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211.
212.
Alison Rothwell Brad Ridoutt Girija Page William Bellotti 《Journal of Environmental Planning and Management》2016,59(4):643-665
With urban areas responsible for a significant share of total anthropogenic emissions, greenhouse gas (GHG) emissions due to land-use change (LUC) induced by peri-urban (PU) development have the potential to be considerable. Despite this, there is little research into the transition from PU cropland to housing in terms of contribution to global warming. This paper presents a cross-sectoral integrative method for prospective climate change evaluation of PU LUC. Specifically, direct LUC (dLUC) GHG emissions from converting PU cropland to greenfield housing were examined. Additionally, GHG emissions due to displaced crop production inducing indirect LUC (iLUC) elsewhere were assessed. GHG impacts of dLUC and iLUC were each determined to be approximately 8 per cent of total GHG emissions due to a greenfield housing development displacing PU cropland. This magnitude of dLUC and iLUC emissions suggests that both have importance in future land-use decision making with respect to PU environments. 相似文献
213.
214.
Jiang Gaoming 《环境科学学报(英文版)》1996,8(1):77-85
TreeringanalysisfordeterminationofpollutionhistoryofChengdeCity,northChina¥JiangGaoming(InstituteofBotany,ChineseAcademyofSci... 相似文献
215.
Efficiency and Concordance of Alternative Methods for Minimizing Opportunity Costs in Conservation Planning 总被引:1,自引:0,他引:1
Abstract: Scarce resources and competing land-use goals necessitate efficient biodiversity conservation. Combining multicriteria analysis with conservation decision-support tools improves efficiency of conservation planning by maximizing outcomes for biodiversity while minimizing opportunity costs to society. An opportunity cost is the benefit that could have been received by taking an alternative course of action (i.e., costs to society of protecting an area for biodiversity rather than developing it for some other use). Although different ways of integrating multiple opportunity costs into conservation planning have been suggested, there have been no tests as to which method is most efficient. We compared the relative efficiency of 3 such procedures ( Faith & Walker [1996] , Sarkar et al. [2004] , and a procedure of our own design) in a systematic conservation-planning framework for the Milne Bay Province of Papua New Guinea. We devised 14 opportunity costs and assigned these to 3 scenarios representing different conservation planning concerns: food security, macro-economic development, and biodiversity persistence. For each scenario, we compared the efficiency of the 3 methods in terms of amount of biodiversity protected relative to total expenditure for each opportunity cost. All 3 methods captured similar amounts of biodiversity, but differed in total cost. Our method had the least overall cost and was therefore most efficient. Nevertheless, there was a high correlation and geographical concordance among all 3 methods, indicating a high degree of spatial overlap. This suggests that choosing an appropriate approach may often depend on contextual factors related to the design of the planning question, rather than efficiency alone. 相似文献
216.
Kathryn B. McNamara Mark A. Elgar Therésa M. Jones 《Behavioral ecology and sociobiology》2008,62(9):1433-1440
Species where most but not all females mate monandrously can provide insight into the potential factors both promoting and
restricting polyandry. Polyandry is typically explained by direct and/or indirect benefits models; however, polyandry may
also confer costs via sexually antagonistic processes. The fitness of polyandrous and monandrous females may also vary with
environmental conditions, such as availability of water. For some lepidopterans, water is a vital resource that increases
fecundity and may be a direct benefit of multiple mating. Male lepidopterans transfer large spermatophores that may be an
important water source for females, particularly for species living in water-depauperate environments. In such species, multiple-mating
females may increase their reproductive output. We examined the fitness consequences of multiple mating in the almond moth,
Cadra cautella. Males transfer substantial spermatophores; these have a large chitinous process attached, which decrease female longevity.
To assess the impact of female mating treatment and water availability on female fitness, females mated once or twice, either
with the same or different males, with half the females in each treatment receiving water. Water-fed females had dramatically
increased fecundity, but we found no fitness benefits of multiple mating. Male longevity decreased with increased mating frequency
and potentially his level of reproductive investment. Water-deprived females that mated twice died sooner than once-mated
females, while multiple-mating females that received water lived longer than their water-deprived counterparts. It is interesting
to note that the male’s spermatophore process did not affect female fitness or longevity. Why polyandry is maintained in this
species is discussed. 相似文献
217.
