarse root decomposition showed more dependence on climate, especially mean annual temperature (MAT), than did fine roots. Initial litter lignin content was the most important predictor of fine root decomposition, while lignin to nitrogen ratios, MAT, and mean annual precipitation were the most important predictors of coarse root decomposition. Our study emphasizes the necessity of separating fine roots and coarse roots when predicting the response of belowground C release to future climate changes.
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Affiliation(s)
- Xinyue Zhang
- Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
- Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Wei Wang
- Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
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14
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Rodríguez MV, Bertiller MB. Temporal asynchrony in fine-root biomass may contribute to shrub and grass coexistence in mixed patches. AUSTRAL ECOL 2014. [DOI: 10.1111/aec.12110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Mónica Beatriz Bertiller
- Centro Nacional Patagónico (CONICET); Boulevard Brown 2825 9120 Puerto Madryn Chubut Argentina
- Universidad Nacional de la Patagonia San Juan Bosco; Puerto Madryn Chubut Argentina
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15
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Atucha A, Merwin IA, Brown MG, Gardiazabal F, Mena F, Adriazola C, Goebel M, Bauerle T. Root distribution and demography in an avocado (Persea americana) orchard under groundcover management systems. FUNCTIONAL PLANT BIOLOGY : FPB 2013; 40:507-515. [PMID: 32481127 DOI: 10.1071/fp12317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/04/2013] [Indexed: 06/11/2023]
Abstract
The effect of groundcover management systems on root demography and distribution of newly planted avocado (Persea americana Mill) trees was examined using minirhizotron techniques. We evaluated three groundcover systems: (1) bare soil (BS), pre- and post-emergence herbicides; (2) vegetation strip (VS), post-emergence herbicide applied in a 1-m wide strip centred on the tree row plus a groundcover mixture seeded between tree rows; and (3) complete groundcover (GC), covering the entire surface of the plots. Root production was higher in the non-bearing year (2009-10) than in the bearing year (2010-11). Trees in the BS plots had more roots of bigger diameter in the top 30cm of soil and trees in VS and GC plots had more roots in the 30-60cm depth and of smaller diameter. Lifespan of spring-born roots were 61 and 59% greater than those born during autumn and summer, respectively and soil depth and root diameter were positively correlated with root longevity. Lifespan of thinner roots (<0.2mm) in the BS and VS plots were 49 and 33% greater than GC respectively. Avocado trees grown in contrasting condition compared with their native habitat show high morphological root plasticity, in response to resource and non-resource competition when grown in mixed stands.
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Affiliation(s)
- Amaya Atucha
- Department of Horticulture and Landscape Architecture, Western Colorado Research Center, Colorado State University, 3168 B ½ Road, Grand Junction, CO 81503, USA
| | - Ian A Merwin
- Department of Horticulture, Cornell University, 134A Plant Science Building, Ithaca, NY 14853, USA
| | - Michael G Brown
- Department of Horticulture, Cornell University, 134A Plant Science Building, Ithaca, NY 14853, USA
| | | | - Francisco Mena
- Sociedad Gardiazabal and Mena, Blanco 512, Quillota, Chile
| | | | - Marc Goebel
- Department of Horticulture and Intercollege Graduate Program in Ecology, Pennsylvania State University, University Park, PA 16802, USA
| | - Taryn Bauerle
- Department of Horticulture, Cornell University, 134A Plant Science Building, Ithaca, NY 14853, USA
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16
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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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17
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Root Biomass Dynamics Under Experimental Warming and Doubled Precipitation in a Tallgrass Prairie. Ecosystems 2012. [DOI: 10.1007/s10021-012-9525-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Polverigiani S, McCormack ML, Mueller CW, Eissenstat DM. Growth and physiology of olive pioneer and fibrous roots exposed to soil moisture deficits. TREE PHYSIOLOGY 2011; 31:1228-1237. [PMID: 22084020 DOI: 10.1093/treephys/tpr110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In woody plants, pioneer roots are the main roots used to expand the root system horizontally and vertically whereas fibrous 'feeder' roots are chiefly used in the absorption of water and nutrients. Because of their different roles, we expected newly emerged pioneer and fibrous roots to respond differently to restrictions in soil moisture. We hypothesized that fibrous roots would exhibit greater growth plasticity and greater physiological impairment from soil moisture deficits, especially under heterogeneous conditions. We compared the responses of fibrous and pioneer roots of olive seedlings (Olea europaea) to localized and uniform soil moisture deficits in transparent containers in the greenhouse. In comparison with uniformly wet conditions, uniformly dry conditions caused reduced shoot photosynthesis and reduced shoot growth, but no significant effect on root morphology, root respiration (measured in aerated buffer solution using excised roots) or electrolyte leakage as a function of root age. Under heterogeneous soil moisture conditions, root growth tended to preferentially occur in the moist sector, especially in the pioneer roots. In comparison with pioneer roots in the moist sector, pioneer roots in the dry sector had higher tissue density and higher suberin content, but no shift in root respiration, non-structural carbohydrates or electrolyte leakage. In contrast, fibrous roots in the dry sector exhibited evidence of impaired physiology in older (>38 days) roots compared with similar age fibrous roots in the moist sector. While we anticipated that, compared with pioneer roots, fibrous roots would be more sensitive to soil moisture deficits as expressed by higher electrolyte leakage, we did not expect the strong growth plasticity of pioneer roots under heterogeneous soil moisture conditions. Differentiating the responses of these two very different root types can improve our understanding of how different portions of the root system of woody plants cope with soil moisture deficits.
