Adaptive differences in plant physiology and ecosystem paradoxes: insights from metabolic scaling theory

摘要: The link between variation in species-specific plant traits, larger scale patterns of productivity, and other ecosystem processes is an important focus for global change research. Understanding such linkages requires synthesis evolutionary, biogeograpahic, biogeochemical approaches to ecological Recent observations reveal several apparently paradoxical across ecosystems. When compared with warmer low latitudes, ecosystems from cold northerly latitudes are described by (1) a greater temperature normalized instantaneous flux CO2 energy; (2) similar annual values gross primary production (GPP), possibly net production. Recently, authors attributed constancy GPP historical abiotic factors. Here, we show that metabolic scaling theory can be used provide alternative ‘biotically driven’ hypothesis. model provides baseline understanding how potentially adaptive size traits associated metabolism biomass differing biomes influence whole-ecosystem processes. implication one cannot extrapolate leaf/lab/forest level functional responses the globe without considering evolutionary geographic metabolism. We test key this ‐ directional changes stoichiometric autotrophs may mediate growth broad gradients. In support our model, on average, mass-corrected whole-plant rates not related differences growing season or latitude. Further, these autotrophic physiology nutrient content gradients have implications understanding: (i) origin behavior; (ii) potential efficiency carbon dynamics as measured quotient system capacities respiration, R, assimilation, A; (iii) ‘ecosystem constants’ attributes systems do vary (and thus latitude). Together, results highlight critical importance community ecology evolutionary/ physiological role biosphere within integrated earth system.