Menezes Luciana S, Müller Sandra C, Overbeck Gerhard E
Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
An Acad Bras Cienc. 2015 Oct-Dec;87(4):2081-90. doi: 10.1590/0001-3765201520140555. Epub 2015 Nov 27.
The natural vegetation of Southern Brazil's coastal region includes grasslands formations that are poorly considered in conservation policy, due to the lack of knowledge about these systems. This study reports results from a regional-scale survey of coastal grasslands vegetation along a 536 km gradient on southern Brazil. We sampled 16 sites along the coastal plain with 15 plots (1 m²) per site. All sites were grazed by cattle. We estimated plant species cover, vegetation height, percentage of bare soil, litter and manure, and classified species according to their growth forms. We found 221 species, 14 of them exotic and two threatened. The prostate grasses: Axonopus aff.affinis, Paspalum notatum and P. pumilumwere among the most important species. Prostrate graminoids species represented the most important vegetation cover, followed by cespitose grasses. Vegetation height, bare soil, litter and manure were similar among all areas, highlighting the homogeneity of sampling sites due to similar management. In comparison to other grasslands formations in Southern Brazil, the coastal grasslands presented rather low species richness. The presence of high values for bare soil at all sampling sites indicates the need to discuss management practices in the region, especially with regard to the intensity of livestock grazing.
巴西南部沿海地区的自然植被包括草原群落,但由于对这些系统缺乏了解,它们在保护政策中未得到充分重视。本研究报告了巴西南部沿海草原植被沿536公里梯度进行的区域尺度调查结果。我们在沿海平原上选取了16个地点,每个地点设置15个样地(1平方米)。所有地点都有牛群放牧。我们估计了植物物种盖度、植被高度、裸土、凋落物和粪便的百分比,并根据生长形式对物种进行了分类。我们发现了221个物种,其中14个是外来物种,2个是受威胁物种。匍匐草本植物:近缘地毯草、巴伊亚雀稗和矮雀稗是最重要的物种之一。匍匐类禾本科植物构成了最重要的植被覆盖,其次是丛生禾本科植物。所有区域的植被高度、裸土、凋落物和粪便情况相似,这突出了由于管理方式相似导致采样地点的同质性。与巴西南部的其他草原群落相比,沿海草原的物种丰富度较低。所有采样地点的裸土比例都很高,这表明有必要讨论该地区的管理措施,特别是关于牲畜放牧强度的问题。