Effects of sugarcane cultivation on benthic macroinvertebrate assemblages in tropical streams

Tropical streams support a diverse array of benthic macroinvertebrates, which play a crucial role in ecological processes and serve as bioindicators of ecosystem health. However, human-induced disturbances, particularly land use changes, can negatively affect stream structure and function. This study investigated how sugarcane cultivation influences benthic macroinvertebrate communities by comparing streams in sugarcane-dominated landscapes with those surrounded by native vegetation. The first hypothesis proposed that sugarcane plantations would lead to a decline in both taxonomic and functional diversity. The findings partially supported this, indicating that streams in sugarcane areas had lower abundance, taxonomic richness, and diversity, while functional diversity remained unaffected. In contrast, streams with native vegetation exhibited higher macroinvertebrate abundance, reinforcing their ecological importance. The second hypothesis suggested that seasonality would have a stronger influence on taxonomic composition in sugarcane streams due to variations in hydrological patterns. The results confirmed this, showing pronounced seasonal changes in taxonomic composition, especially during the rainy season. These findings underscore the significant effects of sugarcane cultivation on aquatic ecosystems and benthic macroinvertebrate communities. Ongoing monitoring of aquatic organisms in agricultural landscapes is crucial for assessing environmental impacts and guiding conservation efforts.

热带溪流栖息着种类繁多的底栖大型无脊椎动物（benthic macroinvertebrates），这类生物在生态过程中发挥关键作用，同时可作为生态系统健康的生物指示物（bioindicators）。然而人为干扰，尤其是土地利用变化，会对溪流的结构与功能产生负面影响。本研究通过对比甘蔗主导景观与原生植被环绕的溪流，探究了甘蔗种植对底栖大型无脊椎动物群落的影响。第一项假说提出，甘蔗种植园会导致分类学多样性（taxonomic diversity）与功能多样性（functional diversity）均出现下降。研究结果部分支持该假说：甘蔗种植区域内的溪流，其个体丰度、分类学丰富度（taxonomic richness）及多样性均更低，但功能多样性未受显著影响。与之形成对比的是，原生植被环绕的溪流拥有更高的无脊椎动物丰度，进一步印证了原生植被的生态重要性。第二项假说指出，受水文格局变化影响，季节性变化对甘蔗种植区溪流的分类学群落组成具有更强的调控作用。研究结果证实了这一推测：分类学群落组成存在显著的季节波动，尤以雨季最为明显。本研究结果凸显了甘蔗种植对水生生态系统及底栖大型无脊椎动物群落的显著影响。对农业景观中的水生生物开展持续监测，对于评估环境影响、指导保护工作具有至关重要的意义。