پديد آورندگان :
ميردارهريجاني، مهدي دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي , حجتي، محمد دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي - گروه جنگلداري , پورمجيديان، محمدرضا دانشگاه علوم كشاورزي و منابع طبيعي ساري - دانشكده منابع طبيعي - گروه جنگلداري , كوچ، يحيي دانشگاه تربيت مدرس - دانشكده منابع طبيعي و علوم دريايي نور - گروه مرتعداري
كليدواژه :
جنگل پهن برگ , لايه آلي , زي توده ريز ريشه , كرم خاكي , تنفس ميكروبي
چكيده فارسي :
ﺳﺎﺑﻘﻪ و ﻫﺪف: ﺗﻮده ﺟﻨﮕﻠﯽ ﻧﻘﺶ ﻣﻬﻤﯽ در ﻋﻤﻠﮑﺮد ﺑﻮمﺳﺎزﮔﺎن، ﮐﻤﯿﺖ و ﮐﯿﻔﯿﺖ ﻣﺎده آﻟﯽ ﺗﻮﻟﯿﺪﺷﺪه، ﻋﻨﺎﺻﺮ ﻏﺬاﯾﯽ و درﻧﺘﯿﺠﻪ ﺷﺎﺧﺺﻫﺎي زﯾﺴﺘﯽ ﺧﺎك دارد. اﺛﺮ ﮔﻮﻧﻪﻫﺎي درﺧﺘﯽ ﺧﺰانﮐﻨﻨﺪه در ﺗﻮدهﻫﺎي ﺧﺎﻟﺺ و آﻣﯿﺨﺘﻪ ﺑﺮ روي ﻓﺮآﯾﻨﺪﻫﺎي ﺧﺎك، ﮐﻢ ﺗﺮ ﻣﻮرد ﺗﻮﺟﻪ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺑﻨﺎﺑﺮاﯾﻦ، اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ ﻫﺪف ﺑﺮرﺳﯽ ﺗﻐﯿﯿﺮﭘﺬﯾﺮي ﺑﺮﺧﯽ از ﻣﺸﺨﺼﻪ ﻫﺎي زﯾﺴﺘﯽ ﺧﺎك در ﺗﻮدهﻫﺎي ﺟﻨﮕﻠﯽ راش و ﻣﻤﺮز ﺑﺎ ﻧﺴﺒﺖ ﺗﺮﮐﯿﺐ ﻣﻌﯿﻦ اﻧﺠﺎم ﺷﺪ ﮐﻪ ﺗﺎﮐﻨﻮن ﮔﺰارﺷﯽ از آن ﻣﺸﺎﻫﺪه ﻧﺸﺪه اﺳﺖ.
ﻣﻮاد و روش ﻫﺎ: در اﯾﻦ ﻣﻄﺎﻟﻌﻪ 5 ﺗﺮﮐﯿﺐ ﺗﻮده ﺟﻨﮕﻠﯽ )1. راش ﺧﺎﻟﺺ، 2. ﻣﻤﺮز ﺧﺎﻟﺺ، 3. راش و ﻣﻤﺮز، 4. راش- ﻣﻤﺮز، 5. ﻣﻤﺮز- راش( ﺑﺎ 5 ﺗﮑﺮار در ﻫﺮ ﺗﻮده و ﻧﻤﻮﻧﻪﺑﺮداري در 3 ﺑﺨﺶ )ﺷﺮق، ﻣﺮﮐﺰ و ﻏﺮب( ﻧﺎﺣﯿﻪ روﯾﺸﯽ ﻫﯿﺮﮐﺎﻧﯽ )ﻣﺠﻤﻮﻋﺎً 75 ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ( در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪ. ﻧﻤﻮﻧﻪﺑﺮداري ﺑﻪ ﺻﻮرت ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ اﻧﺘﺨﺎﺑﯽ، ﺑﻪ ﺷﮑﻞ داﯾﺮهاي در ﻣﺮﮐﺰ ﻫﺮ ﺗﻮده، ﺑﺎ ﻣﺴﺎﺣﺖ 10 آر و ﺷﺮاﯾﻂ ﯾﮑﺴﺎن ﺟﻬﺖ داﻣﻨﻪ )ﺷﻤﺎل ﺷﺮﻗﯽ(، ﺷﯿﺐ )30-60 درﺻﺪ(، ارﺗﻔﺎع از ﺳﻄﺢ درﯾﺎ )ﻣﯿﺎﻧﮕﯿﻦ 1200 ﻣﺘﺮ( و ﺗﻮده داراي درﺧﺘﺎن ﻣﯿﺎن ﺳﺎل )ﻗﻄﺮ 40-60 ﺳﺎﻧﺘﯽﻣﺘﺮ( ﺑﺮاي ﺑﺮداﺷﺖ ﻫﺮ ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ )ﺟﻬﺖ ﺑﺮﻗﺮاري ﺷﺮاﯾﻂ ﯾﮑﺴﺎن( در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪه اﺳﺖ. ﻧﻤﻮﻧﻪﺑﺮداري از ﻻﯾﻪﻫﺎي آﻟﯽ و ﺧﺎك ﻣﻌﺪﻧﯽ از ﺳﻄﺢ 25×25 و ﻋﻤﻖ 0-10 ﺳﺎﻧﺘﯽﻣﺘﺮ در