Full paper: https://doi.org/10.1007/s10841-022-00410-6
Summary: In this paper, researchers compared the impact of Holistic Management to wildlife grazing on grass and ground dwelling beetle species diversity on neighboring farms in Namibian rangeland. The paper notes that despite rotational grazing, the typical form of management in southern Africa, land degradation is still seen in the form of bush encroachment. To resolve this, there has been a call for an adaptive grazing management strategy, i.e. Holistic Management, to restore these degraded rangelands and conserve biodiversity. Others advocate for natural wildlife management in the form of “conservancies,” requiring little in terms of infrastructure (fencing, watering, etc.) and allowing for income generation through ecotourism, safari, hunting, and meat production.
To compare the two forms of management, ground beetles were chosen as they have been shown “to be good ecological indicators for biodiversity in many ecosystems” and “are sensitive to changes in structural diversity and small scale habitat changes, easy to sample and extremely species rich in arid systems.”
On the 10,500-hectare wildlife reserve, there were approximately 4500 ungulates of 14 species, for a stocking rate of 51.46 kg/ha, “a comparable measure to the production of livestock on the neighbouring holistically managed farm” which has 4741 animals across 9,000 hectares. Beetle populations were studied during the summer growing season, the beginning of winter, and the non-growing season. Vegetation was also surveyed, including bare ground, total vegetation and litter, number of grass species, and percentage cover for each species.
Results showed 16 grass species, all of which were found on the Holistic Management site and 6 of which were found on the wildlife conservancy. The 3 grass species with a Climax successional status were only found on the Holistic Management site. For beetle populations, 220 specimens of 33 species (18 unique) were found on the holistically managed site while 309 species of only 20 species (6 unique) were found on the wildlife conservancy, showing that while the conservancy had a greater total number of beetles, it also had less diversity.
Overall, the holistically managed livestock operation demonstrated greater species richness and biodiversity for both vegetation and beetle populations. While species of beetle differed across the two sites, indicating that Holistic Management doesn’t necessarily “mimick wildlife grazing” as some claim, it provides a superior ecological impact nonetheless.
Citation: Reinhard, J.E., Geissler, K. & Blaum, N. Grass and ground dwelling beetle community responses to holistic and wildlife grazing management using a cross-fence comparison in Western Kalahari rangeland, Namibia. J Insect Conserv (2022). https://doi.org/10.1007/s10841-022-00410-6