EarthShape Chile

Connecting the green and the grey world – an experimental approach to separating climate, vegetation and geochemical effects on nutrient cycling along a climate gradient

01/01/2016 to 31/12/2018

The objective of our project is to combine plant ecological with biogeochemical expertise and methodology for investigating how the relative importance of geochemical and biological processes for geo-biosphere feedbacks change in response to climatic conditions. Therefore, we combine a space-for-time approach with mechanistically orientated field experiments that directly manipulate environmental conditions along the EarthShape climatic gradient in Chile.
With our approach, we aim to address the following overarching questions: Can space substitute for time, and which temporal processes can be better described by a space-for-time approach than others? What is the role of biotic processes in determining the predictability of bio-geo dynamics? Under which circumstances can spatial climate gradients, i.e. the result of long-term climatic impact on the earth surface, serve as proxy for short- to medium term temporal climatic changes? As a side effect, our study will be the first in Chile to investigate the impact of concurrent climate change on ecosystem processes by means of large-scale field experiments.
We adopt a novel experimental approach to address the question whether and to what extent space can really substitute for time. We furthermore study how the relationship between plants, soil and parent rock is mediated by climatic variables.
We will manipulate climate indirectly by reciprocally transplanting plants, soil and litter along the climatic gradient, i.e. we will move subsets of the site-specific systems to a different climate and compare ecosystem processes to control transplants that were done within the same site. On the hillslope scale, we will manipulate climatic conditions indirectly by performing reciprocal transplants of plants and soil between two opposing slopes. Finally, mechanistic information about bio-geo feedback with climate will be generated by implementing permanent rainout shelters at two dryland sites.