Projecting landscape changes in southern Chile: Simulation of human and natural processes driving land transformation

We describe a simulation model representing the most important human and natural factors driving land use and cover changes (LUCC) in southern Chile. We evaluate the model by examining its ability to simulate LUCC observed over the past three decades, conduct a sensitivity analysis of simulated trends to changes in important model parameters, and use the model to project likely landscape transformations over the next decade under “as usual,” “pessimistic,” and four “optimistic” scenarios. The model consists of five submodels representing LUCC on two distinct soil formations (volcanic ash and gleysols) and four major land use categories: native forest, agricultural land, shrubland, and urban land. Land use and cover sub-categories include old growth forests, secondary forests, and low and flooded shrubland. The model simulated well general historic trends in forest cover, agricultural land, shrubland, and urban land: from a forest-dominated landscape in 1976 to a landscape dominated by shrubland and agricultural land by 2007. Forest loss, forest degradation by logging and clearing for agriculture were the most important direct drivers of LUCC: forest logging and clearing were most important from 1976 to 1985, whereas after 1985 logging for firewood, driven by population growth, was most important. Sensitivity analysis indicated that model projections of general trends in the main land use and cover categories were not overly sensitive to changes in important model parameters, although further study is necessary to improve our estimates of the proportion of pasture requirements supplied by clearing low shrubland. Projections of LUCC suggested that a reduced amount of secondary forest would be left by 2017 if no actions are taken to reduce forest loss (“as usual”). Increasing population (“pessimistic scenario”) resulted in similar trajectories than those predicted by the as usual scenario, whereas reducing logging for firewood and increasing forest recruitment from shrubland could reduce loss of native forest by nearly one-third (“optimistic scenarios”). Surprisingly, shrubland exhibited the most complex and influential dynamics in all scenarios, being the immediate outcome of forest loss and the main long-term source of land for agriculture, urban expansion, and forest recovery. Few studies in Chile, or elsewhere, have considered the importance of this intermediate successional stage. Of the scenarios simulated, financial incentives targeted toward channeling shrubland into regenerated forest seemed most promising, although obstacles to such a management strategy exist.     

Hand anthropometric study in northern Colombia

The main purpose of this study is to gather information about the dimensions of the northern Colombian (Caribbean region) population, focusing on the dimensions of the hand and comparing them with measurements from other regions. Thirty-two hand dimensions were chosen and 120 males and 86 females were measured. Results indicated that there were differences between the dimensions of the hand for men and women, showing that men are larger. Also, there was a comparison made between some measurements of other studies in different regions of Colombia, the USA, Chile, Jordan, Korea and Japan. The results indicated important physiological differences between regions in Colombia and across countries. It was therefore concluded that differences in anthropometric measurements must be included in the design and procurement of machinery and apparatus in order to avoid productivity loss, occupational injuries or illness.     

Exploring Public Perception of Non-native Species from a Visions of Nature Perspective

Not much is known about lay public perceptions of non-native species and their underlying values. Public awareness and engagement, however, are important aspects in invasive species management. In this study, we examined the relations between the lay public’s visions of nature, their knowledge about non-native species, and their perceptions of non-native species and invasive species management with a survey administered in the Netherlands. Within this framework, we identified three measures for perception of non-native species: perceived risk, control and engagement. In general, respondents scored moderate values for perceived risk and personal engagement. However, in case of potential ecological or human health risks, control measures were supported. Respondents’ images of the human–nature relationship proved to be relevant in engagement in problems caused by invasive species and in recognizing the need for control, while images of nature appeared to be most important in perceiving risks to the environment. We also found that eradication of non-native species was predominantly opposed for species with a high cuddliness factor such as mammals and bird species. We conclude that lay public perceptions of non-native species have to be put in a wider context of visions of nature, and we discuss the implications for public support for invasive species management.     

Disturbance, Diversity, and Invasion: Implications for Conservation

Disturbance is an important component of many ecosystems, and variations in disturbance regime can affect ecosystem and community structure and functioning. The "intermediate disturbance hypothesis" suggests that species diversity should be highest at moderate levels of disturbance. However, disturbance is also known to increase the invasibility of communities. Disturbance therefore poses an important problem for conservation management, Here, we review the effects of disturbances such as fire grazing, soil disturbance and nutrient addition on plant species diversity and invasion with particular emphasis on grassland vegetation. Individual components of the disturbance regime can have marked effects on species diversity, but it is often modifications of the existing regime that have the largest influence. Similarly, disturbance can enhance invasion of natural communities, but frequently it is the interaction between different disturbances that has the largest effect. The natural disturbance regime is now unlikely to persist within conservation areas since fragmentation and human intervention have usually modified physical and biotic conditions. Active management decisions must now be made on what disturbance regime is required and this requires decisions on what species are to be encouraged or discouraged.     

