ECOPERSIA
Volume:9 Issue: 4, Autumn 2021

 Albizia julibrissin is one of the ecologically valuable tree species in the Hyrcanian forest at the Norht of Iran that is endangered due to Fusarium wilt disease. Seeds of these trees have low germination because of their hard coat and dormancy. One of the most effective methods to improve the germination characteristics is seed irradiation during pre-sowing processes. Present study was conducted to improve seed germination characteristics.

  Experiment was arranged by completely randomized design in four replications, five treatments and one control. Seeds were radiated with 60 cobalt source emitting gamma rays at the rate of 0.013 Gray/sec and different doses of gamma rays: 15, 25, 50, 100 and 150 Gray (Gy). All of the seeds were sowing in the moist stratification at 25°C.

 Seed germination started simultaneously 28 days after sowing. Results showed that there is significant difference in germination characteristics between treated seeds and control (p˂0.05). The highest value of seed germination was observed in the 15 Gy (86%), the highest seed vigor index was in 15 Gy treated seeds (266.6), the highest germination speed index  were in 15 and 150 Gy (12.17 and 12.32 seed number day-1 respectively) and the highest mean daily germination were in 15, 50, 100 Gy (7.46, 7.32 and 7.34 number/day respectively).

 Increasing seed germination characteristics was observed in seeds that radiated by low dose of gamma radiation. Hence, lower dose (15 Gy) of irradiation treatment can be used to improve the Albizia julibrissin seed germination characteristics.

Aims :

This study has been done to investigate the effects of access road network of Arasbaran forest areas on erosion in order to achieve appropriate criteria for sustainable development in forest areas while protecting forest soil.

Materials & Methods :

This research was carried out to introduce the SEDMODEL and its capabilities in estimating the production of sediment from road construction Sutanchay watershed in Arasbaran forest, located in the northwest of Iran. From road networks, 10km selected for research. Initially, the maps of geology, slope, rainfall, and drainage density, were prepared in the GIS system. Then, excavation trenches, road surface coverage, and traffic volume were examined in 34 stations through field surveys. The statistical method of Fisher distribution was used to compare the model estimation and observation values.

Findings:

 Statistical analysis of the data showed that there was no significant difference between sediment delivery and Metric method in the erosion assessment resulting from access roads. Standard Error of the metric method and the SEDMODEL was calculated to be 1.34×10-3 and 1.37×10-3, respectively. The results showed that sedimentation caused by road surface was more than 19,000tons, of which 240ton are related to 3km of asphalt road and the rest are related to 7km of dirt road. Total sedimentation of the watershed was estimated to be 46,000ton.

 Conclusion:

 The application of sediment delivery model provides a realistic estimate of forest soil erosion caused by the road network. This model can be considered as a planning criterion in the sustainable development of forest areas.

Aim :

The present study aimed to analyze the strategies based on natural resource potentials to improve the livelihood of rural households in Najafabad region of Kurdistan province using SWOT analysis.

The statistical population of this study included experts and rural residents. The sample size was 337 rural residents and 51 experts based on Cochran formula and matching with Krejcie and Morgan table. The items of questionnaires designed as a rating scale based on the five options Likert. Reliability of questionnaires was determined by Cronbachchr(chr(chr('39')39chr('39'))39chr(chr('39')39chr('39')))s alpha that obtained 0.85 for rural residents and 0.82 for experts. SWOT model was used to determine strategies for improving the livelihood of rural households.

According to the results, “natural potentials such as suitable rangelands for animal husbandry” and “the presence of local, committed and experienced manpower in the village” were determined as the most important strengths from the viewpoint of experts and rural residents, respectively. “Traditional use and exploitation of rangeland and agricultural lands” and “high unemployment rate and low income” were determined as the most important weaknesses from the viewpoint of experts and rural residents, with a relative weight of 86.27 and 86.62, respectively. “The existence of a favorable vision and serious effort for rural development in the country” and “providing credit facilities and low-interest loans” were the most important opportunities.

A competitive strategy has been obtained for improving the livelihood of the studied region relying on teaching and planning new methods of exploiting water resources and planting drought-resistant species.

Aim :

Land use change (LUC) not only affects the plant and soil functional properties, but also influences soil nutrients efficiency. This research was carried out to examine the effect of grassland conversion to dry farming on the efficiency of bio-mineral nutrients in semi-arid loamy soils of northwestern Iran.

Animal manure (AM: 100 and 200 g. Kg-1), useful micro-organisms (UMOs: 1 and 2%), superabsorbent polymers (SAP: 10 and 30 g. Kg-1) and potassium nano-silicate (PNS: 500 and 1000 mg. Kg-1) were used for grass Festuca ovina L. cultivated in grassland and dry farming soil at a completely randomized factorial design.

