Effective factors on ecological capability in the northern forest of Iran

Proper programming and multiple use of environment are based on evaluation of the potential of land. Understanding of land capabilities in forests and their classifications can facilitate programming. Site capability classification is based on the understanding of environmental and ecological specifications. In fact ecological land classification is a system that classifies regions or sites with relative homogeneity in variables or ecological resources.  Aim of this research is ecological evaluation of capability in forest sites of Nav-Asalem, Lesakooti-Tonekabon and Ziarat-Gorgan, in the Caspian region. The studied sites were selected by on the bases of following criteria: elevation, dominance aspect, level of intervention and availability of primary data. After exploration of ecological resources, analyze of them by (GIS) and data ultimately, the map of homogeneous ecological unites was prepared. Evaluation of ecological capability of the sites was performanced by multi-factor method and Makhdoom model. Finally, the forest site capability was demonstrated in 7 capability classes and their maps were prepared. The results showed that slope percentage, elevation and vegetation density factors are effective factors which are common factors in all models. Distinctive components of specific models are depth of soil at specific model of Nav-Asalem forest, the type of parental material and soil evolution at the specific model of Lesakooti-Tonekabon forest and depth of soil and soil evolution at the specific model of Ziarat-Gorgan forest

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

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

Qualitative and quantitative investigation of Juniperus-Cotoneaster forest reserve in Ooshan (Central Alborz, Iran)

Juniperus-Cotoneaster reserve of Ooshan located in central Alborz (north of Iran), is one of the Irano-Turanian forest stands which shows the characteristics of a semi-virgin ecosystem. Although the stand has registered as a "forest reserve" by Forest and Rangeland organization of Iran, some evidences of deforestation and changing the landuse are obvious. The aim of this research was identification and study of biologic and ecologic characteristics of the stand to provide the situation of subsequent studies as a first step for further investigations. Data obtained using stratification method by one strip transect in each stratum. After analysis of the data, structural and ecological characteristics and healthiness of the stand were considered. In this stand, Cotoneaster kotschyi isthe dominant species with a frequency of 51%. Juniperus excelsa with a frequency of 10% and 6.5 meter heightis the dominant species of the tree layer. According to the abundance of species, two forest types were distinguished in this stand: Cotoneaster kotschyi-Juniperus excelsa and Cotoneaster kotschyi-Cerasus microcarpa. Species in the tree storey were Juniperus excelsa, Lonicera nummularifolia, Pistacia atlantica and Celtis caucasica whilespecies in shrub storey were Cotoneaster kotschyi, Cotoneaster nummularioides, Cerasus microcarpa, Rosa spp., Rhamnus pallasii, Colutea persica and Berberis spp.. The structure of the stand is uneven-aged and irregular. Regeneration in the areas with closed canopy is 7 times more than the areas with sparse canopy. The healthiness of stand was considered by ranking to main 7 species

Effect of physiography on asexual reproduction of Iron wood (C‍ase study: Kheiroud forest)

Iron wood (Parrotia persica) is one of the endemic species in the Hyrcanian forests that grows naturally in the northern forests of Iran. This species is reproduced through asexual reproduction using coppice shoot. In order to determine the effect of altitude on asexual regeneration of Ironwood, Kheiroud experimental forest was selected. The altitude was categorized in the groups of 1) less than 400 m, 2) 400-800 m and 3) 800-1200 m.a.s.l. The coppice shoots were also divided into two groups of a) dbh 5 cm. 90 circle plots, each 1000 m2, were laid out in the study area. Analyze of variance and Duncan’s test were used to compare the number of coppice shoots among and between the groups. Results showed that the maximum total number of coppice shoots (10.3/tree) was counted in the lower altitude group (400 m.a.s.l.) while, the maximum number of coppice shoots with dbh >5 cm (3.5/tree) was counted in higher elevations (800-1200 m.a.s.l.). The differences between groups were statistically significant. In general, producing of coppice shoots shows an inverse relation with increasing of altitude. This study suggests that silvicultural interventions should be more focused in lower elevations

Comparison of seedling and coppice regeneration in pruned and undisturbed oak forests of Northern Zagros (Case study: Baneh, Kurdistan province)

