NATURAL ECOSYSTEMS OF IRAN
Year:2012 | Volume:3 | Issue:1|Papers Count:9

Snags are the main component of forest ecosystems and have important role in sustainability of natural forests. In this research effect of selection method on quantity (number, diameter, height and volume) and quality (species, decay intensity, number and position of cavities) of snags (standing dead trees) were studied in district 1 from Nav Asalem forest in Guilan province. For this reason two parcels (logged and unlogged) were selected and systematic sampling design was used to collection of data. The results showed the size (diameter, height and volume) and frequency (number and volume per hectare) of snags in the logged parcel were lower than unlogged parcel (P<0.01). Ratio of snags volume to stand volume in logged and unlogged parcels were 1.31±0.23 and 4.1±1.16 percent (P<0.01). The snags were compounded more number of species, decay intensity and number of cavities in logged parcel. The height of cavities from ground level was higher in logged parcel than unlogged parcel. Increasing rotation length and remaining different species of live large trees can be positive influence on biodiversity and sustainability in these forests.

The diameter increments are compared between natural and touched native oak stands located in Shive miran forest in Sardasht. For this purpose, sampling designed the randomized-systematic method with rectangular plots that were 30×40 meters in the 40×50 Net. The diameter at breast height and height of individual trees were measured. The Point Quarter method was then utilized to measure the diameter increment for the period of interest and 61 diameter increments in each stand were collected. The means of different between diameters Growth in the two areas were calculated by Kolmogorov-Smirnov (test of normality), Chi-Square (normality of diameter distributions), ANOVA (compere of diameter growth in the diameter classes) and Mann-whitney (compere of diameter growth in the two stands) test. To analysis data SPSS18 software. Results showed that the mean annual diameter increments for both stands are respectively 3.47 and 2.73 millimeters. Densities are 246 and 162 trees per hectare for natural and touched stand. The differences between diameters Growth in the two areas were statistically significant. The comparison of the parameters for both stands, suggest that there are highly significant differences between natural and touched stand and mean of diameters Growth in the natural stand higher the touched stands.

This study aimed to introduce vascular plants species composition in Perk forest with about 2920 ha area and located at 35 km of Khoramabad. The results showed that there are 145 species belonging to 110 genus and 32 families in this area. The most recognized species belong to Compositae family with 24 species, 16.55% of total species. Chorological study showed that the most acquired plant species is belonged to the Irano-Turanian floral elements. The results also showed that there are 19 threatened species, 13.1% of total species, in this area. Therophytes with 47.6% of total species were the most dominant life forms in this area. The most declared reasons for therophytes dominance are short period of growing season, little precipitation, and anthropogenic disturbances such as livestock grazing.

The study aimed to investigate the effect of different stages of decomposition of beech dead trees on the diversity of Coleoptera insects. To acheive this purpose, beech dead trees in different decomposition classess were selected in the compartments 5 and 7 of district 3 in water catchment 46 in Mazandaran province, northern Iran. Coleoptera insects over and under the bark of the selected deadwood stems were collected by fruit traps or mechanical methods and then all specimens of Coleoptera were identified by Skill experts. The results indicated that the maximum and minimum percentage of abundance of the coleoptera insects from the dead woods were observed in the Tenebrionidae family (35%) and in the Brentidae, Curculionidae, and Staphylinidae families, respectively (0.5%). Furthermore, the maximum and minimum percentage of abundance of the coleoptera insects were observed in decay stage 2 and in decay stage 4 of deadwoods, respectively. Moreover, the results showed that the maximum number of insect species and individuals were observed in decay stage 2 and minimum number was revealed in decay stage 4 of deadwoods. Additionally, the results indicated that diversity, richness, and evenness indices were not statistically significant among beech dead trees of different decomposition class.

Nowdays tourism industry as a dynamic and comprehensive industry has incorporated all of the existential elements of a society and global system. Tourism as one of the most extensive world-wide industries & associated with global economy is a phenomenon having high dynamic in economic, political, social & environmental changes which bring about various effects & consequences by influencing on economics, social and environmental foundations.Due to this beliefs, in this study, economical and environmental effects of tourism in Babolsar city are reviewed and some solutions for stable development of tourism will be suggested. to reduce its negative impacts to a minimum plus the benefits resulting from it. This research is a descriptive- analytical one & its statistical community includes Babolsar welling cities in 2012 & based on kocron Formula 381 individuals have been asked questions. After collecting field information through the questionnaire, the relations between study variables have been analyzed by descriptive statistics (frequency table, group …) & inferential (T test) in SPSS software. The analysis conducted that there is a meaningful relationship between the determined variables in each of the areas of tourism effects on economic development and environmental pollution at 0.05% level and meaningfulness level p=0.000. So that 96.6 percent of citizens have evaluated tourism effect in developing of economical components intermediate to excessive, and 98.25 percent of citizens also have evaluated tourism effects in polution of environmental components intermediate to very many.

