Interagency Resource Teams: a Model for Collaborative Approaches to Environmental Education

Abstract: The Undergraduate Interagency Resource Teams at the White Mountain Research Station of the University of California were created in 1994 to support resource-agency mandates and academic research objectives by providing qualified students who can learn, apply, and improve research and agency monitoring protocols. Drawing from documented elements of other successful internship programs, we identified four basic components that we believe may enhance the potential success of the interns: (1) self-directed learning methodologies, (2) multidisciplinary approaches to science, (3) reflection on and documentation of intern learning, and (4) principles of a positive work environment, including teamwork, conflict resolution, and effective communication. During a 10-week summer session, the Interagency Resource Teams expose approximately 17 students to the professional worlds of natural resource agencies and research scientists. In this environment, we have also observed that the internship program not only exposes students to resource management careers but may also help bridge the gap between resource agency specialists and academic researchers.     

水资源可持续利用的系统动力学仿真研究

如何保护城市环境、合理开发利用自然资源,是当今世界所面临的共同问题。针对我国城市资源与环境的特点,要使经济快速,持续发展,必然解决好水资源的持续利用问题。本文以吉林西部地区乾安县为例,应用系统动力学的原理与方法开展了该区水资源可持续利用系统仿真研究,经过政策模拟对比,提出了符合乾安县经济发展的最佳方案。     

基于目标规划模型的大连市水资源承载力分析

结合“大大连”建设的规划和“十五”及2010年远景规划,选取了人口、国内生产总值、公共绿地面积三个决策变量建立目标规划模型,采取3种方案对大连市水资源承载力进行预测,通过对预测结果的分析并结合水资源承载力的特点提出增强水资源承载力的方案:以可持续发展的观点来设计城市发展规划;调整和改造产业结构;改变城市绿化结构;兴修水利,发展节水技术达到水资源可持续利用。     

Local Participation in Natural Resource Monitoring: a Characterization of Approaches

Abstract: The monitoring of trends in the status of species or habitats is routine in developed countries, where it is funded by the state or large nongovernmental organizations and often involves large numbers of skilled amateur volunteers. Far less monitoring of natural resources takes place in developing countries, where state agencies have small budgets, there are fewer skilled professionals or amateurs, and socioeconomic conditions prevent development of a culture of volunteerism. The resulting lack of knowledge about trends in species and habitats presents a serious challenge for detecting, understanding, and reversing declines in natural resource values. International environmental agreements require signatories undertake systematic monitoring of their natural resources, but no system exists to guide the development and expansion of monitoring schemes. To help develop such a protocol, we suggest a typology of monitoring categories, defined by their degree of local participation, ranging from no local involvement with monitoring undertaken by professional researchers to an entirely local effort with monitoring undertaken by local people. We assessed the strengths and weaknesses of each monitoring category and the potential of each to be sustainable in developed or developing countries. Locally based monitoring is particularly relevant in developing countries, where it can lead to rapid decisions to solve the key threats affecting natural resources, can empower local communities to better manage their resources, and can refine sustainable‐use strategies to improve local livelihoods. Nevertheless, we recognize that the accuracy and precision of the monitoring undertaken by local communities in different situations needs further study and field protocols need to be further developed to get the best from the unrealized potential of this approach. A challenge to conservation biologists is to identify and establish the monitoring system most relevant to a particular situation and to develop methods to integrate outputs from across the spectrum of monitoring schemes to produce wider indices of natural resources that capture the strengths of each.     

