欧洲鹅耳枥秋冬变色期叶色变化的生理特性研究

以欧洲鹅耳枥1年生幼苗为材料,通过测定10月下旬-12月上旬变色期叶色、色素含量、酶活性、可溶性糖和光合特性的变化,研究其呈色机理。结果表明,欧洲鹅耳枥在秋季变色的主要原因是叶绿色含量下降,类胡萝卜素颜色呈现,且叶绿素和类胡萝卜素含量变化呈极显著正相关（ P＜0.01）;变色期花色素苷与PAL活性、可溶性糖含量一直处于下降趋势,呈正相关,与POD活性、可溶性蛋白的含量呈显著负相关;变色过程中,气孔因素不是导致光合速率下降的主要原因。     

Distribution and tensile strength of Hornbeam (Carpinus betulus) roots growing on slopes of Caspian Forests, Iran

Biomechanical characteristics of the root system of hornbeam (Carpinus betulus) were assessed by measuring Root Area Ratio (RAR) values and tensile strength of root specimens of eight hornbeam trees growing on hilly terrain of Northern Iran. RAR values of the roots were obtained using profile trenching method at soil depth of the top 0.1 m. In total 123 root specimens were analyzed for tensile strength. Results indicate that in general, RAR decreases with depth, following a power function. The RAR values in up and down slopes have no significant statistical differences. In most cases, the maximum RAR values were located in soil depth of the top 0.1 m, with maximum rooting depth at about 0.75 m. The minimum and maximum RAR values along the profiles were 0.004% and 6.431% for down slope and 0.004% and 3.995% for up slope, respectively. The number of roots in the up and down slope trenches was not significantly different. In the same manner as for RAR, number of roots distributing with depth was satisfactorily approximated a power function. The penetration depths of above 90 percent of the roots were at soil depths of 50 cm and 60 cm for up and down slopes, respectively. Results of Spearman’s bivariate correlation showed no significant correlation between the RAR value with tree diameter and gradient of slope and number of roots. The mean value of root tensile strength was 31.51 ± 1.05 MPa and root tensile strength decreased with the increase in root diameter, following a power law equation. Using ANCOVA, we found intraspecies variation of tensile strength. Biography: Ehsan Abdi (1978– ), Male, Ph.D candidate, in the Department of Forestry, University of Tehran, Karaj 31585-3314, Iran.     

Distribution and tensile strength of Hornbeam (Carpinus betulus) roots growing on slopes of Caspian Forests, Iran

Biomechanical characteristics of the root system of hornbeam (Carpinus betulus) were assessed by measuring Root Area Ratio (RAR) values and tensile strength of root specimens of eight hornbeam trees growing on hilly terrain of Northern Iran. RAR values of the roots were obtained using profile trenching method at soil depth of the top 0.1 m. In total 123 root specimens were analyzed for tensile strength. Results indicate that in general, RAR decreases with depth, following a power function. The RAR values in up and down slopes have no significant statistical differences. In most cases, the maximum RAR values were located in soil depth of the top 0.1 m, with maximum rooting depth at about 0.75 m. The minimum and maximum RAR values along the profiles were 0.004% and 6.431% for down slope and 0.004% and 3.995% for up slope, respectively. The number of roots in the up and down slope trenches was not significantly different. In the same manner as for RAR, number of roots distributing with depth was satisfactorily approximated a power function. The penetration depths of above 90 percent of the roots were at soil depths of 50 cm and 60 cm for up and down slopes, respectively. Results of Spearman's bivariate correlation showed no significant correlation between the RAR value with tree diameter and gradient of slope and number of roots. The mean value of root tensile strength was 31.51 ± 1.05 MPa and root tensile strength decreased with the increase in root diameter, following a power law equation. Using ANCOVA, we found intraspecies variation of tensile strength.     

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

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 Iran 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 m 3,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-1 higher than the speed of the unloaded ones.The travel speed was predominantly 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 km·h-1.The average outputs in skidding was 10.6 m 3 ·h-1 and the unit cost was 12.1 US$ 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.     

