A research framework for projecting ecosystem change in highly diverse tropical mountain ecosystems

Jörg Bendix,Juan P Suarez,Jürgen Homeier,Lutz Breuer,Mateus Dantas De Paula,Katja Trachte,Christoph Leuschner,Thomas Hickler,Eike L Neuschulz,Roland Brandl,Matthias Schleuning,Nicolay Aguire,Wolfgang Wilcke,David Windhorst,Nina Farwig,Diego Inclan,Achim Bräuning,Katrin Böhning-Gaese,Erwin Beck

doi:10.1007/s00442-021-04852-8

Abstract

Tropical mountain ecosystems are threatened by climate and land-use changes. Their diversity and complexity make projections how they respond to environmental changes challenging. A suitable way are trait-based approaches, by distinguishing between response traits that determine the resistance of species to environmental changes and effect traits that are relevant for species' interactions, biotic processes, and ecosystem functions. The combination of those approaches with land surface models (LSM) linking the functional community composition to ecosystem functions provides new ways to project the response of ecosystems to environmental changes. With the interdisciplinary project RESPECT, we propose a research framework that uses a trait-based response-effect-framework (REF) to quantify relationships between abiotic conditions, the diversity of functional traits in communities, and associated biotic processes, informing a biodiversity-LSM. We apply the framework to a megadiverse tropical mountain forest. We use a plot design along an elevation and a land-use gradient to collect data on abiotic drivers, functional traits, and biotic processes. We integrate these data to build the biodiversity-LSM and illustrate how to test the model. REF results show that aboveground biomass production is not directly related to changing climatic conditions, but indirectly through associated changes in functional traits. Herbivory is directly related to changing abiotic conditions. The biodiversity-LSM informed by local functional trait and soil data improved the simulation of biomass production substantially. We conclude that local data, also derived from previous projects (platform Ecuador), are key elements of the research framework. We specify essential datasets to apply this framework to other mountain ecosystems.

Highlights

Tropical mountains are biodiversity hotspots (Myers et al 2000)
We used community-weighted mean (CMW) trait values of specific leaf area (SLA) to analyze their importance for the ecosystem function biomass production (Fig. 6a) as well as trait values (SLA) of the above-mentioned individual trees of 52 species within plots to unveil their importance for the biotic process herbivory (Fig. 6b)
We propose that integrating detailed data on functional trait diversity and biotic processes of complex ecosystems into statistical and land surface models (LSM) modeling approaches will advance understanding of the functional importance of biodiversity and projections of the consequences of global change for highly diverse mountain ecosystems

Summary

Introduction

Tropical mountains are biodiversity hotspots (Myers et al 2000). At the same time, mountain ecosystems are vulnerable to environmental changes (Elsen and Tingley 2015).

Materials and methods

Results and conclusion

Conclusion