Efeito da disponibilidade de recursos do ambiente na variabilidade intraespecífica do cipó Banisteriopsis caapi

Abstract

The vine species Banisteriopsis caapi (Spruce ex Gisebach) Morton, Malpighiaceae, is extremely variable in its morphological and chemical characteristics, which could be due to a tradeoff between resource allocation for growth or defense. We investigated how environmental resource availability may influence intraspecific variation of morphophysiological characteristics of B. caapi. In 12 locations in the western Amazon, 26 leaf and wood morphophysiological characteristics were measured in 53 adult plants (1-5 plants/site). Water, light and nutrient availability were estimated for each site through maximum climatological water deficit (MCWD), incident radiation (IR) and the sum of exchangeable bases (SB), respectively. We ran a principal component analysis (PCA) with the measured traits. PCA axis 1 explained ~ 45 % of morphophysiological characteristics’ variation, revealing a spectrum of investments in resource acquisition associated with defense strategies. Variations in this spectrum were associated with the resource gradient, especially with SB and MCWD. On the one hand, in areas with low SB, relatively higher MCWD (low water deficit) and high IR the plants presented traits associated with slow growth and less mobile chemical defenses. On the other hand, in areas with high SB, relatively low MCWD (higher water deficit) and low IR the plants presented traits associated with fast growth, higher water-loss regulation and mobile and induced defenses. The variation in morphological and chemical characteristics of B. caapi is associated with environmental conditions that vary regionally. The knowledge of these relationships contributes to predictions of how B. caapi vine may respond to climate change and to management and conservation strategies for this species.