CANOPY COVER AND SHADE DETERMINATIONS IN RIPARIAN ZONES1

ABSTRACT: Three instruments commonly used to measure stream canopy cover were evaluated: the clinometer, a modified spherical convex densiometer Model A, and a hemispherical image system. The hemispherical image system was also used to model shade. At each of five locations throughout Oregon, canopy cover above a stream was measured from the center of the stream along a series of transects. Vegetation along the reaches sampled ranged from a densely vegetated coastal forest stand to a sparsely vegetated eastern Oregon meadow. When techniques were compared within each site, canopy cover measured with the clinometer was similar to that measured with hemispherical imagery. The densiometer measurements, however, were typically lower than, though still highly correlated with, those derived from hemispherical images and from the clinometer. Because of site‐specific factors, the differences between all methods were significant in the Willamette and John Day Provinces. Canopy cover and shade were not equivalent for the streams studied.     

Female preferences based on male nutritional chemical traits

Selection favors females that attend to reliable information about male genetic quality and fitness. Male nutritional condition can be a significant sign of mate quality since poor nutrition can be related to reduced sperm quality, low sperm quantity, sexually transmitted diseases, and parasites. We tested whether female Nile tilapia, Oreochromis niloticus, preferred the chemical cues of males that were well fed with high-protein diet over those fed with low-protein diet. Females do not only discriminate between males but also show a preference for well-fed males, discriminating between the odors with respect to nutritional state, suggesting that they were responding to a food-specific chemical cue. It is therefore likely that nutritional condition is related to the production of pheromones in males. Our results suggest that information about male nutritional state can be conveyed in chemical cues and that females attend to these cues during mate choice.     

Making framing of uncertainty in water management practice explicit by using a participant-structured approach

By now, the need for addressing uncertainty in the management of water resources is widely recognized, yet there is little expertise and experience how to effectively deal with uncertainty in practice. Uncertainties in water management practice so far are mostly dealt with intuitively or based on experience. That way decisions can be quickly taken but analytic processes of deliberate reasoning are bypassed. To meet the desire of practitioners for better guidance and tools how to deal with uncertainty more practice-oriented systematic approaches are needed. For that purpose we consider it important to understand how practitioners frame uncertainties. In this paper we present an approach where water managers developed criteria of relevance to understand and address uncertainties. The empirical research took place in the Doñana region of the Guadalquivir estuary in southern Spain making use of the method of card sorting. Through the card sorting exercise a broad range of criteria to make sense of and describe uncertainties was produced by different subgroups, which were then merged into a shared list of criteria. That way framing differences were made explicit and communication on uncertainty and on framing differences was enhanced. In that, the present approach constitutes a first step to enabling reframing and overcoming framing differences, which are important features on the way to robust decision-making. Moreover, the elaborated criteria build a basis for the development of more structured approaches to deal with uncertainties in water management practice.     

Valuing biodiversity attributes and water supply using choice experiments: a case study of La Campana Peñuelas Biosphere Reserve, Chile

The main objective of this study is to assess public economic preferences for biodiversity conservation and water supply and to analyse the factors influencing those preferences. A survey based on the choice experiment method was carried out at Peñuelas National Reserve, Chile, an area that is threatened by both occasional forest fires and the growing housing market. The input of local administrators was used to define environmental attributes of the area related to biodiversity conservation and water supply. Attributes were selected for analysis by the choice experiment. The selected attributes were the following: existence of endemic orchid species, chances of observing animals with scenic attraction, additional protection for an endemic amphibian, and availability of drinkable water in the future. A monetary variable consisting of an increase in the rate for entry to the area was also incorporated to estimate willingness to pay (WTP) for additional protection for the selected attributes. Three hundred four Chilean visitors to the reserve were randomly selected for interviews. Econometric analysis based on the Theory of Utility Maximization shows that visitors are willing to pay to protect the selected attributes. WTP values for the attributes range from CHP $2,600 ($5.4) to $6,600 ($14) per person per visit. The results of this research provide reserve managers information about tradeoffs that could be used to enhance public support and maximise the social benefits of nature conservation management programmes.     

Phylogeography of the European stalked barnacle (Pollicipes pollicipes): identification of glacial refugia

The alternation of glacial and interglacial events during the Pleistocene has produced changes in species distribution ranges leading to bottlenecks and alterations of patterns of gene flow. The European stalked barnacle, Pollicipes pollicipes, is a sessile pedunculate cirripede that inhabits the rocky intertidal frame, from Senegal to the northwestern coast of France. In this work, we have analyzed a fragment of the mitochondrial gene cytochrome c oxidase subunit I for 569 individuals of P. pollicipes in order to investigate whether the shifts in climatic conditions that occurred during the Pleistocene influenced the current pattern of distribution of genetic variation of P. pollicipes. A pre-last glacial maximum pattern of demographic expansion was found, in concordance with many other North Atlantic marine species. On the other hand, three potential glacial refugia were identified: North African coasts, northwestern Iberian Peninsula and English Channel/Brittany.     