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Affiliation(s)
- S Polverigiani
- Dipartimento SAPROV, Università Politecnica delle Marche, Ancona, Italy
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19
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Ferguson SD, Nowak RS. Transitory effects of elevated atmospheric CO₂ on fine root dynamics in an arid ecosystem do not increase long-term soil carbon input from fine root litter. THE NEW PHYTOLOGIST 2011; 190:953-967. [PMID: 21355868 DOI: 10.1111/j.1469-8137.2011.03654.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Experimental increases in atmospheric CO₂ often increase root production over time, potentially increasing soil carbon (C) sequestration. Effects of elevated atmospheric CO₂ on fine root dynamics in a Mojave desert ecosystem were examined for the last 4.5 yr of a long-term (10-yr) free air CO₂ enrichment (FACE) study at the Nevada desert FACE facility (NDFF). Sets of minirhizotron tubes were installed at the beginning of the NDFF experiment to characterize rooting dynamics of the dominant shrub Larrea tridentata, the codominant shrub Ambrosia dumosa and the plant community as a whole. Although significant treatment effects occurred sporadically for some fine root measurements, differences were transitory and often in opposite directions during other time-periods. Nonetheless, earlier root growth under elevated CO₂ helped sustain increased assimilation and shoot growth. Overall CO₂ treatment effects on fine root standing crop, production, loss, turnover, persistence and depth distribution were not significant for all sampling locations. These results were similar to those that occurred near the beginning of the NDFF experiment but unlike those in other ecosystems. Thus, increased C input into soils is unlikely to occur from fine root litter under elevated atmospheric CO₂ in this arid ecosystem.
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Affiliation(s)
- Scot D Ferguson
- Department of Natural Resources and Environmental Science, MS 370, University of Nevada, Reno, NV 89557, USA
| | - Robert S Nowak
- Department of Natural Resources and Environmental Science, MS 370, University of Nevada, Reno, NV 89557, USA
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20
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Gu J, Yu S, Sun Y, Wang Z, Guo D. Influence of root structure on root survivorship: an analysis of 18 tree species using a minirhizotron method. Ecol Res 2011. [DOI: 10.1007/s11284-011-0833-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Zadworny M, Eissenstat DM. Contrasting the morphology, anatomy and fungal colonization of new pioneer and fibrous roots. THE NEW PHYTOLOGIST 2011; 190:213-221. [PMID: 21210817 DOI: 10.1111/j.1469-8137.2010.03598.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Not all roots born as first-order branches are the same and this has important consequences for overall function. We hypothesized that, compared with fibrous roots, pioneer roots are built to live longer at the expense of absorptive capacity. We tested this hypothesis by investigating pioneer and fibrous roots in their first 14 d of life in the arbuscular mycorrhizal tree species: Acer negundo, Acer saccharum, Juglans nigra, Liriodendron tulipifera and Populus tremuloides. Root observations were made with root-access boxes that allowed roots to be sampled at known ages in field-grown trees. Compared to fibrous roots, pioneer roots had larger diameter, lower specific root length, greater average length and a lack of mycorrhizal or nonmycorrhizal fungal colonization. Pioneer roots < 14 d old had more layers of hypodermis with a lower percentage of putative passage cells and more protoxylem groups than similar age fibrous roots. Our results suggest that pioneer roots are constructed for defense against biotic and abiotic challenges, exploration of soil distal to the stem, high fibrous root branching and secondary development with high axial hydraulic conductivity at the expense of mycorrhizal colonization and high absorptive capacity for water and nutrients.
