In this study, the AQUATIC and semi AQUATIC plants of Khuzestan province were studied during 2009-2010. In the studied area 50 species belonging to 32 genera and 24 families were identified.Ceratophyllum demersum, Najas marina and Potamogeton crispuswere the most dominant submerged species that constituted vast populations in the waters of this area.Typha laxmanni, Polygonum cespitosum, Phragmites australisand Cyperus pygmaeus made huge populations in the margins of the area. Potamogetonaceae, Polygonaceae and Juncaceae were the largest families, respectively. In Dezful, genera of Potamogeton were the largest genus of sub-merged plants in this area. In Shush – Ahvaz, genera ofPolygonum hydropiperwas the largest genus of marginal plants in this area.In Ahvaz, genera ofPhragmites australis were the largest genus of emersed plants in this area. In Shadegan wetland, genera of Phragmites australis, Cyperus pygmaeus, Scripus lariaceae and Juncuswere the largest genus in this area. Chorologically, 24% of species were Iran-Turanin. The largest of biotic spectrum of this area consisted of Hydrophyte (13%).

Background and Aim: Heavy metals are harmful to human health. AQUATIC plants can store large amounts of these heavy metals, and play an important role in the purification of these pollutants in AQUATIC ECOSYSTEMS. The aim of this study was to identify the AQUATIC plant species that absorb and purify heavy metals in the AQUATIC ECOSYSTEMS of Anzali wetland, north of Iran. Methods: Sampling of AQUATIC plants and sediments of Anzali wetland, north of Iran, was done randomly based on vegetation density in 10 stations in July 2019. Species were identified and registered. Then leaf, stem and root limbs were isolated and then digested samples were prepared. Atomic absorption spectrometry was used to analyze the heavy metals in these samples. Results: Among the plant families studied in Anzali Wetland, families of AQUATIC plants such as Poaceae or Gramineae, Cyperaceae, Potamogetonaceae, Hydrocharitaceae, Lemnaceae, Labiatae had the highest number of species in the absorption of heavy metals. Species that used the three parts of root, stem and leaf simultaneously to absorb heavy metals was the highest frequency of 96%, species that used only roots had 22%, roots and leaves had 69%, and roots and buds had 3%. Among the metals absorbed by different plant species, zinc with 13. 97%, lead with 13. 44%, and cadmium with 12. 9% had a high frequency and metals such as copper, nickel and iron were in the next category. Conclusion: In the present study, the genus Poaceae had the highest abundance of species and the roots had a greater share than the stem and leaves as the organ that absorbs heavy metals. Among heavy metals, zinc had the highest frequency of uptake by AQUATIC plants.

Periphytons are the most important microorganism communities which can be found almost in all AQUATIC systems. Periphytons play important roles in ecological functions of an ecosystem. They are composed of multilayered consortia of photoautotrophs (e. g. unicellular and filamentous cyanobacteria, benthic diatoms and green microalgae) and heterotrophs (bacteria, fungi and protozoa). Due to the role of periphytons in the processes of nitrogen fixation and dissolution of insoluble phosphorus and potassium, Samples of sediment, water and periphytons collected and investigated from three lagoons in Fashtam, Tazesel and Qalewersel in Gillan province. Results showed that Chlorophyta, Bacillariophyta and Cyanobacteria constituted 26. 24%, 56. 06% and 17. 69% of the periphyton components in Qalewersel lagoon, respectively. In the Fashtam lagoon, the Chlorophyta, Charophyta, Euglenozoa, Ochrophyta, Bacillariophyta, and cyanobacteria species formed 38. 48%, 20. 58%, 1. 72%, 1. 74%, 19. 68% and 19. 52% of the periphyton components, respectively. Also, in the Tazesel lagoon, Chlorophyta, Euglenozoa, Bacillariophyta and Cyanobacteria constituted about 13. 93%, 0. 56%, 51. 9% and 33. 6% of components of periphyton, respectively.

AQUATIC plants as a ring of food chain due to absorbtion of heavy metals can be indicator of the relatively increasing of this elements in the water or sediments of any AQUATIC ECOSYSTEMS. First AQUATIC plants were collected from the north ponds of Iran and after indentificution, mechanism, organs and types of absorbed elementes were determined by broadly library investigation from the lation sources Ultimately, the data were analyzed by Excel software. The results indicated that plant species showed different abilities in the absorption of elements so that Poaceae family had high species frequency and the root had more share as an absorbent organ to stem and leaf. Also Zn with 13.9% had the highest absorption frequency among other elements and Phytoextraction was the major absorption mechanism.