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121.
Burnout research over the past 30 years has yielded both knowledge and tools to apply to interventions at unit and organizational levels. Examples of innovative partnerships between researchers and practitioners point to the importance of multi‐level approaches in generating relevant and effective solutions to the burnout problem. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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124.
David M Lodge Susan Williams Hugh J MacIsaac Keith R Hayes Brian Leung Sarah Reichard Richard N Mack Peter B Moyle Maggie Smith David A Andow James T Carlton Anthony McMichael 《Ecological applications》2006,16(6):2035-2054
The Ecological Society of America has evaluated current U.S. national policies and practices on biological invasions in light of current scientific knowledge. Invasions by harmful nonnative species are increasing in number and area affected; the damages to ecosystems, economic activity, and human welfare are accumulating. Without improved strategies based on recent scientific advances and increased investments to counter invasions, harm from invasive species is likely to accelerate. Federal leadership, with the cooperation of state and local governments, is required to increase the effectiveness of prevention of invasions, detect and respond quickly to new potentially harmful invasions, control and slow the spread of existing invasions, and provide a national center to ensure that these efforts are coordinated and cost effective. Specifically, the Ecological Society of America recommends that the federal government take the following six actions: (1) Use new information and practices to better manage commercial and other pathways to reduce the transport and release of potentially harmful species; (2) Adopt more quantitative procedures for risk analysis and apply them to every species proposed for importation into the country; (3) Use new cost-effective diagnostic technologies to increase active surveillance and sharing of information about invasive species so that responses to new invasions can be more rapid and effective; (4) Create new legal authority and provide emergency funding to support rapid responses to emerging invasions; (5) Provide funding and incentives for cost-effective programs to slow the spread of existing invasive species in order to protect still uninvaded ecosystems, social and industrial infrastructure, and human welfare; and (6) Establish a National Center for Invasive Species Management (under the existing National Invasive Species Council) to coordinate and lead improvements in federal, state, and international policies on invasive species. Recent scientific and technical advances provide a sound basis for more cost-effective national responses to invasive species. Greater investments in improved technology and management practices would be more than repaid by reduced damages from current and future invasive species. The Ecological Society of America is committed to assist all levels of government and provide scientific advice to improve all aspects of invasive-species management. 相似文献
125.
Charlotte E Gonzalez-Abraham Volker C Radeloff Todd J Hawbaker Roger B Hammer Susan I Stewart Murray K Clayton 《Ecological applications》2007,17(7):2011-2023
Rural America is witnessing widespread housing development, which is to the detriment of the environment. It has been suggested to cluster houses so that their disturbance zones overlap and thus cause less habitat loss than is the case for dispersed development. Clustering houses makes intuitive sense, but few empirical studies have quantified the spatial pattern of houses in real landscapes, assessed changes in their patterns over time, and quantified the resulting habitat loss. We addressed three basic questions: (1) What are the spatial patterns of houses and how do they change over time; (2) How much habitat is lost due to houses, and how is this affected by spatial pattern of houses; and (3) What type of habitat is most affected by housing development. We mapped 27 419 houses from aerial photos for five time periods in 17 townships in northern Wisconsin and calculated the terrestrial land area remaining after buffering each house using 100- and 500-m disturbance zones. The number of houses increased by 353% between 1937 and 1999. Ripley's K test showed that houses were significantly clustered at all time periods and at all scales. Due to the clustering, the rate at which habitat was lost (176% and 55% for 100- and 500-m buffers, respectively) was substantially lower than housing growth rates, and most land area was undisturbed (95% and 61% for 100-m and 500-m buffers, respectively). Houses were strongly clustered within 100 m of lakes. Habitat loss was lowest in wetlands but reached up to 60% in deciduous forests. Our results are encouraging in that clustered development is common in northern Wisconsin, and habitat loss is thus limited. However, the concentration of development along lakeshores causes concern, because these may be critical habitats for many species. Conservation goals can only be met if policies promote clustered development and simultaneously steer development away from sensitive ecosystems. 相似文献
126.
