Plant communities have undergone dramatic changes in recent centuries, although not all such changes fit with the dominant biodiversity-crisis narrative used to describe them. At the global scale, future declines in plant species diversity are highly likely given habitat conversion in the tropics, although few extinctions have been documented for the Anthropocene to date (<0.1%). Nonnative species introductions have greatly increased plant species richness in many regions of the world at the same time that they have led to the creation of new hybrid polyploid species by bringing previously isolated congeners into close contact. At the local scale, conversion of primary vegetation to agriculture has decreased plant diversity, whereas other drivers of change-e.g., climate warming, habitat fragmentation, and nitrogen deposition-have highly context-dependent effects, resulting in a distribution of temporal trends with a mean close to zero. These results prompt a reassessment of how conservation goals are defined and justified.

中文翻译：

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人类世期间植物生物多样性跨尺度变化

近几个世纪以来，植物群落发生了翻天覆地的变化，尽管并非所有这些变化都符合用来描述它们的主要生物多样性危机叙述。在全球范围内，鉴于热带栖息地的转变，未来植物物种多样性的下降很有可能，尽管迄今为止人类世几乎没有记录到灭绝（<0.1%）。非本地物种的引入极大地增加了世界许多地区的植物物种丰富度，同时它们通过将先前孤立的同源物紧密接触而导致产生新的杂交多倍体物种。在地方尺度上，原始植被向农业的转变降低了植物多样性，而其他变化驱动因素，例如气候变暖、栖息地破碎化、和氮沉降 - 具有高度依赖于环境的影响，导致时间趋势分布的平均值接近于零。这些结果促使人们重新评估如何定义和证明保护目标。