Resource translocation in a marine bryozoan: quantification and visualization of 14C and 35S

Colonial marine invertebrates are characterized by their ability to share resources among the modules of a colony. In most colonial groups, but particularly the Bryozoa, the dynamics of resource transport among modules is unknown. We developed radioisotope techniques to visualize and quantify the movement of carbon and sulfur-based compounds within colonies of the marine bryozoan Membranipora membranacea. The research was conducted in 1991 and 1992 in Friday Harbor, Washington, USA. Autoradiography, using X-ray film, was used to visualize the transport of both ¹⁴C and ³⁵S, and a liquid scintillation counter was used to quantify transport of metabolites. We were able to localize feeding by introducing 10 l aliquots of labelled algal cells with a microinjection syringe into a containment ring on the surface of the colony. The labelled cells were consumed by zooids feeding within the ring, but not by those outside. In time-course within the ring, but not by those outside. In time-course experiments, 15% of the ingested carbon radioisotope was transported from a source in the center of the colonies to the growing edges over a period of 48 h. Approximately 10% of the sulfur was transported from central to edge regions of colonies over 72 h. Transport of carbon isotope was unidirectional in all experiments, irrespective of whether colonies were fed near the edge or the center. Pulse-chase experiments revealed that up to 46% of the initial ¹⁴C radioisotope was lost from the colony to respiration and egestion in the 24 h following ingestion.     

Pollution Permits and Sustainable Growth in a Schumpeterian Model

In Chapter 4 of their book (“Endogenous Growth Theory,” MIT Press, Cambridge, MA (1998)), Aghion and Howitt introduce environmental pollution in an aggregate Schumpeterian model and characterize the optimal path. In this paper, we study the equilibria in a decentralized economy compatible with their model. First, we study the trade-off between environmental quality and growth and identify the channels of transmission of environmental policy into growth performance. Then, we compute the levels of the tools which are used to implement the optimum.     

Resource degradation: a subtle effect of bottom fishing

Populations of hermit crabs are critically limited by the availability of suitable gastropod shells that they utilise to reduce their risk of predation and environmental stress. Common whelks are the main source of shells for large hermit crabs in the northern Atlantic but are vulnerable to direct and indirect effects of fishing activity. This study examined the potential consequences of degrading shell resources for common hermit crabs. Laboratory trials demonstrated that hermit crabs avoid low-quality damaged shells throughout their life history. This laboratory preference was corroborated by direct field observations of shells preferentially occupied by hermit crabs, compared with shells available for occupation. In the field, 8 times as many empty shells had holes compared to shells occupied by hermit crabs. In the North Sea, the abundance and biomass of live whelks and hermit crabs collected at sites where they co-occurred were significantly related. However, whelks occurred at far fewer sites overall and were more patchily distributed at high abundance than hermit crabs, which were more widespread. At a subset of sites, whelks of the same body-mass range occurred in the Irish and North Sea. However, at these sites, hermit crabs sampled from the North Sea had a significantly lower biomass. This suggests that the shells available for occupation at the North Sea sites would not support crabs of a body mass comparable to that found in the Irish Sea. Using published data, we calculated that in some of the intensively fished areas of the North Sea, 24% of the available shell resource will be damaged each year. The reduction in shell quality in the North Sea may impose a physical constraint on the upper size limit currently attainable by hermit crabs and hence may have implications for population viability.Communicated by J. P. Thorpe, Port Erin     

中国的太阳能资源及应用潜力

太阳能资源被认为是21世纪最引人注目的可再生能源和洁净能源，为了经济的可持续发展，应该把环境保护和长期利益作为研究目标，文章估算了中国14个城市的太阳能资源，分析了太阳能热水系统和PIVP系统的经济性，研究结果表明，中国的太阳能利用潜力很大，政府应该对其发展发挥重要作用。     

Resource Depletion and Sustainability in Small Open Economies

Exogenous price changes affect the amount that a small country exporting natural resource commodities must invest to sustain its consumption level. The necessary amount is given by the difference between Hotelling rent and the discounted sum of future terms-of-trade effects (capital gains). The latter term is found to be large relative to the former in the case of petroleum depletion in Indonesia. This suggests that resource-rich countries will need to invest more than previously expected to sustain their consumption levels, if natural resource prices continue their long-term historical decline.     

