scholarly journals Relationships between topographic factors, soil and plant communities in a dry Afromontane forest patches of Northwestern Ethiopia

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247966
Author(s):  
Liyew Birhanu ◽  
Tamrat Bekele ◽  
Binyam Tesfaw ◽  
Sebsebe Demissew

Plant community types are influenced by topographic factors, the physical and chemical properties of soil. Therefore, the study was carried out to investigate the relationships of soil and topographic factors on the distribution of species and plant community formation of the Dega Damot district in Northwestern Ethiopia. Vegetation and environmental data were collected from 86 plots (900 m2). Agglomerative hierarchical cluster analysis and redundancy analysis (RDA) with R software were used to identify plant communities and analyze the relationship between plant community types and environmental variables. Five plant community types were identified: Erica arborea-Osyris quadripartita, Discopodium penninervium-Echinops pappii, Olea europaea -Scolopia theifolia, Euphorbia abyssinica-Prunus africana, Dodonaea anguistifolia-Acokanthera schimperi. The RDA result showed that the variation of species distribution and plant community formation were significantly related to altitude, organic matter, moisture content, slope, sand, pH, EC, total nitrogen and phosphorus. Our results suggest that the variation of plant communities (Community 1, 2, 3, and 4) were closely related to environmental factors, including altitude, moisture content, OM, slope, sand, pH, EC, soil nitrogen, and phosphorus, among which altitude was the most important one. However, all the measured environmental variables are not correlated to Dodonaea anguistifolia-Acokanthera schimperi community type. Therefore, it can be concluded that some other environmental variables may influence the species composition, which is needed to be further investigated.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mesfin Belete Hailemariam ◽  
Tamru Demsis Temam

Vegetation-environment relationships are usually studied along elevational gradient. The patterns of plant community distribution in Gole forest, Ethiopia, were studied along elevational gradient and disturbances. Disturbances were recorded following the elevational gradient. For vegetation data collection, 62 sample plots of size 20 × 20 m were established along an elevational gradient (2728–3480 m.a.s.l). Data on species composition and environmental variables were measured and recorded in each plot. The elevation of each sample plot was measured using Garmin GPS. Anthropogenic disturbances in each plot were estimated using the following scales: 0 = no disturbance, 1 = slightly disturbed, 2 = moderately disturbed, and 3 = highly disturbed. R statistical package was used for cluster and ordination analysis. Boxplots and analysis of variance were used to assess the relationships between plant communities and environmental variables. Sorensen’s similarity coefficient was used to detect similarities and dissimilarities among communities. A total of 114 plant species belonging to 57 families and 94 genera were identified. Five plant community types were identified using agglomerative hierarchical cluster analysis. Every plant community had differences in composition and environmental variables. The variation in plant community distributions was significantly related to elevation and disturbance. Plant community distribution was negatively correlated with elevation ( P < 0.05 ) and also with disturbance ( P < 0.05 ). Sorensen’s similarity index showed that there was a difference in the distribution of plant species composition among the communities. The difference in plant community distribution of Gole forest was significantly related to elevation. Disturbances also have a considerable influence on the plant communities and mitigation of disturbance should be the main measure that needs to be taken into account in conservation planning in the study area.


1998 ◽  
Vol 20 (1) ◽  
pp. 119 ◽  
Author(s):  
B Fergusson ◽  
AJ Graham

The soil and plants at a 27.4 ha field site near Kalgoorlie, Western Australia, were surveyed and analysed with multivariate statistics. Cluster analysis identified four distinct plant communities at the study site. These were: Acacia acuminata shrubland Eucalyptus gvfithsii woodland Eucalyptus salrnonophloia woodland 'Ground Covers' - areas characterised by the presence of generalist herbs, low shrubs and weeds, and the absence of dominant upper storey species. Discriminant function analysis identified site elevation and soil exchangeable Ca as the primary environmental discriminants between the plant communities. Using these two variables, sample points were classified into one of the four plant communities. The two methods of classification matched well, with classification based on the two environmental variables providing an indication of which plant community would be most likely to establish in disturbed areas. This type of information can be important to revegetation programs in the region, guiding the use of appropriate plant species under different rehabilitation conditions. Key wcrds: environmental variables, plant communities, multivariate analysis, classification, revegetation


2020 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 × 25 m (625 m2) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5 m were recorded in 25 m X 25 m plots. Within the major plots, five 3 m x 3 m subplots (9 m2) was used to collect shrubs with dbh < 2.5 cm and > 1.5 m height. Within each 9 m2subplots, two 1 m2 subplots were used to collect data on the species and abundance of herbaceous plants. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to EC and K. Conclusions The studied forest can play a significant role in biodiversity conservation since it harbours high species diversity and richness. Thus, all Stakeholders including Oromia Forest and wildlife enterprise (OFWE) and the regional government should work to designate the forest as a biosphere reserve and being registered under UNESCO.


