تغييرات تنوع و تراكم جمعيت پرندگان آبزي و كنار آبزي در تالاب سد شيرين سو

Variation and Density of Populations of Aquatic and Wader Birds in Shirin Sou Dam

امروزه پرندگان آبزي و كنار آبزي از جنبه­هاي مختلف داراي ارزش بالايي بوده و در مطالعات به عنوان شاخص تنوع زيستي به‌شمار مي­روند. مطالعه حاضر با هدف بررسي روند تغيير و مقايسه شاخص‌هاي تنوع و تراكم پرندگان آبزي و كنار آبزي تالاب سد شيرين سو در استان همدان به مدت يك سال انجام گرفت. براي اين منظور پرندگان اين تالاب از مهر 1388 تا شهريور 1389 هر ماه سرشماري شدند. نتايج حاصل از بررسي­ها نشان داد كه بيشترين تراكم پرندگان در ماه آبان و برابر با 78/23 قطعه در هكتار بوده است. بيشترين و كمترين مقدار شاخص تنوع در ميان شاخص‌هاي به كار رفته براي شاخص سيمپسون به‌ترتيب با ارزش عددي 0/93 و 0/69 نشان داده شد. بيشترين مقدار شاخص يكنواختي نيز براي شاخص اسميت و ويلسون (0/8) و همچنين كمترين مقدار براي شاخص سيمپسون (0/27) و كامارگو (0/27) به‌دست آمدند. بيشينه و كمينه تراكم در دوره بررسي در تالاب سد شيرين سو به‌ترتيب به ماههاي آبان (23/78) و بهمن (1/17) اختصاص داشت. تعداد گونه‌هاي كنار آبزي در ماه‌هاي مختلف سال بيشتر از گونه­هاي آبزي بود در حالي­كه فراواني پرندگان آبزي همواره بيشتر از كنار آبزي بوده است. به‌نظر مي­رسد تالاب سد شيرين سو از نظر مهيا كردن منابع تغذيه­اي براي گونه­هاي آبزي قابليت بهتر و بيشتري داشته است و اين مسئله نيز با مشاهده فراواني بيشتر پرندگان آبزي نسبت به گونه­هاي كنار آبزي نمود پيدا كرده است.

Abstract Today, aquatic and aquatic fauna have high value in many aspects and are considered as indicators of biodiversity in studies. Therefore, the present study was conducted with the aim of studying the trend of changing and comparing the indices of diversity and density of aquatic and aquatic birds in the wetland of Shirin Sou dam in Hamadan province, it was an indicator for 1 year. For this purpose, the birds of this wetland were counted from October 2009 to September 2010. The results showed that the highest bird density in the month of November was 23.77 hectares. The highest and lowest values of Simpson's index in Shirin Su Dam lake were recorded in March (0.93) and March (0.69) respectively. Also, the highest and lowest values of Shannon diversity index were in October and October (4.40) and Bahman (2.5). For the beryllium diversity index, the highest and lowest values, as well as the Shannon diversity index, were shown in October (4/10) and Bahman (1.6). In terms of Simpson's uniformity index, the highest and the lowest uniformity were reported in Shirin Su Dam lagoon in February (0.7) and May (0.27). For the Camargo uniformity index, Simmons index was the highest and lowest in Bahman (0.68) and May (0.27). For the Smith Wilson uniformity index, the highest and lowest values were determined in February and March and were respectively 0.8 and 0.36 respectively. The maximum and minimum densities in the survey period in the wetland of Shirin Sou dam were allocated to the months of November (23.78) and Bahman (1.17), respectively. The number of aquatic species in different months of the year was more than aquatic species. But the abundance of aquatic birds has always been more than aquatic. The Shirin Su Dam Lake seems to be better and more capable of providing nutritional resources for aquatic species. an‎d this issue has also been found by observing the abundance of aquatic birds in relation to aquatic species.