Vegetation Composition,Dynamics, and Management of a Bracken–Grassland and Northern–Dry Forest Ecosystem

We investigated differences in vegetation composition and dynamics for two globally rare ecosystems, bracken–grasslands and northern–dry forests of northern Wisconsin. These ecosystems commonly have been viewed as degraded pine barrens. Bracken–grasslands contained a high dominance of exotic species, low native richness, and no obvious prairie species, suggesting logging-era anthropogenic origins. Differences in cover for common plants among ecosystems were examined using Mann-Whitney U tests of equivalence. Cover of all 8 graminoid species, 4 of 5 Ericaceae and Myricaceae species, and 10 of 17 species of forbs were significantly different between ecosystems. Vegetation changes over a 4-year period were examined through detrended correspondence analysis (DCA) and analysis of variance (ANOVA) repeated measures. DCA analyses of community composition failed to detect significant temporal trends within individual management units, although differences were apparent between ecosystems, regardless of sample year. In addition, no apparent patterns could be detected between years when comparing dominant individual species to management history (prescribed fire). This is contrary to what would be expected for a degraded pine barrens and questions the efficacy of using repeated prescribed fire as a management tool in bracken–grasslands. Methods for conservation and restoration of xeric ecosystems of northern Wisconsin have historically relied heavily on single species (e.g., sharp-tailed grouse) wildlife models, without full consideration of other factors. We suggest that stakeholders involved in these restoration projects examine historic processes and reference conditions prior to formulating management goals. Greater attention to the differentiation and individual management needs of pine barrens, northern–dry forests, and bracken–grasslands is needed.     

Beyond the environmental Kuznets curve: Do combined impacts of air transport and rail transport matter for environmental sustainability amidst energy use in E7 economies?

Environment, Development and Sustainability - This study is motivated by the United Nations Sustainable Development Goals (UN-SDG-7,8,11,12 and 13) on the need for clean and responsible energy...     

Havana's popular gardens:sustainable prospects for urban agriculture

With the collapse of the Soviet Bloc and its economic support in 1989, as well as the tightening of the US economic embargo, Cuba has been forced to explore sustainable agriculture as a source of food security. This paper examines Havana's popular gardens, an important feature in Cuba's recent emphasis on self-reliant agriculture. Popular gardens are small plots of state-owned land that have been promoted since 1991 throughout Havana and other Cuban cities in response to recent food shortages. The popular gardens are a unique form of socialist agriculture which offer valuable insight into urban food production during economic crisis. They have emerged in the absence of land markets, with active government support and with widespread community organization and participation. The continued success of the gardens, however, is contingent on underlying political and economic factors.     

First-trimester aneuploidy screening using serum human chorionic gonadotropin (hCG), free ahCG,and progesterone

Immunochemical serum assays for human chorionic gonadotropin (hCG), the free ohCG subunit, and progesterone (P) were considered separately and in combination for their ability to screen for chromosomally abnormal pregnancies in the first trimester. Maternal serum was collected from 141 women undergoing chorionic villus sampling at 9–12 menstrual weeks. Trisomy 21 pregnancies had significantly higher hCG levels, while trisomy 18 and 13 pregnancies had markedly lower hCG and progesterone levels than those of chromosomally normal pregnancies. However, the discrimination of normal from aneuploid pregnancies was poor with either hCG alone, progesterone alone, or free ahCG alone. Much improved discrimination was obtained by combining hCG, free ahCG, and P into an aneuploidy index [(P/hCG)(free ahCG/hCG)]. This index distinguished 9 out of 17 (53 per cent) of the trisomy 21 pregnancies, while only misidentifying 5 out of 112 (4.5 per cent) of the normal pregnancies. The aneuploidy index thus appears promising as a first-trimester biochemical screen for aneuploid pregnancies.     

