Iranian Journal of Forest and Poplar Research
Year:2015 | Volume:23 | Issue:2|Papers Count:22

In an era of unprecedented industrialization and urbanization, sustainable forest management (including management and conservation measures) are particularly essential. In this context, the criteria and indicators are considered as means for defining, monitoring and assessment of forest sustainability. However, the existing database of research on such criteria and indicators in Iran is still limited. Hence, this study aims at defining a set of criteria and indicators in an example of Kalgachi local system, Chaharmahal-va-Bakhtiari province. This research was performed in several stages using different methods. In the first stage, socio-economic indicators of the Near East Process were prioritized by questionnaires to adapt the regional conditions. The indicators were further compared pair wise using further questioners. In the last step, a set of expert interviews, field studies, local community survey and document reviews in related organizations within the study area were conducted to determine the criteria and indicators. Based on the results, the finally-selected socio-economic indicators based on expert’s opinions and forest-dependent communities included the reduction in the number of interferences to forest areas, improvement of livelihood of forest-dependent communities, cooperation of local communities with equal rights (e.g. in number of groups and man/women share) and cooperation on agricultural development and conditions.

In order to evaluate the amount of poplar wood production in traditional poplar farming, an assessment of annual growth in different stands is necessary. In this study 8 Populus nigra stands along margins of different rivers of Kermanshah province were selected for the analysis. A number of 102 variable sample plots were measured by in a systematic random design. In each sample plot growth attributes were measured. The data was analyzed by one-way analysis of variance and Duncan test. In addition, soil samples were measured and the soil data were analyzed by correlation and PCA analysis. Results showed that the annual growth of 6th stand was three times higher than that of 4th stand, with their cumulated annual ranging between 10.3-38 m3. Furthermore, differences were observed in volume, height and diameter growth amongst the stands. Furthermore, differences were observed in volume, height and diameter growth amongst the stands.The conducted PCA analysis of soil samples showed a marginal significant difference amongst the samples, though no significant correlation between volume growth and soil characteristics was observed. For example decreasing EC and pH improved the volume growth, whereas increasing Clay, N and OC budget led to an increase in volume growth. Compared to the previously achieved results in the literature, the amount of poplar growth seems to be rather a function of management operations in farm rather than the genetic and edaphic attributes.

A variety of new methods have been proposed by ecologists and biologists for data collection on different attributes of coarse woody debris (CWD). Amongst others methods based on probability proportional to size are the newest techniques. These approaches are based on selecting individual logs into the sample unite using some forms of unequal probability sampling. In the present study, we aimed to introduce “Distance Limited Sampling” (DLS) and “Sausage protocol” of “Fixed Area Method” as well as assessing their precision and accuracy for estimating volume of CWD. These methods select individual logs into the samples using probability proportional to length of the logs. To collect the data, a set of attributes including location, top and bottom diameter and length of all logs in a 250×250 m plot in an un-harvested temperate forest were fully inventoried, and the location of logs were mapped. Then different methods with different sample unit sizes were simulated in R programming language environment using SampSurf package. Results indicated that both methods are unbiased. Considering precision of the estimates, Sausage protocol of fixed area sampling led to more precise estimates of volume of the loges than those estimated by DLS. Consequently, Sausage protocol is concluded for further usage as a promising method in the field due to its unbiasedness and production of highly-precise estimates.

