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Long-term effect of fire on herbaceous species diversity in oriental beech (Fagus orientalis Lipsky) forests in northern iran

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Forestry Studies in China 2012年第4期14卷 260-267页

作者： Mohammad Naghi ADEL Hassan POURBABAEI Ali OMIDI David POTHIER Department of Forestry Natural Resources FacultyUniversity of Guilan Department of Forestry Natural Resources Office Centre d'étude de la forêt (CEF) et Département des sciences du bois et de la forêt Pavillon Abitibi-Price2405 rue de la TerrasseUniversité Laval

We studied the long-term impacts of natural burning on herbaceous species diversity 37 years after a fire occurred in the Roudbar forests of Guilan Province, northern iran. Numerous studies have examined short-term changes in understory vegetation following wildfire; however, very few long-term studies are available or changes inferred from retrospective studies based on chro- nosequences. For this study, 170 ha of forest （85 ha, burned areas; 85 ha, unburned areas） were surveyed. Because the 1000 m2 plots were too large for detailed measurements of herbaceous species, we determined a sub-sample size according to the Whittaker＇s nested plot sampling protocol and minimal areas method. Hence, sub-plots of 32 m2 were used for herbaceous species measurements, which consisted of percent cover of each species based on the Domin criterion. We measured plant diversity （Shannon-Wiener index）, spe- cies richness （Margalef＇s index）, and evenness （Smith-Wilson index）. Mean percent cover, together with diversity, richness and even- ness, increased markedly in burned areas compared to unburned controls. This suggests that the biodiversity of these forests could be restored within 37 years after fire. However, the abundance of invasive species such as Rubus fruticosus and Bromus benekenii increased significantly in burned areas, but these could be controlled by relevant silvicultural operations.

关键词： fire diversity richness evenness beech forest northern iran

Effect of thinning on growth of Acer velutinum Boiss. in northern forests of iran

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Forestry Studies in China 2013年第4期15卷 320-324页

作者： Alireza ESLAMI M.R.JAHANARA S.A.HASHEMI Department of Agriculture Rasht Branch Islamic Azad University Natural Racecourses Organization Department of Forestry Lahijan Branch Islamic Azad University

It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in iran. Acer velutinum, an endemic species in iran, is often planted in monocultures or in a mixture with other endemic species. Our study was conducted on A. velutinum planted in Berenjestanak(control plots) and Chaibagh(thinned plots) in northern iran in 1991. A randomized sampling method with circular sampling plots of 100 m2was used to measure diameter and height of trees. The results show that the diameter of trees in thinned stands was 19.98 cm and in the control stands 13.84 cm, while the mean heights were 18.33 and 17.46 m, respectively. The mean basal area in thinned stands was 30.74 m2and in the control 15.70 m2per ha. The results of Student’s t tests indicate that there are significant differences at a probability level of 99.9% between the two variously treated stands in diameter(d), height(h), basal area, volume growth and the stability coefficient. We conclude that tending operations with suitable intensity in different time periods are recommended to obtain stable stands.

关键词： Acer velutinum thinning operation afrorestation northern iran

Bark content variations and the production of Populus deltoides as a source of bioenergy under temperate climate conditions

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Journal of Forestry Research 2022年第6期33卷 1807-1815页

作者： Jamshid Eslamdoust Faculty of Natural Resources and Marine Science Tarbiat Modares UniversityTehranIran

Bark biomass as an energy source has a high economic *** content variations and production helps recognize the potential of this bioenergy source spatially before *** percentage of fresh and dry bark in Populus deltoides grown under a monoculture system was examined in the temperate region of northern *** at breast height(DBH)and total height data were analyzed based on an initial *** sample trees were felled,separated into 2 m-segments,and weighted in the field.A 5-cm-thick disc from each segment was extracted for determining fresh and dry bark *** were statistically significantly different in disc diameter classes and decreased with increasing disc *** percentage of the disc classes ranged from 21.8 to 24.4%in small-sized diameters to 8.1-9.3%in large-sized *** differences between fresh and dry bark percentages depended on water content *** power equations were fitted to data of fresh and dry bark percentages and disc diameters as well as *** values of R~2 ranged from 0.89 to *** addition,allometric power equations provided the best fits for relationships between total stem dry biomass,dry bark biomass,and DBH,R~2=0.986 and 0.979 for the total stem dry biomass and stem dry bark biomass,*** allometric models can be used to estimate bark percentage and bark production of *** in segments and for the whole stem for a wide range of segment diameters(8-44 cm)and DBH(15-45 cm).

关键词： Biomass Energy source Forest plantation Eastern cottonwood northern iran