Cunha N L, Delatorre M, Rodrigues R B, Vidotto C, Gonçalves F, Scremin-Dias E, Damasceno-Júnior G, Pott V J, Pott A
Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil.
Braz J Biol. 2012 Aug;72(3):519-31. doi: 10.1590/s1519-69842012000300015.
Studies on Neotropical aquatic macrophytes have increased in recent decades, however species richness in wetlands of South America is far from being fully known. In addition, studies having an ecological approach are scarce in the Pantanal. Rapid assessments are essential for gaining knowledge of the biodiversity in the region. This study was performed in five sites of the Baía do Castelo, the western border of the Brazilian Pantanal, which included wild-rice patches, floating mats and floating meadows. At each site, plots of 0.5 × 0.5 m were set (n = 137), species of aquatic macrophytes were identified, their coverage was measured and the plot depth was estimated. We recorded 57 species in 26 families, of which Poaceae was the richest. The most frequent and abundant species was Commelina schomburgkiana; the second most frequent was Oryza latifolia,followed by Leersia hexandra, Enydra radicans and Pityrogramma calomelanos. The latter species was second in cover, followed by Pontederia rotundifolia, Eichhornia azurea, E. crassipes and Enydra radicans. These five species and C. schomburgkiana (the most abundant) together represent more than half of the coverage on the lake. Pontederia rotundifolia, Ludwigia helminthorrhiza, Pistia stratiotes, E. azurea, E. crassipes, Enydra radicans and Panicum elephantipes were strongly associated with deeper areas, while Oryza latifolia, Leersia hexandra and Salvinia auriculata were prevalent in shallow areas. Pityrogramma calomelanos, Ludwigia nervosa, Ipomoea alba, Cayaponia podantha, Polygonum acuminatum, Rhynchanthera novemnervia and Ludwigia leptocarpa were highly correlated with floating meadows. The structure of the habitat, natural dynamics and zonation of aquatic vegetation in the Baía do Castelo seems to be influenced by a variation in water levels, which promotes spatial segregation, most likely due to competition and/habitat preference.
近几十年来，对新热带地区水生大型植物的研究有所增加，然而南美洲湿地的物种丰富度远未完全为人所知。此外，潘塔纳尔湿地采用生态学方法的研究很少。快速评估对于了解该地区的生物多样性至关重要。本研究在巴西潘塔纳尔湿地西部边界的卡斯特洛湾的五个地点进行，这些地点包括野生稻斑块、漂浮草甸和漂浮草地。在每个地点设置了0.5×0.5米的样方（n = 137），鉴定了水生大型植物的物种，测量了它们的覆盖度，并估算了样方深度。我们记录了26科的57种植物，其中禾本科最为丰富。最常见且数量最多的物种是肖氏鸭跖草；第二常见的是阔叶稻，其次是六蕊稗、水生菊芹和美叶蕨。后一种植物在覆盖度上排名第二，其次是圆叶梭鱼草、蓝花凤眼莲、凤眼莲和水生菊芹。这五个物种和肖氏鸭跖草（数量最多的）一起占湖泊覆盖度的一半以上。圆叶梭鱼草、柳叶丁香蓼、大薸、蓝花凤眼莲、凤眼莲、水生菊芹和象草与较深区域密切相关，而阔叶稻、六蕊稗和耳状槐叶萍在浅水区较为常见。美叶蕨、多脉丁香蓼、白牵牛、波丹瓜叶薯、尖叶蓼、九脉翼萼茶和细果丁香蓼与漂浮草地高度相关。卡斯特洛湾水生植被的栖息地结构、自然动态和分区似乎受到水位变化的影响，水位变化促进了空间隔离，这很可能是由于竞争和/或栖息地偏好所致。
