玛曲县土地利用/覆盖变化对区域生态系统服务价值的影响

运用GIS和遥感技术分析了玛曲县1975、1990和2005年的土地利用/覆盖特征,在此基础上使用生态价值系数(C)计算出该县生态系统服务价值.结果表明,该区域1975~2005年间生态系统服务价值从129.713亿元减少到123.961亿元,共损失5.75亿元,且损失量和损失幅度呈持续增加趋势;该区域生态系统服务价值中,废物处理价值最高,气候调节价值次之,原材料价值最低,且30年间各服务类型的价值均呈减小趋势;玛曲县1975、1990和2005年人均生态系统服务价值分别为58.96,42.80,29.51万元,表明玛曲县由于人口的增长,环境压力呈持续增大趋势.草地和湿地退化是导致该区域生态系统服务价值减少的主要原因.CS检验说明本研究所选C值较为合理.     

Modeling the impacts of hunting on the population dynamics of red howler monkeys (Alouatta seniculus)

Overexploitation of wildlife populations occurs across the humid tropics and is a significant threat to the long-term survival of large-bodied primates. To investigate the impacts of hunting on primates and ways to mitigate them, we developed a spatially explicit, individual-based model for a landscape that included hunted and un-hunted areas. We used the large-bodied neotropical red howler monkey (Alouatta seniculus) as our case study species because its life history characteristics make it vulnerable to hunting. We modeled the influence of different rates of harvest and proportions of landscape dedicated to un-hunted reserves on population persistence, population size, social dynamics, and hunting yields of red howler monkeys. In most scenarios, the un-hunted populations maintained a constant density regardless of hunting pressure elsewhere, and allowed the overall population to persist. Therefore, the overall population was quite resilient to extinction; only in scenarios without any un-hunted areas did the population go extinct. However, the total and hunted populations did experience large declines over 100 years under moderate and high hunting pressure. In addition, when reserve area decreased, population losses and losses per unit area increased disproportionately. Furthermore, hunting disrupted the social structure of troops. The number of male turnovers and infanticides increased in hunted populations, while birth rates decreased and exacerbated population losses due to hunting. Finally, our results indicated that when more than 55% of the landscape was harvested at high (30%) rates, hunting yields, as measured by kilograms of biomass, were less than those obtained from moderate harvest rates. Additionally, hunting yields, expressed as the number of individuals hunted/year/km², increased in proximity to un-hunted areas, and suggested that dispersal from un-hunted areas may have contributed to hunting sustainability. These results indicate that un-hunted areas serve to enhance hunting yields, population size, and population persistence in hunted landscapes. Therefore, spatial regulation of hunting via a reserve system may be an effective management strategy for sustainable hunting, and we recommend it because it may also be more feasible to implement than harvest quotas or restrictions on season length.     

Ranking individual habitat patches as connectivity providers: Integrating network analysis and patch removal experiments

Here we propose an integrated framework for modeling connectivity that can help ecologists, conservation planners and managers to identify patches that, more than others, contribute to uphold species dispersal and other ecological flows in a landscape context. We elaborate, extend and partly integrate recent network-based approaches for modeling and supporting the management of fragmented landscapes. In doing so, experimental patch removal techniques and network analytical approaches are merged into one integrated modeling framework for assessing the role of individual patches as connectivity providers. In particular, we focus the analyses on the habitat availability metrics PC and IIC and on the network metric Betweenness Centrality. The combination and extension of these metrics jointly assess both the immediate connectivity impacts of the loss of a particular patch and the resulting increased vulnerability of the network to subsequent disruptions. In using the framework to analyze the connectivity of two real landscapes in Madagascar and Catalonia (NE Spain), we suggest a procedure that can be used to rank individual habitat patches and show that the combined metrics reveal relevant and non-redundant information valuable to assert and quantify distinctive connectivity aspects of any given patch in the landscape. Hence, we argue that the proposed framework could facilitate more ecologically informed decision-making in managing fragmented landscapes. Finally, we discuss and highlight some of the advantages, limitations and key differences between the considered metrics.     

