Impacts of wood poaching on vegetation structure

Our study focused on the effects of wood poaching on the vegetation structure and composition in Mukuvisi Woodland, Zimbabwe. Mukuvisi Woodland, located within the precincts of Harare urban area, Zimbabwe, suf-fers from high illegal wood utilization pressure stemming from the need to fulfill alternative energy demands created by persistent electricity shortages and an unstable economic environment, particularly between 2000 and 2008. This results in a continuous flux of vegetation and a disturbed animal habitat driven mainly by anthropo-genic activities. Due to the heterogeneity in vegetation utilisation trends, we used the stratified systematic ran-dom sampling technique, where the site was divided into two strata, central and boundary. Twelve 30 × 20 m permanent plots were established in which species name, species diversity, height, basal area, plant status, fire evidence, number of stems and saplings were recorded and assessed in April and May 2012. A total of 968 woody plants were assessed representing 47 woody plant species. All woody vegetation variables recorded and assessed showed no significant difference (P > 0.05) between the two strata, i.e., central and boundary, in Mukuvisi Woodland, except sapling density (P = 0.022). Principal Component Analysis indicated evidence of fire impacts on vegetation structure. The study concludes that illegal wood harvesting in Mukuvisi Woodland has not yet reached alarming proportions and can be contained. The study recommends collaborative arrangements with key stakeholders, promotion of the use of alternative energy sources and increased environmental education and awareness campaigns.

2007

I, John Mudekwe, the undersigned, hereby declare that the work contained in this dissertation is my own original work and that I have not previously in its entirety or in part submitted it at any university for a degree.

2016

Copyright © 2014 Never Muboko et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In accor-dance of the Creative Commons Attribution License all Copyrights © 2014 are reserved for SCIRP and the owner of the intellectual property Never Muboko et al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian. Our study focused on the effects of wood poaching on the vegetation structure and composition in Mukuvisi

Open Journal of Forestry

Illegal wood harvesting, a factor that threatens conservation efforts, was assessed in Chimanimani National Park (CNP), eastern Zimbabwe, in April 2016. The study identified preferred indigenous woody species, determined the uses and quantities of indigenous wood extracted, and established local people's knowledge and perceptions on forest resource conservation, institutional framework and management by-laws. Mixed data collection methods, which included questionnaires and semi-structured interviews were used. For questionnaires, a three-stage sampling design was adopted; that is, purposive sampling, where three Wards (i.e. Chikukwa Ward 11, Chikwakwa Ward 17 and Ngorima Ward 5b) were selected as study areas from a total of seventeen Wards in Chimanimani District. The three selected Wards had a combined total of 15 villages. Stage 2 involved random sampling, where three villages, one from each selected Ward, i.e. Batanai (75 households), Chikukwa (110 households) and Tamuka (46 households), with a total of 231 households, were chosen. Stage 3 was the random selection of households, where 46 questionnaires were administered and collected in the 3 selected villages, representing 20% of the targeted population. The study results highlighted that the preferred woody species included those of Acacia, Bauhinia, Brachystegia, Combretum, Pericopsis and Terminalia genera. The illegally harvested indigenous woody plants were principally for household uses. Quantities collected ranged from 0.2 to 0.4 tons for firewood monthly and 3 to 6 tons mostly for tobacco curing. Most respondents reported that by-laws were not effective in combating illegal wood harvesting. It was concluded that CNP woodlands are under pressure due to illegal wood harvesting.

We assessed woody vegetation composition and structure in Mapembe Nature Reserve, eastern Zimbabwe. Woody vegetation was sampled during the period May-June in 2012. Using a stratified random sampling design, we delineated the study area into three strata; plains, mountain and wetland areas. We recorded a total of 1 443 woody plants representing 17 woody species assessed from 30 sample plots. Our results from Kruskal Wallis-H test showed significance differences in plant height, canopy volume, and tree density across the study strata (P < 0.05). In contrast, no significant differences were observed in basal area, shrub canopy volume, shrub density and woody species diversity. Our study results highlighted woody vegetation degradation on wetlands and mountains of Mapembe Nature Reserve, which was attributed to anthropogenic factors. The study recommends in-depth woodland inventory, collaborative arrangements with the local surrounding human communities and improved law enforcement strategies. ©JASEM

Ngonidzashe Jangano , 2022

Tropical deforestation through clear-cut and subtle logging activities poses a direct threat to biodiversity. The application of remote sensing and Geographical Information Systems (GIS) in spatial ecology has enabled the monitoring of tree species diversity and quantification of deforestation in space over a period of time. The ability to use remotely sensed diversity is important for the management of ecosystems at large spatial extents. However, to achieve this, there is still need to develop robust methods and approaches that enable large-scale mapping of species diversity and detection of deforestation in savanna woodlands. Thus, the main objective in this thesis was to use a GIS and remote sensing-based method for predicting tree species diversity, as well as to measure spatial variations in tree species data across the savanna ecosystems of Zimbabwe. Specifically, we tested whether and in what way tree species diversity is related to the spatial variations in tree species density. Our results showed that linear and non-linear regression relating to tree species diversity can be successfully used to map the spatial variations in tree species diversity in savanna woodlands. High tree species diversity is associated with high tree species density and is associated with less deforestation. High tree species diversity is also associated with high density and vice versa and at intermediate levels is associated with high tree species diversity and NDVI. However, disturbance through deforestation may be not be a mechanism driving the patterns observed since the results indicate no significant differences (r2> 0.5615) in tree species diversity among the sampled plots areas in dense Landover and (r2> 0.764) in tree species diversity among sampled plots in sparse landcover type. We also found logistic regression can be successfully used to predict deforestation in savanna woodlands. Overall, we conclude that remotely sensed data could provide an effective predictive tool for monitoring species diversity and detection of logging.

