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Rule-based land cover classification model : expert system integration of image and non-image spatial dataKidane, Dawit K. 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Remote sensing and image processing tools provide speedy and up-to-date information on land
resources. Although remote sensing is the most effective means of land cover and land use mapping, it
is not without limitations. The accuracy of image analysis depends on a number of factors, of which the
image classifier used is probably the most significant. It is noted that there is no perfect classifier, but
some robust classifiers achieve higher accuracy results than others. For certain land cover/uses,
discrimination based only on spectral properties is extremely difficult and often produces poor results.
The use of ancillary data can improve the classification process. Some classifiers incorporate ancillary
data before or after the classification process, which limits the full utilization of the information
contained in the ancillary data. Expert classification, on the other hand, makes better use of ancillary
data by incorporating data directly into the classification process.
In this study an expert classification model was developed based on spatial operations designed to
identify a specific land cover/use, by integrating both spectral and available ancillary data. Ancillary
data were derived either from the spectral channels or from other spatial data sources such as DEM
(Digital Elevation Model) and topographical maps. The model was developed in ERDAS Imagine
image-processing software, using the expert engineer as a final integrator of the different constituent
spatial operations. An attempt was made to identify the Level I land cover classes in the South African
National Land Cover classification scheme hierarchy. Rules were determined on the basis of expert
knowledge or statistical calculations of mean and variance on training samples. Although rules could
be determined by using statistical applications, such as the classification analysis regression tree
(CART), the absence of adequate and accurate training data for all land cover classes and the fact that
all land cover classes do not require the same predictor variables makes this option less desirable. The
result of the accuracy assessment showed that the overall classification accuracy was 84.3% and kappa
statistics 0.829. Although this level of accuracy might be suitable for most applications, the model is
flexible enough to be improved further. / AFRIKAANSE OPSOMMING: Afstandswaameming-en beeldverwerkingstegnieke kan akkurate informasie oorbodemhulpbronne
weergee. Alhoewel afstandswaameming die mees effektiewe manier van grondbedekking en
grondgebruikkartering is, is dit nie sonder beperkinge nie. Die akkuraatheid van beeldverwerking is
afhanklik van verskeie faktore, waarvan die beeld klassifiseerder wat gebruik word, waarskynlik die
belangrikste faktor is. Dit is welbekend dat daar geen perfekte klassifiseerder is nie, alhoewel sekere
kragtige klassifiseerders hoër akkuraatheid as ander behaal. Vir sekere grondbedekking en -gebruike is
uitkenning gebaseer op spektrale eienskappe uiters moeilik en dikwels word swak resultate behaal. Die
gebruik van aanvullende data, kan die klassifikasieproses verbeter. Sommige klassifiseerders
inkorporeer aanvullende data voor of na die klassifikasieproses, wat die volle aanwending van die
informasie in die aanvullende data beperk. Deskundige klassifikasie, aan die ander kant, maak beter
gebruik van aanvullende data deurdat dit data direk in die klassifikasieproses inkorporeer.
Tydens hierdie studie is 'n deskundige klassifikasiemodel ontwikkel gebaseer op ruimtelike
verwerkings, wat ontwerp is om spesifieke grondbedekking en -gebruike te identifiseer. Laasgenoemde
is behaal deur beide spektrale en beskikbare aanvullende data te integreer. Aanvullende data is afgelei
van, óf spektrale eienskappe, óf ander ruimtelike bronne soos 'n DEM (Digitale Elevasie Model) en
topografiese kaarte. Die model is ontwikkel in ERDAS Imagine beeldverwerking sagteware, waar die
'expert engineer' as finale integreerder van die verskillende samestellende ruimtelike verwerkings
gebruik is. 'n Poging is aangewend om die Klas I grondbedekkingklasse, in die Suid-Afrikaanse
Nasionale Grondbedekking klassifikasiesisteem te identifiseer. Reëls is vasgestel aan die hand van
deskundige begrippe of eenvoudige statistiese berekeninge van die gemiddelde en variansie van
opleidingsdata. Alhoewel reëls met behulp van statistiese toepassings, soos die 'classification analysis
regression tree (CART)' vasgestel kon word, maak die afwesigheid van genoegsame en akkurate
opleidingsdata vir al die grondbedekkingsklasse hierdie opsie minder aantreklik. Bykomend tot
laasgenoemde, vereis alle grondbedekkingsklasse nie dieselfde voorspellingsveranderlikes nie. Die
resultaat van hierdie akkuraatheidsskatting toon dat die algehele klassifikasie-akkuraatheid 84.3% was
en die kappa statistieke 0.829. Alhoewel hierdie vlak van akkuraatheid vir die meeste toepassings
geskik is, is die model aanpasbaar genoeg om verder te verbeter.
