Influência das características de caule no escoamento pelo tronco em espécies florestais de terra firme

Abstract

Stemflow (ETr) is a key hydrological process for the redistribution of precipitation within forest ecosystems. This study evaluated the influence of stem morphological traits and stem moisture on ETr in tree species from a terra firme forest in Amapá, Brazil. A total of 52 individuals were monitored, considering dendrometric variables (DBH, height, basal area, and crown area), morphological traits (bark texture and stem inclination), and environmental factors (precipitation, air humidity, and stem moisture). Stem moisture was measured using a digital penetration meter, allowing the correlation between water retention and stemflow volumes. On average, ETr accounted for 0.3% of total precipitation, a seemingly low percentage, yet relevant to hydrological dynamics. Trees with smooth bark showed the highest stemflow volumes, followed by those with rough bark, while scaly-barked individuals exhibited the lowest values. Stem moisture presented significant seasonal variation, showing an inverse relationship with ETr volumes during certain periods, highlighting the influence of both internal water status and atmospheric conditions on water conduction. Additionally, crown architecture favored water channeling, whereas larger diameters and stem inclination reduced process efficiency. It is concluded that, although representing a small fraction of precipitation, ETr is strongly conditioned by moisture and morphological attributes, playing an essential role in water redistribution in tropical terra firme forests.