Hydric soils: A new dimension to stemming wetland degradation
By Botle Mapeshoane, National University of Lesotho, Soil Science and Resource Conservation Department
The state of global wetlands is generally deteriorating and the mountain wetland ecosystems of Lesotho are no different. Lesotho’s mountain ecosystem occupies the highest part of the Drakensberg Escarpment between 2400m and 3482m above sea level and are primarily used for summer grazing transhumance practices. These mountains, with unique wetlands, host regionally and globally significant plant and animal bio-diversity.
Climate change, characterised by rising temperatures and a greater frequency of droughts and extreme rain events, is negatively affecting local communities living in rural parts of Lesotho (Marake, 1999). The fragile mountain ecosystem of Lesotho provides a range of services that increase the resilience of these communities to the negative impacts of climate change. These include regulating services such as storing and retaining water. However, this ecosystem is characterized by widespread degradation as a result of unsustainable land management and exploitation of natural resources.
Lesotho’s mountain wetlands exhibit evidence of degradation, with gullies draining the wetlands due to soil erosion and increased grazing pressure. This results in loss of wetlands and ecosystem services translating to negative impacts on livelihoods that rely on natural resources. One important precursor to improving management and preventing degradation of the wetland ecosystem, is the ability to constantly monitor and evaluate its status.
Using hydric soil as signatures of wetland conditions is a new dimension to evaluating wetland ecosystem services. [Hydric soils are those that are permanently or seasonally saturated by water, resulting in anaerobic conditions which support hydrophytic vegetation, as found in wetlands].
Through extensive research on Lesotho mountain wetlands since 2009, the Department of Soil Science and Resource Conservation at the National University of Lesotho has built on vast datasets shared by the Ministry of Water and development projects such as Orange-Senqu River Commission (ORASECOM). The Department has duly established a course on hydric soil identification and wetland ecosystem services evaluation. So far, more than thirty graduates and four postgraduates have had first-hand experience in identifying hydric indicators and relating them to wetland ecosystem services.
The university has also carried out field days with government officials in the departments of Water Affairs and Rangelands to explore use of hydric soils in wetland monitoring. During these field days, participating officials classified soil pits along transects from a wetland to an upland area and identified hydric indicators. Based on the feedback from participants, the University, through support from RUFORUM, is guiding policy and management strategies for range and water resources.
Such competencies are needed to turn around the negative trends in wetland degradation. In the future, the university hopes to gear its course on hydric soils to suit not only non-soil scientists, but also the more experienced soil scientists in field of pedology. This mix of participants will present more opportunities for multi-disciplinary discussion and enhance the richness of the course.
 Marake M.V. 1999. Arable Agriculture in Lesotho. In First State of the Environment Report (ed.) K.Q. Chakela. 1999. National Environmental Secretariate. Government of Lesotho.