Blog

Agriculture, mining and wetlands interaction

http://www.grainsa.co.za/agriculture,-mining-and-wetlands-interaction

ALTHEA GRUNDLING, ARC-Institute for Soil, Climate and Water, Pretoria, South Africa, PIET-LOUIS GRUNDLING, Centre for Environmental Management, University of the Free State

Worldwide, food and water security has become a growing concern and population dynamics a reality. 2014 is the UN International Year of Family Farming – therefore the Ramsar Convention chose Wetlands & Agriculture as the World Wetlands Day theme for 2014, focussing on the past, present and future importance of wetlands as a critical agricultural natural resource. The important role that wetlands play in food and water security can thus not be ignored.

In South Africa, many communities rely on wetland environments for their livelihood: Providing fibre, protein, water and an agricultural resource (cultivation and grazing). This reliance on wetlands is expected to increase rather than decrease in both rural areas and those adjacent to impoverished urban communities.

It has been reported that the agricultural sector has been responsible for the destruction of wetland systems by draining, cultivation and overgrazing, often without applying any wise principles of use.

Another significant player within this scenario is the mining industry with its increasing impact on both high potential agricultural land and wetlands. The Department of Water Affairs and Forestry (DWAF, 2005) reported that in some catchments over 50% of the wetlands have been destroyed as the result of drainage of wetlands for crops and pastures, poorly managed burning and grazing and subsequent donga erosion, planting of alien trees in wetlands, mining and urban development.

The National Biodiversity Assessment 2011 Report (Driver et al., 2012) stated that 65% of wetland ecosystem types in South Africa are threatened, including 48% that are critically endangered, making wetlands the most threatened of all of South Africa’s ecosystems.

Agriculture and mining are regularly accused as culprits responsible for wetland degradation and loss. Against the background of the above and other reports, it seems evident that South Africa needs to not only determine and substantiate the nature and extent of agricultural impacts on wetlands and on how wetlands sustain related agriculture, but also to quantify these effects from a geographical and resource point of view.

Such evidence-based quantification and qualification should enable the much needed determination of expected agriculture and wetlands interactions in future and interventions to ensure balanced and sustainable practices.

Furthermore, the expected long-term impact of mining on agriculture needs to be defined. Wetlands are often hailed as one of the measures to rectify poor water quality discharge from mines. Herein might arise an opportunity to further both agricultural resources and wetland conservation.

Much needed interaction and awareness on key issues Wetlands and the functions of wetlands go beyond agriculture and mining to include a range of other ecological functions and socio-economic benefits. A balance is therefore needed between the supporting, regulating and cultural services of wetlands on the one hand and its provisional services which include the provision of food, water, fibre, medicine and fuel on the other hand. Establishing and maintaining this balance was the driving force behind the Agriculture, Mining and Wetlands Interaction Workshop that was recently held. The Water Research Commission in partnership with the ARC-Institute for Soil, Climate and Water and the South African Wetland Society hosted the Agriculture, Mining and Wetlands Interaction Workshop during the National Wetlands Indaba, 2014. The main aim of the workshop was to recommend short-, medium- and long-term research needs (Grundling, 2014).

Guest speakers introduced the discussion topics to address the workshop objectives:

• Wetland management legislation successes and challenges.
• To define the nature and quantify the current and likely future impacts of agriculture on wetland services.
• To define the nature and quantify the current and likely future impact of mining on agriculture and wetlands.
• To assess the development potential of wetland products through innovative applications, e.g. fibre products, medicinal applications and filtration/purification.

Discussion points Dr Wietsche Roets, from the Department of Water and Sanitation, addressed the participants on wetland policy, legislation and management and said that the Department of Water and Sanitation’s primary mandate is to manage, use, develop, protect, control and conserve South Africa’s water resources. Any activity that can potentially impact on these valuable and sensitive water resources must be properly regulated through the specified processes in the National Water Act.

Mr John Dini (South African National Biodiversity Institute, Ecological Infrastructure) highlighted the fact that wetland destruction is inevitable, as trade-offs continue to be made for the sake of development. Offsets provide a mechanism for compensating for the unavoidable residual loss of wetlands and the services they provide, once all options for avoiding and minimising impacts have been exhausted. The Department of Water and Sanitation is in the process of compiling a position paper on wetlands, a guideline on activities affecting wetlands, amending the wetland delineation guidelines and adopting the wetland buffer and wetland offset guidelines.

The latter provides methods and metrics for designing offsets that compensate adequately for impacts on wetlands as ecological infrastructure, biodiversity assets and providers of ecosystem services. Dini said that the intention is to adopt the offset guideline within the Department of Water and Sanitation to ensure that wetland offsets are applied in a consistent, predictable and acceptable manner.