This study was carried out to survey the effects of some physical and chemical soil properties on quantitative characteristics of Quercus infectoria. A number of 36 circular sample plots were randomly drawn with each plot being 1000 m2 of size, in which the number of trees, height, diameter and breast height (DBH) and crown diameter of individual trees were measured. The sampling design was a completely randomized design with 12 treatments and 3 replications. In each plot, soil profiles were dug (2 × 1.5 × 1 m), and samples were taken to measure the physiochemical properties. The results of analysis showed significant difference among treatments (p<0.01). Moreover, comparison of quantitative characteristics and physiochemical soil properties using Duncan test showed that the tree properties (number, height, DBH and crown diameter) as well as those of soil samples (depth, moisture saturation, percent of organic matter, phosphorus, potassium, sand and clay) showed comparatively better values across valley bottoms and northern slopes. In contrast, the southern slopes were associated with higher percentages of neutral solutes. Stepwise multiple linear regressions among quantitative tree attributes and soil factors suggested significant positive correlations with soil profile depth, soil moisture saturation, organic matter, phosphorus and potassium, and significant negative correlation with the percentage of neutral solutes. All in all an increase in soil depth, soil moisture saturation, organic carbon, phosphorus and potassium are concluded to led to more favorable conditions for the growth of Q. infectoria, whereas increasing the percentage of neutral solutes led to reduced quantitative tree attributes. Therefore, the studied physiochemical soil properties are concluded to essentially influence the occurrence and distribution of Q. infectoria trees in the study area.

Production of tree seeds is associated with considerable variations within individuals and among years. In this study, individual and annual variation in acorn production of Brant`s oak (Quercus brantii Lindl.) was studied in Darbadam Forest, Kermanshah province during 2009-2011. A number of 40 sample trees were selected by stratified random sampling method, followed by measurement of their quantitative variables.Prior to acorn fall in early September, the number of acorns per tree was determined by crown count method. In addition, acorn density (acorn number/m2 crown area) was calculated to compare the potential of acorn production. The result showed great variability within individuals and among years. Some sample trees had no acorns; meanwhile acorn density was more than 40 in some trees. The weakest and the best acorn production were observed in 2009 (mean acorn density=1.6) and 2010 (mean acorn density=10.7), respectively. The last year of study (2011) showed a moderate condition. Significant differences (P<0.05) were solely observed between acorn density of different diameter classes in 2010. Furthermore, the differences in acorn density amongst trees in similar diameter classes among years were only significant (P<0.01) for medium diameter classes. In conclusion, the results confirmed the effect of inherent tree species capability and the seeding year on acorn production of Brant’s oaks.

Nowadays, nitrogen-fixing tree species are often planted in combination with poplar to provide nutrients, though this can reduce the number of host plants and have a negative impact on soil Frankia population. In order to study the effects of mixed plantation of Caucasian alder (Alnus subcordata) and poplar (Populus deltoides) on Frankia nodulation potential, an experiment was carried out within a randomized block design.Five different mixtures of 17–years old P. deltoides (P) and A. subcordata (A) (100A, 70A30p, 50A50P, 30A70 and 100P) were established in Safrabasteh Poplar Research Station in Guilan province of Iran. The results showed that the presence of alder in mixture with poplar positively affected the diameter at breast height (DBH) and height of poplar trees. Mixed plantations with alder can improve Soil pH and the amount of soil nutrients and organic carbon. Furthermore, foliar nutrient concentrations of poplar trees were higher in mixed plantations than in pure plantations. The results of Frankia population analysis showed significant difference between the soils across different species mixture classes. The highest and lowest levels of Frankia population were observed in the rhizosphere soil of pure alder (49.17 g-1 soil) and pure poplar (0.89 g-1 soil), respectively. The Frankia population was negatively correlated with amounts of available P and K, yet it was positively correlated with pH. In addition, Frankia population showed positive and negative correlations with alder DBH and height, respectively. These results confirmed the effects of plant-host density on the viability and population of Frankia.

In this research, the possibility of application of LiDAR-derived characteristics has been studied for discrimination amongst common hornbeam (Carpinus betulus) and Persian maple (Acer velutinum) trees. LiDAR data of individual sample trees were separated in laser point clouds using their measured center coordinates and crown diameter in the field. In district 1 of Shast-Kolate Education and Research Forest in Gorgan, 80 individual A. velutinum and C. betulus tree samples were selected. The trees were either located in dominant storey or were not overlaid by adjacent tree crowns. Tree heights were measured using Vertex 1V GPS device. Crown diameter was measured in four cardinal directions using Leica Disto lasermeter. Center coordinates of the sample trees were determined using both DGPS and distance/azimuth measurement by Total Station device. Different geometrical and statistical metrics of sample trees were extracted from LiDAR data. The results of discriminant analysis suggested the height standard deviation of laser points over 80% of tree height and crown slope as the selected metrics to differentiate the tree species (accuracy=80.3%). The mean of those two metrics showed larger values for hornbeam than maple. The selected LiDAR metrics were ascribed to represent the shape and height variation of returned crown laser points. It is therefore concluded that geometrical LiDAR-derived attributes could successfully helo by differentiating between the two tested tree species.

