Estratégias morfoanatômicas foliares associadas à deciduidade em espécies predominantes do carrasco

Abstract

The Caatinga is one of the Seasonally Dry Tropical Forests (SDTFs), characterized by a high degree of endemism, irregular rainfall with long dry periods, and high temperatures. Carrasco is a vegetation type occurring on sedimentary formations within this domain and is characterized by dense, deciduous, non-spiny shrub vegetation with thin branches, in addition to occurring on soils with low fertility and low water retention. The aim of this study is to investigate foliar morphoanatomical variations in species predominant in carrasco vegetation, seeking to identify structural attributes that may be associated with tolerance to water stress, as well as the correlation of these attributes with leaf deciduousness. The study was carried out in the Reserva Particular do Patrimônio (RPPN) Serra das Almas, on the leeward side of the Ibiapaba Plateau, in a one-hectare plot within the carrasco phytophysiognomy. Leaf samples were collected from ten species, representing 85% of the importance value of the studied area, and were used for morphoanatomical and histochemical analyses. Additionally, functional traits were obtained from the DryFlor database, and the phenological characterization of the species was performed based on field observations and consultation of specialized literature. Anatomical results showed the presence of mucilage in the epidermis among species, as well as the occurrence of bundle sheath extensions, in addition to leaf thickness, epidermis, and cuticle with lower thickness when compared to evergreen species. From the statistical analyses, the results showed significant differences in the correlations between LMA and P and N, as well as between SD and LT among species. The PCA did not show significant results between phenology and functional traits, although it demonstrated a spatial trend among early- and late-deciduous species. Thus, it was possible to observe foliar anatomical strategies among deciduous species that enable them to persist in environments with high water stress. In addition, it was possible to observe that there is a tendency toward both acquisitive and structural strategies among carrasco species. Therefore, further studies are necessary to deepen the understanding of the relationship between phenology and functional traits within carrasco areas.