Diversionary displays of paternal stickleback 总被引:1,自引:0,他引:1
Susan A. Foster 《Behavioral ecology and sociobiology》1988,22(5):335-340
Summary In Crystal Lake, British Columbia, male threespine stickleback (Gasterosteus aculeatus) perform a diversionary display that deters cannibalistic conspecifics from entering their territories and destroying their nests or consuming offspring. In this population, the display consists of males swimming directly out of their territories and rooting aggressively in the substratum, mimicking stickleback feeding on nests of others, or digging for nesting materials. The display is elicited solely by conspecifics, and usually by benthic foraging groups of 2–300 individuals. It usually is elicited when groups are approaching the territory directly. Otherwise the male typically joins the group or remains still in his territory until the group leaves. This observation suggests that males are capable of discriminating conditions under which the display is most likely to be successful. The display is absent in a population in Garden Bay Lake, British Columbia, in which benthic foraging groups are absent. In Crystal Lake the males themselves do not risk predation by the groups, and the tendency of males to perform the display does not change with reproductive condition. Comparison with diversionary displays performed in two additional allopatric populations suggests that diversionary displays in this species incorporate elements of other behavioral sequences displaced to the display, and that variation in the structure of the display exists among populations. 相似文献
127.
Inter-specific variation in anti-predator behavior in sympatric species of kangaroo rat 总被引:2,自引:0,他引:2
Jan A. Randall Susan M. Hatch Evon R. Hekkala 《Behavioral ecology and sociobiology》1995,36(4):243-250
Kangaroo rats, Dipodomys, occupy desert habitats with little cover and thus are under high predation risk from diverse predators. The behavior used to assess predation risk or to escape capture is unknown. We therefore compared anti-predator behavior of two sympatric species of kangaroo rat of different sizes, D. merriami and D. spectabilis. We first examined whether kangaroo rats use olfaction as a first line of defense against snake predation and tested the rats for their responses to scent extracted from two species of snake that live sympatrically with the kangaroo rats, the Mojave rattlesnake (Crotalus scutulatus) and the gopher snake (Pitophis melanoleucus). We also tested for species differences in anti-predator behavior through 15-min interactions between the kangaroo rats and free-moving gopher snakes. We found that D. spectabilis actively approached the scent of both rattlesnakes and gopher snakes more than controls of vegetable oil and evaporated solvent (Fig. 1). In contrast, D. merriami did not differentiate snake odors from controls in the experimental arena, but they sniffed the sand where a free-moving snake had passed more than D. spectabilis. Both species successfully avoided predation in encounters with live snakes. Although total numbers of approaches and withdrawals were similar (Fig. 2), D. spectabilis spent significantly more time within striking distance of the snake than D. merriami. D. spectabilis approached the head of the snake in 93% of its approaches and often engaged in nose to snout contact with the snake. If the snake struck, D. spectabilis jumped directly backward to avoid a strike and footdrummed at a safe distance. In contrast, D. merriami oriented to the snake more than D. spectabilis, but approached the head in only 41% of the approaches and rarely engaged in nose-to-snout contact. The snakes struck, hissed and decreased predatory approaches with D. spectabilis but not with D. merriami (Fig. 3). These results show that kangaroo rats can behaviorally influence the risk of being preyed on by snakes. The two species differ, however, in how they react to snakes. The larger D. spectabilis confronts snakes while the smaller D. merriami monitors snakes from a safe distance and avoids them. 相似文献
128.
