文章信息：Karen C. Seto, Burak Güneralp, & Lucy R. Hutyra. (2012). Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proceedings of the National Academy of Sciences: 109(40), 16083–16088. https://doi.org/10.1073/pnas.1211658109
整理人：杨文，2023级硕士生
整理时间：2024年7月5日
Abstract: Urban land-cover change threatens biodiversity and affects ecosystem productivity through loss of habitat, biomass, and carbon storage. However, despite projections that world urban populations will increase to nearly 5 billion by 2030, little is known about future locations, magnitudes, and rates of urban expansion. Here we develop spatially explicit probabilistic forecasts of global urban land-cover change and explore the direct impacts on biodiversity hotspots and tropical carbon biomass. If current trends in population density continue and all areas with high probabilities of urban expansion undergo change, then by 2030, urban land cover will increase by 1.2 million km2, nearly tripling the global urban land area circa 2000. This increase would result in considerable loss of habitats in key biodiversity hotspots, with the highest rates of forecasted urban growth to take place in regions that were relatively undisturbed by urban development in 2000: the Eastern Afromontane, the Guinean Forests of West Africa, and the Western Ghats and Sri Lanka hotspots. Within the pan-tropics, loss in vegetation biomass from areas with high probability of urban expansion is estimated to be 1.38 PgC (0.05 PgC yr−1), equal to ∼5% of emissions from tropical deforestation and land-use change. Although urbanization is often considered a local issue, the aggregate global impacts of projected urban expansion will require significant policy changes to affect future growth trajectories to minimize global biodiversity and vegetation carbon losses.
摘要：城市土地覆盖变化威胁着生物多样性，并通过栖息地、生物量和碳储存的损失影响生态系统生产力。然而，尽管预测到2030年，世界城市人口将增加到近50亿，但人们对未来城市扩张的地点、规模和速度知之甚少。在这里，我们开发了全球城市土地覆盖变化的空间显式概率预测，并探讨了对生物多样性热点和热带碳生物量的直接影响。如果目前人口密度的趋势继续下去，所有城市扩张可能性高的地区都发生了变化，那么到2030年，城市土地覆盖面积将增加120万平方公里，几乎是2000年左右全球城市土地面积的三倍。这一增长将导致主要生物多样性热点地区的栖息地大量丧失，2000年预测的城市增长率最高的地区是相对未受城市发展影响的地区：东非、西非几内亚森林、西高止山脉和斯里兰卡热点地区。在泛热带地区，城市扩张概率高的地区的植被生物量损失估计为1.38 PgC（0.05 PgC yr−1），相当于热带森林砍伐和土地利用变化排放量的~5%。尽管城市化通常被视为一个局部问题，但预计城市扩张的总体全球影响将需要重大的政策变化，以影响未来的增长轨迹，从而最大限度地减少全球生物多样性和植被碳损失。
图 2030年全球城市扩张概率预测。城市扩张的数量和可能性存在显著差异（A）。大部分预测的城市扩张可能发生在中国东部（B）。一些地区在特定地点（C）有很高的城市扩张概率，而另一些地区有大面积的低概率城市增长（D）。虚线表示热带的北部和南部边界。
图 基于2030年转化概率的泛热带地区平均（MgC/ha）和总碳（PgC）损失
原文链接：https://www.pnas.org/doi/10.1073/pnas.1211658109
