城市化对昆虫多样性的影响

Impacts of urbanization process on insect diversity

自20世纪以来,城市化在世界范围内迅猛发展,已有一半以上的人口居住在城市中。通过对当前国内外有关城市化对昆虫多样性影响的研究分析,城市化主要对昆虫的丰富度、空间分布、灭绝、食性及生态系统服务功能5个方面产生影响。城市化导致了大多数本地昆虫种群衰退,在空间分布上,沿郊区–城市中心梯度(rural–city center gradient,RCG),本地昆虫的丰富度下降明显,部分本地昆虫甚至在城市化进程中灭绝。城市化造成大多数专食性昆虫种群数量下降,广食性昆虫如蚜虫、蟑螂、白蚁等的种群数量略有上升。与捕食性昆虫相比,植食性、寄生性、腐食性和访花性昆虫对城市化的负面响应更为明显,因此降低了城市昆虫的生态系统服务功能。城市地区,昆虫种群数量下降主要与城市化所带来的环境污染(大气污染、水体污染、光污染及热污染)、生境破碎化、道路硬化、人工建筑增加和入侵物种引入有关。随着城市化进程的不断发展,对城市昆虫的保护需要从科学研究、生境恢复及公众环保知识普及等方面做起。

Rapid worldwide urbanization during the last century has led to more than half the world’s population living in urban regions. Studies of how urbanization affects insect diversity have focused on the following： insect abundance, distribution, extinction, food habits and ecosystem services. Native insect populations have declined greatly in urban areas, where studies of their spatial distribution have revealed that abundance decreases along what is termed the rural–city center gradient （RCG）, many native insects even extinct with urbanization process. Most specialist insect communities have declined in abundance due to urbanization, while some generalist species, such as aphids, cockroaches and termites, have increased slightly in abundance. It is also the case that herbivorous, parasitic, saprophagous and flower-visiting insects are much more negatively influenced by urbanization than predator insects. This has a significant effect on the ecosystem services of insects. The decline of many insects due to urbanization can be attributed to environmental pollution （including air pollution, water pollution, light pollution, and heat pollution）, habitat fragmentation, road hardening, clustering of buildings, and occurrence of introduced invasive species. As urbanization continues, measures should be taken to protect insects in urban areas. This will entail improving basic scientific research on the problem, construction of suitable habitats, and informing the general public of the benefits of environmental protection.