Endemic pollinator response to organic vs. conventional farming and landscape context in the Cape Floristic Region biodiversity hotspot

The effects of organic management and landscape context on two highly endemic and important pollinator taxa (bees and monkey beetles) were studied in the Cape Floristic Region (CFR) biodiversity hotspot, where a quarter of the land is intensively managed mostly for grape production. This functional group was chosen as there is concern worldwide over pollinator decline, particularly in regions of high levels of endemism of both flora and fauna such as the CFR. Species richness and abundance of bees and monkey beetles were sampled and compared between organic and conventional vineyards, with natural vegetation as reference habitat. Species richness of monkey beetles, but not the species richness of bees, benefited from organic compared to conventional vineyard management. Our findings support the hypothesis that the effects of landscape context and management may be taxon dependent. Monkey beetles have been suggested as strong indicators of disturbance. These beetles are among the most important pollinator guilds in the CFR, as they help to sustain the endemic vegetation of this region. Protection of the remaining natural habitat in close proximity to farmland is an imperative conservation strategy in this region.     

湿地自然保护区生态恢复及其绿色开发探析——以七里海湿地国家级自然保护区为例

七里海湿地是我国国家级自然保护区,世界著名三大古海岸之一。近几十年出现了严重的生态危机,本文借鉴众多湿地保护与开发经验,就七里海湿地生态恢复与绿色开发利用提出了一些可行的措施：依据自然保护区的相关法律法规对其进行切实保护与管理,通过恢复河流生态补水、翻耕苇地、禁捕鸟类等生态修复措施恢复其生态功能,进而发展湿地绿色产业、开展项目建设环评等绿色开发活动发挥其重要的生态、经济和社会价值。     

南麂列岛海域生态系统服务及价值评估研究

基于现场调查与公众调查,结合历史资料,利用市场价格法、影子工程法、旅行费用法等对南麂列岛国家级海洋自然保护区海域潮间带湿地和水域生态系统服务类型及其价值进行了评估研究.结果表明,2003年南麂列岛冉然保护区海域8项主要及部分次要生态系统服务总价值为24 258.23万元,其中供给服务、调节服务、文化服务的价值分别占23.79%、38.18%和38.03%,单位面积服务价值为12 772 元/ha.     

Integration of fuzzy reliability analysis and consequence simulation to conduct risk assessment

Losses of containment within the natural gas network, located in most populated areas, could cause environmental damage, injuries, or even death. Accordingly, it is pivotal to adopt proper approaches to assess and mitigate the risk arising from potential losses. Within this context, it is required to exploit solid reliability and consequence analysis techniques. To this end, this paper presents a methodology established on the integration of a Fuzzy Bayesian Network and consequence simulation. The Bayesian Network is more flexible and realistic than classic approaches because it can consider conditional probabilities and prior information. Furthermore, Leaky Noisy-OR Gates are exploited to allow an easier filling of the Conditional Probability Tables. This task is performed through expert elicitation, adopting Intuitionistic Fuzzy Set Theory and Similarity Aggregation Method. Finally, the severity analysis is performed via a software, named Safeti, which provides an accurate evaluation of the consequences. To show the applicability of the framework, a pressure regulator of a Natural Gas Regulating and Metering Station is considered as case study. The proposed approach can assist asset managers in evaluating the risk arising from the operations, and, accordingly, it can guide them in making maintenance-related decisions to assure the safety of the operations.     

Comments on “Development of an empirical equation for the transverse dispersion coefficient in natural streams” by Tae Myoung Jeon,Kyong Oh Baek and Il Won Seo

In a recent paper published in this journal, Jeon et al. ((2007), Environ Fluid Mech 7(4): 317–329) have presented a new empirical equation for the transverse dispersion coefficient in natural streams that was developed based on the hydraulic and geometric parameters using a regression technique. A total of 32 data sets collected in 32 streams was used. Among them, 16 data sets were used for deriving the new equation, and the other 16 were used for verifying the equation. Starting from dimensional analysis the authors found that transverse dispersion coefficient depends on three parameters, such as sinuosity, aspect ratio and a friction term. The robust least square method was applied to estimate regression coefficients resulting in an equation which allows better prediction of transverse dispersion coefficient than previous literature equations. The discussers would like to highlight some points raised in the paper.     