Based on the results, LUC strongly affected the efficiency of soil nutrients especially PNS (P ≤0.01) where the highest and lowest effects of different nutrients were observed under dry farming and grassland, respectively. A maximum difference of 24.0%, 45.0% and 24.0% were observed in plant biomass, chlorophyll, moisture content, respectively, using 200 g. Kg-1 AM and 30 g. Kg-1 SAP in soil of grassland and dry farming. Also, maximum difference of 71.0% and 67.0% occurred at soil phosphorus and organic matter, respectively between grassland and dry farming.

depending on the type and amount of fertilizer, convert the grasslands to rainfed areas significantly influence plant performance and soil improvement. Overall, due to the undisturbed soil, grasslands show a better performance than rainfed areas under any rehabilitation program.

Parkinsonia aculeata is a valuable medicinal plant in traditional medicine that is more adapted to tropical and subtropical arid regions and planted as an ornamental plant. Since, seed germination of P. aculeata does not occur easily, the current research was performed to test different dormancy breaking treatments on germination characteristics of P. aculeata.

The studied treatments included scarification with sandpaper, H2SO4 (98%), KNO3 (0.2%), soaking the seeds in 90 °C hot water for 15 minutes, Gibberellic acid (250, 500 and 100 ppm), leaching (placing the seeds in running water for 48 hours), combination of leaching treatment with KNO3, and combination of leaching treatment with Gibberellic acid (250, 500 and 100 ppm). To compare the results, distilled water was considered as control treatment. A Completely Randomized Design (CRD) was made with 13 treatments and 4 replications.

Results showed that there were significant differences between treatments on germination percent, germination speed, length of root, length of shoot and length of seedling and index of seed vigor (p<0.01). The seeds had more than 85% dormancy and applying leaching (germination percent, 75%) and scarification treatments (70%) as well as boiling water (57.5%) had the highest effect on releasing the seed dormancy compared to control (15%).

Since, one of the establishment problems of this plant is the seed dormancy period, using leaching for 48 hours will help in germination improvement of P. aculeata.

The study was done to determine the effect of humic acid on germination, morphological properties and photosynthesis pigments of Trifolium alexandrium L. under salt stress.

This study was conducted in a factorial experiment in a completely randomized design (using analysis of variance). The first factor was humic acid (0,0.009mgLi−1). The second factor was salt stress (0,0.75,1.5,3dSm−1). Seed germination, vigor index, allometric coefficient, radicle and pedicle length, total dry and fresh weight, and photosynthetic contents were measured.

The minimum and maximum germination rate (4.00 and 4.90seed/day) and vigor index (1.79 and 6.33) were related to 3dSm-1 and H+3dSm-1 treatments, respectively. The germination percentage did not show significant difference (p<0.05). The radicle and pedicle lengths, allometric coefficient, germination rate and vigor index in the zero treatment were more than the H treatment but they decreased with increasing salinity. The minimum and maximum radicle (0.79 and 2.30cm), pedicle lengths (0.79 and 2.55cm) and dry weight (0.0014 and 0.0026g) were related to the 3dSm-1 and H+3dSm-1 treatments, respectively. The highest chlorophyll a (0.31 mg g-1 fresh weight), carotenoid (0.07 mg g-1 fresh weight) and total chlorophyll (0.48mgg-1 fresh weight) were related to H+1.5dSm-1. The highest amount of chlorophyll b (0.34mg g-1 fresh weight) was observed in H+3dSm-1.

Humic acid had different but positive effects on quantitative properties and germination characteristics of the plant in salinity stress. The use of this fertilizer in salinity stress for salinity-sensitive plants can be useful but more comprehensive survey in the field is recommended.

Watershed management practices are as appropriate solutions to control nonpoint sources of pollution at watershed scale. Nevertheless, the best way to allocate limited resources is a challenge for watershed management efforts. Therefore, to achieve the most suitable strategies, manager requires the use of mathematical techniques to assign management practices priority. In this regards, in the present study, an optimization-based Decision Support Tool (DST) was used to assign the optimal combinations of management practices at the Taleghan Dam Watershed, Alborz Province, Iran.

To achieve the present research goals, Soil and Water Assessment Tool (SWAT) was applied to determine the sediment yield at outlet of the watershed under different combinations of management measures and was coupled with a genetic algorithm in MATLAB computer software, which provides as the optimization engine.

The results of optimization in the Taleghan Dam Watershed showed that implementation costs for 10% and 20% sediment reduction in optimal solution were obtained 110300$ and 235500$, respectively. The cost-effectiveness ratio of scenarios 10% and 20% sediment reduction obtained about 11030 and 11770.5 (dollars for 1% sediment reduction), respectively. The results also showed that filter strip and seeding are the most cost effective option for sediment load control. Conversely, the grade stabilization structure and detention pond are the least cost-effective option.

This tool is transferable to other watersheds and therefore, is one of the effective approaches of watershed management.