环杭州湾地区自然植被净初级生产力的变化特征及其成因

利用1971—2006年环杭州湾地区25个气象站的降水、温度和云量资料及全球CO2年平均体积分数资料,采用LPJ全球动态植被模式（Lund-Potsdam-Jena Dynamic Global Vegetation Model）,通过模拟环杭州湾地区的植被年净初级生产力（Annual Net Primary Productivity,ANPP）,分析了该地区ANPP的变化特征,并探讨了植被ANPP变化的可能原因。结果表明：1）就环杭州湾地区,36a间植被ANPP均表现出不同程度的增加,尤其以嘉兴市北部、绍兴市东部较明显;全区平均增加速率为1.5243g·m-2·a-2;2）通过多元线性回归分析发现,环杭州湾地区平均云量与植被ANPP的关系最为密切,偏相关系数为-0.5175,而温度、降水与植被ANPP的关系不明显;同时,植被ANPP对气候变化的响应存在一定的地域性差异;3）在全区平均情况下,36a间由温度下降、降水增加、云量减小、CO2体积分数升高引起的植被ANPP变化趋势分别为-0.0813、-0.0171、0.7601、0.8673g·m-2·a-2,其对应的贡献率分别为-5.18%、-1.09%、48.38%、55.21%。由此可见,该地区植被ANPP变化的主要强迫因子是CO2体积分数和云量,而降水变化对植被ANNP的变化作用不大。

Characters of natural vegetation net primary productivity and their driving factors in the region around Hangzhou Bay

Based on data of the precipitation,temperature and cloud cover of 25 stations in Hangzhou Bay region and the global annual volume fraction of CO2 from 1971 to 2006,the annual vegetation net primary productivity （ANPP） is simulated by the LPJ mode l （Lund-Potsdam-Jena dynamic global vegetation model）.The temporal and spatial characters of the ANPP in the region are analyzed and the driving factors of ANPP are further investigated.Results show that：1）The average increasing rate of ANPP is 1.524 3 g·m-2·a-2 in the whole region.However,ANPP spatially show different increasing rates from 1971 to 2006,with the significant rate in the north of Jiaxing and the east of Shaoxing.2） The multiple linear regression analysis shows that there is a close relationship between cloud cover and ANPP with-0.517 5 partial correlation coefficient.However,the correlation between ANPP and temperature （precipitation） is inconspicuous.Response of ANPP to climate change shows a certain geographical distribution for the different hydro-thermal conditions.3）In the whole region around Hangzhou Bay,the average trends caused by decline of temperature,increase of precipitation,reduction of cloud cover and enhancement of volume fraction of CO2 are-0.081 3,-0.017 1,0.760 1,and 0.867 3 g·m-2·a-2,and their attributions to the change of ANPP are-5.18%,-1.09%,48.38% and 55.21%,respectively.Therefore,the changes of volume fraction of CO2 and cloud cover play important roles to affect the change of ANPP,however,change of precipitation has little action to the ANNP.