twinspan classification
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2021 ◽  
Vol 42 ◽  
pp. e68062
Author(s):  
Pauline Delbosc ◽  
Mathieu Le Dez ◽  
Jean-Bernard Bouzillé ◽  
Kevin Cianfaglione ◽  
Frédéric Bioret

Carici-Genistetea lobelii Klein 1972 corresponds to cyrno-sardinian oromediterranean cushion scrub and related grasslands. In France, this class is only present in Corsica and the syntaxonomic scheme is debated among phytosociologists. The aim of this paper is to highlight the main plant associations of Carici-Genistetea lobelii Klein 1972 and to define the diagnostic species for each phytosociological unit. We compiled 519 vegetation plots and we applied EuropeanVegetationChecklist expert system for the classes of European vegetation to retain only vegetation plots belonging to Carici-Genistetea lobelii. We obtained a dataset with 189 vegetation plots and we classified them with Modified TWINSPAN classification. Our analyses recognized 6 plant associations and 3 sub-associations already described in the literature; and to describe a new alliance corresponding to the supra-mediterranean vegetations (Genistion salzmannii), a new association (Brimeuro fastigiatae-Juniperetum nanae) and its sub-association (alnetosum suaveolentis). For each of them, we identified diagnostic, constant and dominant species and produced their distribution map. Formal definitions were then written for each phytosociological unit (from subassociation to class) and grouped in an expert system to automatically classify the vegetations of Carici-Genistetea lobelii.


2021 ◽  
Vol 13 (11) ◽  
pp. 6377
Author(s):  
Yasser A. El-Amier ◽  
Ahmed El-Zeiny ◽  
El-Sayed F. El-Halawany ◽  
Ashraf Elsayed ◽  
Mohamed A. El-Esawi ◽  
...  

Spatiotemporal environmental changes lead to disturbances in wild plant habitats, particularly in regions characterized by changeable land use and cover. The present study aims to characterize wild plant habitats in the River Nile region of Dakahlia Governorate using a multidisciplinary approach, incorporating remote sensing, GIS and sampling analyses. Twenty-four stands representing the wild plant habitats in the River Nile region were geographically identified, sampled and analyzed. Water and soil samples were investigated for physical and chemical characteristics. Two calibrated multispectral Landsat images dated 1999 and 2019 were processed to produce LULC, NDSI, NDMI and NDSI to characterize wild plan habitats. The floristic composition showed the presence of 64 species belonging to 53 genera and 28 families. Ecologically, the recorded plant species in the present work can be classified into four main categories, which are separated into three communities according to the TWINSPAN classification. Results showed that the annual loss of agricultural lands (3.98 km2) is closely relevant to the annual expansion of urban areas (4.24 km2). Although the uncontrolled urban sprawl caused loss of agricultural lands, it leads to the expansion of wild plant habitats, represented mainly by the sparse class and partially by the moderately dense class as obtained from NDVI. The increase in mean values of the moisture (NDMI) from 0.034 in 1999 to 0.64 in 2019 may have arisen from the increase in total areas of wild plant habitats during the investigated period (1999–2019). This might increase the suitability of conditions for wild habitats which induces the proliferation of natural plants.


2018 ◽  
Vol 44 (2) ◽  
pp. 267-276 ◽  
Author(s):  
Faizul Haq ◽  
Habib Ahmad ◽  
Zafar Iqbal

