28 research outputs found
The impacts of herbivores and humans on the utilisation of woody resources in conserved versus non-conserved land in Maputaland, northern KwaZulu-Natal, South Africa
This study presents an exploration of the structure, dynamics and utilisation of woody plants in vegetation units of northern Maputaland. Animal (in Tembe Elephant Park) and human (in the rural community of Manqakulane) utilisation of woody plants were compared against a control area (Tshanini Community Conservation Area) where animals were extirpated and people were precluded through tribal rules. The tree assemblages of the unique Sand Forest were explored, and compared with previous studies. A new classification was proposed and a new subcommunity was established. Contrary to previous studies, a gradient from Short to Intermediate to Tall Sand Forest was defined, and it was suggested that structurally different Sand Forest subcommunities represent a mosaic of different evolutionary states, rather than stationary states as perceived currently. Animal utilisation appeared to have transformed Sand Forest in conserved land to such an extent that it no longer resembled Sand Forest outside conserved areas. The structure of Sand Forest and woodlands of the region was evaluated at the vegetation unit level (21 vegetation units), through a size and height class distribution analysis of woody plants. Humans and animals had clearly modified the woodlands and appeared to force succession from closed woodland to open woodland. The Sand Forest appeared to benefit from low intensity animal utilisation, with increased diversity, and possibly enhanced dynamics. However, signs that current animal utilisation have negative effects were perceived. The size class distribution of Sand Forest and woodland woody species was presented and an analysis of species grain was performed. The grain concept was successfully applied to woodland species for the first time. It appeared that nearly all vegetation units were fine-grained, and therefore governed by small-scale dynamics. Frequent small disturbances are necessary to maintain diversity. There was cause for concern that current animal and human utilisation threaten such fine-scale dynamics. The utilisation level by the browsing mammals guild in Tembe Elephant Park and by small browsers and people in Manqakulane Rural Community were evaluated over two periods. Small to medium browsers utilised more woody species and height classes than any other agent, but with short-term effects. However, utilisation marks linked to elephants and people were accumulating significantly, and the long-term effects of these agents were threatening the dynamics of Maputaland vegetation. The case of woody species utilisation by elephants was evaluated further and compared with a previous study. Overall utilisation by elephants reached 100% of individuals for several woody species, while other speciesâ regeneration potential was severely threatened. Woody species preferred in 1994 were nearly extirpated. Utilisation of woody species by elephants throughout Tembe Elephant Park appeared correlated with distance to permanent water points during a dry spell. In conclusion, it appeared clear that policies in favour of high animal numbers in formally conserved areas were not suited for northern Maputaland and this result should be considered when the expansion of the South African protected areas of Maputaland into Mozambique becomes effective. Community-based conservation appeared promising, but novel ways of generating income should be investigated.Thesis (PhD (Wildlife Management))--University of Pretoria, 2008.Animal and Wildlife Sciencesunrestricte
A step closer to local carbon calculations : growth timescales and linear relationships for sand forest and woodland tree species in Maputaland, South Africa
In Africa, information on time required for plants to develop from seed to mean size and maximum
size is scarce. There is also a lack of information regarding accurate relationships between
stem diameter, height and canopy dimensions. This type of information is however becoming a
real necessity to allow the accurate measurement of carbon stocks and carbon stocks change to
qualify for the UNFCCCâs REDD+ mechanism. We evaluated these parameters for 22 Sand Forest
and woodland tree species of South Africaâs Maputaland. Results indicated that it takes approximately
66 and 35 years for current dynamics of Sand Forests and woodlands to occur respectively.
