Impact of Domestic Animals on Ecosystem Integrity of Lesotho High Altitude Peatlands

Abstract

Wetlands are considered ecologically sensitive ecosystems with unique habitats for a great variety of plants species, birds, small mammals and other aquatic organisms. The term “wetland” is used to describe various habitats where the soil is wet for extended periods of the year but not necessarily permanently waterlogged (Collins, 2005). Wetlands are formed where surface water collects or where ground-water seeps to the surface for long-enough periods to sustain vegetation typically adapted or tolerant of hydric soil conditions. Thus wetlands comprise a large variety of waterlogged habitats such as bogs, estuaries, fens, floodplains, marshes, peatlands, playas (pans), seeps, springs, and swamps located on various altitudes and topographical locations. In his book on wetlands of southern Africa, Cowan (1995) used the definition of a wetland as it is stated in Article 1.1 of the Ramsar Convention where it has been defined as: “areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres”. The South African National Water Act (Act 36 of 1998) defines wetlands as “land which is transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land periodically covered with shallow water, and which in normal circumstances support or would support vegetation typically adapted to life in saturated soil”. Peatlands are unique wetland ecosystems in terms of their species composition and age. The process of peat formation is very slow which means that some of these wetlands are ancient as they have a deep peat deposit of over two metres. Peat is organic soil material with a particularly high organic content which, depending on the definition, usually has at least 20% organic carbon by weight. Peatlands are wetlands in which peat (dead plant matter) accumulates due to slow decomposition (Cronk & Fennessy, 2001). These peatlands can be classified into two major types namely bogs and fens. The definition of a bog is, a peataccumulating wetland that has no significant water inflows or outflows and supports acidophilic mosses, particularly Sphagnum (usually acidic; pH 7)( Cronk & Fennessy, 2001; Mitch & Gosselink, 2000). According to these definitions, the high-altitude wetlands of Lesotho are therefore incorrectly classified as bogs by Grobbelaar & Stegman (1987), Herbst & Roberts