An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain

Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts, there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species. Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management. In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of species are found in at least one protected area. According to respondents, the most frequently managed species are the most widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority of respondents stated that management measures are insufficient to control alien plants due to limited economic resources, lack of public awareness and support, and an absence of coordination among different public administrations. Managers also expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants rather than with specific cost-efficient strategies to manage alien species.     

Good deposits are not enough: Mining labor productivity analysis in the copper industry in Chile and Peru 1992–2009

Chile and Peru produce almost 45% of world’s mine copper output. This situation reflects their natural endowment and mining tradition, but is also the result of development processes undertaken over the last decades. As a result, both countries multiplied its mine copper production in more than 3 times in the last 20 years. Mining labor productivity played a central role achieving these amazing growth rates. Although there is a consensus about the relevance of this variable for the mining industry, the specific factors behind labor productivity changes are not completely understood.     

Assessment of trace metals and porphyrins in excreta of Humboldt penguins (Spheniscus humboldti) in different locations of the northern coast of Chile

To add data on trace metal contamination of Humboldt penguins in the South Pacific, levels of trace metals (As, Hg, Pb, Cu, Zn, and Cd) and porphyrins (copro-, uro-, and proto-) in excreta of Humboldt penguins that inhabit some important nesting sites on the northern coast of Chile were determined. Fresh excreta were collected on Pan de Azúcar Island, Chañaral Island, and Cachagua Island, from December 2011 to January 2012. Concentration of metals was determined by flame atomic absorption spectrophotometry, whereas porphyrins levels were measured by fluorimetric analysis. Concentrations (dry weight) of Cu (199.67 μg g^?1), As (7.85 μg g^?1), and Pb (12.78 μg g^?1) were higher (p?≤?0.05) in Cachagua Island. Colonies from Pan de Azúcar Island showed the highest levels of Hg (0.76 μg g^?1), Cd (47.70 μg g^?1), and Zn (487.10 μg g^?1). Samples from Cachagua Island showed the highest (p?≤?0.05) levels of copro- (2.16 nmol g^?1), uro- (2.20 nmol g^?1), and protoporphyrins (2.23 nmol g^?1). There was a positive correlation between the metals As, Pb, and Cu with uro-, copro-, and protoporphyrins. The results indicated that penguin colonies from Cachagua Island are more exposed to metal contamination than penguin colonies from Pan de Azúcar and Chañaral Islands, thus being more likely to develop certain diseases caused by contamination with metals. Considering biomagnification, the metals detected in the excreta of Humboldt penguins can be a source of contamination from marine environments to terrestrial ecosystems, which could also affect other living organisms.     

Using exploration expenditures to assess the climate for mineral investment

Countries that rely on private investors to find and exploit their mineral resources need reliable indicators of their investment attractiveness. This study explores the use of exploration expenditures for this purpose, focusing primarily on Chile.     

Life-history variation in three coexisting cheilostome bryozoan species of the genus Stylopoma in Panamá

Life-history variation was studied in three sympatric species of Stylopoma Levinsen [S. spongites (Pallas), S. projecta Canu and Bassler and Stylopoma n. sp. 15] in Panamá. Bryozoan colonies were collected from 27 reefs along 300 km of the Caribbean coast of Panamá. The distribution and abundance of each species were very patchy, but with broad overlap in occurrence among localities and depths. Nevertheless, species differed considerably in colony size, size at first reproduction and numbers of brooding larvae; implying that interspecific differences in life-history traits may contribute to their coexistence. To examine closely this variation in life-history patterns, we grew, in a common garden experiment, the offspring of the two most common species that were obtained from parent colonies collected from several reefs. There were highly significant differences in growth rates and the timing and extent of sexual reproduction which corresponded well to patterns observed in individuals from the field. Other factors, including size of larvae, extent of secondary zooidal calcification and numbers of avicularia were also correlated with differences in life histories. Despite this additional complexity, however, ecological consequences of trade-offs in life history among modular species such as Stylopoma spp. appear very similar to those among unitary species.     

N and P dynamics in the litter layer and soil of Mexican semi-arid forests, state of Morelos

In central Mexico, it is common for farmers to retain useful trees in abandoned lands after maize cultivation, creating a park-like landscape of scattered trees for extensive livestock grazing, among other land uses (mature forests, secondary forests, and livestock grazing in secondary forests). Among these trees Acacia cochliancantha and Ipomoea arborescens are the most common species associated with this land use in the region. The objective of this study was to assess the effects of both tree species on soil N and P recycling. To this end, we measured N and P concentrations in leaves of both species; and the seasonal N and P (total and dissolved) content in the litter, and total N and P, inorganic N, and bicarbonate-extractable-P concentrations, and the N transformations in the soil, in samples collected under crown of Acacia and Ipomoea and in open areas. Trees of different species varied in their capacity to cycle N. The leaves of Acacia were richer in N than those of Ipomoea (29.7 and 25.0 mg N g⁻¹, respectively), and nutrient resorption was higher in leguminous trees than in Ipomoea (by 20% in the case of N, and 35% in the case of P). Acacia trees had higher effects on soils than Ipomoea trees, like consistent increases of N concentrations (by 30% in the case of total N, and by 50% in the case of inorganic N) and transformations (N mineralization and nitrification in rainy season increases by a factor of 20 and 36, respectively). On the other hand, Ipomoea produced senescent leaves and accumulated forest litter with less P concentration (0.8 and 0.7 mg P g⁻¹, respectively) in relation to Acacia (senescent leaves: 1.3 mg P g⁻¹; litter: 1.1 mg P g⁻¹), reflecting the lower availability of the nutrient in the soil. The total litter N and P pools decreased in the rainy season under crown of both species, as the dissolved P pool did. The total soil N and P concentrations did not change with sampling season. However, potential N transformations and bicarbonate P under both species were higher in dry season than in rainy season samples. Comparison with other land uses in the region suggests that the Acacia–Ipomoea system cycles low quantity of nutrients, but there are no notable differences in the availability of P in the soils. These results demonstrate that scattered trees improve the N and P cycling following the discontinuation of agricultural practices, and the effects will vary depending on the tree species.     

Adsorption behavior of 2,4-dichlorophenol and pentachlorophenol in an allophanic soil

The adsorption of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) by a variable-charge soil from southern Chile was studied in a series of batch equilibration experiments. 2,4-DCP and PCP adsorption behavior was evaluated as a function of pH (pH values of 4.5, 6.0 and 7.5) in a 0.1M KCl (25 degrees C) background solution for soil material collected at three different depths (0-20 cm, 20-40 cm, and 40-60 cm). 2,4-DCP and PCP adsorption decreased with increasing soil pH, suggesting that the undissociated species were adsorbed more readily and that electrostatic repulsion may inhibit partitioning as pH increases. The PCP adsorption was greater than observed for 2,4-DCP and decreased with soil depth. Multiple regression analysis between K(d) and various soil properties indicated that the soil organic carbon content is a strong indicator of chlorophenol adsorption, and in addition to organic carbon, the soil pH is an important property controlling adsorption behavior.     

Lateral flow assay applied to pesticides detection: recent trends and progress

Environmental Science and Pollution Research - Devices based on lateral flow assay (LFA) have been gaining more and more space in the detection market mainly due to their simplicity, speed, and low...