مجله تحقیقات حمایت و حفاظت جنگلها و مراتع ایران
سال یازدهم شماره 1 (پیاپی 21، بهار و تابستان 1392)

August thorn, Ennomos quercinaria (Lep.: Geometridae) has been recognized as an important defoliator of forest trees throughout the world. Several outbreaks have been observed in Mazandaran province during the last decade. Study on the biology of this pest in laboratory conditions revealed that it has six larval instars. Average larval longevity estimated as 46.16±3.74 days. Larvae are green to brown in color and pupate among folded leaves. The pupal period of males and females were 13.85±0.25 days and 12.44±0.16 days, respectively. Males had longer life span (7±0.44 days) compared with the females (5.76±0.25 days). Life cycle averaged 64.52±5.86 days. The flight period was recorded from May through late June. Agust thorn is a univoltine insect and overwinters as an egg among foliage of the host trees. In this study, six spiders, two beetles, three wasps and a fly were identified as natural enemies.

One of the initial actions in the management of forest lands and reduce the losses caused by this phenomenon is identifying areas prone to fire risk. Determine the probability of a fire hazard is effective in the prevention and management of fires. In this study, fire hazard zonation map in Doroud city was prepared and examined using statistical modeling. For the modeling, multivariate regression analysis in the SPSS software was used. 63 samples include burned and non burned lands were detected. Burned area as the dependent variable and the factors affecting fire occurrence consists of annual rainfall, the proximity (roads and residential areas), elevation, slope, percentage of vegetation cover, etc. were considered as independent variables. The quantitative values of above parameters were estimated using available maps in the Geographical Information System (GIS) and Remote Sensing (RS) environment as well as field studies. Regression analysis performed for the proposed model and validation of the model's performance was carried out. The amount of vegetation cover and rainfall were the most important factors affecting fire incidences. Finally fire hazard zonation map was prepared by applying validated model in GIS environment. The research results substantiate the effectiveness of the proposed model for fire hazard assessment.

The sainfoin "Onobrychis sativa L." is a forage and rangeland plant which is susceptible to powdery mildews. For surveying of 34 populations to the disease severity of powdery mildew, seeds of populations were planted in research station of Serab Changai, at North West of Khorramabad by 1 2 m plots with 3 replications. The measurement of disease severity of each population was done for each harvest by 3 years. Then the data were analyzed by SAS and then the populations divided to 4 group of tolerant, semi susceptible and susceptible to this disease. According of disease severity index, 34 populations were divided to 22 statistical groups (p<0.05). The population of Polycrass and Oshnavieh with 18 and 19 percent of disease severity had lowest disease severity in comparison with other populations, therefore they evaluated as tolerant groups. Disease severity index of the populations of Khansar2 and Khalkhal were 40 and 37 percent of disease severity and they stand as semi suecceptible group. Another population, were evaluated between this 2 group for disease severity index.

Turfgrasses have been recognized for their importance to our quality of life for many years. Today, they are cultured as a main component of cool-season grasses in the landscape and sport fields in Iran. Turfgrasses are susceptible to Fusarium species. To study the role of Fusarium species as the causal agents of foliar blight, crown and root rot of turfgrass, samples were collected from infected turfgrass plants from different areas in landscapes of Tehran, Ardebil, Khorasan and Khoozestan provinces during 2009 - 2010. Based on morphological and physiological characteristics and the diagnostic keys a total of 101 isolates seven species of Fusarium recovered. These include: F. solani (33%), F. chlamydosporum (8%), F. proliferatum (2%), F. graminarum (13%), F. oxysporum (8%), F. subglutinans (9%) and F. compactum (28%). Fusarium isolates were found pathogenic using their conidial suspensions in the soil of the one month- old turfgrass seedlings used in Iran as Baronburg trade mark which is mixed of Lolium perenne, Festuca rubra and Poa pratensis seeds in the greenhouse conditions. Based on the more pathogenic effect, the order of Fusarium species were: F. solani, F. subglutinan, F. chlamydosporum, F. oxysporum, F. compactum, F. graminearum, F. poliferatum, respectively. Pathogenicity test for above Fusarium isolates against five major genera of turfgrasses including: Poa pratensis (Kentucky bluegrass), F. rubra (Fescue), Agrostis stolonifera (Bentgrass), Lolium perenne (Rye grass) and Cynodon dactylon (Bermudagrass)– were also performed under greenhouse conditions. The results showed that Rye grass, Fescue, Kentucky bluegrass Bermuda grass and Bentgrass were more resistant to isolates of tested Fusarium species, respectively Pathogenicity test for any of five turfgrasses against above Fusarium species was performed on one month- old seedlings under greenhouse conditions. The virulence of the fungal isolates was evaluated.

Inappropriate land use triggers and accelerates desertification process in arid and semi arid regions. The aim of this study was to evaluate the desertification impacts in Qom province through land cover/ land use changes in 33 years using Land sat 1976 TM, 1992 and 2009. Population data, livestock numbers and SPI indices were also compared during this period. First, geometric, radiometric and topographic preprocessing techniques were applied to the images and land use/cover maps were extracted using supervised classification (Maximum likelihood) and fuzzy method. The maps accuracies were assessed through overall accuracy and Kappa statistics. According to the results, the maps produced by Fuzzy methods had more accuracy than the Maximum likelihood method. The results also indicated that the size of rangelands decreased from 784281.to 662910 hectares and 34112 hectares of lands were transformed into salty areas during this period. The results showed that the size of urban and industrial areas and agricultural lands in the province were increased to 2864 and 131308 hectares, respectively. The Namak Lake was also completely dried in 2009. The results revealed that dam constructions, pumping underground water, continuous droughts and increasing livestock numbers were among the reasons of accelerating the desertification trend in Qom province especially in the eastern part; hence both management and environmental variables were responsible for these changes. Holistic and adaptive management approaches in natural resources management, and especially in water resource management can restore the province into the past conditions.

Lead (Pb) is one of the most dangerous contaminants to environment. This element has ability to remain in soil for long time and being poisonous to human, animal and plants. Using lead hyper-accumulator plants is a useful method for lead elimination from plotted environment. Lead tolerance determined in three Salix species (Salix alba, S. acmophylla and S. fragilis), in a completely randomized design experiment at Pb concentrations of 0, 50, 100 and 200 mM with 3 replications in form of Pb(No3)2 applied in water of irrigation on 130 days old seedlings. Physiological characters such as sugar soluble, proline, total chlorophyll and Pb concentration in leaves, stem and root measured with ICP (Inductivity Coupled Plasma) device by fresh oxidation's method on the Salix's seedlings, after 75 days of lead treatments. The maximum amount of Pb fund in leaves of S. alba (311.91 mg/kg dwt) and in roots of S. fragilis (1631.4 mg/kg dwt). With due attention to, S. alba had the most soluble sugar and free proline at 200 and 100 mMPb treatments (1477.78 and 14.18 mg/kg dwt respectively), it can be used for lead reduction from polluted environmental.

In order to study the phytophagous flies of the family Chloropidae in grasslands of East Azarbayjan province, a survey was carried out during 2009-2013.Seven species belonging to two genera were identified of which six species are newly recorded for the Iranian insect fauna as Chlorops adjunctus, C. calceatus, C. figuratus, C. puncticornis, C. serenus and Meromyza variegate.