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71.
David Blodgett Emily Read Jessica Lucido Tad Slawecki Dwane Young 《Journal of the American Water Resources Association》2016,52(4):845-858
Improving access to data and fostering open exchange of water information is foundational to solving water resources issues. In this vein, the Department of the Interior's Assistant Secretary for Water and Science put forward the charge to undertake an Open Water Data Initiative (OWDI) that would prioritize and accelerate work toward better water data infrastructure. The goal of the OWDI is to build out the Open Water Web (OWW). We therefore considered the OWW in terms of four conceptual functions: water data cataloging, water data as a service, enriching water data, and community for water data. To describe the current state of the OWW and identify areas needing improvement, we conducted an analysis of existing systems using a standard model for describing distributed systems and their business requirements. Our analysis considered three OWDI‐focused use cases—flooding, drought, and contaminant transport—and then examined the landscape of other existing applications that support the Open Water Web. The analysis, which includes a discussion of observed successful practices of cataloging, serving, enriching, and building community around water resources data, demonstrates that we have made significant progress toward the needed infrastructure, although challenges remain. The further development of the OWW can be greatly informed by the interpretation and findings of our analysis. 相似文献
72.
73.
The Galápagos Islands are globally renowned for their ecological value and as a world symbol of scientific discovery; however the native biodiversity of this unique region is currently under threat. One of the primary concerns is the detrimental impact of approximately 750 nonnative plants introduced over the last 500 years of human presence in the archipelago. In addition to these known introduced species, there are an additional 62 vascular plants classified as "doubtful natives," where native status remains unclear. To help address the questions of provenance regarding these doubtfully native species and their impact on highland ecosystems over the past 500-1000 years, we analyzed plant macrofossils in sedimentary records. Appropriate species classification (native or introduced) was determined using baseline data of species presence on the islands. We confirmed that six plants (Ageratum conyzoides, Solanum americanum, Ranunculus flagelliformis, Brickellia diffusa, Galium canescens, and Anthephora hermaphrodita) once considered doubtful natives or introduced are actually native to the Galápagos flora. These results have relevance not just for the Galápagos but also many other oceanic islands in demonstrating the application of palaeobotanical data to conserving and restoring native biodiversity. 相似文献
74.
In order for research into the consequences of biodiversity changes to be more applicable to real-world ecosystems, experiments must be conducted in the field, where a variety of factors other than diversity can affect the rates of key biogeochemical and physiological processes. Here, we experimentally evaluate the effects of two factors known to affect the diversity and composition of intertidal seaweed assemblages--tidal elevation and herbivory--on nitrate uptake by those assemblages. Based on surveys of community composition at the end of a 1.5-year press experiment, we found that both tide height and herbivores affected seaweed community structure. Not surprisingly, seaweed species richness was greater at lower tidal elevations. Herbivores did not affect richness, but they altered the types of species that were present; seaweed species characterized by higher rates of nitrate uptake were more abundant in herbivore-removal plots. Both tide height and herbivores affected nitrate uptake by seaweed assemblages. Individual seaweed species, as well as entire seaweed assemblages, living higher on the shore had greater rates of biomass-specific nitrate uptake, particularly at high ambient nitrate concentrations. Grazed seaweed assemblages exhibited reduced nitrate uptake, but only at low nitrate concentrations. We evaluated the effect of seaweed richness on nitrate uptake, both alone and after accounting for effects of tidal elevation and herbivores. When only richness was considered, we found no effect on uptake. However, when simultaneous effects of richness, tide height, and herbivores on uptake were evaluated, we found that all three had relatively large and comparable effects on nitrate uptake coefficients and that there was a negative relationship between seaweed richness and nitrate uptake. Particularly because effects of richness on uptake were not apparent unless the effects of tide height and herbivory were also considered, these results highlight the importance of considering the effects of environmental context when evaluating the consequences of biodiversity change in more realistic systems. 相似文献
75.
In the absence of predators, pollinators can often maximize their foraging success by visiting the most rewarding flowers.
However, if predators use those highly rewarding flowers to locate their prey, pollinators may benefit from changing their
foraging preferences to accept less rewarding flowers. Previous studies have shown that some predators, such as crab spiders,
indeed hunt preferentially on the most pollinator-attractive flowers. In order to determine whether predation risk can alter
pollinator preferences, we conducted laboratory experiments on the foraging behavior of bumble bees (Bombus impatiens) when predation risk was associated with a particular reward level (measured here as sugar concentration). Bees foraged in
arenas containing a choice of a high-reward and a low-reward artificial flower. On a bee’s first foraging trip, it was either
lightly squeezed with forceps, to simulate a crab spider attack, or was allowed to forage safely. The foragers’ subsequent
visits were recorded for between 1 and 4 h without any further simulated attacks. Compared to bees that foraged safely, bees
that experienced a simulated attack on a low-reward artificial flower had reduced foraging activity. However, bees attacked
on a high-reward artificial flower were more likely to visit low-reward artificial flowers on subsequent foraging trips. Forager
body size, which is thought to affect vulnerability to capture by predators, did not have an effect on response to an attack.
Predation risk can thus alter pollinator foraging behavior in ways that influence the number and reward level of flowers that
are visited. 相似文献
76.
Socialization of young is an important component of maternal care in social mammals. It is therefore perplexing that female
chimpanzees with dependent offspring spend more time alone than females without dependent offspring, and than males. We propose
that chimpanzee mothers are less gregarious than nonmothers and males to reduce the risk of injury that aggressive males pose
to their offspring. We predict that mothers will associate less with males, associate with fewer males, and reduce mother−infant
proximity in the presence of males, and that these effects will reduce with increasing offspring age. We test whether the
pattern of gregariousness and mother−offspring proximity support these predictions in the Kanyawara chimpanzee community in
Uganda. The probability that a female was found in the presence of males was lower for mothers than nonmothers and increased
with offspring age. The probability that a female was found with other females did not differ between mothers and nonmothers.
