北京大學(xué)城市與環(huán)境學(xué)院樸世龍教授研究小組最近在PNAS 上報道了他們在氣候變化對北美植被生長影響研究方面取得的新進(jìn)展。
植被生長對氣候變化的響應(yīng)是全球變化研究的重要內(nèi)容之一,。遙感數(shù)據(jù)表明,，盡管上世紀(jì)80年代和90年代，北半球植被生產(chǎn)力呈顯著增加趨勢,，但在本世紀(jì)初，這一增加趨勢停止甚至減少?？茖W(xué)家們普遍認(rèn)為，這一現(xiàn)象與全球氣候變暖所導(dǎo)致的干旱有關(guān),。北京大學(xué)城市與環(huán)境學(xué)院全球氣候變化研究小組,，利用長期的遙感數(shù)據(jù)和氣候觀測數(shù)據(jù)，借助遙感,、GIS等新技術(shù)的支持,，綜合研究北美陸地植被生長的時空格局及其機(jī)制。研究小組發(fā)現(xiàn),，北美西北大部分地區(qū)自上世紀(jì)90年代以來植被生產(chǎn)力下降的現(xiàn)象不能由干旱脅迫解釋,，而是與該地區(qū)春季溫度下降密切相關(guān)。
論文的通訊作者樸世龍教授主要從事陸地生態(tài)系統(tǒng)對全球氣候變化的響應(yīng)及其反饋?zhàn)饔玫难芯?，是?lián)合國政府間氣候變化專門委員會（IPCC）第五次評估報告第一工作組全球碳循環(huán)章節(jié)的主要作者（Lead Author）之一,。論文的第一作者王旭輝是樸世龍教授的碩士一年級學(xué)生。
本研究得到國家自然科學(xué)基金資助,。（生物谷Bioon.com）
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.1014425108
Spring temperature change and its implication in the change of vegetation growth in North America from 1982 to 2006
Xuhui Wanga, Shilong Piaoa,1, Philippe Ciaisb, Junsheng Lic,1, Pierre Friedlingsteinb,d, Charlie Kovene, and Anping Chenf
Abstract
Understanding how vegetation growth responds to climate change is a critical requirement for projecting future ecosystem dynamics. Parts of North America (NA) have experienced a spring cooling trend over the last three decades, but little is known about the response of vegetation growth to this change. Using observed climate data and satellite-derived Normalized Difference Vegetation Index (NDVI) data from 1982 to 2006, we investigated changes in spring (April–May) temperature trends and their impact on vegetation growth in NA. A piecewise linear regression approach shows that the trend in spring temperature is not continuous through the 25-year period. In the northwestern region of NA, spring temperature increased until the late 1980s or early 1990s, and stalled or decreased afterwards. In response, a spring vegetation greening trend, which was evident in this region during the 1980s, stalled or reversed recently. Conversely, an opposite phenomenon occurred in the northeastern region of NA due to different spring temperature trends. Additionally, the trends of summer vegetation growth vary between the periods before and after the turning point (TP) of spring temperature trends. This change cannot be fully explained by summer drought stress change alone and is partly explained by changes in the trends of spring temperature as well as those of summer temperature. As reported in previous studies, summer vegetation browning trends have occurred in the northwestern region of NA since the early 1990s, which is consistent with the spring and summer cooling trends in this region during this period.