This study determines the value of the SIASARD natural park in Broujen in Chaharmahal O Bakhtiari province by travel costs. For this purpose 30 questionnaires based on Clawson way was provided and in the distincted 3 days in april these were completed bytourists in the SIASARD natural park in broujen. Recreational value of the park to the travel cost method, the cost of gasoline and cost that spent for per person was estimated that equal with 21608219Rial in per acre.To obtain for pay, simple averaging method was used equal to 7,500 rials per person per month was calculated. Square test was used to determine the relationship between tourist sex and their willing to pay. There was no correlation between gender and willingness to pay. The results show the value of the natural recreation park and provides for policymakers justifies which support for quality of natural parks and prevent of lossing of forest resources.

Ranges as the life bed and development effective of countries has always been interesred of people. But unfortunately today's rangelands in different countries like Iran are destructing. The role of human with the social and economic factors is known as the most important destruction factors. So the man as a beneficiary or the executive director may is partaked in destruction of this vast resource, also prevent of them. The main target of this research is to study the influence of factors on rangeland degradation in Eshtehard, Karaj, Alborz. The method used in his study was based on three elements: library study (documents and evidences), field study and data analysis. Cronbach’s alpha coefficient between 0.71 and 0.87 was obtained. The information required was collected from farmers and experts were working in natural resources offices of the above-mentioned cities, the data was then analyzed by SPSS as well as descriptive and inferential tests. The results obtained showed that from the point of view of both users and experts, changing land application was the most important factor in the destruction of rangelands. Moreover, the Economic and social factors were significantly related to the severity of degradation. In conclusion having found changing land application, designing and performing land use planning seems very essential to the livelihood of the pastures located in the studied region. These findings could also be used by relevant agencies in order to resuscitate the already damaged ranchers.

Awareness of participation barriers of range managers and valuation of each of them for planning government agencies for monitoring and assessment of natural resources is very useful and valuable. This research is based on documents and field study and performed in Doroud city in 1391, sampling method was simple random sampling. Statistical community includes range managers of Dourod city and related experts in the province. Sample was 217 range managers and 50 experts that determine by Cochran formula and replayed to question of reliable and valid questionnaire. Result of correlation coefficient between variables showed that there is no meaningful relationship between age, history, literacy, livestock unit, social-cultural and managerial barriers with participation and between legal and educational barriers, area and range quality with depended participation variable is meaningful relationship. Ranking of range managers and experts opinions performed based on analytical hierarchy process (AHP). The results showed that the instructive barriers and barriers with minimal changes were in the first level and management, economic barriers, legal barriers and cultural barriers - social were in the second to fifth ranks of participation range management respectively. Education is one of the most important factors of public participation that this research expresses this fact and for increase participation in administration of range management plans in Dourod city, addressing this issue by managers of natural resource must be in priority tasks of cultivation works.

Weak Cooperation and Unwillingness of users in rangeland projects is one of the basic challenges that have attracted the attention of the experts. The study aimed to examine factors affecting the willingness of rangelands beneficiaries to contract projects to Range Management. In this study, factors such as quality and condition of the conventional systems, the cooperation between operators in preparing rangeland plans, the number of rangeland users in the customary order, types of exploitation and economical Conditions of operators in conventional systems, order to experts view were examined. The base of sampling method was simple random and the number of 31 samples were determined using Cochran form. Research tools was a questionnaire and survey data collected after coding analyzed using software spss16, K square statistic and Spearman correlation coefficient. Results showed that according to the experts' view, between factors such as economical condition of rangelands users, quality and condition of natural rangelands, and co-operators in range management preparing plans for rangelands users to contract with the range management projects, there was a significant relationship. But there was no significant relationship between the kind of exploitation of beneficiaries and willing to contract for range management, there was no significant relationship and were independent. Reasons that can be expression were rangelands used in a group and enjoyment the same kind of common rights in most common areas of research. It recommend that experts, in order to increasing tendency for beneficiaries to contract projects do the actions in customary order that the context of sustainable social and economical conditions is higher, the number of beneficiaries is low and qualitative condition of rangelands are better.