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Archaeological Application of Airborne LiDAR with Object-Based Vegetation Classification and Visualization Techniques at the Lowland Maya Site of Ceibal, GuatemalaInomata, Takeshi, Pinzón, Flory, Ranchos, José Luis, Haraguchi, Tsuyoshi, Nasu, Hiroo, Fernandez-Diaz, Juan Carlos, Aoyama, Kazuo, Yonenobu, Hitoshi 05 June 2017 (has links)
The successful analysis of LiDAR data for archaeological research requires an evaluation of effects of different vegetation types and the use of adequate visualization techniques for the identification of archaeological features. The Ceibal-Petexbatun Archaeological Project conducted a LiDAR survey of an area of 20 x 20 km around the Maya site of Ceibal, Guatemala, which comprises diverse vegetation classes, including rainforest, secondary vegetation, agricultural fields, and pastures. We developed a classification of vegetation through object-based image analysis (OBIA), primarily using LiDAR-derived datasets, and evaluated various visualization techniques of LiDAR data. We then compared probable archaeological features identified in the LiDAR data with the archaeological map produced by Harvard University in the 1960s and conducted ground-truthing in sample areas. This study demonstrates the effectiveness of the OBIA approach to vegetation classification in archaeological applications, and suggests that the Red Relief Image Map (RRIM) aids the efficient identification of subtle archaeological features. LiDAR functioned reasonably well for the thick rainforest in this high precipitation region, but the densest parts of foliage appear to create patches with no or few ground points, which make the identification of small structures problematic.
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Terrestrial Ecosystem Classification in the Rocky Mountains, Northern UtahKusbach, Antonin 01 May 2010 (has links)
Currently, there is no comprehensive terrestrial ecosystem classification for the central Rocky Mountains of the United States. A comprehensive classification of terrestrial ecosystems in a mountainous study area in northern Utah was developed incorporating direct gradient analysis, spatial hierarchy theory, the zonal concept, and concepts of diagnostic species and fidelity, together with the biogeoclimatic ecosystem classification approach used in British Columbia, Canada. This classification was derived from vegetation and environmental sampling of both forest and non-forest ecosystems. The SNOwpack TELemetry (SNOTEL) and The National Weather Service (NWS) Cooperative Observer Program (COOP) weather station network were used to approximate climate of 163 sample plots.
Within the large environmental diversity of the study area, three levels of ecosystem organization were distinguished: (1) macroclimatic - regional climate; (2) mesoclimatic, accounting for local climate and moisture distribution; and (3) edaphic - soil fertility. These three levels represent, in order, the L+1, L, and L-1 levels in a spatial hierarchy.
Based on vegetation physiognomy, climatic data, and taxonomic classification of zonal soils, two vegetation geo-climatic zones were identified at the macroclimatic (L+1) level: (1) montane zone with Rocky Mountain juniper and Douglas-fir; and (2) subalpine zone with Engelmann spruce and subalpine fir as climatic climax species.
A vegetation classification was developed by combining vegetation samples (relevés) into meaningful vegetation units.
