COVID-19 and beliefs about tobacco use: an online cross-sectional study in Iran

Environmental Science and Pollution Research - There is mixed evidence surrounding the relationship between tobacco use and COVID-19 infection/progression. The current study investigates beliefs...     

Quantifying the impact of vegetation-based metrics on species persistence when choosing offsets for habitat destruction

Developers are often required by law to offset environmental impacts through targeted conservation actions. Most offset policies specify metrics for calculating offset requirements, usually by assessing vegetation condition. Despite widespread use, there is little evidence to support the effectiveness of vegetation-based metrics for ensuring biodiversity persistence. We compared long-term impacts of biodiversity offsetting based on area only; vegetation condition only; area × habitat suitability; and condition × habitat suitability in development and restoration simulations for the Hunter Region of New South Wales, Australia. We simulated development and subsequent offsetting through restoration within a virtual landscape, linking simulations to population viability models for 3 species. Habitat gains did not ensure species persistence. No net loss was achieved when performance of offsetting was assessed in terms of amount of habitat restored, but not when outcomes were assessed in terms of persistence. Maintenance of persistence occurred more often when impacts were avoided, giving further support to better enforce the avoidance stage of the mitigation hierarchy. When development affected areas of high habitat quality for species, persistence could not be guaranteed. Therefore, species must be more explicitly accounted for in offsets, rather than just vegetation or habitat alone. Declines due to a failure to account directly for species population dynamics and connectivity overshadowed the benefits delivered by producing large areas of high-quality habitat. Our modeling framework showed that the benefits delivered by offsets are species specific and that simple vegetation-based metrics can give misguided impressions on how well biodiversity offsets achieve no net loss.     

The Response of Hydrophytes to Environmental Pollution with Heavy Metals

The effects of Cu²⁺, Cd²⁺, and Ni²⁺ at low and high concentrations (0.025 and 0.25 mg/ml) on the accumulation capacity, the state of the pigment complex, and photosynthesis rate have been studied in model experiments with three floating hydrophytes (Hydrocharis morsus-ranae L., Lemna gibba L., and Potamogeton natans L.) and four submerged hydrophytes (Elodea canadensis Michx., Lemna trisulka L., Ceratophyllum demersum L., and Potamogeton lucens L.). Copper and cadmium are especially toxic at the concentrations studied. The effect of Cu²⁺ was the strongest in hydatophytes, and the effect of Cd²⁺, in pleustophytes. It is hypothesized that the differences between hydrophytes with respect to accumulation of metals and decrease in photosynthesis rate may cause predominant elimination of submerged species. Therefore, changes in the species structure of hydrophyte communities may be expected in waters polluted with metals.     

Experience in quantitative analysis of floristic structure and diversity in Samarskaya Luka

Quantitative methods have been applied to the study of floristic structure and diversity in Samarskaya Luka. The results show that Samarskaya Luka is a floristically heterogeneous area in which six elementary floras can be distinguished. This area has been assessed as a floristically autonomous formation, and its floristic representativeness was estimated.     

Ecological and physiological differences between two colour morphs of the coral Pocillopora damicornis

Pocillopora damicornis (Linnaeus) is a ubiquitous branching coral found throughout the Indo-Pacific region. Like many other species of coral, P. damicornis displays a large range of morphologies. At One Tree Island, it occurs as two distinct morphs that are easily distinguished by the presence or absence of pink pigmentation. The two colour morphs of P. damicornis were found to differ in their distribution and abundance in the One Tree Island Lagoon. The brown morph was more abudant than the pink morph in the shallows (<1 m),whereas the pink morph was more abundant at deeper sites (>3 m). The two morphs also differed physiologically. The brown morph tended to have a greater calcification rate than the pink morph, regardless of environmental conditions. However, the difference in the calcification rate between the two morphs became non-significant under shaded conditions (5% full sunlight), indicating some degree of physiological plasticity of the morphs. The pink colour in P. damicornis was due to a hydrophilic pigment with a major peak absorbance at 560 nm. The expression of pink pigment had both genetic and phenotypic components. The brown morph has a reduced genetic capacity to express the pigment relative to the pink morph. On the other hand, pigment expression could be induced by light in the pink morph. Although genetic differences ultimately determine the differences between the two morphs of P. damicornis, the extent of pigment expression is under some degree of environmental influence.     

Pentachlorotoluene and pentabromotoluene: results of a subacute and a subchronic toxicity study in the rat

Pentachlorotoluene (PCT) and pentabromotoluene (PBT) are environmental contaminants detected in the Great Lakes ecosystem. In view of the paucity of toxicity data and the potential for human exposure, a subacute (28 day) and a subchronic (91 day) study were conducted in the rat. In the subacute study, groups of 10 male and 10 female rats were fed the diet containing PCT or PBT at 0, 0.5, 5.0, 50 or 500 ppm for 28-days. In the subchronic study, the group size was increased to 15, the dose levels were 0, 0.05, 0.5, 5.0, 50 and 500 ppm in the diet and the exposure period was 91 days. Growth rate and food consumption were not affected by exposure to either chemical in the subacute and subchronic study. Clinical observations revealed no abnormalities. Decreased hemoglobin was observed in female rats fed 5.0 ppm PCT and higher levels in the subacute (28 day) study. In the same study the hematocrit value and erythrocyte numbers of females fed 5.0 or 500 ppm PCT diets were significantly lower than the control. In both subacute and subchronic studies mild dose-dependent histopathological changes were observed in the thyroid, liver and kidney of rats fed PCT and PBT diets. In general male rats were more susceptible than females to the treatment of PCT and PBT. Based on these data, it was concluded that the no observable adverse effect level for PCT was 50 ppm in the diet (3.5 mg/kg b.w./day) and that of PBT was 5.0 ppm (0.35 mg/kg b.w./day).     

The Spatiotemporal Pattern of Fires in Northern Taiga Larch Forests of Central Siberia

The periodicity of fires in larch forests of Evenkia and their relationship with landscape elements have been studied. Cross-sections with “burns” in them caused by past fires have been analyzed in 72 test plots; the fire chronology encompassed the period from the 15th to the 20th century. The between-fire intervals (BFIs) have been calculated by two methods: (I) on the basis of burns alone and (II) on the basis of burns and the start of growth of the new generation of larch after the earliest fire. The BFI depends on local orographic features; it is 86 ± 11 (105 ± 12), 61 ± 8 (73 ± 8), 139 ± 17 (138 ± 18), and 68 ± 14 (70 ± 13) years for northeastern slopes, southwestern slopes, bogs, and flatlands, respectively. The mean BFIs calculated by methods I and II are 82 ± 7 and 95 ± 7 years, respectively. The permafrost horizon rises at a mean rate of 0.3 cm per year after a forest fire. It has been shown that the number of fires regularly peaks at periods of 36 and 82 years. There is also a temporal trend in fire frequency: the mean BFI was approximately 100 years in the 19th century and 65 years in the 20th century.