Browsing by Author "Coetzer, Willem G."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    A phylogeographic assessment of South African greater cane rats (Thryonomys swinderianus): Preliminary insights
    (Pensoft Publishers, 2023-03-28) Coetzer, Willem G.
    The greater cane rat (Thryonomys swinderianus) is an African rodent with a wide Sub-Saharan distribution range. This species is viewed as an important protein source in many African countries. These rodents are also regularly viewed as a pest species who frequently raid croplands in agricultural settings. No phylogenetic work has to date been published on T. swinderianus from southern Africa. This paper therefore reports the first phylogenetic assessment on the species across the South African distribution range. Thirty samples were sourced from local museum collections, with one direct submission by a member of the public who found a rodent carcass identified as T. swinderianus west of its known distribution range in the Eastern Cape Province of South Africa. Two mitochondrial loci previously used in West African studies of this species were used in the current study to asses T. swinderianus population genetic diversity and phylogenetic structure across the South African distribution. A comparison to sequence data from West Africa was also performed. A divergence time estimation was conducted to further investigate the evolutionary history of the South African sub-population. Similar genetic diversity estimates were observed for the South African sub-population when compared to the West African datasets. Specimens from the eastern parts of South Africa showed higher genetic diversity estimates, possibly indicative of an initial colonisation site from eastern Africa. Two distinct phylogenetic clades were identified by Bayesian inference, forming distinct West African and South African groups. The divergence estimates showed similar ages for the T. swinderianus most recent common ancestor (MRCA) as previously reported. The MRCA estimates for the South African group identified a possible middle to late Pleistocene migratory event from eastern African into southern Africa. Further fine scale sampling across the African distribution range is however needed to provide more accurate assessments for future conservation management planning for the different sub-populations, as needed.
  • Thumbnail Image
    Item
    Natural recovery of old crop fields in a South African grassland biome
    (Wiley, 2023-09-18) Coetzer, Willem G.; Coetzer, Kayleigh
    Changing land-use practices have led to an increased rate of cropland abandonment in South Africa. Globally, climate change has increased the need for additional studies on the impact of land abandonment on soil health in arid and semi-arid environments. We, therefore, aimed to measure the changes in soil health with time following abandonment. The study site is located in the Winterberg Mountains of the Eastern Cape Province, South Africa. Standard soil characteristics were assessed for three recovering old crop fields. Samples from the surrounding natural habitat were also included for comparison. Significant positive changes in soil water-holding capacity and carbon and nitrogen characteristics were observed with increased age since abandonment, pointing to soil quality recovery. It will, however, still take a significant amount of time for total recovery to be achieved. Continuous monitoring of old crop fields in agricultural and formally protected areas is needed to fully understand the long-term effects of cropping on soil quality in this region.