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The restoration of scrub invaded chalk grassland : a comparison of scrub clearance techniques (manual clearance and livestock browsing)Oliver, Pauline January 2004 (has links)
The best way of dealing with the restoration of chalk grassland encroached by scrub is unclear and the subject of many debates. The traditional method is to clear the scrub primarily by manual methods of cutting the scrub and after clearance the land is left to regenerate naturally. More recently the development of using livestock to browse and gradually reduce the scrub is thought to be an alternative. However the effectiveness of either of these methods (Manual clearance or Livestock browsing) is questioned by many and some believe that once scrub has encroached, the soils beneath this will become too enriched to be able to support a chalk grassland flora. This thesis aimed to provide a better understanding by undertaking a five year investigative trial of the two restoration methods and comparing and examining the ability of these to successfully restore a chalk grassland habitat. To undertake this both methods were trailed on scrub invaded chalk grassland and changes in vascular plants and invertebrates were monitored throughout trial period. Areas of nonintervention scrub were also included to act as controls. Successful restoration was assessed by comparing the results from the trials with measurable vascular plant restoration targets that were identified and set from known chalk grasslands in favourable condition. Soil fertility within the trial area was also examined to determine if the soils were considered to fertile to support a chalk grassland flora and costs and practicalities of using ether method were recorded throughout enabling these to be taken into account. The results showed that differences in both the species richness and composition of vascular plants and spider and beetles invertebrate species occurred. Soil fertility was found to suitable to support chalk grassland plants and vascular plants species were identified as moving away from those associated with scrub into those associated with chalk grasslands. It was observed however that on the areas trailed using Manual clearance, an initial flush of ruderal species occurred after clearance, it was therefore concluded that for Manual clearance to be successful continued restoration management is required if these species are to be controlled. It was also observed that the areas trailed using Manual clearance were moving towards successful restoration quicker those trailed using Livestock browsing thus indicating that the rate of change is more gradual using Livestock browsing. This rate of change was also found to occur within the invertebrate beetles and spider communities. Species richness within the spider communities however decreased on the areas manually cleared. Costs of using the restoration methods showed that the use of Livestock browsing was five times more costly that using Manual clearance. However it was found that majority of Livestock browsing costs incurred through welfare and husbandry of the stock. Restoration using Manual clearance also involved using livestock once scrub had been cleared however the costs of these were born by a local grazier and thus did not show as a cost of restoration. It was concluded that if a grazier is not found then these costs would be incurred. Overall it is concluded that both Livestock browsing and Manual clearance have the ability to successfully restore a chalk grassland community but that this must be viewed as a long term objective. Restoration management is critical to continue after clearance until restoration targets have been met.
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Factors determining location and species composition of wet grasslands in Southwest England /Soest, Francien van. January 2005 (has links)
Univ., Diss.--Plymouth, 2002.
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Community-level effects of fragmentation of the afromontane grassland in the escarpment region of Mpumalanga, South AfricaKamffer, Dewald. January 2004 (has links)
Thesis (M.S.)--University of Pretoria, 2004. / Title from PDF t.p. (viewed Mar. 10, 2005). Includes bibliographical references.
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Biodiversity of ants (Hymenoptera: Formicidae) in restored grasslands of different agesPhipps, Sarah J. January 2006 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 27, 2007) Includes bibliographical references.
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A vegetation survey and mapping of the woodbush granite grassland in the Limpopo Province, South AfricaMatjie, Mapula Rose January 2019 (has links)
Thesis (M. Sc. (Botany)) -- University of Limpopo, 2019 / The Woodbush Granite Grassland (WGG) is the most threatened vegetation type in Limpopo Province of South Africa. However, it has a high conservation value, because few examples of this vegetation type remain in southern Africa. Unfortunately, a large part of it is not formally conserved, making this the vegetation type most urgently in need of conservation.
The study aimed at mapping transformation of the WGG, identifying species of conservation importance, and providing a management plan required for maintenance of the WGG. The objectives of the study included compiling a transformation map for the WGG, which also involved describing the remaining patches of the WGG that are in a natural or near-natural state. It also provides information on species of conservation importance, medicinal plants and threats to the WGG.