Minute chromatin structures in cells of amniotic fluid—an interpretative dilemma

Single copies of tiny chromosome fragments, appearing either as single or as double minutes, were observed in a high frequency in amniotic fluid cultures of five mothers who underwent prenatal testing because of advanced age. In four cases, the minutes had arisen de novo. The minutes were later confirmed in fetal skin following termination of pregnancy in one case; in another, in cord blood following the birth of a normal boy; and in the third, in peripheral blood of a normal 3-year-old girl. In the fourth case, the minutes were not confirmed in cord blood following the birth of a normal boy. A follow-up chromosome study of the baby boy in the fifth case was not possible but the minutes were maternally transmitted.     

An Evaluation of Daumod Model in Estimating Urban Background Concentrations

This article presents an evaluation of the performance of the urban atmospheric dispersion model (DAUMOD) in estimating nitrogen oxides (NO_x) background concentrations in Copenhagen. Estimations of hourly average (averaged over a year), mean daily and mean monthly concentrations of NO_x are compared with observed values for two years of data. The model slightly underestimates low hourly average values and overestimates high values. The cumulative frequency distribution of mean daily concentration obtained from model estimations is in good agreement with the obtained from observed data. We performed a statistical analysis to determine the agreement between estimated and observed concentration values. The results show that 95.8% of hourly average estimations, 86.8% of mean daily and 100% of monthly average concentrations are within a factor of two of the observed values. The normalised mean square error of predictions is +0.13 for hourly average estimations, +0.22 for mean daily values and +0.02 for monthly mean concentrations. The fractional bias values are: –0.049 for hourly mean estimations, –0.047 for mean daily values and –0.053 for monthly average estimations. The values of the statistical parameters allow us to consider that though estimations are lightly larger than the observed values, the model performance is acceptable.     

Immunotoxicity of carbon black nanoparticles to blue mussel hemocytes

The potential for human and ecological toxicity associated with nanomaterials is a growing area of investigation. In mammalian cells, nanoparticles have been shown to induce inflammation and oxidative stress, and changes in cell signalling and gene expression. As the nanotechnology industries increase production, nanoscale products and by products will enter the aquatic environment, posing a possible threat to aquatic organisms. In particular, filter-feeding organisms may represent a unique target group for nanoparticle toxicology. In this work, the effects of commercial nanosized carbon black (NCB) on the immune cells, the hemocytes, of the bivalve mollusc Mytilus, and the possible mechanisms involved were investigated. The results demonstrate that NCB (1, 5, and 10 microg/ml), did not induce significant lysosomal membrane destabilization, as evaluated by the NR retention time assay. A concentration-dependent uptake of NCB by hemocytes was observed and it was associated by a rapid increase in extracellular lysozyme release, extracellular oxyradical production, and nitric oxide (NO) release. Moreover, at the highest concentration tested, NCB induced significant changes in mitochondrial parameters (decrease mitochondrial mass/number and membrane potential), as evaluated by flow cytometry. The effects of NCB were mediated by rapid activation of the stress-activated MAPKs (Mitogen Activated Protein Kinases) p38 and JNKs, that play a key role in immune and inflammatory responses. The results demonstrate that in mussel hemocytes like in mammalian cells NCB exposure can induce inflammatory processes, and indicate that bivalve immunocytes can represent a suitable model for investigating the effects and modes of action of nanoparticles in the cells of aquatic invertebrates.     

Scale-dependent analysis of an otter–crustacean system in Argentinean Patagonia

The Southern river otter or ‘huillin’, Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin’s distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north–south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink (Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible.     

Barriers to the long‐term recovery of individuals with disabilities following a disaster

This study examines how pre‐existing disabling conditions influenced the recovery process of survivors of Hurricane Katrina. It focuses specifically on the barriers that hindered the recovery process in these individuals. Focus groups were convened in four Gulf Coast states with 31 individuals with disabilities who lived in or around New Orleans, Louisiana, prior to Hurricane Katrina in August 2005. Qualitative data were analysed using grounded theory methodology. Five themes emerged as the most significant barriers to recovery: housing; transportation; employment; physical and mental health; and accessing recovery services. While these barriers to recovery were probably common to most survivors of the disaster, the research results suggest that disability status enhanced the challenges that participants experienced in negotiating the recovery process and in acquiring resources that accommodated their disabilities. The findings indicate that, when disaster recovery services and resources did not accommodate the needs of individuals with disabilities, recovery was hindered. Recovery efforts should include building accessible infrastructure and services that will allow for participation by all.