This study aimed to 1) investigate the relationship between vegetation cover and physiographic factors and 2) determine the indicator species in ecological groups in a gallery forest of Darreh-Khan river in the south of Urmia, NW Iran. Minimal area method was used to determine the area of sample plots. Based on this, arboreal and herbaceous cover plots were recorded in 400 and 100 m2 plots, respectively. Using the Braun-Blanquet cover-abundance scale, arboreal and herbaceous taxa were recorded respectively in 32 and 50 sample plots centered at 0, 20, 50, 100, and 200 m along transects perpendicular to the river axis on both sides at 200 m intervals. We applied cluster and indicator species analysis in order to determine the ecological groups and indicator species. In addition, non-metric multidimensional scaling (NMS) approach was applied to analyze the relationships between vegetation and physiographic factors in the study area. Cluster analysis divided the herbaceous species into three (northfacing slope, south-facing slope, and near-river) ecological categories. The NMS analysis showed that slope and altitude are among the most influencing environmental variables on the distribution of herbaceous plants in this ecosystem. Examples of the indicator plant species in ecological group I (north-facing slope) included Astragalus persicus, Echinops bithynicus and Silene marschallii, whereas Salvia multicaulis, Onosma sericeum and Aristolochia bottae were amongst the indicator species in ecological group II (south-facing slope). Colchicum szovitsii, Galium spurium and Pimpinella anthriscoides were grouped in the third category (near-river). Moreover, woody taxa were seperated into two ecological groups: near-river (Juglans regia and Pyrus syriaca) and far-from-river (Cerasus microcarpa and Pistacia atlantica).

The spatial patterns of trees in different stages of their life provide important information related to forest regeneration and succession processes. Since competition affects forest structure, understanding competition is important when forest management aims to imitate the dynamics of natural ecosystems. For this purpose, an unmanaged control forest was selected with 26 hectares area. All Chestnut-leaved oak (Quercus castaneifolia) trees with a diameter at breast height (DBH) greater than 7.5 cm were measured, and their Cartesian coordinates were recorded. Based on their DBH, the measured trees were then divided into four classes of small timber, medium timber, large timber and extra-large timber. The univariate and bivariate O- ring statistic were used to investigate the spatial patterns and to examine the intra-specific competition, respectively. Results showed cluster spatial pattern in short distances due to heavy seed and high regeneration frequency, which was later changed to random distribution as distance increased. Moreover, interactions between diameter size classes showed that oak trees with different sizes had different positive (attraction) and negative (repulsion) interactions which occurred at different scales based on the size of trees, influenced by light-demanding, limited seed dispersal and intra-specific competition of oak trees.Since the Chestnut-leaved oak trees showed random distribution, the silvicultural interventions should thus be based on individuals and random single selection to create random spatial patterns in the stand.

