中國植被覆蓋度變化及其主要影響因素

Vegetation Coverage Change in China and Its Main Influ-encing Factors

張家欣(JIA-XIN ZHANG) ； 徐國策(GUO-CE XU) ； 李鵬(PENG LI) ； 張譯心(YI-XIN ZHANG) ； 王斌(BIN WANG) ； 賈路(LU JIA)

《台灣水利》 67卷2期 (2019/06) Pp. 58-66

摘要

植被是地表能量交換、水循環、生物地球化學循環和氣候系統相互聯繫的關鍵介質。本研究通過數理統計、Hurst指數等方法對我國植被覆蓋度的時空變化特徵進行了分析，並研究了其與氣候、地形之間的響應關係，結果表明：2000～2013年期間，中國植被覆蓋度呈顯著（p ＜ 0.05）增加趨勢，面積佔比在85%以上，北方地區的增加趨勢相較南方更為顯著。植被覆蓋度與氣候之間的相關關係具有空間異質性，水熱充沛地區，降水不是植被生長的限制性因子，溫度會對植被的生長產生一定促進或抑製作用，而乾旱地區降水與植被覆蓋度之間的相關性相對於氣溫來說更為顯著。在不考慮氣溫要素的情況下，降水量帶在400～500 mm範圍內時，“胡煥庸線”附近植被恢復最穩定，E值穩定在0.88。全國植被覆蓋度與年氣溫之間的相關性分佈存在較大差異，乾旱地區，氣溫升高會導致降水減少，從而抑制植被的生長。濕潤地區，降水不是限制植被生長的因子，氣溫的升高會高對植被生長起促進作用。坡度與植被覆蓋度之間存在著非線性關係，坡度在15～25°時植被覆蓋度增幅最大。

關鍵字

植被覆蓋度 ； 降水 ； 地形 ； 時空變化 ； 相關關係

並列摘要

Vegetation is the most critical medium in terms of energy exchange, water cycle, biogeochemical cycle and climate system in terrestrial surface. Based on mathematical statistics and the Hurst exponent index method, the study analyzed the spatial and temporal characteristics of vegetation coverage change and the relationship between vegetation change and climate and topography in China. The results showed that the vegetation coverage in China hada significant increasing trend from 2000 to 2013, with an increase of more than 85%. This phenomenon is more significant in the northern rather than the south. The response of vegetation coverage to climate has a strong spatial heterogeneity. In hydrothermal areas, precipitation is not a limiting factor for vegetation growth, temperature will promote or inhibit the growth of vege-tation. When it comes to precipitation and vegetation coverage in arid areas, the cor-relation between them is more pronounced than the temperature. Without considering the temperature elements, the precipitation is in the range of 400~500 mm, the vege-tation restoration near the ＂Hu Line＂ is the most stable, and the E value is stable at 0.88. There is a big difference in the correlation between the national vegetation cov-erage and the annual temperature. In arid regions, rising temperatures will lead to a decrease in precipitation, thereby inhibiting the growth of vegetation. In humid areas, precipitation is not a limiting factor vegetation growth, and elevated temperatures will contribute to vegetation growth. The response of vegetation coverage to slope shows a significant nonlinear relationship. The slope with the largest increase in vegetation coverage is 15~25 degree.

並列關鍵字

Vegetation coverage ； Precipitation ； Topography ； Temporal and spatial variation ； Relationship