On the four main study sites (Iron Crown Grassland, Haenertsburg Grassland, Ebenezer Dam Nature Reserve Grassland, and Ebenezer Dam Perimeter Grassland), quadratic plots were randomly set with a size of 25 x 25 m, and subplots of 1 x 1 m. Vegetation mapping was done during summer and winter. At each plot data was collected on all plant species occurring within the quadrat. A cover score was assigned to each plant species. A modified Braun-Blanquet data collection sheet was employed to obtain baseline data. For transformation mapping GeoTerra Image (GTI), land cover data were extracted for the WGG, using the modelled boundary as a mask, with 5 categories of transformation defined.
Of the surveyed sites, the Ebenezer Dam Nature Reserve Grassland has the highest number of species, while the Haenertsburg Grassland contained the most endemic species of conservation importance. Rare species such as the Aloe zebrina, which does not occur in any formally protected area, and medicinal plants such as Athrixia phylicoides, occur on the WGG. All sites have importance with regard to WGG conservation. Identified threats include the spread of alien invasive plants, uncontrolled collection of medicinal plants, urban development, and poorly timed anthropogenic fire.
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The WGG underwent transformation to other land classes. Grassland clearing for plantations and cultivation were the main causal factors behind the observed WGG losses, with a total of 55.25% transformed. Transformation by afforestation is considered irreversible.
It is concluded that the WGG is of conservation importance, and that some of it has been transformed to exotic timber plantations. The grassland is under various threats; therefore it is recommended that: (1) The proposed management plan provided in this study be adopted, (2) further research on the WGG be done on medicinal plants, (3) phytosociological and floristic studies be conducted and, (4) the effects of fire and alien invasive plant species on the grassland be investigated.
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Comparison of IKONOS derived vegetation index and LiDar derived canopy height model for grassland managementParker, Gary. Dong, Pinliang, January 2009 (has links)
Thesis (M.S.)--University of North Texas, Dec., 2009. / Title from title page display. Includes bibliographical references.
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Attitudes and behaviour of landholders towards the conservation of Overberg Coastal Renosterveld, a threatened vegetation type in the Cape Floral KingdomWinter, Susan Jean 12 1900 (has links)
Thesis (MScConsEcol) -- Stellenbosch University, 2003. / ENGLISH ABSTRACT: This thesis describes the findings of a survey to investigate the attitudes and behaviour of private landholders
towards the conservation of Overberg Coastal Renosterveld, a highly endangered grassy-shrubland of the
Cape Floral Region (CFR) lowlands, now 94% transformed. Personal interviews were conducted with 36
farmers in the Overberg region of the Western Cape, by administering a questionnaire. The following aspects
were quantitatively described using the Statistical Package for Social Scientists (SPSS): Renosterveld
management and utilisation behaviour, perceived value of Overberg Coastal Renosterveld; landholder
knowledge of its conservation importance and willingness to conserve it. Attitudes towards incentives for
conservation; conservancies; and the provincial conservation authorities were also investigated. Willingness
to conserve was explored further using SPSS cross-tabulation analyses. It was found that farmers who were
more willing to conserve were younger, did not necessarily have a better education, and owned larger farms
(> 500 ha) with a greater amount of remnant renosterveld (> 300 ha) than farmers less willing to conserve.
Attitudes towards Overberg Coastal Renosterveld were largely negative, due to certain associated plants and
animals which are problems for farmers, and because it is not economically advantageous to retain it.
However, provision of incentives (of which assistance with fencing and land management was most
attractive) and increased extension support will provide practical positive inducements for conservation.
