Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo lâm nghiệp: "Temperate forest trees and stands under severe drought: a review of ecophysiological responses, adaptation processes and long-term consequences"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Temperate forest trees and stands under severe drought: a review of ecophysiological responses, adaptation processes and long-term consequences. | Ann. For. Sci. 63 2006 625-644 INRA EDP Sciences 2006 DOI 10.1051 forest 2006042 625 Review Temperate forest trees and stands under severe drought a review of ecophysiological responses adaptation processes and long-term consequences Nathalie BrEDAa Roland Hucb André GRANIERa Erwin DREYERa a UMR INRA UHP Forest Ecology and Ecophysiology INRA 54280 Champenoux France b Mediterranean Forest Research Unit INRA 84000 Avignon France Received 24 October 2005 accepted 28 April 2006 Abstract - The extreme drought event that occurred in Western Europe during 2003 highlighted the need to understand the key processes that may allow trees and stands to overcome such severe water shortages. We therefore reviewed the current knowledge available about such processes. First impact of drought on exchanges at soil-root and canopy-atmosphere interfaces are presented and illustrated with examples from water and CO2 flux measurements. The decline in transpiration and water uptake and in net carbon assimilation due to stomatal closure has been quantified and modelled. The resulting models were used to compute water balance at stand level basing on the 2003 climate in nine European forest sites from the CARBOEUROPE network. Estimates of soil water deficit were produced and provided a quantitative index of soil water shortage and therefore of the intensity of drought stress experienced by trees during summer 2003. In a second section we review the irreversible damage that could be imposed on water transfer within trees and particularly within xylem. A special attention was paid to the inter-specific variability of these properties among a wide range of tree species. The inter-specific diversity of hydraulic and stomatal responses to soil water deficit is also discussed as it might reflect a large diversity in traits potentially related to drought tolerance. Finally tree decline and mortality due to recurrent or extreme drought events are discussed on the basis of a literature review and .