TY - JOUR
T1 - Nutrient and water availability alter belowground patterns of biomass allocation, carbon partitioning, and ectomycorrhizal abundance in Betula nigra
AU - Kleczewski, Nathan M.
AU - Herms, Daniel A.
AU - Bonello, Pierluigi
N1 - Funding Information:
Acknowledgments We thank Victoria Caceres and two anonymous reviewers for insightful comments on earlier drafts of this work, and David Snodgrass, Duan Wang, Justin Whitehill and Jim Vent for their assistance with many technical aspects of this work. This research was supported by USDA Forest Service National Urban and Community Forestry Advisory Grant No. 03-DG-11244225-428 to D.A.H. and P.B., a Tree Research and Education Endowment Fund John Z. Duling Grant to P.B. and D.A.H., an Ohio Agricultural Research and Development Center SEEDS Graduate Student Grant to N.M.K., and by State and Federal funds appropriated to the Ohio Agricultural Research and Development Center, The Ohio State University.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/4
Y1 - 2012/4
N2 - In managed settings, seedlings are often fertilized with the objective of enhancing establishment, growth, and survival. However, responses of seedlings to fertilization can increase their susceptibility to abiotic stresses such as drought. Seedlings acclimate to variation in soil resources by reallocating carbon among different physiological processes and compartments, such as above versus belowground growth, secondary metabolism, and support of ectomycorrhizal fungi (EMF). We examined the effects of nutrient and water availability on carbon allocation to above and belowground growth of river birch (Betula nigra), as well as partitioning among root sugars, starch, phenolics, lignin, and EMF abundance. As nutrient availability increased, total plant biomass and total leaf area increased, while percent root biomass decreased. Root sugars, total root phenolics and EMF abundance responded quadratically to nutrient availability, being lowest at intermediate fertility levels. Decreased water availability reduced total leaf area and root phenolics relative to well-watered controls. No interactions between nutrient and water availability treatments were detected, which may have been due to the moderate degree of drought stress imposed in the low water treatment. Our results indicate that nutrient and water availability significantly alter patterns of carbon allocation and partitioning in roots of Betula nigra seedlings. The potential effects of these responses on stress tolerance are discussed.
AB - In managed settings, seedlings are often fertilized with the objective of enhancing establishment, growth, and survival. However, responses of seedlings to fertilization can increase their susceptibility to abiotic stresses such as drought. Seedlings acclimate to variation in soil resources by reallocating carbon among different physiological processes and compartments, such as above versus belowground growth, secondary metabolism, and support of ectomycorrhizal fungi (EMF). We examined the effects of nutrient and water availability on carbon allocation to above and belowground growth of river birch (Betula nigra), as well as partitioning among root sugars, starch, phenolics, lignin, and EMF abundance. As nutrient availability increased, total plant biomass and total leaf area increased, while percent root biomass decreased. Root sugars, total root phenolics and EMF abundance responded quadratically to nutrient availability, being lowest at intermediate fertility levels. Decreased water availability reduced total leaf area and root phenolics relative to well-watered controls. No interactions between nutrient and water availability treatments were detected, which may have been due to the moderate degree of drought stress imposed in the low water treatment. Our results indicate that nutrient and water availability significantly alter patterns of carbon allocation and partitioning in roots of Betula nigra seedlings. The potential effects of these responses on stress tolerance are discussed.
KW - Acclimation
KW - Growth-differentiation balance hypothesis
KW - Optimal allocation theory
KW - Phenotypic plasticity
KW - Root:shoot ratio
KW - Secondary metabolism
KW - Stress tolerance
KW - Water stress
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U2 - 10.1007/s00468-011-0613-3
DO - 10.1007/s00468-011-0613-3
M3 - Article
AN - SCOPUS:84858286842
VL - 26
SP - 525
EP - 533
JO - Trees - Structure and Function
JF - Trees - Structure and Function
SN - 0931-1890
IS - 2
ER -