Nutrient cycling drives plant community trait assembly and ecosystem functioning in a tropical mountain biodiversity hotspot

  • Community trait assembly in highly diverse tropical rainforests is still poorly understood. Based on more than a decade of field measurements in a biodiversity hotspot of southern Ecuador, we implemented plant trait variation and improved soil organic matter dynamics in a widely used dynamic vegetation model (the Lund-Potsdam-Jena General Ecosystem Simulator, LPJ-GUESS) to explore the main drivers of community assembly along an elevational gradient. In the model used here (LPJ-GUESS-NTD, where NTD stands for nutrient-trait dynamics), each plant individual can possess different trait combinations, and the community trait composition emerges via ecological sorting. Further model developments include plant growth limitation by phosphorous (P) and mycorrhizal nutrient uptake. The new model version reproduced the main observed community trait shift and related vegetation processes along the elevational gradient, but only if nutrient limitations to plant growth were activated. In turn, when traits were fixed, low productivity communities emerged due to reduced nutrient-use efficiency. Mycorrhizal nutrient uptake, when deactivated, reduced net primary production (NPP) by 61–72% along the gradient. Our results strongly suggest that the elevational temperature gradient drives community assembly and ecosystem functioning indirectly through its effect on soil nutrient dynamics and vegetation traits. This illustrates the importance of considering these processes to yield realistic model predictions.
Author:Mateus Dantas de PaulaORCiDGND, Matthew ForrestORCiD, Liam LanganORCiD, Jörg BendixORCiDGND, Jürgen HomeierORCiDGND, Andre Velescu, Wolfgang WilckeORCiD, Thomas HicklerORCiD
Parent Title (English):The new phytologist
Place of publication:Oxford [u.a.]
Document Type:Article
Date of Publication (online):2021/07/06
Date of first Publication:2021/07/06
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2022/07/11
Tag:dynamic vegetation model; mycorrhiza; nutrient cycling; plant community assembly; plant functional traits; tropical montane forests (TMF)
Page Number:16
First Page:551
Last Page:566
Deutsche Forschungsgemeinschaft. Grant Number: FOR2730
Institutes:Geowissenschaften / Geographie
Fachübergreifende Einrichtungen / Biodiversität und Klima Forschungszentrum (BiK-F)
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell - Keine Bearbeitung 4.0