By Aziza Atieno

Swidden agriculture, commonly known as slash and burn agriculture, affects ant species variety in the degraded land, a new study reveals.

According to the study by Dr Elizabeth Finch,a Scientist at the Centre for Agriculture and Bioscience International (CABI), degradation due to swidden agriculture leads to a reduction in native ant species diversity and an increase in introduced ant species diversity. There were also correlated community compositional changes in both native and introduced species.

The study finds that during swidden, after harvesting, the land is left fallow and native vegetation regrows. The changes in the habitat structure due to agriculture modifies the ant community composition as different species will be favored in different habitats.

The effect of the structure habitat depends on the extent of the disturbance, where more structurally complex habitats provide more ecological niches, and a wider variety of food resources resulting in a higher species diversity than is found in less structurally complex habitats, the study adds.

The scientists, including those from the Madagascar Biodiversity CentreBangor University, Wales, University College Dublin and the California Academy of Sciences, found that in general, predatory species were the most likely to be negatively affected by swidden, whilst omnivorous species were the most likely to benefit from this form of agriculture.

Dr Finch added, “We found that closed canopy forests had the highest ant species diversity and were compositionally unique. This underlines the importance of their conservation. However, we also found that the less degraded swidden habitats harboured unique and native ant species. We recommend that if these habitats are used sustainably, with long fallows to avoid the degradation spiral, these could still play an important role in biodiversity conservation in swidden landscapes across the tropics.

“We need to find a way to increase in crop yields to relieve pressure sufficiently so that longer, sustainable, fallows may be achieved. Swidden systems have demonstrated capacity to maintain and even enhance carbon stocks. REDD+, a United Nations-backed framework that aims to curb climate change by stopping deforestation, could, therefore, potentially bridge the economic gap that is critical to ensure the sustainable implementation of such measures.”