Efeitos da paisagem e solo sobre atributos funcionais foliares de espécies da vegetação ciliar em áreas com múltiplos impactos ambientais.

Abstract

Tropical forests represent the most biodiverse ecosystems in the world, however, these ecosystems suffer due to numerous environmental impacts. Among the impacts, the influence of human activities linked to mining in the Amazon has caused changes in watercourses and can alter the soil around them. Besides that, the landscape is increasingly fragmented. Thus, these changes can affect the functioning of natural ecosystems and alter the availability of resources for plants (e.g. light, water, and ions in the soil), which can affect the characteristics or functional traits of plants. Functional traits are characteristics capable of revealing how plants use resources. Therefore, the objective of the work was to evaluated: i) the soils of the studied forest fragments present variations in their chemical and physical characteristics; ii) the availability of nutrients in the soil and changes in the landscape influence the functional characteristics of the species and which variables most influence the traits; iii) species from different functional groups respond differently to possible changes in the environment. The study was carried out in 13 areas located in the municipality of Barcarena, Pará, Brazil. The species studied were: Bactris hirta palm (Arecaceae), herbaceous tree, Calathea altissima (Maranthaceae), and liana Tetracera sp. (Dilleniaceae). To answer the proposed objectives, we collected three individuals in each area and measured their leaf traits, namely, leaf area (LA), specific leaf area (SLA), and content of dry matter contained (LDMC). We also measured the integrative traits of leaf functioning, such as osmotic potential at the maximum turgor ( sFT), turgor loss point ( TLP), and modulus of elasticity ( ). The studied fragments showed a high degree of homogeneity in the chemical and physical characteristics of the soil and the landscape, indicative that there is not a significant gradient in the availability of resources in these areas. The traits of the plants responded to the edaphic factors and the changes in the landscape, in which, both the morphological traits and the integrators were more related to the chemical factors of the soil and the landscape. The species showed a similar variation for leaf morphological traits. However, for the traits from pressure-volume curves (integrative of leaf functioning), the herbaceous species and the palm showed greater intraspecific variation when compared to liana, which may be an indicative of a greater capacity to respond to environmental changes in these species. This study contributes to the knowledge about the functional traits of plants and how they relate to the environment since there are variations in the morphological and integrating trais that can indicate small changes in the evaluated ecosystems.