机体细胞镉摄入离子转运通道研究进展

镉是人体非必需金属离子,长期镉暴露易引发镉中毒。机体内没有负责镉转运的特定载体,镉可通过必需金属离子转运载体进入机体细胞。机体内能够转运镉的载体有多种,主要包括铁的转运载体二价金属离子转运蛋白1(DMT1)、钙离子通道(电压门控钙通道(VGCC)、瞬时感受器电位(TRP)和钙库调控的钙通道(SOC))以及锌铁调控蛋白ZIP家族中的ZIP8和ZIP14等,且不同的机体细胞镉吸收所需转运载体不同。转运载体对镉离子的转运符合米氏方程,不同载体调节镉吸收的米氏常数Km值不同。机体细胞镉的吸收是个复杂的过程,通常存在着多种转运载体的交互作用,机体细胞可根据环境变化而选择镉的转运载体。对镉的生理毒性,以及细胞镉吸收常用的转运载体类型加以阐述,并分析了不同机体细胞镉吸收的可能转运载体,以期为后续探究机体细胞镉吸收具体分子机制提供理论指导。     

Resource selection plasticity and community responses to experimental reduction of a critical resource

Resource selection plasticity and behavioral dominance may influence the ability of a species to respond to changes in resource availability, particularly if dominant species have highly specialized resource requirements. We examined the response of several dominant and subordinate cavity-nesting species to a reduction in the availability of an essential resource (nesting cavities) using the novel experimental approach of blocking the entrances to high-quality cavities. We monitored nest abundance on seven treatment and 13 control sites (aspen groves in a grassland matrix) in British Columbia, Canada, for two years pretreatment (2000-2001), two years during treatment (2002-2003), and two years posttreatment (cavities reopened; 2004-2005). At the community level, nest abundance declined by 50% on treatment sites following cavity blocking and returned to pretreatment levels following cavity reopening. Nest abundance of European Starlings (Sturnus vulgaris), a dominant secondary cavity-nester (SCN), declined by 89% and failed to recover posttreatment. Conversely, nest abundance of Mountain Bluebirds (Sialia currucoides; a subordinate SCN) increased following cavity blocking and remained high following reopening. Tree Swallows (Tachycineta bicolor) were unaffected by cavity blocking. We suggest that starlings, while being the dominant SCN, may be limited by availability of suitable nest sites, whereas bluebirds may be limited by starling abundance. We propose that plasticity in nest site preferences of subordinate cavity-nesters may enable them to contend with natural variation in availability of critical resources, such as nest cavities and food, in addition to coping with interspecific competition. This is the first community-level, multiyear study involving manipulation of nest site availability via experimental cavity blocking.     

Manipulation of Olfactory Signaling and Mate Choice for Conservation Breeding: a Case Study of Harvest Mice

Abstract:  Mate choice by females can introduce difficulties to captive breeding programs because there may be a conflict between the conservation manager's choice of mate (based on random allocation or maximizing heterogeneity) and the females' own preferences, often resulting in incompatibility and aggression. Similar effects are caused by inappropriate social contexts at the time of pairing. We manipulated the social experience of male and female harvest mice ( Micromys minutus ) to investigate whether we could enhance compatibility between randomly allocated mates by altering female preferences. In one experiment, we used a choice test to identify female preferences between two males and then varied the competitive context of unpreferred males by transferring competitor's scent marks into their cages. The manipulation caused them to increase their investment in a form of olfactory signaling (scent marking), which female rodents use as an indicator of male quality when choosing mates. The manipulation increased their attractiveness relative to the initially preferred male when the choice test was repeated. In a second experiment, we tested the effect of females' familiarity with the odor of males by transfer of male scent marks to female cages. Females preferred familiar males in choice tests and were less aggressive toward them when pairs were introduced than females paired with unfamiliar males. This kind of approach can influence mate choice, and transferring scent marks between cages or collections is an effective and practical behavioral means of improving success in conservation breeding programs.     

Resource distributions among habitats determine solitary bee offspring production in a mosaic landscape.