Based on diameter and growth rates, larger trees of the forests can be older than 600 years, while
large woodland trees can reach ages of 900 years. Our evaluation of linear relationships between
stem diameter, height and canopy dimensions showed extremely robust results allowing the use
of stem diameter to calculate height and canopy dimensions. The results are of interest for carbon
related investigations and reconstructing stands dynamics.The University of Pretoria and the South African National Research Foundation under Grant Number 2053522.http://www.scirp.org/journal/ojfam201
Herbivore and human impacts on woody species dynamics in Maputaland, South Africa
Maputalandâs woodlands are under utilization pressure inside and outside conserved areas due to mounting densities of mammals in the former and increasing human utilization of vegetation in the latter. Conservation of this biodiversity hotspot requires a better understanding of vegetation dynamics. To this purpose, woodland vegetation structure was evaluated at three sites through size class distribution analysis and grain determination, a forestry concept here applied to woodlands. The three sites represented animal disturbance/utilization, human disturbance/utilization and no disturbance/utilization regimes for comparable periods. Common species occurrence patterns differed between sites. The woodlands of all three sites were mostly fine-grained forest-like vegetation units and followed fine-grained forest dynamics closely. The grain model performed successfully for the regionâs woodlands and proved a good tool to improve vegetation dynamics understanding. In general, people and herbivores led to local extirpation of species and threatened both ecological structure and function of Maputalandâs woodlands. However, the fine grain status was considered positive, as it facilitated future management options by reducing time frames and scale of management actions to be applied.The South African National Research Foundation under Grant Number 2053522 and the University of Pretoria.http://forestry.oxfordjournals.org/hb201
Woody vegetation utilisation in Tembe Elephant Park, Kwazulu-Natal, South Africa
A survey of woody plant species utilisation by large (excluding elephants), medium and small browsers,man and ânatural damageâ, was conducted in nine vegetation units of Tembe Elephant Park, KwaZulu-Natal, South Africa. Woody species use and canopy removal were evaluated within two age ranges, (a) recent, †12 months prior to
study and (b) old, > 12 months prior to the study. The results show that recent canopy removal by medium and small browsers was intensive and generally represented one
third of height classes available to the agents which were consistently used within all vegetation types. The overall utilisation pattern indicated that medium and small
browsers may be removing the regeneration class of the woody plants layer. Natural damage was found to be considerable and it was hypothesized that it may be linked and possibly amplified by prior elephant utilisation.
In conclusion, it is possible to suggest that the regular use of the sapling level by small and medium browsers
could promote woodland to grassland retrogression, as was found in east Africa under high densities of animals.http://www.ccsenet.org/journal/index.php/ijbhb201
Is the present Brackenridgea Nature Reserve large enough to ensure the survival of Brackenridgea zanguebarica Oliv.?
The Brackenridgea Nature Reserve is a 110 ha protected area established by the provincial
Limpopo Department of Economic Development, Environment and Tourism as a way
of protecting the population of Brackenridgea zanguebarica, a species classified as critically
endangered in South Africa. In the whole of South Africa, the species is found in only one
small area around ThengweâMafukani in Venda. It is threatened with extirpation due to high
demand for its medicinal bark. This study investigated the adequacy of the reserve to conserve
the species using a method established in 2001 by Burgman et al. This method involves
12 steps to quantify the risk of the decline or possible extinction of the species and takes
current human activities, disturbances and the viability of the population into consideration
for setting a conservation target. From the results, it was clear that more area is needed for
the current population to survive beyond 50 years. Assuming the status quo, it will require
410 ha to maintain the population, whereas a 50% reduction in human-related activities, such
as cultivation, harvesting and livestock grazing, will lower the required potential habitat to
203 ha and a conservation option, which allows for bark harvesting, will require 179 ha.
CONSERVATION IMPLICATIONS: The results of this study will have conservation implication on
management of viable species population within a nature reserve. It will require managers to
take into consideration the reserve size in relation to potential habitats for the development of
species under their management.http://www.koedoe.co.zaam201
Floristic and phytogeographycal analysis of coastal and subcoastal vegetation in the Kouilou Department (Republic of Congo)
The zone of study is located north of Pointe noire town, in the Department of Kouilou, in Republic of Congo. In
order to better understand the floristic richness and chorology of the study site of interest, an analysis on a flora, of the
autoecological and phytogeographycal spectra of species was undertaken. This analysis is based on the floristic material from
different botanical surveys carried out in 2012, and deposited at the National Herbarium of the Congo (IEC). Over a study
area of 202â700 ha investigated through 243 phytosociological plots, a matrix of 580 specific and subspecific taxa, distributed
in 386 genus and 119 families, were inventoried. Seven species, of which one for the science, were new for the flora of
Republic of Congo. The families of Fabaceae, Poaceae, Rubiaceae, Euphorbiaceae, of Malavaceae and Annonaceae and are
the most diversified in species. The ecological spectrum highlights the strong preponderance of the phanerophytes,
sarcochores and mesophiles, thereby confirming the dominance of the forest biodiversity compared to grasslands. From a
phytogeographical perspective, the preponderance of the base element identified as well as three families and eleven genus