There is also a need for more landholder education regarding the scarcity of coastal renosterveld to prevent
transformation of remaining fragments. The second component of the study aimed to construct a user-friendly index to measure the conservation
attitudes of landholders towards conserving Overberg Coastal Renosterveld. An interative item analysis was
executed on the data, using Spearman Rank Order correlations and Cronbach's Alpha. Results yielded an
index with two dimensions and a Cronbach Alpha co-efficient of 0.67. The dimensions or components of
conservation attitude towards renosterveld included: (i) a landholders' perception of the perceived benefit of
Overberg Coastal Renosterveld; and (ii) their willingness to conserve it. The mean conservation attitude
score was 0.6 (± 0.03), indicating that landholder attitudes were generally sympathetic towards renosterveld
conservation. This suggests that while many landholders do not place a high value on Overberg Coastal
Renosterveld due to its low agricultural value, their willingness to conserve it is in some cases higher than
expected, which possibly explains the above-average mean conservation attitude score. An analysis of
variance showed that the following variables were significantly, positively correlated with conservation
attitude: (i) area of Overberg Coastal Renosterveld; (ii) landholder environmental group membership status;
(iii) presence of ecotourism activities on the property; and (iv) how long the property had been in the
owner's family. The intended application of the index is that index scores (amenable for use in a
Geographical Information System database) can assist conservation practitioners in deciding where resources should be allocated, on the assumption that high-scoring individuals are more likely to want to take part in
conservation initiatives. / AFRIKAANSE OPSOMMING: Hierdie proefskrif beskryf die bevindings van 'n opname waarin die houdings en gedrag van private
grondeienaars ten opsigte van Overberg Kustelike Renosterveld ondersoek word. Altesaam 94% van die
oorspronklike renosterveld, 'n hoogs bedreigde, grasagtige struikveld in die laaglande van die Kaapse
Planteryk (KPR) , is reeds getransformeer en verander. Persoonlike onderhoude is met 36 boere in die
Overbergstreek van die Wes-Kaap gevoer en 'n vraelys is aan hulle gestel. Die "Statistical Package for
Social Scientists" (SPSS) is gebruik om die volgende aspekte kwantitatief te beskryf: die bestuur en
benutting van Overberg Kustelike Renosterveld; die waarde wat toegeskryf word aan hierdie renosterveld;
asook grondeienaars se kennis oor die bewaringsbelang van Overberg Kustelike Renosterveld en hul
bereidwilligheid om dit te bewaar. Houdings jeens aansporingsmiddele om bewaring te bevorder, bewareas
en die provinsiale bewaringsowerhede is ook ondersoek. Private grondeienaars se bereidwilligheid om
betrokke te raak by bewaringswerk is verder ondersoek deur gebruik te maak van die SPSS-kruistabelleringsanalise.
In vergelyking met boere wat nie bewaring ondersteun nie, is gevind dat die meer
bewaringsgesinde boere jonger is, nie noodwendig 'n beter opvoeding het nie, en groter plase (>500 ha) besit
waarop meer brokkies oorblywende Overberg Kustelike Renosterveld (>300 ha) gevind word. Grondeienaars
se houding jeens Overberg Kustelike Renosterveld was grootliks negatief. Dit is as gevolg van sekere
verwante plante en diere wat deur boere as probleme ervaar word, en omdat dit nie ekonomies lewensvatbaar
is om renosterveld te behou nie. Die beskikbaarheidstelling van aansporingsmiddele (waarvan hulpverlening
met omheinings en grondbestuur die aantreklikste was), en 'n toename in landbou-voorligting is egter
praktiese en positiewe dryfvere wat bewaring kan bevorder. Daar is ook 'n behoefte vir meer opvoeding van
grondeienaars oor aspekte soos die skaarsheid van Overberg Kustelike Renosterveld, sodat die verdere
transformasie van oorblywende fragmente voorkom kan word.
