近30年河北大海陀自然保护区山地草甸植被(NDVI)变化及其对气候的响应

河北大海陀自然保护区地处我国暖温带落叶阔叶林区,草甸植被多处于山地顶部,对外界干扰敏感。为了研究该地区的草甸植被变化以及其对气候变化的响应,收集了该地区近30年的TM遥感影像资料,1980—2015年的气候数据,包括年平均气温、7月份平均气温、1月份平均气温、年降水量、6—8月平均降水量等多个气候指标,以及大海陀自然保护区及其周边地区的地形数据等,用滑动平均法、M-K检验法、相关分析法及偏相关分析法等方法分析了大海陀自然保护区草甸植被NDVI及其与气候响应。结果表明:(1)近30年来,大海陀自然保护区草甸植被NDVI呈先上升后下降的趋势,在2004年NDVI达到最高,随后逐渐下降。(2)大海陀自然保护区草甸区域的年降水量变化整体表现为波动循环的趋势,总体略有上升,但没有达到显著水平;年均温变化表现为上升趋势,且达到了极显著水平,该地区的气温上升趋势主要由以1月为主的冬季温度升高而引起。(3)草甸植被NDVI与年均温成显著的负相关关系,与年降水量的关系不明显。

Climate effects on NDVI change of upland meadow in Dahaituo Nature Reserve over 30 years

Hebei Dahaituo Nature Reserve is located in a warm, temperate, deciduous broad-leaved forest area in China. Meadow vegetation, which are sensitive to outside interference, are mainly distributed on top of Dahaituo Mountain. To determine the change and response of vegetation to climate change in the Dahaituo Nature Reserve and surrounding area, we collected a series of data, including Thematic Mapper(TM) remote sensing image data for the last 30 years and climate data from 1980 to 2015, including annual average temperature, average temperature in July, average temperature in January, annual precipitation, average precipitation in June to August, and terrain data. We analysed the relationship between the change in the meadow vegetation Normalized Difference Vegetation Index (NDVI) and climate change using the moving average method, the M-K method, correlational analyses, and partial correlation analyses. The results showed that:(1) NDVI of the meadow vegetation in Dahaituo Nature Reserve showed a downward trend in the past 30 years, after rising, achieved the best growth conditions in 2003, then gradually decreased. (2) The change in annual precipitation varied, but generally increased slightly. Annual average temperature showed a significant upward trend, with the temperature rise mainly caused by increased winter (January) temperatures. (3) NDVI of the meadow vegetation and average annual temperature were negatively correlated, whereas NDVI of the meadow vegetation and annual precipitation tended to be positively associated.