scholarly journals Diversity and degradation of the vegetation of mountain belt forests of central Adjara (the Lesser Caucasus), Georgia

2021 ◽  
Vol 67 (No. 5) ◽  
pp. 219-241
Author(s):  
Nana Goginashvili ◽  
Natalia Togonidze ◽  
Irina Tvauri ◽  
Zurab Manvelidze ◽  
Nino Memiadze ◽  
...  

The Colchis forests contribute to the biodiversity hotspot in the Caucasus eco-region. We investigated the plant diversity of these forests in the central part of Adjara (W Georgia). The aims of our study were (i) to differentiate the forest vegetation diversity in the mountain belt forests by means of phytosociology, (ii) to associate endemic taxa with the revealed forest types, and (iii) to assess degradation of the forest vegetation diversity by means of environmental abiotic and biotic factors. We sampled the forest vegetation on 135 plots with the size of 10 × 10 m2 and 237 plant taxa were recorded. Principal Component Analysis (PCA) was used to reduce environmental variables to a few orthogonal composed variables. The derived factors (PC1, PC2) were used in ordination analysis to group the plot measured forest vegetation diversity. One-way ANOVA was used for the comparison of means between the separated clusters in PCA. Two-Way Indicator Species Analysis (TWINSPAN) and Indicator Species Analysis (ISA) were applied for the association of the plant taxa with the vegetation cluster groups separated by PCA. Our analysis revealed two general ecologically distinct forest types which were characterized as dry and humid forests. Endemic species had the main occurrence in dry forests of the studied territory which are heavily impacted by the local land use. The results indicated that the vegetation diversity of dry forests is under higher threat of degradation than that of humid ones because these forests are not protected and are subjected to non-sustainable forest exploitation. Additionally, many rural and invasive plant species change the native plant assemblages. Based on our findings, we recommend to the organization which manages the local forests to find a balance between the use of forest resources and protection of the unique floristic diversity of local forests in order to avoid their degradation.

2014 ◽  
Vol 1010-1012 ◽  
pp. 121-125
Author(s):  
Wen Bin Li ◽  
Zhi Ming Mo ◽  
Xing Ting Chen ◽  
Chun Huang ◽  
Ming Feng Xu

To examine the impact of habitat heterogeneity on the bird communities, we investigated the structural differences of various bird communities occurring in heterogeneous habitats in the subtropical hilly areas of southern China. We used indicator Species Analysis (ISA) to test the association of specific bird species to particular habitats. We performed Two-way Cluster Analysis to find species patterning in response to habitat fragmentation. Our results demonstrated that heterogeneous habitats promoted bird diversity and human activities affected bird behavior. Indicator Species Analysis demonstrated that similar habitats had similar bird communities, while different habitats supported various bird indicator species. Although habitat diversity increased bird diversity of a region, it was unfavorable for the maintenance of specialized birds in the forests of the subtropical hilly area.


1970 ◽  
Vol 3 ◽  
pp. 23-31 ◽  
Author(s):  
R. K. Manhas ◽  
M. K. Gautam ◽  
Deepa Kumari

In swamp distribution, dominance and survival of a species is very much governed by the soil moisture and period of flooding. The present study was conducted to classify the communities and plant species, and to have an idea about various associations of plants present in the swamp with respect to soil moisture. Two way indicator species analysis (TWINSPAN) classified the communities into four and plant species into eleven groups. The communities with least soil moisture were the first to be segregated and with highest soil moisture last. Similarly, the species growing in drier condition was clustered separately from the moisture loving indigenous species. Key words: TWINSPAN; vegetation; inland wetland; India DOI: 10.3126/jowe.v3i0.2433 Journal of Wetlands Ecology, (2009) Vol. 3, pp 23-31


Koedoe ◽  
1989 ◽  
Vol 32 (1) ◽  
Author(s):  
N. Hanekom ◽  
A. Southwood ◽  
M. Ferguson

Sampling plots (5 m x 10 m in fynbos, 10 m x 10 m in forest) were analysed in the littoral, coastal escarpment, and north and south facing inland escarp- ment zones of 17 transect sites along the length of the Tsitsikamma Coastal National Park. Cover- abundance values were estimated for each species in the sampling plots. A detrended correspondence analysis (using CANOCO) and a two way indicator species analysis (TWINSPAN) were carried out on these data to determine the communities sampled. The vegetation of the park was classified into an Afromontane Forest, a Littoral Herbland and two Mesic Mountain Fynbos Communities. The distribution and extent of these communities were determined and their conservation discussed.


2013 ◽  
Vol 37 (2) ◽  
pp. 275-287 ◽  
Author(s):  
Suzane Bevilacqua Marcuzzo ◽  
Maristela Machado Araújo ◽  
Solon Jonas Longhi

