Control of Tamarix in the Western United States: Implications for Water Salvage, Wildlife Use, and Riparian Restoration

Non-native shrub species in the genus Tamarix (saltcedar, tamarisk) have colonized hundreds of thousands of hectares of floodplains, reservoir margins, and other wetlands in western North America. Many resource managers seek to reduce saltcedar abundance and control its spread to increase the flow of water in streams that might otherwise be lost to evapotranspiration, to restore native riparian (streamside) vegetation, and to improve wildlife habitat. However, increased water yield might not always occur and has been substantially lower than expected in water salvage experiments, the potential for successful revegetation is variable, and not all wildlife taxa clearly prefer native plant habitats over saltcedar. As a result, there is considerable debate surrounding saltcedar control efforts. We review the literature on saltcedar control, water use, wildlife use, and riparian restoration to provide resource managers, researchers, and policy-makers with a balanced summary of the state of the science. To best ensure that the desired outcomes of removal programs are met, scientists and resource managers should use existing information and methodologies to carefully select and prioritize sites for removal, apply the most appropriate and cost-effective control methods, and then rigorously monitor control efficacy, revegetation success, water yield changes, and wildlife use.     

Access rights for outdoor recreation in New Zealand: some lessons for open country in England and Wales

Access opportunities for outdoor recreation in New Zealand and England and Wales are classified according to their conformity with collective, citizenship or exclusion rights and their degrees of permanence. Alternative criteria for the apportionment of access rights are considered in the context of this classification. Different criteria for rights apportionment are found to be appropriate according to different circumstances in the context of pluralist provision. Policy developments in New Zealand are compared with those in England. After 150 years of a dominance of collective rights in New Zealand current policy is shifting provision towards exclusionary rights. In England, there is a policy shift in the other direction, towards collective rights. Lessons for the development of collective rights in England are drawn from the New Zealand experience in relation to styles of governance, public preferences, public cost, insurance liability and the potential of markets.     

Construing of self and others at work in the early years of corporate careers

Research has examined personal change and stability in early adulthood but generally with standardized scales and without inviting explicit comparison of self with other people. The present work uses the repertory grid method to examine how graduates construe themselves and others during early career. Ninety-four graduate entrants to a multinational corporation with zero to four years' tenure completed repertory grids on two occasions one year apart. Results shed much light on the graduates' concepts of self relative to others in their work setting, and how these change over time. The graduates generally had fairly positive self concepts, though these did not become more positive with tenure. Most saw themselves much as they thought others saw them. Change in concepts of self varied greatly between graduates, as did the constructs on which those concepts were described. The results cast further doubt on whether organizational socialization affects people in uniform ways.     

Ecological perspective on water quality goals

The central assumption of nonpoint source pollution control efforts in agricultural watersheds is that traditional erosion control programs are sufficient to insure high quality water resources. We outline the inadequacies of that assumption, especially as they relate to the goal of attaining ecological integrity. The declining biotic integrity of our water resources over the past two decades is not exclusively due to water quality (physical/chemical) degradation. Improvement in many aspects of the quality of our water resources must be approached with a much broader perspective than improvement of physical/chemical conditions. Other deficiencies in nonpoint pollution control programs are discussed and a new approach to the problem is outlined.     

Correspondence between spatial patterns in fish assemblages in ohio streams and aquatic ecoregions

Land classification systems can be useful for assessing aquatic ecosystems if relationships among them exist. Because the character of an aquatic ecosystem depends to a large extent upon the character of the landscape it drains, spatial patterns in aquatic ecosystems should correspond to patterns in the landscape. To test this hypothesis, the US state of Ohio was divided into four aquatic ecoregions based on an analysis of spatial patterns in the combination of land-surface form, land use, potential natural vegetation, and soil parent material. During the period July–October 1983, fish assemblages were sampled in 46 streams that were representative of the ecoregions, and that had watersheds relatively undisturbed by human activities. Spatial patterns of the fish assemblages were examined relative to the ecoregions; distinct regional differences were identified. The assemblages differed most between the Huron/Erie Lake Plain region and the Western Allegheny Plateau region; assemblages in the Eastern Corn Belt Plains and the Erie/Ontario Lake Plain-Interior Plateau regions were intermediate. This pattern also reflects the gradient in landscape character as one moves from the northwest to the southeast of Ohio.     

Self-reported driving under the influence of alcohol and cannabis among Ontario students: Associations with graduated licensing,risk taking,and substance abuse

Objective: This article describes the patterns of self-reported driving under the influence of alcohol (DUIA) and driving under the influence of cannabis (DUIC) among licensed Ontario students in 2009 and examines their associations with graduated licensing, risk taking, and substance use problems for understanding DUIA and DUIC behaviors. Ontario's graduated licensing system requires new drivers to hold a G1 license for a minimum of 8 months and a G2 license for a minimum of 12 months before a full and unrestricted G license can be obtained. Among other restrictions, G1 drivers must maintain a 0 blood alcohol content (BAC), have an experienced driver in the passenger seat, not drive on any high-speed expressways, and not drive between the hours of midnight and 5 a.m. A G2 license is more similar to a G license, with fewer restrictions.

Method: This study analyzed data from the 2009 Ontario Student Drug Use and Health Survey (OSDUHS). The OSDUHS is a biennial population-based survey of students (grades 7 to 12) in Ontario, Canada.

Results: The results showed that 16.3% of licensed students in Ontario reported DUIC and 11.5% reported DUIA during the past year. After controlling for the effect of age, type of license emerged as a robust predictor for both DUIA and DUIC behavior, because students with a G2 and full license were significantly more likely to report DUIA and DUIC than drivers with a G1 license. Multivariate analyses suggested that risk-seeking behaviors were more important for understanding DUIA behavior than for DUIC behavior. Elevated problem indicators for alcohol and for cannabis were associated with DUIA and DUIC, respectively.

Conclusions: Though much attention has been paid to drinking and driving among adolescents, this research shows that more Ontario students now report driving after cannabis use than after drinking alcohol. The results identify important correlates of both behaviors that may be useful for prevention purposes.     

Individual and collective choice: parallel prospecting and mining in ants

Decision making is of crucial importance in the lives of both animals and humans. How decisions of group members scale up to group decisions is of great interest. Accordingly, we gave homeless ant colonies (n = 67) in three experiments a choice between two nest sites (with small, big or mixed sand grains), each of which had to be excavated to be habitable. Among the colonies that chose only one of the new nest sites, all preferred the ones that could be excavated most easily and quickly. There are interesting parallels between the collective choice of mining sites and the ability of certain ants to select short cuts; both involve positive feedback. However, in this paper, we discuss a mechanism whereby collective co-ordination in the production of social infrastructure can occur in the absence of signalling.