Regeneration and forest durability guarantee is one of the most important aspects of forest sustainability and it should be placed in forest plans priority. So, due to important role of Zagros forests, comprehensive investigation about regeneration crisis becomes an increasing necessity. In this study we tried to investigate on seedling and coppice regeneration in two categories of higher and lower than 2 meters height classes and in untouched and traditionally pruned stands in three regions with different disturbance regimes. Study sites were located at Armardeh in Baneh city (Northern Zagros, Iran). Results of the study state that seedling and coppice regeneration in lower than 2 meters height classes are significantly more in untouched forest stands, and its density in site number "1" to "3" is 3250 versus 375± 92, 1600 versus 130± 18 and 310 versus 81± 37 per sample plot (2500 m2), respectively. In untouched stands in site number "1" and "2" saplings in higher than 2 meters height classes are 533 and 66 per sample plot., respectively, but in untouched stand in site number "3", due to livestock grazing, there is no sapling higher than 2 meters like other pruned stands. According to our results the most important factors affecting oak regeneration in this region are livestock grazing, fire, acorn collecting by villagers for domestic fodder, summer drought, pests and diseases on acorns and seedlings

Qualitative investigation of Gall Oak (Quercus infectoria Oliv.) acorns in untouched and pruned forest stands of Baneh (Kurdistan province, N-W Iran)

Due to encroachment and intense utilization, natural ecosystems of Zagros lost their normal trend and have converted to fragile and sensitive ecosystems. There are dense human populations that live in these forests which are depended on these forest resources. One of the most important utilizations in northern Zagros is Galazani (pruning) and using of oak limbs as fodder. This kind of use leads to prominent changes in forest structure and its physiognomy in some region (for example Alot in Kurdistan province) which can be a hazard for forest sustainability. Regarding to this problem and having no regeneration from seed, qualitative characteristics of Gall oak acorns, that is one of the most prominent species in these forests, was investigated in three untouched and pruned sites. Totally 60 Gall-oak trees (10 trees per site) and 6000 acorns (100 acorns per tree) were collected. Primary moisture of acorns in untouched sites was a little more than in pruned sites but there was no significant difference between them. The weevil Curculiogladium and Balaninusgladium were the insect species that predated the acorns collected from our sites. There were significant difference (in level of 95%) in the infestation rate among untouched and pruned sites of Blake, however in Ghole-shir and Mir-Yousef sites were no significant differences between insect-infested acorns. The weight of thousand acorns was significantly more in untouched sites; probably because of having more time to storing enough nutrients in their cotyledons. Germination percent and germination index data were analyzed by simple One Way ANOVA, and their averages were compared by Duncan test. There were no significant differences between germination percent of untouched and pruned sites. Comparing means indicate that, Blake site with 96.75 germination percent was placed in group A, Ghole-shir and Mir-Yousef sites were placed in group B with 90.78 and 88.75 germination percent, respectively. Germination index of untouched and pruned sites had no significant differences and in Duncan grouping they placed in one group. The values for germination index in Mir-Yousef, Blake and Ghole-shir sites were 13.18, 12.83 and 12.36, respectively

Morphological Leaf characteristics of Persian walnut (Juglans regia L.) in Iranian population

Genetic resources are the most valuable national treasure of a country and it is vital to identify, conserve and use them. The Persian walnut (Juglans regia L.) is one of the most valuable genetic resource in Iran due to its multi benefits (nutrition, wood, environment conservation, genetics and medicine). For this reason, 32 leaf morphological characteristics of J. regia were studied on nine populations (four native and five cultivated) and 243 individual trees. Leaf sampling was made two years for the native populations and one year for the cultivated populations. The effects of year variation on leaf characteristics and the effects of leaflet numbers on wealth variation of the characteristics within each genotype were studied. The ANOVA analysis showed that there were significant differences between the walnut genotypes in respect to their leaf characteristics (

Investigation on the concept of control in forest management plans of Caspian forests (Case study: Kheyrud forest)

