ارزيابي تأثير جاده سازي جنگل بر زادآوري (مطالعه موردي: طرح جنگلداري سيستان، گيلان)

Evaluation of forest road construction on regeneration (Case Study: Sistan,s forest management plan, Guilan)

زﻣﯿﻨﻪ و ﻫﺪف: از وﻗﺎﯾﻊ ﻣﻬﻢ در زﻧﺪﮔﯽ ﺟﻨﮕﻞ، زادآوري درﺧﺘﺎن ﺟﻨﮕﻠﯽ اﺳﺖ ﮐﻪ ﺗﺪاوم ﺣﯿﺎت و ﭘﺎﯾﺪاري داﯾﻤﯽ ﯾﮏ ﺟﻨﮕﻞ از درﺧﺘﺎن ﻣﺨﺘﻠﻒ،ﺑﻪ آن ﻫﺎ ﺑﺴﺘﮕﯽ دارد. ﺑﻨﺎﺑﺮاﯾﻦ ﺷﻨﺎﺧﺖ ﻋﻮاﻣﻞ ﻣﺆﺛﺮ ﺑﺮ روﻧﺪ اﺳﺘﻘﺮار ﮔﻮﻧﻪﻫﺎي ﺟﻨﮕﻠﯽ ﻣﯽﺗﻮاﻧﺪ ﻣﺎ را در ﺷﻨﺎﺧﺖ ﺑﻬﺘﺮ ﻣﺮاﺣﻞ ﻣﺨﺘﻠﻒ ﺗﻮاﻟﯽ اﯾﻦ اﮐﻮﺳﯿﺴﺘﻢ ﯾﺎري ﮐﻨﺪ. ﻫﺪف اﯾﻦ ﻣﻘﺎﻟﻪ ﺑﺮرﺳﯽ ﺗﺄﺛﯿﺮ ﺗﻮﺳﻌﻪ ﺟﻨﮕﻞ ﺑﺮ زادآوري ﮔﻮﻧﻪﻫﺎي ﭼﻮﺑﯽ درﺧﺘﯽ و درﺧﺘﭽﻪاي در ﻣﻨﻄﻘﻪ ذﯾﻠﮑﯽ رودﺑﺎر اﺳﺖ. روش ﺑﺮرﺳﯽ: ﺑﺮاي اﻧﺠﺎم اﯾﻦ ﺗﺤﻘﯿﻖ، ﻗﺴﻤﺘﯽ از ﺟﺎده ﺟﻨﮕﻠﯽ ﺳﺮي 4 ذﯾﻠﮑﯽ رود ﺑﺎ ﺳﻦ 18 ﺳﺎل ﮐﻪ ﺑﻪ ﻟﺤﺎظ ارﺗﻔﺎع، ﺟﻬﺖ داﻣﻨﻪ، ﺗﻐﯿﯿﺮات ﺷﯿﺐ و ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪاي داراي وﺿﻌﯿﺖ ﯾﮑﻨﻮاﺧﺘﯽ ﺑﻮد، ﺑﺎ ﻃﻮل ﮐﺎﻓﯽ )500 ﻣﺘﺮ( اﻧﺘﺨﺎب و در ﺟﺎده 6 ﺗﺮاﻧﺴﮑﺖ، ﺑﻪ ﻃﻮر ﯾﮏ درﻣﯿﺎن ﺑﻪ ﺳﻤﺖ ﺑﺎﻻ و ﭘﺎﯾﯿﻦ داﻣﻨﻪ و ﺑﻪ ﻃﻮل 50 ﻣﺘﺮ و ﻋﻤﻮد ﺑﺮ آن ﺑﺎ اﺳﺘﻔﺎده از ﻃﻨﺎب و ﻗﻄﺐ ﻧﻤﺎ ﭘﯿﺎده ﮔﺮدﯾﺪ. در ﻫﺮ ﺗﺮاﻧﺴﮑﺖ در ﻓﻮاﺻﻞ 30 ،10 ،5 ،1 و 50 ﻣﺘﺮ، ﭘﻼت ﻫﺎي ﻣﻮازي ﺑﺎ ﺟﺎده و ﺑﻪ اﺑﻌﺎد 2 ﻣﺘﺮ در 10 ﻣﺘﺮ ﭘﯿﺎده ﺷﺪ و در داﺧﻞ ﻫﺮ ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ، ﻧﻮع و ﺗﻌﺪاد زادآوري ﮔﻮﻧﻪﻫﺎي ﭼﻮﺑﯽ درﺧﺘﯽ و درﺧﺘﭽﻪاي ﺑﺮداﺷﺖ ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﺑﺮ ﻃﺒﻖ ﻧﺘﺎﯾﺞ، ﺗﻔﺎوت آﻣﺎري ﻣﻌﻨﺎداري ﺑﯿﻦ ﻣﯿﺎﻧﮕﯿﻦ ﺗﻌﺪاد زادآوري ﮔﻮﻧﻪﻫﺎ در ﭘﺎﯾﯿﻦ دﺳﺖ )13/9± 28/8( و ﺑﺎﻻ دﺳﺖ ﺟﺎده )4±12/9 /32( وﺟﻮد ﻧﺪاﺷﺖ. آﻧﺎﻟﯿﺰ وارﯾﺎﻧﺲ ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺎﻧﮕﯿﻦ ﺗﻌﺪاد زادآوري ﺑﯿﻦ ﻓﻮاﺻﻞ ﻣﺨﺘﻠﻒ در ﭘﺎﯾﯿﻦ دﺳﺖ و ﺑﺎﻻ دﺳﺖ ﺟﺎده داراي اﺧﺘﻼف ﻣﻌﻨﯽداري ﻣﯽﺑﺎﺷﺪ. در ﭘﺎﯾﯿﻦ دﺳﺖ ﺟﺎده، ﺑﻪ اﺣﺘﻤﺎل 95 درﺻﺪ، ﻣﯿﺎﻧﮕﯿﻦ ﺗﻌﺪاد زادآوري در ﻓﺎﺻﻠﻪ 5 و 1 ﻣﺘﺮ از ﺟﺎده ﺑﻪ ﺗﺮﺗﯿﺐ داراي ﺑﯿﺶ ﺗﺮﯾﻦ )7/0± 39/0( و ﮐﻢ ﺗﺮﯾﻦ ﻣﻘﺪار )10/4± 16/0( ﻣﯽﺑﺎﺷﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﺮاي ﺑﻘﺎء ﻫﺮ ﻧﻮع ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ، اﻣﮑﺎن زادآوري اﻫﻤﯿﺖ وﯾﮋهاي دارد و از آﻧﺠﺎ ﮐﻪ ﺟﺎدهﻫﺎ، ﻣﺴﯿﺮﻫﺎي دﺳﺖ ﯾﺎﺑﯽ ﺑﻪ اﮐﻮﺳﯿﺴﺘﻢﻫﺎي ﺟﻨﮕﻠﯽ، ﻫﻢ ﺑﺮاي اﻧﺴﺎن و ﻫﻢ ﺑﺮاي ﮔﻮﻧﻪﻫﺎي ﮔﯿﺎﻫﯽ و ﺟﺎﻧﻮري ﻣﻬﺎﺟﻢ ﻣﺤﺴﻮب ﻣﯽﺷﻮد، آﮔﺎﻫﯽ از ﺷﺮاﯾﻂ ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ و ﺧﺎك ﻣﻨﻄﻘﻪ ﺗﺤﺖ ﻣﺪﯾﺮﯾﺖ و ﺑﺮرﺳﯽ ﻣﺴﯿﺮﻫﺎي ﺟﺎده ﺟﻨﮕﻠﯽ ﺑﻪ ﻣﻨﻈﻮر ﺑﻪ ﺣﺪاﻗﻞ رﺳﺎﻧﺪن ﺧﺴﺎرات وارده ﺑﻪ زادآوري ﺿﺮوري ﻣﯽﺑﺎﺷﺪ.

