Allochthonous organic matter in low-order streams is, in general, mainly composed of senescent leaves. However, in tropical streams green leaves can represent an important source of energy. The present study evaluated the decomposition of green and senescent leaves in Amazonian streams using leaves of three plant species: Inga stipularis D.C. 1876, Tococa guianensis Aubl. 1775 and Vochysia ferruginea Mart. 1826. The leaves were incubated for 120 days in four streams in the municipality of Santarém in western Pará State, Brazil. Senescent leaves were collected using nylon nets suspended 1 m above the ground, while green leaves were collected manually, directly from the trees. Green leaves exhibited better nutritional status: higher values for nitrogen and phosphate and lower values for carbon. Toughness and percentages of tannin and lignin of the green and senescent leaves varied among the studied species. Mass loss of green leaves was ~ 3.5 times higher than that of senescent leaves after 120 days. Higher values of phosphate and nitrogen and lower values of carbon, tannin, and lignin in green leaves were fundamental in explaining the difference in decomposition between green and senescent leaves. These differences reinforce the importance of understanding the role of green leaves in aquatic environments.

通常，低序流中的异源有机物主要由衰老叶片组成。但是，在热带溪流中，绿叶可以代表重要的能量来源。本研究使用三种植物的叶片：Inga stipularis DC 1876，Tococa guianensis Aubl评估了亚马逊河中绿色和衰老叶片的分解。1775年和沃希西亚（Vuchysia ferruginea）市场。1826年。在巴西帕拉州西部的圣塔伦市，叶子在四股溪流中孵育了120天。使用悬挂在地面上方1 m的尼龙网收集衰老的叶子，而人工直接从树上收集绿色的叶子。绿叶表现出更好的营养状况：氮和磷的含量较高，而碳的含量较低。绿色和衰老叶片中单宁和木质素的韧性和百分比在所研究的物种之间有所不同。120天后，绿叶的质量损失比衰老叶高约3.5倍。绿叶中较高的磷酸盐和氮含量以及较低的碳，单宁和木质素含量是解释绿叶和衰老叶分解差异的根本原因。