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Forest recession - King William's TownSkead, C J (Cuthbert John) 06 1900 (has links)
Caption "TW 10. Belt of treed vegetation surviving in an outcrop of dolerite between Buffalo River & Mount Coke, King Wms Twn. June 1961. The trees are largely Olea verrucos and Cussonia spicata which have survived by growing out from the rockiness. Otherwise surrounded by grass.”
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Forest recession - Crapkloof, King William's TownSkead, C J (Cuthbert John) January 1962 (has links)
Caption "TW 11. Desecration by the GPO. A kloof remorselessly hacked for a new telephone line 1 mile s. Kei Road, K.W.T. This is the famous Crapkloof of immortal memory. 1962.”
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Forest recession - Kologha Mt. StutterheimSkead, C J (Cuthbert John) 06 1900 (has links)
Caption "TW 10. Podocarpus latifolius growing from rocks. Top Kologha Mt. Stutterheim. June 1961.”
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Pharmacological investigation of some trees used in South African traditional medicine.Eldeen, Ibrahim Mohamed Suliman. January 2005 (has links)
South Africa is home to a wide diversity of cultural groups, all of which
utilize the flora for a variety of purposes. This is true with regard to traditional
medicine systems which are similar to those of the rest of Africa south of the
Sahara, with diviners (sangomas) and herbalists (inyangas) as the key health
providers. In addition, the Country is rich in plant diversity with some 30 000
species of flowering plants - almost one tenth of the worlds recorded higher plants.
This incorporates a large diversity of plants including trees, shrubs, herbs, bulbs
and corms.
The adverse effects of traditional medicinal plants and natural products
are not well documented in the literature. Recently, many plants used as food or in
traditional medicine have been shown to be potentially mutagenic using in vitro
assays. Thus, the scientific evaluation of traditional medicine and medicinal plants
is very important to validate claims made on safety and efficiency of such usages.
After a survey of the available ethnobotanical literature, ten trees used in
South African traditional medicine were selected. These species were: Acacia
niolotica subspecies kraussiana, Acacia sieberiana, Albizia adianthifolia,
Combretum kraussii, Faidherbia albida, Ficus sur, Prunus africana, Salix
mucronata, Terminalia sericea and Trichilia dregeana. Plant parts including leaf,
root and bark were collected from each of the selected trees (exceptions were
Albizia adianthifolia, Faidherbia albida, Terminalia sericea and Prunus africana)
and extracted using ethyl acetate, ethanol and water individually to ensure the
extraction of compounds over a wide range of polarities. The extracts (in total, 78)
were screened for antibacterial, anti-inflammatory (COX-1 and COX-2) and antiacetylcholinesterase
activities and investigated for their potential mutagenic effects
using the Ames test.
Antibacterial activity was detected using the disc-diffusion and microdilution
assays. The extracts were tested against Gram-positive bacteria: Bacillus
subtilis, Staphylococcus aureus, Micrococcus luteus and Gram-negative bacteria:
Escherichia coli and Klebsiella pneumoniae. Of the 78 different plant extracts
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tested (final amount of plant material was 1 mg per disc), 84% showed activity
against Gram-positive bacteria. From this percentage, 20% also showed activity
against Gram-negative bacteria. The best inhibition was observed with ethyl
acetate and ethanol root extracts of Terminalia sericea against both Gram-positive
and Gram-negative bacteria.
In the micro-dilution assay, 55% of the plant extracts showed minimum
inhibitory concentration (MIC) values ~ 1.56 mg/ml against Gram-positive and/or
Gram-negative bacteria. The ethyl acetate bark extract of Acacia sieberiana and
the root and bark ethyl acetate extracts of Acacia nilotica inhibited bacterial growth
of both Gram-positive and Gram-negative bacteria at concentrations ~ 0.8 mg/ml.
