پديد آورندگان :
رضايي سنگدهي، مهدي دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي , فلاح، اصغر دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي , اولادي، جعفر دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي , لطيفي، هومن دانشگاه صنعتي خواجه نصيرالدين طوسي - دانشكده مهندسي نقشه برداري
كليدواژه :
ارتفاع از سطح دريا , چگالي , زي توده روي زميني , سنگده , همبستگي اسپيرمن
چكيده فارسي :
ﺳﺎﺑﻘﻪ و ﻫﺪف: ﺑﺮآورد زي ﺗﻮده و ﻣﺤﺘﻮاي ﮐﺮﺑﻦ درﺧﺘﺎن و ﺳﺎﯾﺮ رﺳﺘﻨﯽ ﻫﺎ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﻫﻤﯿﺖ ﻣﻮﺿﻮع ﮔﺮﻣﺎﯾﺶ زﻣﯿﻦ و ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ از اﻫﻤﯿﺖ زﯾﺎدي ﺑﺮﺧﻮردار ﺑﻮده و ﺗﻌﯿﯿﻦ زي ﺗﻮده ﺑﻪ ﻣﻨﻈﻮر ﺗﺄﺛﯿﺮ آن ﺑﺮ اﻗﻠﯿﻢ و ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ اﻣﺮي ﺿﺮوري ﻣﯽ ﺑﺎﺷﺪ. در ﻣﻨﺎﻃﻖ ﺟﻨﮕﻠﯽ ﮐﻪ ﻫﻤﺮاه ﺑﺎ ﺗﻐﯿﯿﺮات ارﺗﻔﺎﻋﯽ ﻣﯽ ﺑﺎﺷﺪ، ﻣﻌﻤﻮﻻً ﻣﻘﺎدﯾﺮ ﻣﺸﺨﺼﻪ ﻫﺎي ﮐﻤﯽ ﺗﻮده ﻫﺎي ﺟﻨﮕﻠﯽ ﻧﯿﺰ ﺗﻐﯿﯿﺮ ﻣﯽ ﮐﻨﺪ. ﻫﺪف از اﯾﻦ ﭘﮋوﻫﺶ ﺗﻌﯿﯿﻦ اﺛﺮ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ ﺑﺮ ﻣﺸﺨﺼﻪ ﻫﺎي ﮐﻤﯽ ﺟﻨﮕﻞ ﺷﺎﻣﻞ ﺗﻌﺪاد در ﻫﮑﺘﺎر، روﯾﻪ زﻣﯿﻨﯽ، ﻣﻮﺟﻮدي ﺳﺮﭘﺎ، ﻣﻘﺪار زي ﺗﻮده و ﻣﯿﺰان ذﺧﯿﺮه ﮐﺮﺑﻦ در ﺗﻮده ﻫﺎي ﺟﻨﮕﻠﯽ ﺳﺮي ﺳﻪ ﺳﻨﮕﺪه ﻣﯽ ﺑﺎﺷﺪ.
