Identification, Biomass determination and seasonal changes trend of the dominant aquatic plants’ cover in Anzali wetland

Abstract

Aquatic plants play an important role in the aquatic ecosystems because of food production and habitats for fish, wildlife, and other aquatic organisms. In recent years, many parameters such as high the mass of nutrition, organic matter and pollution have had a significant effect on the variation of the biological population. In this study, the samples of aquatic plants were identified in 4 stations of Anzali Wetland ( West, Center, Sheijan and Siah kishim) and dominant species biomass were investigated. In this study, 21 plant species belonging to 17 Family of aquatic plants were identified. So, 540 samples were collected in the plot of 1 m2 in 15 stations by systematic random sampling. Species were identified and wet weight was determined. The physic-chemical parameters of water were measured based on standard methods. The relationship between plant coverage (Flura) and Physico-chemical characteristics of water was analyzed by using of PCA in Canaco 4 software. According to this study, the Potamogenaceae and Thyphaceae specified the highest population in 4 and 2 genera, respectively. Based on Rainier’s method, the results of aquatic species classification showed that the highest percentage of plants such as Cryptophyte ( 37.2 %), trophite (23.53%) and Halophite ( 39.38 %) were the main structure of the plant diversity due to climatic features in Anzali wetland. As well as to evaluate the plant Chorotype, plant elements of this area were extracted and compared by using of available resources. The wetland Crorologic group listed by Cosmopolitan ( 57.14%), multi-region (28.57%) Europe-Siberian and Mediterranean ( 7.14%) & Iranian-Turanian (7.14%). The result showed that the average of the total biomass of aquatic plants was 746 g/m2 in this area. The result also showed Ceratophyllum demersum, Nelumbium capsicum and, Trapa natans had the most effect on increasing and decreasing weight of the plant's biomasses in different seasons. The analyses of PCA showed that highest biomass wet weight because of the potential Ceratophyllum demersum for growth in the depths of the wetlands and high nutrient loads in this area.