Die tweede gedeelte van die studie was daarop gemik om 'n gebruikersvriendelike indeks te ontwikkel
waarmee die bewaringsgesindheid van grondeienaars teenoor die bewaring van renosterveld gemeet kan
word. Deur gebruik te maak van Spearman se rangorde-korrelasies en Cronbach se Alpha is die data aan 'n
herhalende item-analise onderwerp. Die resultate het 'n indeks met twee dimensies en 'n Cronbach Alpha-koëffisiënt
van 0.67 gelewer. Die dimensies of komponente van bewaringsgesindheid jeens renosterveld het
onder meer ingesluit: i) 'n grondeienaar se opvatting oor die moontlike voordeel van Overberg Kustelike
Renosterveld en ii) sy/haar bereidwilligheid om dit bewaar. Die gemiddelde telling vir bewaringsgesindheid
was 0.6 (± 0.03), wat in die algemeen 'n simpatieke houding jeens die bewaring van Overberg Kustelike Renosterveld onder grondeienaars aandui. Hiervolgens blyk dit dat alhoewel heelwat grondeienaars weens
die lae landbouwaarde van renosterveld nie 'n hoë waarde op hierdie plantegroeitipe plaas nie, hulle
bereidwilligheid om dit te bewaar soms verwagtinge oortref. Dit is dalk 'n moontlike verklaring vir die bogemiddelde
gemiddelde bewaringsgesindheidtelling. 'n Variansie-analise het 'n noemenswaardige, positiewe
korrelasie met bewaringsgesindheid ten opsigte van die volgende veranderlikes getoon: i) area van Overberg
Kustelike Renosterveld; ii) die grondeienaar se moontlike lidmaatskap van 'n bewaringsgroep; iii) die
teenwoordigheid van ekotoerisme-bedrywighede op die eiendom; en iv) die tydperk wat die eiendom al in
besit van die grondeienaar se familie is. Die voorgestelde gebruik van die indeks is toepaslik omdat die
indeks-tellings (wat vir gebruik in 'n Geografiese Inligtingstelsel databasis aangepas kan word) bewaringslui
kan help met besluite random die toekenning van hulpbronne. Die aanname is dat individuele grondeienaars
wie hoë tellings aangeteken het, met alle waarskynlikheid meer geredelik aan bewaringsinisiatiewe sal wil
deelneem.
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An investigation into the problems of ineffective control of invasive plants in selected areas of South Africa : a case study of Campuloclinium macrocephalum (pompom weed)Mashiloane, William Tlokotse 09 1900 (has links)
Interference of natural environment by invasive plants is a global concern. In South Africa and in particular Gauteng Province, interference of natural land by invasive plants that originated from other countries has been an endemic problem. These invasive plants pose a threat to biodiversity as a result of its wild and wide dispersion rate where it spreads into neighbouring Provinces such as Mpumalanga, Limpopo, North West and the Free State. Pompom weed is aggressive to control and can spread by means of both wind and water. This research project investigates problems associated with ineffective control of invasive plants in general and pompom weed in particular. State organs, Non Governmental Organisations (NGOs) and farming communities were identified as relevant respondents in this study. Three hundred (300) validated questionnaires were distributed to these stakeholders and 286 were adequately completed and received. These were analysed and the data interpreted. Results obtained showed that lack of coordination and teamwork from all stakeholders are responsible for ineffective control of invasive plants in the country. The use of biological control was recommended for the control and eradication of the invasive plants. / Environmental Sciences / M.A. (Environmental Management)
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Remote sensing of leaf area index in Savannah grass using inversion of radiative transfer model on Landsat 8 imagery: case study Mpumalanga, South AfricaMasemola, Cecilia Ramakgahlele 03 1900 (has links)
Savannahs regulate an agro-ecosystem crucial for the production of domestic livestock, one of the main sources of income worldwide as well as in South African rural communities. Nevertheless, globally these ecosystem functions are threatened by intense human exploitation, inappropriate land use and environmental changes. Leaf area index (LAI) defined as one half the total green leaf area per unit ground surface area, is an inventory of the plant green leaves that defines the actual size of the interface between the vegetation and the atmosphere. Thus, LAI spatial data could serve as an indicator of rangeland productivity. Consequently, the accurate and rapid estimation of LAI is a key requirement for farmers and policy makers to devise sustainable management strategies for rangeland resources.