Background and Objective: One of the most important events in forests is the regeneration of forest trees on which the sustainability of a forest depends. Therefore, understanding the factors affecting the establishment of forest species can help us of better understanding the different stages of the succession of this ecosystem. The purpose of this paper is to investigate the effect of forest development on regeneration of tree species in Zilaki area of Rudbar town. Method: In this study, a part of forest roads in Series 4 of Zilaki rood at the age of 18 was selected in terms of homogeneity of height, aspect, slope changes and species composition status and with sufficient length (500 m). In this road, 6 transect was designed and parallel plots were implemented at intervals of 1, 5, 10, 30 and 50 meters, with dimensions of 2 in 10 meters. The number and type of wooden trees and shrub species regeneration were sampled. Findings: According to the results, there was no significant difference between the mean regeneration of the species in the downstream (28.8 ± 13.9) and upstream of the road (32.4 ± 12.9). Analysis of variance showed that the mean number of regeneration between different intervals in the downstream and upstream of the road had a significant difference. In downstream, with a probability of 95%, the average number of regeneration were (39.0 ± 7.0) and (16.1 ± 10.4) at 5 and 1 meter of the road, respectively. Discussion and Conclusions: For the survival of any vegetation, the possibility of regeneration is so important and since the roads as the access routes to forest ecosystems are important both for humans and invasive plant species, road ecology studies is very important and valuable to monitor and control the impact of forest roads on biodiversity. So, the knowledge about the flora and edaphic conditions is essential to minimize the damage to vegetation and soil in the region influenced by forest roads