A site classification was developed, based on dominant environmental gradients within the subalpine vegetation geo-climatic zone. Site classes were specified and a site grid was constructed. This site classification was coupled with the vegetation classification. Each plant community was associated with its environmental space within the site grid. This vegetation-site overlay allowed ecosystems to be differentiated environmentally and a structure, combining zonal, vegetation, and site classifications, forms a comprehensive ecosystem classification.
Based on assessment of plant communities' environmental demands and site vegetation potential, the comprehensive classification system enables inferences about site history and successional status of ecosystems. This classification is consistent with the recent USDA, Forest Service ECOMAP and Terrestrial Ecological Unit Inventory structure and may serve as a valuable tool not only in vegetation, climatic, or soil studies but also in practical ecosystem management.
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A vegetation classification and management plan for the Hondekraal section of the Loskopdam Nature ReserveFilmalter, Nicolene 12 1900 (has links)
As part of a vegetation survey program for the newly acquired farms incorporated into the Loskop Dam Nature Reserve, the vegetation of the Hondekraal Section was investigated. The study provides an ecological basis for establishing an efficient wildlife management plan for the Reserve. From a TWINSPAN classification, refined by Braun-Blanquet procedures, 12 plant communities, which can be grouped into eight major plant communities, were identified. A classification and description of the major plant communities are presented as well as a management plan. Descriptions of the plant communities include characteristic species as well as prominent and less conspicuous species of the tree, shrub, herb and grass strata. This study proves that the extended land incorporated into the Reserve contributes to the biological diversity of the Reserve. / Environmental Sciences / M. Tech. (Nature Conservation)
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Exploring patterns of phytodiversity, ethnobotany, plant geography and vegetation in the mountains of Miandam, Swat, Northern PakistanAkhtar, Naveed 21 August 2014 (has links)
Das Miandam-Untersuchungsgebiet (35° 1′- 5′ N, 72° 30′-37′ E) liegt in der Swat-Region der Provinz Khyber Pakhtunkhwa (ehemals North West Frontier Province) im nördlichen Pakistan. Die vorliegende Arbeit berücksichtigt sowohl ethnobotanische und pflanzensoziologische Aspekte als auch die Pflanzenartendiversität innerhalb des Gebietes.
Aufgrund der hohen Habitatvielfalt weist das Miandam-Gebiet einen großen Reichtum von Medizinalpflanzen auf. Die im Rahmen der Arbeit durchgeführte ethnobotanische Studie dokumentiert das Vorkommen der Medizinalpflanzen sowie deren Nutzung in der Region. Weiterhin wurden die durch Sammlerpräferierten Lebensräume bestimmt und evaluiert inwiefern die Heilpflanzen durch Sammlung und Habitatzerstörung bedroht werden. Insgesamt wurden 106 traditionelle Heilpflanzen aus 54 Pflanzenfamilien verzeichnet. Zu den am häufigsten gefundenen Wuchsformen zählten mehrjährige (43%) und kurzlebige Kräuter (23%), Sträucher (16%) und Bäume (15%). Ein Großteil der untersuchten Heilpflanzen und ihrer Produkte wird zur Behandlung von Magen-Darm-Erkrankungen eingesetzt. Die Produkte werden vorrangig als Sud oder Pulver zubereitet und oral angewendet. Achtzig der 106 traditionellen Heilpflanzen gehören der Gruppe der einheimischen Arten an. Fast 50% der Pflanzenarten treten dabei in synanthroper Vegetation auf, während der Rest in naturnaher Umgebung (z.B. extensiv beweidete Wald- und Graslandbereiche) vorgefunden werden kann. Wälder sind der Ursprung der meisten nicht synanthropen einheimischen Medizinalpflanzen. Drei Arten (Aconitum violaceum, Colchicum luteum, Jasminum humile) können als Folge intensiven Sammelns als bedroht eingestuft werden.
