Climate control of terrestrial ecosystem CO2 sequestration

Cuny Queens College, Flushing NY

Investigators

Abstract

Climate control of terrestrial ecosystem CO2 sequestration Relationships between climate and the net exchange of carbon dioxide (CO2) between the atmosphere and biosphere on yearly to decadal scales are poorly known. This is a critical knowledge gap for models used to estimate long-term climate change impacts on both the biosphere and the rate of change of CO2 in the atmosphere. A pilot study, based on large databases from more than 100 observational sites over 6 continents with a total of 583 site-years of observations, suggests that the net flow of carbon into or out of ecosystems is highly correlated with: (1) mean annual temperature at mid- and high-latitudes, (2) water stress at mid- and low-latitudes, and (3) both temperature and water stress around the mid-latitudinal belt. On average, the influence of water stress on terrestrial ecosystem CO2 uptake exceeds the influence of temperature at mean annual temperatures above 16 C. This project will explore the ecological and physical mechanisms behind these initial results and develop a clearer understanding of the relative importance of temperature and water availability on carbon sequestration. This research is essential to understanding how future climate change is likely to alter the exchange of CO2 between the biosphere and the atmosphere. The consensus of science represented by the Intergovernmental Panel on Climate Change (IPCC) is that over the 21st century warming will be greatest at high northern latitudes, while projected decreases in precipitation are likely over much of the terrestrial subtropical zone. Results of this project will provide an empirical model based on real-world data of how the most likely future climate change scenarios would affect the potential capacity of terrestrial CO2 uptake in high latitudes and low latitudes. The analysis and synthesis of information proposed here is based on a large dataset provided by more than 100 research groups around the world. Collaboration, communication, and co-authorship will be established among a large number of scientists who collect these data. Two lectures will be developed for a non-major course that serves >250 students, and will incorporate basic concepts of physiological ecology and climatology based on this research. The lectures will bring current research into a classroom with perhaps the most ethnically diverse student body in the nation.