Structure and composition of Androstachys johnsonii woodland across various strata in Gonarezhou National Park, southeast Zimbabwe

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

Law enforcement staff perceptions of illegal hunting and wildlife conservation in the Gonarezhou National Park, southeast Zimbabwe

Globally, pressure from the illegal harvesting of wildlife is a recurrent issue for protected area management. In order to ensure the effective conservation of wildlife resources, law enforcement has been identified as one of the most important components of protected area management. Our study aimed at addressing the following two research questions: (1) what are the perceptions of law enforcement staff in Gonarezhou National Park (GNP), Zimbabwe, about illegal hunting practices, illegal hunter’s characteristics, wild animals commonly targeted and trends of poaching in the park; and, (2) what are the suggestions for reducing illegal hunting and enhancing wildlife conservation in GNP ecosystem? Data were collected using a semistructured questionnaire administered through interviews from 42 law enforcement staff representing 47 % of the total law enforcement staff in GNP from February to May 2011. Our results showed that 76 % (n = 32) of the patrol rangers perceived that most illegal hunters were between 21 and 30 years. Nearly all respondents (95 %; n = 40) reported that most poachers were residents of villages situated within 20 km from the boundary of GNP. Medium to large wild herbivores were reportedly the most illegally animal hunted species whilst large carnivores were the least illegally hunted animals. Most of the respondents (79 %, n = 33) perceived that poaching activities had declined in GNP ecosystem between 2005 and 2010 due to an increase in arrests. Increasing conservation awareness and education in adjacent communal areas would help to further reduce illegal hunting and promote wildlife conservation

An assessment of illegal fishing in Gonarezhou National Park, Zimbabwe

Illegal fishing is a worldwide problem. In this study we present the first assessment of illegal fishing in Gonarezhou National Park (GNP), Zimbabwe. Information on illegal fishing was gathered from a total of 39 illegal fishers who were arrested within GNP between February and October 2011. Data was collected using semi-structured questionnaires that were administered through interviews. Our results showed that most of the illegal fishing was undertaken by women (n = 32, 82%). Most of the illegal fishers were middle-aged, less educated, and came from poor families characterised by a high number of dependents. Illegal fishing was largely carried out using fishing nets with harvested fish being sold and also being consumed at household level. Despite the perceived increase in law enforcement in GNP, respondents reported that illegal fishing had also increased due to rising poverty in communities adjacent to the park. Increasing conservation awareness, law enforcement and establishing irrigation projects would help in further reducing illegal fishing

Status of woody vegetation along riparian areas in Gonarezhou National Park, Zimbabwe

We assessed the composition and structure of woody vegetation along Save, Runde and Mwenezi rivers in Gonarezhou National Park, Zimbabwe. Data were collected from 62 sample plots between April and May 2011 using a stratified random sampling design. Our results showed significant differences in plant height, shrub density and numbers of stems per plant across the three major perennial rivers. However, there were no significant differences in basal area, tree density, dead plant density, browsed plant density, fire damaged plant density and species diversity. Our findings suggest that disturbances, e.g., herbivory, are affecting the woody vegetation structure in all major rivers in Gonarezhou. We therefore, recommend for the continuous monitoring of riparian vegetation in Gonarezhou and other similar protected areas

Abundance, distribution and population trends of Nile crocodile (Crocodylus niloticus) in Gonarezhou National Park, Zimbabwe

The Nile crocodile (Crocodylus niloticus) is an iconic or keystone species in many aquatic ecosystems. In order to understand the abundance, distribution, and population trends of Nile crocodiles in Gonarezhou National Park (GNP), southeastern Zimbabwe, we carried out 4 annual aerial surveys, using a Super Cub aircraft, along 3 major rivers, namely, Save, Runde and Mwenezi, between 2008 and 2011. Our results show that Runde River was characterised by a significant increase in Nile crocodile abundance whereas both Save and Mwenezi rivers were characterised by non-significant increases in Nile crocodile abundance. Overall, we recorded a significant increase in total Nile crocodile population in the three major rivers of the GNP. The non-significant increase in Nile crocodiles in the Mwenezi and Save rivers was likely due to habitat loss, through siltation of large pools, and conflicts with humans, among other factors. We suggest that GNP management should consider halting crocodile egg collection in rivers with low crocodile populations and continuously monitor the crocodile population in the par

Variation in woody vegetation structure and composition in a semi-arid savanna of southern Zimbabwe

