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Woody Species Diversity and forest Structure from Lowland to Montane forest in hyrcanian forest Ecoregion

Journal of Mountain Science 2013年第4期10卷 609-620页

作者： Seyed Mohammad JAFARI Shahin ZARRE Seyed Kazem ALAVIPANAH School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranP.O. Box 14155-6455 Tehran Iran School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranTehran Iran Department of Cartography Faculty of Geography University of TehranTehran Iran

Alborz Mountains host Caspian hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity （DIV）, forest structure （（stem density （DEN）, mean basal area （MBA） and mean height class （MHC）） and disturbance （DIS） were explored along 2,4oo m altitudinal gradient in hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest （LoF） to mid- altitude forest （MiF） and montane forest （MoF） in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method （PCQM） with 96 sampling points and 83 vegetation samples by plot method （PM） were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters： DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend

关键词： Alborz Mountains Biodiversity forestMensuration hyrcanian forest Disturbance

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Time consumption,productivity,and cost analysis of skidding in the hyrcanian forest in Iran

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Journal of forestry Research 2012年第4期23卷 691-697页

作者： Rostam Mousavi University of Urmia Faculty of ForestryP.O.Box 165UrmiaIran.

The performance of the skidder Timber jack 450 C was presented in timber skidding of non-coniferous trees in hilly and mountainous conditions. An empirical time study was conducted to evaluate the current skidding system in hyrcanian forest in northern Irma for improving production rate of skidding and finding out the production cost for planning. Based on the identified elements of skidding work phase and 130 recorded cycles, we calculated the models for effective time consumption, total productivity, and unit cost. The validity of the model was tested at 95% confidence interval. The average load volume per cycle was 2.82 m3, average one way skidding distance was 450 m, and the average slope was 18%. The average travel speed of unloaded skidder was 5.8 km.h-1, and the average speed of loaded skidder was 0.1 km.h＂~ higher than the speed of the unloaded ones. The travel speed was pre- dominantly affected by longitudinal slopes and types of strip roads. The average speed of pulling the cable was 1.16 km.h-1, and that of load winching was 0.74 ***. The average outputs in skidding was 10.6 m^-3.h^-1 and the unit cost was 12.1 USS per hour. The time consumption and productivity of skidding depends on distances and slope, number of logs per cycle, volume, log length, etc. However, the influence of variables is not the same.

关键词： Time study skidding skidder cost hyrcanian forest Iran

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Runoff and sediment concentration of different parts of a road in hyrcanian forests

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forestry Studies in China 2013年第2期15卷 144-151页

作者： Majid LOTFALIAN Aidin PARSAKHOO Ataollah KAVIAN Seyed Ataollah HOSSEINI Department of forestry Faculty of Natural Resources Sari Agricultural Sciences and Natural Resources UniversitySari 737 Iran Department of forestry Faculty of Forest Science Gorgan Agricultural Sciences and Natural Resources UniversityGorgan 386 Iran Department of Watershed Management Faculty of Natural Resources Sari Agricultural Sciences and Natural Resources UniversitySari 737 Iran

Road prisms, such as cutslopes, fillslopes and road surfaces, can be important contributors of sediment to streams in forested watersheds. In this study rainfall simulations were carried out on cutslopes, fillslopes, road surfaces and forest grounds in hardwood forests of Lolet and Lat Talar, Iran. Water at intensity of 32.4 mm·h-1 was sprayed from a nozzle onto a square area of 0.48 m2. Runoff was collected by water gauge every 4 min and then runoff and sediment parameters were measured in each plot. Results indicated that on road surfaces, the runoff coefficient was 63.28%. On the cutslopes and fillslopes, the runoff coefficients were 35.14% and 10.23%, respectively. On the forest ground as a control, the runoff coefficient was 5.90%. Runoff volume was 2.73 mL·s^-1 on the road surfaces and 1.52 mL·s^-1 on cutslopes. On fillslopes the runoff volume was 0.44 mL·s^-1 and on the forest ground 0.25 mL·s^-1 The greatest rate of soil loss was found on the cutslope （280.79 g·m-2·h-1）. The total soil loss from the cutslopes was two times higher than that from the road surfaces and six times higher than that from the fillslopes. We conclude that cutslopes can be considered the main source of sediments in our study sites, but the function of road surface as a source of runoff generation is more important.

关键词： runoff soil loss road prism rainfall simulation hyrcanian forest

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How does organic matter affect the physical and mechanical properties of forest soil?

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Journal of forestry Research 2018年第3期29卷 654-659页

作者： Ehsan Abdi Shojaat Babapour Baris Majnounian Ghavamodin Zahedi Amiri Azade Deljouei Department of forestry University of Tehran

Determining the physical and mechanical properties of soil and its behavior for engineering projects is essential for road construction operations. One of the most important principles in forest road construction, which is usually neglected, is to avoid mixing organic matter with road materials during excavation and embankment construction. The current study aimed to assess the influence of organic matter on the physical properties and mechanical behaviors of forest soil and to analyze the relation between the amount of organic matter and the behavior of forest soil as road material. A typical soil sample from the study area was collected beside a newly constructed roadbed. The soil was mixed with different percentages of organic matter（control treatment, 5, 10, and 15% by mass） and different tests including Atterberg limits, standard compaction, and California bearing ratio（CBR） tests were conducted on these different soil mixtures. The results showed that soil plasticity increased linearly with increasing organic *** the organic matter from 0%（control） to 15%resulted in an increase of 11.64% of the plastic limit and 15.22% of the liquid limit after drying at 110 ℃. Also,increasing the organic matter content reduced the soil maximum dry density and increased the optimum moisture content. Increasing the organic matter from 0 to 15% resulted in an increase of 11.0% of the optimum moisture content and a decrease of 0.29 g/cm;of the maximum dry density. Organic matter decreased the CBR, which is used as the index of road strength. Adding 15% organic matter to the soil resulted in a decrease of the CBR from 15.72 to 4.75%. There was a significant difference between the two drying temperatures（60 and 110 ℃） for the same organic matter mixtures with lower water content values after drying at 60 ℃. The results revealed the adverse influence of organic matter on soil engineering properties and showed the importance of organic matter removal before excavation a

关键词： Atterberg limits California bearing ratio hyrcanian forest Organic matter content Soil compaction

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Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran

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Journal of forestry Research 2013年第1期24卷 115-119页

作者： Maryam Asadiyan Seyed Mohammad Hojjati Mohammad reza Pourmajidian Asghar fallah Sari Agricultural Sciences and Natural Resources University Sari-Iran.

Soil inorganic N is one of the most important soil quality indexes, which may be influenced by land-use change. The historical conversion of land-use from native vegetation to agriculture resulted in sharp declines in soil N dynamics. This study was conducted to determine the soil inorganic N concentrations and net N mineralization rate in four common types of land-uses in the mountain forest area in the north of Iran, namely arable land, pine plantation, ash plantation, and beech stand. The soil samples were taken from top mineral soil layer （5 cm） in each site randomly （n=6） during August- September 2010. Beech stand and ash plantation showed significantly higher total nitrogen compared with arable land and pine plantation, while extractable NH4 ＋-N concentration was significantly greater in Beech stand compare to arable soils （p〈0.05）. No significantly difference was found in Net N mineralization, net nitrification and net ammonification rates among different land-uses. Results showed that net N mineralization and ammonification were occurred just in the soil of Ash plantation during the incubation time. Our findings suggested that conversion of hyrcanian forests areas to pine plantation and agricultural land can disrupt soil natural activities and affect extremely soil quality.

关键词： soil quality net N mineralization nitrogen dynamic land use hyrcanian forest Alandan.

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