Migratory orientation of juvenile yellow-rumped warblers (Dendroica coronata) following stopover: sources of variation and the importance of geographic origins

Birds migrating along coastlines may be at increased risk if displacement occurs toward open-ocean. Eastern North America experiences prevailing northwesterly winds during autumn, which could compel some migrants to drift eastward. Therefore, migrants at stop-over sites along this route may be a mixture of on- and off-course individuals. We assessed whether orientation behavior of juvenile yellow-rumped warblers (Dendroica coronata) captured at a stop-over site in southern Nova Scotia was related to where they originated from (i.e., likely on/off-course). We hypothesized three scenarios after displacement: 1) continued orientation in the migratory direction selected before displacement, 2) orientation from the new location toward the previous destination, or 3) correction to regain the original pathway. Using stable isotopes, we determined that stop-over migrants originated from nearby areas (and assumed on-course) and as far away as western Hudson Bay, over 1,600 km northwest (and assumed off-course) of the site. We used video-based orientation registration cages to determine an individuals’ migratory orientation. Because numerous factors influence migratory orientation (e.g., fuel reserves, celestial cues), we simultaneously assessed the influence of body condition and cloud cover, in addition to geographic origin, on orientation behavior. Individuals that originated closer to the site tended to orient more southwesterly. Orientation directions became increasingly more west-northwesterly the further away an individual originated from the site (i.e., the more likely it was to have been displaced). The result is most consistent with scenario three: individuals from northwest origins likely respond to easterly displacement by orienting westerly to reestablish their previous migratory route.     

Seasonal ontogenetic colour plasticity in the adult striated shieldbug <Emphasis Type="Italic">Graphosoma lineatum</Emphasis> (Heteroptera) and its effect on detectability

Camouflage and warning colouration are two important forms of protective colouration. We have studied the detectability of two seasonal colourations in the aposematic striated shieldbug, Graphosoma lineatum. The typical colouration of this insect is red and black, which is also the colouration of the reproductive post-hibernation bugs in our study area in south central Sweden. However, the majority of newly eclosed adults in late summer exhibit a ‘pale’ (light brownish, non-red) and black striation, and these bugs appear quite cryptic to the human eye when sitting on the dried stems and umbels of their host plants. In experiments using photographs of prey in the late-summer habitat shown on a computer screen, we compared the time to detection by human subjects of bugs, which had been manipulated to show either of the two typical seasonal colourations. Time to detection was significantly longer for the pale and black than for the red-and-black striation in images with the bug photographed at two different distances. This indicates that the pale pre-hibernation striation may have a cryptic function. In a separate experiment, we tested detectability of striated and non-striated manipulations of bug pre-hibernation colouration against the late-summer background, and found that time to detection was significantly longer for the striated bugs. We discuss potential functional explanations for the seasonal ontogenetic colour plasticity and suggest that the epidermal pale colour in the late summer provides a benefit of increased camouflage.     

The behavioral ecology of cannibalism in cane toads (<Emphasis Type="Italic">Bufo marinus</Emphasis>)

Laboratory studies show that predatory cane toads (Bufo marinus) exhibit specialized toe-luring behavior that attracts smaller conspecifics, but field surveys of toad diet rarely record cannibalism. Our data resolve this paradox, showing that cannibalism is common under specific ecological conditions. In the wet–dry tropics of Australia, desiccation risk constrains recently metamorphosed toads to the edges of the natal pond. Juvenile toads large enough to consume their smaller conspecifics switch to a primarily cannibalistic diet (67% of prey biomass in stomachs of larger toads). Cannibalistic attack was triggered by prey movement, and (perhaps as an adaptive response to this threat) small (edible-sized) toads were virtually immobile at night (when cannibals were active). Smaller metamorphs were consumed more frequently than were larger conspecifics. The switch from insectivory to cannibalism reflects the high dry season densities of small conspecifics (in turn, due to desiccation-imposed constraints to dispersal) and the scarcity of alternative (insect) prey during dry weather. Our study pond (102 m in circumference) supported >400 juvenile toads, which consumed many metamorphs over the course of our study. Toads appear to be low-quality food items for other toads; in laboratory trials, juvenile toads that fed only on conspecifics grew less rapidly than those that ate an equivalent mass of insects. This effect was not due to parotoid gland toxins per se. Thus, cane toads switch to intensive cannibalism only when seasonal precipitation regimes increase encounter rates between large and small toads, while simultaneously reducing the availability of alternative prey.     

Economic resilience to natural and man-made disasters: Multidisciplinary origins and contextual dimensions

Economic resilience is a major way to reduce losses from disasters. Its effectiveness would be further enhanced if it could be precisely defined and measured. This paper distinguishes static economic resilience—efficient allocation of existing resources—from dynamic economic resilience—speeding recovery through repair and reconstruction of the capital stock. Operational definitions are put forth that incorporate this important distinction. The consistency of the definitions is examined in relation to antecedents from several disciplines. The effectiveness of economic resilience is evaluated on the basis of recent empirical studies. In addition, its potential to be enhanced and eroded is analyzed in various contexts.     

Risk transference and related trends: driving forces towards more mega-disasters

Abstract

In recent decades, the global cost of natural disasters has increased substantially. There are several trends in society and nature that suggest this pattern may continue, with more frequent mega-disasters occurring in the future. In particular, risk perception that is at odds with the “reala” risk underlies the process of risk transference which encourages development that increases long-term vulnerability.