Mansoureh Malekian

Comparison and evaluation of dust detection algorithms using MODIS Aqua/Terra Level 1B data and MODIS/OMI dust products in the Middle East

Dust storms have a major impact on air quality, economic loss, and human health over large regions of the Middle East. Because of the broad extent of dust storms and also political–security issues in this region, satellite data are an important source of dust detection and mapping. The aim of this study was to compare and evaluate the performance of five main dust detection algorithms, including Ackerman, Miller, normalized difference dust index (NDDI), Roskovensky and Liou, and thermal-infrared dust index (TDI), using MODIS Level 1B and also MODIS Deep Blue AOD and OMI AI products in two dust events originating from Iraq and Saudi Arabia. Overall, results showed that the performance of the algorithms varied from event to event and it was not possible to use the published dust/no-dust thresholds for the algorithms tested in the study area. The MODIS AOD and OMI AI products were very effective for initial dust detection and the AOD and AI images correlated highly with the dust images at provincial scale (p-value <0.001), but the application of these products was limited at local scale due to their poor spatial resolution. Results also indicated that algorithms based on MODIS thermal infrared (TIR) bands or a combination of TIR and reflectance bands were better indicators of dust than reflectance-based ones. Among the TIR- based algorithms, TDI performed the best over water surfaces and dust sources, and accounted for approximately 93% and 90% of variations in the AOD and OMI AI data.

Effect of landscape features on genetic structure of the goitered gazelle (Gazella subgutturosa) in Central Iran

The populations of goitered gazelle suffered significant decline due to natural and anthropogenic factors over the last century. Investigating the effects of barriers on gene flow among the remaining populations is vital for conservation planning. Here we adopted a landscape genetics approach to evaluate the genetic structure of the goitered gazelle in Central Iran and the effects of landscape features on gene flow using 15 polymorphic microsatellite loci. Spatial autocorrelation, isolation by distance (IBD) and isolation by resistance (IBR) models were used to elucidate the effects of landscape features on the genetic structure. Ecological modeling was used to construct landscape permeability and resistance map using 12 ecogeographical variables. Bayesian algorithms revealed three genetically homogeneous groups and restricted dispersal pattern in the six populations. The IBD and spatial autocorrelation revealed a pattern of decreasing relatedness with increasing distance. The distribution of potential habitats was strongly correlated with bioclimatic factors, vegetation type, and elevation. Resistance distances and graph theory were significantly related with variation in genetic structure, suggesting that gazelles are affected by landscape composition. The IBD showed greater impact on genetic structure than IBR. The Mantel and partial Mantel tests indicated low but non-significant effects of anthropogenic barriers on observed genetic structure. We concluded that a combination of geographic distance, landscape resistance, and anthropogenic factors are affecting the genetic structure and gene flow of populations. Future road construction might impede connectivity and gene exchange of populations. Conservation measures on this vulnerable species should consider some isolated population as separate management units.

The Persian squirrel of Kurdistan Province, western Iran: what determines its geographic distribution?

Abstract Here, we used the maximum entropy (MAXENT) method to predict habitat distribution of the Persian squirrel in oak forests of Kurdistan Province, western Iran. We used 70 points with known occurrence of the species and 17 environmental variables (climatic variables represented annual trends in temperature and precipitation, seasonality and extreme or limiting environmental factors) to map the species distribution. The MAXENT model showed high performance. Using a 0.5 logistic probability threshold, the models suggested about 16,783.5 ha of the study area to have high suitability for the Persian squirrel. These areas were thus estimated as “good” habitats. Amongst the environmental variables, land cover had the greatest role in the Persian squirrel’s distribution. Precipitation and temperature were the two major climatic factors that affected the Persian squirrel’s distribution. Gap analysis showed that many parts of the species habitat have remained unprotected what can threaten the survival of the studied species in the region. These findings can be used to develop conservation management plans and boost the network of protected areas in the region.

Mercury Levels in Common (Actitis hypoleucos) and Green (Tringa ochropus) Sandpipers from West-Central Iran

Mercury concentrations were examined in the liver, kidneys, and tail and breast feathers of common and green sandpipers from Zayanderud Dam in west-central Iran. The aim was to provide indirect information about habitat contamination. Tail feathers of both species had higher mercury levels compared to other tissues. Moreover, tissues of common sandpipers had significantly higher mercury concentrations compared to tissues of green sandpipers. Male specimens of both species had higher values of mercury compared to females. The pattern of larger body size-higher mercury body burden was not completely true in the current study. Smaller and shorter common sandpipers had higher mercury concentrations compared to taller and heavier green sandpipers. At the intraspecific level, body weight was positively correlated with mercury concentrations in tissues of common sandpipers. Based on the data presented here, it appears that these sandpipers, especially common sandpipers, are at potential risk from the toxic effects of mercury.

Patterns and determinants of human-carnivore conflicts in Central Iran: realities and perceptions behind the conflict

ABSTRACT This article assessed the patterns and determinants of human-carnivore conflicts and local attitudes toward carnivores in 18 villages in eastern Isfahan Province, Central Iran. Livestock depredation by carnivores was common, representing a total loss of 3% and 13% of sheep and poultry population, respectively. Over 93% depredation events were attributed to the gray wolf. Households and herders held negative attitudes toward the gray wolf due to their perceived threat to livestock and humans and expressed positive attitudes toward other carnivore species. Preventative measures, such as improved livestock husbandry seem to reduce damage caused by carnivores. In general, livestock that were herded by day with the presence of shepherds and guardian dogs and kept within an enclosure at night with dog presence were 35% less likely to be killed by wild predators. Education influenced peoples’ attitudes toward carnivores.

Characteristics of den, den tree and sites selected by the Persian squirrel in Zagros forests, western Iran

Abstract We investigated characteristics of den, den tree and sites selected by the Persian squirrel (Sciurus anomalus) in the Eastern Dena Protected Area (EDPA), Iran, to provide ecological information for the species conservation. Squirrel dens in the EDPA were located on live oak trees at a mean height of about 2.5 m above the ground, mostly on the main tree trunks and faced mainly towards the north. Compared to randomly selected trees, den trees were significantly higher and had greater canopy cover and access routes. The three main site components selected by principal component analysis included crown canopy cover, number of trees in the plot, and distance to the nearest tree. The species tended to select nesting areas with higher protection from predators and greater food availability. Consequently, to conserve Persian squirrels, mature trees, which are believed to have more cavities and to provide increased food access, should be preserved within the species’ habitats.