Sünnet Gölü Çevresinin Bolu, Türkiye Damarlı Bitki Taksonu Gamma
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www.biodicon.com Biological Diversity and Conservation ISSN 1308-8084 Online; ISSN 1308-5301 Print 4/1 (2011) 107-121 Gamma-diversity of vascular plant taxa of the surrounding of Lake Sünnet (Bolu, NW Turkey) compared with other regions in Bolu Nursel İKİNCİ *1 1 Abant Izzet Baysal University, Faculty of Arts and Sciences, Department of Biology, TR-14280 Bolu, Turkey Abstract This paper reports the gamma-diversity of vascular plant taxa (ferns, fern allies and seed plants) of the surrounding of Lake Sünnet (Bolu, Turkey). The vascular flora of the surrounding of Lake Sünnet was compiled from the fieldworks done between 2006 and 2009. The studies resulted in 324 taxa belonging to 67 families and 216 genera. The number of endemic species was found to be 35, corresponding to an endemism ratio of 10.8%. The richest families were Lamiaceae, Asteraceae, Fabaceae, Boraginaceae, and Rosaceae. The richest genera were found as Astragalus, Vicia, Salvia, Centaurea, and Viola. Distribution of the species according to phytogeographical regions resulted in 16.4% as Euro-Siberian elements (including Euxines), 13.3% as Mediterranean elements, and 10.2% as Irano-Turanian elements. The study site was compared with floristic composition of 11 other neighboring regions. TWINSPAN analysis classified 12 sites into four main community types. Detrended Correspondence Analysis (DCA) resulted in three clusters and Gökçeler Mountain. In UPGMA cluster analysis there are two clusters and Gökçeler Mountain was also placed separately. Key words: Bolu, Sünnet, Flora, TWINSPAN, DCA ---------- ∗ ---------- Sünnet Gölü çevresinin (Bolu, Türkiye) damarlı bitki taksonu gamma-çeşitliliği ve Bolu’daki diğer alanlarla karşılaştırılması Özet Bu çalışmada Sünnet Gölü çevresinin (Bolu, Türkiye) damarlı bitki gamma-çeşitliliği araştırılmıştır. Alanın damarlı bitki florası 2006 ve 2009 yılları arasında yapılan arazi çalışmaları sonucu tespit edilmiştir. Çalışma sonucu 67 familya ve 216 cinse ait 324 takson kaydedilmiştir. Alanda tespit edilen endemik türlerin sayısı 35, endemizim oranı ise %10.8 olmuştur. En zengin familyalar Lamiaceae, Asteraceae, Fabaceae, Boraginaceae ve Rosaceae’dır. En büyük cinsler ise Astragalus, Vicia, Salvia, Centaurea ve Viola olmuştur. Türlerin fitocoğrafik alanlara göre dağılımı ise %16.4 Avrupa-Sibirya (Öksin alanını içerecek şekilde), %13.3 Akdeniz ve %10.2 Iran-Turan elementi şeklinde olmuştur. Çalışma alanının floristik bileşimi 11 farklı komşu alanla karşılaştırılmıştır. TWINSPAN analizi karşılaştırılan 12 alanı dört ana komünite tipi altında sınıflandırmıştır. Detrended Correspondence Analizi (DCA), alanları üç farklı küme ve Gökçeler Dağı şeklinde gruplandırmıştır. UPGMA küme analizi sonucu Gökçeler Dağı haricindeki diğer alanlar iki küme altında toplanmıştır. Anahtar kelimeler: Bolu, Sünnet, Flora, TWINSPAN, DCA 1. Introduction Lake Sünnet is located in Bolu province of North Western Turkey at 40˚26.352 N, 30˚57.440 E (Figure 1 and Figure 2). Lake Sünnet is found in A3 square according to geographical divisions in Flora of Turkey (Davis, 1965- 1985). The study area contains the surroundings of the Sünnet Lake and the Sünnet Village (Figure 1). The altitude of * Corresponding author / Haberleşmeden sorumlu yazar: Tel.: 903742541000/1235; E-mail: [email protected] © 2008 All rights reserved / Tüm hakları saklıdır BioDiCon. 162-1110 108 Biological Diversity and Conservation – 4 / 1 (2011) the studied area ranges from 800 m to 1200 m and there is a lake is at 1030 m. The highest peak of the region is at 1470 m and there are several hills around 1450 m (Hoşgören and Ekinci, 2004). The lake is formed by landslides and traces of those landslides are presently visible in the area (Hoşgören and Ekinci, 2004). Sünnet area is 76 km away from Bolu, 16 km from Göynük and 35 km to Mudurnu. There is a hotel near the Lake and as a consequence the area is busy especially at the weekends. Figure 1. Geographical location of the study area In terms of phytogeographical regions, northern part of the Bolu province is in the Euxinian province of Euro- Siberian phytogeographical region, and southern parts in Irano-Turanian phytogeographical region. However, south western parts of the province near the Sakarya river basin have Mediterranean floristic and phytogeographical influence characterized by Pinus brutia Ten. forests. The Mediterranean phytogeographical region is represented in NW Turkey mainly along the Black Sea coast and in the inner parts where the Sakarya River and small streams contributing to it form deep valleys. The altitude in this area can descend as low as 240 m. Because of this the study area lies on the intersection of the three phytogeographical regions (Davis, 