ﻣﺮﮐﺰ و ﭼﻬﺎر ﺟﻬﺖ اﺻﻠﯽ ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ ﺻﻮرت ﭘﺬﯾﺮﻓﺖ. ﺗﺠﺰﯾﻪ وﺗﺤﻠﯿﻞ ﻫﺎي آﻣﺎري ﺑﺎ اﺳﺘﻔﺎده از ﺗﺠﺰﯾﻪ وارﯾﺎﻧﺲ ANOVA و ﻣﻘﺎﯾﺴﺎت ﭼﻨﺪﮔﺎﻧﻪ داﻧﮑﻦ در ﻧﺮماﻓﺰار 20 SPSS، ﻫﻢ ﭼﻨﯿﻦ ﺑﺎ اﺳﺘﻔﺎده از ﺗﺠﺰﯾﻪ وﺗﺤﻠﯿﻞ ﻣﺆﻟﻔﻪ ﻫﺎي اﺻﻠﯽ ﯾﺎ PCA ﺑﻪ وﺳﯿﻠﻪ ﻧﺮم اﻓﺰار 0 5. .PC-Ord V ﺻﻮرت ﭘﺬﯾﺮﻓﺖ.
ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد، ﮐﺮﺑﻦ ﻻﯾﻪ آﻟﯽ در ﺗﻮده راش ﺧﺎﻟﺺ )49/73 درﺻﺪ( و ﻧﯿﺘﺮوژن ﻻﯾﻪ آﻟﯽ در ﺗﻮده ﻣﻤﺮز ﺧﺎﻟﺺ )2/57 درﺻﺪ( ﺗﻔﺎوت ﻣﻌﻨﯽ دار داﺷﺘﻪ و ﺑﺎﻻﺗﺮﯾﻦ ﻣﻘﺪار را دارد. ﮐﺮﺑﻦ آﻟﯽ )5/17 درﺻﺪ( و ﻧﺴﺒﺖ ﮐﺮﺑﻦ ﺑﻪ ﻧﯿﺘﺮوژن )28/17( ﺧﺎك در ﺗﻮده راش ﺧﺎﻟﺺ داراي ﺗﻔﺎوت ﻣﻌﻨﯽدار ﺑﻮده و ﺑﯿﺶ ﺗﺮﯾﻦ ﻣﻘﺪار را ﻧﺸﺎن داد، درﺣﺎﻟﯽﮐﻪ واﮐﻨﺶ )pH( )7/10( و ﻧﯿﺘﺮوژن )0/50 درﺻﺪ( ﺧﺎك در ﺗﻮده ﻣﻤﺮز ﺧﺎﻟﺺ داراي ﺗﻔﺎوت ﻣﻌﻨﯽدار ﺑﻮده و ﻣﻘﺎدﯾﺮ ﺑﺎﻻﺗﺮي را ﻧﺸﺎن داد. زيﺗﻮده رﯾﺰ رﯾﺸﻪ )93/36 ﮔﺮم ﺑﺮ ﻣﺘﺮﻣﺮﺑﻊ(، ﺗﺮاﮐﻢ و زيﺗﻮده ﮐﻞ ﮔﺮوهﻫﺎي اﮐﻮﻟﻮژﯾﮏ ﮐﺮمﻫﺎي ﺧﺎﮐﯽ )ﺑﻪ ﺗﺮﺗﯿﺐ 2/47 ﻋﺪد در ﻣﺘﺮﻣﺮﺑﻊ و 32/08 ﻣﯿﻠﯽﮔﺮم در ﻣﺘﺮﻣﺮﺑﻊ( و ﺗﻨﻔﺲ ﻣﯿﮑﺮوﺑﯽ )0/53 ﻣﯿﻠﯽﮔﺮم دي اﮐﺴﯿﺪ ﮐﺮﺑﻦ در ﮔﺮم ﺧﺎك در روز( در ﺗﻮده ﻣﻤﺮز ﺧﺎﻟﺺ داراي ﺗﻔﺎوت ﻣﻌﻨﯽدار ﺑﻮده و ﺑﯿﺶ ﺗﺮﯾﻦ ﻣﻘﺎدﯾﺮ را ﻧﺴﺒﺖ ﺑﻪ ﺳﺎﯾﺮ ﺗﻮدهﻫﺎي ﻣﻮردﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن داد. در اﯾﻦ ﭘﮋوﻫﺶ ﺗﺠﺰﯾﻪ وﺗﺤﻠﯿﻞ ﻣﺠﻤﻮع ﻣﺸﺨﺼﻪﻫﺎي ﻣﻮردﺑﺮرﺳﯽ ﺑﺮ روي ﻣﺤﻮرﻫﺎي اول و دوم آﻧﺎﻟﯿﺰ PCA ﺑﻪ ﺗﺮﺗﯿﺐ 47/62 و 14/22 درﺻﺪ وارﯾﺎﻧﺲ را ﺗﻮﺟﯿﻪ ﻣﯽﮐﻨﺪ ﮐﻪ ﺑﯿﺶ ﺗﺮﯾﻦ ﻓﻌﺎﻟﯿﺖ زﯾﺴﺘﯽ ﻣﻮردﺑﺮرﺳﯽ ﺧﺎك را در ﺗﻮدهﻫﺎي ﻣﻤﺮز ﺧﺎﻟﺺ و ﻣﻤﺮز ﻏﺎﻟﺐ ﻧﺴﺒﺖ ﺑﻪ راش ﺧﺎﻟﺺ و راش ﻏﺎﻟﺐ ﻧﺸﺎن ﻣﯽدﻫﺪ. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﻪ ﻃﻮرﮐﻠﯽ ﻧﺘﺎﯾﺞ اﯾﻦ ﺑﺮرﺳﯽ ﺑﯿﺎﻧﮕﺮ آن اﺳﺖ ﮐﻪ ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪ درﺧﺘﯽ ﻣﻤﺮز در ﺗﻮدهﻫﺎي راش، ﺳﺒﺐ ﺗﻔﺎوتﻫﺎي ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ ﺑﺮ ﺑﻬﺒﻮد ﺷﺎﺧﺺﻫﺎي زﯾﺴﺘﯽ ﺧﺎك ﻣﯽﺷﻮد ﮐﻪ در ﺗﻨﻈﯿﻢ آﻣﯿﺨﺘﮕﯽ و ﺟﻨﮕﻞﮐﺎري در ﺟﻨﮕﻞﻫﺎي ﺗﺨﺮﯾﺐ ﯾﺎﻓﺘﻪ، ﺑﺮ ﺣﻀﻮر ﮔﻮﻧﻪ ﻣﻤﺮز در ﺗﻮده راش ﺧﺎﻟﺺ ﺗﺄﮐﯿﺪ ﻣﯽﺷﻮد. از ﯾﺎﻓﺘﻪﻫﺎي اﯾﻦ ﺑﺮرﺳﯽ ﻣﯽ ﺗﻮان در اوﻟﻮﯾﺖ ﺑﻨﺪي اﻧﺘﺨﺎب