大自然实木床味道:北京植被变化

近50年北京植被对全球变暖的响应及其时效——基于遥感数据和物候资料的分析

稿件摘要:植被对全球变暖的响应方式及其程度问题是全球变化研究的焦点之一。利用1951～2000年的气温、降水等气候资料、1982～2000年的NOAA/AVHRR遥感数据和1951～2002年山桃始花的物候数据，分析了北京各气候参量与生态系统植被在年际和年内时间尺度上的变化规律及其关系。结果表明，北京近20年增温1?2℃，增温态势显著；过去50年中，降水的年际变化小于生长季内的波动幅度。年NDVI最大值（VP）、平均值（VM）的年际变化曲线呈波动中缓慢上升的趋势，表明植被的生长状况总体上在变好或生长季在延长。VP出现日期（VPD）提前，20世纪90年代比80年代提前4.5 d。山桃始花物候期的分析表明，北京1988年以后春季开始日期提前9.63 d。时间尺度不同，各个气候指标对各植被指标的影响程度不同：①年际时间尺度，年均温影响VP、VM的时效为1年；月际水平上，除温度影响VM的时效为2个月外，各气候参量影响VP、VM的时效为1个月。年际尺度上，温度影响山桃始花时效为2年；月际尺度上，2、3、4月份温度影响山桃始花日期。关键词:NDVI，全球变暖，山桃始花日期，累积距平，时滞，互相关分析. 中图分类号:Q948.12;文献标识码:A;文章编号:1000-4890(2005)02-0123-08 Impacts and lags of global warming on vegetation in Beijing for the last 50 years based on remotely sensed data and phonological information. ZHANG Xuexia1,GE Quansheng2,ZHENG Jingyun2 (1College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China;2Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing 100101, China).Chinese Journal of Ecology,2005，24(2)：123～130. Abstract: Global changes focus on the impacts and feedbacks of global warming on terrestrial ecosystem. Based on climate data (temperature, precipitation etc.) of 1951～2000, NOAA/AVHRR NDVI data of 1982～2000 and foliage phenology data of 1951～2002,impacts of short term seasonal and inter?annual climate changes on zonal ecosystem in Beijing were discussed. The results showed that climate changes presented increasing temperature and fluctuant precipitation in the past 50 years in the study area. Annual NDVI peak value and NDVI mean value could reflect preferably climate changes, and the trends of them appeared increased in some degree among oscillations in the past 20 years, which meant a better condition for vegetation growth or longer growing days in the study area. The VP date was earlier 4.5d in 1990s than that in 1980s.The advance of Prunus davidiana flowering phenophase showed that the spring came 9.63 d ahead since 1988 in study region .Statistical analyses indicated that land surface temperature in Beijing has more significant relations with NDVI and the flowering phenophase than with precipitation as a whole. Different time scales led to different relations between climate indexes and growing conditions of plants. At the scale of a year,there were closer relations between AT,AP and NDVI; while at the scale of a month, there were closer relations between ET,EP and NDVI. Key words: NDVI, global warming, Prunus davidiana flowering phenophase, cumulate anomaly, time lags, cross?correlation analysis.