The objectives of this study were: i) to establish the status of woody vegetation structure and composition, and ii) to determine the main factors influencing woody vegetation structure and composition across Gonarezhou National Park, Zimbabwe. We divided the park into three large strata based on natural and artificial features. A total of 137 sample plots were randomly placed to gather data on woody vegetation in the three study strata across Gonarezhou National Park from May to June 2011. Trees constituted 66% and shrubs 34% of the woody plants sampled. A total of 132 woody plant species were recorded. Significant differences were found in basal area, shrub density, browsed plants density and woody species diversity across Gonarezhou National Park. In contrast, no significant differences were recorded in tree height, densities of trees, stems, dead plants and fire damaged plants. Our results suggest that there are some variations in woody vegetation structure and composition across Gonarezhou National Park. These variations could be attributed to both natural and anthropogenic disturbance factors including elephant (Loxodonta africana Blumenbach) browsing, fires, droughts and previous tsetse fly (Glossina spp.) (Diptera: Glossinidae) eradication activities in the park

Vegetation structure and composition across different land use in a semi-arid savanna of southern Zimbabwe

We compared the structure and composition of vegetation communities across different land uses in the northern Gonarezhou National Park and adjacent areas, southeast Zimbabwe. Vegetation data were collected from 60 sample plots using a stratified random sampling technique from April to May 2012. Stratification was by land use, and sample plots in all three strata occurred on predominantly siallitic soils. Our results show that the communal area had higher woody plant species diversity (H' = 2.66) than the protected area (H' = 1.78). However, the protected area had higher grass species richness per plot than the communal area and resettlement area. Overall, the protected area had more structural and compositional diversity than the other land use areas. These findings suggest that the areas adjacent to protected areas contribute to plant diversity in the greater ecosystem; hence conservation efforts should extend beyond the boundaries of protected areas. We recommend that protected area management should engage community-based institutions in neighbouring areas for effective monitoring of woody vegetation structure and composition

Few figs for frugivores: Riparian fig trees in Zimbabwe may not be a dry season keystone resource

Most plants flower and fruit at times of year when probabilities of pollination and seedling establishment are high. Fig trees (Ficus spp.) are often considered as keystone resources for vertebrate frugivores, in part because of year‐round fig production. This unusual fruiting phenology results in the maintenance of fig wasp populations, but in seasonal environments this means fruiting occurs during periods when the chances of seedling establishment are low. Under these circumstances, selection is expected to favour any individuals that reduce or eliminate fruiting at these times. Here, we describe a large‐scale survey of the extent of dry season fruiting by three riparian Ficus species in Gonarezhou National Park, Zimbabwe. Few trees of two monoecious species, F. sycomorus and F. abutilifolia, had figs, and most crops of F. sycomorus were far smaller than the trees were capable of producing. Large stands of the dioecious F. capreifolia were present, but fig densities were low and no mature female (seed containing) figs were recorded. Even though fig trees may have been the only species bearing fruit, the consequences of the low investment in reproduction by the three Ficus species were clear—there were too few figs for a landscape‐scale keystone role

Wildlife management in Gonarezhou National Park, southeast Zimbabwe: Climate change and implications for management

Climate change is not a new phenomenon; the only constant about climate throughout Earth’s history is that it has changed (Marchant, 2010). An earlier study in Africa indicated that some Southern African ecosystems are highly sensitive to climate change (e.g., Magadza, 1994). Climate change in Africa is expected to lead to higher occurrence of severe droughts in semiarid and arid ecosystems (Foley et al., 2008). For instance, a severe drought associated with the El Niño-Southern Oscillation phenomenon was recorded in 1991–92 in Southern Africa. In Zimbabwe, the most affected areas in terms of wildlife and ecological systems in the 1991–92 drought were recorded in the southeastern parts of the country (Magadza, 1994)

Structure and composition of woody vegetation around permanent-artificial and ephemeral-natural water points in northern Gonarezhou National Park, Zimbabwe

The main objective of this study was to compare woody vegetation structure and composition along a distance gradient from permanent-artificial and ephemeral-natural water points in northern Gonarezhou National Park (GNP), Zimbabwe. Woody plants were sampled in May 2010 using a stratified systematic design with plots systematically placed at 100, 500, 1000 and 2000 m from four selected water points. A total of 912 woody plants were assessed in 32 sampling plots and 63 woody plant species were recorded. There were no significant differences in mean height, number of stems per plant, density and diversity with distance from water points. Significant differences in basal areas were only recorded at 2000 m. Only one ephemeral-natural water pan showed a decrease in plant density with increase in distance from the water pan. Our results suggest that there has been some slight degradation of woody vegetation around water points in northern GNP