Um die pflanzensoziologischen und phytogeografischen Aspekte des Projektes abzudecken wurde die Vegetation des Miandam-Gebietes mit einem Fokus auf Wäldern, Gebüschen und anderen Formationen untersucht. Die Ergebnisse der Vegetationserhebungen wurden mit denen anderer Studien in der weiteren Umgebung des Hindukush-Himalayas verglichen. Weiterhin wurde untersucht inwiefern die Waldökosysteme durch anthropogene Aktivitäten im Untersuchungsgebiet bedroht sind. Die im Gebiet verzeichneten Gefäßpflanzenarten umfassen insgesamt 33 Bäume, 52 Sträucher, 305 Kräuter und 11 Lianen. Basierend auf einer multivariaten Analyse konnten 12 Pflanzengesellschaften identifiziert werden. Die Spanne dieser Gesellschaften reichte von subtropischen semiariden Wäldern mit Ailanthus altissima im Tiefland zu alpinen Rasen von Sibbaldia cuneata durchsetzt mit Juniperus. Die dominierende Vegetation des Untersuchungsgebietes besteht aus von Abies pindrow und Viburnum grandiflorum Wäldern. Eine georeferenzierte Karte der Vegetation erleichtert die Lokalisierung der ökologisch interessanten Vegetation.
Artenreichtum und –diversität wurden entlang eines Höhengradienten untersucht. Dazu wurde die Alpha- sowie Beta-Diversität verschiedener Wuchsformtypen bestimmt. Der Artenreichtum aller Gefäßpflanzenarten erreichte sein Maximum zwischen 2200-2500 m. Dagegen zeigte der Artenreichtum der Sträucher einen glockenkurvenartigen Verlauf mit einem Maximum zwischen 2000 und 2200 m. Die höchste Alpha-Diversität der Gefäßpflanzenarten wurde in den tieferen Lagen des Untersuchungsgebietes verzeichnet. Die Beta-Diversität aller Wuchsformtypen zeigte entlang des gesamten Höhengradienten hohe Werte und somit einen starken Artenwechsel. Die Beta-Diversität der Straucharten fluktuiert entlang des Höhengradienten und zeigt damit ein einzigartiges Muster.
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Vegetation change over fifty years in humid grasslands of KwaZulu-Natal (Acocks's sites)Marriott, David John. 23 December 2013 (has links)
Eighty three of Acocks's sites, originally surveyed about 50
years ago, were resurveyed in 1996 to determine the extent of
grassland change in the humid grasslands of KwaZulu-Natal. Sites
were relocated using 1:10 000 scale ortho-photos and present land
cover was determined for each site. Forty six of the sites that
were still under original grassland were further examined to
determine present species composition. A survey method was
designed that would emulate Acocks's data and comparisons were
drawn between original and present species composition. These
differences were then analysed together with some environmental
variables to try to determine the factors which had the most
influence on the change and which environment and management
factors are related to the present variation in composition among
sites.
Of the 83 sites, 26 had changed from natural vegetation to some
other form of agriculture such as forestry or cultivation. Most
of this change had occurred in the Natal Mistbelt Ngongoni Veld
where large areas are forested. Cultivation is found
predominantly in the communal areas where subsistence, cultivation
practices are employed.
The remainder of the sites had changed significantly in terms of
their species composition. The most pronounced change had
occurred in areas under communal tenure although significant
changes had occurred in the commercially farmed areas. The
direction of change was also more consistent towards species that
commonly predominate in heavily grazed areas in the communal
areas compared to the commercial areas. The exact reasons for
this were unclear but this could possibly be attributed to
heavier stocking rates in the communal areas.
Change in floristic composition was also more pronounced at lower
altitudes where the mean annual rainfall is lower and the mean
annual temperature higher. This could possibly be a result of the vegetation at lower altitudes being less stable and thus less
resistant to change.
Basal cover differed significantly between commercial and
communally grazed sites. Lower basal cover was found in the
communal sites where intensive grazing limits the growth of
individual tufts. Number of species found at each site did not
differ significantly between communal and commercially grazed
sites.
This study was also a practical implementation of the resurveying
of Acocks's sites and the original data set was found to be a
useful baseline data set to determine coarse long-term changes
in the vegetation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.