Public Attitudes and Knowledge about Ecosystem Management on Department of Defense Land in Florida 总被引:3,自引:0,他引:3
New ecosystem management policies at Eglin Air Force Base, Florida, emphasize the need for public education and involvement in the changing focus of natural resource practices. To collect baseline information for ecosystem management, we measured and compared the knowledge, attitudes, and interests of critical Eglin audiences: recreational users and neighboring citizens. Factor analysis of surveys of 700 permitted recreational users and 1000 neighboring citizens revealed four content areas for measuring knowledge and attitudes: (1) native and endangered species, (2) fire ecology, (3) forest resources, and (4) ecosystem management. Overall, both audiences lacked basic ecological knowledge and held neutral to slightly positive attitudes toward the key content areas. Recreational users were significantly more knowledgeable than general citizens about native and endangered species, fire ecology, and forests. However, citizens held significantly more positive attitudes toward native and endangered species conservation and ecosystem management concepts. Eglin's consumptive recreationists (hunters and anglers) held the most negative views. Sociodemographic information from the surveys suggest that the recreational users and neighboring citizens are a stable, educable population that would respond positively to programs aimed at improving knowledge of and attitudes toward ecosystem management goals at Eglin. 相似文献
129.
American robin nestlings compete by jockeying for position 总被引:9,自引:0,他引:9
Susan B. McRae Patrick J. Weatherhead Robert Montgomerie 《Behavioral ecology and sociobiology》1993,33(2):101-106
Summary We investigated whether nestling American robins (Turdus migratorius) were capable of influencing food distribution in their nests by perceiving that certain sectors of the nest received a relatively high proportion of feedings and positioning themselves accordingly. Feeding observations were obtained from videotape recordings taken at different stages of the nestling period. Parents generally arrived at a predictable location on the nest rim and allocated proportionally more food to nestlings in the central position. The degree of nestling movement was significantly positively correlated with variation in the predictability of parental arrival locations on the nest rim. Furthermore, nestlings moved more in broods suffering brood reduction. This suggests that when competition for food is intense and the location of parental arrival is predictable, nestlings respond by jockeying for access to the most favorable (i.e., central) position in the nest. We conclude that jockeying for position by nestlings can influence the pattern of food allocation by parents, and that hungry nestlings can improve their competitive standing against nestmates by moving to positions where parents are more likely to feed them.
Correspondence to: S.B. McRae 相似文献
130.
Algal turfs are the major primary producing component on many coral reefs and this production supports higher levels in the
complex reef trophic web. Rates of metabolism of algal turfs are related positively to water motion, consistent with limitation
by the diffusion of a substance through a boundary layer. Based on engineering mass transfer theory, we hypothesized that
photosynthesis of algal turfs is controlled by rates of mass transfer and responses of photosynthesis to increasing flow speed
should be predicted by engineering correlations. This hypothesis was tested in ten experiments where photosynthesis was estimated
in a flume/respirometer from changes in dissolved oxygen at eight flow speeds between 0.08 and 0.52 m/s. Flow in the flume
and over the reef at Kaneohe Bay, Oahu, Hawaii was estimated using hot-film thermistor and electromagnetic current meters.
Rates of photosynthesis were related positively to flow in all experiments and plots of the log of the average Sherwood number
(Sh
meas) versus log Reynolds number (Re
D) for each experiment are lower than predicted for mass transfer through a turbulent boundary layer. Algal turf-covered plates
are characterized as hydrodynamically transitional to fully rough surfaces and the lower than predicted slopes suggest that
roughness reduces rates of mass transfer. A negative correlation between algal turf biomass and slopes of the log Sh
meas−log Re
D plots suggests that mass transfer to algal turfs is affected significantly by the physical structure of the algal community.
Patterns of photosynthesis based on changes in dissolved oxygen and dissolved inorganic carbon concentrations (DIC) indicate
that the flow speed effect is not the result of increased flux of oxygen from the algal turfs, and combined with the short
response time to flow speed, suggest that DIC may limit rates of photosynthesis. Although there are differences between flow
in the flume and flow over algal turfs on the reef, these results suggest that photosynthesis is controlled, at least in part,
by mass transfer. The chemical engineering approach provides a framework to pose further testable hypotheses about how algal
canopy height, flow oscillation, turbulence, and substratum roughness may modulate rates of metabolism of coral reef algal
turfs. 相似文献