MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
Forest Ecology and Conservation Group, Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, U.K.
Biol Rev Camb Philos Soc. 2019 Oct;94(5):1636-1657. doi: 10.1111/brv.12519. Epub 2019 May 6.
Land-use change is fragmenting natural ecosystems, with major consequences for biodiversity. This paper reviews fragmentation trends - historical and current - in China, the fourth largest country on Earth, and explores its consequences. Remote sensing makes it possible to track land-use change at a global scale and monitor fragmentation of dwindling natural landscapes. Yet few studies have linked fragmentation mapped remotely with impacts on biodiversity within human-modified landscapes. Recent reforestation programs have caused substantial increases in forest cover but have not stopped fragmentation, because the new forests are mostly monocultures that further fragment China's remnant old-growth lowland forests that harbour the highest levels of biodiversity. Fragmentation - and associated biodiversity declines - is unevenly distributed in China's forests, being most problematic where agricultural expansion is occurring in the southwest and northeast, serious in the densely populated eastern regions where urbanisation and transport infrastructure are modifying landscapes, but less of a problem in other regions. Analyses of temporal trends show that the drivers of forest fragmentation are shifting from mainly agricultural expansion to urbanisation and infrastructure development. Most of China's old-growth forests persist in small, isolated fragments from which many native species have disappeared, on land unsuitable for human utilisation. Fragmentation throughout China is likely to have major consequences on biodiversity conservation, but few studies have considered these large-scale processes at the national level. Our review fills this research gap and puts forward a systematic perspective relevant to China and beyond.
土地利用变化正在使自然生态系统破碎化，对生物多样性产生重大影响。本文回顾了中国作为世界第四大国家的土地利用变化趋势（历史和现状），并探讨了其后果。遥感技术使我们能够在全球范围内跟踪土地利用变化，并监测不断减少的自然景观的破碎化。然而，很少有研究将远程映射的破碎化与人类改造景观内对生物多样性的影响联系起来。最近的造林计划使森林覆盖率大幅增加，但并没有停止破碎化，因为新的森林主要是单一树种，进一步割裂了中国剩余的低地原始森林，这些森林拥有最高水平的生物多样性。破碎化——以及随之而来的生物多样性下降——在中国的森林中分布不均，在西南和东北农业扩张的地区最为严重，在人口稠密的东部地区，城市化和交通基础设施正在改变景观，情况也很严重，但在其他地区则不是问题。对时间趋势的分析表明，森林破碎化的驱动因素正在从主要的农业扩张转向城市化和基础设施发展。中国的大部分原始森林都存在于小而孤立的碎片中，许多本地物种已经从这些碎片中消失，这些碎片所在的土地不适宜人类利用。中国各地的破碎化很可能对生物多样性保护产生重大影响，但很少有研究从国家层面考虑这些大规模的过程。我们的综述填补了这一研究空白，并提出了一个与中国及其他地区相关的系统观点。