ﻣﻮاد و روش ﻫﺎ: در اﺑﺘﺪا ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺑﻪ ﺳﻪ ﻃﺒﻘﻪ ﺑﺎ داﻣﻨﻪ ارﺗﻔﺎﻋﯽ 1400-1600، 1600-1800 و 1800-2000 ﻣﺘﺮ از ﺳﻄﺢ درﯾﺎ ﺗﻘﺴﯿﻢ ﺷﺪ و در ﻫﺮ ﻃﺒﻘﻪ ﺗﻌﺪاد 50 ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ داﯾﺮه اي ﺑﻪ روش ﺗﺼﺎدﻓﯽ ﻣﻨﻈﻢ ﺑﻪ ﻣﺴﺎﺣﺖ 10 آري ﺑﺎ ﭘﻮﺷﺶ ﺳﺮاﺳﺮي ﮐﻞ ﻃﺒﻘﺎت ارﺗﻔﺎﻋﯽ اﻧﺘﺨﺎب ﮔﺮدﯾﺪ. در ﻫﺮ ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ ﻣﺸﺨﺼﻪ ﻫﺎي ﻧﻮع ﮔﻮﻧﻪ، ارﺗﻔﺎع ﮐﻞ درﺧﺘﺎن و ﻗﻄﺮ ﺑﺮاﺑﺮ ﺳﯿﻨﻪ درﺧﺘﺎن ﺑﺎ ﺑﯿﺶ از 7/5 ﺳﺎﻧﺘﯽ ﻣﺘﺮ ﺛﺒﺖ ﺷﺪ. ﺳﭙﺲ ﭼﮕﺎﻟﯽ ﺗﻤﺎم ﮔﻮﻧﻪ ﻫﺎي ﻣﻮﺟﻮد در ﻗﻄﻌﺎت ﻧﻤﻮﻧﻪ در آزﻣﺎﯾﺸﮕﺎه ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ. ﺑﻌﺪ از آن ﻣﯿﺰان زي ﺗﻮده در ﺳﻄﺢ ﻗﻄﻌﺎت ﻧﻤﻮﻧﻪ ﺑﺮ اﺳﺎس ﻣﺪل ﺟﻬﺎﻧﯽ ﻓﺎﺋﻮ و ﻣﻘﺪار ذﺧﯿﺮه ﮐﺮﺑﻦ روي زﻣﯿﻨﯽ ﻧﯿﺰ ﺑﺎ اﻋﻤﺎل ﺿﺮﯾﺐ ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪ.
ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ ﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن داد ﮐﻪ از ﻃﺒﻘﻪ ارﺗﻔﺎﻋﯽ ﭘﺎﯾﯿﻦ ﺑﻪ ﺑﺎﻻ ﺑﻪ ﺗﺮﺗﯿﺐ ﻣﻘﺎدﯾﺮ ﺗﻌﺪاد در ﻫﮑﺘﺎر ﺑﺮاﺑﺮ ﺑﺎ 477، 384 و 372 اﺻﻠﻪ و روﯾﻪ زﻣﯿﻨﯽ در ﻫﮑﺘﺎر ﺑﺮاﺑﺮ ﺑﺎ 25/58، 29/42 و 30/84 ﻣﺘﺮﻣﺮﺑﻊ ﻣﯽ ﺑﺎﺷﺪ. ﻫﻢ ﭼﻨﯿﻦ ﻣﻘﺎدﯾﺮ ﺣﺠﻢ در ﻫﮑﺘﺎر ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 314/25، 393/98 و 424/75 ﺳﯿﻠﻮ ﺑﺮآورد ﮔﺮدﯾﺪه اﺳﺖ. ﯾﺎﻓﺘﻪ ﻫﺎي اﯾﻦ ﭘﮋوﻫﺶ ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺰان زي ﺗﻮده ﺑﺮاي ﻫﺮ ﺳﻪ ﻃﺒﻘﻪ سيلو برآورد گرديده است. يافته هاي اين پژوهش نشان داد كه ميزان زي توده براي هر سه طبقه ،203/ 522 تن در هكتار و ميزان ذخيره كربن نيز به ترتيب 34 / 478 و 30 /26 ،406/ ارتفاعي از پايين به بالا به ترتيب برابر با 68 239/12 و 261/15 ﺗﻦ در ﻫﮑﺘﺎر ﺑﺮآورد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ روﻧﺪ ﺻﻌﻮدي را ﻧﺸﺎن ﻣﯽ دﻫﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﺗﺠﺰﯾﻪ وارﯾﺎﻧﺲ ﺑﯿﺎﻧﮕﺮ اﺧﺘﻼف ﻣﻌﻨﯽ دار ﺑﯿﻦ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ ﺑﺎ ﻣﺸﺨﺼﻪ ﻫﺎي ﻣﻮرد ﻧﻈﺮ ﺑﻪ اﺣﺘﻤﺎل 0/95 دارد. ﻫﻢ ﭼﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻫﻤﺒﺴﺘﮕﯽ اﺳﭙﯿﺮﻣﻦ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺑﯿﻦ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ و ﻣﺸﺨﺼﻪ ﻫﺎي ﺗﻌﺪاد درﺧﺘﺎن، روﯾﻪ زﻣﯿﻨﯽ، ﺣﺠﻢ و زي ﺗﻮده روي زﻣﯿﻨﯽ در ﻫﮑﺘﺎر ﻫﻤﺒﺴﺘﮕﯽ ﻣﻌﻨﯽ داري در ﺳﻄﺢ 99 درﺻﺪ وﺟﻮد دارد. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: در ﻣﺠﻤﻮع ﻧﺘﺎﯾﺞ اﯾﻦ ﭘﮋوﻫﺶ در ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﺗﻐﯿﯿﺮات ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ ﻣﻮﺟﺐ ﺗﻐﯿﯿﺮ در ﺑﺮﺧﯽ ﻣﺸﺨﺼﻪﻫﺎي ﮐﻤﯽ ﺗﻮدهﻫﺎي ﺟﻨﮕﻠﯽ ﺷﺪه و ﺑﺪﯾﻦ ﺗﺮﺗﯿﺐ ﮔﺮادﯾﺎن ارﺗﻔﺎع ﺑﺮ ﺗﻮزﯾﻊ ﻣﻘﺎدﯾﺮ زيﺗﻮده روي زﻣﯿﻨﯽ ﻣﺆﺛﺮ ﺑﻮده، ﺑﻪ ﻃﻮري ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ، ﻣﻘﺪار زﯾﺴﺖ ﺗﻮده ﻧﯿﺰ اﻓﺰاﯾﺶ داﺷﺘﻪ و در اﯾﻦ ﻣﯿﺎن ﻣﻘﺎدﯾﺮ زي ﺗﻮده روي زﻣﯿﻨﯽ، ﺑﯿﺶ ﺗﺮﯾﻦ ﻫﻤﺒﺴﺘﮕﯽ را ﺑﺎ ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ ﻧﺸﺎن داده اﺳﺖ.
