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141.
The Oxford Commission on Sustainable Consumption aims to promote debate and action to achieve sustainable consumption. It has met four times since it was established in 1999. Commission members have undertaken a number of projects around the world, working with communities to explore pathways to more sustainable consumption. This paper summarises the Commission’s progress and the messages emerging from its work. Current consumption trends are supported by a number of social trends, including individualisation, the spread of the market ethos, urbanisation, globalisation, and the increasing awareness of risk and uncertainty. However, these trends contain the seeds of their own limitation. In particular, increasing discourse about ethics and social goals may be the key to a shift towards more sustainable consumption. 相似文献
142.
Andrea L. Jaeger Miehls Doran M. Mason Kenneth A. Frank Ann E. Krause Scott D. Peacor William W. Taylor 《Ecological modelling》2009,220(22):3194
Exotic species invasion is widely considered to affect ecosystem structure and function. Yet, few contemporary approaches can assess the effects of exotic species invasion at such an inclusive level. Our research presents one of the first attempts to examine the effects of an exotic species at the ecosystem level in a quantifiable manner. We used ecological network analysis (ENA) and a social network analysis (SNA) method called cohesion analysis to examine the effect of zebra mussel (Dreissena polymorpha) invasion on the Oneida Lake, New York, USA, food web. We used ENA to quantify ecosystem function through an analysis of food web carbon transfer that explicitly incorporated flow over all food web paths (direct and indirect). The cohesion analysis assessed ecosystem structure through an organization of food web members into subgroups of strongly interacting predators and prey. Our analysis detected effects of zebra mussel invasion throughout the entire Oneida Lake food web, including changes in trophic flow efficiency (i.e., carbon flow among trophic levels) and alterations of food web organization (i.e., paths of carbon flow) and ecosystem activity (i.e., total carbon flow). ENA indicated that zebra mussels altered food web function by shunting carbon from pelagic to benthic pathways, increasing dissipative flow loss, and decreasing ecosystem activity. SNA revealed the strength of zebra mussel perturbation as evidenced by a reorganization of food web subgroup structure, with a decrease in importance of pelagic pathways, a concomitant rise of benthic pathways, and a reorganization of interactions between top predator fish. Together, these analyses allowed for a holistic understanding of the effects of zebra mussel invasion on the Oneida Lake food web. 相似文献
143.
Network structure and parasite transmission in a group living lizard,the gidgee skink, <Emphasis Type="Italic">Egernia stokesii</Emphasis> 总被引:1,自引:1,他引:0
Stephanie S. Godfrey C. Michael Bull Richard James Kris Murray 《Behavioral ecology and sociobiology》2009,63(7):1045-1056
Gidgee skinks (Egernia stokesii) form large social aggregations in rocky outcrops across the Flinders Ranges in South Australia. Group members share refuges
(rock crevices), which may promote parasite transmission. We measured connectivity of individuals in networks constructed
from patterns of common crevice use and observed patterns of parasitism by three blood parasites (Hemolivia, Schellackia and Plasmodium) and an ectoparasitic tick (Amblyomma vikirri). Data came from a 1-year mark-recapture study of four populations. Transmission networks were constructed to represent possible
transmission pathways among lizards. Two lizards that used the same refuge within an estimated transmission period were considered
connected in the transmission network. An edge was placed between them, directed towards the individual that occupied the
crevice last. Social networks, a sub-set of same-day only associations, were small and highly fragmented compared with transmission
networks, suggesting that non-synchronous crevice use leads to more transmission opportunities than direct social association.
In transmission networks, lizards infested by ticks were connected to more other tick-infested lizards than uninfected lizards.
Lizards infected by ticks and carrying multiple blood parasite infections were in more connected positions in the network
than lizards without ticks or with one or no blood parasites. Our findings suggest higher levels of network connectivity may
increase the risk of becoming infected or that parasites influence lizard behaviour and consequently their position in the
network.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and
R. James). 相似文献
144.
