Altitude-related changes in the mesofauna structure in soils of the Ethiopian plateau

Abstract

Ecological-faunistic investigations of the mesofauna were carried out in mountain soils of Ethiopia for the first time. A comparative assessment of the group composition and the structural parameters of soil invertebrate communities was accomplished in a series of mountain habitats on the slopes of an extinct volcano in the altitude range of 1800 to 3200 m a.s.l. Some regularities of the altitudinal changes in the abundance of invertebrates were found: a maximum in a forest on the volcano slope, a trend of reducing their number and mass with altitude, and the minimal abundance of invertebrates in the soils under the forest and on the slope of the volcano crater. In contrast to the mountain systems of southern Europe and Asia, the animal population on the Ethiopian Plateau in the lower positions of the mountain catena was dominated by the forms dwelling on the soil surface; in the forest belt and high mountains, the inhabitants of mineral horizons prevailed. Specific features of the functional structure of the animal population in the soil under the crater forest are its relations to open habitats. At the same time, the absence of faunistic exchange with the adjacent ecosystem of the alpine meadow allows suggesting that the soil animal communities in the crater and on the external volcano slopes were formed independently from one another.