Gölcük köyü ve çevresinin (Kestel, Bursa) florası = Flora of the village of Gölcük and its surroundings (Kestel, Bursa)

Abstract

Bu çalışmada Bursa ilinin kuzeydoğusunda, Kestel ilçesi sınırları içerisinde yer alan Gölcük Köyü ve çevresinin floristik özellikleri belirlenmeye çalışılmıştır. Davis'in Grid Sistemine göre A2 karesinde yer alan araştırma sahasında, 2022-2023 yılları arasında gerçekleştirilen 19 arazi çalışması sonucunda toplam 519 bitki örneği toplanmış ve bu süreçte bitkilerle ilgili 2258 adet fotoğraf çekilmiştir. Bitkiler, mümkün olduğunca çiçekli veya meyveli oldukları dönemlerde toplanarak fotoğraflanmış; ardından mevcut kurallara uygun şekilde preslenip kurutulmuştur. Kurutulan örnekler, böcek gibi zararlılardan korunmak amacıyla soğutucuda muhafaza edilerek herbaryum materyaline dönüştürülmüştür. Toplanan bitki örneklerine, araziden toplanma sırasına göre herbaryum numarası verilmiş; bu numaralarla birlikte habitat özellikleri, toplanma tarihleri, deniz seviyesinden yükseklikleri ve koordinat bilgileri arazi defterine kaydedilmiştir. Bu çalışmalarda, Gölcük Köyü ve çevresinde 69 familyaya ait 229 cins ve 378 tür ile alt tür seviyesinde takson tespit edilmiştir. Bu taksonların 3 tanesi Pteridophyta, 375 tanesi Spermatophyta divizyosu üyesidir. Spermatophyta divizyosuna ait taksonların 4 tanesi Gymnospermae alt divizyosu; 371 tanesi Angiospermae alt divizyosu üyesidir. Angiospermae alt divizyosundan geriye kalan bitkilerin ise 333 tanesi Dicotyledonae ve 38 tanesi Monocotyledonae sınıfına aittir. Araştırma alanında en fazla cins çeşitliliğine sahip ilk 5 familyaya: Asteraceae 36 farklı cinsle (%15,72), Apiaceae 15 farklı cinsle (%6,55), Brassicaceae 14 farklı cinsle (%6,11), Fabaceae 12 farklı cinsle (%5,24), Lamiaceae 11 farklı cinsle (%4,80), Rosaceae 10 farklı cinsle (%4,37), Poaceae 10 farklı cinsle (%4,37), Ranunculaceae 8 farklı cinsle (%3,49), Liliaceae 8 farklı cinsle (%3,49) ve Boraginaceae 7 farklı cinsle (%3,06) ev sahipliği yapmaktadır. Araştırma alanında tespit edilen tür ve tür altı takson bakımından en zengin ilk 5 familya şunlardır: Asteraceae 58 takson (%15,34), Fabaceae 33 takson (%8,73), Rosaceae 23 takson (%6,08), Lamiaceae 23 takson (%6,08), Brassicaceae 17 takson (%4,50), Apiaceae 17 takson (%4,50), Ranunculaceae 16 takson (%4,23), Liliaceae 13 takson (%3,44), Poaceae 13 takson (%3,44), Scrophulariaceae 11 takson (%2,91). Alandaki takson bakımından en zengin cinsler ise 8 takson ile Trifolium (%2,12), 6 takson ile Medicago (%1,59), 6 takson ile Ranunculus (%1,59), 5 takson ile sırasıyla; Rumex (%1,32), Geranium (%1,32), Vicia (%1,32), Quercus (%1,32), 4 takson ile sırasıyla; Alyssum (%1,06), Malva (%1,06), Lathyrus (%1,06)'dur. Taksonların fitocoğrafik bölgelere göre dağılımı ve oranları şu şekildedir: Akdeniz elementine ait olanlar 63 takson (% 16.67), Avrupa-Sibirya elementine ait olanlar 50 takson (% 13,23), İran-Turan elementine ait olanlar 5 takson (% 1.32), ve çok bölgeli ya da bölgesi belirlenemeyenler ise 260 takson (% 68.78) olarak kaydedilmiştir. Çalışma alanı Akdeniz ve Avrupa-Sibirya fitocoğrafik bölgeleri arasında bir geçiş bölgesinde olup, bu durum farklı bitki türlerinin karışımını içermesine olanak tanır. İklim ve topografik çeşitlilik, bu bölgede çeşitli bitki türlerinin bir arada bulunmasını destekler. Geçiş bölgeleri, biyolojik çeşitlilik açısından zengin oldukları için, hem Akdeniz fitocoğrafik bölgesinin hem de Avrupa-Sibirya fitocoğrafik bölgesinin bitki türleriyle birlikte İran-Turan fitocoğrafik bölgesine ait bitki türlerini de barındırır. Fitocoğrafik bölgeler arasındaki bağlantılar, İran-Turan Fitocoğrafik Bölgesi'nin bitki türlerinin bu alanlara yayılmasını sağlar. Bu faktörler, çalışma alanında İran-Turan fitocoğrafik bölgesi'ne ait bitki türlerinin varlığını açıklamaktadır. Araştırma alanında yer alan taksonların hayat formlarına göre sınıflandırması şu şekildedir: Fanerofit, 48 takson (%12,70); Kamefit, 19 takson (%5,03); Hemikriptofit, 147 takson (%38,89); Kriptofit, 38 takson (%10,05); Terofit, 124 takson (%32,8); ve Vasküler parazit, 2 takson (%0,53). Endemik takson sayısı 4 olup alanın endemizm oranı %1.06 olarak belirlenmiştir. Çalışma alanımızdaki endemizm oranı, ülkemiz genel endemizm oranına kıyasla oldukça düşüktür. Özellikle son dönemde popüler hale gelen hobi bahçelerinin yaygınlığı, insanların doğaya yönelme ve organik tarım yapma arzusu nedeniyle tarım arazisi oluşturmak amacıyla doğal bitki örtüsünün tahrip edilmesine neden olmaktadır. Bu durum, habitatların zarar görmesine ve dolayısıyla endemik bitki türlerinin azalmasına yol açmaktadır.