Ilya R. Fischhoff Jonathan Dushoff Siva R. Sundaresan Justine E. Cordingley 《Behavioral ecology and sociobiology》2009,63(7):1035-1043
Animal groups arise from individuals’ choices about the number, characteristics, and identity of associates. Individuals make
these choices to gain benefits from their associations. As the needs of an individual change with its phenotype, so too we
expect the nature of its associations to vary. In this paper, we investigate how the social priorities of male plains zebra
(Equus burchelli) depend on reproductive state. An adult male is either a bachelor, and lacking mating access, or a stallion defending a harem.
Multiple harems and bachelor males aggregate in larger herds. Herds frequently split and merge, affording males opportunities
to change associates. Over a 4-year period, we sampled the herd associations in a population of 500–700 zebras. To isolate
the effects of reproductive state on male social behavior, we account for potential confounding factors: changes in population
size, grouping tendencies, and sampling intensity. We develop a generally applicable permutation procedure, which allows us
to test the null hypothesis that social behavior is independent of male status. Averaging over all individuals in the population,
we find that a typical bachelor is found in herds containing significantly more adults, bachelors, and stallions than the
herds of a typical stallion. Further, bachelors’ bonds with each other are more persistent over time than those among stallions.
These results suggest that bachelors form cohesive cliques, in which we may expect cooperative behaviors to develop. Stallion–stallion
associations are more diffuse, and less conducive to long-term cooperation.
This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and
R. James). 相似文献
145.
Will Allen Ockie Bosch Margaret Kilvington Don Harley and Ian Brown 《Natural resources forum》2001,25(3):225-233
Adaptive, or 'learning by doing', approaches are often advocated as a means of providing increased understanding within natural resource management. However, a number of organisational and social issues need to be resolved if these approaches are to be used successfully. A case study in the South Island high country of New Zealand is used to review what is needed to support an ongoing community-based monitoring and adaptive management programme. First, the case study is described, paying attention to the social context of the resource management problem. The results of a workshop that explored this problem are then outlined, along with a proposed information flow suggested by participants. Requirements for future steps to resolve these problems (such as information protocols and a multi-stakeholder information system) are discussed. Finally, some broad lessons are drawn from this exercise that could help others developing similar approaches. 相似文献
146.
Jörgen I. Johnsson Karin Kjällman-Eriksson 《Behavioral ecology and sociobiology》2008,62(10):1613-1620
Little is known about how cryptic colouration influences prey search in near-surface aquatic habitats, although such knowledge
is critical for understanding the adaptive value of colour crypsis as well as the perceptive constraints influencing foraging
behaviour in these environments. This study had two main aims: (1) to investigate how background colour matching by prey affects
foraging efficiency by brown trout parr and (2) to investigate how foraging ability on cryptic and conspicuous prey is affected
by fish size at age (reflecting dominance). We addressed these questions by training wild brown trout parr to forage individually
on live brown-coloured maggots on a cryptic (brown) or conspicuous (green) background. A separate experiment confirmed the
absence of trout preference for brown or green substrate. The results show that prey background colour matching increases
search time in brown trout. Search time generally decreased by learning, but conspicuous prey remained an easier prey to find
throughout the six training trials. Thus, perceptive constraints appear to limit search efficiency for cryptic prey, suggesting
that cryptic colouration can confer survival benefits to prey in natural environments. Smaller fish generally found conspicuous
prey faster than larger individuals, whereas search time for cryptic prey was not influenced by body size. This suggests that
smaller individuals compensate for inferior competitive ability by increasing foraging activity rather than improving cognitive
ability. The technique of varying cognitive demands in behavioural tasks could be used more in future studies aimed at distinguishing
motivational effects from cognitive explanations for variation in behavioural performance. 相似文献
147.
In mammalian polygynous mating systems, male reproductive effort consists mainly of male–male competition and courting of
females, which entail substantial somatic costs. Males are thus expected to adjust their reproductive effort according to
their age and condition. In this study, we examined how activity budgets of male mountain goats (Oreamnos americanus), a polygynous ungulate, varied with age in a marked population over two periods: (1) summers 1995–2006 and (2) ruts 2004–2006.