The aqueous leaf extracts of Acacia sieberiana had a low MIC value (0.3 mg/ml)
against Gram-negative Kleibsiella pneumoniae and the ethyl acetate extracts of the
root inhibited growth of Escherichia coli with an MIC value of 0.1 mg/ml. However,
these two extracts showed no activity in the disc-diffusion assay. The MIC values of
the neomycin (control) were 0.8 I-Ig/ml and 3.1 I-Ig/ml against Kleibsiella
pneumoniae and Escherichia coli respectively.
In the anti-inflammatory test, 70% of the plant extracts from different plant
parts (leaf, root, bark) of the tree investigated showed strong inhibition in both the
CQX-1 and CQX-2 bioassays. The CQX-2 inhibitory effects of aqueous extracts
were generally lower when compared to the organic solvent extracts. However,
water extracts of Acacia nilotica was an exception (~ 90%).
In the acetylcholinesterase inhibitory test, 21% of the plant extracts were
active at concentrations ~ 1 mg/ml using the micro-plate assay. The lowest IC50
value was 0.04 mg/ml obtained with an ethanol bark extract of Combretum kraussii.
The IC50 value of the galanthamine (positive control) was 2 I-IM.
None of the investigated plants showed any potential mutagenic effects
with Salmonella typhymurium strain TA 98 using the Ames test.
Using bioassay-guided fractionation, anolignan B was isolated from the
ethyl acetate root extract of Terminalia sericea. Antibacterial activity of anolignan B
was determined using the microdilution assay. The compound possessed activity
against both Gram-positive and Gram-negative bacteria. The lowest MIC value
(3.8 IJg/ml) was observed with Staphylococcus aureus. MIC value of the neomycin
was 1.5 IJg/ml.
Anti-inflammatory activity of anolignan B was detected using the CQX-1
and CQX-2 bioasays. The compound showed strong inhibitory activity against
CQX-1 and weaker activity against CQX-2. The ICso values were 1.5 mM and 7.5
mM with CQX-1 and CQX-2 respectively. The ICso values of indomethacin were
0.003 mM and 0.186 mM against CQX-1 and CQX-2 respectively.
There were no potential mutagenic effects showen by anolignan B against
Salmonella typhimurium strain TA 98 in the Ames test.
Isolation of anolignan B from Terminalia species and the antibacterial and
anti-inflammatory activities observed in this work have not been reported
previously and could therefore be recorded as novel biological activities for this
compound. These results also support the idea that the use of ethnobotanical data
can provide a valuable short cut by indicating plants with specific uses which might
likely be sources of biologically active chemicals. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Preserving treesSkead, C J (Cuthbert John) 19 May 1959 (has links)
Article written by C. J. Skead to the East London Daily Dispatch (dated 19 May 1959), bringing attention to the deforestation of the Fort Grey forest by Mr C Miles Warren (MP). The article is acompanied by a harndwitten note stating "Mr C Miles Warren, M.P. had the contract for removing the forest and did very well out of it, especially with box-wood!! Hence the letter which would have [illegible] his consumers".
