Contrasting approved uses against actual uses at La Restinga Lagoon National Park, Margarita Island, Venezuela. A GPS and GIS method to improve management plans and rangers coverage

Protected areas are the core of efforts to conserve biological diversity and zoning uses, and they are used as a tool for their management. Global Positioning Systems (GPS) and Geographic Information System (GIS) have been used to evaluate conflicts between approved uses and actual uses in La Restinga Lagoon National Park in Venezuela (LRLNP). The park (188.6 km²), covers various ecosystems such as coastal lagoons, marine waters and xerophytic vegetation, it is visited by up to 260,000 people visit per year. A GIS, using a base map compiled from 1:25,000 maps was developed. Natural cover was mapped from LANDSAT VII TM images, orthophotomaps and aerial photographs. Spatial use data was collected by field GPS location of any use inside the park during 2 years. Thematic vector maps for each land cover, zoning area, and observed use were created. Maps of zoning and uses were overlapped and new maps for each use-zoning crossing were created. The park contain nine different zoning areas wherein 28 different uses were identified, 18 of them were direct consumptive and non-consumptive uses, occurring on 54% of the park. Tourism transit areas were the most used zones. More than 5,000 people use the park during a high season day. Superimposition of zoning maps with actual use data produced 13 uses taking place in not allowed areas (46% of park area). Most common prohibited use was commercial net fishing, occurring in nearly 40% of the park area. Therefore, identifying human use conflicts and its geographical distribution is a key issue to improve Management Plans as well as identifying hot sites. The GPS-GIS methodology presented here allows Park Rangers to select those areas which could benefit from enhanced supervision with the limited budget available.     

Atmospheric deposition of 137Cs between 1994 and 2002 at Cienfuegos, Cuba

Levels of 137Cs in total atmospheric deposition have been measured in the Cienfuegos region (Cuba) between 1994 and 2002. Samples were collected every three months, evaporated to dryness to obtain residual samples, and measured by gamma spectrometry. The 137Cs mean concentration in total deposition was 0.24 Bq m(-2) and data ranged between < 0.05 and 0.62 Bq m(-2). Precipitation rates and raintime have proved to be the most important factors controlling the concentration and depositional flux of 137Cs in the atmosphere over Cienfuegos, showing a high correlation coefficient (R = 0.93).     

Chemosensory assessment of rival body size is based on chemosignal concentration in male Spanish terrapins

Assessment of the fighting ability of potential opponents is an essential skill to minimize the costs of agonistic interactions between males. Previous research showed that chemical cues released in the water by male turtles may convey information about body size, which is important for intrasexual competition. However, the mechanistic basis of such chemical signaling of body size remains poorly understood. Here, we aimed to experimentally examine whether the release of chemosignals is quantitatively or qualitatively dependent on body size in male Spanish terrapins Mauremys leprosa. We compared the time that turtles spent in a pool with clean water versus water containing chemical stimuli of conspecific males of different body sizes at two different concentrations (“diluted” or “undiluted”). Male terrapins avoided water with chemicals secreted by relatively larger males when these chemicals were undiluted, but not after the chemical stimuli were diluted. In contrast, male terrapins did not avoid chemicals of relatively smaller males in any treatment. Thus, male M. leprosa may assess the size of their rivals on the basis of the concentration or the amounts of their chemical cues released into the water and consequently avoid occupying these ponds with higher concentrations of chemicals. This study gives important hints about the mechanism of chemical signaling in freshwater turtles and demonstrates that male turtles may discriminate different concentrations of chemosignals of conspecifics and modify their behavior accordingly. Likewise, our results support the notion that relative body size is a key factor during male interactions in Spanish terrapins.     

Effects of Management on Understory Diversity in the Forest Ecosystems of Northern Spain

Pine plantations are an alternative to marginal agriculture in many countries, and are often presented as an option that improves biodiversity. However, these plantations can have adverse environmental effects if improperly managed. To evaluate the effect of forest management practices on biodiversity, the diversity, species richness, dominance and frequency of understory woody plant species in different forests of the Basque Country (northern Spain) were compared. Plantations of exotic conifers (Pinus radiata [D.] Don) of different ages were compared with deciduous forests of Quercus robur L. and Fagus sylvatica L. The effects of different types and intensities of management were taken into account. The differences observed were mainly conditioned by the intensity of forestry management, although the response varied according to forest type and age. In unmanaged pine plantations, the diversity and species richness of the understory increased rapidly after planting (while dominance decreased), remained stable in the intermediate age range, and reached a maximum in plantations more than 25 years of age. Management practices resulted in decreased understory diversity and species richness, as well as greater dominance. This was more pronounced in younger than in older stands. Moderate management, however, favored a greater diversity of the understory in deciduous forests. The species composition of the plantations and deciduous forests were different, the latter having a wider range of characteristic species. Knowledge of how forestry practices influence biodiversity (in terms of diversity, richness, dominance, and species composition) may allow predictions to be made about the diversity achievable with different management systems.     