In this study, the main focus was to assess the utility and the accuracy of the PROSAILH radiative transfer model (RTM) to estimate LAI in the South African rangeland on the recently launched Landsat 8 sensor data. The Landsat 8 sensor has been a promising sensor for estimating grassland LAI as compared to its predecessors Landsat 5 to 7 sensors because of its increased radiometric resolution. For this purpose, two PROSAIL inversion methods and semi- empirical methods such as Normalized difference vegetation index (NDVI) were utilized to estimate LAI. The results showed that physically based approaches surpassed empirical approach with highest accuracy yielded by artificial neural network (ANN) inversion approach (RMSE=0.138), in contrast to the Look-Up Table (LUT) approach (RMSE=0.265). In conclusion, the results of this study proved that PROSAIL RTM approach on Landsat 8 data could be utilized to accurately estimate LAI at regional scale which could aid in rapid assessment and monitoring of the rangeland resources. / Environmental Sciences / M. Sc. (Environmental Science)
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The mesofilter concept and biodiversity conservation in Afro-montane grasslandsCrous, Casparus Johannes 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Conservation planners use many traditional biodiversity conservation tools to help alleviate
the global biodiversity crisis. However, ongoing biodiversity loss has stimulated the
development of new and improved methods for conserving biodiversity. One such new
conservation tool is the mesofilter approach. Mesofilters are biotic or abiotic ecosystem
elements which are critical to the well-being of many species, and therefore could help to
explain spatial heterogeneity in species across a landscape. It is also complementary to more
traditionally used concepts such as coarse- and fine-filter conservation concepts. Applying the
mesofilter approach in protected area, conservancy, or land-sparing design and management,
could optimise biodiversity conservation in a rapidly developing world. For example, the
timber industry has been pro-active in its approach to lessen biodiversity loss, by optimising
design and management of the plantation matrix through ecological networks. Here, I explore
the use of mesofilters within highly threatened remnant Afro-montane grasslands in
KwaZulu-Natal, South Africa, to optimise biodiversity conservation planning for such
landscapes. As per anecdotal evidence, I used rockiness in the landscape as a possible driver
of species richness and species assemblage variability at the meso-scale, using a multi-taxon
and multi-trophic approach. In this montane landscape, I also examined the effect of elevation
on spatial heterogeneity of taxa. I further examined the functional responses of taxa to
rockiness in the landscape. Rockiness in the landscape significantly influenced the species
richness and assemblage structure of three key grassland taxa: flora, butterflies, and
grasshoppers. I showed that for plants, this response was due to growth forms such as
geophytes and perennial grasses that were more closely associated with rockiness, and
therefore the main contributors to observed differences in the dispersion patterns of flora.
Grasshoppers were not necessarily responding to higher rock exposure per se, but rather
towards the environmental conditions created by rockiness within the landscape, such as
lower vegetation density. For butterflies, certain behavioural traits, such as resting, territorial
behaviour and/or mate-locating behaviour, were more typical in areas of higher rock
exposure. This suggested that rocks are a definite habitat resource to certain butterflies.
Overall, this finding where an abiotic surrogate is representative of key taxa in an ecosystem
is interesting, as cross-taxon surrogacy has been shown to be stronger than surrogates based
on environmental data. Furthermore, taxa responded functionally to rockiness in the
landscape. This thesis therefore supports the idea that environmental surrogates are indeed
useful for biodiversity conservation planning. Furthermore, ecosystems can potentially have many attributes or features that would be of conservation interest, and delineating a set of
mesofilters is a useful way of expressing particular attributes to be used in wildlife
conservation evaluation. The concept of the mesofilter as a practical biodiversity conservation
tool is therefore validated here. I also argue the importance of habitat heterogeneity for
biodiversity conservation planning in this montane grassland landscape. The potential for
optimising the design of landscape configurations such as ecological networks, through
information obtained from the mesofilter, is emphasised. We can safely add another tool in
the biodiversity conservation toolbox of this Afro-montane grassland ecosystem. / AFRIKAANSE OPSOMMING: Bewaringbeplanners gebruik tans baie tradisionele biodiversiteit-bewarings metodes om die
huidige biodiversiteits krisis te help verlig. Tog, die huidige voortdurende verliese in
biodiversiteit wêreldwyd, vra na nuwer en verbeterde metodes van biodiversiteit-bewaring.