生长调节剂对欧洲鹅耳枥水培生根的影响

[目的]筛选适合欧洲鹅耳枥水培生根的植物生长调节剂处理方法,并讨论欧洲鹅耳枥水培苗与土培苗的差异,为欧洲鹅耳枥生根机制研究及进一步生理生化研究提供理论基础.[方法]以欧洲鹅耳枥硬枝枝条为试材,研究不同植物生长调节剂种类、质量浓度和处理时间对生根率、愈伤组织率、存活率、平均根数、平均根长、皮部生根枝条率、皮部平均根数、切...     

Effects of forest harvesting on runoff and sediment characteristics in the Hyrcanian forests,northern Iran

Loss of canopy cover by forest harvesting generally increases the average surface runoff volume and sediment. Selective cutting (single and group selection method) is the most usual forest harvesting method in the Hyrcanian forests in the north of Iran. The purpose of this study is to find the effect of selective logging technique on the hydrological behavior of runoff and sediment in the Kheyrud forests located in northern Iran over 1 year. Four treatments were implemented: natural forest without harvesting (C), forest with selective harvesting (H) and area without canopy cover (WC) and skid trail (S). Three types of data were measured in each plot including soil chemical and physical properties, runoff and sediment load after each rainfall. The results indicate significant differences (P ≤ 0.05) in runoff generation and sediment production with respect to the treatments cover. The runoff in all treatments showed relatively similar response to rainfall, while the highest runoff and sediment were observed in skid trails, and the area without canopy cover (1.13 and 0.62 mm, and 1.2 and 0.51 g m^?2), averagely. In contrast, the natural forest without harvesting and the forest with selective harvesting treatments exhibited the lowest amounts of runoff (0.2 and 0.44 mm) and sediment (0.1 and 0.17 g m^?2), averagely. Implementation of low logging technique was useful to control the effects of logging on the runoff and sediment yield.     

Effect of site and elevation on wood density and shrinkage and their relationships in Carpinus betulus

This study examined the effect of site and elevation on the oven-dry density and volumetric shrinkage of hornbeam (Carpinus betulus) wood.For this purpose,45 normal hornbeam trees from three different sites (Mazandaran,Guilan and Golestan) at three elevations,300 m (low elevation),700 m (intermediate elevation) and 1100 m (high elevation) from natural forest in northern Iran were selected.Disks were cut at breast height from mature wood and test samples were prepared to determine physical properties,i.e.,wood density and volumetric shrinkage.The results show that there are significant differences between site and elevation on these physical properties of wood.The interaction effects between site × elevation on wood density and volumetric shrinkage were also statistically significant.At any fixed site,wood density and volumetric shrinkage increased with elevation.As well,their values at Guilan were higher than those at the other two sites.The relationship between wood density and volumetric shrinkage was determined by simple regression equations.Strong,positive relationships between wood density and volumetric shrinkage at each site were found.Again,these were stronger at the Guilan site than at the other two sites.Given a fixed site,the correlation at high elevation was stronger than at the other two elevations.     

Effect of acetylation on the chemical composition of hornbeam (Carpinus betulus L.) in relation with the physical and mechanical properties

Common hornbeam (Carpinus betulus L.) is a highly underused wood species despite its great hardness, strength, wear-resistance and toughness. It is mainly used as firewood in Hungary because of its wood defects, irregular shape and low-dimensional stability. These wood defects and small breast height diameter result in a low yield. It is non-durable outdoors as it tends to turn grey, crack and be attacked by wood-decaying organisms. Indoors it lasts for hundreds of years. One technology that could improve the stability and durability properties is acetylation. Hornbeam was acetylated with the Accoya® method under industrial conditions. The aim of this research was the assessment of acetylation affecting the chemical properties of hornbeam wood and how these are related to the change in physical and mechanical properties. Main wood constituents (cellulose, hemicellulose, Klason lignin, extractives and ash content) were determined and compared. Chemical parameters related to the degradation of structural polymers were also evaluated (total phenolic and soluble carbohydrate contents, pH and buffering capacity, furfural, levulinic acid, formic acid, acetic acid). Structural changes in acetylated wood and in the Klason lignin fraction were also assessed using FTIR spectroscopy.     

