Structure and Composition of Androstachys johnsonii Woodland across Various Strata in Gonarezhou National Park, Southeast Zimbabwe

Abstract

A study on the structure and composition of Androstachys johnsonii Prain (Euphorbiaceae) woodland across three strata was conducted in Gonarezhou National Park (GNP), southeast Zimbabwe. Specifically, the objectives of the study were: (i) to determine the spatial structure and composition of A. johnsonii woodland in GNP and (ii) to determine factors that influence the structure and composition of A. johnsonii woodland in GNP. This study was based on a stratified random design with three major soil groups, and 30 plots were sampled in May 2010. The three soil strata were comprised of soils derived from (i) rhyolite, (ii) malvernia and (iii) granophyre bedrocks. A total of 1258 woody plants were assessed and 41 woody species were recorded. There were significant differences in mean tree heights, tree densities, basal area and species diversity in A. johnsonii woodland across the three soil strata. In contrast, there were no significant differences in the mean number of dead plants per ha in the three study strata in the GNP. Our study findings suggest that A. johnsonii woodland in GNP is being degraded. GNP management should develop a monitoring program through establishing monitoring plots in A. johnsonii woodland, and further studies need to be carried out, particularly on recruitment of A. johnsonii in the GNP.

Assessment of Browse Availability and Suitability for Black Rhino’s Re-Introduction in Northern Gonarezhou National Park, Southeastern Zimbabwe

“…Spirostachys, Dichrostachys and Acacia genera which are known palatable quality browse suitable for black rhino's feed [20] [21] were recorded with high frequency occurrence within the northern side of the Runde River study stratum, suggesting it to be a more suitable sanctuary space for the proposed re-introduction of black rhinos in northern GNP. Earlier studies in GNP confirmed abundance of Spirostachys woodlands [31] and Acacia woodlands [24] within northern GNP. The study results highlighted that north of Runde River Table 2).…”

Status of African baobab (<i>Adansonia digitata</i>) across Gonarezhou National Park, Zimbabwe

“…Gonarezhou has a relatively low relief, with the park altitude varying between 165 m above sea level to 578 m above sea level. The study area was stratified following Gandiwa et al (2011). Gonarezhou was divided into three strata based on natural and physical features.…”

“…Baobab damage by elephants was assessed on a 4-point scale, from 0 = no damage, 1 = slight damage with few scars: 2 = moderate damage with numerous scars; 3 = severe damage with the tree scarred deeply and 4 = tree dead or felled (Swanepoel 1993). Moreover, elephant dung counts following Gandiwa et al (2011), grass height, habitat site relief elevation (using a Global Positioning System (GPS) unit) and habitat site rockiness (through visual inspection) in belt transects were recorded. Data were first summarized by descriptive statistics for each belt transect.…”

Geology drives the spatial patterning and structure of termite mounds in an African savanna

“…Mean annual rainfall at the study site averages 466 mm, and mean monthly maximum temperatures range between 26°C in July and 30°C in January, whereas mean monthly minimum temperatures range between 9°C in June and 24°C in January (Gandiwa et al. ). Granite is located in the east and has higher tree species diversity than basalt in the west.…”