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1

Identification of driving factors for presence of endemic species in the Aglasun district of the Mediterranean Region, Turkey

100%
Ozkan K.
Polish Journal of Ecology
|
2012
|
tom 60
|
nr 2
This study was addressed to environmental factors significantly influencing the habitat preferences of endemic species and to obtain a model of their common habitat preferences in the Aglasun district. The district, covering an area of 55,000 hectares, is located in the lakeland subregion of the Mediterrranean region, Turkey. Data were collected from 199 sample plots (20 × 20 m ) and in total 40 endemic taxa was recorded in 124 plots which include minimum one endemic species. Wilcoxon rank-sum statistic and Pearson chisquared tests were used for continuous and categorical explanatory variables, respectively. The factors playing important roles in habitat preferences of endemic species were following: altitude, radiation index, soil texture, landscape position and landform. Generalized additive model was used for modelling the habitat preferences of endemic taxa. To obtain the best model, all significant environmental factors were evaluated by selecting stepwise option. Finally, the best model was obtained (training AUC = O.816, and crossvalidation AUC = 0.800) by using altitude and landform variables.
2

Using the non-parametric classifier CART to model lebanon cedar (Cedrus libani A. Rich) distribution in a mountain Mediterranean Forest District

100%
Ozkan K.
Polish Journal of Environmental Studies
|
2013
|
tom 22
|
nr 2
This study was conducted to define indicator species of Lebanon cedar (Cedrus libani A. Rich) and to build its potential distribution model in the Yukarigokdere Forest District of Turkey’s Mediterranean region. In the study, the data were collected from 119 sample plots. To define indicator species of Lebanon cedar, interspecific correlation analysis (ICA) was employed. The findings obtained from ICA showed that thermoMediterranean elements (Pistacia terebinthus subsp. palaestina, Quercus coccifera, and Styrax officinalis) are the most significant negative indicator species of Lebanon cedar, while Its most significant positive indicator plants are supra- and mountain-Mediterranean elements (Acer hyrcanum subsp. sphaerocaryum, Berberis crataegiana, Amelanchier parviflora, Fraxinus ornus subsp. cilicica, and Sorbus umbellate). By using climatic and topographical data as explanatory variables, visual assessment of the potential distribution probability of Lebanon cedar based on classification and regression technique (CART) was performed. Ten-fold cross validation was run for selection of the optimal tree. The variables building the tree model were elevation, head index, annual precipitation, slope degree, landform category, and topographical position index. Among them, elevation was found to be the most significant factor on the distribution of Lebanon cedar.
3

Predicting the potential distribution of plant diversity in the Yukarigokdere forest district of the Mediterranean region

63%
Ozkan K., Berger U.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 3
Biodiversity is of crucial importance for ecosystem health and functioning. It is thus one of the most important topics in forest ecology. This study focuses on modelling the spatial distribution of vascular plant diversity (H), richness (S) and evenness (E) in the Yukarıgökdere forest district (14667 ha) located in transition zone between Mediterranean and continental climates in the Mediterranean region, Turkey. Species abundance was sampled at 95 sample plots extending from 1000 to 1900 m a.s.l. in order to calculate the response variables (H, S, E). Climatic and topographical data served as explanatory variables. Multiple regression (ML) and classification and regression tree technique (CART) were used to obtain the distribution models of response variables. The better results were provided by CART. That is why visual assessments of the predicted values of the response variables based on (CART) were performed. The explained variances of the model trees were 63.4, 63.1 and 44.5% for H, S and E respectively. Elevation was found to be the most important environmental factor for all response variables. The higher H and S values were found at the east lower part (1000-1150 m a.s.l.) and the west upper part (1500–1800 m a.s.l.) of the district. The evenness (E) shows generally higher relative values in the upper part of the area. The lowest E specifies the area being optimal for tree growing. It is located between 1400 and 1500 m a.s.l., and ranges from the north to the south in the district.
4

Ecological land classification and mapping based on vegetation-environment hierarchical analysis - a case study of Buldan forest district (Turkey)

63%
Ozkan K., Gulsoy S.
Polish Journal of Ecology
|
2010
|
tom 58
|
nr 1
Distinction of the geographic areas intended for hierarchical sequence of vegetation classes involves the hierarchical classification of ecosystems. In this context, it is essential to determine the effective environmental characteristics at each hierarchical level of vegetation distinction. The study was carried out in order to classify and hierarchical mapping the Buldan forest district (area 190,000 km², altitude 400–1400 m a.s.l. covered in 40% with Mediterranean pine and oak forest, in 60% – by arable and pasture land). 56 sample plots (20 m × 20 m) were taken. At each sample plot, environmental characteristics (56 variables) and vascular plant species (108 species in total) were recorded. The relationships between environmental variables and the distribution of plants (presence/absence) were investigated by two hierarchical approaches for both of floristic data matrix and environment matrix by using cluster analysis, stepwise discriminate analysis and chi square test. Interspecific correlation analysis was also applied to determine the indicator species at each level of divisions. Two subdistricts were distinguised: Ortakcı-Cagir subdistrict (characteristic species association with Pinus brutia, Pistacia terebinthus, Nerium oleander, Ficus carica, Olea europea) and Suleymanli subdistrict (species association with Pinus nigra, Cistus laurifolius, Prunus divarcata and Rosa canina). Two sections in Suleymanli subdistrict were distinguished: Kocaalan section with characteristic association of Pinus nigra, Cistus laurifolius, Drypteris pallida and Ericek section – characterized with an association of Creategus monogina, Astragalus sp. and Pistacia terebintus. The altitude was the fundamental variable affecting on site classification at the level of subdistrict. Longitude was the most important variable affecting on discrimination of the sections of Suleymanli subdistrict. This local study offers a model including statistical processes which can be applied to the other forest areas for large scale classification of vegetation and environmental relations. Application of this model based on hierarchical classification of ecosystem units is also important for estimation of the changes of natural vegetation in ecosystems in the future due to global climatic change.
5

Endemic plant species in a karstic canyon [Mediterranean Region, Turkey]: relation to relief and vegetation diversity

63%
Ozkan K., Suel H.
Polish Journal of Ecology
|
2008
|
tom 56
|
nr 4
709-715
Data collected from 85 sample plots in Yazili Canyon Nature Park (deep, limestone valley; length - 6 km, area – 600 ha, height – 100–400 m) located in Mediterranean region (Turkey) yielded 24 endemic vascular plants. The endemic plant diversity and all vascular plant diversity indices were calculated for each sample plot using Simpson index. Regression analysis was performed between environmental factors, plant diversity and canopy closure. Endemic plant diversity showed a positive correlation with vascular plant diversity, and a negative correlation with slope position and altitude. A significant quadric relationship was observed between the endemic plant diversity and aspect variable. RDA (redundancy analysis) and CCA (canonical correspondence analysis) based on linear regressions were applied to determine the environmental factors affecting the distribution of endemic species, and the best model based on total variance explained was selected. According to RDA based on linear regression, habitat selection of endemics is strongly correlated with aspect, slope position and altitude. Lower altitude zone (300–500 m), the north aspect and lower slope including valley bottom of Yazili canyon were observed to be the most suitable areas for endemics.
6

Key factors in the site selection of Rosa canina (L.) – applying the generalized additive model