盐胁迫对鹅耳枥幼苗光合作用和荧光特性的影响

应用盆栽试验研究了不同浓度NaCl胁迫下欧洲鹅耳枥和鹅耳枥2年生幼苗光合作用及叶绿素荧光特性的变化。结果表明:随着盐胁迫的加剧,两种鹅耳枥叶绿素总量呈先升后降的趋势,且鹅耳枥叶绿素总量高于欧洲鹅耳枥;叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾作用(Tr)随着盐胁迫的加剧均显著降低,而气孔导度(Gs)则呈上升趋势;高盐浓度下鹅耳枥Pn和Gs的下降幅度比欧洲鹅耳枥小,Tr则明显高于欧洲鹅耳枥,Ci变化幅度较小。光化学量子效率(ΦPSII)、最大光化学效率(Fv/Fm)、电子传递速率(vETR)、光化学猝灭参数(qP)值随着盐浓度的增加总体呈下降趋势,鹅耳枥ΦPSII和Fv/Fm下降趋势较为缓慢,qP下降幅度小于欧洲鹅耳枥。鹅耳枥生长受盐胁迫的干扰程度小于欧洲鹅耳枥,其净光合速率下降幅度相对较小,光合作用受胁迫的程度小于欧洲鹅耳枥。     

The effect of single-tree selction system on soil properties in an oriental beech stand of Hyrcanian forest,north of Iran

A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small (60 150 m 2 ), medium (151 241 m 2 ), large (242 332 m 2 ) and very large (333 550 m 2 ) gaps, as well as under closed stands were studied eight years after the gap creation. Soil samples were taken from three depths, 0 10, 10 20 and 20 30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters: Mg +2 concentration of 0 10 cm at medium gap size, bulk density of 10 20 cm at very large gap size as well as K + and Ca +2 concentrations at 20 30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent (Sp %) at 0 10cm as well as P and Mg +2 at 20 30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10 20 cm. Significant differences were observed between gaps andclosed canopy regarding P and Ca +2 at depth 0 10 cm and 10 20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region.     

伞伐更新法对赫卡尼亚(Hyrcanian)森林系统中森林再生和林分结构的影响

研究伞伐更新法对赫卡尼亚森林系统中森林再生和林分结构的影响。在伊朗北部优势种为山毛榉（Fagus orientalisLipsky）的硬木林,采取伞伐更新法和非伞伐更新法方法设计实验区。结果表明,在山毛榉（F orientalis Lipsky）林中采用伞伐更新法处理,明显影响林下草本植物种的频度和密度。伞伐更新法处理后,林堇菜（Viola silvestris Lam.）、车叶草（Asperula odorata L.）、苔草（Carex spp.）和悬钩子（Rubushyrcanus Juz）的种频度明显增加。在对照区,树种的胸高直径（57.50±2.15cm）大于被处理区（50.67±1.88cm）的树种的胸高直径（50.67±1.88 cm）,但对照区和处理区的树种的高度值相似。在1995-2005年间,波斯铁木（Parrotia persica）苗木数量增加到13.2%,而山毛榉（F orientalis）和欧洲鹅耳枥（Carpinus betulus）的苗木数量却明显减少。总之,应该利用其它育林方法,如,带状择伐作业,而不是伞伐更新法培育赫卡尼亚森林中山毛榉林。     

Pollen morphology and trichome types of Betula spp. in the Hyrcanian forests of northern Iran

Pollen and trichome morphology of the genus Betula were evaluated from three main habitats in Iran using light and electron microscopy.Pollen types were identical and tri-porate;however,in terms of quantitative data,some differences were observed in exine(outside)wall thickness,length of polar axis and length of equatorial axis,possibly due to the environment.Pollen alone is insufficient to separate species of Iranian birch.Investigation of the trichome trait(small hairs or other outgrowths)revealed that birch species in Iran belong to:(1)Betula litwinowii Doluch.according to the low density of trichomes on the adaxial surface of the leaves and the lack of trichomes on the abaxial surface and many trichomes on the petioles;(2)Betula pendula Roth.due to the absence of trichomes on the adaxial surface and the low density of trichomes on the abaxial surface;and,(3)in the adaxial and abaxial surfaces of leaves and petioles,the trichomes had different types of pilose(long,soft hairs),and this strengthens the possibility of a different species or more likely a hybrid of B.pendula.     