Present study was conducted in the mixed Pinus roxburghii Surgent and Pinus wallichiana A.B. Jackson forests of Nandiar Khuwar catchment Battagram District of Pakistan. The aim of this study was to examine the spatial pattern of vegetation composition and its relationship to microclimatic and edaphic factors. Vegetation sampling was carried out using 12 stands between elevations of 1250 - 2050 m in the study area. Four plant communities were recognized through TWINSPAN classification. Life form was dominated by nanophanerophytes and leaf size spectra were dominated by microphyll. The maximum similarity index value (32.9) was recorded between P. roxburghii, P. wallichiana, Q. incana community and Q. incana, P. roxburghii, P. wallichiana community. In Bray-Curtis ordination, maximum ordination score (0.746) was recorded for axis 1. In DCA ordination, maximum gradient length (2.43) was recorded for axis 1 with eigenvalue 0.35. In CCA ordination, maximum eigenvalue was recorded for axis 1 (0.35). The total variance (inertia) in the species data was 2.15, explanatory variables account for 100%. On axis 1 the maximum correlation (−0.749) and maximum tau value (−0.565) was recorded for wet bulb. On axis 2 the maximum negative correlation value was recorded for temperature (−0.553) and maximum tau value was recorded for slope aspect (−0.480).


Hacquetia ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 85-109
Author(s):  
Yakiv Didukh ◽  
Olga Chusova ◽  
Olga Demina

Abstract The order Thymo cretacei-Hyssopetalia cretacei Didukh 1989 combines chalk outcrop plant communities of the southwestern Central Russian Upland. Its specificity can be attributed to a rather peculiar and heterogeneous flora with a large number of endemic species. The question about its origin has caused a lively discussion, which has been going on since the late nineteenth century. Since 1989 works on the classification of these communities have frequently been carried out, but until today no unanimous decision could be reached. The purpose of our research was to conduct a critical analysis of the syntaxonomical structure of Cretaceous outcrop vegetation and to show its difference from the steppe vegetation of the class Festuco-Brometea Br.-Bl. et Tx. ex Soó 1947. The territory of our research covers the southwestern foothills of the Central Russian Upland and the Donetsk Range, located only within the steppe zone and characterised by Cenomanian chalk outcrops. In total 354 relevés were used for the analysis. The modified TWINSPAN classification was used for the analysis. Our research has shown that the order Thymo cretacei-Hyssopetalia cretacei includes twelve associations belonging to three alliances: Artemisio hololeucae-Hyssopion cretacei Romashchenko et al. 1996, Euphorbio cretophilae-Thymion cretacei Didukh 1989 and Centaureo carbonatae-Koelerion talievii Romashchenko et al. 1996.


2018 ◽  
Vol 38 (9) ◽  
Author(s):  
杨国栋 YANG Guodong ◽  
钱慧蓉 QIAN Huirong ◽  
陈林 CHEN Lin ◽  
王贤荣 WANG Xianrong

Bothalia ◽  
2017 ◽  
Vol 47 (2) ◽  
Author(s):  
Mamokete N.V. Dingaan ◽  
Pieter J. Du Preez

Background: Urban vegetation studies have, until recently, been relatively uncommon in South Africa. Yet, natural urban vegetation is constantly competing with and greatly impacted by urbanisation. This vegetation requires proper management and needs to be conserved because it is an important ecological infrastructure.Objectives: The objectives of the study were to identify the main vegetation types within the urban open spaces in the Bloemfontein metropolitan area, and to determine the floristic composition and species diversity of the area.Methods: A total of 248 relevés were classified using the TWINSPAN classification algorithm, and relationships between the communities and the environment were determined with the Detrended Correspondence Analysis and Canonical Correspondence Analysis computer programs. Species diversity was partitioned into α-, β- and γ-diversities.Results: Within the study area, 77 plant families and 248 genera, with a total of 376 plant species, were identified. The largest families are Poaceae, Asteraceae and Fabaceae, whereas the largest genera are Eragrostis, Aristida, Cyperus, Asparagus and Senecio. The study area has high species richness and the most species-rich sites are found adjacent to rivers and streams, and also on the slopes of hills and ridges. The vegetation is classified under five major vegetation types and four sub-units, which show a distinct association with topography and soil texture.Conclusion: The urban vegetation of Bloemfontein is species-rich and should be properly managed and conserved. In particular, the wetlands and rocky outcrops on hills and ridges, which are the most threatened habitats in the study area, need special management.