We then assessed if the proportions of time spent in male–male competition and courtship behaviors were influenced by age-specific
body mass and social rank during the rut. Males spent most of their time foraging and resting during summer, and rested more
and foraged less with increasing age. During the rut, pronounced shifts in activity budgets occurred as juveniles (1–2 years)
increased time spent foraging, whereas adults (≥3 years) increased standing and time spent in social interactions at the expense
of foraging. At old age, reproductive effort either stabilized or decreased slightly, providing weak support for the ‘mating
strategy–effort’ hypothesis, predicting that courtship behaviors should peak in prime-aged males. Age-specific body mass did
not affect time spent in male–male competition, but was positively related with time spent in courtship behaviors, providing
support for the ‘individual quality’ hypothesis, predicting that males with more resources at the start of the rut should
spend more time in mating-related activities. Age-specific social rank did not affect reproductive effort. Surviving to prime
age while increasing mass each year should thus allow male ungulates to gain greater ability to court estrus females. 相似文献
148.
Timothy A. Linksvayer 《Behavioral ecology and sociobiology》2008,62(5):647-657
Conflicts of interest among genetically heterogeneous nestmates in social insect colonies have been emphasized as driving
colony resource allocation. However, potential intracolonial conflicts may not actually be realized so that resource allocation
could be shaped primarily by among-colony selection that maximizes colony productivity. To elucidate the causal basis of patterns
of resource allocation, I experimentally manipulated three fundamental aspects of colony social structure (relatedness among
workers, relatedness among larvae, and queen presence) in the ant Temnothorax curvispinosus and measured effects on colony resource allocation to new workers, gynes, and males. The experimental manipulations had widespread
effects on patterns of colony resource allocation, but there was little evidence for realized conflicts over the sex ratio
and caste ratio. Decreasing nestmate relatedness caused decreased colony productivity, suggesting that more closely related
nestmates have more favorably interacting phenotypes. Together, these results suggest that resource allocation in T. curvispinosus may be shaped more by among-colony selection than intracolonial conflict, leading to queen–worker–brood coadaptation. 相似文献
149.
Partha Dasgupta 《Sustainability Science》2007,2(1):5-11
In this lecture, I demonstrate how very different macroeconomic history begins to look if Nature is included as a capital
asset in production activities. The tentative conclusions I draw from the evidence are: (1) high population growth in the
world’s poorest regions (South Asia and sub-Saharan Africa) has been an obstacle to the achievement of sustainable economic
development there; relatedly, (2) when population growth is taken into account, the accumulation of manufactured capital,
knowledge, and human capital (health and education) has not compensated for the degradation of natural capital in South Asia
and sub-Saharan Africa and, in all probability, even in the UK and the US; (3) China is possibly an exception to (1) and (2).
This article is based on the Keynote Lecture delivered at the international symposium on “Sustainability in an Unequal World”,
held in Tokyo on November 24, 2006. The exposition relies on my book, Economics: A Very Short Introduction, Oxford University Press, Oxford, 2007.
The author is the Frank Ramsey Professor of Economics at the University of Cambridge and a Fellow of St. John’s College,
Cambridge. 相似文献
150.
对2017~2019年晋中盆地主要城市PM10和PM2.5逐时浓度资料进行了分析,给出了晋中市和太原市颗粒物浓度主要分布特征;此外利用PM2.5逐时浓度资料,结合HYSPLIT后向轨迹模型,通过轨迹密度分析(TDA)、轨迹停留时间分析(RTA)和潜在源贡献因子分析(PSCF),并对PM2.5逐时浓度资料和对应时刻风向数据进行分析,探讨了晋中盆地主要城市冬季PM2.5传输特征.结果表明,太原市颗粒物浓度整体水平高于晋中市,月、季变化特征类似,均呈现冬季高,夏季低的特征,最高值出现在1月.晋中市受静稳型天气形势引起的颗粒物污染较受沙尘型天气形势导致的颗粒物污染相较太原市更普遍一些;颗粒物的分布呈现出晋中市中间值较多,太原市高值偏多、低值偏少的特点,冬季为晋中盆地PM2.5污染高发季节.晋中盆地主要城市冬季PM2.5传输通道均可分为4类:第一类通道沿太行山横谷传输,第二类通道为偏东南方向传输通道,第一、二类均为近距离传输通道,气团会携带较多... 相似文献