51%
Guner S. T., Ozkan K., Comez A.
Polish Journal of Ecology
|
2011
|
tom 59
|
nr 3
Determining suitable sites for species is of great importance in the choice of plant species to be used for ecosystem restoration. The number of plant species to be used in restoration of degraded ecosystems is restricted by climate in arid and semi arid regions. Planting with economically important species in addition to ecological aspects is preferred by decision makers in Mediterrenian countries including Turkey. This study was addressed to determine the significant environmental factors influencing the distribution of dog rose hip (Rosa canina) and to obtain its distribution model. The study was carried out in an area of 26,400 km2 in The Inner Anatolia which has semiarid climate. 106 sample plots, 20 x 20 m in size, were selected from different sites with and without Rosa canina in the summer of 2007. Wilcoxon rank-sum statistic for continuous variables and Pearson Chi-square tests for categorical variables were applied. Altitude, slope degree, available water capacity, soil reaction and soil K, Ca, Mg content as well and total calcium carbonate amount as the continuous variables and northwest- northeast group of aspect, metamorphic group of bedrock as the categorical variables were determined as the significant factors influencing the presence of dog rose. Generalized Additive Model (GAM) was performed for modeling the distribution of the species. To obtain the best model, all significant environmental factors were evaluated. The best model result was obtained (training Area Under Curve (AUC) = 0.902 and cross-validation AUC = 0.841) by means of altitude, slope degree, aspect, and bedrock. Interspecific correlation analysis (ICA) was applied to define indicator species accompanying the dog rose. Dog rose distribution was positively correlated with Cistus laurifolius, Pyrus elaeagnifolia, Lonicera caucasica subsp. orientalis, Quercus vulcanica and Amelanchier rotundifolia subsp. Rotundifolia. The results obtained from this study are crucial for estimation of the suitable areas for Dog rose in restoration studies of natural ecosystems in the Mediterranean region, including Anatolia in Turkey.
7

Changing the potential distribution of Turkey oak (Quercus cerris L.) under climate change in Turkey

51%
Mert A., Ozkan K., Senturk O., Negiz M. G.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 4
Turkey oak (Q. cerris) is an important species for rehabilitating soils, promoting conservation, and increasing biodiversity. It is also a fire-resistant plant. To predict the potential distribution of this species under climate change is crucial for better understanding the future of ecosystems – in particular Mediterranean ecosystems. The purpose of this study was to generate the potential distribution maps of Turkey oak under current and changing climate in the Sütçüler district located in the translation zone of the Mediterranean region. Classification and regression tree technique (CART) was applied to model the distribution of the species (response data) using current climatic data, parent material, landform types, and topographical position index (explanatory data). Geographic information system (GIS) was used for visualizing current potential distribution of the species. Next, the obtained distribution model was simulated to the digital data of climatic change scenario b2 of IPCC. In this way, changing the potential distribution of Turkey oak along the district was predicted under climate change.
8

First report on the molecular detection, phylogeny, virological and pathological investigations of Avibacterium paragallinarum in chickens in Turkey

27%
Umar S., Ongor H., Bayraktar E., Ozturk Gurgen H., Sigirci B. D., Satir E., Ozkan K., Turan N., Yilmaz A., Gurel A., Ak S., Cetinkaya B., Yilmaz H.
Medycyna Weterynaryjna
|
2020
|
tom 76
|
nr 04
Avibacterium paragallinarum is an important pathogen affecting the respiratory tract of chickens. There is a paucity of information on the molecular characteristics and pathology of A. paragallinarum in Turkish poultry flocks. In the present study, broiler and layer flocks (n = 2) suspected of viral infections with serious respiratory signs and significant mortality were visited. Chickens showed various disease signs and necropsy lesions, including purulent nasal discharge, respiratory distress, facial edema, sticky eyes, mucoid tracheitis, hemorrhagic inflammation of the infraorbital sinuses along with fibrinous mass and conjunctivitis. Histopathological lesions included loss of cilia along with necrosis and exfoliation of the superficial mucosal epithelium of the trachea, facial cellulitis, dermatitis, fibrinous plasmatic edema and infiltration of inflammatory cells, especially heterophils. A. paragallinarum was detected in tissue samples by species-specific polymerase chain reaction (PCR). The sequencing and phylogenetic analysis of the core region of the hemagglutinin (HA) gene revealed that Turkish strains detected here belonged to serotype A (serovar A1). They were related to strains reported from India (VRDC), the United States (0083), and Japan (0221), which are representatives of serovar A1. A homology of 88-90% was found between Indian strains and the Turkish strains detected in this study. Surprisingly, only vaccine strains of infectious bronchitis virus (IBV) were detected as a co-infecting agent in all samples positive for A. paragallinarum. Our findings suggest that A. paragallinarum may be an emerging pathogen in Turkish poultry flocks, and direct PCR may facilitate rapid diagnosis of infectious coryza. These results will also help to develop control strategies for A. paragallinarum.
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