of endemic nature integrate the flora within the Guineo-Congolian centre of endemism.La zone dâĂ©tude est situĂ©e au nord de Pointe noire, dans le DĂ©partement du Kouilou, en RĂ©publique du Congo. Pour
mieux connaĂźtre la richesse floristique et la position chorologique du site dâintĂ©rĂȘt, une analyse sur la flore, des spectres
autoécologiques et phytogéographiques des espÚces a été entreprise. Cette analyse est basée sur le matériel floristique issu
de diffĂ©rentes prospections botaniques effectuĂ©es en 2012, et dĂ©posĂ© Ă lâHerbier National du Congo (IEC). Sur une superficie
de 202.700 hectares prospectée, au travers de 243 relevés phytosociologiques, une matrice floristique de 580 espÚces et
taxons infra spécifiques réparties en 386 genres et en 119 familles, a été retenue. Sept nouvelles espÚces, dont une nouvelle
pour la science, sont des ajouts Ă la flore du Congo. Les familles des Fabaceae, des Poaceae, des Rubiaceae, des
Euphorbiaceae, des Malavaceae et des Annonaceae et sont les plus diversifiées en espÚces. Les spectres écologiques mettent
en relief la forte représentativité des phanérophytes, des sarcochores et des mésophylles, confirmant de facto la
prĂ©pondĂ©rance de la biodiversitĂ© forestiĂšre par rapport aux formations herbacĂ©es. Sur le plan phytogĂ©ographique, la prĂ©pondĂ©rance de lâĂ©lĂ©ment base dĂ©celĂ© ainsi que la prĂ©sence de trois familles et de onze genres endĂ©miques, intĂšgrent bien
cette flore au Centre dâendĂ©misme guinĂ©o-congolais.http://www.ijias.issr-journals.org/am2017Centre for Wildlife Managemen
Floristic composition, diversity and structure of the forest communities in the Kouilou DĂ©partement, Republic of Congo
The objectives of the study were to classify, describe and map the forest
communities in the study area and to investigate possible gradients in plant diversity. The
study area comprised approximately 166 000 ha in the Kouilou DĂ©partement, Republic of
Congo, a section of land targeted for extensive future development. In total 156 forest sample
sites were surveyed using the Braun-Blanquet method of phytosociology. Diversity of each plant
community was expressed in terms of species richness; Shannon-Wiener index; exponent of
Shannon-Wiener index; evenness; Fisher's alpha; Simpsonâs index; and inverse Simpson index.
Eleven plant communities were described and mapped at a much finer scale than has been done
previously. The communities were arranged along two gradients: a degraded â relatively intact
gradient and a wet â dry gradient. The least degraded communities, and consequently those
with the highest conservation value, were the swamp forests and the okoumé forest. Overall,
the values reported for the diversity parameters in the current study were within the range
reported for other tropical forests in Central Africa. The study revealed a gradient between the
coast (west) and the Mayombe mountain range (east) in plant diversity linked to topography
and climate with plant diversity lowest at the coast. Furthermore, plant diversity was
negatively related to the distance to human infrastructure. The forest communities appear to be
fairly resilient to past anthropogenic disturbances, however, there is no historical analogue to
the more severe types of forest destruction associated with some of the future developments
anticipated, such as mechanized logging or mining.http://journals.cambridge.org/action/displayJournal?jid=TRO2017-06-30hb2017Centre for Wildlife ManagementPlant Scienc
Financing and current capacity for REDD+ readiness and monitoring, measurement, reporting and verification in the Congo basin
This paper provides the first critical analysis of the financing and current capacity for REDD+ readiness in the Congo Basin, with a particular focus on the REDD+ component of national forest monitoring and measurement, reporting and verification (M&MRV). We focus on three areas of analysis: (i) general financing for REDD+ readiness especially M&MRV; (ii) capacity and information for REDD+ implementation and M&MRV; (iii) prospects and challenges for REDD+ and M&MRV readiness in terms of financing and capacity. For the first area of analysis, a REDD+ and M&MRV readiness financing database was created based on the information from the REDD+ voluntary database and Internet searches. For the second area of analysis, a qualitative approach to data collection was adopted (semi-structured interviews with key stakeholders, surveys and observations). All 10 countries were visited between 2010 and 2012. We find that: (i) a significant amount of REDD+ financing flows into the Congo Basin (+US$550 million or almost half of the REDD+ financing for the African continent); (ii) across countries, there is an important disequilibrium in terms of REDD+ and M&MRV readiness financing, political engagement, comprehension and capacity, which also appears to be a key barrier to countries receiving equal resources; (iii) most financing appears to go to smaller scale (subnational) REDD+ projects; (iv) four distinct country groups in terms of REDD+ readiness and M&MRV status are identified; and (v) the Congo Basin has a distinct opportunity to have a specific REDD+ financing window for large-scale and more targeted national REDD+ programmes through a specific fund for the regionREDD+ voluntary database, the UN-REDD Programme and the Congo Basin Forest Fund.http://rstb.royalsocietypublishing.orghb201
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The bii4africa dataset of faunal and floral population intactness estimates across Africaâs major land uses
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on speciesâ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate âintactness scoresâ: the remaining proportion of an âintactâ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the regionâs major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems
The bii4africa dataset of faunal and floral population intactness estimates across Africaâs major land uses
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on speciesâ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate âintactness scoresâ: the remaining proportion of an âintactâ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the regionâs major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems