秦岭牛背梁植被覆盖变化及其对气温的时空响应

Variations of Vegetation Coverage and Its Response to Air Temperature at Niubeiliang of Qinling Mountains

[目的]揭示牛背梁保护区植被覆盖变化特征及其对区域气温的响应机理,为牛背梁地区的生态建设和管理提供依据。[方法]基于秦岭1975—2013年气温数据和2000—2013年NDVI数据,运用GIS空间分析技术以及相关检验和回归分析方法。[结果](1)近40a来牛背梁地区年均温增加速率为0.30℃/10a,1999年增温趋势达到显著水平。(2)2000—2013年研究区植被变化呈不显著的减少趋势,且季节和区域差异较大。(3)年尺度上,植被NDVI与气温整体呈正相关关系。季尺度上,春季植被NDVI与气温均呈显著正相关;夏季NDVI与气温呈不显著正相关;而秋季主要呈负相关。月尺度上,随植被生长阶段的变化,不同月份植被NDVI对气温的响应程度也有差异。[结论]牛背梁地区NDVI与气温关系密切,一年之中,5月植被对气温反应最敏感,且中高海拔地区的植被对气温的响应比低海拔植被更加敏感。

[Objective]To obtain the mechanisms of vegetation coverage variations and its response to the regional air temperature in Niubeiliang Natural Reserve so as to provide the references for eco-construction and management for this region.[Methods]Based on the air temperature data from 1975 to 2013and NDVI data during 2000—2013of Qinling Mountains,GIS spatial analysis techniques,relevant test and regression analysis method was utilized.[Results]（1）During the last 40 years,the air temperature increasing rate was0.30 ℃/10 a,the warming trend was abrupt in 1999.（2）Vegetation in this region had an insignificant reducing trend from 2000 to 2013,but had relative big seasonal and regional variations.（3）When observed at annual scale,NDVI mainly correlated positively with air temperature;at seasonal scale,spring NDVI showed a significant positive correlation with air temperature;NDVI of summer and air temperature showed an insignificant positive correlation;correlation between NDVI of autumn and the temperature was negative.At monthly scale,vegetation had different responses to NDVI.[Conclusion]NDVI was closely related to the air temperature,and was mostly sensitive to the temperature variation in May.Vegetation at middle and high altitude areas was more sensitive to temperature variation than the one at low altitude.