中国道路网引起的景观破碎格局及其对保护区的影响

道路的修建往往带来景观破碎、生态系统功能受损等后果。有关道路网络的生态影响格局及其影响因素,是当前道路生态学、地理空间分析等领域共同关注的问题。本文利用2015年全国道路网络数据,采用定量空间分析方法,刻画了当前中国铺装道路所引起的陆表景观破碎的格局特征,并分析了道路网络对自然保护区的干扰及与多变量的影响关系。结果表明：① 全国铺装道路的生态影响面积占陆地面积的10%,将陆表切割成3万多个斑块,并呈现小斑块数目众多,大斑块数目较少的分布特点;同时,陆表破碎化程度呈现明显的东西分异规律,空间格局与人口分布、经济发展水平等影响因素的地理分布规律趋同;② 全国约58%的自然保护区受到道路干扰,保护区的受干扰情况存在高等级保护区受干扰弱、低等级保护区次之、国家公园受干扰程度最强等差异特征,且国家公园处于受干扰高于未设保护区域的状态;③ 主要人类活动因素与保护区受干扰程度呈正相关,保护区面积、地形因素与受干扰程度呈负相关,具有面积小、受保护等级低、位于平原地区、气候适宜等特征的保护区更易受到道路干扰,处于已经受到人类活动破坏,生态脆弱的状态。因此,中国道路建设应追求社会发展与生态保护双平衡,同时道路干扰受到自然以及人文要素的共同作用,在相关影响机制研究和生态保护政策制定中应进行综合考虑。

Assessing the Impacts of China's Road Network on Landscape Fragmentation and Protected Areas

Road construction often leads to landscape fragmentation and damages ecosystem functions, such ecological impacts and consequences have been widely studied in the field of road ecology and geospatial analysis. This paper aims at exploring the influences of the road network in China. With spatial data analysis and the data set of nationwide roads in 2015, we characterized the landscape fragmentation patterns caused by paved roads, estimated the impacts on protected areas, and then explained the relationship between the degree of impacts and multiple environmental variables. The results show that: (1) The area affected by the paved roads in China have reached 10% of the terrestrial areas. The land surface have been cut into over 30 000 patches. The number of small patches is numerous, and the number of large patches is less. The extent of land surface fragmentation presents obvious east-west differentiation, and the spatial pattern of the roadless patches is similar to the population distribution and economic development level. (2) About 58% of the protected areas suffer from road influences. The degree of influence increases as the level of establishment of the protected areas decreases. The national parks have been interfered stronger than the unprotected areas. (3) The main human activity factors were positively correlated with the degree of disturbance on the protected areas, and the size of protected areas and topographic factors were negatively correlated with the degree of interference. Small areas, low level protected areas, plain areas, climate-friendly protected areas are susceptible to road disturbances and are in a state of being affected seriously by human activities. Therefore, China's road construction should achieve a balance between social development and ecological protection. Road disturbances are affected by natural and human factors, which should be considered comprehensively in the study of relevant impact mechanisms and the formulation of environmental protection policies.