A new approach to the analysis of adjacencies: Potentials for landscape insights

Spatial adjacencies are a key-issue in environmental studies. Adjacency effects have been amply observed for biotic (plants and animals) and abiotic components of ecosystems. Particularly well-documented are the effects from human manufactures onto the contiguous vegetation mosaics of natural and semi-natural areas.In this work we first propose and reformulate association rules analysis (ARA), a relatively new data mining algorithm with very limited scientific applications so far, in the form of an in-depth investigation method of the spatial pattern of landcover and vegetation maps. We applied ARA to two very different study areas in Northern Italy, the first (Ceno valley) having a substantial human footprint and mapped at 1:25,000 scale, the second (Foses valley) being almost natural and mapped at 1:5000 scale.We were able to: (a) detect the entire network of spatial adjacencies among landcover types and (b) quantify the frequency and strength of detected adjacencies. Based on our spatial analysis, we also advanced hypotheses on both natural and man-driven vegetation dynamics. In addition, ARA allowed us to propose an index of naturality based on the discovered contiguities.Results show the skill of the proposed approach to characterize landcover spatial patterns for both mid-resolution and high-resolution maps. Furthermore the proposed approach bears a general interest, since it can be applied to the analysis of any landcover map.     

Assessment of enrichment,geo-accumulation and ecological risk of heavy metals in surface sediments of the Msimbazi mangrove ecosystem,coast of Dar es Salaam,Tanzania

Results of the assessment of enrichment, accumulation and the ecological risk associated with three heavy metals (Cd, Cu and Pb) and one metalloid (As) in surface sediments of Msimbazi estuary are presented. Surface sediment samples (0–5 cm) were collected from Msimbazi River estuary in September 2016 using handheld PVC short corers. Long-sediment cores from the site were also collected using PVC pipes and their vertical profiles of metals concentrations assessed with the aim of establishing site-specific baseline metals concentrations. The established site-specific baseline values were used for the determination of normalised enrichment factors (EF) and geoaccumulation (Igeo) of metals instead of using average crustal values. Iron-based enrichment factors show that the sediments of Msimbazi have experienced enrichment of metals that originate from anthropogenic sources of pollution (EF > 1). Geo-accumulation results indicate that Msimbazi sediments can be designated as uncontaminated to moderately-contaminated with As, Cd and Pb (class 1–2). Geoaccumulation indices for Cu indicate that sediment can be designated as uncontaminated to moderately contaminated (class 1) and moderately to strongly contaminated (class 3). Results show further that the Ecological Risk associated with the accumulation of these metals in Msimbazi sediments was low based on Hakanson approach.     

Uptake and toxicity of some pesticides on three freshwater fishes (Oreochromis niloticus,Clarias gariepinus and Chrysicthys nigrodigitatus)

Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used by farmers and industrialists were studied in concrete ponds at the University of Cape Coast, in Ghana. The fishes used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus, and were obtained from cultured ponds in the Cape Coast District and Mankessim in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fishes via water. Gas chromatograph (GC) Electron Capture Detector (ECD) analysis was done on the dead fishes to see the extent of ingestion. The LC₅₀ values obtained for lindane on the three fish samples were as follows: Chrysicthys?–?0.38?mg?L^?1; Oreochromis?–?0.42?mg?L^?1, and Clarias?–?1.2?mg?L^?1. Mortalities occurred in fish within 3–5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC₅₀ values were 0.42, 0.32 and 0.64?mg?L^?1, respectively for over a 2–3 day period. For a three-time influx period of propoxur the LC₅₀ for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg?L^?1), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fishes. Gonadosomatic indices also showed that the pesticides affected the development of the body, the gonads, and their reproduction.     

