Vascular epiphyte biomass in a South Brazilian fragment of Atlantic Forest

Abstract The present study aimed at sampling the biomass of vascular epiphytes within a protected area in South Brazilian Atlantic Forest. All tree specimens with diameter at breast height equal or greater than 4.8 cm were measured and divided into classes. In each class, 10% of tree specimens were randomly selected for epiphytic biomass measuring. Furthermore, we divided the phorophytes into five tree parts to analyze epiphytic biomass. We generated mathematical models to estimate epiphytic biomass in similar forest areas. We analyzed 55 phorophytes and found an estimated epiphytic biomass of 5.3 Mg/ha. Epiphytic biomass ranged from 0.02 to 135 kg and the lower values were found on small-sized phorophytes. Higher values of epiphytic biomass were found on phorophytes with diameter at breast height between 30 and 36.5 cm. The tree part with higher epiphytic biomass was the outer crown. The epiphytic biomass showed a high correlation with phorophyte diameter, according to the mathematical models. We selected two equations which presented the most similar values to the ones we measured. Our results corroborate that epiphytes play a very important role as to the biomass level within tropical forests.

摘要：本研究旨在对巴西南部大西洋森林保护区内的维管附生植物（vascular epiphytes）生物量开展采样工作。所有胸径（diameter at breast height）不小于4.8 cm的树木个体均被测量，并划分至不同径级。在每个径级中，随机选取10%的树木个体用于附生植物生物量测定。此外，我们将附生宿主树木（phorophytes）划分为5个树木部位，以开展附生植物生物量分析。我们构建了数学模型，用于估算同类森林区域的附生植物生物量。本研究共分析了55株附生宿主树木，估算得到的附生植物生物量为5.3 Mg/ha。附生植物生物量区间为0.02~135 kg，较低的生物量值多出现于小型附生宿主树木。胸径介于30~36.5 cm之间的附生宿主树木，其附生植物生物量更高。附生植物生物量最高的树木部位为树冠外层。根据数学模型结果，附生植物生物量与附生宿主树木胸径呈高度相关性。我们选取了两个与实测值最为接近的方程。本研究结果证实，附生植物在热带森林的生物量组成中发挥着极为重要的作用。