In this study, the floristic characteristics of Gölcük Village and its surroundings, located within the boundaries of the Kestel district in the northeast of Bursa province, were attempted to be determined. In the research area located in grid square A2 according to Davis's Grid System, a total of 519 plant specimens were collected, and 2258 photographs of plants were taken during 19 field studies conducted between 2022 and 2023. The plants were collected and photographed, preferably during their flowering or fruiting periods; then, they were pressed and dried in accordance with existing rules. The dried specimens were preserved in a refrigerator to protect them from harmful pests and converted into herbarium material. A herbarium number was assigned to each collected plant specimen according to the order of collection in the field, and along with these numbers, habitat characteristics, collection dates, elevations above sea level, and coordinate information were recorded in the field notebook. The study area consists of mountainous regions, plains where agricultural land is widespread, and wetlands such as ponds and streams. This area, located at a point where ophiolitic suture zones are separated and three important tectonic units intersect, is surrounded by the Istanbul Zone to the north, the Sakarya Zone in the middle, and the Tavşanlı Zones to the south. The basic formations of the research area are formed by Mesozoic formations, namely the Karakaya Group, Bayırköy Formation, Bilecik Limestone, Vezirhan Formation, Gölpazarı Group, and Paşayayla Formation, which are widespread in the east and northeast. Bursa and its surroundings have been folded and fractured by orogenic and epirogenic movements during geological processes, mostly taking their present form during the Quaternary period. This region, located between the southern and middle branches of the North Anatolian Fault, is characterized by an east-west trending tectonic line starting from the Manyas Basin in the west and extending to the Yenişehir Basin in the east. Additionally, a second tectonic zone starting from Gemlik and passing through İznik is also active. Due to the active fault lines around the Marmara Region, the research area is located in the first-degree earthquake belt. The study area includes alluvial soils, brown forest soils, and brown forest soils without limestone. Agricultural activities are generally carried out on alluvial soils. In areas where the drainage is insufficient and the Kovanlık Stream passes through, thin alluvial soils are observed. Brown forest soils in the northern regions are largely used for agriculture and partially for settlement purposes. The brown forest soils without limestone, which have the widest distribution in the study area, are generally found in areas dominated by forest and maquis formations, providing a suitable environment for vegetation. Data obtained from Kestel, Yenişehir Airport, and İznik stations were used to determine the climatic characteristics of the study area. Based on these data, including average temperature, average low and high temperatures, relative humidity, average precipitation, and wind measurements, the climate diagram and precipitation regime type of the area were determined. An Arid Mediterranean Climate is observed in Kestel, while Yenişehir and İznik have a Semi-arid Mediterranean Climate. According to the climate diagram of Kestel, December is the wettest and coldest month, while August is the hottest and driest month. The annual temperature difference is 15°C, and the dry period lasts from July to October. The heaviest rainfall generally occurs in the winter months. According to the climate diagram of Yenişehir, January is both the wettest and coldest month, while August is both the hottest and driest month. The dry period lasts from May to October. According to the İznik climate diagram, January is the coldest month, with an average temperature of around 6 °C. August is the hottest month, with an average temperature of around 24.8 °C. The dry period extends from June to October, while the rainy