A floristic survey of the Hyrcanian forests in Northern Iran,using two lowland-mountain transects

We investigated the floristic composition of the Hyrcanian forests and the related forest-steppe ecotone in Northern Iran by using two long ecological transects, from lowland to upper mountain areas. The study was conducted during 2008 and 2009 and yielded the identification of 395 plant taxa belonging to 233 genera and 78 families. Dicots with 300 taxa were the richest groups of the flora, followed by monocots with 75 taxa, pteridophytes with 18 species,and gymnosperms with two species. The largest families were Asteraceae(33 taxa); Rosaceae(32 taxa); and Poaceae(30 taxa), and the most diverse genera included Carex(15 taxa); Alchemilla(7 taxa); and Poa, Geranium and Acer(6 taxa each). Hemicryptophytes were the most dominant life forms in the area(40 %); followed by geophytes(31.4 %); phanerophytes(15.4 %); therophytes(11.4 %); and chamaephytes(1.8 %). Phytogeographically,Euro-Siberian/Irano-Turanian elements(86 taxa, 21.8 %)and Euro-Siberian elements(85 taxa, 21.5 %) were the most common chorotypes in the area. Out of 395 taxa, 66taxa(16.7 %) were endemics and subendemics in Iran, of which 26 taxa were exclusively endemics of Iran.According to the IUCN Red List Categories, 48 threatened plant taxa were found in the study area. Plant diversity, life form, and chorotypes in the current study were compared with similar transect studies in other areas of the Hyrcanian forests and in different altitudinal belts, using S?renson similarity indices. Floristic composition of the surveyed transects demonstrated almost 50 % similarity between them.     

Wild pistachio tree (Pistacia mutica) in the Qalajeh forest region of western Iran

Wild pistachio tree (Pistacia mutica) is considered the most important species in the Zagros forests. It can adapt to unfavorable environmental conditions. To find the suitable ecological conditions for pistachio species, we investigated different environmental factors such as gradient, aspect and position of the slopes through the distribution area. Frequency of pistachio trees in the north and northwest of Qalajeh forests was 36.4% and 1%, respectively. Maximum (32%) and minimum (13%) number of wild pistachio trees were in 30%–60% and >120% slope classes, respectively. The most number and least number of pistachio trees were found at elevations of 1100–1200 m and 2200–2300 m, respectively. The percentage of pistachio canopy coverage was 10. The average percentage of herbaceous coverage was 6.5. Pistachio trees of diameter per hectare at breast height (DBH) >20 cm numbered 5 while average number of pistachio trees was 8 per hectare. Pistachio seedlings per hectare averaged 3.5. The number of other species per ha was 7 trees. The effect of aspect on other species was not significant (p=0.151). Slope class and geographical aspect did not affect regeneration (p=0.275 and p=0.111, respectively). Pistachio plays an important economic role in semi-arid areas, therefore it is essential to protect and restore Qalajeh forests through participation by government and local people.     

Earthworm population and microbial activity temporal dynamics in a Caspian Hyrcanian mixed forest

Few studies have analyzed how tree species within a mixed natural forest affect the dynamics of soil chemical properties and soil biological activity. This study examines seasonal changes in earthworm populations and microbial respiration under several forest species (Carpinus betulus, Ulmus minor, Pterocarya fraxinifolia, Alnus glutinosa, Populus caspica and Quercus castaneifolia) in a temperate mixed forest situated in northern Iran. Soil samplings were taken under six individual tree species (n = 5) in April, June, August and October (a total of 30 trees each month) to examine seasonal variability in soil chemical properties and soil biological activity. Earthworm density/biomass varied seasonally but not significantly between tree species. Maximum values were found in spring (10.04 m^?2/16.06 mg m^?2) and autumn (9.7 m^?2/16.98 mg m^?2) and minimum in the summer (0.43 m^?2/1.26 mg m^?2). Soil microbial respiration did not differ between tree species and showed similar temporal trends in all soils under different tree species. In contrast to earthworm activity, maximum microbial activity was measured in summer (0.44 mg CO₂–C g soil^?1 day^?1) and minimum in winter (0.24 mg CO₂–C g soil^?1 day^?1). This study shows that although tree species affected soil chemical properties (pH, organic C, total N content of mineral soils), earthworm density/biomass and microbial respiration are not affected by tree species but are controlled by tree activity and climate with strong seasonal dynamics in this temperate forest.     

