پديد آورندگان :
جمالي، حميد داﻧﺸﮕﺎه ﺷﻬﺮﮐﺮد - داﻧﺸﮑﺪة ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و ﻋﻠﻮم زﻣﯿﻦ , ابراهيمي، عطاالله داﻧﺸﮕﺎه ﺷﻬﺮﮐﺮد - داﻧﺸﮑﺪة ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و ﻋﻠﻮم زﻣﯿﻦ - ﮔﺮوه ﻣﺮﺗﻊ و آﺑﺨﯿﺰداري , قهساره اردستاني، الهام داﻧﺸﮕﺎه ﺷﻬﺮﮐﺮد - داﻧﺸﮑﺪة ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و ﻋﻠﻮم زﻣﯿﻦ - ﮔﺮوه ﻣﺮﺗﻊ و آﺑﺨﯿﺰداري , پردل، فاطمه داﻧﺸﮕﺎه ﺷﻬﺮﮐﺮد - داﻧﺸﮑﺪة ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و ﻋﻠﻮم زﻣﯿﻦ
كليدواژه :
مرتع , تراكم گياهي , اندازه‌گيري تراكم , روش‌هاي فاصله‌اي , گون , مرجن
چكيده فارسي :
ﺗﺮاﮐﻢ ﻣﻬﻢﺗﺮﯾﻦ ﺷﺎﺧﺺ ارزﯾﺎﺑﯽ ﺗﻐﯿﯿﺮ ﺟﻤﻌﯿﺖ ﮔﯿﺎﻫﯽ ﺑﻮده ﮐﻪ روشﻫﺎي ﻣﺨﺘﻠﻔﯽ ﺑﺮاي اﻧﺪازهﮔﯿﺮي آن ﺗﻮ ﺳﻌﻪ ﯾﺎﻓﺘﻪ ﮐﻪ ارزﯾﺎﺑﯽ دﻗﺖ ﻫﺮ روش ﺣﺎﺋﺰ اﻫﻤﯿﺖ زﯾﺎدي ا ﺳﺖ. ﺑﺮاي ارزﯾﺎﺑﯽ روشﻫﺎي ﻓﺎ ﺻﻠﻪاي اﻧﺪازهﮔﯿﺮي ﺗﺮاﮐﻢ ﮔﻮﻧﻪﻫﺎي Astragalus verus و Astragalus albispinus در ﻣﺮاﺗﻊ ا ﺳﺘﭙﯽ ﻣﺮﺟﻦِ ﺑﺮوﺟﻦ، ﻣ ﺴﺎﺣﺘﯽ 32000 ﻣﺘﺮﻣﺮﺑﻌﯽ ﺑﻪ ﻫ ﺸﺖ ﻗﻄﻌﻪ 4000 ﻣﺘﺮﻣﺮﺑﻌﯽ ﺗﻘ ﺴﯿﻢ و ﻧﻤﻮﻧﻪﺑﺮداري ﺷﺪ. در ﻫﺮ ﻗﻄﻌﻪ، ﺑﺎ ﺷــﻤﺎرش ﭘﺎﯾﻪﻫﺎي A. verus و A. albispinus ﻣﻘﺪار واﻗﻌﯽ ﺗﺮاﮐﻢ آنﻫﺎ اﻧﺪازهﮔﯿﺮي و ﯾﮏ ﺗﺮاﻧﺴــﮑﺖ 100 ﻣﺘﺮي ﺑﻪ ﻣﻮازات ﻃﻮل ﻫﺮ ﻗﻄﻌﻪ (100×40ﻣﺘﺮ) ﻣ ﺴﺘﻘﺮ و 10 ﻧﻘﻄﻪ ﺑﻪ ﺻﻮرت ﺗ ﺼﺎدﻓﯽ- ﺳﯿ ﺴﺘﻤﺎﺗﯿﮏ آﻣﺎرﺑﺮداري ﺷﺪ. روشﻫﺎي ﺑﺮآورد ﺗﺮاﮐﻢ ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻓﺮد، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴــﺎﯾﻪ، زوجﻫﺎي ﺗﺼــﺎدﻓﯽ، ﯾﮏ ﭼﻬﺎرم ﻧﻘﻄﮥ ﻣﺮﮐﺰي، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﺑﻪ ﺳــﻮﻣﯿﻦ ﻓﺮد، زاوﯾﮥ ﻣﻨﻈﻢ و ﺗﺮاﻧﺴــﮑﺖ ﻣﺘﻐﯿﺮ در ﻫﺮ ﻧﻘﻄﻪ اﺟﺮا ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧ ﺸﺎن داد ﻣﻘﺎدﯾﺮ واﻗﻌﯽ ﺗﺮاﮐﻢ A. verus ﺑﺮاﺑﺮ 0/1593±0/084 و A. albispinus ﺑﺮاﺑﺮ 0/0622±0/0282 ﭘﺎﯾﻪ در ﻣﺘﺮ ﻣﺮﺑﻊ ﺑﻮد. روشﻫﺎي ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻓﺮد (0/1357±0/1315)، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴﺎﯾﻪ( 0/1368±0/1432)، ﯾﮏ ﭼﻬﺎرم ﻧﻘﻄﮥ ﻣﺮﮐﺰي( 0/0±1016/1646)، زوجﻫﺎي ﺗﺼــﺎدﻓﯽ( 0/0588±0/0536 )، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﺑﻪ ﺳــﻮﻣﯿﻦ ﻓﺮد
( 0/1107±0/0775 ) و ﺗﺮاﻧﺴــﮑﺖ ﻣﺘﻐﯿﺮ ( 0/0±0221/0105 ) ﺑﺮاي A. verus و زاوﯾﮥ ﻣﻨﻈﻢ( 0/0927±0/0523 )، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴــﺎﯾﻪ( 0/0424±0/0357 )، ﻧﺰدﯾﮏﺗﺮﯾﻦ ﺑﻪ ﺳـــﻮﻣﯿﻦ ﻓﺮد( 0/0524±0/0447 ) ﺑﺮاي A. albispinus اﺧﺘﻼف ﻣﻌﻨﯽداري ﺑﺎ ﺷـــﺎﻫﺪ ﻧﺪاﺷـــﺘﻨﺪ. ﻧﺰدﯾﮏﺗﺮﯾﻦ ﺑﺮآورد ﺑﻪ ﺷـــﺎﻫﺪ را ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴﺎﯾﻪ (0/141-) ﺑﺮاي A. verus و ﻧﺰدﯾﮏﺗﺮﯾﻦ ﺑﻪ ﺳﻮﻣﯿﻦ ﻓﺮد (0/0098- ) ﺑﺮاي A. albispinus داﺷﺖ. ﺑﯿﺸﺘﺮﯾﻦ دﻗﺖ را روش ﻧﺰدﯾــﮏﺗﺮﯾﻦ ﻓﺮد (6877/0RMSE= و 0/0026 =SE و 0/1147=CV ) ﺑﺮاي A. verus و ﻧﺰدﯾــﮏﺗﺮﯾﻦ ﻫﻤﺴــــﺎﯾــﻪ (5609/SE= 0/0007 ،SE=0RM و 0/0320 =CV) ﺑﺮاي A. albispinus داﺷـــﺘﻨﺪ. روش ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻓﺮد ﺑﺮاي اﻧﺪازهﮔﯿﺮي ﺗﺮاﮐﻢ ﮔﻮﻧﮥ A. verus و روش ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴﺎﯾﻪ ﺑﺮاي ﮔﻮﻧﮥ A. albispinus ﭘﯿﺸﻨﻬﺎد ﻣﯽﺷﻮد.
چكيده لاتين :
Density is an important indicator of vegetation evaluation, which several methods have been developed for its assessment, but their accuracy is concerned. To reveal accuracy of each methods, a study site of 32000-m2 in the steppe rangeland of Marjan, Boroujen was selected and divided into eight macroplots of 4000-m2. Then, the individuals of Astragalus verus and Astragalus albispinus were counted in each microplots. A transects of 100-m established parallel to the length of the macroplots (40 × 100 mm) and density was measured using closest individual, nearest neighbor, random pairs, point-centered quarter, third closest individual, angle order and variable area transect methods, systematic-randomly in 10 sampling points in each macroplots. The results indicate that the real density of A. verus and A. albispinus were 0.1593±0.084 and 0.0622±0.0282/m2, respectively. Closest individual (0.1357±0.1315/m2), nearest neighbor (0.1368±0.1432/m2), point-centered quarter (0.1016±0.1664/m2), random pairs (0.0588±0.0536/m2), third closest individual (0.1107±0.0775/m2) and variable area transect (0.0221±0.0105/m2) for A. verus and angle order (0.0927±0.0523/m2), nearest neighbor (0.0424±0.0357/m2) and third closest individual (0.0524±0.0447/m2) for A. albispinus showed no significant difference with controls. The results revealed that the closest estimation to the controls belongs to the nearest neighbor (-0.141) and third closest individual (-0.0098) for A. verus and A. albispinus, respectively. Moreover, the nearest neighbor (RMSE=0.6877, SE=0.0026 and R=0.1147) and closest individual (RMSE=0.5609, SE=0.0007, R=0.0320) showed the most precise estimation of densities of A. verus and A. albispinus, respectively. Generally, the closest individual for estimating plant density of A. verus and the nearest neighbor's for A. albispinus are proposed.