At the time being, in the Caspian forests two functions of wood production and forest conservation are of the great significance, but in course of time passage, it is needed to express processes concepts of planning, implementation and control of forest management plan in a innovative expression. This study tries to make an object-oriented planning and logical framework approach as performance tool on forest management plans (case study: Kheyrud) from stand point of wood production and forest conservation, design target system in a log frame and control of forest activities step by step. The results of the study express two aspects of control concept to achieve objectives (control of success) and activities (control of activities). This expression means a new concept of control in the Caspian forest management plans

Natural regeneration of tree species in ralation to gap charactristics in natural beech (Fagus orientalis Lipsky) stand, north of Iran

- امان‌زاده، ب.، امانی، م.، امین‌املشی، م. و صالحی، م.، 1385. بررسی زادآوری راش در روشنه‌های طبیعی جنگلهای اسالم. پژوهش وسازندگی، 71: 25-19. - حبیب‌پور گتابی، ک. و صفری شالی، ر.، 1388. راهنمای جامع کاربرد SPSS در تحقیقات پیمایشی. انتشارات متفکران، چاپ دوم، 860 صفحه. - حجتی، س.م.، 1378. بررسی نحوه پراکنش و ساختار سنی تجدید حیات طبیعی گونه راش در راشستان‌های بخش گرازبن جنگل خیرودکنار- نوشهر. پایان‌نامه کارشناسی ارشد، دانشکده منابع طبیعی دانشگاه تهران، 67 صفحه. - دلفان اباذری، ب.، ثاقب‌طالبی، خ. و نمیرانیان، م.، 1383. بررسی سطوح روشنه‌های زادآوری بر وضعیت کمی نهالهای استقرار یافته در قطعه شاهد جنگلهای کلاردشت طرح لنگا. فصلنامه تحقیقات جنگل و صنوبر ایران، 12 (2): 266-251. - زبیری، م.، 1384. آمار و اندازه‌گیری جنگل. انتشارات دانشگاه تهران، چاپ دوم، 400 صفحه. - گودرزی، غ.، 1375. بررسی وضعیت زادآوری راش در بخش 2 طرح جنگلداری لیوان و بنفشه‌تپه. پایان‌نامه کارشناسی ارشد، گروه جنگل‌داری و اقتصاد جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، 78 صفحه. - مرتضی‌پور، ص.، مهاجر، م.ر.، ثاقب‌طالبی، خ. و زاهدی، ق.، 1384. بررسی رابطه زادآوری درخت راش با شکل زمین. تحقیقات جنگل و صنوبر ایران، 13 (4): 474-447. - مروی مهاجر، م.ر.، 1376. جزوه جنگل‌شناسی تکمیلی. دانشکده منابع طبیعی دانشگاه تهران، 55 صفحه. - مروی مهاجر، م.ر، 1385. جنگل‌شناسی و پرورش جنگل. انتشارات دانشگاه تهران، چاپ دوم، 387 صفحه. - موسوی میرکلایی، س.ر، ثاقب‌طالبی، خ.، طبری، م. و پورمجیدیان، م.ر.، 1382. تعیین اندازه سطح حفره تاج‌پوشش برای بهبود زادآوری راش. مجله منابع طبیعی ایران، نشریه دانشکده منابع طبیعی دانشگاه تهران، 56 (1و2): 46-39. - مهربان‌فر، ز.، 1388. مقایسه غنا و نوع گونه‌های درختی با ابعاد مختلف قطعه نمونه (مطالعه موردی: بخش گرازبن جنگل آموزشی و پژوهشی خیرود). سمینار کارشناسی ارشد، دانشکده منابع طبیعی دانشگاه تهران، 35 صفحه. - Adeniji, B.A., Kahissai, K.T. and Kisingo, A.W. 2004. Impact of gap size on tree species regeneration in different location in Kibale forest. Plant and Forest Ecology, 86: 217-227. - Brokaw, N.V.L., 1982. The definition of treefall gap and its effect on measures of forest dynamics. Biotropica, 11: 158-162. - Diaci, J., Pisek, R. and Boncina, A., 2005. Regeneration in experimental gaps of subalpine Picea abies forest in the Slovenian Alps. European Journal of Forest Research, 124: 29-36. - Dobrowolska, D. and Veblen, T.T., 2008. Treefall-gap structure and regeneration in mixed Abies alba stands in central Poland. Forest Ecology and Management, 255: 3469-3476. - Gagnon, J.L., Jokela, E.J., Moser, W.K. and Huber, D.A., 2004. Characteristic of gaps and natural regeneration in mature longleaf pine flatwood ecosystems. Forest Ecology and Management, 187: 373-380. - Huth, F. and Wagner, S., 2006. Gap structure and establishment of Silver birch regeneration (Betula pendula Roth.) in Norway spruce stands (Picea abies L. Karst.). Forest Ecology and Management, 229: 314-324. - Lertzman, K.P. and Krebs, C.J., 