Introduction: Seasonally flooded and terra firme forests are characteristic ecosystems of the colombian Orinoquia and of great importance in the maintenance of regional biodiversity and ecosystem functions. These forests have a unimodal precipitation regime that can cause a temporal division effect on the seedling regeneration niche. This could explain the high diversity and coexistence of plant species in these forests, as well as the compositional affinity between adults and seedlings, reinforcing the assembly of the community in mature forests. Objective: To evaluate the effect of flooding and rains on the dissimilarity and compositional affinity between adults and seedlings of a seasonally flooded and terra firme forests. Methods: We characterized the adult community of these forests in San Martín (Meta, Colombia) and compared it with their respective seedling communities before and after the flooding and rainy season, using Bray-Curtis dissimilarity and NMDS analysis. Results: We found that after flooding, compositional dissimilarity of the seasonally inundated forest decreased significantly between adults and seedlings, while their affinity increased significantly; however, this pattern was not as conclusive in the terra firme forest. Conclusions: These results indicate that seasonal flooding can cause temporary division in the seedling niche. However, it is important to consider the role of edaphic variables, which can be affected by floods and rains. Our results can contribute valuable information for the effective development of assisted restoration and conservation programs.
