Non-linear ecological processes, fires, environmental heterogeneity and shrub invasion in northwestern Patagonia

The emergent behaviors of nature are not only the sum of interactions among ecosystem parts but also depend on the organization of these interactions. Fire, climate and vegetation patterns produce non-linear fire propagation across the landscape. Environmental heterogeneity, like outcrop presence and hare density, increases landscape patchiness and makes possible the occupation of fire refuges by plants, like Fabiana imbricata shrubs. We monitored shrub recruitment and cover during nine postfire years in northwestern Patagonia grasslands and we studied the long-term population dynamics under different environmental conditions through a matrix model, exploring different fire frequencies and spring precipitation regimes. Both, the field monitoring and the model seem to confirm the relationships between shrub invasion and fire. The climate change forecast predicts an increase in the frequency of El Niño Southern Oscillation phenomena that could causes more coupled fires—rainy springs in northwestern Patagonia, and consequently, more recruitment windows for shrubs, like F. imbricata. The matrix model also indicates that this scenario would be the most favourable for shrub invasion. Our results contribute to the knowledge of the ecosystem properties and processes, providing useful information to improve the grasslands sustainable use.     

Variation in male sailfin molly, preference for female size: does sympatry with sexual parasites, drive preference for smaller conspecifics?

Male sailfin mollies (Poecilia latipinna) are sexually parasitized by gynogenetic Amazon mollies (Poecilia formosa). In areas of sympatry, Amazon mollies are frequently larger than female sailfin mollies. In sympatry, selection may favor males that prefer smaller conspecific mates (avoid mismating with Amazon mollies), or selection may favor males that prefer larger conspecific mates (higher fecundity). To explore this potential species and mate-quality recognition conflict, we examined male preference variation across populations. Males from one sympatric population showed stabilizing preference functions, whereas in another sympatric population, males showed directional preference functions. Variation across sympatric populations may be related to the length of time of co-evolution with Amazon mollies. In the allopatric populations, we found flat preference functions. Variation in male preferences could have important ramifications for the maintenance of Amazon mollies, as well as for the evolution of female size.     

Chicken manure biochar as liming and nutrient source for acid Appalachian soil

Acid weathered soils often require lime and fertilizer application to overcome nutrient deficiencies and metal toxicity to increase soil productivity. Slow-pyrolysis chicken manure biochars, produced at 350 and 700°C with and without subsequent steam activation, were evaluated in an incubation study as soil amendments for a representative acid and highly weathered soil from Appalachia. Biochars were mixed at 5, 10, 20, and 40 g kg into a Gilpin soil (fine-loamy, mixed, active, mesic Typic Hapludult) and incubated in a climate-controlled chamber for 8 wk, along with a nonamended control and soil amended with agronomic dolomitic lime (AgLime). At the end of the incubation, soil pH, nutrient availability (by Mehlich-3 and ammonium bicarbonate diethylene triamine pentaacetic acid [AB-DTPA] extractions), and soil leachate composition were evaluated. Biochar effect on soil pH was process- and rate-dependent. Biochar increased soil pH from 4.8 to 6.6 at the high application rate (40 g kg), but was less effective than AgLime. Biochar produced at 350°C without activation had the least effect on soil pH. Biochar increased soil Mehlich-3 extractable micro- and macronutrients. On the basis of unit element applied, increase in pyrolysis temperature and biochar activation decreased availability of K, P, and S compared to nonactivated biochar produced at 350°C. Activated biochars reduced AB-DTPA extractable Al and Cd more than AgLime. Biochar did not increase NO in leachate, but increased dissolved organic carbon, total N and P, PO, SO, and K at high application rate (40 g kg). Risks of elevated levels of dissolved P may limit chicken manure biochar application rate. Applied at low rates, these biochars provide added nutritional value with low adverse impact on leachate composition.     

Uptake, tissue distribution and metabolism of the insecticide endosulfan in Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

The study reports the accumulation, distribution and metabolism of technical endosulfan in Jenynsia multidentata. Adult females were exposed to acute sublethal concentrations (0.072, 0.288 and 1.4 μg L⁻¹). After 24 h, fish were sacrificed and gills, liver, brain, intestine and muscle were removed. Results show that both isomers of technical-grade endosulfan (α- and β-) are accumulated in fish tissues and biotransformation to endosulfan sulfate occurs at all concentrations tested. Significantly differences in endosulfan accumulation were only found at 1.4 μg L⁻¹ but not between the lowest concentrations. However a similar distribution pattern was observed at all exposure levels where liver, intestine and brain had the highest levels of α-, β-endosulfan and endosulfan sulfate. Moreover, liver and brain showed the highest endosulfan sulfate:α-endosulfan ratios due to high biotransfomation capacity. J. multidentata demonstrated to be a sensitive species under exposure to technical endosulfan and, therefore, could be used to assess aquatic pollution.     

