بررسي تأثير شدت چراي دام بر برخي مشخصه هاي پوشش گياهي و فيزيكوشيميايي خاك (مطالعه موردي: مراتع سامان روستاي كلش، استان اردبيل)

Effect of grazing intensity on vegetation and soil physio-chemical properties (Case study: in rangelands of Kolash village, ParsAbad, Ardabil province)

ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ اﺛﺮ ﮔﺮادﯾﺎن ﭼﺮا در ﻣﯿﺰان ﺗﺨﺮﯾﺐ ﻣﺮﺗﻊ، اﺛﺮ ﺳﻪ ﺷﺪت ﭼﺮاﯾﯽ (ﺳﺒﮏ، ﻣﺘﻮﺳﻂ و ﺳﻨﮕﯿﻦ) ﺑﺮ وﯾﮋﮔﯽ ﻫﺎي ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ و ﻓﯿﺰﯾﮑﻮﺷﯿﻤﯿﺎﯾﯽ ﺧﺎك در ﻣﺮاﺗﻊ روﺳﺘﺎي ﮐﻠﺶ ﺷﻬﺮﺳﺘﺎن ﭘﺎرس آﺑﺎد در اﺳﺘﺎن اردﺑﯿﻞ ارزﯾﺎﺑﯽ ﺷﺪ. در ﻫﺮ ﺷﺪت ﭼﺮاﯾﯽ، ﺳﻪ ﺗﺮاﻧﺴﮑﺖ 90 ﻣﺘﺮي، و در ﻫﺮ ﺗﺮاﻧﺴﮑﺖ 10 ﭘﻼت ﯾﮏ ﻣﺘﺮﻣﺮﺑﻌﯽ ﺑﺮداﺷﺖ ﺷﺪ. در ﻫﺮ ﭘﻼت ﺑﺎ ﺛﺒﺖ وﯾﮋﮔﯽ ﻫﺎي ﺗﮏ ﺗﮏ ﮔﻮﻧﻪ ﻫﺎ، ﺗﺮﮐﯿﺐ، ﺗﺮاﮐﻢ و درﺻﺪ ﺗﺎج ﭘﻮﺷﺶ ﮔﻮﻧﻪ ﻫﺎ و ﮐﻞ و ﻫﻤﭽﻨﯿﻦ ﻻﺷﺒﺮگ، ﺧﺎك ﻟﺨﺖ و ﺳﻨﮓ و ﺳﻨﮕﺮﯾﺰه ﺛﺒﺖ ﺷﺪ. ﻧﻤﻮﻧﻪ ﺑﺮداري ﺧﺎك از ﻋﻤﻖ 0 ﺗﺎ 30 ﺳﺎﻧﺘﯽ ﻣﺘﺮي، در ﭘﻼت ﻫﺎي اول، ﭘﻨﺠﻢ و دﻫﻢ ﻫﺮ ﺗﺮاﻧﺴﮑﺖ ﺑﺮداﺷﺖ و ﺑﻪ ﻋﻨﻮان ﯾﮏ ﻧﻤﻮﻧﻪ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪ. اﻧﺪازه ﮔﯿﺮي وﯾﮋﮔﯽ ﻫﺎي ﺧﺎك ﺷﺎﻣﻞ اﺳﯿﺪﯾﺘﻪ، ﻫﺪاﯾﺖ اﻟﮑﺘﺮﯾﮑﯽ، ﻣﻨﯿﺰﯾﻢ، ﮐﻠﺴﯿﻢ، ﭘﺘﺎﺳﯿﻢ، آﻫﮏ، ﻓﺴﻔﺮ، ﻣﺎده آﻟﯽ، ﻣﯿﺎﻧﮕﯿﻦ ﻗﻄﺮ وزﻧﯽ ﺧﺎﮐﺪاﻧﻪ ﻫﺎ و درﺻﺪ ذرات ﺷﻦ، ﺳﯿﻠﺖ و رس اﻧﺠﺎم ﺷﺪ. ﺑﺮاي ﺑﺮرﺳﯽ اﺛﺮ ﺷﺪت ﭼﺮا ﺑﺮ ﮐﻠﯿﻪ وﯾﮋﮔﯽ ﻫﺎي اﻧﺪازه ﮔﯿﺮي ﺷﺪه از آزﻣﻮن ﺗﺠﺰﯾﻪ وارﯾﺎﻧﺲ و از آزﻣﻮن داﻧﮑﻦ ﺑﺮاي ﻣﻘﺎﯾﺴﻪ ﻣﯿﺎﻧﮕﯿﻦﻫﺎ و ﮔﺮوهﺑﻨﺪي آﻧﻬﺎ اﺳﺘﻔﺎده ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﺎ اﻓﺰاﯾﺶ ﺷﺪت ﭼﺮا، درﺻﺪ ﺗﻮﻟﯿﺪ (0/05>P) و ﺗﺮاﮐﻢ (0/01>P) ﮐﺎﻫﺶ، و ﻣﯿﺰان ﺧﺎك ﻟﺨﺖ (0/01>P) اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ اﺳﺖ. ﮔﻮﻧﻪﻫﺎي ﺧﻮﺷﺨﻮراك .Trigonella monspeliaca L داراي ﺑﯿﺸﺘﺮﯾﻦ درﺻﺪ ﭘﻮﺷﺶ (28/67) در ﭼﺮاي ﺳﺒﮏ و ﺑﯿﺸﺘﺮﯾﻦ ﺗﺮاﮐﻢ (113/57) در ﭼﺮاي ﻣﺘﻮﺳﻂ ﺑﻮد و ﺑﻪ ﺗﺪرﯾﺞ ﺑﺎ اﻓﺰاﯾﺶ ﺷﺪت ﭼﺮا از درﺻﺪ ﮔﻮﻧﻪ ﻫﺎي ﺧﻮﺷﺨﻮراك ﮐﺎﺳﺘﻪ و ﺑﻪ درﺻﺪ ﮔﻮﻧﻪ ﻫﺎي ﮐﻼس II و III اﻓﺰوده ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ﺷﺪت ﭼﺮا از ﻣﻘﺪار رس، ﻣﻨﯿﺰﯾﻢ، اﺳﯿﺪﯾﺘﻪ و ﻣﯿﺎﻧﮕﯿﻦ ﻗﻄﺮ وزﻧﯽ ﺧﺎﮐﺪاﻧﻪ ﮐﺎﺳﺘﻪ ﺷﺪه اﺳﺖ (0/01>P)، وﻟﯽ ﺑﺮ ﻣﻘﺪار ﻣﺎده آﻟﯽ، ﻫﺪاﯾﺖ اﻟﮑﺘﺮﯾﮑﯽ، ﭘﺘﺎﺳﯿﻢ، ﻓﺴﻔﺮ، ﮐﻠﺴﯿﻢ، آﻫﮏ، ﺳﯿﻠﺖ و ﺷﻦ اﻓﺰوده ﺷﺪه اﺳﺖ (0/01>P). ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﭼﺎرﭼﻮب ﮔﺮادﯾﺎن ﭼﺮاﯾﯽ ﻣﻨﺎﺳﺐ ارزﯾﺎﺑﯽ ﺗﺨﺮﯾﺐ ﻣﺮاﺗﻊ ﻣﻐﺎن ﻣﯽ ﺑﺎﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﺑﻪ ﻣﻨﻈﻮر ﻣﺪﯾﺮﯾﺖ اﺻﻮﻟﯽ ﻣﺮاﺗﻊ ﻣﻐﺎن ﭼﺮاي ﻣﺘﻮﺳﻂ ﺗﻮﺻﯿﻪ ﻣﯽ ﮔﺮدد.

