TY - JOUR
T1 - Plant coexistence depends on ecosystem nutrient cycles
T2 - Extension of the resource-ratio theory
AU - Daufresne, Tanguy
AU - Hedin, Lars O.
PY - 2005/6/28
Y1 - 2005/6/28
N2 - We present a model of plant-nutrient interactions that extends classical resource competition theory to environments in which essential nutrients (resources) are recycled between plant and soil pools and dissolved nutrients are lost through plant-available (i.e., inorganic forms) or plant-unavailable (i.e., complex organic forms) pathways. Losses by dissolved organic pathways can alter ratios of nutrients that are recycled and supplied within the plant-soil system, thereby influencing competition and coexistence among plant species. In special cases, our extended model does not differ from classical models, but in more realistic cases our model introduces new dynamical behavior that influences competitive outcomes. At equilibrium, coexistence still depends on nutrient supply and consumption, but nutrient supply includes recycling and is highly sensitive to whether a species promotes more organic losses of the nutrient that limits its own growth than of nutrients that limit its competitors. Because recycling operates with a time delay compared with consumption, recycling-mediated effects on competition can, under certain conditions, lead to sustained population oscillations. Our findings have implications for how we understand nutrient competition, nutrient cycles, and plant evolutionary strategies.
AB - We present a model of plant-nutrient interactions that extends classical resource competition theory to environments in which essential nutrients (resources) are recycled between plant and soil pools and dissolved nutrients are lost through plant-available (i.e., inorganic forms) or plant-unavailable (i.e., complex organic forms) pathways. Losses by dissolved organic pathways can alter ratios of nutrients that are recycled and supplied within the plant-soil system, thereby influencing competition and coexistence among plant species. In special cases, our extended model does not differ from classical models, but in more realistic cases our model introduces new dynamical behavior that influences competitive outcomes. At equilibrium, coexistence still depends on nutrient supply and consumption, but nutrient supply includes recycling and is highly sensitive to whether a species promotes more organic losses of the nutrient that limits its own growth than of nutrients that limit its competitors. Because recycling operates with a time delay compared with consumption, recycling-mediated effects on competition can, under certain conditions, lead to sustained population oscillations. Our findings have implications for how we understand nutrient competition, nutrient cycles, and plant evolutionary strategies.
KW - Biogeochemistry nutrient losses evolution
KW - Plant competition recycling
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U2 - 10.1073/pnas.0406427102
DO - 10.1073/pnas.0406427102
M3 - Article
C2 - 15964989
AN - SCOPUS:21544458313
SN - 0027-8424
VL - 102
SP - 9212
EP - 9217
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
ER -