Root Biomass and Root Carbon and Nitrogen Stocks of Ash, Alder, and Oak Stands in Karacabey Floodplain Forest

Abstract

The main aim of this study was to investigate total root biomass and root carbon and nitrogen stocks of ash (Fraxinus angustifolia Vahl.), alder (Alnus glutinosa L.), and oak (Quercus cerris) stands in relation to the well-drained and poorly drained sites in Karacabey floodplain forests. Root samples were taken in autumn (October) using soil cores method and sorted into fine (0–2 mm), medium (2–5 mm), and coarse (5–10 mm) root diameter classes. The results showed that ash and oak stands had higher total root biomass in the poorly drained site (3865 kg ha?1 and 1949 kg ha?1, respectively) than in the well-drained site (1569 kg ha?1 and 1301 kg ha?1, respectively), whereas alder stands showed the opposite trend with having lower total root biomass in the poorly drained site (1878 kg ha?1) than in the well-drained site (2227 kg ha?1). In general, ash and oak stands had higher root carbon stocks in the poorly drained site than in the well-drained site, whereas alder stands had lower root carbon stocks in the poorly drained site than in the well-drained site. However, for all three tree species root nitrogen stocks were higher in the poorly drained site than in the well-drained site. It is concluded that the differences in stand characteristics, stand ages, tree species, soil properties, and microclimate conditions could be responsible for those variations. Thus, more extensive and detailed root biomass studies are in need to investigate the responses of tree species under different climatic, edaphic, and stand characteristics in flood plain forests of Turkey.