To study the effect of grazing gradient in rangeland degradation, the effect of three grazing intensity (light, medium and heavy) on the indicators of vegetation and soil physio-chemical properties in the rangeland of Kolash village of ParsAbad in Ardabil province was evaluated. In each grazing intensity, three transects and in each transect 10 plots of one m² was taken. In each plot the parameters of production and species composition and density, the canopy cover of each species, litter, bare soil and stone and gravel was recorded. Soil samples from a depth of 0 to 30 cm in the plots of first, fifth and tenth of each transect was collected as the one sample. The soil parameters such as pH, electrical conductivity, magnesium, calcium, potassium, lime, phosphorus, organic carbon, organic matter, MWD and the percentages of sand, silt and clay was measured. One-way analysis of variance and Duncan test were used for testing of all parameter means equality and grouping of treatments, respectively. The results showed by increasing grazing intensity, production (p<0/05) and density (p<0/01) have significantly decreased and bare soil (P<0/01) was increased (P<0/01). Trigonella monspeliaca L. as the palatable species, had the highest canopy cover (28/67) in the light gazing and density (113/57) percentage in the medium gazing and gradually by increasing the gazing intensity and species of class II and III were increased. The results showed that by increasing grazing intensity, the amount of Clay, magnesium, pH and MWD was decreased (P<0/01), but the amount of organic carbon, organic matter, electrical conductivity, potassium, phosphorus, calcium, lime, Silt and sand were increased (P<0/01). By considering the results, the grazing gradient framework is suitable for Moghan rangelands degradation assessment. Moreover, for proper management of Moghan rangelands, medium grazing intensity should be considered.