ﺗﻮدهﻫﺎﯾﯽ ﻣﺘﺸﮑﻞ از ﮔﻮﻧﻪﻫﺎي درﺧﺘﯽ راش و ﻣﻤﺮز ﺟﻬﺖ ﺗﻨﻈﯿﻢ آﻣﯿﺨﺘﮕﯽ در ﻋﻤﻠﯿﺎت ﭘﺮورﺷﯽ و اﺣﯿﺎي ﻣﻨﺎﻃﻖ ﺟﻨﮕﻠﯽ ﺗﺨﺮﯾﺐ ﯾﺎﻓﺘﻪ ﺷﻤﺎل ﮐﺸﻮر ﺑﻬﺮه ﺑﺮد؛ ﺑﻨﺎﺑﺮاﯾﻦ، ﭘﯿﺸﻨﻬﺎد ﻣﯽﺷﻮد ﮐﻪ در ﻫﻨﮕﺎم ﻋﻤﻠﯿﺎت ﻧﺸﺎﻧﻪ ﮔﺬاري، ﺑﺮﻧﺎﻣﻪرﯾﺰيﻫﺎي ﻣﺪﯾﺮﯾﺘﯽ و ﺟﻨﮕﻞﮐﺎري در روﯾﺸﮕﺎهﻫﺎي اﯾﻦ دو ﮔﻮﻧﻪ، ﺣﻔﻆ آﻣﯿﺨﺘﮕﯽ آن ﻫﺎ در اوﻟﻮﯾﺖ ﻗﺮار ﮔﯿﺮد.
چكيده لاتين :
Background and Objectives: Forest stands have an important role in the ecosystem function, quantity and quality of produced organic matter, nutrients and finally soil biological characteristics. In pure and mixed stands, effects of deciduous tree species on soil processes have been received less attention. Therefore, this study aimed to investigate the variability of some soil biological characteristics in beech and hornbeam forest stands with a certain composition ratio, which has not been reported so far.
Materials and Methods: In this study, 5 combinations of forest stands (1. pure beech, 2. pure hornbeam, 3. beech and hornbeam, 4. beech-hornbeam, 5. hornbeam-beech) were considered by 5 sample plots replications in each stand in 3 parts (east, center and west) of Hyrcanian region (total of samples were 75). Sampling as a selected sample plots are considered circle form (1000 m2) in the center of each stands, with same conditions for aspect (northeast), slope (30-60%), altitude (average 1200 m) and the stands with middle-aged trees (diameter 40-60 cm) to each sample (for establishment the same conditions). Sampling of organic layers and mineral soil from 25 × 25 area and 0-10 cm depth was performed in the center of each sample plot and four main directions. Statistical analyzes were performed using ANOVA analysis of variance and Duncan multiple comparisons in SPSS 20 software, also using principal component analysis or PCA by PC-Ord V. 5. 0 software.
