Most tropical forests are threatened by a myriad of human-induced disturbances, associated with land use changes, altered fire regimes and direct deforestation. The combined effect of multiple disturbances can shift forests towards a new, resilient state that is qualitatively distinct in structure, species composition and function. We found that abandoned pastures affected by fires in the Brazilian Atlantic forest showed similarity in terms of vegetation structure and plant functional traits to a savanna-like ecosystem. Burned communities exhibited more C₄ grass cover, higher proportion of resprouts and lower canopy cover as compared to the old-growth forest. Moreover, 79% of woody species at the burned sites are generalists with a widespread distribution, which includes the cerrado (Brazilian savanna). Woody species composition was strikingly different from old-growth forests, since burned sites were dominated by Moquiniastrum polymorphum (Less.) G. Sancho (Asteraceae), a fire-resistant species with a ruderal behavior that was absent in the old-growth forests. The results observed in this study provide biological evidence for an arrested succession with the establishment of a savanna-like ecosystem as an alternative stable state. These findings reinforce the notion that the establishment of an alternative stable state (e.g., savanna-like state) hypothesis for the Brazilian Atlantic Forest should be considered, especially under the current climate change scenarios.

大多数热带森林都受到无数人为干扰的威胁，这些干扰与土地用途的变化，火灾状况的改变和森林的直接砍伐有关。多种干扰的综合作用可使森林向新的，有复原力的状态转变，这种状态在结构，物种组成和功能上质的不同。我们发现，在巴西大西洋森林中受大火影响的废弃草场在植被结构和植物功能性状方面均与热带稀树草原相似。被烧毁的社区表现出更多的C ₄与旧林相比，草木覆盖率高，新芽率高，树冠覆盖率低。此外，被烧地点的木本物种中有79％是通才，分布广泛，其中包括cerrado（巴西大草原）。木本植物的成分与古老的森林显着不同，因为被烧毁的地方主要是多形莫桑木（较少）G. Sancho（菊科），一种耐火种，具目行为，在旧的森林中不存在。在这项研究中观察到的结果为建立类似热带稀树草原的生态系统作为另一种稳定状态提供了被捕接续的生物学证据。这些发现强化了这样一种观念，即应该考虑为巴西大西洋森林建立替代的稳定状态（例如热带稀树草原状态）假说，尤其是在当前的气候变化情景下。