1971). Figure 2. Geographical location of the study area and compared 11 sites. Detailed information about each region is given in Table 1 Nursel İKİNCİ, Gamma-diversity of vascular plant taxa of the surrounding of Lake Sünnet (Bolu, NW Turkey) compared with other regions in Bolu Biological Diversity and Conservation – 4 / 1 (2011) 109 In terms of geology of the area, during the early Jurassic terrestrial areas were underwater. Oldest formations in the area are limestone from the early Cretaceous period. The area was deeper during the Late Cretaceous. During Paleocene, region became shallower and even terrestrial again. Later, terrestrial areas were protected since Late Eocene- Oligocene. The present structure of the area is a result of terrestrial erosion since Paleocene (Oral, 1985). Climatic data were obtained from Bolu Meteorological station which is at 742 m altitude, with coordinates 40°44’ E and 31°31’ N. According to the meteorological data gathered between 1975 and 2009 (35 years) mean annual precipitation for Bolu is 454 mm and the mean annual temperature is 10.4 °C. Mean maximum temperatures are highest in July as 19.7 °C. Mean lowest temperatures recorded in January as 0.9 °C. Highest rainfall is received in December and the lowest rainfall is in August and September. Figure 3 shows the climatic diagram of Bolu. Bolu is basically under the influence of Western Black Sea and Black Sea climate. However, western and south western parts have Marmara and Central Anatolian climate. Therefore, Bolu occupies a transition zone of different types of climates. Southern parts of Bolu have higher elevations and decreased precipitation and a continental climate (Bolu Yıllığı, 1998). The study of Sensoy et al. (2008) showed that Sünnet Area has C1 Semidry-Less humid climate according to Thornthwaite climate classification. Figure 3. Climatic diagram of Bolu, Turkey. Data obtained from Bolu Meteorological station between 1975 and 2009. The natural vegetation in the area is mainly composed of Pinus nigra subsp. nigra var. caramanica forests with a sparse underground vegetation cover. There are also rocky scrub composed of Paliurus spina-christii, Cornus mas and Corylus avellana var. avellana bushes. There are marshy habitats around the lake and along the small tributaries in the area. There are different measures of biodiversity. Alpha-diversity (within habitat diversity) concerns different groups of organisms interacting and competing for the same resources or sharing the same environment (Whittaker, 1972). Beta-diversity (between-habitat diversity) is the response of organisms to spatial heterogeneity and is expressed in terms of similarity index between communities. Both alpha and beta-diversity contributes to Gamma-diversity which is concerned about species richness on the regional scale (Whittaker, 1972). Gamma-diversity described for vascular plants of a region corresponds to local floras. Davis (1975) stated that Bolu is among the moderately known areas in terms of plant biodiversity though several studies dealing with the flora and vegetation of the area have been published ever since (see Table 1). Nevertheless, there is no floristic or vegetation analysis so far known from the surroundings of Lake Sünnet. Therefore, the aims of the present study are to determine the gamma-diversity of vascular plants of the surrounding of Lake Sünnet and to compare it with species composition of the neighbouring sites. 2. Materials and methods The floristic inventory was generated by several fieldworks from March to end of October between 2006 and 2009. During the identification of the plant specimens, "Flora of Turkey and the East Aegean Islands (Davis, 1965- 1985; Davis et al., 1988; Güner et al., 2000) was used as a main reference source. Doubtful identifications were checked from "Flora Europaea" (Tutin et al., 1964-1980). Voucher specimens are deposited in the herbarium of Abant İzzet Baysal University (AIBU). Authors of plant names are abbreviated according to Brummitt and Powell (1992). There are disturbed areas around the hotel and farm house immediately on the edges of the lake and in the nearby Sünnet village. Cultivated and naturalized plants from these disturbed areas were not included in the floristic list. Nursel İKİNCİ, Gamma-diversity of vascular plant taxa of the surrounding of Lake Sünnet (Bolu, NW Turkey) compared with other regions in Bolu 110 Biological Diversity and Conservation – 4 / 1 (2011) 2.1. Data Analysis The presence/absence matrix was created containing species list of 12 regions in Bolu. Detailed information about the analyzed 12 regions is given in Table 1 and their geographical positions are indicated in Figure 2. It was not possible to compare the sizes of the 12 regions because detailed information about the boundary of study area was lacking in