The role of megafauna in biogeochemical cycles and greenhouse gas fluxes: implications for climate and ecosystems throughout history

Descripción del proyecto

Un estudio más detallado de las interacciones entre la megafauna y los ecosistemas

Los grandes animales —la megafauna— tienen un gran impacto en el funcionamiento de los ecosistemas y el clima, ya que mediante el consumo y la excreción de biomasa aceleran el ciclo de los nutrientes, aumentan la productividad vegetal e influyen en los flujos edáficos de gases de efecto invernadero. La megafauna también emite metano al digerir las plantas a través de la fermentación. En el proyecto MegaBiCycle, financiado con fondos europeos, se estudiará esta cuestión a través de las interacciones entre la megafauna y los ecosistemas en un modelo dinámico de la vegetación a escala mundial. La investigación mejorará la comprensión sobre el vínculo entre el clima, la bioesfera y la megafauna. Los hallazgos serán útiles para la política y la conservación.

Objetivo

Megafauna play an important role in carbon cycling and fluxes of greenhouse gases. Through consumption and excretion of biomass, megafauna accelerate nutrient cycling, increasing plant productivity and influencing soil greenhouse gas fluxes. Megafauna also emit methane when digesting plants through fermentation. Consequently, megafauna can have wide-ranging impacts on ecosystem functioning and climate. However, methodological limitations in dynamic global vegetation models and research gaps in megafauna ecology hamper our ability to assess these impacts. These gaps include: (i) a limited representation of megafauna in vegetation models; (ii) a lack of large-scale, long-term studies detailing the influence of megafauna on nutrient cycling and greenhouse gas fluxes; (iii) insufficient knowledge on how the current loss and introduction of megafauna is affecting ecosystems and their services. This project will address these research gaps by first developing a new classification of the effects of megafauna across biomes for present and late Quaternary species. This classification will then be used to simulate megafauna-ecosystem interactions in a dynamic global vegetation model (ORCHIDEE). This new tool will allow to test hypothesis on the effect of past and present changes in megafauna populations on a) plant primary productivity and carbon cycling and b) methane and nitrous oxide fluxes. The proposed project has the potential to greatly advance our understanding of the connection between climate, biosphere, and megafauna. The results will have implication for climate policy and conservation. Strong contributions to climate modelling, ecology, and paleoecology are to be expected. The candidate’s experience in megafauna-ecosystem interactions and ecological modelling, coupled with the host's expertise in climate and vegetation model will provide new insights into the role of megafauna in past, present, and near future global changes in climate and ecosystems.