Application of the new C18 speedisks to the analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans in water and effluent samples

A recently introduced disk for solid-phase extraction of pollutants from water (C18 Speedisk) has been tested for the analysis of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). The complete procedure of analysis has been validated with spiked deionized water. The accuracy, expressed as recovery for the sum of 2,3,7,8-substituted congeners. is 92% and the precision, expressed as the RSD of reproducibility, is 5.8%. The limit of detection (LOD), using 2 l of water, is 4.2 pg/l (0.6 pg ITEQ/l) for the sum of 2,3,7,8-substituted congeners. Actually, the C18 Speedisks have substituted the use of other C18 membrane disks in our laboratory because they allow the fast and efficient analysis of samples with high content of suspended material and reduce the time of elution of free-particulate samples. These disks have been successfully applied to the analysis of water from different sources and with very different physical and chemical characteristics: seawater, rain water, an industrial effluent, a landfill leachate and the inlet and chlorinated and non-chlorinated outlet water from a wastewater treatment plant.     

Information system for the registration of pollution sources associated with construction activities

A prospective builder in Czech Republic has to apply for approval by local (regional, state) authorities and is liable, in the Environmental Impact Assessment (EIA) process to make an accurate statement of stress factor values produced during the life cycle of the construction work.These data should be kept in the information system, as only a substantial amount of relevant high quality data can be used in the decision-making process.Identifying and quantifying stress factors produced by a given construction activity can present a problem due to inadequate knowledge and opinion in this field. For large construction works, a knowledge-based system proposed in the second part of this paper may be useful; small structures can be covered by the information given as to local factors, which form part of the information system proposed by Vlcek and Moos (1991).     

Compositional analysis of topsoil metals and its associations with cancer mortality using spatial misaligned data

The presence of toxic metals in soil per se, and in soil impacted by mining, industry, agriculture and urbanisation in particular, is a major concern for both human health and ecotoxicology. The dual aim of this study was: to ascertain whether topsoil composition could influence the spatial distribution of mortality due to different types of cancer and to identify possible errors committed by epidemiological studies which analyse soil composition data as a closed number system. We conducted an ecological cancer mortality study, covering 861,440 cancer deaths (27 cancer sites) in 7917 Spanish mainland towns, from 1999 to 2008. Topsoil levels of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined by ICP-MS at 13,317 sampling points. We transformed the topsoil data in two ways, i.e. log transformation and centred logratio transformation. Principal factor analysis was performed to obtain independent latent factors for the transformed variables. To estimate the effect on mortality of topsoil factor loadings, we fitted Besag, York and Mollié models embedded in geostatistical-spatial models. This model included soil sample locations and town centroids (non-aligned data), fitted using the integrated nested Laplace approximation (INLA) as a tool for Bayesian inference and stochastic partial differential equations (SPDE). All results were adjusted for socio-demographic variables. The results indicated that soil composition could have an influence on the spatial distribution and mortality patterns of cancer. The analysis adjusted for socio-demographic variables showed excess male mortality due to digestive system tumours in areas with soils containing higher Cd, Pb, Zn, Mn and Cu concentrations, bladder cancer in areas with soils containing higher Cd concentrations, and brain cancer in areas with soils containing As. In both sexes, cancer of oesophagus was associated with soils containing a higher lead content, while lung cancer was associated with soils containing a higher copper content. Stress should be laid on the importance of taking into account the compositional nature of the data in this type of analysis.     

Assessing performance and closure for soil vapor extraction: integrating vapor discharge and impact to groundwater quality

Soil vapor extraction (SVE) is typically effective for removal of volatile contaminants from higher-permeability portions of the vadose zone. However, contamination in lower-permeability zones can persist due to mass transfer processes that limit the removal effectiveness. After SVE has been operated for a period of time and the remaining contamination is primarily located in lower-permeability zones, the remedy performance needs to be evaluated to determine whether the SVE system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. Numerical modeling of vapor-phase contaminant transport was used to investigate the correlation between measured vapor-phase mass discharge, MF(r), from a persistent, vadose-zone contaminant source and the resulting groundwater contaminant concentrations. This relationship was shown to be linear, and was used to directly assess SVE remediation progress over time and to determine the level of remediation in the vadose zone necessary to protect groundwater. Although site properties and source characteristics must be specified to establish a unique relation between MF(r) and the groundwater contaminant concentration, this correlation provides insight into SVE performance and support for decisions to optimize or terminate the SVE operation or to transition to another type of treatment.