全球陆地保护地与城市距离变化分析

在城市用地和保护地都快速扩张的背景下, 保护地与城市之间的距离在急剧缩小, 然而这并未引起人们的足够关注。城市对保护地的负面影响具有尺度效应, 且随着距离的接近, 负面影响也将加剧, 因此保护地与城市距离的远近可成为衡量负面影响大小的重要依据。本文基于全球保护地和大城市及城市用地分布数据, 对全球、洲际、地区和国家尺度1950-2010年城市与保护地距离的变化进行分析。结果表明: (1)在4个尺度上, 保护地与城市的距离都在不断缩小。欧洲和西欧是保护地与城市距离最近的洲和地区, 而大洋洲和澳大利亚及新西兰则是距离最远的洲和地区。在面积排名前20的保护地大国中, 中国是保护地与城市平均最近距离最小的国家, 其与50万以上人口城市的平均最近距离在2010年仅为143.5 km。(2)根据城市与保护地距离的现状及其变化, 可将保护地排名前60的国家分成5类: (a)距离很近, 靠近速度慢, 如西欧国家; (b)距离近, 靠近速度适中, 如中国、美国; (c)距离较近, 靠近速度快, 如沙特阿拉伯、厄瓜多尔; (d)距离较远, 靠近速度较慢, 如巴西、加拿大、俄罗斯联邦; (e)距离远, 靠近速度较快, 如澳大利亚、非洲大多数国家。(3)全球范围内, 越来越多生物多样性较高的保护地将面临被城市影响的境地。该结果以期引起大家对全球保护地与城市距离急剧缩短现象的关注和警惕。

Analysis of change in the distances between global terrestrial protected areas and urban areas

With the expansion of urban areas and protected areas (PAs), the distance between them is strongly declining. However, this phenomenon hasn’t garnered much attention. The negative influences of urban areas on PAs have scaling effects, and with this distance decreasing, those negative influences may compound, therefore the distance between PAs and urban areas could be an important reference for measuring these negative influences. Based on spatial data of PAs, cities and urban areas, our study analyzed the changes in distance from PAs to urban areas between 1950 to 2010 at global, continental, regional and national scale. The results showed that: (1) at these four scales, the distance between PAs to urban areas were all declining. Europe (Western Europe) was the continent (region), which had the closest proximity of PAs and urban areas. On the contrary, Oceania (Australia and New Zealand) was the continent (region), which had the farthest proximity of these areas. Among the top 20 PAs countries, China had the nearest proximity, as the mean distance from PAs to cities with more than 50 thousand people was merely 143.5 km. (2) According to the current situation and changes in the distances between PAs and urban areas, the top 60 PAs countries can be divided into 5 categories: (a) the proximity was very near and the speed of changes was slow, such as Western European countries; (b) the proximity was near and the speed was moderate, such as China and America; (c) the proximity was relatively near and the speed was rapid, such as Saudi Arabia and Ecuador; (d) the proximity was relatively distant and the speed was relatively slow, such as Brazil, Canada and Russia; (e) the proximity was distant and the speed was relatively rapid, such as Australia and most African countries. (3) On a global scale, more and more PAs with high biodiversity are influenced by urbanization. This study may draw attention and awareness to the changing proximity between PAs and urban areas.