Results: The results showed that the organic layer carbon in pure beech (49.73%) and organic layer nitrogen in pure hornbeam (2.57%) stands had significant difference and had the highest measured value. Soil organic carbon (5.17%) and C/N (28.17%) had significant difference in pure beech and showed the highest measured amount, while soil pH (7.10) and N (0.50%) had significant difference and showed the highest values in pure hornbeam stands. Fine root biomass (93.36 g m-2), density and biomass of total earthworm ecological groups (respectively 2.47 n m-2 and 32.08 mg m-2) and microbial respiration (0.53 mg CO2 g-1 day-1) were significantly different in pure hornbeam stands and showed the highest values compared to other studied stands. In this study, the analysis of all the characteristics studied on the first and second axes of PCA analysis justifies 47.62 and 14.22 percent of variance, respectively, which shows the highest soil biological activity in pure hornbeam and dominant hornbeam stands compared to pure beech and dominant beech.
Conclusion: In general, the results of this study indicated that the composition of hornbeam tree species in beech stands caused significant differences in the improvement of soil biological indicators, so it was verified for mixing regulation and afforestation on the presence of hornbeam species in pure beech stands. The findings of this study can be used to prioritize the selection of stands consisting of beech and hornbeam tree species to regulate mixture in breeding operations and rehabilitate degraded areas in the north of Iran. Therefore, it is suggested that during marking operations, management planning and afforestation in the habitats of these two species, maintaining their mixture should be a priority.
