بررﺳﻲ ﭘﺮاﻛﻨﺶ و ﺗﺮاﻛﻢ ﮔﻴﺎﻫﺎن آﺑﺰي ﻏﺎﻟﺐ در ﺑﺨﺶ ﻏﺮﺑﻲ ﺗﺎﻻب اﻧﺰﻟﻲ

Investigation of distribution and abundance of aquatic plants dominant in the western part of Anzali Wetland

ﮔﻴﺎﻫﺎن آﺑﺰي در ﻣﺤﻴﻂﻫﺎﻳﻲ ﻛﻪ ﻣﻮاد ﻣﻐﺬي اﻓﺰاﻳﺶ ﻳﺎﻓﺘﻪاﻧﺪ ﺑﻪ ﺷﺪت رﺷﺪ ﻛﺮده و در ﺑﺴﻴﺎري ﻣﻮارد ﺑﻪ ﺻﻮرت ﻣﻌﻀﻞ ﺧﻮدﻧﻤﺎﻳﻲ ﻣﻲﻛﻨﻨﺪ. ﺗﺎﻻب اﻧﺰﻟﻲ ﺗﺤﺖ ﺗﺄﺛﻴﺮ رﺷﺪ ﺳﺮﻳﻊ ﮔﻴﺎﻫﺎن آﺑﺰي ﻗﺮارﮔﺮﻓﺘﻪ اﺳﺖ. در اﻳﻦ ﻣﻄﺎﻟﻌﻪ ﺷﻨﺎﺳﺎﻳﻲ و ﺗﻌﻴﻴﻦ زيﺗﻮده ﮔﻴﺎﻫﺎن آﺑﺰي ﻏﺎﻟﺐ در ﺑﺨﺶ ﻏﺮﺑﻲ ﺗﺎﻻب اﻧﺰﻟﻲ اﻧﺠﺎم ﮔﺮﻓﺖ. ﻧﺘﺎﻳﺞ ﻧﺸﺎن داد ﻛﻪ از ﭼﻬﺎر ﮔﻮﻧﻪ ﮔﻴﺎه ﻏﻮﻃﻪور ﺷﻨﺎﺳﺎﻳﻲ ﺷﺪه Ceratophyllum demersum و Myriophyllum spicatum در اﻛﺜﺮ ﻣﻨﺎﻃﻖ از ﭘﺮاﻛﻨﺶ و ﺗﺮاﻛﻢ ﺑﺎﻻﻳﻲ ﺑﺮﺧﻮردار ﺑﻮدﻧﺪ. ﻣﻴﺎﻧﮕﻴﻦ زيﺗﻮده در ﺗﺎﺑﺴﺘﺎن در ﺣﺪ 536/5 ± 743/8 و در زﻣﺴﺘﺎن در ﺣﺪ 311 ± 292 ﮔﺮم در ﻣﺘﺮﻣﺮﺑﻊ وزن ﺧﺸﻚ ﺑﻮده ﻛﻪ ﺗﻔﺎوت آﻧﻬﺎ در اﺑﺘﺪاي ﺑﺨﺶ ﻏﺮﺑﻲ ﺑﺴﻴﺎر ﺑﻴﺸﺘﺮ از ﻣﻨﺘﻬﻲ اﻟﻴﻪ آن ﺑﻮد. در ﺗﺎﺑﺴﺘﺎن Azolla filiculoides از ﺗﺮاﻛﻢ ﺑﺎﻻﻳﻲ در ﻣﻨﺎﻃﻖ ﺣﺎﺷﻴﻪاي ﺗﺎﻻب ﺑﺮﺧﻮردار ﺑﻮد وﻟﻲ در زﻣﺴﺘﺎن در ﻫﻴﭽﻴﻚ از ﻣﻨﺎﻃﻖ ﻣﻮرد ﺑﺮرﺳﻲ رؤﻳﺖ ﻧﺸﺪ. دو ﮔﻮﻧﻪ Nelumbo nucifera و Hydrocotyle vulgaris از ﮔﻴﺎﻫﺎن ﺑﺮگ ﺷﻨﺎور ﻏﺎﻟﺐ ﺑﻪوﻳﮋه در ﻧﻮاﺣﻲ ﺣﺎﺷﻴﻪاي ﺑﻮده ﻛﻪ در ﻣﻨﺎﻃﻖ ﭘﺮاﻛﻨﺶ، زيﺗﻮدهاي ﻣﻌﺎدل 70/4 ± 240/6 و /142 ± 338/8 ﮔﺮم در ﻣﺘﺮﻣﺮﺑﻊ وزن ﺧﺸﻚ داﺷﺘﻨﺪ. ﻣﻘﺪار ﺷﺎﺧﺺ ﻣﺎﻛﺮوﻓﻴﺘﻲ ﺗﺎﻻب )WMI( در ﺗﻤﺎم ﺑﺨﺶﻫﺎي ﺗﺎﻻب در ﺣﺪ 1 ﺑﻮد. ﺳﺎﻻﻧﻪ ﺑﺎ ﻣﺮگ ﮔﻴﺎﻫﺎن ﻣﻘﺪار ﺑﺎﻻﻳﻲ از ﻣﻮاد آﻟﻲ وارد اﻛﻮﺳﻴﺴﺘﻢ ﺗﺎﻻب اﻧﺰﻟﻲ ﻣﻲﮔﺮدد ﻛﻪ ﻳﻮﺗﺮوفﺗﺮ ﺷﺪن ﺑﻴﺸﺘﺮ ﺗﺎﻻب را در ﭘﻲ ﺧﻮاﻫﺪ داﺷﺖ. ﻟﺰوم ﺑﺮداﺷﺖ ﮔﻴﺎﻫﺎن آﺑﺰي ﺑﺮاي ﺣﻔﻆ و اﺣﻴﺎء ارزشﻫﺎي اﻛﻮﻟﻮژﻳﻚ و اﻗﺘﺼﺎدي ﺗﺎﻻب اﻧﺰﻟﻲ ﺑﻴﺶ از ﭘﻴﺶ اﺣﺴﺎس ﻣﻲﮔﺮدد.

Aquatic plants are severely increased in eutrophic ecosystem and sometime be caused problem as different aspects. The high abundance of aquatic plants and sedimentation are the main problems in Anzali Wetland. In this study the identification and biomass of dominated aquatic plants was investigated in western part of Anzali Wetland. Among four submerged macrophytes, the Ceratophyllum demersum and Myriophyllum spicatum had the highest distribution and abundance. The biomass average were 743.8 ± 536.5 and 292 ± 311 gr dry weight m-2 in summer 2017 and winter 2018, respectively. The biomass seasonal change was more in eastern rather than western of studied area. Azolla filiculoides had a high abundant and distributed in marginal area during summer while it was completely and incredibly disappeared until winter around Anzali Wetland. Among marginal floating macrophytes, Nelumbo nucifera and Hydrocotyle vulgaris were highly distributed with 240.6 ± 70.4 and 338.8 ± 142 gr dry weight m-2 respectively. The Wetland Macropphyte Index value was nearly similar around study area and was about 1. The annually dead of macrophytes in winter can increase the eutrophication trend in Anzali Wetland. Then, it's necessary to remove the aquatic plants in Anzali Wetland to preserve of its ecological and economical values.