Within an agricultural landscape, there are natural areas that serve important functions in the agroecosystem whilst providing a safe refuge for indigenous plant and animal species. An important tool that farmers can use to assist with the protection of these remaining natural areas is the usage of buffer zones of indigenous vegetation. Buffer zones are areas of land that are maintained next to or around sensitive, natural ecosystems to protect them against harmful impacts – these natural ecosystems can include rivers, streams, wetlands, and threatened vegetation types.
The implementation of buffer zones of indigenous vegetation in an agricultural landscape is known to have many benefits, including:
- Slowing of surface run-off which therefore reduces soil erosion risks;
- Stabilizing of embankments and mitigation against the impact of flooding events;
- Filtering out and reducing fertilizer and pesticide leakage from nearby cropland;
- Improving water quality through filtration by indigenous, aquatic plants;
- Providing a vital habitat for indigenous plant and animal species (including pollinators);
- Assisting as a biodiversity corridor for animals to move between protected areas and across the agricultural landscape.
For river ecosystems, the size of buffer zones will depend on the size and characteristics of the river, but a general minimum requirement is up to the 1:20-year flood line and as high as the 1:100-year flood line.
Once implemented, buffer zones should be maintained to ensure they function at their full potential. Threats to buffer zones, such as encroachment from Invasive Alien Plants (IAPs), cropland expansion, and irresponsible agrochemical applications, should be continuously mitigated.
The SIZA Environmental Standard encourages members to implement and maintain buffer zones under the following code requirements:
Code requirement 2.1
Production, packing, and processing activities do not impact the surrounding natural areas.
- Buffer zones are established, maintained, and conserved adjacent to all natural and protected areas to prevent contamination and protect wildlife habitats.
Code requirement 2.3
Production activities, processes, and infrastructure do not result in any contamination or degradation of water resources above or below ground.
- Measures are taken to establish and conserve buffer zones adjacent to all water sources to control pollution, prevent erosion, and protect wildlife habitats.
The successful implementation of buffer zones can be measured by checking the following:
1) the existence of buffer zones around natural ecosystems and water sources,
2) the size of each buffer zone and
3) the state of each buffer zone (e.g. presence/absence of IAP species).
Through the successful implementation and protection of buffer zones (and the natural ecosystems therein), farmers can maximise the full potential of natural areas occurring on their land, benefiting not just their own farm, but also their surrounding community and region as a whole.