Identifying Key Habitats to Conserve the Threatened Brown Bear in Northern Iran

Many factors such as human activities threat brown bears (Ursus arctos) in Southern Asia, and limit it to small populations in remote and rocky mountainous regions. Brown bears are generally studied in North America and Europe, but there is little information about its conditions and requirements for survival in Asia. During the recent years, brown bear populations in Iran have decreased sharply. Therefore, they are now officially listed as a threatened species in local scale. Therefore, we tried to recognize brown bear habitat relationships in northern Iran using species distribution model (SDM). Maxent method was applied using multiscale approach to predict suitable habitats and habitat relationships of the species. Our results revealed that the predictive ability of environment variables and species distribution maps varied across scales strongly. Also, our findings showed that identifying a proper scale is important issue to improve habitat modeling accuracy. Only 17% of the protected areas was found suitable for brown bear and divided to 5.1% poor, 8.8% suitable, and 3.1% high-quality habitat. Consequently, it is suggested that the protected area of northern Iran reconsiders with interventions aimed at maintaining suitable habitats of brown bear.     

Variation in the Composition of Secondary Metabolites in <Emphasis Type="Italic">Flavocetraria</Emphasis> Lichens from Western Siberia

The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day.     

Ecophysiology of Steppe Mouse Subspecies <Emphasis Type="Italic">Mus spicilegius spicilegus</Emphasis>, Peteni, 1883 (Rodentia,Mammalia) at the South Boundary of its Distribution

Diet, food preferences and main ecophysiological characteristics such like energy requirements and thermoregulation characteristics of Mus spicilegus spicilegus (Petenyi, 1882) were studied. The most preferred foods for the mice were seeds of weed species that composed more than 85% of their diet. The results of food selection experiments shows that the total daily consumption by mice is 2.77 ± 0.76 g/animal/day or 5.5 kJ/g/day or 84.9 kJ/animal/day. From the total daily energy consumption 16.4% go back to nature in the form of feces and urine and the rest 83.6% animals utilized for assimilation. The results of the temperature preferences for Mus s. spicilegus shows preferred temperature zone from around 26 to 36°C where mice spent about 72% of the experimental time. The lowest value of oxygen consumption for resting metabolism rate (RMR) was registered at 30°C–3.20 ± 0.71 cm³ O₂/g/h. It is possible to consider that the thermoneutral zone is around these temperature values. The obtained results give reason to conclude that from an ecophysiologycal point of view the climate in the south boundary of distribution provides optimal conditions for species development. The main cause for population decreasing probably is the loss of open habitats including natural steppe grasslands.     

Holocene Dynamics of Vegetation and Ecological Conditions in the Center of the East European Plain

Changes in the vegetation and fire regimes in the central East European Plain during the second half of the Holocene have been reconstructed based on the results of paleobotanical analysis and radiocarbon dating of material from a section of peat deposit in the Mordovia State Nature Reserve. It has been shown that birch–pine forests were widespread in the region between 7000 and 5000 yr BP, with the frequency of fires in that period being high (the fire return interval ranged from 10–20 to 100 years). Beginning from 5000 yr BP and to the early 20th century, broadleaf forests were dominant, with the fire return interval increasing to 300–500 years or longer.     

Assessment of the State of Lung Lichen, <Emphasis Type="Italic">Lobaria pulmonaria</Emphasis> (L.) Hoffm., in Forest Communities with Different Times Since Disturbance in the Northeast of European Russia

Quantitative parameters of cenopopulations of Lobaria pulmonaria, an endangered cyanolichen, have been studied in spruce phytocenoses of Karelia recovering after disturbance through the successional stage of aspen stands for a period ranging from 80 to 450 years. The results show that, as the time since disturbance increases, the total number of L. pulmonaria thalli and the number of colonized substrate units increase as well, with no stabilization of these parameters being observed in the series of communities studied. The total area of thalli in the phytocenoses is restored within approximately 200 years after the last disturbance. In old-growth forests (>400 years), L. pulmonaria thalli colonize a broad spectrum of tree species in different life states, including lower branches of young spruce trees. Even if they serve as temporary substrates, this can markedly strengthen the potential of the species for further expansion within the community in case of shortage in the main phorophyte (aspen). Thus, the proportion of regressive populations decreases, while that of colonizing populations increases, which is indicative of successful reproduction of the species.     

Social justice and mobility in coastal Louisiana,USA

Regional Environmental Change - Louisiana faces extensive coastal land loss which threatens the livelihoods of marginalized populations. These groups have endured extreme disruptive events in the...     

A Mathematical Model for the Effects of Fertilization on Nitrogen Concentrations in Unsaturated Soil on Blueberry Farms in Southern New Jersey

Nitrogen is commonly known as a food source for crops. However, the nitrogen compounds used in crop fertilizers, most commonly nitrate (NO₃) and ammonium (NH₄), are not widely understood. Blueberry plants do not take up these compounds as efficiently as organic nitrogen so varying amounts of leaching into the soil and groundwater will occur. A biogeochemical model consisting of ordinary and partial differential equations is implemented to computationally predict the concentrations of nitrate and ammonium in unsaturated soil of blueberry plants, specifically in the southern region of New Jersey. The model takes into account the type of soil of the region, the nitrate uptake of the plant, the water content in the roots region, the pressure heads in the soil pores, and the application rates of fertilizers containing nitrate, ammonium, and organic nitrogen. Computational simulations demonstrate that the model accounts for natural processes and, in addition, show that commonly used fertilizer application rates cause unnecessarily high concentrations of both nitrate and ammonium in the unsaturated soil level. Further, simulations show that decreasing nitrate fertilizer applications by 85.7% in annual and 91.8% in bi-annual schedules provides an optimal system for safe reapplication.     

GPU Accelerated Lattice Boltzmann Simulation of a Cyanide-Release Accident in the Danjiangkou Reservoir

A graphics processing unit (GPU) accelerated two-dimensional contamination transport model is developed using the lattice Boltzmann method (LBM). The intrinsic parallel features of LBM make it particularly suitable for implementation on GPUs. After validation with two benchmarks, the model was applied to a cyanide-release accident in the Danjiangkou Reservoir, using a numerical combination of hydrodynamics and solute transport. The results show good agreement with an Environmental Fluid Dynamics Code (EFDC) model. A single GPU workstation speedup reaches 1.58 times that of a central processing unit (CPU) calculation alone. This speedup provides the opportunity for applying the model as a pollution accident information and decision support system for the Middle Route of the South to North Water Diversion Project in China.