The Piosphere Effects of Livestock Grazing on Rangeland Vegetation in Ahir Mountain of Kahramanmaras Region

Kahramanmaraş Yöresi Ahır Dağı Meralarında Piospher’in Vejetasyon Yapısı Üzerindeki Etkileri

Özet

Mera vejetasyonları üzerinde oluşan aşırı otlatma baskısı, vejetasyonun bitki ile kaplı alan değerinin azalmasına ve botanik kompozisyonun değişmesine neden olmaktadır. Yapılan bu araştırmada Türkiye'nin Akdeniz bölgesinde yer alan, doğal su kaynaklarından biri olan Karagöl gölüne olan mesafeye göre piosferin vejetasyon üzerindeki etkileri incelenmiştir. Bunun için çalışma alanında yer alan doğal su kaynaklarından biri olan Karagöl gölünün piosfer etkisi araştırılmıştır. Vejetasyonda meydana gelen değişiklikler Karagöl gölü çevresinden 0-1000 m, 1000-3000 m ve 3000-5000 m uzaklıkta seçilen üç deneme alanı alınarak belirlenmiştir. Araştırma alanında ortalama bitki ile kaplı alan değerleri sırasıyla % 10.71, % 14.46 ve % 22.16 olarak belirlenmiştir. Göl çevresinde ortalama fırın kurusu ot1. IntroductionRangelands are a type of land on which the natural vegetation is dominated by grasses, forbs and shrubs and the land is managed as a natural ecosystem (SRM 2015). Rangeland areas play important role in terms of both biological diversity and grazing, due to having wide range of plant species. In addition, rangeland vegetation is important in preventing erosion and runoff (Gökkuş & Koç 2001).The total area of rangelands occupies 3.5 billion ha in world (FAO 2008). In Turkey, the area of rangelands is about 14.6 million hectares, while it was 50 million hectares in 1923 (TSI 2011). Within the same period, the number of animals grazing on rangelands increased from 20.3 million to 29.9 million cattle units (TSI 2011). Thus, rangelands continually decreased while the number of grazing animals per unit area increased, which led to everincreasing grazing pressure on rangelands. The vegetation structures of rangelands were deteriorated and productivity decreased due to increasing grazing pressure. Grazing pressure also reduced the density of vegetation coverage and emerged active surface erosion. Due to excessive, non-uniform, and untimely (i.e. while plants are not mature enough for grazing and soil is humid) grazing, deterioration process of vegetation has been accelerated in last decades.Unplanned grazing practices in Turkey resulted in non-uniform grazing which led to much greater grazing pressure in rangeland areas, especially rangeland sites located around water sources. Grazing animals on rangelands tend to stay around water sources because these animals are continuously in need of drinking water (Stoddart et al 1975). Grazing density around water sources decreases circumferentially away from the center verimi sırasıyla 63.90 kg da-1, 154.29 kg da-1 ve 214.63 kg da-1 olarak tespit edilmiştir. Vejetasyonun benzerlik indeksi değerlerine göre göl çevresinden uzaklaştıkça vejetasyonun farklılaştığı belirlenmiştir. En düşük benzerlik oranının birinci ve üçüncü deneme alanları arasında olduğu tespit edilmiştir

Abstract

Excessive grazing pressure on rangeland vegetation reduces the basal area value of vegetation and also changes the botanic composition. This study examined the piosphere effects of livestock grazing on rangeland vegetation based on distance from a natural water source. The piosphere effects were evaluated around Karagöl Lake, which is a natural water-source in Mediterranean region of Turkey. The changes in vegetation were determined within three different sites where sample plots were located at 0-1000 m, 1000-3000 m and 3000-5000 m away from the lake. The mean values of basal area in the study area were 10.71%, 14.46%, and 22.16% for three sites, respectively. The average oven-dry hay yield was 639.0 kg ha-1, 1542.9 kg ha-1, and 2146.3 kg ha-1, respectively. The vegetation similarity indices of the sites indicated that the botanic composition changed with respect to increasing distance from the lake. The lowest similarity index was encountered between the site one and site three (30.31%)