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FERT-WARMNational ProjectsDec 2016 to Dec 2019

Saturation of carbon sinks: from a CO2 and N fertilization-dominated period to a warming-dominated period

The terrestrial biosphere is currently acting as a sink for about a quarter of the total anthropogenic CO2 emissions. But this capacity is slowing down its increase in the last years. This project aims to investigate how these warming, drought, and nutrient limitations and imbalances affect the C sink capacity of Earth terrestrial biosphere. We expect to reach a very substantial advance in the knowledge of the likely change from a fertilization dominated period to a warming dominated period in terrestrial biosphere and of the impacts of such shift on terrestrial biosphere.

Introduction

The terrestrial biosphere is currently acting as a sink for about a quarter of the total anthropogenic CO2 emissions. But recent studies suggest that this capacity is slowing down its increase in the last years. Several facts could be involved in this saturation of the terrestrial biosphere carbon (C) sink capacity. Night time warming, drought and nutrient limitation by phosphorus (P) or potassium (K) scarcity, among other factors may offset the CO2 and nitrogen (N) fertilization effects.

Earth could thus be shifting from the recent past period where terrestrial ecosystem processes have been dominated by C and N fertilization to a period with warming increasing at higher rates and thus with terrestrial ecosystem processes dominated by warming enhancement and extreme events and their associated effects.

This project aims to investigate how these warming, drought, and nutrient limitations and imbalances affect the C sink capacity of Earth terrestrial biosphere. We plan to use field experiments, observational studies, remote sensing, data mining, and modeling to test this likely shift of global change periods. We will conduct field experiments and observational studies in geographical and temperature gradients in boreal, wet temperate, Mediterranean and tropical regions. We will also conduct data mining studies to analyse the relationships between warming, drought, and nutrient availability and imbalances with the structure and fuctioning of organisms, population, communities and ecosystems productivity and net C accumulation.

In collaboration with other international research groups we will use all these data to improve the general C balances and climate model outputs under different future scenarios of CO2 emissions. We expect to reach a very substantial advance in the knowledge of the likely change from a fertilization dominated period to a warming dominated period in terrestrial biosphere and of the impacts of such shift on terrestrial biosphere.