Epífitas vasculares necessitam de longos períodos para colonizar forófitos em florestas alagáveis de igapó na Amazônia Central

Vascular epiphytes play important ecological roles, such as providing shelter and food for various organisms, contributing to nutrient cycling, and serving as environmental bioindicators. Despite their importance, their ecology remains poorly studied, especially in floodplain environments such as igapó forests. It is known that characteristics of host trees (phorophytes), such as size and age, influence epiphyte richness and composition, with larger and older trees offering greater colonization area and longer exposure time to diaspores. Younger trees tend to present less structure and stability to support these plants. Measures such as diameter at breast height (DBH), height, and crown area have been widely used as proxies for colonization potential, but the actual age of the tree — a variable more directly related to exposure time — is rarely considered due to the complexity of its estimation. This study analyzed how tree age, the potential colonization period (PCP) — defined as the time required for a tree to grow above the maximum flood level and thus become effectively available for epiphytic colonization — DBH, diameter increment rate (DIR), and height influence the richness, abundance, and composition of vascular epiphytes in an igapó forest located in Jaú National Park, Central Amazonia. Trees of two species, Macrolobium acaciifolium and Hevea spruceana, with DBH ≥10 cm, were sampled, and all vascular epiphytes were identified and quantified. Sampling involved the use of a camera and binoculars, as well as climbing to access the canopy. Tree age was determined through growth ring analysis obtained with an increment borer, using the LINTAB system with 0.01 mm precision. A total of 759 epiphytic individuals were recorded, distributed among 29 species, 14 genera, and 7 families. Hevea spruceana presented ages ranging from 36 to 157 years, with epiphytic colonization beginning at 44 years. Macrolobium acaciifolium ranged from 47 to 190 years, with colonization starting at 52 years. Generalized Linear Models (GLMs) indicated that the model including PCP and DIR best explained the variation in epiphyte richness (D² = 35.8%) and abundance (D² = 49.1%) for M. acaciifolium. Similarly, the same predictors best explained the variation in richness (D² = 33.2%) and abundance (D² = 38%) for H. spruceana. The results highlight the long recovery time of epiphytic flora in igapó forests and reinforce that the conservation of large, old, and vigorously growing trees is essential for maintaining the diversity of vascular epiphytes in floodplain forests.