Understanding the effects of disturbance on seed rain is critical to predict changes in forest species composition and diversity. Logging effects on seed rain in a mixed conifer-hardwood forest complex in southern Brazil were evaluated. One year of seed rain data were collected from a large-scale observational experiment in logged and protected forests and quantity and average seed size weighted by species abundance (CWM) were compared between old-growth and logged stands 55 years after logging activities. Using these data, variations in frequency of functional groups of species in the seed rain were examined to see if they could be attributed to logging. Results show that the number of seeds per trap was highly right-skewed, ranging from 13 to 12,788 seeds per trap in one year. Seed rain was affected by logging history, with seed traps in old-growth plots receiving significantly less seeds than traps in logged plots. All species included mean seed size weighted by species abundance were significantly smaller in logged than in old-growth forests. This difference persisted after the exclusion of Araucaria angustifolia, a large-seeded pioneer which was intensively logged, although the difference of seed size between the two forest classes was greatly reduced. Species abundance in the seed rain differed significantly from the established tree community, between logged and old-growth stands. The composition of the seed rain was much more variable than the composition of the established tree community and its points more scattered over the ordination space than the points corresponding to the protected forests. The number of collected seeds across different functional groups of species significantly differed between logged and old-growth plots. The seed rain of logged forests reflects their arrested succession as indicated by reduced abundance of functional groups such as pioneers, large seeded pioneers and Araucaria, as well as reduced functional diversity. Seed rain differences between logged and old- growth stands reflect the intensive logging of A. angustifolia.

了解干扰对种子雨的影响对于预测森林物种组成和多样性的变化至关重要。评估了巴西南部针叶-阔叶林混交林中伐木对种子雨的影响。采伐和防护林采伐活动55年后，从采伐和保护林中的大规模观察实验中收集了一年的种子雨数据，并比较了老龄林和采伐林分中按物种丰富度（CWM）加权的数量和平均种子大小。使用这些数据，检查了种子雨中物种功能组频率的变化，以查看它们是否可归因于伐木。结果表明，每个陷阱的种子数高度偏斜，一年中每个陷阱的种子数量从13到12,788不等。种子雨受到伐木历史的影响，在旧耕地中的种子陷阱比在伐木地中的种子陷阱少得多。包括所有物种在内的所有物种的平均种子大小（按物种丰富度加权）在伐木区要比旧林要小得多。排除以下因素后，这种差异仍然存在南洋杉（Araucaria angustifolia）是一个大种子的先驱，被密集采伐，尽管两个森林类别之间的种子大小差异大大减小了。种子雨中的物种丰度与既定的树种和旧的林分之间的树种群落差异很大。种子雨的组成比已建立的树木群落的组成变化多得多，其点在排序空间上比与保护林对应的点更分散。在伐木和旧土样地上，跨不同功能物种组收集的种子数量显着不同。砍伐森林的种子雨反映出其被捕的演替，如先锋队，大型种子先锋队和南洋杉等功能性团体数量减少所表明。以及减少的功能多样性。伐木和老龄林之间的种子雨差异反映了A. angustifolia的密集采伐。