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Affiliation(s)
- Marcin Zadworny
- Laboratory of Root System Pathology, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
| | - David M Eissenstat
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
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22
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Goebel M, Hobbie SE, Bulaj B, Zadworny M, Archibald DD, Oleksyn J, Reich PB, Eissenstat DM. Decomposition of the finest root branching orders: linking belowground dynamics to fine-root function and structure. ECOL MONOGR 2011. [DOI: 10.1890/09-2390.1] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Kitajima K, Anderson KE, Allen MF. Effect of soil temperature and soil water content on fine root turnover rate in a California mixed conifer ecosystem. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg001210] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Baldi E, Toselli M, Eissenstat DM, Marangoni B. Organic fertilization leads to increased peach root production and lifespan. TREE PHYSIOLOGY 2010; 30:1373-82. [PMID: 20921024 DOI: 10.1093/treephys/tpq078] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We evaluated the effects of mineral and organic fertilizers on peach root dynamics in the growing season from 2003 to 2006 in a nectarine (Prunus persica L.) orchard, planted in 2001 and located in the Po valley, northeastern Italy. Very few studies have conducted long-term investigations of root dynamics of fruit crops. Our main objective was to determine whether organic fertilizers affect root dynamics differently than mineral fertilizers. The experiment was a completely randomized block design with four replicates of three treatments: unfertilized, mineral fertilized and composted with municipal waste. Mineral fertilizers included P (100 kg ha(-1) year(-1)) and K (200 kg ha(-1) year(-1)) applied only at planting and N (70-130 kg ha(-1) year(-1)) split into two applications, one at 40 days after full bloom (60%) and the other in September (40%) each year. The compost fertilization represented a yearly rate of 10 metric tons (t) dry weight ha(-1), which approximates (in kg ha(-1) year(-1)) 240 N, 100 P and 200 K, split similarly to that described for the mineral fertilization of N. Both root growth and survival were evaluated at 20-day intervals during the growing season by the minirhizotron technique. Compost increased the production of new roots compared with the other treatments (P < 0.01). Roots were mainly produced at a depth of 41-80 cm and from March to May and in late summer. An analysis of covariance indicated no significant effect of soil nitrate on root production (P = 0.47). The root lifespan was longer in compost-treated trees than in mineral-fertilized or unfertilized trees (P < 0.01) and it was strongly affected by time of birth; roots born later in the summer lived longer than those born in the spring. Across years and treatments, the average root lifespan was positively correlated with soil nitrate (r = 0.60; P < 0.001). Variation in root lifespan with method of fertilization could be accounted for by variation in soil nitrate concentration as indicated by no effect of fertilizer treatment on root lifespan when soil nitrate was included as a covariate. These results reveal how shifting from mineral to organic fertilizers may shift both soil properties and nutrient availability, leading to changes in both root production and lifespan.
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Affiliation(s)
- E Baldi
- Dipartimento di Colture Arboree, viale Fanin 46, 40127 Bologna, Italy.
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25
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Pritchard SG, Maier CA, Johnsen KH, Grabman AJ, Chalmers AP, Burke MK. Soil incorporation of logging residue affects fine-root and mycorrhizal root-tip dynamics of young loblolly pine clones. TREE PHYSIOLOGY 2010; 30:1299-1310. [PMID: 20668289 DOI: 10.1093/treephys/tpq067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Loblolly pine (Pinus taeda L.) plantations cover a large geographic area of the southeastern USA and supply a large proportion of the nation's wood products. Research on management strategies designed to maximize wood production while also optimizing nutrient use efficiency and soil C sequestration is needed. We used minirhizotrons to quantify the effects of incorporating logging residues into soil on fine-root standing crop, production and mortality, and mycorrhizal root tips in young loblolly pine clones of contrasting ideotypes. Clone 93 is known to allocate more C to stem growth, while clone 32 allocates less C to stems and more to leaves. The relative allocation by these clones to support fine-root turnover is unknown. Clone 32 exhibited 37% more fine-root mortality than clone 93, which was mainly the result of a greater standing crop of fine roots. Fine-root standing crop in plots amended with logging residue was initially higher than control plots, but 2.5 years after planting, standing crop in control plots had exceeded that in mulched plots. Production of mycorrhizal root tips, on the other hand, was initially higher in control than mulched plots, but during the last 9 months of the study, mycorrhizal tip production was greater in mulched than control plots, especially for clone 93. As expected, turnover rate of fine roots was greater in surface soil (0-25 cm) compared with deeper (25-50 cm) soil and for small roots (< 0.4 mm diameter) compared with larger fine roots (0.4-2.0 mm diameter). Rates of fine-root turnover were similar in both clones. Organic matter additions reduced survivorship of individual roots and increased turnover rates of fine-root populations. Results indicate that management decisions should be tailored to fit the growth and allocation patterns of available clones.
