Abundance and Structure of African Baobab (Adansonia digitata) across Different Soil Types in Gonarezhou National Park, Zimbabwe

Abstract

This study investigated the abundance and structure of African baobab (Adansonia digitata) across soil group strata in Gonarezhou National Park, Zimbabwe. The study was based on a stratified random sampling design composed of the following soil group substrates: (i) granophyres, (ii) malvernia, and (iii) rhyolite. Belt transects of 0.3×0.1 km were randomly laid across soil group. Baobab abundance and population structure were determined from the density and size class distribution, respectively. There were significant differences in plant height and plant density across Gonarezhou soil groups. Study sites on granophyres derived soil group indicated viable abundance and recruitment of baobab population. Whereas the study highlighted a concern over the unbalanced size structure distribution of baobab population on malvernia derived soil group, our results indicated that baobabs are in danger of extirpation on malvernia derived soil group. Baobab community in Gonarezhou tends to occur more densely along environmental gradient of soil group type as influenced by the underlying geological soil substrate of granophyres. Malvernia derived soil group is likely less ideal for baobab recruitment.

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

“…According to earlier studies [27] and [28], this is a key parameter of woody vegetation structure of importance to black rhino forage since mostly consumed shrubs are of a height below 2 m. The importance of woody vegetation to black rhinos largely depends on the availability of preferred quality browse within the reach (plant height ≤ 2 m) of the rhinos [26]. The synergy between the commonly reported fires and intense herbivory in GNP [12] [29] [30] will likely continue to contribute to the general modification of habitats, for example, reduced woody plant height and increased number of stems per plant, thereby, replacing woodlands with shrublands patches. This woody vegetation structural change likely to proliferate and persist across northern GNP, given the recorded no significant difference in shrub density and shrub canopy volume across the study strata could continue to set this section of the park as an ideal area for black rhino re-introduction.…”

A Taxonomic Revision of the Genus Selaginella (Selaginellaceae: Lycopodiopsida) From Pakistan

“…In areas where elephant density are high, woodlands can be converted to a grasslands (Owen-Smith et al, 2006). This land cover modification mostly takes place through elephant herbivory, including tree toppling, pollarding whole trees, by breaking and removing branches from their canopies and by preventing or reducing woody plant recruitment and regeneration (Balfour et al, 2007 ;Mashapa et al, 2013). However, the spatial variation of elephant impacts on woody vegetation still needs more understanding, given that the relationship between elephant density and the ecological impact of elephants is complex and variable (Balfour et al, 2007).…”

Pinpointing baobab (Adansonia digitata [Linn. 1759]) population hotspots in the semi‐arid areas of Tanzania

“…Insight into how individual species' distribution and abundance are influenced by environmental factors is critical (Condit, Engelbrecht, Pino, Perez, & Turner, ). At a large scale, rainfall has been shown to influence species distribution (Amissah, Mohren, Bongers, Hawthorne, & Poorter, ; Engelbrecht et al, ; Toledo et al, ), whereas at smaller scales, soil fertility, topography and irradiance can affect species distribution (John et al, ; Mashapa, Zisadza‐Gandiwa, Gandiwa, & Kativu, ). Most tropical forests show seasonal variation in rainfall, and species drought performance and physiological drought tolerance have therefore been found to determine the distribution of tropical species (Baltzer, Davies, Bunyavejchewin, & Noor, ; Engelbrecht et al, ).…”

“…High annual rainfall may, therefore, not necessarily be the primary factor in determining high baobabs densities. Wetter areas have relatively high baobab densities in comparison with dry areas (Edkins et al, 2008;Mashapa et al, 2013;Mpofu, Gandiwa, Zisadza-Gandiwa, & Zinhiva, 2012). We found a significant main effect of rainfall on baobab density across the semi-arid region.…”