Este estudo teve por objetivos analisar a estrutura de grupos florísticos na vegetação arbórea-arbustiva de um trecho de encosta de Floresta Estacional Subtropical, no Parque Estadual Quarta Colônia, RS, e determinar fatores ambientais importantes na ocorrência das espécies, a fim de subsidiar programas de restauração de áreas degradadas como ecossistema de referência. Para isso, foi realizado estudo fitossociológico em 12 parcelas de 200 m² (10 x 20 m), distantes 20 m entre si, distribuídas sistematicamente em quatro faixas de 100 m entre si, seguindo gradiente de topografia. Em cada parcela foram realizadas a identificação e a medição da circunferência à altura do peito (CAP) e da altura total dos indivíduos arbóreos e arbustivos, ou seja, com CAP > 15 cm, denominado componente arbóreo. Os dados do sub-bosque foram obtidos em parcelas circulares com raio de 1,78 m, instaladas no centro das parcelas de 10 x 20 m, medindo-se indivíduos com altura > 30 cm e CAP <15 cm. As variáveis ambientais foram compostas pela declividade, pela intensidade luminosa, pelas características químicas e textura do solo. Os dados foram analisados segundo a estrutura e diversidade da vegetação por meio da análise de agrupamento pelo método TWINSPAN (Two-way Indicator Species Analysis) e da ordenação pelo método CCA (Análise de Correspondência Canônica). Foi identificada a formação de dois grupos florísticos. A composição de espécies de cada grupo pertence a diferentes estágios de sucessão natural, conforme histórico de uso agrícola, e, segundo suas características funcionais, podem ser indicadas para programas de restauração florestal.


2012 ◽  
Vol 518-523 ◽  
pp. 5324-5329 ◽  
Author(s):  
Xiang Lin Wang ◽  
Jing Peng Li ◽  
Yan Zhang ◽  
Zhi Yao Su

Distribution pattern of 1148 indigenous tree species in Guangdong province and their relations to the environment were investigated based on the 0.5°×0.5° latitude-longitude grid system. The results showed that indigenous tree species richness increased with increasing latitude. Richness peaked in the middle of the study area with longitudinal gradient. Four ecological areas for indigenous tree species distribution were delimited using cluster analysis and TWINSPAN (two-way indicator species analysis). Indicator Species Analysis showed a significant difference was found in indicator species distribution across latitude gradient and the 4 ecological areas. Northern mountain areas and southern coastal areas possessed most of the indicator species (IV ≥ 0.7), among which Celtis philippensis, Gironniera cuspidata and Symplocos chunii were strongly indicative of the environmental characteristics. The study of distribution patterns and classification of ecological areas, which reflects different geographical and climatic characteristics, will be of significant implications for introduction of indigenous tree species from natural ecological areas.


2021 ◽  
Vol 27 (2) ◽  
pp. 153-162
Author(s):  
Sohaib Muhammad

Multivariate analysis through Two Way Indicator Species Analysis (TWINSPAN) was conducted to study the phytosociological attributes of weeds of some selected crop fields of chickpea, mustard and wheat of Tehsil Isa Khel, District Mianwali, Punjab. Forty one (41) weed species were collected from the study area belonging to twenty one (21) different families. Twenty four weed species found in chickpea, twenty five in mustard and twenty nine in wheat crop fields. Sixteen weed species were common in three crops. Family Poaceae and Astraceae had maximum weed species i.e. 7 and 6 species respectively followed by Euphorbiaceae, Fabaceae, Chenopodiaceae, Papaveraceae, Zygophyllaceae and so on. Asphodelus tenuifolius, Medicago monantha and Carthamus oxycantha are frequently occurring weeds relative to others. Two-Way Indicator Species Analysis (TWINSPAN) was performed on the percentage cover basis which divided the weed species into groups, sub groups, associations and sub associations.


2006 ◽  
Vol 14 (1) ◽  
pp. 17 ◽  
Author(s):  
Roosevelt GARCÍA-VILLACORTA ◽  
Manuel AHUITE-REÁTEGUI ◽  
Mauro OLORTEGUI-ZUMAETA

La Zona Reservada Allpahuayo-Mishana (ZRAM) alberga las áreas más extensas de bosques sobre arena blanca, localmente conocidos como varillales, protegidas actualmente en el Perú. Con el propósito de obtener información que ayude en el manejo y la conservación de este tipo de vegetación, nosotros estudiamos la composición florística, estructura y características ambientales de 44 parcelas, 20 x 20 m, ubicadas en los suelos de arena blanca de la ZRAM, Loreto, Perú (3°53’S, 73°25’O, 110-180 m.s.n.m.). Para la selección de los lugares demuestreo en el área utilizamos una imagen de satélite Landsat TM 5. Seleccionamos los lugares de muestreo, tratando de abarcar la mayor variación posible que podíamos observar en los colores de la imagen de satélite, con el fin de muestrear varillales potencialmente diferentes en el campo. Las parcelas estuvieron ubicadas a lo largo de transectos que atravesaron parches heterogéneos de varillal. En cada parcela registramos, en cinco clases diamétricas, a todos los individuos que tenían al menos un metro de altura e hicimos una estimación de la cobertura herbácea. También medimos la altura del dosel y grosor de la capa orgánica. Realizamos análisis de agrupamiento (cluster analysis), entre las parcelas, usando como variables el número de tallos por parcela, la altura del dosel y la calidad del drenaje expresada por el grosor de la capa orgánica (capa orgánica delgada = buen drenaje, y viceversa). Utilizamos además la abundancia y frecuencia de las especies en los grupos paradefinir especies indicadoras (indicator species analysis). En el contexto de nuestro estudio, y utilizando la terminología regional para estos bosques, reconocemos la existencia de cinco tipos de varillales en la ZRAM: varillal alto seco, varillal alto húmedo, varillal bajo seco, varillal bajo húmedo y chamizal.


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