Dignity and the right of internally displaced adolescents in Colombia to sexual and reproductive health

In Colombia, national policies and laws on the protection of vulnerable populations pay specific attention to the sexual and reproductive health needs and rights of internally displaced adolescents. This paper describes how a United Nations Population Fund (UNFPA)-supported programme (September 2000-August 2004) on the sexual and reproductive health of internally displaced adolescents contributed to restoring their dignity as a precursor to promoting their sexual and reproductive health rights. Different forms of the arts were used as basic techniques to discover their body and to provide sexual and reproductive health information and education. The arts were found to play a key role in restoring their dignity. Although dignity appeared to be a determinant of greater awareness of rights, it did not lead to increased empowerment with regard to rights. The availability of and access to sexual and reproductive health services remains a problem and displaced populations continue to have little or no power to hold their authorities accountable.     

Peak to Mean Pollutant Concentration Ratios for Various Terrain and Vegetation Cover

Many of the new particle sizing instruments utilize light scattering principles to detect and size aerosolparticles. The sensitivity of such nstruments is quite good, although extensive light shielding and focusingmethods must be used. A visible He-Ne gas laser cavity with its low gain is very sensitive to disturbances in its optical cavity and so may provide a new particle sizing approach.     

A contribution for the evaluation of the territorial impact of transport infrastructures in the early stages of the EIA: application to the Huelva (Spain)–Faro (Portugal) rail link

The Environmental Impact Assessment (EIA) procedure should predict and identify the major impacts of a project development that may cause specific spatial and temporal effects. Early in the EIA, the scoping stage provides all the relevant information on the impacts of the project alternatives. In particular, potential effects on the territorial network such as habitat connectivity loss and accessibility improvements should be taken into account in the various proposed layout alternatives when evaluating transport infrastructure projects. However, several authors have identified deficiencies in practice. The aim of this article is to provide a methodology for the assessment of these territorial impacts using adequate indicators in the early stages of the EIA procedure.

The proposed method is based on a comparison of a range of alternative layouts for a railway line linking two population centres, using indicators calculated with geographic information systems. The methodology was applied to a case study – the rail link between Huelva (Spain) and Faro (Portugal) – and the high speed rail (HSR) and conventional rail were evaluated in different layouts. The method was effective in spatially identifying significant impacts on accessibility improvements, which occurred closer to the cross border area. The conventional railway alternatives have similar accessibility values to the HSR. The results also reveal that connectivity loss is not limited to the area around the infrastructure, but extends throughout the territory. The results are at variance with the initiative proposed by Spanish and Portuguese transport decision-makers, and raise the possibility of selecting a conventional railway option. An adequate territorial evaluation methodology enables the new action to be correctly assessed, and supplies the information required to propose the most suitable alternative from a socio-economic and environmental standpoint, regardless of whether this proposal was initially included in the transport policy.     

Spatial variability of sediment ecotoxicity in a large storm water detention basin

Detention basins are valuable facilities for urban storm water management, from both the standpoint of flood control and the trapping of pollutants. Studies performed on storm water have shown that suspended solids often constitute the main vector of pollutants (heavy metals, polycyclic aromatic hydrocarbon (PAH), etc.). In order to characterise the ecotoxicity of urban sediments from storm water detention basins, the sediments accumulated over a 6-year period were sampled at five different points through the surface of a large detention basin localised in the east of Lyon, France. A specific ecotoxicological test battery was implemented on the solid phase (raw sediment) and the liquid phase (interstitial water of sediments). The results of the study validated the method formulated for the ecotoxicological characterization of urban sediments. They show that the ecotoxicological effect of the sediments over the basin is heterogeneous and greater in areas often flooded. They also show the relationship between, on one hand, the physical and chemical characteristics of the sediments and, on the other hand, their ecotoxicity. Lastly, they contribute to a better understanding of the dynamics of the pollution close to the bottom of detention basins, which can be useful for improving their design. The results of this research raise particularly the issue of using oil separators on the surface of detention basins.     

Metal mobilization in soil by two structurally defined polyphenols

Polyphenols including tannins comprise a large percentage of plant detritus such as leaf litter, and affect soil processes including metal dynamics. We tested the effects of tannins on soil metal mobilization by determining the binding stoichiometries of two model polyphenols to Al(III) and Fe(III) using micelle-mediated separation and inductively coupled plasma optical emission spectroscopy (ICP-OES). By fitting the data to the Langmuir model we found the higher molecular weight polyphenol (oenothein B) was able to bind more metal than the smaller polyphenol (epigallocatechin gallate, EGCg). For example, oenothein B bound 9.43 mol Fe mol^?1, while EGCg bound 4.41 mol of Fe mol^?1. Using the parameters from the binding model, we applied the Langmuir model for competitive binding to predict binding for mixtures of Al(III) and Fe(III). Using the parameters from the single metal experiments and information about polyphenol sorption to soils we built a model to predict metal mobilization from soils amended with polyphenols. We tested the model with three natural soils and found that it predicted mobilization of Fe and Al with r² = 0.92 and r² = 0.88, respectively. The amount of metal that was mobilized was directly proportional to the maximum amount of metal bound to the polyphenol. The secondary parameter in each model was the amount of weak organically chelated Fe or Al that was in the soil. This study provides the first compound-specific information about how natural polyphenols interact with metals in the environment. We propose a model that is applicable to developing phytochelation agents for metal detoxification, and we discuss how tannins may play a role in metal mobilization from soils.