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Bush recession - Dubu Drift, Keiskamma RiverSkead, C J (Cuthbert John) January 1962 (has links)
Caption "Lone Scotia species tree left standing when all other bush destroyed above Dubu Drift, on the Keiskamma R. southern King William’s Town district. Even the veld is destroyed. Ca. 1962"
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The influence of structure, density and direct use benefits on the harvesting of trees in the rural village of Pikoi, Eastern Cape, South AfricaMotinyane, Teboho R January 2002 (has links)
The people of Pikoli in the Peddie district of the Eastern Cape are mostly unemployed and earn most of their income from old-age allowances. The place is remote and 'modern' amenities such as paraffin and petroleum gas are expensive. Electricity and transport are unavailable. There is heavy reliance on woody plants for fuel and for materials for construction and fencing and to some extent medicinal and ritual uses. Indigenous trees in this rural area are threatened by over-utilisation and the absence of clear government management policies. The over-utilisation of these resources is leading to deforestation. It was proposed at the beginning of this study that people who harvest trees cause similar results to the piosphere effect caused by the herbivores on the rangeland. Ecological-economic analysis was performed to find a common ground between the people's income and needs so that effective sustainable management strategies can be developed. A combination of semi-structured interviews, direct observations and ecological surveys were used to gather information about: Tree species used, and for what purpose in Pikoli; Individual tree species preference by inhabitants; Change in tree density in response to changes in utilisation intensity at varying distances away from the village; The local direct use benefits inhabitants derive from utilising indigenous tree resources. The study showed that the people of Pikoli use a variety of 23 indigenous trees and that they have marked preferences regarding the tree species they use for fuelwood and construction purposes. Although Ptaeroxylon obliquum is a highly preferred species for fuelwood and construction, its popularity can also be linked to its high relative abundance in this area. Other species such Maytenus undata and Pappea capensis are also highly preferred although they are harvested at much greater distances from thecentre of the village. Change in individual tree density in response to changes in utilisation intensity at varying distances away from the village showed clearly that a piosphere effect also applies to human harvesting. The average number of individual trees closer (1 200 m) to the village centre was 2 trees per 100 m², and their numbers increase to approximately 35 trees per 100 m² at a distance of about 3 000 m from the village centre. The study reports on the direct use benefits derived by the people of Pikoli from harvesting tree resources. The average total net value of trees harvested for fuelwood was R4089.09 (US$ 359.01) per household per annum. The value of tree resources harvested represents a large percentage of average households' annual income. Therefore, the economic benefits households derive from utilising tree resources are high. Indigenous tree resource use in this rural village seems to be unsustainable and the inhabitants seem to be aware of it. However, they have few alternatives. Their economic conditions do not allow them to afford alternative resources available in the formal market.
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Economic evaluation of possible loss of Prosopis pods as a result of biological control in the Northern Cape Province, South AfricaNqobizitha, Dube January 2009 (has links)
Species of Prosopis (Mimosaceae), or mesquite, are native to the Americas and introduced in South Africa as agro forestry trees to provide wood, fodder and shade in the late 1800s. In the Northern Cape Province, these trees have been particularly used for their pods by local farmers and local industry. However due to Prosopis’ ability to spread rapidly there has been increasing pressure to step up control of the tree. Due to the costs associated with most control methods biological control has been singled out as the most viable control method worth pursuing. This thesis attempts to explain and shed light on the effects that increased biological control of Prosopis would have on the farming community and Prosopis based businesses in the area. Two hypothetical scenarios were used, the first being a possible 50% reduction in available pods and the other a possible 100% reduction. In an effort to explain these effects data was collected from a series of collection activities in the form of a pilot study and two unique questionnaire surveys. Twenty-seven farmers and one Prosopis based business were interviewed at random with the data analysed and documented. Results showed that the business community is the main user of pods incurring crippling losses in the event of a 50% or 100% decrease in available pods. Using control costs from working for water De Aar long term costs of the presence of Prosopis were estimated and compared to the estimated provincial cost of losing pods giving a cost comparison ratio of (α)270 million : Y(N(15.7million)). Only 48% of the respondents valued pods and 11% had traded in pods, the top concern resulting from the invasion was the loss of underground water. With a 50% decline in available pods, all respondents indicated unchanged effects. However empirical results showed that with a 100% decline in pods estimate losses of R 5 818 per farm are expected. The cost comparison ratio showing the losses farmers bore with Prosopis in the area and the losses they would suffer with a 100% decline in pods was R11 389 + (K): R5 818. In light of the empirical results, policy recommendations that support the introduction of more effective biological control agents have been made with areas for further research identified and discussed.
