四川植被净第一性生产力(NPP)对全球气候变化的响应

Response of net primary productivity (NPP) of Sichuan vegetations to global climate changes

根据全球气候变化的趋势 ,利用生态信息系统 (EIS)技术 ,采用植被净第一性生产力模型 ,并结合海拔因素 ,模拟了四川植被净第一性生产力在未来气候 5种水热条件下空间分布格局的变化趋势。结果表明 ,当前四川植被的净第一性生产力 (NPP)从总体上沿东南向西北呈逐渐递减趋势。植被净第一性生产力与降水量呈明显正相关关系 ,二者曲线比较近似。与可能蒸散率呈明显负相关关系 ,与海拔关系比较复杂。在盆地内 ,NPP值主要取决于降水量的多少。在盆地向高原过渡地区和高山高原地区 ,植被净第一性生产力主要取决于可能蒸散率的大小。随着全球气候的变化 ,四川省的植被净第一性生产力将沿东南至西北方向发生面积和值的推移。当温度升高 2 5℃ ,降水量增加 10 %时 ,四川省的植被净第一性生产力将增加13 76 % ,随着降水量增加到 2 0 % ,其值将进一步升高 ,达到 10 92 2TDM·hm-2 ·年 -1。当温度升高 4℃ ,降水量增加 10 %时 ,四川省的植被净第一性生产力将增加 18 2 9% ,随着降水量减少到P 10 %时 ,其值将逐渐减少到 9 5 30TDM·hm-2 ·年-1。

According to the trend of global climate changes and in combination with the elevation factor,the authors simulated the changes of spatial distribution pattern for net primary productivity (NPP) of Sichuan vegetations under 5 combinations of thermal and hydrological conditions using Ecologicol Information System ( EIS ) and the vegetations net primary productivity model.The result indicated that the net primary productivity (NPP)-values of natural vegetation in Sichuan decreases gradually from southeast to northwest.The NPP-values was positively related to precipitation,while negatively related to the PER-values.The relationship between the NPP-values and the elevation is very complicated.The NPP-values were mainly decided by precipitation in the basin,but by the potential evaporating rate (PER) in the transitional region and the plateau.With changes of the global climate,the values and distribution area of NPP will move from southeast to northwest of Sichuan Province.When the temperature and the precipitation increase by 2.5℃ and 10%,respectively,the NPP-values will increase by 13.76%.When the precipitation increases to 20%,the NPP-values will increase continually to 10.922 TDM·hm -2·yr -1.When the temperature increases by 4℃ and precipitation increases by 10%,the NPP-values will increase by 18.29%.With the decrease of precipitation to P-10%,NPP will decrease gradually to 9.530 TDM·hm -2·yr -1.