M. Broadmeadow

Forestry and climate change

Drawing together perspectives from researchers and policy makers, this book explores how forests will interact with the physical and natural world, and with human society as the climate changes. Also considered is how the worlds forests can be managed to contribute to the mitigation of climate change and to maximize the full range of economic and non-market benefits. Providing an examination of the science, a detailed consideration of the science policy interface and the international frameworks and conventions, this book is valuable reading for all those interested in sustainable forest management, climate change and the associated environmental sciences.

Soil (N) modulates soil C cycling in CO2-fumigated tree stands: a meta-analysis

Under elevated atmospheric CO(2) concentrations, soil carbon (C) inputs are typically enhanced, suggesting larger soil C sequestration potential. However, soil C losses also increase and progressive nitrogen (N) limitation to plant growth may reduce the CO(2) effect on soil C inputs with time. We compiled a data set from 131 manipulation experiments, and used meta-analysis to test the hypotheses that: (1) elevated atmospheric CO(2) stimulates soil C inputs more than C losses, resulting in increasing soil C stocks; and (2) that these responses are modulated by N. Our results confirm that elevated CO(2) induces a C allocation shift towards below-ground biomass compartments. However, the increased soil C inputs were offset by increased heterotrophic respiration (Rh), such that soil C content was not affected by elevated CO(2). Soil N concentration strongly interacted with CO(2) fumigation: the effect of elevated CO(2) on fine root biomass and -production and on microbial activity increased with increasing soil N concentration, while the effect on soil C content decreased with increasing soil N concentration. These results suggest that both plant growth and microbial activity responses to elevated CO(2) are modulated by N availability, and that it is essential to account for soil N concentration in C cycling analyses.