Response of vegetation to sheep dung addition in a degraded Cerrado area

ABSTRACT Cerrado is the second largest biome in Brazil and is classified as a biodiversity hotspot. The establishment of hydroelectric power stations in Brazil originated degraded areas due to the removal of soil for construction of dams, in which native vegetation sometimes fails to reestablish due to the bad soil conditions. Sheep excrete most of the nutrients they ingest, such as phosphorus, calcium, potassium and nitrogen. This study aimed at investigating whether sheep dung contributes to the improvement of soil quality and stimulates the process of ecological succession in areas affected by the construction of the hydroelectric power station of Ilha Solteira. Four areas were selected, located at the Experimental Farm of Unesp Ilha Solteira/SP, and ten plots of 1 m2 each were established. From October 2014 to December 2015, five replicates received 150 g fresh sheep dung every 15 days. In December 2015 soil sample from top 0.10 m was collected for the determination of soil attributes. Aboveground biomass was also collected, separated into four functional groups, oven-dried and weighed. Data were analysed to check the effect of dung addition upon soil and vegetation variables. Dung addition stimulated the development of several functional groups and changed soil nutrient concentrations in all four studied areas.

摘要：塞拉多（Cerrado）是巴西第二大生物群系，被列为生物多样性热点地区。巴西水电站的建设因大坝施工过程中的土壤剥离产生了退化区域，这类区域因土壤条件恶劣，本土植被往往难以自然恢复。绵羊可将摄入的大部分营养物质（如磷、钙、钾与氮）排出体外。本研究旨在探究羊粪是否能够改善土壤质量，并促进伊尔索尔特雷拉（Ilha Solteira）水电站建设影响区域内的生态演替过程。研究选取了位于圣保罗州伊尔索尔特雷拉市圣保罗州立大学（Unesp）实验农场的4处区域，设置了10个面积为1平方米的样地。2014年10月至2015年12月期间，5个重复样地每15天施加150克新鲜羊粪。2015年12月，采集0-10cm表层土壤样本以测定土壤属性。同时采集地上生物量，将其划分为4个功能类群，经恒温烘干后称重。通过数据分析验证羊粪施加对土壤及植被变量的影响效应。羊粪施加可促进多个功能类群的生长，并改变了全部4处研究区域的土壤养分浓度。