Non-timber forest products (NTFPs) play an important role in supporting rural livelihoods and food security. Due to a shortage of productive and arable lands and the resulting poverty, many rural households in northern Zagros forests follow a livelihood strategy which is highly dependent on forest products. This study was conducted to 1) investigate challenges and conflicts of NTFPs utilization, which were tested by participatory appraisal of natural resources in three forested villages in Baneh, Kurdistan province. Qualitative and quantitative methods were used to collect data.Field force analysis was used as a theoretical framework. Interviews, questionnaires, brainstorming and group discussion techniques were used. Value of tree fodder was evaluated by Replacement cost method, whereas direct-cost pricing method was used for other products. Results showed that the main product of harvesting across the study area include oak tree fodder, firewood, Gazou, acorn and Mazooj Gaal. NTFP income of the households’ was estimated to be 8510000 IRR. Moreover, more than 50% of collected NTFPs-related household income was shown to be used for subsistence, and the rest was gained by selling the products. More subsistence income for the villagers comes from tree fodder and firewood. The most important problems with NTFPs harvesting were insufficient rules and administrative facilities, deforestation, overgrazing, drought and weakness of market network. Eventually, the main solutions to those problems towards a framework of an ‘integrated’ approach towards the natural resource management were identified as strengthening the cooperative society, development of market network and marketing service, organizing NTFPs harvesting plans and establishing the small scale agro-food industries in this area.

Using machines such as hydraulic excavator and bulldozer is very common in construction of forest roads, and their costs have a major share from the hourly cost of a road construction project. Therefore, the estimation of production and costs of each apparatus production unit is regarded as a powerful mean for appropriate management and optimum usage of the facilities. In Liashisera district situated in 27th watershed of Amlash, a combination of two machines of hydraulic excavator and bulldozer were used in the road construction due to economic and environmental considerations. Majority of excavation operations were initially carried out by hydraulic excavator, and the bulldozer was used in the final stage to correct the slope and prepare the road bed for pouring sand scattering. The components of daily construction work including useful and useless times, technical and personal delays were assessed by time study technique in various slope categories. The results showed the average of production amounts of two machines in the slope classes of 10-30, 30-50 and 50-70 percent to be 71.23, 61.49 and 87.18 m3/h and 13.31, 20.87 and 12.28 m/h, respectively. Production cost of two machines per useful working hour was shown to be 8267 IRR per m3 and 39325 IRR per m.

Gaps within forest canopy cause changes in the received amount (intensity) and quality (PAR) of incoming light on forest ground. This research was performed in natural gaps of a reserve control compartment at Kelardasht region in Mazandaran, northern Iran and aimed to determine the role of gap size and relative light intensity on soil enzyme activity. Hence, 14 gaps at four size class (<200 m2- 200-300 m2- 300-400 m2 and>400 m2) and four light classes (<8 %- 8-17 %- 17-25% and>25 %) were selected. Soil was sampled at 0-20 cm of top soil in the center of each gap. The results showed significantly different dehydrogenase activity in classes of gap size and light intensity, where its maximum amount was observed in the large gap size (300-400 m2) and at low light intensity (<8%), respectively. Urease activity did not show significant difference within the classes. In addition, relative soil moisture was significantly different across the gap size and light intensity classes, whereas organic matter and Nitrogen did not show to be significant different.

Wild almond (Amygdalus arabica Olivier) is one of the main forest trees with high nonwood values in Zagros Mountains of Iran. The study carried out in Karebass area, Cheharmahal & Bakhtiari province and measured seed production capacity in wild almond across eight crown diameter classes (0.5 to 4 m) at individual level. Five trees were chosen in each crown diameter class randomly at different geographical aspects (mainly north and southwards). All major tree dimensions including cross crown diameters, height, sprouts numbers, diameter of thickest sprout at soil lever as well as the total amount of produced seeds were measured in situ and/or ex situ. The values were checked for normal distribution, and analysis of variance of growth characteristics, seed size and total yield were carried out across different crown classes and geographical aspects. Moreover, the significance of differences was assessed separately using a Duncan multiple range test. The results showed that the diameter of thickest sprouts, shrub height, and total seed yield were highly regulated (99% confidence interval) by crown diameter classes. Potential yearly seed yield in the study site was assessed to be 12.4 tons. The fruit and seed yields have been speculated as the main source of income for local inhabitants.