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A vegetation classification and management plan for the Hondekraal section of the Loskopdam Nature ReserveFilmalter, Nicolene 12 1900 (has links)
As part of a vegetation survey program for the newly acquired farms incorporated into the Loskop Dam Nature Reserve, the vegetation of the Hondekraal Section was investigated. The study provides an ecological basis for establishing an efficient wildlife management plan for the Reserve. From a TWINSPAN classification, refined by Braun-Blanquet procedures, 12 plant communities, which can be grouped into eight major plant communities, were identified. A classification and description of the major plant communities are presented as well as a management plan. Descriptions of the plant communities include characteristic species as well as prominent and less conspicuous species of the tree, shrub, herb and grass strata. This study proves that the extended land incorporated into the Reserve contributes to the biological diversity of the Reserve. / Environmental Sciences / M. Tech. (Nature Conservation)
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Etudes écologique, floristique, phytosociologique et ethnobotanique de la forêt marécageuse de Lokoli (Zogbodomey – Bénin): Ecological, floristic, phytosociological and ethnobotanical studies of the swamp forest of Lokoli (Zogbodomey - Benin)Dan, Bai 29 June 2009 (has links)
La forêt marécageuse de Lokoli, située dans le sud du Bénin est une formation non protégée, bien qu’elle soit la seule forêt marécageuse avec un cours d’eau permanent connue en Afrique de l’Ouest. Pour envisager une prise de décision de conservation et de protection de cet écosystème forestier, il est important de disposer d’une meilleure connaissance de sa flore, de sa végétation et de son fonctionnement. C’est dans ce cadre que la présente étude a été envisagée. Les données collectées concernent le milieu naturel, la structure de la forêt, la régénération naturelle des espèces et les usages faits des Produits Forestiers Non Ligneux (PFNL). Le milieu naturel se compose d’un substratum acide (pH variant de 3,5 à 5,5) et argilo-sableux. Le cortège floristique de cette forêt est composé de 241 espèces réparties en 185 genres et 70 familles dont des espèces endémiques (Uapaca paludosa) ou en danger (Hallea ledermannii), Nauclea xanthoxylon, etc. Sept groupements végétaux ont été identifiés (forêt primaire inondée à Alstonia congensis et Xylopia rubescens, forêt secondaire inondée à Ficus trichopoda et Spondianthus preussii et raphiale à Raphia hookeri et Anthocleista vogelii en forêt ;forêt ripicole à Alchornea cordifolia et Mitragyna inermis, savane marécageuse à Ficus asperifolia et Paullinia pinnata ;prairie marécageuse à Cyclosorus gongylodes et Polygonum pulchrum et enfin prairie marécageuse à Rhynchospora corymbosa et Ludwigia abyssinica en lisière) avec des précisions sur leurs caractéristiques floristiques, biologiques, phytogéographiques et écosociologiques. Les mésophanérophytes sont abondants en forêt alors qu’en lisière, ce sont les microphanérophytes qui sont les plus nombreux. Ces groupements constituent un refuge pour de nombreuses espèces animales dont Barboides britzi, poisson déterminé pour la première fois en 2006. D’après cette étude, on note une bonne régénération des espèces forestières malgré une recrudescence des trouées liées à l’installation de champs de Colocasia esculenta. Parmi les 75 espèces, source de PFNL recensées, les produits et sous-produits issus de Raphia hookeri sont les plus exploités car ils constituent pour les populations riveraines d’importantes sources de revenus. Ces PFNL sont exploités à Lokoli pour plusieurs usages à savoir l’alimentation, l’emballage, boisson alcoolisée, recettes médicinales, construction, etc. Le nombre de pieds de Raphia hookeri saignés par an est de 15.452 par 320 exploitants dont 148 cueilleurs, 81 transformateurs et 91 commerçants ;ce qui fournit aux exploitants des revenus de l’ordre de 28.000 à 159.000 FCFA (42,7 à 242,4 euros) par mois et par exploitant, sans oublier les autres activités menées par les riverains dans cet écosystème. On note une forte pression anthropique sur cette formation qu’il est donc urgent de protéger. En effet, elle dispose d’importants atouts qui militent en faveur de sa conservation. Elle abrite des espèces végétales et animales rares, endémiques, vulnérables et en danger (inscrites