Potter's syndrome in the second trimester—prenatal screening and pathological findings in 60 cases of oligohydramnios sequence

Fifty-two second-trimester and eight third-trimester (>28/40) autopsies with clinical or pathological evidence of oligohydramnios sequence (“Potter's syndrome”) were reviewed. Twenty-eight cases had renal anomalies (71 per cent in terminations following prenatal ultrasound), 27 had no renal malformation (35 per cent with chorioamnionitis), and five had external assessments only. In 15 cases, the renal lesion was part of a multiple malformation syndrome. Seven cases had a lesion which either recurred in a sibling in the same family or was a recognized autosomal recessive syndrome. Three cases had an abnormal karyotype, two of which had renal anomalies. Maternal serum alpha-fetoprotein (AFP) did not discriminate between cases with renal malformations and those without. Pulmonary hypoplasia was commoner in third-trimester than in second-trimester cases. External appearance and absent umbilical artery were not reliable predictors of underlying internal anomalies. These findings reflect the shift from postnatal to prenatal diagnosis in modern practice. In this series, mainly second-trimester cases, 50 per cent of cases had no malformations, in a condition which is traditionally associated with renal disease. The high incidence of chorioamnionitis suggests that the mechanism of oligohydramnios is occult amniotic fluid leakage. Prenatal diagnosis of oligohydramnios in the second trimester is dependent on ultrasound scanning and a full post-mortem examination is necessary to identify any underlying fetal cause.     

Desertification,and climate change: the case for greater convergence

Poor knowledge of links between desertification and globalclimate change is limiting funding from the Global Environment Facility foranti-desertification projects and realization of synergies between theConvention to Combat Desertification (CCD) and the FrameworkConvention on Climate Change (FCCC). Greater convergence betweenresearch in the two fields could overcome these limitations, improve ourknowledge of desertification, and benefit four areas of global climate changestudies: mitigation assessment; accounting for land cover change in thecarbon budget; land surface-atmosphere interactions; and climate changeimpact forecasting. Convergence would be assisted if desertification weretreated more as a special case in dry areas of the global process of landdegradation, and stimulated by: (a) closer cooperation between the FCCCand CCD; (b) better informal networking between desertification and globalclimate change scientists, e.g. within the framework of theIntergovernmental Panel on Climate Change (IPCC). Both strategies wouldbe facilitated if the FCCC and CCD requested the IPCC to provide ascientific framework for realizing the synergies between them.     

Miscanthus × Giganteus straw and pellets as sustainable fuels

In this paper we present, for the first time, data on the combustion of Miscanthus × Giganteus straw and pellets. We found that the heating value of Miscanthus is 17.744 MJ/kg. The gaseous emission indices of SO₂, NO _x and total organic carbon (TOC) in the exhaust are reported and compared with the European standards for biomass boilers. On the basis of our results, it is possible to evaluate a net energy yield between 152 and 326 MJ/hectare/year for the cultivation of Miscanthus with an energy balance estimated to be in the range of 7.7–15.4. According to the presented results, it seems reasonable to consider Miscanthus as a promising candidate as alternative fuel.     

Exvessel Price Determination in the Alaska King Crab Fishery: A Formula Price Contract under Uncertainty?

Commercial fisheries industry structure often suggests exvessel price formation occurs in the context of a competitive harvesting sector and an oligopsonistic processing sector. However, industry conduct leading to a determination of exvessel price can be notably at odds with this inference. This paper presents empirical evidence that the conduct of at least one such fishery, the Alaska king crab industry, may emulate bilateral monopoly. Exvessel price determination is consistent with an implicit formula price contract in which fishers behave as monopolists through bargaining associations, while processors behave as countervailing monopsonists, even in the absence of explicit collusion. Both sectors appear to behave in a manner consistent with joint expected profit maximization, with profit shares apportioned via the implicit formula price contract. This price formation process simplifies empirical analysis of the bilateral monopoly conduct by avoiding complicated game theoretic/bargaining models.     

Geographic Analysis of California Condor Sighting Data

Observation and habitat data were compiled and analyzed in conjunction with recovery planning for the endangered California Condor ( Gymnogyps californianus ). A geographic information system (GIS) was used to provide a quantitative inventory of recent historical Condor habitats, to measure the association of Condor activity patterns and mapped habitat variables, and to examine spatio-temporal changes in the range of the species during its decline. Only five percent of the study area within the historic range is now used for urban or cultivated agricultural purposes. Observations of Condor feeding perching, and nesting were nonrandomly associated with mapped land cover, in agreement with life history information for the species. The precipitous decline in numbers of Condors in this century produced only a small reduction in the limits of the observed species' range, as individual birds continued to forage over most of the range. Some critical risk factors such as shooting and lead poisoning are difficult to map and have not been included in the database. Besides the applications demonstrated in this case study, GIS can be a valuable tool for recovery planning, in the design of stratified sampling schemes, or for extrapolation of habitat models over unsurveyed regions. We conclude with recommendations from this case study regarding when to consider using GIS and the importance of pilot studies and sensitivity analysis.