Een so ‘n nuwe bewaring metode, is die mesofilter. Mesofilters is biotiese of abiotiese
ekosisteem elemente wat kritiek is tot die welstand van spesies, en daarom veral waardevol is
om variasie in spesies verspreiding in ‘n landskap te help verduidelik. Daarby is die
mesofilter konsep ook komplementêr tot meer tradisioneel gebruike bewaringskonsepte, soos
fyn-filter en breë-filter konsepte. Deur die mesofilter benadering toe te pas in die ontwerp en
bestuur van beskermde areas, bewaareas, of land-spaar initiatiewe, kan ons biodiversiteitbewaring
in ‘n vining ontwikkelende wêreld optimaliseer. Byvoorbeeld, die bosbou industrie
is pro-aktief in hul benadering om biodiversiteit verliese te verminder, deur optimalisering
van die ontwerp en bestuur van ekologiese netwerke in die plantasiematriks. In hierdie tesis,
ondersoek ek die gebruik van mesofilters in hoogs bedreigde oorblyfels Afrikaberg grasvelde
in KwaZulu-Natal, Suid-Afrika, om die bewaringsbeplanning van dié gebiede te optimaliseer.
Vanaf anekdotiese bewyse, het ek spesifiek gebruik gemaak van klipperigheid in die landskap
as ‘n moontlike drywer van spesies-rykheid en spesies-samestelling variasie by ‘n meso-skaal,
deur ‘n multi-takson en multi-trofiese benadering. In hierdie berglandskap, het ek ook die
effek van hoogte bo seevlak op ruimtelike verspreiding van taksa bestudeer. Verder het ek
ook gekyk na die funksionele reaksie van taksa tot klipperigheid in die landskap.
Klipperigheid in die landskap het ‘n beduidende invloed gehad op spesies-rykheid en spesiessamestelling
van drie sleutel grasveld taksa: plante, skoenlappers, en springkane. Ek wys dat
vir plante, hierdie reaksie as gevolg was van spesifieke plantgroeivorme, soos bolplante en
meerjarige grasse, se noue verband met klipperigheid, en daarom, dat hierdie groepe die hoof
bydraers is tot gesiene variasie in plantspesies verspreiding in die landskap. Vir springkane,
was hierdie reaksie nie noodwendig omdat hulle die klippe self gebruik het nie, maar meer as
gevolg van die omgewingskondisies geskep deur verhoogde klipperigheid in die landskap,
soos laer plantegroei digtheid. Vir skoenlappers, was hierdie reaksie tot klippe as gevolg van
sekere gedragskaraktereienskappe, soos rus op klippe, gebied beskerming en/of paarmaat
soektog, wat tipies meer gesien was in klipperige omgewings. Dit dui daarop dat klippe ‘n
definitiewe habitat hulpbron is vir sekere skoenlappers. Oor die algemeen is hierdie
bevinding, waar abiotiese surrogate verteenwoordig is van drie sleutel taksa in ‘n ekosisteem,
baie interessant, siende dat tussen-takson surrogate soms gesien word as sterker as surrogate gebaseer op omgewingsdata. Verder, taksa het funksioneel gereageer teenoor die klippe in die
landskap. Hierdie tesis ondersteun dus die idee dat omgewingssurrogate wel nuttig is vir
biodiversiteit-bewaring beplanning. Ekosisteme mag vele potensiele elemente van bewarings
belang bevat, maar om sulke elemente as ‘n stel mesofilters te klassifiseer, is ‘n nuttige
manier om spesifieke elemente te gebruik in natuurbewarings evaluasie initiatiewe. Gevolglik
word die konsep van die mesofilter as ‘n praktiese biodiversiteit-bewaring gereedskapstuk
hier bevestig. Ek beredeneer ook die belangrikheid van habitat heterogeniteit vir
biodiversiteit-bewaring van hierdie berggrasveld landskap. Die potensiaal vir optimalisering
van ontwerp en bestuur van landskap konfigurasies, soos ekologiese netwerke, word
beklemtoon. Ons kan met veiligheid nog ‘n gereedskapstuk plaas in die biodiversiteitbewarings
gereedskapkis van hierdie Afrikaberg grasveld ekosisteem.
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