Ecological stoichiometry and strategies of plants belonging different habitats in Kızılırmak Delta

Abstract

Kızılırmak Delta (Samsun, Türkiye) comprises a fine-scale mosaic of wetlands and saline/halophytic habitats, where strong environmental gradients may influence plant nutrient-use patterns and ecological strategies. Here, we evaluated how leaf stoichiometry (N, P, N:P) and CSR-based strategies vary across contrasting habitats and how these traits relate to measured soil and water chemistry. The dataset comprised 39 observations from nine terrestrial plant taxa sampled in three wetland localities (Balık, Cernek, and Liman lakes) and one saline area dominated by halophytes. Habitat differences were tested using Welch’s t tests; trait–environment relationships were assessed using correlations and redundancy analysis (RDA). Halophyte sites exhibited markedly higher salinity indicators (EC, TDS) and higher soil phosphorus (P) levels. In contrast, wetlands had higher soil pH and higher inorganic N forms (NH₄ and NO₂+NO₃) and total soil N. Leaf N was significantly higher in wetlands. In contrast, leaf P and community-level N:P did not differ significantly between habitats, despite significant differences in soil P. Leaf N declined with increasing TDS and soil P. RDA separated habitats along a salinity–nutrient gradient, with environmental predictors explaining ~19% of the variance in stoichiometric responses. Competitive categories across taxa dominated CSR assignments. Overall, the results indicate that salinity and nutrient form/availability jointly structure habitat differences in plant stoichiometry in Kızılırmak Delta, with nitrogen showing the strongest habitat signal.

Keywords

• nutrient limitation
• functional traits
• habitat filtering
• salinity stress
• coastal wetland

Kızılırmak Deltası'nda farklı habitatlara ait bitkilerin ekolojik stokiyometrisi ve stratejileri

Abstract

Kızılırmak Deltası (Samsun, Türkiye), sulak alanlar ile tuzlu/halofit habitatların iç içe geçtiği ve güçlü çevresel gradyanların görüldüğü bir mozaik sistemdir. Bu çalışmada, farklı habitatlarda yaprak stokiyometrisinin (N, P, N:P) ve CSR temelli stratejilerin nasıl değiştiği ve bu biyolojik örüntülerin toprak/su kimyasıyla nasıl ilişkili olduğu incelenmiştir. Veri seti, üç sulak alan lokalitesi (Balık, Cernek ve Liman gölleri) ile halofitlerin baskın olduğu bir tuzlu alandan örneklenen dokuz karasal bitki taksonuna ait toplam 39 gözlemi içermektedir. Habitat farkları Welch t testi ile değerlendirilmiş; özellik–çevre ilişkileri korelasyonlar ve redundans analizi (RDA) ile özetlenmiştir. Halofit habitatında EC ve TDS değerleri ile toprak P daha yüksek bulunurken; sulak alanlarda toprak pH’ı, inorganik N formları (NH₄ ve NO₂+NO₃) ve toplam toprak N daha yüksektir. Yaprak N sulak alanlarda anlamlı biçimde daha yüksekken, yaprak P ve topluluk düzeyinde N:P habitatlar arasında anlamlı farklılık göstermemiştir; bu durum, toprak P’daki büyük farklılıklara rağmen yaprak P’nin daha güçlü fizyolojik düzenleme/uyum mekanizmalarıyla kontrol edilebileceğine işaret etmektedir. Yaprak N, artan TDS ve toprak P ile azalma eğilimi göstermiş; RDA, örnekleri tuzluluk–besin gradyanı boyunca ayırmış ve çevresel değişkenler stokiyometrik varyansın yaklaşık %19’unu açıklamıştır. Sonuçlar, deltada özellikle azotun habitat farklılaşmasına en duyarlı stokiyometrik bileşen olduğunu göstermektedir.

Keywords

• besin elementi sınırlılığı
• işlevsel özellikler
• habitat süzgeci
• tuzluluk stresi
• kıyı sulak alanı

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