Within mosaic landscapes, many organisms depend on attributes of the environment that operate over scales ranging from a single habitat patch to the entire landscape. One such attribute is resource distribution. Organisms' reliance on resources from within a local patch vs. those found among habitats throughout the landscape will depend on local habitat quality, patch quality, and landscape composition. The ability of individuals to move among complementary habitat types to obtain various resources may be a critical mechanism underlying the dynamics of animal populations and ultimately the level of biodiversity at different spatial scales. We examined the effects that local habitat type and landscape composition had on offspring production and survival of the solitary bee Osmia lignaria in an agri-natural landscape in California (U.S.A.). Female bees were placed on farms that did not use pesticides (organic farms), on farms that did use pesticides (conventional farms), or in seminatural riparian habitats. We identified pollens collected by bees nesting in different habitat types and matched these to pollens of flowering plants from throughout the landscape. These data enabled us to determine the importance of different plant species and habitat types in providing food for offspring, and how this importance changed with landscape and local nesting-site characteristics. We found that increasing isolation from natural habitat significantly decreased offspring production and survival for bees nesting at conventional farms, had weaker effects on bees in patches of seminatural habitat, and had little impact on those at organic farm sites. Pollen sampled from nests showed that females nesting in both farm and seminatural habitats relied on pollen from principally native plant species growing in seminatural habitat. Thus connectivity among habitats was critical for offspring production. Females nesting on organic farms were buffered to isolation effects by switching to floral resources growing at the farm site when seminatural areas were too distant. Overall local habitat conditions (farm management practices) can help bolster pollinators, but maintaining functional connectivity among habitats will likely be critical for persistence of pollinator populations as natural habitats are increasingly fragmented by human activities.     

Resource supplements cause a change in colony sex-ratio specialization in the mound-building ant, Formica exsecta

We examine the role of food resources on split sex ratios in Formica exsecta. Models of resource-based sex allocation predict that greater resources will cause an increase in the production of reproductive females (gynes) and an increase in overall size of offspring. We experimentally increased food resources for a subset of colonies in a polygynous population with a very male-biased sex ratio. This increase in food availability caused colonies that were male specialists the prior year to switch to female production. Overall, a significantly greater proportion of food-supplemented colonies produced gynes, compared to control colonies. Moreover, food-supplemented colonies produced significantly larger workers and males (but not gynes), compared to those produced by control colonies. There was, however, no significant difference in the numerical productivity of food-supplemented and control colonies. We also measured the natural association between colony sex specialization and proximity to conifers, which typically harbor honeydew-bearing aphids (an important natural food source). In line with the view that resources play an important role for determining sex ratios in social insects, we found that female-producing colonies were significantly closer to conifers than were male-producing colonies.     

改善当前我国环境资源管理体制探析

结合当前我国环境资源管理体制的实际,在系统分析其存在问题和弊端的基础上,探讨了问题和弊端产生的具体成因,同时提出了富有建设性的建议。     

甘肃河西走廊城市化与水资源的协调发展

在分析城市化与水资源交互胁迫关系的基础上,借助于系统科学理论建立了城市化与水资源协调发展的动态耦合模型,对甘肃河西走廊城市化与水资源协调发展的动态耦合规律进行了初步探讨。结果表明：自1985年以来,河西走廊城市化水平在曲折发展中呈现出明显升高的变化趋势;水资源压力不断增大,并呈现出对城市化具有一定影响的特征。目前河西走廊正处于城市化与水资源的协调发展阶段,然而随着城市化的推进,水资源压力不断增长,二者的耦合状态有不断减弱的趋势。这也进一步说明,在干旱区,水资源压力随城市化的推进呈现出一定的变化规律,城市化的发展往往是需要一定的水资源压力为代价的,然而随着城市化的发展,城市化与水资源的关系不断得以磨合,最终将朝着协调共生的方向发展。     

Resource extraction and recycling with environmental costs

Extraction and use of a natural resource is assumed to affect the environment adversely. A perfect substitute for the resource can be supplied through a recycling process. Recycling may also have harmful effects on the environment, but to a smaller extent than extraction. The optimal path of extraction and recycling is studied under various assumptions about the environmental effects of recycling and the assimilative capacity of the environment. In particular, it is shown how the cost of recycling will affect initial resource extraction as well as the environmental quality at the time of resource exhaustion and in the long-run stationary state.