Facultative joint colony founding by social insects provides opportunities to analyze the roles of genetic and ecological
factors in the evolution of cooperation. Although cooperative nesting is observed in range of social insect taxa, the most
detailed studies of this behavior have been conducted with Hymenoptera (ants, bees, and wasps). Here, we show that foundress
associations in the haplodiploid social thrips Dunatothrips aneurae (Insecta: Thysanoptera) are most often comprised of close relatives (sisters), though groups with unrelated foundresses are
also found. Associations among relatives appear to be facilitated by limited female dispersal, which results in viscous population
structure. In addition, we found that per capita productivity declined with increasing group size, sex ratios were female-biased,
and some female offspring apparently remained in their natal domicile for some time following eclosion. D. aneurae thus exhibits a suite of similarities with eusocial Hymenoptera, providing evidence for the convergent evolution of associated
social and life-history traits in Hymenoptera and Thysanoptera. 相似文献
218.
Anders Pape Møller 《Behavioral ecology and sociobiology》2008,63(1):63-75
Numerous species have adapted to humans, especially invasive species associated with humans in towns and cities. Short flight
distances of populations adapted to urban environments reflect changes in behavior and physiology, reflecting phenotypic plasticity
or evolution. Here, I tested the hypothesis that the decrease in flight distance to a potential predator (an approaching human)
reflected adaptation to urbanization, using a data set of flight distances of 44 common species of European birds in different
stages of adaptation to urban environments. Urban populations had consistently shorter flight distances than rural populations
of the same species. Variation in relative flight distance of urban populations was predicted by the number of generations
since urbanization, as expected by a gradual process of adaptation. Furthermore, species with relatively large populations
in urban environments would be an indication of local adaptation to urban environments. Relative flight distance of urban
population was shorter for species with large populations in urban compared to rural habitats. Species that had adapted to
urban environments as shown by short flight distances were less susceptible to predation by the European sparrowhawk Accipiter nisus than species with relatively long flight distances in urban populations. These findings provide evidence consistent with
the hypothesis that recent changes in the tameness of urban birds, as reflected by their relatively short flight distances,
is an adaptation to the novel urban environment.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
219.
Insect larvae increase in size with several orders of magnitude throughout development making them more conspicuous to visually
hunting predators. This change in predation pressure is likely to impose selection on larval anti-predator behaviour and since
the risk of detection is likely to decrease in darkness, the night may offer safer foraging opportunities to large individuals.
However, forsaking day foraging reduces development rate and could be extra costly if prey are subjected to seasonal time
stress. Here we test if size-dependent risk and time constraints on feeding affect the foraging–predation risk trade-off expressed
by the use of the diurnal–nocturnal period. We exposed larvae of one seasonal and one non-seasonal butterfly to different
levels of seasonal time stress and time for diurnal–nocturnal feeding by rearing them in two photoperiods. In both species,
diurnal foraging ceased at large sizes while nocturnal foraging remained constant or increased, thus larvae showed ontogenetic
shifts in behaviour. Short night lengths forced small individuals to take higher risks and forage more during daytime, postponing
the shift to strict night foraging to later on in development. In the non-seasonal species, seasonal time stress had a small
effect on development and the diurnal–nocturnal foraging mode. In contrast, in the seasonal species, time for pupation and
the timing of the foraging shift were strongly affected. We argue that a large part of the observed variation in larval diurnal–nocturnal
activity and resulting growth rates is explained by changes in the cost/benefit ratio of foraging mediated by size-dependent
predation and time stress. 相似文献
220.
Female choice and male–male aggression are two modes of sexual selection that can lead to elaboration of male morphological
and behavioral traits. In lek-mating species, male mating success is often strongly skewed, and it is puzzling why variation
in male traits is still observed given directional female choice. If male traits correlated with reproductive success are
honest signals of male quality, there may be survival costs associated with the expression of those traits. In this study,
we examined whether morphological, behavioral, and territorial traits are correlated with male mating success and survival
in the lek-mating greater prairie-chicken (Tympanuchus cupido). We introduce a novel application of multinomial discrete choice models for analysis of female mate choice behavior. We
found that behavioral and territorial attributes showed 6.5 times more variability among males than morphological traits.
Both display and aggressive behaviors were strong predictors of male mating success, suggesting that both female choice and
male–male aggression were important in determining mating success among male greater prairie-chickens. Moreover, annual survival
of male prairie-chickens was independent of mating success and male traits. Females appear to be choosing males based on behavioral
traits where large variation exists between males (coefficient of variation >30%). Behavioral traits were the most important
factor in determining mating success of male prairie-chickens, but the mechanism underlying this relationship is unknown.
In the future, experimental manipulations of male hormones or parasite loads could bridge the proximate mechanisms and ultimate
consequences of factors mediating male mating success in lek-mating grouse. 相似文献