Development and application of an ecosystem management approach for protected natural areas

Preservation of small natural areas is not in itself a sufficient measure to maintain the integrity of the ecosystems for which they were initially set aside. Intense pressure from recreational use is just one of the many human-caused stresses that may degrade natural areas. Therefore, land-use planning and management from an ecological perspective is necessary to assess, ensure, and in some cases increase, the ecological integrity of protected natural areas. An ecosystem management approach for small protected natural areas with high recreational use is presented, based on three interrelated components: an ecological evaluation procedure of ecosystems, the implementation of management interventions on ecosystems, and the development of a monitoring scheme of ecosystem components. The ecological evaluation procedure combines two concepts: the biotic value of vegetation and wildlife and the abiotic fragility of the soils. This combined evaluation process results in the creation of a sensitivity map that can be used as a management tool for planners and managers. Management interventions, the second component of the management approach, are derived from concepts of ecological succession. Intentional human interventions are used to maintain the ecological integrity of ecosystems or in some cases to restore degraded sites. For the third component, only the basic principles of the monitoring program will be discussed. A pilot project in one of the Montreal urban community protected areas is presented to illustrate aspects of the proposed ecosystem management approach.     

Methylmercury genotoxicity: a novel effect in human cell lines of the central nervous system

Methylmercury is an important source of environmental contamination and the central nervous system (CNS) is one of the main target organs. Methylmercury genotoxicity was already demonstrated in peripherical tissues but was never detected in the brain. Thus, the objective of this work was to verify its genotoxic effect using brain cell lines. Glioblastoma (U373) and neuroblastoma (B103) human cell lines were exposed to methylmercury (0-10 microM). By measuring cellular viability, concentrations inducing <20% of cellular death (P<0.05) were selected: 1 and 0.1 microM. To detect micronuclei, 200,000 cells were treated with methylmercury for 24 h, and then incubated with cytochalasin B (2 microg/ml) for 72 h (U373) or 48 h (B103). The binucleation index, frequency of micronucleated cells, micronucleation index, metaphasic index and index of nucleoplasmic bridges were determined. Statistical analysis showed indices and percentages significantly higher (P<0.05) in methylmercury-treated cells. Each cell line was shown to be differently sensitive to each biomarker of genotoxic damage, which seems to indicate the existence of different mechanisms of toxicity. This work demonstrates, for the first time, MeHg ability to provoke genotoxicity in cells of brain origin with relatively low levels of exposure.     

Effects of different management strategies on long-term trends of Australian threatened and near-threatened mammals

Monitoring is critical to assess management effectiveness, but broadscale systematic assessments of monitoring to evaluate and improve recovery efforts are lacking. We compiled 1808 time series from 71 threatened and near-threatened terrestrial and volant mammal species and subspecies in Australia (48% of all threatened mammal taxa) to compare relative trends of populations subject to different management strategies. We adapted the Living Planet Index to develop the Threatened Species Index for Australian Mammals and track aggregate trends for all sampled threatened mammal populations and for small (<35 g), medium (35–5500 g), and large mammals (>5500 g) from 2000 to 2017. Unmanaged populations (42 taxa) declined by 63% on average; unmanaged small mammals exhibited the greatest declines (96%). Populations of 17 taxa in havens (islands and fenced areas that excluded or eliminated introduced red foxes [Vulpes vulpes] and domestic cats [Felis catus]) increased by 680%. Outside havens, populations undergoing sustained predator baiting initially declined by 75% but subsequently increased to 47% of their abundance in 2000. At sites where predators were not excluded or baited but other actions (e.g., fire management, introduced herbivore control) occurred, populations of small and medium mammals declined faster, but large mammals declined more slowly, than unmanaged populations. Only 13% of taxa had data for both unmanaged and managed populations; index comparisons for this subset showed that taxa with populations increasing inside havens declined outside havens but taxa with populations subject to predator baiting outside havens declined more slowly than populations with no management and then increased, whereas unmanaged populations continued to decline. More comprehensive and improved monitoring (particularly encompassing poorly represented management actions and taxonomic groups like bats and small mammals) is required to understand whether and where management has worked. Improved implementation of management for threats other than predation is critical to recover Australia's threatened mammals.     

