Anadolu'daki Başlıca Karasal Biyomlarda İklim Değişikliği , Yangın ve Otlatmanın Vejetasyon Dinamikleri Üzerine Etkisinin Modellenmesi

Abstract

In this thesis, long-term vegetation dynamics in three different terrestrial biomes of Anatolia (Central Anatolian Steppe, Mediterranean forests and shrublands, and Karadeniz temperate mixed forests) were examined using the FATELAND model. The aim of the research was to investigate the effects of different climate change scenarios and disturbance regimes (grazing and fire) on the vegetation structure and plant functional groups in these biomes. In this context, plant functional groups specific to each biome were defined using the functional trait approach for each biome. In the Central Anatolian steppe biome, 50-year dynamics of vegetation structure and functional groups under grazing regimes of different intensities were simulated. In the Mediterranean shrubland and forest biome, the long-term effects over 120 years of different climate change and fire frequency scenarios were investigated. In the Black Sea temperate mixed forest biomes, the effects of current mixed forest dynamics and crown fires on vegetation dynamics were analyzed through 120-year simulations. In the Central Anatolian steppe biome, it was determined that moderate-intensity grazing preserves the stability of vegetation and functional diversity, while overgrazing and the absence of grazing lead to long-term state changes in vegetation. Overgrazing caused the loss of spiny and non-spiny subshrubs and perennial forbs; perennial graminae and annuals became dominant. In the Mediterranean shrubland and forest biome, under pessimistic climate change scenarios, it was found that the competitive dynamics between the Quercus and Pinus functional groups shifted in favor of Pinus. It was observed that functional groups like Erica and Cistus, which have high post-fire recovery ability, increased their abundance under increasing drought conditions. In the Black Sea temperate mixed forest biomes, after crown fires, it was observed that broadleaf trees showed rapid recovery and became dominant, while the abundance of coniferous trees decreased. The study focused on the effects of different climate change scenarios and disturbance regimes on the vegetation dynamics in Anatolia’s terrestrial biomes using vegetation moedelling approach. The findings provide important information for the development of ecosystem management and conservation strategies. In particular, important questions were asked and answers were found to understand the potential effects of climate change and ecological disturbances on vegetation and to develop strategies to mitigate these effects.