period lasts from October to May. The study area is located on the southern slopes of Katırlı Mountain and to the east of the Yenişehir Plain, hosting various vegetation types such as meadows, maquis, and forests. Grassland areas are observed up to an elevation of 200 meters, while between 200 and 500 meters, maquis, shrublands, and small trees are found. Above 500 meters, forested areas are present. Tree species such as Pinus brutia Ten., Quercus sp., and Pinus sp. are commonly observed in forested areas. Additionally, alongside natural vegetation, agricultural areas cover a significant portion of the landscape. Green areas within the village and agricultural lands constitute an important part of the non-native vegetation in the region. In these studies, a total of 378 species and subspecies belonging to 229 genera and 69 families were identified in Gölcük Village and its surroundings. Among these taxa, three belong to the Pteridophyta division, and 375 belong to the Spermatophyta division. Within the Spermatophyta division, four taxa belong to the Gymnospermae subclass, and 371 belong to the Angiospermae subclass. Among the remaining plants from the Angiospermae subclass, 333 belong to the Dicotyledonae class, and 38 belong to the Monocotyledonae class. The top five families with the highest genus diversity in the study area are Asteraceae with 36 different genera (15.72%), Apiaceae with 15 different genera (6.55%), Brassicaceae with 14 different genera (6.11%), Fabaceae with 12 different genera (5.24%), and Lamiaceae with 11 different genera (4.80%). Additionally, Rosaceae and Poaceae each have 10 different genera (4.37%), Ranunculaceae and Liliaceae each have 8 different genera (3.49%), and Boraginaceae has 7 different genera (3.06%). The top five families in terms of species and subspecies richness identified in the study area are Asteraceae with 58 taxa (15.34%), Fabaceae with 33 taxa (8.73%), Rosaceae with 23 taxa (6.08%), Lamiaceae with 23 taxa (6.08%), and Brassicaceae with 17 taxa (4.50%). Similarly, Apiaceae and Ranunculaceae each have 17 taxa (4.50%), Liliaceae and Poaceae each have 13 taxa (3.44%), and Scrophulariaceae has 11 taxa (2.91%). The genera with the highest taxonomic richness in the study area are Trifolium with 8 taxa (2.12%), Medicago with 6 taxa (1.59%), and Ranunculus with 6 taxa (1.59%), followed by Rumex, Geranium, Vicia, and Quercus, each with 5 taxa (1.32%), and Alyssum, Malva, and Lathyrus, each with 4 taxa (1.06%). The distribution and proportions of taxa according to phytogeographic regions are as follows: 63 taxa (16.67%) belong to the Mediterranean element, 50 taxa (13.23%) belong to the Euro-Siberian element, 5 taxa (1.32%) belong to the Irano-Turanian element, and 260 taxa (68.78%) belong to poly-regional or undefined regions. The study area lies in a transitional zone between the Mediterranean and Euro-Siberian phytogeographic regions, allowing for a mixture of different plant species. Climatic and topographic diversity support the presence of various plant species in this region. Transitional zones, being rich in biological diversity, harbor plant species from both the Mediterranean and Euro-Siberian phytogeographic regions, as well as those belonging to the Irano-Turanian phytogeographic region. The connections between phytogeographic regions facilitate the spread of plant species from the Irano-Turanian Phytogeographic Region to these areas. These factors explain the presence of plant species belonging to the Irano-Turanian phytogeographic region in the study area. The classification of taxa based on life forms in the study area is as follows: Phanerophyte, 48 taxa (12.70%); Chamaephyte, 19 taxa (5.03%); Hemicryptophyte, 147 taxa (38.89%); Cryptophyte, 38 taxa (10.05%); Therophyte, 124 taxa (32.80%); and Vascular parasite, 2 taxa (0.53%). The number of endemic taxa is 4, with an endemism rate of 1.06% for the area. The endemism rate in our study area is considerably lower compared to the overall endemism rate in our country. Especially, the prevalence of hobby gardens in recent years, coupled with people's desire for nature and organic farming, leads to the destruction of natural vegetation for the purpose of agricultural land formation. This situation results in habitat destruction and, consequently, a decrease in endemic plant species.