Mother-to-offspring distance was higher when a mother was in an all-female group than in a mixed-sex group and increased with
her offspring's age. Mother-to-offspring distance was greatest when there were relatively low numbers of males and relatively
high numbers of females in a subgroup. We propose that mothers avoid grouping with males because of the vulnerability of their
young, and that the presence of males in a subgroup increases a female's protectiveness of her young. We discuss the implications
of our findings and the relevance of fission−fusion group formation to chimpanzee mothers. 相似文献
77.
Emily Boyd Nate Hultman J. Timmons Roberts Esteve Corbera John Cole Alex Bozmoski Johannes Ebeling Robert Tippman Philip Mann Katrina Brown Diana M. Liverman 《Environmental Science & Policy》2009,12(7):820-831
The Clean Development Mechanism (CDM) has successfully demonstrated that market-based mechanisms can achieve some cost effective emissions reductions in developing countries. However the distribution of CDM projects has been extremely uneven across countries and regions, and a few technologies and sectors have dominated the early stages of CDM experience. This has caused some to question whether the CDM has fallen short of its potential in contributing to sustainable development. We review the broad patterns of CDM project approvals and evaluate 10 CDM projects according to their sustainability benefits. The difficulty of defining “sustainable development” and the process of defining criteria by individual non-Annex 1 governments has meant that sustainable development concerns have been marginalized in some countries. Given these observed limitations, we present possible CDM policy futures, focusing on the main proposals for a post-2012 climate regime. Five options for enhancing the sustainable development benefits in the CDM are discussed, including proactive approaches to favour eligibility of emission reduction projects which ensure such co-benefits. 相似文献
78.
When three per cent may not be three per cent; device-equipped seabirds experience variable flight constraints 总被引:1,自引:1,他引:0
Current guidelines for instrumenting birds state that external devices should not exceed 3–5% of the birds’ body mass; however,
the energetic consequences of carrying any given device mass are likely to vary according to the morphology and ecology of
the species concerned. We used a freeware program to estimate the mechanical power requirements of flight at the minimum power
speed for 80 species of flying seabird from 8 major groups with payloads of increasing mass. Devices representing 3% of the
bird’s body mass resulted in an increase in energy expenditure for flight ranging from 4.67 to 5.71% without accounting for
the increase in body drag coefficient associated with external devices. This effect differed within and between seabird lineages
with members of the Alcidae and Phalacrocoracidae experiencing the highest energetic costs of any increase in device mass.
We propose that device effects on seabirds could be further reduced through consideration of species-specific effects of added
payload and drag. 相似文献
79.
Both birds and bats are important insect predators in tropical systems. However, the relative influence of birds and bats on insect populations and their indirect effects on leaf damage have not previously been investigated in tropical forest restoration sites. Leaf damage by herbivorous insects can negatively affect the growth and survival of tropical plants and thus can influence the success of tropical forest restoration efforts. We used an exclosure experiment to examine the top-down effects of birds and bats on insects and leaf damage in a large-scale forest restoration experiment. Given the potential influence of tree planting design on bird and bat abundances, we also investigated planting design effects on bird and bat insectivory and leaf damage. The experiment included two planting treatment plots: islands, where trees were planted in patches, and plantations, where trees were planted in rows to create continuous cover. In both types of plots, insect biomass was highest on tree branches where both birds and bats were excluded from foraging and lowest on branches without exclosures where both birds and bats were present. In the island plots, birds and bats had approximately equal impacts on insect populations, while in plantations bats appeared to have a slightly stronger effect on insects than did birds. In plantations, the levels of leaf damage were higher on branches where birds and bats were excluded than on branches where both had access. In island plots, no significant differences in leaf damage were found between exclosure treatments although potential patterns were in the same direction as in the plantations. Our results suggest that both birds and bats play important roles as top predators in restoration systems by reducing herbivorous insects and their damage to planted trees. Tropical restoration projects should include efforts to attract and provide suitable habitat for birds and bats, given their demonstrated ecological importance. 相似文献
80.
Alexander D. M. Wilson Emily M. Whattam Rachel Bennett Laksanavadee Visanuvimol Chris Lauzon Susan M. Bertram 《Behavioral ecology and sociobiology》2010,64(5):703-715
Recently, there has been increasing interest in behavioral syndrome research across a range of taxa. Behavioral syndromes
are suites of correlated behaviors that are expressed either within a given behavioral context (e.g., mating) or between different
contexts (e.g., foraging and mating). Syndrome research holds profound implications for animal behavior as it promotes a holistic
view in which seemingly autonomous behaviors may not evolve independently, but as a “suite” or “package.” We tested whether
laboratory-reared male and female European house crickets, Acheta domesticus, exhibited behavioral syndromes by quantifying individual differences in activity, exploration, mate attraction, aggressiveness,
and antipredator behavior. To our knowledge, our study is the first to consider such a breadth of behavioral traits in one
organism using the syndrome framework. We found positive correlations across mating, exploratory, and antipredatory contexts,
but not aggression and general activity. These behavioral differences were not correlated with body size or condition, although
age explained some of the variation in motivation to mate. We suggest that these across-context correlations represent a boldness
syndrome as individual risk-taking and exploration was central to across-context mating and antipredation correlations in
both sexes. 相似文献