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Affiliation(s)
- Seth G Pritchard
- College of Charleston, Department of Biology, Charleston, SC 29401, USA.
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26
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Bai W, Xun F, Li Y, Zhang W, Li L. Rhizome severing increases root lifespan of Leymus chinensis in a typical steppe of Inner Mongolia. PLoS One 2010; 5:e12125. [PMID: 20711343 PMCID: PMC2920826 DOI: 10.1371/journal.pone.0012125] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/16/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Root lifespan is an important trait that determines plants' ability to acquire and conserve soil resources. There have been several studies investigating characteristics of root lifespan of both woody and herbaceous species. However, most of the studies have focused on non-clonal plants, and there have been little data on root lifespan for clonal plants that occur widely in temperate grasslands. METHODOLOGY/PRINCIPAL FINDINGS We investigated the effects of rhizome severing on overall root lifespan of Leymus chinensis, a clonal, dominant grass species in the temperate steppe in northern China, in a 2-year field study using modified rhizotron technique. More specifically, we investigated the effects of rhizome severing on root lifespan of roots born in different seasons and distributed at different soil depths. Rhizome severing led to an increase in the overall root lifespan from 81 to 103 days. The increase in root lifespan exhibited spatial and temporal characteristics such that it increased lifespan for roots distributed in the top two soil layers and for roots born in summer and spring, but it had no effect on lifespan of roots in the deep soil layer and born in autumn. We also examined the effect of rhizome severing on carbohydrate and N contents in roots, and found that root carbohydrate and N contents were not affected by rhizome severing. Further, we found that root lifespan of Stipa krylovii and Artemisia frigida, two dominant, non-clonal species in the temperate steppe, was significantly longer (118 d) than that of L. chinensis (81 d), and this value became comparable to that of L. chinensis under rhizome severing (103 d). CONCLUSIONS/SIGNIFICANCE We found that root lifespan in dominant, clonal L. chinensis was shorter than for the dominant, non-clonal species of S. krylovii and A. frigida. There was a substantial increase in the root lifespan of L. chinensis in response to severing their rhizomes, and this increase in root lifespan exhibited temporal and spatial characteristics. These findings suggest that the presence of rhizomes is likely to account for the observed short lifespan of clonal plant species in the temperate steppe.
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Affiliation(s)
- Wenming Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fen Xun
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Science, Yuquanlu, Beijing, China
| | - Yang Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Science, Yuquanlu, Beijing, China
| | - Wenhao Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Linghao Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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27
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Fine root decomposition rates do not mirror those of leaf litter among temperate tree species. Oecologia 2009; 162:505-13. [DOI: 10.1007/s00442-009-1479-6] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 10/02/2009] [Indexed: 10/20/2022]
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28
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Espeleta JF, West JB, Donovan LA. Tree species fine-root demography parallels habitat specialization across a sandhill soil resource gradient. Ecology 2009; 90:1773-87. [PMID: 19694127 DOI: 10.1890/08-0056.1] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Single species can substantially alter belowground processes in ecosystems via differential root production and death. However, information on species differences in fine-root demography is virtually absent for natural communities. In this field study, we recorded species-specific fine-root (<2 mm in diameter) demography in adults of four tree species (Pinus palustris, Quercus laevis, Q. incana, and Q. margaretta) that are distributed differentially along soil resource gradients in the fall-line sandhills of the southeastern United States. At a subxeric habitat where all four species co-occur, roots of individual trees of each species were isolated in rhizotrons and tracked individually for three years. Quercus species had similar fine-root morphology but differed substantially for fine-root demography and architecture. Quercus laevis and Q. incana, the species from xeric habitats, showed lower fine-root production, death, percentage mortality, turnover rates, and risk of death, and greater life span and mean root segment length (MRSL) than Q. margaretta, the species from subxeric habitats. Fine roots of P. palustris (a generalist) showed high production and intermediate mortality, turnover rate, longevity, and MRSL. Fine-root survival increased with root order (first to fourth in centripetal order), but the degree of change was species specific. Q. margaretta showed greater increases in survival with order, but all species had similar demography of third- and fourth-order roots. Mycorrhizal roots had greater longevity than non-mycorrhizal roots only in Q. laevis. Species differences were also seasonal. Although these Quercus species are leaf deciduous, some growth of fine roots occurred in Q. margaretta during the "leaf-dormant" season. In our narrow-scale species comparison, species differences in ecological distribution were consistent with the observed variation in fine-root demography and architecture with greater resolution than leaf characters or other root traits such as morphology. Our results also show that narrow-scale variation in fine-root demography (including intra-generic differences) can be as large as broad-scale variation across biomes and vegetation types. Hence, small shifts in community composition have the potential to produce substantial changes below ground.