sur la liste rouge de l’UICN), telles que :Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. La forêt marécageuse de Lokoli joue un rôle de refuge pour toutes ces espèces qui y trouvent leur niche écologique. Sur le plan socio-économique, la FML fournit aux populations riveraines des revenus pour leur subsistance. Toutes ces potentialités font d’elle une Forêt à Haute Valeur pour la Conservation (FHVC) et elle pourrait constituer une véritable réserve de biosphère dans le Sud-Bénin. / The swamp forest of Lokoli, located in the south of Benin, is a non-protected area, although it is the only swamp forest in West Africa accompanied by a river which always contains water. To be able to make decisions concerning the conservation and protection of this forest ecosystem, it is important to have a better knowledge of its flora, its vegetation and its ecology and dynamics. It is within this framework that the present study was considered. The data that were collected relate to the natural environment, the structure of the forest, the natural regeneration of the species and the uses of the Non Timber Forest Products (NTFP). The natural environment is composed of a substratum which is acid (pH varying from 3.5 to 5.5) and loamy-sandy. The floristic composition of this forest is composed of 241 plant species from 185 genera and 70 families. Seven vegetation types were identified: 1. Inundated primary forest with Alstonia congensis and Xylopia rubescens; 2. Inundated secondary forest with Ficus trichopoda and Spondianthus preussii; 3. Raphia forest with Raphia hookeri and Anthocleista vogelii; 4. Riparian forest with Alchornea cordifolia and Mitragyna inermis; 5. Marshy savanna with Ficus asperifolia and Paullinia pinnata; 6. Marshy savanna with Cyclosorus gongylodes and Polygonum pulchrum; and 7. Marshy savanna with Rhynchospora corymbosa and Ludwigia abyssinica. Precise details are given on their floristic, biological, phytogeographical and phytosociological characteristics. The mesophanerophytes are abundant in forest whereas at forest edges the microphanerophytes are most numerous. These vegetation types constitute a refuge for many animal species, for example Barboides britzi, a species of fish first identified in 2006. This study noted a good regeneration of forest species, in spite of disturbance related to the installation of fields of Colocasia esculenta. About 75 investigated NTFP are exploited in Lokoli for many purposes, among which food, packaging, alcoholic drinks, medicines, construction, etc. Among the listed NTFP, the products and by-products made from Raphia hookeri are the most important because they are important sources of revenue for the inhabitants of the area. The number of stems of Raphia used per year for palm wine production is 15.452 by the 320 inhabitants, including 148 gatherers, 81 transformers and 91 tradesmen. This provides to the inhabitants an income of about 28,000 to 159,000 FCFA per month and per inhabitant, without forgetting the other activities undertaken by these inhabitants. This results in a strong human pressure on the vegetation of the area which is therefore in urgent need of protection. The vegetation of the Lokoli forest has important values which indicate its conservation concern. It shelters plant and animal species that are endemic and/or endangered or vulnerable according to the red list of the IUCN, such as: Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. The swamp forest of Lokoli is a refuge for all these species who find here their ecological niche. On the socio-economic level, the Lokoli forest provides to the inhabitants an income for their subsistence. The Lokoli forest in southern Benin is a forest with a high conservation value and it has the potential to become a “biosphere reserve”. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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Vegetational and landscape level responses to water level fluctuations in Finnish, mid-boreal aapa mire – aro wetland environmentsLaitinen, J. (Jarmo) 09 September 2008 (has links)
Abstract
Gradient, which is largely considered to be related to water level in mires, is referred to as a microtopographic mud bottom to carpet to lawn to hummock level gradient or the hummock level to intermediate level (lawn) to flark level gradient. The relationship of this vegetation gradient to various physical water level characteristics was studied.
