Macroinvertebrates play a unique role in aquatic ecosystems by acting as processors of nutrients and organic energy from allochthonous and autochthonous sources. Within East Africa, and especially Kenya, anthropogenic influences on streams and rivers as a result of deforestation and the expansion of agricultural lands are pervasive. This study investigated land use v. altitudinal shifts in the functional composition of macroinvertebrates within the Mount Elgon catchment in western Kenya. A total of 20 sampling sites in 12 streams, 10 sites each within forested and agricultural areas, located in 3 elevation categories were sampled for physicochemical water parameters and macroinvertebrates. Significant (P < 0.05) spatial variation was observed in total suspended solids, coarse particulate organic matter, temperature and electrical conductivity between forested and agricultural sites. Shredder biomass and abundance was higher in forested streams at higher elevations. There was a significant increase in the abundance (of shredders, predators, collector filterers and gatherers), taxon richness (of shredders, predators and scrapers) and biomass (of shredders, collector filterers and gatherers) of functional feeding groups with increasing elevation. Data of near-natural sites are urgently needed to disentangle altitude and land use influences on the diversity and composition of aquatic communities in high-elevation streams in the tropics.

大型无脊椎动物作为来自外来和本土来源的营养物质和有机能量的处理器，在水生生态系统中发挥着独特的作用。在东非，尤其是肯尼亚，由于森林砍伐和农业用地扩张，人为对溪流和河流的影响无处不在。本研究探讨土地利用诉肯尼亚西部的埃尔贡山流域内大型无脊椎动物的功能组成的海拔变化。总共在 12 条河流中的 20 个采样点，森林和农业区各有 10 个采样点，位于 3 个海拔类别，对物理化学水参数和大型无脊椎动物进行了采样。显着 ( P < 0.05) 在森林和农业地点之间观察到总悬浮固体、粗颗粒有机物、温度和电导率的空间变化。在海拔较高的森林溪流中，粉碎机的生物量和丰度更高。随着海拔的增加，功能性摄食群体的丰度（碎肉机、捕食者、捕食者过滤器和采集者）、分类群丰富度（碎屑者、捕食者和刮刀者）和生物量（粉碎者、捕食者过滤者和采集者）显着增加。迫切需要近自然地点的数据来解开海拔和土地利用对热带高海拔溪流中水生群落多样性和组成的影响。