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Affiliation(s)
- Javier F Espeleta
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA.
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29
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Volder A, Anderson LJ, Smart DR, Bloom AJ, Lakso AN, Eissenstat DM. Estimating nitrogen uptake of individual roots in container- and field-grown plants using a 15N-depletion approach. FUNCTIONAL PLANT BIOLOGY : FPB 2009; 36:621-628. [PMID: 32688675 DOI: 10.1071/fp08330] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Accepted: 05/06/2009] [Indexed: 06/11/2023]
Abstract
We only have a limited understanding of the nutrient uptake physiology of individual roots as they age. Despite this shortcoming, the importance of nutrient uptake processes to our understanding of plant nutrition and nutrient cycling cannot be underestimated. In this study, we used a 15N depletion method that allowed for the measurement of nitrate-N uptake rates on intact, individual, fine roots of known age. We expected that N uptake would decline rapidly as fine roots aged, regardless of the environmental conditions and species used. We compared age dependent uptake patterns of young grape cuttings with those of mature vines and with those of tomato. Although patterns of declining uptake with increasing root age were similar for all species and conditions tested, large differences in maximum N uptake rates existed between young cuttings and mature vines, and between woody and herbaceous species. Maximum rates were 10-fold higher for tomato and 3-fold higher for the grape cuttings, when compared with uptake rates of fine roots of mature vines. Coefficients of variation ranged from 43 to 122% within root age groups. The large variability in physiological characteristics of fine roots of the same age, diameter and order suggests that there is a functional diversity within fine roots that is still poorly understood.
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Affiliation(s)
- Astrid Volder
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
| | - Laurel J Anderson
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
| | - David R Smart
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - Arnold J Bloom
- Department of Plant Science, University of California, Davis, CA 95616, USA
| | - Alan N Lakso
- Department of Horticultural Sciences, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - David M Eissenstat
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
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30
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Elevated CO2 and O3 effects on fine-root survivorship in ponderosa pine mesocosms. Oecologia 2009; 160:827-37. [DOI: 10.1007/s00442-009-1339-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
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31
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Thomson JL, Copes WE. Modeling disease progression of Camellia twig blight using a recurrent event model. PHYTOPATHOLOGY 2009; 99:378-384. [PMID: 19271979 DOI: 10.1094/phyto-99-4-0378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
To improve control of camellia twig blight (CTB) using sanitation methods, a more complete epidemiologic understanding of this disease is necessary. Three CTB disease stages were modeled using recurrent event analysis. Wound inoculated stems were observed at regular intervals for appearance of disease symptoms. Survival times (time from inoculation until symptom appearance) for the three disease stages (mild, moderate, and severe) were regressed against stem diameter, monthly mean hours/day within a specified temperature range (15 to 30 degrees C), and season (spring, summer, fall, and winter). For all three CTB disease stages, stem diameter had a protective effect on survival times, while monthly mean hours/day in the specified temperature range and warmer seasons were risk factors. Based upon median ratios, the mild disease stage developed 2 to 3 times faster in spring, summer, and fall than in winter. Similarly, moderate and severe disease stages developed 2 to 2.5 times faster. For all three disease stages, seasonal differences in stage development were smaller among fall, spring, and summer, varying from 1 to 1.6 times faster. Recurrent event modeling of CTB progression provides knowledge concerning developmental expression of this disease, information necessary for creating a comprehensive, integrated disease management program.
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Affiliation(s)
- J L Thomson
- Southern Regional Research Center, U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS), Baton Rouge, LA 70808, USA.