Outcome of fetal echogenic bowel: A systematic review and meta-analysis

The main aim of this systematic review was to explore the outcome of fetuses with isolated echogenic bowel (EB) on antenatal ultrasound. Inclusion criteria were singleton pregnancies with isolated EB no associated major structural anomalies at the time of diagnosis. The outcomes observed were: chromosomal anomalies, cystic fibrosis (CF), associated structural anomalies detected only at follow-up scans and at birth, regression during pregnancy, congenital infections, intra-uterine (IUD), neonatal (NND) and perinatal (PND) death. Twenty-five studies (12 971 fetuses) were included. Chromosomal anomalies occurred in 3.3% of the fetuses, mainly Trisomy 21 and aneuploidies involving the sex chromosomes. Cystic fibrosis occurred in 2.2%. Congenital infections affected 2.2%, mainly congenital Cytomegalovirus (CMV) infection. The majority of fetuses with EB experienced regression or disappearance of the EB at follow-up scans. Associated anomalies were detected at a follow-up scan in 1.8%. Associated anomalies were detected at birth and missed at ultrasound in 2.1% of cases. IUD occurred in 3.2% of cases while the corresponding figures for NND and PND were 0.4% and 3.1%. Fetuses with EB are at increased risk of adverse perinatal outcome, highlighting the need for a thorough antenatal management and postnatal follow-up. Assessment during pregnancy and after birth should be performed in order to look for signs of fetal aneuploidy, congenital infections and associated structural anomalies.     

Socio-economic levels and environmental perception in a small town in Argentina

Summary In order to determine the environmental problems as perceived by the community of Luján (Province of Buenos Aires, Argentina), a survey was carried out. The relationship between environmental perception and socio-economic level was also studied. The most important problems reported by the community were the floods, which occur when the Luján river overflows its banks, and the contamination of this river as it flows through Luján city. Deficiencies in the tourist infrastructure were also considered to be serious. The least perceived problem was that of industrial air pollution. Positive correlations between environmental perception, socio-economic standing and levels of instruction were observed.Claudia Feijoó is a Lecturer in Ecology at the National University of Luján. Her research interests are in environmental perception and ecology of rivers and polluted waters. Prof. Fernando Momo is Professor of Ecology at the same University. His research interests are focused on theoretical ecology and ecological modelling, especially as applied to aquatic ecology.     

Land Use Change on Coffee Farms in Southern Guatemala and its Environmental Consequences

Changes in commodity prices, such as the fall in coffee prices from 2000 to 2004, affect land use decisions on farms, and the environmental services they provide. A survey of 50 farms showed a 35 % loss in the area under coffee between 2000 and 2004 below 700 m with the majority of this area (64 %) being coffee agroforest systems that included native forest species. Loss of coffee only occurred on large and medium-scale farms; there was no change in area on cooperatives. Coffee productivity declined below 1,100 m altitude for sun and Inga shade coffee, but only below 700 m altitude for agroforest coffee. Coffee productivity was 37–53 % lower under agroforests than other systems. Increases in rubber and pasture were related to low altitude large-scale farms, and bananas and timber plantations to mid-altitude farms. Average aboveground carbon stocks for coffee agroforests of 39 t C ha^?1 was similar to rubber plantations, but one-third to one half that of natural forest and timber plantations, respectively. Coffee agroforests had the highest native tree diversity of the productive systems (7–12 species ha^?1) but lower than natural forest (31 species ha^?1). Conversion of coffee agroforest to other land uses always led to a reduction in the quality of habitat for native biodiversity, especially avian, but was concentrated among certain farm types. Sustaining coffee agroforests for biodiversity conservation would require targeted interventions such as direct payments or market incentives specifically for biodiversity.     

Factors and Actors in Climate Change Mitigation: A Tale of Two South African Cities

Abstract

South Africa, being a developing nation, is faced with many challenges, including poverty and one of the world's highest HIV/AIDS infection rates. It is within this context that this paper presents an overview of the role played by major stakeholders in climate change mitigation policies, with the focus on two South African cities, namely Cape Town and Johannesburg. This paper aims to identify the internal and external factors that act as barriers to, or promote, climate change mitigation policy development and implementation in South African cities. These may take the form of the city's internal structures, political interventions and support, and external factors including partnerships with outside organizations, including all tiers of government, non-governmental organizations and academic institutions. The media and an energy crisis in the Cape prove to play an unexpected role in assisting Cape Town to implement climate change mitigation measures.