Chemical content and seasonal variation of throughfall and litterflow under individual trees in the Hyrcanian forests of Iran

We assessed the effect of seasons and the tree species velvet maple (Acer velutinum Boiss), Hainbuche hornbeam (Carpinus betulus L.) and chestnut-leaved oak (Quercus castanefolia C. A. Mey.; Fagaceae) on nutrient fluxes (Na⁺, K⁺ and Ca²⁺) in throughfall (TF) and litter flow (LF) from January 2012 to February 2013. Potassium (K⁺) and calcium (Ca²⁺) in total TF and LF over the measurement period significantly differed between 3 the species (p < 0.05). Maple and oak trees had significantly higher fluxes of K⁺ and Ca²⁺ in their TF, respectively. The average quantity of nutrients in LF was significantly higher in the leafy season than in the leafless season for all cations except for Na⁺. Under velvet maple trees, the average flux of nutrients (Na⁺, K⁺, and Ca²⁺) in TF was significantly higher than LF. Lastly, leaching of potassium (K⁺) and calcium (Ca²⁺) in LF during the measurement period was significantly lower than TF under the hornbeam trees. Our results suggest that different tree species may impact the nutrient availability and possibly the sustainability of Hyrcanian forests. Further research is needed to determine how managing different species will affect the long-term nutrient status of these forests.     

Traditional mule logging method in Hyrcanian Forest: a study of the impact on forest stand and soil

We inventoried plant regeneration and soil compaction along mule trails to evaluate damage to forest stands and regeneration follow-ing mule hauling before and after operations in Kheyrud Forest in the...     

Erratum to: Wild pistachio tree (Pistacia mutica) in the Qalajeh forest region of western Iran

<正>Erratum to:Journal of Forestry Reasearch,(2013)24(3):611-614DOI10.1007/s11676-013-0393-2The original version of this article unfortunately contained one mistake in author name in the footnote.The second author's name,"Mousa Rasouli",actually should be Hamid Soofi Mariv.The corrected version of the footnote should be as the following:     

Time consumption, productivity, and cost analysis of the motor manual tree felling and processing in the Hyrcanian Forest in Iran

An empirical time study was conducted to evaluate the per- formance of the current felling and tree processing methods used in Northern Iran’s Hyrcanian forest. Motor-manual felling is done mostly in winter, while tree processing starts when the felling season ends. We identified the elements of felling and processing work phases, and 142 cycles and 110 cycles were respectively recorded for felling and proc- essing. On the basis of data analysis (time study), we developed statisti- cal models of effective time consumption in the respective work phase and for its total productivity. The production rate of felling with and without delay time was 9.7 and 11.65 trees per hour (0.17 USD·m -3 and 0.21 USD·m -3 ), and the average production cost with and without delay was 1.21 USD and 1.45 USD per tree, respectively. The average produc- tivity of processing was 35 m 3 per effective hour and the average unit cost of processing was 0.22 USD·m -3 .     

The impact of road disturbance on vegetation and soil properties in a beech stand,Hyrcanian forest

The ‘road-effect zone’ is a concept developed to describe the impact of road construction on the surrounding area. Although many aspects of the road-effect zone have been investigated, the road-effect zone on soil properties (pH, bulk density, soil moisture, electrical conductivity, organic matter (%), C (%), total N (%), available Na, Ca, Mg, P, and K), light regimes (leaf area index and canopy cover), and a Raunkiaer’s life-form classification of plants remains poorly understood, especially in oriental beech (Fagus orientalis Lipsky) forests. Hence, the main aims of this research were to estimate the extent of the road-effect zone and to identify the main environmental changes due to forest roads. Specifically, we aimed to evaluate road-effects on: (1) the composition of herbaceous species and tree regeneration (up to 100 m distance from the forest road); (2) the light regime; and (3) soil properties, potentially related to changes in ecosystem functions and composition. We observed that forest roads can have significant impacts on soil, stand characteristics, and vegetation composition. The estimated road-effect zone extended up to 30 m from the road edge. Landscape planners should be aware that road-effect zones can potentially influence the ecology and environmental conditions of an area up to 30 m from the road edge.