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32
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Valenzuela-Estrada LR, Vera-Caraballo V, Ruth LE, Eissenstat DM. Root anatomy, morphology, and longevity among root orders in Vaccinium corymbosum (Ericaceae). AMERICAN JOURNAL OF BOTANY 2008; 95:1506-14. [PMID: 21628158 DOI: 10.3732/ajb.0800092] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Understanding root processes at the whole-plant or ecosystem scales requires an accounting of the range of functions within a root system. Studying root traits based on their branching order can be a powerful approach to understanding this complex system. The current study examined the highly branched root system of the ericoid plant, Vaccinium corymbosum L. (highbush blueberry) by classifying its root orders with a modified version of the morphometric approach similar to that used in hydrology for stream classification. Root anatomy provided valuable insight into variation in root function across orders. The more permanent portion of the root system occurred in 4th- and higher-order roots. Roots in these orders had radial growth; the lowest specific root length, N:C ratios, and mycorrhizal colonization; the highest tissue density and vessel number; and the coarsest root diameter. The ephemeral portion of the root system was mainly in the first three root orders. First- and 2nd-order roots were nearly anatomically identical, with similar mycorrhizal colonization and diameter, and also, despite being extremely fine, median lifespans were not very short (115-120 d; estimated with minirhizotrons). Our research underscores the value of examining root traits by root order and its implications to understanding belowground processes.
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Affiliation(s)
- Luis R Valenzuela-Estrada
- Department of Horticulture, The Pennsylvania State University, University Park, Pennsylvania 16802 USA
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Estimation of fine root production, mortality and turnover with Minirhizotron in Larix gmelinii and Fraxinus mandshurica plantations. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11515-008-0084-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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34
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Bai WM, Wang ZW, Chen QS, Zhang WH, Li LH. Spatial and temporal effects of nitrogen addition on root life span ofLeymus chinensisin a typical steppe of Inner Mongolia. Funct Ecol 2008. [DOI: 10.1111/j.1365-2435.2008.01403.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Variation in longevity and traits of leaves among co-occurring understorey plants in a tropical montane forest. JOURNAL OF TROPICAL ECOLOGY 2008. [DOI: 10.1017/s0266467407004725] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:The relationship between leaf longevity and other leaf traits was compared among different life-form categories (trees, herbs, climbers and epiphytes) of 101 plant species in a tropical montane forest on Mt. Halimun, West Java, Indonesia. We applied the Cox proportional hazards regression to estimate the leaf longevity of each species from 30 mo of census data. We examined whether estimated longevity was explained by either species life-form categories, taxonomic groupings (eudicots, monocots, magnoliids and chloranthales, and ferns) or such leaf traits as leaf area, leaf mass per area (LMA), mass-based leaf nitrogen, penetrometer reading, condensed-tannin-free total phenolics and condensed tannin. There was a wide-ranged interspecific variation in leaf longevity, mostly 10–50 mo, similarly across life-form categories. LMA showed a strong positive influence on leaf longevity. We found that relationships between leaf longevity and some leaf traits were different among various life forms. Trees tended to have high LMA, while climbers tended to have low LMA at the same leaf longevity. We hypothesize that such difference among life forms reflects shoot architecture characteristics. Multi-shoot trees with branching architecture need to have self-supporting leaves, whereas semi-epiphytic climbers can maintain relatively low biomass investment to leaves hanging or relying upon the mechanical support from host plants.
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Bauerle TL, Richards JH, Smart DR, Eissenstat DM. Importance of internal hydraulic redistribution for prolonging the lifespan of roots in dry soil. PLANT, CELL & ENVIRONMENT 2008; 31:177-86. [PMID: 18028280 DOI: 10.1111/j.1365-3040.2007.01749.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Redistribution of water within plants could mitigate drought stress of roots in zones of low soil moisture. Plant internal redistribution of water from regions of high soil moisture to roots in dry soil occurs during periods of low evaporative demand. Using minirhizotrons, we observed similar lifespans of roots in wet and dry soil for the grapevine 'Merlot' (Vitis vinifera) on the rootstock 101-14 Millardet de Gramanet (Vitis riparia x Vitis rupestris) in a Napa County, California vineyard. We hypothesized that hydraulic redistribution would prevent an appreciable reduction in root water potential and would contribute to prolonged root survivorship in dry soil zones. In a greenhouse study that tested this hypothesis, grapevine root systems were divided using split pots and were grown for 6 months. With thermocouple psychrometers, we measured water potentials of roots of the same plant in both wet and dry soil under three treatments: control (C), 24 h light + supplemental water (LW) and 24 h light only (L). Similar to the field results, roots in the dry side of split pots had similar survivorship as roots in the wet side of the split pots (P = 0.136) in the C treatment. In contrast, reduced root survivorship was directly associated with plants in which hydraulic redistribution was experimentally reduced by 24 h light. Dry-side roots of plants in the LW treatment lived half as long as the roots in the wet soil despite being provided with supplemental water (P < 0.0004). Additionally, pre-dawn water potentials of roots in dry soil under 24 h of illumination (L and LW) exhibited values nearly twice as negative as those of C plants (P = 0.034). Estimates of root membrane integrity using electrolyte leakage were consistent with patterns of root survivorship. Plants in which nocturnal hydraulic redistribution was reduced exhibited more than twice the amount of electrolyte leakage in dry roots compared to those in wet soil of the same plant. Our study demonstrates that besides a number of ecological advantages to protecting tissues against desiccation, internal hydraulic redistribution of water is a mechanism consistent with extended root survivorship in dry soils.
