مقايسه شاخص هاي تنوع و يكنواختي گونه اي در شدت هاي مختلف چراي دام در مراتع دامنه هاي جنوب شرقي سبلان

Comparison of Plant Species Diversity and Evenness in Different Grazing Levels Southeastern Slopes of Sabalan

زﻣﯿﻨﻪ و ﻫﺪف : ارزﯾﺎﺑﯽ ﺗﻨﻮع و ﯾﮑﻨﻮاﺧﺘﯽ ﮔﻮﻧﻪ اي ﺑﻪ درك ﺻﺤﯿﺢِ ﮐﺎرﮐﺮد اﮐﻮﺳﯿﺴﺘﻢ، ﺣﻔﻆ و ﻧﮕﻬﺪاري ذﺧﺎﯾﺮ ژﻧﯽ، ﺑﺮرﺳﯽ و ﮐﻨﺘﺮل ﺗﻐﯿﯿﺮات ﻣﺤﯿﻄﯽ، و ﻣﻮﻓﻘﯿﺖ ﯾﺎ ﻋﺪم ﻣﻮﻓﻘﯿﺖ ﺑﺮﻧﺎﻣﻪ ﻫﺎي ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ ﮐﻤﮏ ﻣﯽ ﮐﻨﺪ. ﭼﺮاي ﺑﯽ روﯾﻪ و ﺑﺪون ﺑﺮﻧﺎﻣﻪ ي دام ﯾﮑﯽ از ﺷﺎﯾﻊ ﺗﺮﯾﻦ و ﺷﺎﯾﺪ ﻣﻬﻢ ﺗﺮﯾﻦ ﻋﺎﻣﻞ ﺗﺨﺮﯾﺐ ﻣﺮاﺗﻊ و ﮐﺎﻫﺶ ﺗﻨﻮع و ﯾﮑﻨﻮاﺧﺘﯽ ﮔﻮﻧﻪ اي اﺳﺖ. روش ﺑﺮرﺳﯽ : ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ اﺛﺮ ﺷﺪت ﻫﺎي ﻣﺨﺘﻠﻒ ﭼﺮاﯾﯽ ﺑﺮ ﺗﻨﻮع و ﯾﮑﻨﻮاﺧﺘﯽ ﮔﻮﻧﻪ اي در ﻣﺮاﺗﻊ داﻣﻨﻪ ﻫﺎي ﺟﻨﻮب ﺷﺮﻗﯽ ﺳﺒﻼن، ﺳﻪ روﯾﺸﮕﺎه داراي ﻣﺪﯾﺮﯾﺖ ﻫﺎﯾﯽ ﭼﺮاﯾﯽ ﻣﺘﻔﺎوت ﺷﺎﻣﻞ ﭼﺮاي ﺳﺒﮏ، ﻣﺘﻮﺳﻂ و ﺷﺪﯾﺪ اﻧﺘﺨﺎب و ﺑﺎ اﺳﺘﻔﺎده از ﭘﻼت ﻫﺎي ﯾﮏ ﻣﺘﺮ ﻣﺮﺑﻌﯽ در ﻃﻮل ﺳﻪ ﺗﺮاﻧﺴﮑﺖ 200ﻣﺘﺮي اﻗﺪام ﺑﻪ ﻧﻤﻮﻧﻪ ﺑﺮداري از ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ ﺷﺪ. در ﻫﺮ ﭘﻼت، ﻓﻬﺮﺳﺖ ﮔﻮﻧﻪ ﻫﺎي ﻣﻮﺟﻮد، درﺻﺪ ﺗﺎج ﭘﻮﺷﺶ و ﺗﻌﺪاد اﻓﺮاد ﻫﺮ ﮔﻮﻧﻪ ﯾﺎدداﺷﺖ ﺷﺪ. ﺷﺎﺧﺺ ﻫﺎي ﺗﻨﻮع ﺳﯿﻤﭙﺴﻮن، ﺷﺎﻧﻮن و ﺑﺮﯾﻠﺌﻮن و ﺷﺎﺧﺺ ﯾﮑﻨﻮاﺧﺘﯽ ﮐﺎﻣﺎرﮔﻮ، ﺳﯿﻤﭙﺴﻮن و اﺳﻤﯿﺖ- وﯾﻠﺴﻮن ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺗﺄﺛﯿﺮ ﻣﻌﻨﯽ دار ﺷﺪت ﭼﺮا ﺑﺮ ﺷﺎﺧﺺ ﻫﺎي ﺗﻨﻮع و ﻏﻨﺎ ﻻزم اﺳﺖ ﻣﺪﯾﺮان ﺑﺨﺶ ﻣﺮﺗﻊ ﺑﺎ ﮐﻨﺘﺮل ﺷﺪت ﭼﺮا از ﻃﺮﯾﻖ ﺷﯿﻮه ﻫﺎي ﻣﺪﯾﺮﯾﺘﯽ در ﺟﻬﺖ ﺣﻔﻆ ﺗﻨﻮع ﻣﻮﺟﻮد در اﮐﻮﺳﯿﺴﺘﻢ ﻫﺎي ﻣﺮﺗﻌﯽ ﻋﻤﻞ ﮐﻨﻨﺪ. ﺑﻨﺎﺑﺮاﯾﻦ ﮐﺎﻓﯽ اﺳﺖ ﮐﻪ ﺑﻬﺮه ﺑﺮداري ﺑﺮ ﻣﺒﻨﺎي ﭼﺮاي ﻣﺘﻮﺳﻂ را ﻫﺪف ﻣﺪﯾﺮﯾﺖ ﻗﺮار داد و ﻣﻨﺎﻃﻖ ﺑﺎ ﭼﺮاي ﺷﺪﯾﺪ را ﺑﻪ ﺷﺮاﯾﻂ ﭼﺮاي ﻣﺘﻮﺳﻂ رﺳﺎﻧﺪ ﺗﺎ ﺑﻪ ﺗﺪرﯾﺞ ﮔﻮﻧﻪ ﻫﺎي ﻣﺮﻏﻮب و ﺧﻮش ﺧﻮراك ﺟﺎﯾﮕﺰﯾﻦ ﮔﻮﻧﻪ ﻫﺎي ﺧﺸﺒﯽ و ﻧﺎﻣﺮﻏﻮب ﺷﻮﻧﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ : ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﻨﻄﻘﻪ ﺑﺎ ﺷﺪت ﭼﺮاي ﻣﺘﻮﺳﻂ ﺗﺎ ﺳﺒﮏ ﺑﯿﺶ ﺗﺮﯾﻦ ﻣﯿﺰان ﺗﻨﻮع و ﯾﮑﻨﻮاﺧﺘﯽ را ﻧﺴﺒﺖ ﺑﻪ ﻣﻨﻄﻘﻪ ﺑﺎ ﺷﺪت ﭼﺮاي ﺳﻨﮕﯿﻦ دارد. ﮐﻪ ﻧﺸﺎن ﮔﺮ ﺷﺮاﯾﻂ ﻣﺴﺎﻋﺪ ﺑﺮاي اﺳﺘﻘﺮار ﮔﻮﻧﻪ ﻫﺎي ﻣﺘﻌﺪد اﺳﺖ.

