1. Quantifying the impact of habitat disturbance on ecosystem function is critical to understanding and predicting the future of tropical forests. Many studies have examined post‐disturbance changes in animal traits related to mutualistic interactions with plants, but the effect of disturbance on plant traits in diverse forests has received much less attention.
2. Focusing on two study regions in the eastern Brazilian Amazon, we used a trait‐based approach to examine how seed dispersal functionality within tropical plant communities changes across a landscape‐scale gradient of human modification, including both regenerating secondary forests and primary forests disturbed by burning and selective logging.
3. Surveys of 230 forest plots recorded 26,533 live stems from 846 tree species. Using herbarium material and literature, we compiled trait information for each tree species, focusing on dispersal mode and seed size.
4. Disturbance reduced tree diversity and increased the proportion of lower wood density and small‐seeded tree species in study plots. Disturbance also increased the proportion of stems with seeds that are ingested by animals and reduced those dispersed by other mechanisms (e.g. wind). Older secondary forests had functionally similar plant communities to the most heavily disturbed primary forests. Mean seed size and wood density per plot were positively correlated for plant species with seeds ingested by animals.
5. Synthesis . Anthropogenic disturbance has major effects on the seed traits of tree communities, with implications for mutualistic interactions with animals. The important role of animal‐mediated seed dispersal in disturbed and recovering forests highlights the need to avoid defaunation or promote faunal recovery. The changes in mean seed width suggest larger vertebrates hold especially important functional roles in these human‐modified forests. Monitoring fruit and seed traits can provide a valuable indicator of ecosystem condition, emphasizing the importance of developing a comprehensive plant traits database for the Amazon and other biomes.

中文翻译：

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人工改良亚马逊森林中植物扩散模式和种子性状的大规模评估

1. 量化栖息地干扰对生态系统功能的影响对于理解和预测热带森林的未来至关重要。许多研究检查了与植物相互影响相关的动物性状的干扰后变化，但是干扰对不同森林中植物性状的影响受到的关注较少。
2. 针对巴西东部亚马逊地区的两个研究区域，我们使用了基于特征的方法来研究热带植物群落中种子传播功能如何在人类修饰的景观尺度梯度上发生变化，包括再生次生林和受燃烧影响的原始森林和选择性日志记录。
3. 对230个森林地块的调查记录了846种树种的26533根活茎。利用植物标本室的材料和文献，我们针对每种树种收集了性状信息，重点在于传播方式和种子大小。
4. 干扰减少了研究区的树木多样性，并增加了较低的木材密度和小种子树种的比例。干扰还增加了动物摄入的带有种子的茎的比例，并减少了其他机制（例如风）分散的茎的比例。较老的次生林在功能上与受灾最严重的原始林相似。对于每一个样地，平均种子大小和木材密度与植物物种与动物摄入的种子呈正相关。
5. 综合。人为干扰对树木群落的种子性状有重大影响，并与动物相互影响。动物介导的种子传播在受干扰和正在恢复的森林中发挥着重要作用，这凸显了避免毁林或促进动物恢复的需要。平均种子宽度的变化表明，较大的脊椎动物在这些人为改造的森林中起着特别重要的功能作用。监测水果和种子的性状可以提供生态系统状况的重要指标，强调为亚马逊和其他生物群落开发一个全面的植物性状数据库的重要性。