1991. Gap-phase structure of a subalpine old growth forest,Canadian Journal of Forest Research, 21: 1730-1741. - Liu, Q. and Hytteborn, H., 1991. Gap structure, disturbance and regeneration in a primeval Picea abies forest. Journal of Vegeteation Science, 2: 391-402. - Martins, S.V. and Rodrigues, R.R., 2002. Gap-phase regeneration in a semideciduous mesophytic forest, south-eastern Brazil.Plant Ecology, 3: 1-12. - Myers, G.P., Newton, A.C. and Melgarejo, O., 2000. The influence of canopy size on natural regeneration of Brazil nut (Bertholletia excelsa) in Bolivia. Forest Ecology and Management, 127: 119-128. - Pedersen, B.S. and Howard, J.L., 2004. The influence of canopy gaps on overstory tree and forest growth rates in a mature mixed-age, mixed-species forest. Forest Ecology and Management, 196: 351-366. - Runkle, J.R., 1981. Gap regeneration in some old-growth forests of the eastern United States. Ecology, 62: 1041-1051. - Yamamoto, S., 2000. Forest gap dynamic and tree regeneration. Journal of Forest Research, 5: 223-229. Nowadays the investigation and identification of natural process such as succession and gaps existence in forest ecosystems have been considered extently in forests management programs. This study examined the regeneration of tree species in relation to size, shape, slope gradient and direction of gaps in a Fagetum community in Gorazbon district of Kheyrud Forest, northern Iran. Three sample area, each 25 ha, were selected and after field study, all gaps within the compartments 317, 318 and 319 were identified. Regeneration of all tree species were record in the gaps, using 100% inventory. Beech, maple, hornbeam and elm tree, were observed in all of the studied gaps, but no significant differences were observed between regeneration frequencies of the species in different gap sizes. The most frequent species were observed in elliptical-shaped gaps. The most frequency of regenerations of beech and maple were observed in slop classes of 11-20%. Also, regeneration of beech, maple, hornbeam and elm showed more frequency in southwest-facing gaps rather than the other directions. According to total number of regeneration in gaps located on the slopes, beech regeneration showed the best establishment rather than another species. Maple and hornbeam followed beech in next ranks

Evaluation of Juniper trees (Juniperus polycarpos C. Koch) radial growth in three sites of Iran by using dendrochronology

By comparing the pattern of narrow and width rings among the trees in one area, the exact year of each rings could be determine. This is the base of Dendrochronology. In this study, according to the important role of Juniper (Juniperus polycarpos) trees, an investigation have been done on variation of tree rings in three sites of Iran; Lain (Khorasan), Firouzkouh (Tehran) and Zanjan. 15 trees have been cored in each sites and ring width of each core was measured. After crossdating and standardization, 3 ring width chronologies were prepared and compared with climate data. Lain's trees were older than the others and Zanjan was the worst site. In many cases, the chronologies had similarities, especially between Lain and Zanjan and in extreme years like 1902, 1917, 1961 and 1975. There were significant correlations between tree ring width and temperature and precipitation in the study areas. Some of the most important ones were the positive effect of precipitation during autumn and winter period before and during the current growing season. The temperature had mostly negative effect on juniper trees but the temperature during September had mostly positive effect concerning the improvement of latewood cell’s expansion. The results showed that the Juniper trees are appropriate trees in Iran for studying dendroclimatology