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Affiliation(s)
- T L Bauerle
- Department of Horticulture, The Pennsylvania State University, University Park, PA 16802, USA
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37
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38
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Seasonal dynamics of fine root biomass, root length density, specific root length, and soil resource availability in a Larix gmelinii plantation. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/s11515-006-0039-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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39
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Withington JM, Reich PB, Oleksyn J, Eissenstat DM. COMPARISONS OF STRUCTURE AND LIFE SPAN IN ROOTS AND LEAVES AMONG TEMPERATE TREES. ECOL MONOGR 2006. [DOI: 10.1890/0012-9615(2006)076[0381:cosals]2.0.co;2] [Citation(s) in RCA: 318] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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40
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Huang X, Lakso AN, Eissenstat DM. Interactive effects of soil temperature and moisture on Concord grape root respiration. JOURNAL OF EXPERIMENTAL BOTANY 2005; 56:2651-60. [PMID: 16143721 DOI: 10.1093/jxb/eri258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Root respiration has important implications for understanding plant growth as well as terrestrial carbon flux with a changing climate. Although soil temperature and soil moisture often interact, rarely have these interactions on root respiration been studied. This report is on the individual and combined effects of soil moisture and temperature on respiratory responses of single branch roots of 1-year-old Concord grape (Vitis labruscana Bailey) vines grown in a greenhouse. Under moist soil conditions, root respiration increased exponentially to short-term (1 h) increases in temperature between 10 degrees C and 33 degrees C. Negligible increases in root respiration occurred between 33 degrees C and 38 degrees C. By contrast to a slowly decreasing Q10 from short-term temperature increases, when roots were exposed to constant temperatures for 3 d, the respiratory Q10 between 10 degrees C and 30 degrees C diminished steeply with an increase in temperature. Above 30 degrees C, respiration declined with an increase in temperature. Membrane leakage was 89-98% higher and nitrogen concentration was about 18% lower for roots exposed to 35 degrees C for 3 d than for those exposed to 25 degrees C and 15 degrees C. There was a strong interaction of respiration with a combination of elevated temperature and soil drying. At low soil temperatures (10 degrees C), respiration was little influenced by soil drying, while at moderate to high temperatures (20 degrees C and 30 degrees C), respiration exhibited rapid declines with decreases in soil moisture. Roots exposed to drying soil also exhibited increased membrane leakage and reduced N. These findings of acclimation of root respiration are important to modelling respiration under different moisture and temperature regimes.
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Affiliation(s)
- Xuming Huang
- Department of Horticulture, Pennsylvania State University, University Park, PA 16802, USA
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Comas LH, Anderson LJ, Dunst RM, Lakso AN, Eissenstat DM. Canopy and environmental control of root dynamics in a long-term study of Concord grape. THE NEW PHYTOLOGIST 2005; 167:829-40. [PMID: 16101919 DOI: 10.1111/j.1469-8137.2005.01456.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Below-ground carbon allocation represents a substantial fraction of net photosynthesis in plants, yet timing of below-ground allocation and endogenous and exogenous factors controlling it are poorly understood. Minirhizotron techniques were used to examine root populations of Vitis labruscana Bailey cv. Concord under two levels of dormant-season canopy removal and irrigation. Root production, pigmentation, death and disappearance to a depth of 110 cm were determined over two wet and two dry years (1997-2000). There was continual root production and senescence, with peak root production rates occurring by midseason. Later in the season, when reproductive demands for carbon were highest and physical conditions limiting, few roots were produced, especially in dry years in nonirrigated vines. Root production under minimal canopy pruning was generally greater and occurred several weeks earlier than root production under heavy pruning, corresponding to earlier canopy development. Initial root production occurred in shallow soils, likely due to temperatures at shallow depths being warmer early in the season. Our study showed intricate relationships between internal carbon demands and environmental conditions regulating root allocation.
