Implication of abandoned cattle enclosures on ungulate herbivory, plant species and macro-invertebrate diversity in Save Valley Conservancy, Zimbabwe
- Author
- Chikorowondo, G.
- Title
- Implication of abandoned cattle enclosures on ungulate herbivory, plant species and macro-invertebrate diversity in Save Valley Conservancy, Zimbabwe
- Abstract
- African savannas are experiencing a shift in land-use, away from livestock farming towards wildlife conservation. The abandoned livestock areas may have implications on biodiversity and ecosystem functioning, as they create valuable nutrient-rich patches across the dystrophic semi-arid savanna. This study aimed at assessing the influence of abandoned kraals on the interactions between herbivory and plant assemblages, taxonomic and functional diversity of macro-invertebrates on a 22 year old abandoned cattle ranching site in Save Valley Conservancy. We tested whether the abandoned kraals were still soil nutrient-rich. We further studied vegetation structure and composition, forage properties, herbivory, taxonomic and functional composition of macro-invertebrates. After 22 years, the abandoned kraals still show significantly higher concentrations of soil nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na) and organic carbon (C). Although, herbaceous (grass and forbs) productivity was higher on abandoned kraals, herbivory was more pronounced on grass forage species with increased foliar nutrients than forb forage species. Only herbaceous biomass for grasses had a significant influence on the interaction between plants and herbivory while no clear relationships were observed between forage quality and herbivory and plant species diversity. Macro-invertebrate richness was generally high on abandoned kraals and only the species diversity of the belowground taxa responded significantly to the influence of abandoned kraals. Soil nutrients and herbaceous productivity had strong positive correlations with the abundant belowground and aboveground taxa respectively. At functional level, abandoned kraals had the higher functional richness, functional divergence and functional dispersion when both aboveground and belowground species are combined. However, much of the functional diversity indices were significantly high for the belowground habitat. This is a novel finding suggesting the vulnerability of the belowground habitat to resource patchiness. Functional response groups did not vary between kraals and controls indicating that the habitat is in the process of recovering to stability. The study concludes that abandoned kraals are nutrient-hotspots with potential of influencing soil-plant-herbivore interactions, taxonomic and functional assemblages of macro-invertebrates.
- Date
- JULY 2018
- Publisher
- BUSE
- Keywords
- abandoned cattle enclosures
- plant species
- herbivory
- Supervisor
- Dr. Justice Muvengwi
- Dr. Monicah Mbiba
- Professor Edson Gandiwa