Mr Francis Steyn (Western Cape Department of Agriculture Sustainable Resource Management: LandCare) reiterated the value of a healthy ecosystem using the Berg River Project case study. The project’s aim was to restore the important Berg River system and reduce flood risks.

This river supplies a major portion of the water for domestic purposes in the Cape Metro, 22 500 ha of irrigation for high value crops on 600 farm units along the Berg River system and a gross farm gate value of R911 million of which R642 million was from exports (2005 figures).

The agricultural activities provided 14 100 permanent and 16 500 temporary jobs during 2005. Presently this natural resource is in a degraded state and poses a major threat to human health (water and flooding) and a decline in the economy (loss of jobs and land because of flooding).

Dr Johan van der Waals (Terra Soil Science) took a closer look at the impact of mining on agriculture and wetlands. There are two different forms of mining, namely opencast coal mining and sand mining. Both have significant impacts on both agriculture and wetlands. Van der Waals’ presentation gave a good perspective on the above conflicts by clarifying hydropedology processes dominant in plinthic catena found in mining environments.

The plinthic horizon is often an indication of a fluctuating water table, critical to both agriculture and wetlands. For example, a plinthic horizon can act as a “reservoir” of water for crops during short and intense dry spells during the growing season. However, during high rainfall years the crops may drown. If the water table is close to the surface, it complies with the definition of a wetland according to South Africa’s National Water Act (Act 36 of 1998).

Dr Jan Sliva (Technische Universität München) gave a talk on “wetland agriculture”, the production of organic construction and insulation material from Typha (bullrush, cattail) biomass on communal rehabilitated and re-wetted wetlands.

Internationally, especially within the European Union, there is a paradigm shift from the destructive use of wetlands towards sustainable “wetland agriculture”. Paludiculture, for example, is a novel land-use practice recognised by leading international academic institutions and environmental agencies that might be more resilient under climate change (too much or too little rain).

In Europe, the biology, ecology and cropping requirements of Typha as well as the harvesting technologies and technology chains for the production of the construction materials (boards, panels, etc.) have been tested in large-scale, real-world experiments.

Furthermore, Typha is also suitable for waste water treatment, nutrient control and can be efficiently used as an easily affordable renewable biofuel. Participants received the “wetland agriculture” idea for application in the South African context with both enthusiasm and caution. Dr Sliva discussed the opportunities, changes, environmental and social impacts and implementation risks of this innovative Typha-based small-scale industry.

Critical questions During the workshops, participants listed critical questions for future research, such as:

• Can we qualify the nature and extent of the impact of agriculture on wetlands?
• Can we quantify the impact of agriculture on the regulating, supporting and cultural functions of wetlands?
• Can we geographically and resource-wise qualify and quantify the importance of the provisional service of wetlands at present and in future?
• Can we list and identify the gaps in and limitations of current ecosystem-specific agricultural wetland-interaction practices as well as limitations and challenges to ensure the dissemination and implementation of good practices?
• What studies and mechanisms are required to enable us to answer these questions?
• What is the impact of other activities in a wetland environment, for example mining, on agricultural-wetland-interaction? A Ramsar wetland has been monitored in the past to determine the effect of mining effluent on agricultural crops. Should such studies be pursued?

Conclusion Agriculture and mining with associated activities poses a real and significant risk to water resources, such as wetlands, as it changes the landscape and creates numerous new hydrological and water quality gradients.

It will be in the long-term interest of both these industries and the society in general, to adopt the wise use of wetland practices, to protect and improve this valuable natural resource and enhance the integrity of the landscape in which it is situated.

For reaction from the agricultural community on the main discussion points and critical questions or for general wetland enquiries, please contact Dr Althea Grundling at althea@arc.agric.za.

References

Driver, A., Sink, K.J., Nel, J.L., Holness, S., Van Niekerk, L., Daniels, F., Jonas, Z., Majiedt, P.A., Harris, L. & Maze, K. 2012 National Biodiversity Assessment 2011: An assessment of South Africa’s biodiversity and ecosystems. Synthesis Report. South African National Biodiversity Institute and Department of Environmental Affairs, Pretoria. Department of Water Affairs and Forestry (DWAF) 2005. A practical field procedure for identification and delineation of wetland and riparian areas. Department of Water Affairs and Forestry, Pretoria, South Africa. Grundling, A.T. 2014 Agriculture, mining and wetlands interaction workshop starter document. ARC-Institute for Soil, Climate and Water, Pretoria, South Africa. Report No. GW/A/2014/211. National Wetlands Indaba 2014 expanded provisional programme http://indaba2014.wetlands.za.net/programme.htm

Acknowledgements Acknowledgement is hereby given to the Water Research Commission, South African Wetland Society and the ARC-Institute for Soil, Climate and Water.