Neglecting plant–microbe symbioses leads to underestimation of modeled climate impacts

摘要: Abstract. The extent to which terrestrial ecosystems slow climate change by sequestering carbon hinges in part on nutrient limitation. We used a coupled carbon–climate model that accounts for the cost plants of supporting nitrogen-acquiring microbial symbionts explore how nitrogen limitation affects global climate. To do this, we first calculated the reduction net primary production due of nitrogen acquisition. then estimate impacts the resulting increase atmospheric CO2 temperature and precipitation regimes. costs supporting symbiotic nitrogen uptake reduced by 8.1 Pg C yr −1 , with the largest absolute effects occurring tropical forest biomes and largest relative changes boreal alpine biomes. Globally, our model predicted relatively small of nitrogen acquisition increasing 0.1  ∘ C decreasing 6 mm yr . However, there were strong regional impacts, largest impact alpine ecosystems, where such estimated by 1.0  precipitation 9 mm yr As such, results suggest expenditures support microbial symbionts have critical consequences Earth's climate, that carbon–climate models omit these processes will overpredict land carbon sink underpredict change.