Data from: The present and future effects of land use on ecological assemblages in tropical grasslands and savannas in Africa

The world is currently experiencing a period of rapid, human-driven biodiversity loss. Over the past decade, numerous metrics for biodiversity have been used to create indicators to track change in biodiversity. However, our ability to predict future changes has been limited. In this study, we use two very different models to predict the status and possible futures for the composition and diversity of ecological assemblages in African tropical grasslands and savannas under land-use change. We show that ecological assemblages are affected more by land use in African grasslands and savannas than in other biomes. We estimate that average losses of assemblage composition and diversity are already between 9.7 and 42.0%, depending on the model and measure used. If current socio-economic trajectories continue (‘business-as-usual’), the likely associated land-use changes are predicted to lead to a further 5.6–12.3% loss of assemblage composition and diversity. In contrast, a scenario that assumes more efficient use of agricultural areas (thus requiring a smaller total area) could be associated with a partial reversal ‒ of as much as 3.2% ‒ of past losses. While the agriculture that causes the majority of land-use change is an important source of economic growth, projections of the effects of land use on ecological assemblages can allow for more informed decisions.

当前全球正经历由人类活动主导的快速生物多样性丧失阶段。过去十余年间，学界已基于多种生物多样性度量指标构建了监测生物多样性变化的指示体系。然而，当前我们对生物多样性未来变化的预测能力仍较为有限。本研究采用两种差异显著的模型，针对土地利用变化情境下非洲热带草原与稀树草原的生态群落（ecological assemblages）组成与多样性现状及未来演化趋势开展预测。研究发现，相较于其他生物群系，非洲草原与稀树草原的生态群落受土地利用的影响更为显著。据估算，受所用模型与度量指标差异影响，当前生态群落组成与多样性的平均损失率已达9.7%至42.0%。若延续当前社会经济发展轨迹（即"照常经营"（business-as-usual）情景），则由此引发的土地利用变化预计将导致生态群落组成与多样性进一步损失5.6%至12.3%。与之形成对比的是，若采用更高效的农业用地利用模式（从而减少总用地需求），则可实现对既往损失的部分挽回，最大挽回幅度可达3.2%。尽管引发多数土地利用变化的农业活动是经济增长的重要支撑，但对土地利用给生态群落带来的影响进行预测，可为科学决策提供更充分的依据。