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Comparative impact of invasive alien trees and vineyards on arthropod diversity in the Cape floristic region, Western CapeMagoba, Rembuluwani Norman Nicholas 12 1900 (has links)
Thesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Invasive alien trees (IATs) and agriculture are rapidly altering the capacity of ecosystems to provide a variety of essential services, with decreasing habitat quality having an adverse effect on arthropod biodiversity. Although both agricultural intensification and IATs have an impact on ecosystems, it is unclear which of these two is currently the most severe. Here I compare the influences of vineyards and IATs on arthropod diversity in the Cape Floristic Region (CFR) from two perspectives. Firstly, insect diversity from four different vegetation types (native fynbos, IATs, cleared invasive alien trees (CIATs) and vineyards), and their ecotones were assessed. Secondly, soil compaction in the different vegetation types was assessed and compared to determine how soil compaction relates to arthropod species richness and abundance.
Surface-active arthropods were used for these evaluations, as they were considered to be the most abundant, yet sensitive groups for these comparative assessments. Pitfall trapping, which has been widely used for such comparative studies, was the method of choice. Additionally, as a result of incidental wildfires at some of the study sites (IATs and fynbos vegetation), it was decided opportunistically to assess recovery of arthropod diversity following the impact of fire.
The results categorically indicate that IATs had by far the most significant impact, in comparison with vineyards, in reducing arthropod diversity and changing assemblage composition. Both IATs and vineyards, not surprisingly, supported lower arthropod diversity compared to fynbos, while CIATs supported arthropod species richness comparable to that of fynbos. However, different invertebrate species responded differently to IAT invasion, with some species even adapted to conditions in IAT patches. Environmental factors such as leaf litter and soil compaction were strongly correlated with arthropod species richness. However, other factors, such as soil moisture content, were not correlated with species richness, despite varying significantly between different vegetation types. IATs were found to reduce soil compaction, while vineyards increased soil compaction.
The ecotone between adjacent land-use types was important for sustaining high arthropod species richness, particularly for the CIATs/fynbos ecotone, followed by the interface between CIATs/vineyard and vineyard/fynbos. Some species even preferred ecotones.
Surface-active invertebrate species richness declined substantially immediately after fire in both IATs and fynbos. Nevertheless, recovery was rapid, with some species recolonizing or re-establishing within three months. Indeed, both species richness and abundance were high following fire. Fire had no significant impact on arthropod assemblage within IATs, despite having a serious impact in the fynbos where a different arthropod assemblage was observed after fire. The recovery of the historic assemblages may be dependent on both the pre-fire composition of the habitat and its adjacent vegetation.
Effective co-operation among conservation biologists, farmers, and landowners to actively plan the future of CFR landscape biodiversity is required. / AFRIKAANSE OPSOMMING: Indringer uitheemse bome (IUB) en landbou bedrywighede is vinnig besig om die kapasiteit van ekosisteme vir die voorsiening van „n verskeidenheid van noodsaaklike dienste, met „n afname in habitatkwaliteit en „n nadelige uitwerking op artropood biodiversiteit, te verander. Alhoewel beide, landbou intensifikasie en IUB‟s, ‟n impak op ekosisteme uitoefen, is dit onduidelik watter van hierdie twee huidig die mees ernstige een is. In hierdie studie vergelyk ek die invloed van wingerde en IUB‟s op artropood diversiteit in die Kaapse Floristiese Streek (KFS) vanuit twee perspektiewe. Eerstens, insekdiversiteit van vier verskillende vegetasietipes (natuurlike fynbos, IUB‟s, verwyderde indringer uitheemse bome (VIUB‟s) en wingerde) en hulle ekotone is bepaal. Tweedens, is grondverdigting in en van die verskillende vegetasietipes ondersoek en vergelyk om te bepaal hoe grondverdigting verband hou met artropood spesies rykheid en volopheid.
Oppervlak-aktiewe artropode is vir hierdie bepalings gebruik aangesien hulle beskou word as die mees volopste, maar ook mees sensitiewe groepe vir hierdie vergelykende bepalings. Pitvalvangste, wat alom gebruik word vir sulke vergelykende studies, was die verkose werkswyse. Bykomend, as gevolg van onbeplande veldbrande in sommige studie gebiede (IUB‟s en fynbos plantegroei), is oppertunisties van die geleentheid gebruik gemaak om die herstel van artropood diversiteit na die impak van brand te bepaal.
