Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 21 for “"twinspan"”.
-
The effect of native forest dynamics upon the arrangements of species in oak forests-analysis of heterogeneity effects at the example of epigeal arthropods
… were assessed around each pitfall trap. A TWINSPAN analyses separated pitfall traps from the natural forest from traps of the managed forest. A subsequent discriminant analyses revealed that the temperature, the visible sky, the plant diversity and the mean diameter at breast height as key …
-
A hierarchical phytosociology of the Greater Zandvlei area
… to create a hierarchical phytosociology using TWINSPAN and DCA-ordination analyses. 3 major community types were identified, which were then subdivided to reveal 6 community types important to future management: Moist Grassland/Wetland Disturbed Parkland, Dune Asteraceous Fynbos, Thicket/Shrub …
-
A gradient analysis of Coleogyne communities in Southern Nevada
… from two-way indicator species analysis (TWINSPAN) in the Spring and Sheep Mountain Ranges. Precipitation and soil moisture were positively correlated with elevation; air and soil temperatures were negatively correlated with elevation; Coleogyne density was positively correlated with soil …
-
A comparison of floristic diversity in old-growth versus mid-successional secondary-growth hardwood forests of the White Mountain National Forest, New Hampshire, United States
… National Forest (WMNF). Cluster analysis and TWINSPAN grouped the secondary sites within two steps. Old-growth floras were significantly richer in total, total herbaceous, woodland herbaceous, and unique herbaceous species. Abundance distributions of the two treatment groups were significantly …
-
Macroinvertebrate composition of the upper Georges River with reference to urban, industrial and agricultural impacts
… (ANOVA), Two Way Indicator Species Analysis (TWINSPAN) and Semi-strong Hybrid MultiDimensional Scaling (MDS), Principal Axis Correlation (PCC) and Monte-Carlo sampling (MCAO) in PATN. The data were fourth root transformed and a Bray-Curtis Dissimilarity Matrix was used in MOS. The reference …
-
Floristic and dynamics of Sand Forest, a subtropical dry forest type in South Africa
… the dynamics of old-growth dry forests. Twinspan classification and DCA ordination (Detrended Correspondence Analysis, an indirect gradient analysis) of a wide range of forest samples in north-eastern KwaZulu Natal, South Africa, indicated that Tropical Dry Forest species composition …
-
Post-management vegetation change in upland heather moorland, with particular reference to the nutrient status of soils : Lake Vyrnwy Estate, Powys, Mid Wales
… Multivariate methods of classification (TWINSPAN) and indirect gradient analysis (DECORANA) were used to reveal pattern in the vegetation data, which might be attributable to the management treatments defining each of the chronosequence stages.<br/><br/>TWINSPAN was successful in …
-
The Influence of Livestock grazing on Plant Species Diversity and Distribution at Kiranjeranje Ward-Kilwa District
… species were classified using a computer program TWINSPAN and detrended correspondence analysis (DCA) in which three major plant communities were identified. Canonical correspondence analysis (CCA) revealed that Grazing intensity(r =-0.9439), silt(r = -0.7282), sand(r=0.7886) and clay(r = -0.7607) …
-
Classification and dynamics of the forest vegetation of Hluhluwe Nature Reserve, Kwa Zulu-Natal
… Data were analysed by the multivariate programs, TWINSPAN and CANOCO. The composition of the canopy and subcanopy is distinct. Four canopy and two subcanopy communities can be detected. Community succession in the mature forest takes the form of almost random replacement of canopy trees through …
-
A biogeographic analysis of the seaweed flora of the west coast of southern Africa, from Lüderitz to Cape Agulhas
… were reviewed across 15 geographic regions. A TWINSPAN analysis showed a clear division of the area into two separate species communities. These two communities are the Benguela province, and the western overlap region between the Benguela and Agulhas provinces. The western overlap region was …
-
Caracterización edáfica de los principales pastizales naturales del valle del Paular (Madrid)
… fisiográficas y con auxilio del programa TWINSPAN. Se ha nutilizado técnicas de clasificación sobre los inventarios florísticos realizados en los punto de muestreo para determinar los tipos de pastos y su coincidencia con la clasificación fitosociológica directa. Para cada tipo de pastizal …
-
Phytosociology and vegetation ecology of uMlalazi Nature Reserve
… Classification was completed using the modified TWINSPAN algorithm, resulting in thirteen plant communities. These communities are described in terms of their structure, composition and distribution. These communities can be divided into those that occur on clay soils and those that occur on …
-
The colonisation by vegetation of colliery spoil heaps in the Forest of Dean, Gloucestershire, and implications for biodiversity management
… complementary multivariate analysis techniques, TWINSPAN and DCA. Mean (S)/quadrat and Shannon 'E' diversity indices were calculated.<br/><br/>Succession was measured using a series of 'expected trends'. Species-richness increased over time until 60 years since disturbance, but the …
-
The vegetation of Paulshoek, Namaqualand : phytosociology and landuse impacts
… and lowlands vegetation. Data was subjected to TWINSPAN analysis, CCA, diversity, similarity and evenness investigations. Furthermore, the data set was subjected to Kruskal Wallis one way ANOVA, multiple comparisons with t distribution test and Mann-Whitney statistical tests to determine …
-
Vegetation patterns along the Middle Fork of the Flathead River, Glacier National Park, Montana
… to inundate each point along the transects. TWINSPAN (Hill 1979) analysis was used to identify four distinct cover types and several key indicator species. Direct gradient analysis was used to array cover types and key indicator species along a hydrologic gradient of inundation duration. …
-
A comparative study of Corynephorus canescens (L.) P.Beauv. communities of inland sand dunes in England and Poland
… multivariate analysis and, for the vegetation, TWINSPAN analysis. 153 taxa of plants and 251 of invertebrates were identified. Though strongly distributed on a regional basis, both flora and invertebrate fauna showed relationships particularly between Polish and West Midlands sites. Analysis of …
-
Ecological patterns, community classification, and a comparison of approaches for predicting biological and habitat reference conditions in New Hampshire streams
… log transformed abundances classified using TWINSPAN produced the best classification as measured using specific criteria. Seven natural biotic community types primarily arranged along the longitudinal stream profile were classified. Geographic classifications based on ecoregions and …
-
Calluna vulgaris regeneration on upland moorland post-wildfire.
… using Two-way species indicator analysis (Twinspan), permanent quadrats were established within representative areas of identified vegetation sub-communities. Twice yearly surveys (spring and autumn) were undertaken within areas defined by these quadrats. Results of vegetation survey showed …
-
Changes in soil invertebrate decomposer communities during regeneration of Scots Pine within the Abernethy Forest Reserve, Scotland
… on invertebrate communities were analysed using TWINSPAN and CANOCO. Results suggested that differences were present in invertebrate abundance and community structure between the two soil types, with more variation occurring along the peat transect than podzol transect. A number of oribatid …
-
An investigation into the ecology and biogeography of subtidal seaweed communities of KwaZulu-Natal
… Analysis] and hierarchical clustering analyses [TWINSPAN]. A remarkable species richness [294 species] was recorded in 71 quadrats [a total sampling area of 4.44 m 2 ], with a maximum of 40 species being recorded in a single quadrat. Crustose corallines and blue-green algae were not included in …
Page 1 of 2