One-dimensional numerical modelling of dam-break waves over movable beds: application to experimental and field cases

This paper reports a numerical study on dam-break waves over movable beds. A one-dimensional (1-D) model is built upon the Saint-Venant equations for shallow water waves, the Exner equation of sediment mass conservation and a spatial lag equation for non-equilibrium sediment transport. The set of governing equations is solved using an explicit finite difference scheme. The model is tested in various idealized experimental cases, with fairly good agreement between the numerical predictions and measurements. Discrepancies are observed at the earlier stage of the dam-break wave and around the dam location due to no vertical velocity component being taken into account. Sensitivity tests confirm that the friction coefficient is an important parameter for the evaluation of sediment transport processes operating during a dam-break wave. The influence of the non-equilibrium adaptation length (or the lag distance) is negligible on the wavefront celerity and weak on the free surface and bed profiles, which indicates that one may ignore the spatial lag effect in dam-break wave studies. Finally, the simulation of the Lake Ha!Ha! dyke-break flood event shows that the model can provide relevant results if a convenient formula for computing the sediment transport capacity and an appropriate median grain diameter of riverbed material are selected.     

Environmental remediation processes by zero valence copper: reaction mechanisms

Environmental Science and Pollution Research - Recent studies have shown Cu(0) as a promising material for the removal of organic and inorganic pollutants. However, there is no review addressing...     

Human intoxication by agrochemicals in the region of South Brazil between 1999 and 2014

The objective of this study was to evaluate pesticide poisonings in the southern region of Brazil between years 1999 and 2014. Data were collected from the database Sinitox. Intoxications and deaths were evaluated according to the distribution by gender (female and male), age group (≤14, 15–59 and ≥60 years), area of occurrence (urban and rural), circumstance (accident, occupational and suicide attempt) and evolution of the cases over time (cure, unconfirmed cure, death and sequelae). In the evaluated period, 21,305 cases of intoxication were registered. The results show that males between the ages of 15 and 59 years are more affected; and there is a greater representativeness in the urban area. These results are related to the application of agrochemicals being carried out by individuals between 15 and 59 years of age. The great correlation of urban area possibly occurs in function of the air currents brought from the field and as a result, population has been more affected and the consumption of contaminated food. It was observed that women handling pesticides more cautiously, in this way the accidents with male gender are more frequent, however, many women use the product intentionally to provoke suicide.     

Identification and quantitation of semi-crystalline microplastics using image analysis and differential scanning calorimetry

Environmental Science and Pollution Research - There are several techniques used to analyze microplastics. These are often based on a combination of visual and spectroscopic techniques. Here we...     

Contamination by lead in sediments at Toledo River,hydrographic basin of PARANÁ III

Due to intense agricultural and industrial activities, the environment has been affected by increasing amounts of pollutants, such as lead, a toxic heavy metal. When introduced to the environment, toxic metals are distributed and incorporated into the liquid medium, sediments, and aquatic biota; bioaccumulating. This research aimed to identify and quantify the levels of toxic metals present in the waters and sediments of Toledo River, compare the obtained results with legislation and other studies, as well as to evaluate the possible pollutant sources of the water body. Six water and sediment samples were taken at seven strategic sites. The concentrations of Cu, Zn, Fe, Mn, Cd, Pb, and Cr in water were compared to the maximum limits established by Brazilian legislation IN CONAMA No. 357/05, for class II fresh waters. The sediment samples were submitted to nitroperchloric digestion, and then the total concentrations of the metals were determined by flame atomic absorption spectrometry (FAAS). The toxicological quality of the Toledo River has been considerably affected by the activities carried out in its surroundings, such as extensive areas of agriculture, pig farming and industrial areas, causing concentrations of Cd, Fe, and mainly Pb, which is observed at concentrations higher than value allowed by the legislation.     

The relative importance of subjective and structural factors for individual adaptation to climate change by forest owners in Sweden

A growing body of literature argues that subjective factors can more accurately explain individual adaptation to climate change than objective measurers of adaptive capacity. Recent studies have shown that personal belief in climate change and affect are much better in explaining climate awareness and action than income, education or gender. This study focuses on the process of individual adaptation to climate change. It assesses and compares the influence of cognitive, experiential and structural factors on individuals’ views and intentions regarding climate change adaptation. Data from this study comes from a survey with 836 forest owners in Sweden. Ordinal and binary logistic regression was used to test hypotheses about the different factors. Results show that cognitive factors—namely personal level of trust in climate science, belief in the salience of climate change and risk assessment—are the only statistically significant factors that can directly explain individuals’ intention to adapt to climate change and their sense of urgency. Findings also suggest that structural or socio-demographic factors do not have a statistically significant influence on adaptation decision-making among Swedish forest owners. The study also offers valuable insights for communication interventions to promote adaptation. Findings strongly suggest that communication interventions should focus more strongly on building trust and addressing stakeholders’ individual needs and experiences.