Die resultate toon duidelik aan dat IUB‟s, in vergelyking met wingerde, by verre die mees beduidende impak gehad het deur ‟n verlaging van artropood diversiteit en veranderende groeperingssamestellings. Beide, IUB‟s en wingerde, het, nie onverwags nie, in vergelyking met fynbos, laer artropood diversiteit ondersteun, terwyl VIUB‟s artropood spesies verskeidenheid, vergelykbaar met dié van fynbos, ondersteun het. Verskillende invertebrate spesies het egter verskillend gereageer op IUB indringing, en sommige spesies het selfs by toestande in IUB kolle aangepas. Omgewingsfaktore soos blaarafval en grondverdigting was sterk gekorrelleer met artropood spesies rykheid. Ander faktore, soos grondvoginhoud, was egter nie in ooreenstemming met spesies rykheid nie, ten spyte van ‟n beduidende wisseling tussen verskillende vegetasietipes. IUB‟s het grondverdigting verminder, terwyl by wingerde grondverdigting toegeneem het. Die ekotone tussen aanliggende grondgebruike was belangrik om hoë artropood spesies rykheid, veral by die VIUB‟s/fynbos ekotoon, gevolg deur die kontaksones tussen VIUB‟s/wingerd en wingerd/fynbos, te onderhou. Sommige spesies het selfs ekotone verkies.
Oppervlak-aktiewe invertebraat spesies rykheid het onmiddelik na brand in beide, IUB‟s en fynbos, wesenlik afgeneem. Tog was herstel vinnig, met sekere spesies wat binne drie maande teruggekeer of hulle hervestig het. Inderdaad was beide, spesies rykheid en volopheid, hoog na ‟n brand. Brand het geen noemenswaardige invloed op artropood groeperings binne IUB‟s gehad nie, ten spyte van ‟n ernstige impak in fynbos waar ‟n verskillende artropood groepering na ‟n brand waargeneem is. Die herstel van die historiese groeperings van beide, die voor-brand samestelling van die habitat en sy aangrensende plantegroei, mag afhanklik wees.
Effektiewe en aktiewe samewerking tussen bewaringsbioloë, boere, en grondeienaars om die toekoms van KFS landskap biodiversiteit te beplan, word benodig.
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On the development and application of indirect site indexes based on edaphoclimatic variables for commercial forestry in South AfricaEsler, William Kevin 03 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Site Index is used extensively in modern commercial forestry both as an indicator of current and future site potential, but also as a means of site comparison. The concept is deeply embedded into current forest planning processes, and without it empirical growth and yield modelling would not function in its present form. Most commercial forestry companies in South Africa currently spend hundreds of thousands of Rand annually collecting growth stock data via inventory, but spend little or no money on the default compartment data (specifically Site Index) which is used to estimate over 90% of the product volumes in their long term plans. A need exists to construct reliable methods to determine Site Index for sites which have not been physically measured (the socalled "default", or indirect Site Index). Most previous attempts to model Site Index have used multiple linear regression as the model, alternative methods have been explored in this thesis: Regression tree analysis, random forest analysis, hybrid or model trees, multiple linear regression, and multiple linear regression using regression trees to identify the variables. Regression tree analysis proves to be ideally suited to this type of data, and a generic model with only three site variables was able to capture 49.44 % of the variation in Site Index. Further localisation of the model could prove to be commercially useful.
One of the key assumptions associated with Site Index, that it is unaffected by initial planting density, was tested using linear mixed effects modelling. The results show that there may well be role played by initial stocking in some species (notably E. dunnii and E. nitens), and that further work may be warranted. It was also shown that early measurement of dominant height results in poor estimates of Site Index, which will have a direct impact on inventory policies and on data to be included in Site Index modelling studies.