Hacquetia ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 79-104 ◽  
Author(s):  
Vitaliy Коlomiychuk ◽  
Denys Vynokurov

Abstract Syntaxonomy of the class Festuco-Brometea in Ukraine has barely been still explored. There are some scattered and local data, mainly within the Forest-Steppe zone, which need to be compiled and critically reviewed. Similarly, the Azov Sea coastal zone, which, despite the considerable diversity of habitats, remains unstudied phytosociologically. We have carried out large-scale comparisons of relevés from the Sea of Azov coastline with data from other regions of Ukraine, Europe, and Russia. In total, 2336 relevés were used for the analysis. For the analysis, Modified TWINSPAN classification was used. Diagnostic species were determined by means of the phi fidelity index. In total, 9 associations and 4 subassociations, belonging to four alliances, were identified and categorised as follows: Artemisio-Kochion prostratae (ruderalized steppes), Artemisio tauricae- Festucion valesiacae (saline steppe vegetation on sites affected by the sea or saline ground water), Stipo lessingianae-Salvion nutantis (forb-bunchgrass steppe vegetation) and Tanaceto millefolii-Galatellion villosae (bunchgrass steppes). The last alliance is proposed as a new one.


Koedoe ◽  
2013 ◽  
Vol 55 (1) ◽  
Author(s):  
Mamokete N.V. Dingaan ◽  
Pieter J. Du Preez

Natural vegetation in urban environments is greatly impacted by human activities and it is in constant threat of degradation and destruction as a result of urbanisation. This vegetation, although fragmented, serves an important ecological function and needs to be properly managed and conserved. Studies on urban vegetation are lacking in South Africa, with only a handful having been carried out since the end of the last century. This study was initiated to identify, classify and describe the grassland communities of the urban open spaces in Bloemfontein. Relevés were compiled in 61 sample plots, where species present and habitat information were recorded. Care was taken to restrict sample plots to vegetation in pristine condition, wherever possible, and severely degraded stands were avoided. A two-way indicator species analysis (TWINSPAN) classification, refined by Braun-Blanquet procedures, revealed two distinct major communities, seven communities and four sub-communities. Both detrended and canonical correspondence analyses indicated the vegetation units to be associated with soil texture and pH, although biotic factors such as overgrazing, burning and mowing also influence the composition of the vegetation. The proper management and conservation of urban open spaces requires in-depth knowledge of the spatial distribution, floristic, structural and functional compositions within the major vegetation types in this environment. The present study further contributed towards formulating ways for the proper management, utilisation and functioning of the open spaces within the Bloemfontein area.Conservation implications: The Grassland Biome of South Africa is poorly conserved, mainly because of its status as an agricultural hub of the country. The preservation of natural and semi-natural forms of urban vegetation is important because such vegetation, although often disturbed and degraded, could form dispersal corridors between peri-urban and rural vegetation.


Koedoe ◽  
2011 ◽  
Vol 53 (1) ◽  
Author(s):  
Robert F. Brand ◽  
Leslie R. Brown ◽  
Pieter J. Du Preez

Platberg is an inselberg that presents a refuge for indigenous plants and animals. Uncontrolled human access to this area threatens this sensitive ecosystem. The vegetation of Platberg was investigated to obtain an inventory of the different plant species and communities present in this area. A hierarchical classification, a description and an ecological interpretation of the grassland communities of Platberg are presented. A total of 169 sample plots were placed on a stratified random basis within the study area. From a TWINSPAN classification a total of 27 different plant communities, which can be grouped into two major community types, nine communities, 18 sub-communities and six variants, were identified. A significant difference in species richness was found between the two major communities, with the higher-altitude communities having a higher species richness than the communities on the lower-lying slopes. A total of 26 endemic or near endemic Drakensberg Alpine Centre species were recorded. Conservation implications: Anthropogenic influences are felt globally on ecosystems. High-altitude habitats and organisms will be affected first. Inselbergs have high levels of endemic organisms and are reservoirs and refugia for unique genetic material. This grassland plant community survey of Platberg provides valuable information on inselberg ecology for conservation planning.


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