The general classification used in the present summary paper divides the aro vegetation of the inland of Northern Ostrobothnia into two main groups: (a) treeless fen aro vegetation (Juncus supinus, Carex lasiocarpa, Rhynchospora fusca, Molinia caerulea) and (b) heath aro vegetation (Polytrichum commune). The first group (a) was divided into fen aro wetlands with an approximately10 cm peaty layer at most and into aro fens with a peat layer thicker than 10 cm.
The treatment of the water level gradient was divided into three main groups. (1) The mean water level correlated with mire surface levels (microtopographic gradient) within mires with slight water level fluctuations and partly within mires with considerable water level fluctuations. (2) Three habitat groups could be distinguished on the basis of the range of water level fluctuation i.e. mires with slight water level fluctuations, mires with considerable water level fluctuations and the aro vegetation with extreme water level fluctuations. (3) The timing of water level fluctuations indicated that there are different types of patterns within aro wetlands, the seasonal pattern being mainly a response to yearly snow melt and the several-year-fluctuation pattern being related to the regional groundwater table fluctuation in mineral soils (heath forests). A link was suggested between the stability of the water regime and peat production in local aapa mire – aro wetland environments. From the point of view of peatland plants the direction of variation from a stable to an unstable water regime in aapa mire – aro wetland environments represents a transition towards more and more harsh ecological conditions, partly forming a gradient through natural disturbance.
A qualitative functional model was provided for the mire – aro wetland systems of Northern Ostrobothnia. The model supposes differences in the characteristics of peat between two functional complexes within a mire system. Finally, the model for local mire – aro wetland systems was converted to a general from: diplotelmic (acrotelm) mires were divided into two subtypes (diplotelmic water stabilization mires, diplotelmic water fluctuation mires) and the relationship of those subtypes to percolation mires and seasonal wetlands was considered.
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Vegetation ecology of the Soutpansberg and Blouberg area in the Limpopo ProvinceMostert, T.H.C. (Theodorus Hendrik Cornelis) 16 March 2010 (has links)
The fast growing local human population, especially through immigration from countries north of South Africa, is placing the Soutpansberg and Blouberg areas under increasing pressure. The insatiable demand for more arable land within these agriculturally marginal and semi-arid areas is leading to severe degradation of the remaining natural resources. The Soutpansberg–Blouberg region has been recognized as a Centre of Endemism and is regarded as a region of exceptionally high biological diversity. The Soutpansberg Conservancy and the Blouberg Nature Reserve reveal extremely rich diversities of plant communities relative to the sizes of these conservation areas. The Major Vegetation Types and plant communities of the Soutpansberg Centre of Endemism are described in detail with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 466 sample plots were ordinated using a Detrended Correspondence Analysis (DECORANA) and classified using Two–way Indicator Species Analysis(TWINSPAN). The resulting classification was further refined with table–sorting procedures based on the Braun–Blanquet floristic–sociological approach of vegetation classification using MEGATAB. Eight Major Vegetation Types were identified and described as Eragrostis lehmanniana var. lehmanniana–Sclerocarya birrea subsp. caffra BNR Northern Plains Bushveld, Euclea divinorum–Acacia tortilis BNR Southern Plains Bushveld, Englerophytum magalismontanum–Combretum molle BNR Mountain Bushveld, Adansonia digitata–Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis–Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon–Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida–Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora–Rhus chirendensis Soutpansberg Forest Vegetation. Plant communities of each of the Major Vegetation Types are described. The primary ecological drivers of the event-driven and the classic climax vegetation types are discussed and management recommendations are made for effective conservation of these last remaining pockets of wilderness. The available data supports the recognition of the region as an important Centre of Plant Endemism and Biological Diversity requiring conservation attention. Copyright / Thesis (PhD)--University of Pretoria, 2010. / Plant Science / unrestricted
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