Effects of Soil and Vegetation Characteristics on Nematode Biodiversity and Community Structure in Forest Ecosystems of Adana Province, Türkiye

Abstract

This study was conducted to investigate the relationships between nematode biodiversity and soil and vegetation characteristics in forest ecosystems located in six sub-regions with different topographic and edaphic properties in Adana Province, Türkiye. Soil samples were collected from 0–30 cm and 30–60 cm depths in Sarıçam, Çukurova, Salbaş, Varda, Bürücek and Pozantı sub-regions. Nematodes were extracted, identified at the genus level and classified into trophic groups. Soil physical and chemical properties including pH, organic matter, texture, lime content and nutrient status were analyzed to evaluate their relationships with nematode community structure. The results revealed significant differences among sub-regions in terms of nematode abundance, diversity and trophic composition. Bacterivorous nematodes represented the dominant trophic group, while predatory and omnivorous nematodes showed relatively lower diversity. All soils exhibited alkaline characteristics, and soil organic matter and texture were identified as the main factors influencing nematode communities. Higher nematode abundance and diversity were observed in soils rich in organic matter and with loamy texture, whereas sandy soils with low organic matter content supported less diverse communities. Nematode abundance was generally higher in the upper soil layer (0–30 cm) than in deeper soil layers. The findings demonstrate that nematode biodiversity is strongly associated with edaphic factors, particularly soil organic matter and texture, and confirm the usefulness of nematodes as reliable bioindicators for assessing soil ecosystem condition in forest environments.