State of the wetlands
Mondi, as a significant user of water, recognises the need to support and lead in measures to protect water resources, and, in particular, the precious wetland ecosystems that occur on company land. Mondi South Africa manages approximately 300,000 hectares, with about 200,000 hectares of this being commercial timber plantations.
The remaining 100,000 hectares of this land comprises unplanted areas, where a rich heritage of grasslands, indigenous forest and varying types of wetland and riparian zones can be found. The wetland area is estimated to be about 19,500 hectares. Some 66% of this falls in KwaZulu Natal and the remaining 34% in Mpumalanga.
In 2009, Mondi began a health assessment of its wetlands, with the aim of acquiring knowledge that would contribute to improved wetland management. In assessing the state of our wetlands, it is important to consider the history of the wetlands and the natural wet and dry hydrological cycles in South Africa. Many of our wetlands have been impacted by poor agricultural practices prior to afforestation, including overgrazing and indiscriminate burning of grasslands, soil erosion and drainage of wetlands for extended periods. Early plantation forestry practices encroached on wetland and riparian areas and, in some cases, dried up small streams, allowed uncontrolled alien invasive species to dominate wetland habitats and promoted annual burning of riparian areas for fire protection. Although commercial forestry plantation practices have improved substantially over the last two decades, many of our significant wetlands continue to be impacted by other land use practices in catchment areas.The results demonstrate significant improvements in wetland functions but clearly indicate where more effort is required to restore essential wetland ecosystem functions.
The four principal research objectives of the assessment were:
- to identify Mondi’s most important wetlands from a biodiversity conservation point of view
- to examine the present ecological state or “health” of a selection of wetlands
- to describe the type and extent of the ecosystem goods and services provided by a selection of wetlands
- to provide an overview of the major impacts of afforestation on wetlands - this data to be used to guide management of wetlands other than those assessed
Wetlands representing the full spectrum of Mondi’s land holdings were selected in an attempt to assess the impact of our management practices and other land-use activities on the wetlands. Altogether, fourteen wetland systems of varying type, size and location were assessed for the state of the wetlands report. The majority (57%) of the wetlands assessed were located within endangered vegetation areas while 36% were located in vulnerable vegetation areas. One wetland, Kwambonambi swamp forest, was located in a critically endangered vegetation area.
WET-Health, a technique for rapidly assessing wetland health, was used for the evaluations. WET-Health provides a health score for a wetland based on the weighted average of three components crucial to the ecological health of a wetland: hydrology, geomorphology and vegetation. WET-Health also provides a “trajectory of change” score, allowing an accurate prediction of how the wetland’s health will change over the next five years.
A health score was given to each selected wetland and threats that should be managed were identified. The most important identified impact on the wetlands was reduced water supply from the catchment area caused by afforestation and other land-use practices. Other management priorities identified during the study were invasive alien plants, fire management and grazing.
Following the health check, an assessment was made of ecosystem services delivered by each wetland, with WET-Ecoservices providing a rating of those services. Ecosystem services are classified into four different types:
- provisioning services refers to the provision of goods such as water, food and raw materials for supporting community livelihoods
- regulating services are processes that contribute to economic production or save costs, such as flow regulation (including flood attenuation and groundwater recharge), erosion control, water purification and carbon sequestration
- cultural services relate to ecosystem attributes and include the spiritual, educational, cultural and recreational services derived from the use or appreciation of biodiversity
- supporting services include such functions as biodiversity maintenance
The services provided by Mondi’s wetlands are in great demand and used extensively by local people. In several instances, people rely on wetland water for drinking and household purposes. The use of wetlands for food crop production is an important service in northern KwaZulu Natal and in southern Mpumalanga, where food gardens are commonly found within the wetlands assessed. Grazing of wetlands is an important service in 64% of the assessed wetlands. Research assigning rand values to wetland services has shown a real dependence by people on wetlands. Management practices need to balance the preservation of wetlands for biodiversity reasons with the community’s need for ecosystem services such as the supply of harvestable resources and food cultivation.
Based on the results of the state of the wetlands report, recommendations were made for each wetland to maintain or improve ecosystem services. Relevant practical management actions will be developed which will be incorporated into the overall management plan for each area.
Report results indicate that the assessed wetlands were either largely (50%) or moderately (43%) modified. Without specific mitigation measures, it was predicted that there would be little change in the health of Mondi wetlands over the next five years.
The most important impact on the wetlands assessed, in terms of its ubiquity and intensity of impact, was reduced water inputs to the wetland from the catchment caused by afforestation and other land-use activities in the catchment. Although these wetland catchments had similar extents of afforestation, the impact on the wetlands was variable. The hydrological impacts of afforestation are very difficult to assess and greatly influenced by the natural variability of rainfall and the strong occurrence of regular wet and dry cycles.
The highest management priorities identified during the study are control of invasive alien plants, fire management and controlled grazing. Fire and grazing are closely allied as fire is a tool used to promote tender grass growth.
|Management Region||Historic Landuse||Grazing pressure||Fire regime||Alien plants||Cultivation||Roads||Delineation|
|Zululand coastal||Sugar Cane||N/A|
|Northern KZN and southern Mpumalanga||Agriculture|
Management practices need to balance the preservation of these wetlands for the maintenance of biodiversity and the provision of ecosystem services such as harvestable resources and cultivated foods utilised by communities.
Chris Burchmore, forest environmental manager, Mondi South Africa, says, “By assessing the condition of these wetlands sampled in the state of the wetlands report, Mondi has improved its knowledge of these vital ecosystems and their services. This means that management plans can be improved to preserve our wetlands and ensure their services are available for future generations.”