Impact of dead trees on natural regeneration in forest stands (Chelir district, Kheiroudkenar, Nowshahr)

Document Type : Research article

Authors

1 Member of scientific board, Islamic Azad University, Shabestar branch

2 Professor, Faculty of Natural Resources, University of Tehran.

3 Associate professor, Faculty of Natural Resources, University of Tehran.

Abstract

The main objective of this study which was conducted in an intact stand of the experimental Kheiroudkenar forest (Chelir district), was to examine the ecological importance of dead trees followed by it’s impact on natural regeneration of the forest. In this study the seedlings around dead trees were recorded in a 50 ha stand, where the dead trees were divided into four decay classes. Considering the decay classes, results indicated that; there were different kinds of establishment of regeneration. The highest numbers of seedlings were accounted around dead trees classified in 3rd decay class, while 4, 2 and 1 decay classes were in the next orders. Gap opening related to dead trees had important effects on establishment of the regeneration. Results showed that with increasing of decay classes, size of gaps decreased. In this study gaps were divided into five groups, including close gap (closed canopy), very small (0-12.5 m2), small (12.5-50 m2), medium size gap (50-113 m2) and large size or open canopy (>113 m2). Abundance of seedlings under the closed gaps of stand crown was maximum, while the numbers of seedlings were reduced under the medium gap size, very small, small and large size, respectively. One way analysis of variance showed that there was no significant difference (at 5% significant level) among the number of seedlings around dead trees with different decay classes, however there was a significant difference among abundance of seedlings under different gap sizes, produced by dead trees. Therefore, gap opening caused by dead trees, had higher effect on establishment of regeneration than decay classes.   
 

Keywords

References

 - حبشی، ه.، 1376. بررسی اهمیت جنگل‌شناسی خشکه‌دارها در جنگل های بکر راش منطقه "واز". پایان‌نامه کارشناسی ارشد، دانشکده منابع طبیعی دانشگاه تربیت مدرس، 127 صفحه.
- ساجدی، ت.، 1381، بررسی تغییرات تیپ هوموس در جنگلهای خالص و آمیخته راش، سری چلیر. پایان‌نامه کارشناسی ارشد، دانشکده منابع طبیعی دانشگاه تهران، 140 صفحه.
-  محمدنژاد کیاسری، ش. و رحمانی، ر.،1380. تأثیر خشکه‌دارها بر فراوانی تجدید حیات طبیعی در یک جنگل آمیخته راش و ممرز (سری جمال الدین کلا، مازندران). مجله منابع طبیعی ایران، 54 (2): 151-143.
-  مروی مهاجر، م.، 1381. جزوه درسی جنگل‌شناسی تکمیلی. دانشکده منابع طبیعی، دانشگاه تهران، 54 صفحه.
-  موسوی، س.، ثاقب طالبی، خ.، طبری، م. و پورمجیدیان، م.، 1382. تعیین اندازه سطح حفره تاج پوشش برای بهبود زادآوری طبیعی راش. مجله منابع طبیعی ایران، 56 (1و2 ) : 46-39.
 - Brokaw, N. and Busing, R., 2000. Niche versus chance and tree diversity in forest gaps. United  states forestry sciences laboratory: 183-192.
- Clinton, B., 1988. Regeneration patterns in canopy gaps of mixed-oak forest of the southern Appalachians, Influences of Topographic position and evergreen understory. U.S.A forest resources and institute of ecology, 132: 308-319.
-Lanter, O. and Pardos, M., 2000. Effects of canopy opening on height and diameter growth in naturally regenerated beech seedlings. France, Department of silviculture, 58: 127-134.
-Lowis, T., 1998. Dead and dying trees essential for life in the forest. 52: 158-172.
-Wright, F., Dave, K. and Bartemucci, P., 1998. Regeneration from seed of six tree species in the interior cedar-hemlock forests of British Columbia as affected by substrate and canopy gap position. Canada, British Columbia forest service, 28: 1352-1364.
Iranian Journal of Forest and Poplar Research
Volume 15, Issue 3 - Serial Number 29
October 2007
Pages 240-234

Files

Share

How to cite

Statistics