Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch 7602, South Africa; Theoretical Ecology Group, Department of Mathematical Sciences, Stellenbosch University, Stellenbosch 7602, South Africa; African Institute for Mathematical Sciences, Cape Town 7945, South Africa.
Curr Biol. 2019 Sep 9;29(17):2912-2918.e2. doi: 10.1016/j.cub.2019.07.063. Epub 2019 Aug 22.
During the Anthropocene, humans are changing the Earth system in ways that will be detectable for millennia to come [1]. Biologically, these changes include habitat destruction, biotic homogenization, increased species invasions, and accelerated extinctions [2]. Contemporary extinction rates far surpass background rates [3], but they seem remarkably low in plants [4, 5]. However, biodiversity is not evenly distributed, and as a result, extinction rates may vary among regions. Some authors have contentiously argued that novel anthropic habitats and human-induced plant speciation can actually increase regional biodiversity [6, 7]. Here, we report on one of the most comprehensive datasets to date, including regional and global plant extinctions in both biodiversity hotspots (mostly from Mediterranean-type climate regions) and coldspots (mostly from Eurasian countries). Our data come from regions covering 15.3% of the Earth's surface and span over 300 years. With this dataset, we explore the trends, causes, and temporal dynamics of recent plant extinctions. We found more, and faster accrual of, absolute numbers of extinction events in biodiversity hotspots compared to coldspots. Extinction rates were also substantially higher than historical background rates, but recent declines are evident. We found higher levels of taxonomic uniqueness being lost in biodiversity coldspots compared to hotspots. Causes of plant extinctions also showed distinct temporal patterns, with agriculture, invasions, and urbanization being significant drivers in hotspots, while hydrological disturbance was an important driver in coldspots. Overall, plant extinctions over the last three centuries appear to be low, with a recent (post-1990) and steady extinction rate of 1.26 extinctions/year.
在人类世，人类正在以可以在未来几千年内被探测到的方式改变地球系统[1]。在生物学方面，这些变化包括生境破坏、生物均质化、物种入侵增加和物种灭绝加速[2]。当代灭绝率远远超过背景率[3]，但在植物中似乎非常低[4,5]。然而，生物多样性分布不均，因此，灭绝率可能因地区而异。一些作者有争议地认为，新型人类栖息地和人类诱导的植物物种形成实际上可以增加区域生物多样性[6,7]。在这里，我们报告了迄今为止最全面的数据集之一，其中包括生物多样性热点地区（主要来自地中海气候地区）和冷点地区（主要来自欧亚国家）的区域和全球植物灭绝[8]。我们的数据来自覆盖地球表面 15.3%的地区，跨越 300 多年。利用这个数据集，我们探讨了最近植物灭绝的趋势、原因和时间动态。我们发现，与冷点地区相比，生物多样性热点地区的绝对灭绝事件数量更多，而且增加得更快[9]。灭绝率也明显高于历史背景率，但最近的下降趋势明显[10]。我们发现，与热点地区相比，冷点地区失去的分类独特性水平更高[11]。植物灭绝的原因也显示出明显的时间模式，农业、入侵和城市化是热点地区的重要驱动因素，而水文干扰是冷点地区的重要驱动因素[12]。总的来说，过去三个世纪的植物灭绝似乎很低，最近（1990 年后）的灭绝率稳定在每年 1.26 次[13]。