Historical survey and the cultivation of a new culture regarding the ecology in China's Western Provinces

The Chinese leadership in recent years has clearly indicated that priority will be given to the development of the western provinces. In view of its under-developed economy, the relative poor education of the population and the extensive mode of development, environmental pollution and ecological damage in western China are more serious than in the east. In China's industrialization process in the modern era, the blind imitation of the initial stage of industrialization in the advanced countries and the total rejection of traditional Chinese cultural values have been particularly striking. Hence, the western provinces should adopt a mode of sustainable development based on establishment of an ecological culture. Environmentalists in China would like to concentrate on reforming the modes of production and the people's lifestyles through changing their views and values. They perceive this as the major commitment for building an ecological culture and promoting sustainable development. But large-scale and concentrated damage to the environment are very often the result of neglect and mistakes by government authorities and corporations. Pessimists worry that this millennium will signal the terminal stage for natural values; but there may be an alternative: a millennium of coordinated development, respecting the environment and based on adoption of a new ecological culture.     

Values and willingness-to-pay for sustainability-certified mobile phones

ABSTRACT

This study investigated whether endorsement of personal values is associated with willingness to pay more for mobile phones with an environmental or social sustainability label. Participants were students in Sweden, Norway and Germany. A self-report inventory was used to measure willingness to pay and the importance attached to values of Schwartz’s circular model. In Sweden and Norway, participants were willing to pay, on average, 18% extra for a mobile phone with labels for environmental or social sustainability. In Germany, the corresponding share was 12%. To strive for self-enhancement values, that is, social status and prestige, as well as control and dominance over people and resources, was associated with a lower willingness to pay for mobile phones with labels for environmental or social sustainability in all three countries. Furthermore, women were willing to pay more than men for mobile phones with both kinds of sustainability labels. In Sweden and Norway, participants were, on average, willing to pay more for a mobile phone with a label for social sustainability compared to a mobile phone with a label for environmental sustainability.     

Multi-temporal land use and cover changing analysis: the environmental impact in Mediterranean area

ABSTRACT

Human activity shapes the levels of anthropogenic pressure that depend on the land management method adopted. This has a fundamental role in the transformation of traditional landscapes. This study focuses on a representative region of the Mediterranean area with the objective to analyse the landscape’s dynamics, to detect the spatial arrangement of class patches, to identify the main agroecosystem characters and to provide a framework to assess ecosystems services. In order to assess land use/land cover changes and landscape persistence, the period between 1960 and 2012 was analysed, taking into consideration the years 1960, 2000 and 2012 using comparable land use maps. Land use and land cover analysis show an urban area growth of 24% during 2000–2012 and of 523% over between 1960 and 2012. The very high levels of land abandonment up to the year 2000 (+7216%) have reversed their trend between 2000 and 2012 (?95%). The orchards showed a relevant increase, particularly after 2000, while the vineyards were linked to the highest value of surface erosion (?74%). The outcomes showed that urban settlements can damage the ecological network with negative effects on the landscape’s environmental sustainability in proximity of significant urban centres. Instead, the ecological network is well preserved and highly associated to the agricultural areas when there is the persistence of many land uses and low urban density, despite the presence of dynamic changes.     

Financial incentives,professional values and performance: A study of pay‐for‐performance in a professional organization

We investigated the effect of financial incentives on performance in a professional organization. Whereas agency theory treats tangible rewards such as money as a potentially powerful motivator for improving performance, the professional control perspective posits that the motivational effects of financial incentives will depend on the intended recipients attitudes toward the incentives relative to their professional values. The study setting was a large network of physician practices that adopted a financial incentive program to improve physician performance in the management of diabetic patients. Consistent with agency theory, performance did improve following the introduction of the incentive. However, consistent with the professional control perspective, physicians' psychologically based attitudes toward the incentive program regarding its impact on their own work autonomy and the importance of the performance goals moderated the effect of the incentive on performance. Study findings indicate that agency theory and professional control are complementary theoretical perspectives for understanding how professionals will respond to the imposition of performance‐related financial incentives. In terms of practice, pay‐for‐performance programs aimed at professional organizations should be designed to take into account the values and goals of an organization's professionals to maximize the effect of financial incentives on performance. Copyright © 2012 John Wiley & Sons, Ltd.