The spatial distribution analysis of woody plants in arid and semi-arid environments explains their interactions and how they influence one another. This study was aimed to evaluate the intraspecific interactions of Eshnan (Seidlitzia rosmarinus) shrubs across a portion of central Iranian arid lands using different summary statistics including pair correlation g (r), O-ring O (r), nearest neighbor distribution D (r), spherical contact distribution Hs (r) and mark correlation kmm (r) functions. A 160 × 160 m2 plot purely covered by Eshnan was selected in Qehi protected area, Isfahan province. The point map of all 989 Eshnan shrubs was obtained by Trimble R8 differential global positioning system with a positional accuracy of 3 mm ± 0.1 ppm. The observed pattern of shrubs showed significant spatial heterogeneity as compared to inhomogeneous Poisson process (a=0.05). The results of g (r) and O (r) revealed the significant aggregation of Eshnan shrubs up to scale of 3 m (a=0.05). The results of D (r) and Hs (r) also showed maximum distance to nearest shrub to be 6 m. It was additionally shown that the distribution of gap sizes was significantly different from random up to this spatial scale. Finally, kmm (r) for height, mean crown diameter, and crown area indicated the aggregation of Eshnan individuals at all scales. In general, positive interactions were concluded to exist amongst Eshnan shrubs at small scales, and they were aggregated due to their intraspecific facilitation effects in the study area.

To evaluate a number of important traits of wild paistachio (Pistacia atlantica) fruit, this study was conducted in two of of its natural habitats in Kurdistan province, including Mazevanband (Baneh) and Dezli (Sarvabad) during 2007-2008. In each habitat, a total number of 30 uniform trees were selected. From each sample tree, 10 fruit samples each weighting 200 g were taken in late October. The traits were measured in labratory.Analysis of variance (ANOVA) using nested method was followed by Duncan test to compare the means. ANOVA results revealed significant differences (P£0.01) between habitats (Sarvabad and Baneh) across all the studied traits, as well as across trees within each habitat for all traits except fruit size. The average diameter at breast height (D) was 69.7 cm, seedless fruit percentage (SLFP) accounted for 20.83%, the average fruit length (FL) and fruit width (FWi) were 5.41 and 6.33 mm respectively, fruit size (fruit width × length) (FWi×FL) was equivalent to 34.48 mm2, the mean weight of complete fruit (FW), seedless fruit (SLFW), backless fruit (fruit without peel) (BLFW) and seed (SW), were 2.15, 1.46, 1.47 and 0.51 g respectively. In addition, seed weight to fruit weight ratio (SW/FW) was 0.24, and mean percentage of oil content (OC%) was 26.86 %. The average of all studied traits except tree diameter and fruit oil in Baneh was generally more than in Sarvabad. Moreover, the regression analysis of oil content on the other traits as independent variables revealed that the regression coefficient of oil content on backless fruit weight (fruit without skin) (BLFW) and seed weight (SW) were positive and significant (P£0.01), while they were negative and significant (P£0.01) for seedless fruit percentage (SLFP) and seedless fruit weight (SLFW), as well as positive and significant (P£0.05) for ratio of seed weight to fruit weight (SW/FW).Thus, the oil content percentage of trees is concluded to be improved by selection of the individuals featuring higher fruit and seed weights.

So far it is well known that the conversion of degraded rangelands to planted forests through afforestation practices affects soil properties. Therefore, we selected one rangeland and two planted forest area to study the physical and chemical properties of soil in different land uses in Hassanabad region of Sanandaj in Kurdistan province.Physical soil characteristics such as the percentage of water content and soil bulk density were sampled in two-week intervals during 2012 to 2013 at three points in each area. In addition, a set of double rings was conducted to measure infiltration rate at three points within each area. The saturated hydraulic conductivity was computed using the experimental infiltration data. The soil samples for measuring chemical properties (e.g. pH, EC, organic carbon content, phosphorus and total nitrogen) were taken from 3 points in each area at the depth of 20 cm with six repeated measurements. The results showed that converting degraded rangelands to tree plantations has resulted in enhancing the quality of soil physical characteristics, whereas only a portion of the chemical characteristics (organic carbon content, phosphorus and total nitrogen) were positively affected.