2019 ◽  
Vol 11 (18) ◽  
pp. 4879
Author(s):  
Kaidi Zhang ◽  
Yuan Gong ◽  
Hao Fa ◽  
Min Zhao

Shanghai, China, is a city that is relatively representative of various cities in China due to its geographical location and socio-economic dynamics. The role of urban vegetation in the carbon cycle of urban developments in these types of cities is now being studied. We focus on identifying which urban plant community types have a greater influence on CO2 flux in cities, thus providing a scientific basis for low-carbon urban greening. Based on the eddy covariance (EC) observation system, ART Footprint Tool, plant inventory, and ecological community classification, we show that the CO2 flux characteristics of different plant communities vary temporally. The carbon sink duration during summer was the longest (up to 10 h) and the carbon sink duration was the shortest during winter (7.5 h). In addition, we discovered that the CO2 flux contribution rates of different plant community types are distinct. The annual average CO2 contribution rates of the Cinnamomum camphora-Trachycarpus fortunei community and the Metasequoia glyptostroboides+Sabina chinensis community are 11.88% and 0.93%, respectively. The CO2 flux contribution rate of the same plant community differs according to season. The CO2 contribution rate of the Cinnamomum camphora-Trachycarpus fortunei community exhibits local maxima during winter and summer, with a maximum difference of 11.16%. In contrast, the Metasequoia glyptostroboides+Sabina chinensis community has a CO2 contribution rate of 0.35% during the same period. In general, summer is the season with the lowest CO2 flux contribution rate of plant communities, and winter is the season with the highest CO2 flux contribution rate. However, the Cinnamomum camphora+Salix babylonica community and the Cinnamomum camphora+Sabina chinensis community present the opposite pattern. Finally, the diurnal variation characteristics of CO2 flux in different communities have the same trend, but the peak values differ significantly. Overall, daily CO2 flux peak value of the Metasequoia glyptostroboides community and the Cinnamomum camphora-Trachycarpus fortunei community indicate that these two plant communities exhibit a strong capacity for CO2 absorption in the study area. According to these research results, urban greening efforts in subtropical climates can increase the green space covered by the Cinnamomum camphora-Trachycarpus fortunei and the Metasequoia glyptostroboides community types when urban greening, so as to appropriately reduce the CO2 emitted into the atmosphere.


1989 ◽  
Vol 67 (4) ◽  
pp. 1126-1136 ◽  
Author(s):  
M. Muc ◽  
B. Freedman ◽  
J. Svoboda

A cluster analysis was used to apportion 136 stands in a High Arctic lowland among six vascular plant community types. These communities are described on the basis of the average prominence values of vascular species and the total cover of macroalgae, bryophytes, lichens, and vascular plants within the designated clusters of stands. The relationships among the community types was explored by a detrended correspondence analysis. The ordination of stands showed considerable floristic overlap among the most widespread plant communities on the lowland. This largely reflects the microtopographic heterogeneity of the sites, the relatively depauperate flora of the High Arctic, and the considerable ecological amplitude of the most prominent vascular plant species.


Author(s):  
Ram C. Sharma ◽  
Hidetake Hirayama ◽  
Masatsugu Yasuda ◽  
Miki Asai ◽  
Keitarou Hara

Classification and mapping of plant communities is an essential step for conservation and management of ecosystems and biodiversity. We adopt the Genus-Physiognomy-Ecosystem (GPE) system developed in previous study for satellite-based classification of plant communities. This paper assesses the potential of multi-spectral and multi-temporal images collected by Sentinel-2 satellites. This research was conducted in five representative study sites in a temperate region. It consists of 44 types of plant communities including a few land cover types as well. The plant community types were enumerated in the study sites and ground truth data were prepared with reference to extant vegetation surveys, visual interpretation of high-resolution images, and onsite field observations. We acquired all Sentinel-2 Level-1C product images available for the study sites between 2017-2019 and generated monthly median composite images consisting of ten spectral and twelve spectral-indices. Gradient Boosting Decision Trees (GBDT) classifier was employed as an efficient and distributed gradient boosting technique for the supervised classification of big datasets involved in the research. The cross-validation accuracy in terms of kappa coefficient varied from 87% in Oze site with 41 land cover and plant community types to 95% in Hakkoda site with 19 land cover and plant community types; with average performance of 91% across all sites. In addition, the resulting maps demonstrated a clear distribution of plant community types involved in all sites, highlighting the potential of Sentinel-2 multi-spectral and multi-temporal images with GPE classification system for operational and broad-scale mapping of land cover and plant communities.