چكيده لاتين :
Background and objectives: Estimating the biomass and carbon content of trees and the other crops is important, in particular in context of global warming and climate change resilience and the determination of biomass in order to influence the climate and management of natural resources is essential. In forest areas with high altitudinal gradients, values of the quantitative characteristics of forest stands usually change. The purpose of this study was to determine the effect of altitudinal gradient on quantitative forest characteristics including number per hectare, basal area, standing volume, biomass and carbon storage in District-3 of Sangdeh Forests.
Materials and methods: The area was initially divided into three altitudinal levels, with a range of 1600-1400, 1600-1800 and 1800-2000 m altitude sea level 50 circular sample plots were randomly assigned to each level, resulting in a total sampled area of 10 ares (0.1ha) to cover each level. In each plot, species type, height and diameter at breast height were recorded for all trees with DBH > 7.5 cm. Then, the density of all species was determined by sampling followed by further analysis in laboratory. Then, the biomass was calculated in the sample plots based on the FAO global model.
Results: The results showed that altitude gradient from the bottom up, the number of trees per ha of 477, 384 and 372, the basal area of 25.58, 29.49 and 30.84 m2, respectively. Also the volume per ha were estimated to be of 314.25, 393.98 and 424.75 silve, respectively. The results this research showed the amount of AGB for all three altitudinal levels based on gradient increase is 406.68, 478.26 and 522.30 t ha-1, and carbon stock of 203/34, 239/12, and 261/15 ton per hectare, respectively, that shows an upward trend as the a.s.l. increases. The analysis of variance indicated a significant difference between the altitude and the characteristics (P < 0.05). In addition, Spearman correlation showed that there was a significant correlation between altitude and tree characteristics, basal area, standing volume, aboveground biomass per ha (p<0.01).
Conclusion: Conclusively, the results of this research in the study area show that changes in altitude from the sea level have caused changes in some of the quantitative characteristics and thus the elevation gradient has been effective on the distribution of AGB, so that with increasing a.s.l, the amount of AGB has also increased and AGB has the highest correlation with the altitude from the sea level