This thesis is divided into six chapters: Chapter 1 contains a description of the concept of Site Index and it's origins, as well as, how the concept is used within the current forest planning processes. Chapter 2 contains an analysis on the influence of initial planted density on the estimate of Site Index. Chapter 3 explores the question of whether the age at which dominant height is measured has any effect on the quality of Site Index estimates. Chapter 4 looks at various modelling methodologies and compares the resultant models. Chapter 5 contains conclusions and recommendations for further study, and finally Chapter 6 discusses how any new Site Index model will effect the current planning protocol. / AFRIKAANSE OPSOMMING: Hedendaagse kommersiële bosbou gebruik groeiplek indeks (Site Index) as 'n aanduiding van huidige en toekomstige groeiplek moontlikhede, asook 'n metode om groeiplekke te vergelyk. Hierdie beginsel is diep gewortel in bestaande beplanningsprosesse en daarsonder kan empiriese groeien opbrengsmodelle nie in hul huidige vorm funksioneer nie. SuidAfrikaanse bosboumaatskappye bestee jaarliks groot bedrae geld aan die versameling van groeivoorraad data deur middel van opnames, maar weinig of geen geld word aangewend vir die insameling van ongemete vak data (veral groeiplek indeks) nie. Ongemete vak data word gebuik om meer as 90% van die produksie volume te beraam in langtermyn beplaning. 'n Behoefte bestaan om betroubare metodes te ontwikkel om groeiplek indeks te bereken vir groeiplekke wat nog nie opgemeet is nie. Die meeste vorige pogings om groeiplek indeks te beraam het meervoudige linêre regressie as model gebruik. Alternatiewe metodes is ondersoek; naamlik regressieboom analise, ewekansige woud analise, hibriedeof modelbome, meervoudige linêre regressie en meervoudige linêre regressie waarin die veranderlike faktore bepaal is deur regressiebome. Regressieboom analise blyk geskik te wees vir hierdie tipe data en 'n veralgemeende model met slegs drie groeiplek veranderlikes dek 49.44 % van die variasie in groeiplek indeks. Verdere lokalisering van die model kan dus van kommersiële waarde wees.
'n Sleutel aanname is gemaak dat aanvanklike plantdigtheid nie 'n invloed op groeiplek indeks het nie. Hierdie aanname is getoets deur linêre gemengde uitwerkings modelle. Die toetsuitslag dui op 'n moontlikheid dat plantdigtheid wel 'n invloed het op sommige spesies (vernaamlik E. dunnii en E. nitens) en verdere navorsing kan daarom geregverdig word. Dit is ook bewys dat metings van jonger bome vir dominante hoogtes gee aanleiding tot swak beramings van groeiplek indekse. Gevolglik sal hierdie toestsuitslag groeivoorraad opname beleid, asook die data wat vir groeiplek indeks modellering gebruik word, beïnvloed.
Hierdie tesis word in ses hoofstukke onderverdeel. Hoofstuk een bevat 'n beskrywing van die beginsel van groeiplek indeks, die oorsprong daarvan, asook hoe die beginsel tans in huidige bosbou beplannings prosesse toegepas word. Hoofstuk twee bestaan uit ń ontleding van die invloed van aanvanklike plantdigtheid op die beraming van groeplek indeks. In hoofstuk drie word ondersoek wat die moontlike invloed is van die ouderdom waarop metings vir dominante hoogte geneem word, op die kwaliteit van groeplek indeks beramings het. Hoofstuk vier verken verskeie modelle metodologieë en vergelyk die uitslaggewende modelle. Hoofstuk vyf bevat gevolgtrekkings en voorstelle vir verdere studies. Afsluitend, is hoofstuk ses ń bespreking van hoe enige nuwe groeiplek indeks modelle die huidige beplannings protokol kan beïnvloed.
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