When an area previously used for agricultural or sylvicultural purposes is abandoned, it may undergo natural regeneration. However, the outcome of such regeneration depends on a number of factors, including the presence of non-native invasive plants, and, when production forests such as eucalypt plantations are considered, remaining non-native trees may also affect the natural regeneration possibilities. We studied how remaining eucalypt trees affect woody species regeneration and invasive grasses in an abandoned Eucalyptus grandis plantation in a regenerating Brazilian savanna site. We sampled the woody vegetation and invasive grasses in 30 8 × 8-m plots and surveyed the eucalypt trees within these plots and in 3 m-wide strips around them. Eucalypts negatively affected the cover of the C4 invasive African grass Melinis minutiflora and the total abundance and basal area of native woody plants in general and of two dominant species, suggesting an overall negative effect on native plant regeneration notwithstanding the also negative effects on African grasses. Conversely, they had no effect on species richness, species diversity nor mean height of woody plant communities nor on the abundance of three other dominant native woody species. Interestingly, a low eucalypt abundance had small effects on native woody species but much stronger effects on the cover of M. minutiflora, possibly due to shading. Thus, our results indicate that remaining eucalypt trees may hamper the natural regeneration of native woody plants, but also suggest that maintaining a low density of eucalypt trees may be a cost-effective strategy, given the high costs associated with the complete removal of remaining trees and the difficulties in controlling invasions by African grasses.

当先前用于农业或园林目的的区域被废弃时，它可能会自然再生。但是，这种再生的结果取决于许多因素，包括是否存在非本地入侵植物，并且，当考虑到诸如桉树人工林等生产林时，剩余的非本地树木也可能影响自然再生的可能性。我们研究了剩余的桉树如何影响废弃的桉树中木本植物的再生和入侵草人工林在更新的巴西热带稀树草原上种植。我们在30个8×8-m的样地中采样了木质植被和侵入性草，并调查了这些样地内和周围3 m宽条带中的桉树。桉树对C4入侵非洲草Melinis minutiflora的覆盖率产生负面影响以及一般木本植物和两种优势种的天然木本植物的总丰度和基础面积，尽管对非洲草也有负面影响，但这表明对本地植物再生有总体负面影响。相反，它们对物种丰富度，物种多样性，木本植物群落的平均高度和其他三种主要的本地木本物种的丰度没有影响。有趣的是，低桉树的丰度对本地木本物种影响不大，但对小叶木兰的覆盖率影响更大。，可能是由于阴影。因此，我们的结果表明，剩余的桉树可能会阻碍本地木本植物的自然再生，但也表明，鉴于彻底清除剩余树木的高成本，保持低密度的桉树可能是一种具有成本效益的策略。以及控制非洲草入侵的困难。