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Affiliation(s)
- L H Comas
- Department of Horticulture, Pennsylvania State University, University Park, PA 16802, USA.
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Tjoelker MG, Craine JM, Wedin D, Reich PB, Tilman D. Linking leaf and root trait syndromes among 39 grassland and savannah species. THE NEW PHYTOLOGIST 2005; 167:493-508. [PMID: 15998401 DOI: 10.1111/j.1469-8137.2005.01428.x] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Here, we tested hypothesized relationships among leaf and fine root traits of grass, forb, legume, and woody plant species of a savannah community. CO2 exchange rates, structural traits, chemistry, and longevity were measured in tissues of 39 species grown in long-term monocultures. Across species, respiration rates of leaves and fine roots exhibited a common regression relationship with tissue nitrogen (N) concentration, although legumes had lower rates at comparable N concentrations. Respiration rates and N concentration declined with increasing longevity of leaves and roots. Species rankings of leaf and fine-root N and longevity were correlated, but not specific leaf area and specific root length. The C3 and C4 grasses had lower N concentrations than forbs and legumes, but higher photosynthesis rates across a similar range of leaf N. Despite contrasting photosynthetic pathways and N2-fixing ability among these species, concordance in above- and below-ground traits was evident in comparable rankings in leaf and root longevity, N and respiration rates, which is evidence of a common leaf and root trait syndrome linking traits to effects on plant and ecosystem processes.
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Affiliation(s)
- M G Tjoelker
- Department of Forest Science, Texas A & M University, 2135 TAMU, College Station, TX, 77843-2135, USA.
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Volder A, Smart DR, Bloom AJ, Eissenstat DM. Rapid decline in nitrate uptake and respiration with age in fine lateral roots of grape: implications for root efficiency and competitive effectiveness. THE NEW PHYTOLOGIST 2005; 165:493-501. [PMID: 15720660 DOI: 10.1111/j.1469-8137.2004.01222.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Changes in function as an individual root ages has important implications for understanding resource acquisition, competitive ability and optimal lifespan. Both nitrate uptake and respiration rates of differently aged fine roots of grape (Vitis rupestris x V. riparia cv. 3309 C) were measured. The resulting data were then used to simulate nitrate uptake efficiency and nutrient depletion as a function of root age. Both nitrate uptake and root respiration declined remarkably quickly with increasing root age. The decline in both N uptake and root respiration corresponded with a strong decline in root N concentration, suggesting translocation of nitrogen out of the roots. For simulations where no nutrient depletion occurs at the root surface, daily uptake efficiency was maximal at root birth and lifetime nitrate uptake efficiency slowly increased as the roots aged. Simulations of growth of roots into unoccupied soil using a solute transport model indicated the advantage of high uptake capacity in new roots under competitive conditions where nitrate availability is very transitory.
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Affiliation(s)
- Astrid Volder
- The Pennsylvania State University, Department of Horticulture, University Park, PA, USA.
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Peek MS, Leffler AJ, Ivans CY, Ryel RJ, Caldwell MM. Fine root distribution and persistence under field conditions of three co-occurring Great Basin species of different life form. THE NEW PHYTOLOGIST 2005; 165:171-80. [PMID: 15720631 DOI: 10.1111/j.1469-8137.2004.01186.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Fine roots of an annual grass, a perennial grass and a perennial shrub were examined. Based on life histories and tissue composition, we expected the greatest root persistence for the shrub and shortest for the annual grass. Roots were observed with minirhizotrons over 2 yr for number, length and diameter changes. A Cox proportional hazard regression correlated root persistence with soil water, depth, diameter and date of production. In 2001, grass roots had similar persistence times, but shrub roots had the shortest. In 2002, the annual had the longest median root persistence, the perennial grass intermediate and the perennial shrub had the shortest. All species responded similarly to the magnitude of seasonal precipitation; root numbers increased with favorable soil moisture and disappeared with drying; fewer, thinner roots at greater soil depths were found in the drier year (2001). Root persistence increased with soil moisture, diameter and earlier appearance in the spring. Plasticity in root morphology and placement was influenced by water availability, yet persistence was surprisingly contrary to expectations.
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Affiliation(s)
- Michael S Peek
- Department of Forest, Range and Wildlife Sciences and the Ecology Center, Utah State University, Logan, UT 84322 USA.
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Affiliation(s)
- Kurt S Pregitzer
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA (tel +1 906 4872396; fax +1 906 4872915; email )
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