2020 ◽  
Author(s):  
José Ramón Martínez Batlle ◽  
Yntze van der Hoek

AbstractDespite being increasingly threatened by human-induced disturbances, dry forests remain the least studied and protected forest types in the Caribbean region. In contrast to many other forest systems in the world, we have little knowledge of the site-specific variation in vegetation communities within these forests, nor understand how plant species distribution is determined by environmental variables, including among them geological attributes. Here, we assessed the associations between plant communities and habitat types in a semi-deciduous forest of the Dominican Republic. We collected vegetation data from 23 sites within the Ocoa river basin, which we classified into six groups with a Random Forest algorithm, lithology, geomorphology, topography, and last decade history of forest loss as predictor variables. We established three main clusters: one group which encompassed sites with forest over a limestone substrate, four groups of sites with forests over a marlstone substrate with varied degrees of steepness and forest loss history, and one group that gathered all sites with forest over an alluvial substrate. In order to measure the associations of plant communities with groups of sites, we used the indicator value index (IndVal), which indicates whether a plant species is found in one or multiple habitat types, and the phi coefficient of association, which measures species preferences for habitats. We found that 16 species of woody plants are significantly associated with groups of sites by means of their indices. Our findings suggest that the detection of plant species associations with our selection of environmental variables is possible using a combination of indices. We show that there is considerable variation in plant community composition within the semi-deciduous forest studied, and suggest that conservation planning should focus on protection of this variation, while considering the significance and variability of geodiversity as well. In addition, we propose that our indicator groups facilitate vegetation mapping in nearby dry forests, where it is difficult to conduct thorough vegetation or environmental surveys. In short, our analyses hold potential for the development of site-specific management and protection measures for threatened semi-deciduous forests in the Caribbean.


2021 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background: This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 X 25m (625m2) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5m were recorded in 25 m X 25 m plots. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result: One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Of these, 52 species (28.9%) were trees, 6 species (3.33%) were Trees/shrubs, 31 species (17.22%) were shrubs, 76 species (42.22%) were herbs, and 15 species (8.33%) were Lianas. Rubiaceae, Acanthaceae and Asteraceae were the richest family each represented by 11 genera and 11 species (6.11%), 9 genera and 11 species (6.11%), 6 genera and 11 species (6.11%), respectively of total floristic composition. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to Electrical Conductivity and Potassium. Conclusions: Description of floristic diversity of species in Gerba Dima forest revealed the presence of high species diversity and richness. The presence of endemic plant species in the study forest shows the potential of the area for biodiversity conservation.


2020 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background: This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 X 25m (625m 2 ) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5m were recorded in 25 m X 25 m plots. Within the major plots, five 3m x 3m subplots (9m 2 ) was used to collect shrubs with dbh < 2.5 cm and > 1.5m height. Within each 9m 2 subplots, two 1m 2 subplots were used to collect data on the species and abundance of herbaceous plants. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result: One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to EC and K. Conclusions: The studied forest can play a significant role in biodiversity conservation since it harbours high species diversity and richness. Thus, all Stakeholders including Oromia Forest and wildlife enterprise (OFWE) and the regional government should work to designate the forest as a biosphere reserve and being registered under UNESCO. Keyword s: Gerba Dima; Indicator species; Moist Afromontane Forest; Species diversity


2020 ◽  
Vol 58 (1) ◽  
pp. 21-31
Author(s):  
Mengistu Teshome ◽  
Zebene Asfaw ◽  
Gemedo Dalle

Abstract For forest ecosystem management to be effective, explicit understanding of the species diversity-environmental relationship along elevation gradient is crucial. This study aimed at identifying and describing plant communities and also documenting their species diversity. Evaluation of relationships between selected environmental variables and species diversity was another objective of this study. Systematic sampling techniques were used to collect vegetation data in a total of forty two sample plots (size=20×20 m). Within main plots, four sub-plots of 5×5 m were established at four corners and – one sub-plot of the same size in the center. These plots were used for shrub and herb diversity assessment. Within each sample plot, all plant species were documented and their scientific names were identified. Environmental variables, such as: elevation, aspect and slope, were also recorded for each main plot. Species diversity was determined using Shannon-Wiener diversity index and evenness in R statistical software. Agglomerative hierarchical clustering method was used for plant community classification. The total of 44 plant species belonging to 30 families was documented. Four plant community types were identified with different diversity, evenness and species richness. These plant communities were: Afrocurpus falcatus-Ficus sur, Maesa lanceolata-Bersama abyssinica, Vernonia myriantha-Urera hypselodendron and Croton machrostachus-Tecleanobilis occurring at average elevation of 2521, 2429, 2329, and 2364 m asl, respectively. Maesa lanceolata-Bersama abyssinica community type exhibited the highest species diversity and evenness followed by Croton machrostachus-Teclea nobilis community type showing the fact that median elevation ranges were rich in species. Elevation and slope gradient explained significant variation in species richness in the studied forest. For effective conservation of biodiversity and sustainable management of the forest ecosystem, further research on the impacts of anthropogenic disturbances and soil properties is recommended as a result of this study.


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