Background and Objective: Assess the diversity of the understanding of ecosystem function; maintain genetic resources, checking environmental changes, and success or failure will help natural resource management programs. Over-grazing and uncontrolled usage of rangelands are the most common and the most important factor of rangeland degradation which causes a reduction in species diversity. Method: In order to investigate the effect of different grazing intensities on species diversity and uniformity in the rangelands of the southeastern slopes of Sabalan, three habitats with different grazing managements including light, medium and severe grazing were selected and one square meter plots along three 200-meter transects were sampled. In each plot, the list of available species, canopy percentage and number of individuals of each plot were recorded. Simpson, Shannon and Brillon diversity indices and Camargo, Simpson and Smith-Wilson uniformity indices were calculated. Findings: The results showed that the area with medium to light grazing intensity has the highest diversity and uniformity compared to the area with heavy grazing intensity which indicates favorable conditions for the establishment of several species. Discussion and Conclusions: Due to the significant effect of grazing intensity on diversity and richness indices, it is necessary for rangeland managers to control grazing intensity through management methods to maintain the diversity of rangeland ecosystems. Therefore, it is enough to target the management based on moderate grazing and bring the areas with intense grazing to the conditions of moderate grazing so that the good and tasty species gradually replace the woody and poor species. Desirable species and plant species and woody species are poor.