International journal of innovation and scientific research, 2014

This study assessed Woodstock, species richness, tree diversity and Importance Value Index (IVI) of Chenene Forest Reserve (CFR). Forest inventory carried out in 120 systematically selected sample plots. The forest was post stratified into disturbed and undisturbed strata. The information recorded includes: diameter at breast height, species name, Geographical Positioning System (GPS) readings, and frequency of the species. Indicators of human activities such as charcoal kilns, pitsawing, burnt area and grazing signs. Analysis of the inventory data was done using Microsoft Excel. The inventory carried out in 2011 revealed that average number of stems per hectare (N), basal areas per hectare G (m2ha-1), and volume per hectare V (m3ha-1) as 352 35.20 (SE), 6.84 0.68 (SE) and 44.68 4.47 (SE) respectively. The parameters between disturbed and undisturbed strata in this study revealed low parameters in disturbed stratum as compared to undisturbed strata were 567± 87.37 stems ha-1, Basal ...

Dry forests are seriously under threats, mostly linked to human disturbance. In Togo where continuous deforestation is ongoing, it important to assess woody species diversity that maintain forest structure and functions. In that concern, this study was carried out in Abdoulaye Wildlife Reserve (AWR) with a specific objective to assess woody species diversity. A total of 258 plant species belonging to 119 genera and 63 families were found in AWR dry forests. Of this total, 67 woody species with 903 individuals and 52 genera were recorded. The highest relative frequencies were recorded by Anogeissus leiocarpa (83.37%), Pouteria alnifolia var. alnifolia (73.37%), Cola gigantea (50%), Diospyros mespiliformis (50%) and Dialium guineense (40%). The lianas species are dominated by Rourea coccinea, Dioscorea dumetorum, Cissus populnea, Dioscorea burkilliana whereas the dominated herbaceous of the undergrowth layer were Anchomanes difformis, Chromolaena odorata, Olyra latifolia and Oplismenus hirtellus. Three stand groups were revealed and the study highlighted trees bushfire and breakage as main threats on species diversity. These human pressures were highest in G III. Globally, Pielou's index varied from 0.78 to 0.85. All these groups were dominated by A. leiocarpa. The study suggests conservation strategies to protect woody species against anthropogenic pressures (for example, protection from or reducing the frequency and/or intensity of disturbance, especially woodcutting and bushfires).

2014

The present study was carried out as a survey to find out the harvesting and consumption patterns of firewood in the wake of electric power cuts that are currently being experienced in the entire Zimbabwean nation. The survey was carried out in Bulawayo and it covered randomly selected high-density and medium- density residential areas. Interviewer-completed and semi-structured questionnaires were administered to residents in the selected residential areas. The average mass of a firewood bundle was measured using a balance. Firewood was found to be the most popular alternative energy source in the absence of electricity (76%), followed by paraffin (10%), gas (7%), jelly fuel (6%) and finally coal (1%). Residents were found to prefer indigenous energy tree species to exotic ones with Colophospermum mopane (39%), Acacias (24%) and Ziziphus mucronata (16%) being the most popular ones while Eucalyptus, Jacaranda and Pine are used in very rare cases. There was significant difference (p<0.05) in mean mass of firewood consumed between high and medium-density suburbs, with the former consuming more (1.79 tonnes per household) than the latter (1.13 tonnes per household). A high positive correlation was also noted between the duration of power cuts and the use of firewood. Keywords: Firewood, Electric power cuts, High-density area, Medium-density area

Koedoe, 2009

We investigated the long-term effects of fi re frequency on Colophospermum mopane and Combretum apiculatum woodland structure and composition in northern Gonarezhou National Park (GNP), Zimbabwe. Fire frequency was categorised as high (every 1-2 years), medium (every 3-4 years) and low (every 5-6 years). The following variables were measured or recorded: plant height, species name, canopy depth and diameter, basal circumference, number of stems per plant, plant status (dead or alive) and number of woody plants in a plot. There was a positive correlation (r = 0.55, P = 0.0007) between annual area burnt (total from January to December) and annual rainfall (average over two rain stations per rain year, July to June) between 1972 and 2005. A total of 64 woody species were recorded from C. mopane and C. apiculatum woodlands. Mean plant height increased from 4.5 to 8.2 meters in C. mopane woodland and from 4.5 to 5.1 meters in C. apiculatum woodland in areas subjected to high and low fi re frequencies. In C. mopane woodland, low fi re frequency was characterised by a signifi cantly low density of woody plants (P < 0.001), however, with a signifi cantly high mean basal area (P < 0.001). Fire frequency had no signifi cant effect on species diversity (P > 0.05). Our results suggest that C. mopane and C. apiculatum woodlands are in a state of structural transformation. Fire frequency effects, however, appear to be woodland specifi c. Fire management strategies in GNP should take into consideration annual rainfall and the different vegetation types. Conservation implication: This study provides valuable information on fi re frequency effects on woody vegetation in northern GNP, which can be used in fi re management programmes for the park. The positive relationship between annual rainfall and annual area burnt emphasises the need for wildlife managers to consider annual rainfall in fi re management.