TY - JOUR
T1 - Drivers of habitat partitioning among three Quercus species along a hydrologic gradient
AU - Teshera-Levye, Jennifer
AU - Miles, Brianna
AU - Terwilliger, Valery
AU - Lovelock, Catherine E.
AU - Cavender-Bares, Jeannine
N1 - Publisher Copyright:
© 2019 The Author(s). All rights reserved.
PY - 2020/2/17
Y1 - 2020/2/17
N2 - A critical process that allows multiple, similar species to coexist in an ecological community is their ability to partition local habitat gradients. The mechanisms that underlie this separation at local scales may include niche differences associated with their biogeographic history, differences in ecological function associated with the degree of shared ancestry and trait-based performance differences, which may be related to spatial or temporal variation in habitat. In this study we measured traits related to water-use, growth and stress tolerance in mature trees and seedlings of three oak species (Quercus alba L., Quercus falcata Michx. and Quercus palustris Münchh). which co-occur in temperate forests across the eastern USA but tend to be found in contrasting hydrologic environments. The three species showed significant differences in their local distributions along a hydrologic gradient. We tested three possible mechanisms that influence their contrasting local environmental distributions and promote their long-term co-existence: (i) differences in their climatic distributions across a broad geographic range, (ii) differences in functional traits related to water use, drought tolerance and growth and (iii) contrasting responses to temporal variation in water availability. We identified key differences between the species in both their range-wide climatic distributions (especially aridity index and mean annual temperature) and physiological traits in mature trees and seedlings, including daily water loss, hydraulic conductance, stress responses, growth rate and biomass allocation. Taken together, these differences explain the habitat partitioning that allows three closely related species to co-occur locally.
AB - A critical process that allows multiple, similar species to coexist in an ecological community is their ability to partition local habitat gradients. The mechanisms that underlie this separation at local scales may include niche differences associated with their biogeographic history, differences in ecological function associated with the degree of shared ancestry and trait-based performance differences, which may be related to spatial or temporal variation in habitat. In this study we measured traits related to water-use, growth and stress tolerance in mature trees and seedlings of three oak species (Quercus alba L., Quercus falcata Michx. and Quercus palustris Münchh). which co-occur in temperate forests across the eastern USA but tend to be found in contrasting hydrologic environments. The three species showed significant differences in their local distributions along a hydrologic gradient. We tested three possible mechanisms that influence their contrasting local environmental distributions and promote their long-term co-existence: (i) differences in their climatic distributions across a broad geographic range, (ii) differences in functional traits related to water use, drought tolerance and growth and (iii) contrasting responses to temporal variation in water availability. We identified key differences between the species in both their range-wide climatic distributions (especially aridity index and mean annual temperature) and physiological traits in mature trees and seedlings, including daily water loss, hydraulic conductance, stress responses, growth rate and biomass allocation. Taken together, these differences explain the habitat partitioning that allows three closely related species to co-occur locally.
KW - coexistance
KW - drought stress
KW - niche partitioning
KW - sapflow
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U2 - 10.1093/treephys/tpz112
DO - 10.1093/treephys/tpz112
M3 - Article
C2 - 31860720
AN - SCOPUS:85081068957
SN - 0829-318X
VL - 40
SP - 142
EP - 157
JO - Tree physiology
JF - Tree physiology
IS - 2
ER -