Stream running through subtropical mountain forest of Nepal. The stream bottom has a characteristic composition of bedrock, bolders and pebbles due to discharge and slope. The wide streambed is well lit by direct sunlight leading to proliferation of algae and rooted water plant. The diurnal and annual ranges of water temperatures show characteristic courses. Finally a typical aquatic macroinvertebrate community will inhabitat this stream type.
Photo: S. Sharma

In alpine regions the rivers have much colder water temperatures which begin to warm up for a short period after the disappearance of the ice-cover in late spring-early summer. Especially rivers that originate from the melting of glaciers have extremely cold temperature, near freezing, year round. The cold temperatures lead to depleted aquatic macroinvertebrates communities that are highly restricted in diversity.
Photo: K.L. Raptel