Social and environmental trade-offs in tree species selection: a methodology for identifying niche incompatibilities in agroforestry

Natural resource degradation in highland regions is of increasing concern to the global community due to its role in aggravating poverty and the loss of environmental services to local and downstream users. The integration of trees into smallholder farming systems has been promoted as a means to enhance rural livelihoods while reversing the degradation of soil, water, biodiversity and related environmental services. Yet in addition to these benefits, negative impacts of trees on certain stakeholders or system components have also accompanied such efforts—suggesting that important trade-offs accompany afforestation. This paper presents a methodology for diagnosing problems stemming from cultivation of certain tree species in specific landscape niches. Data derived from the application of this methodology in two sites in the eastern African highlands are presented. Participatory diagnoses of landscape-level problems suggest that the negative impact of trees on water resource availability and crop yield are of critical concern to smallholder farmers. Ethnoecological data highlight the properties of different tree species that determine their suitability to specific farm and landscape niches. These data point to important opportunities for more socially- and environmentally-optimal integration of indigenous and exotic tree species into agricultural landscapes, and highlight the critical importance of local knowledge in forging solutions appropriate to contemporary realities.     

Prerequisite conditions for meaningful participation in brownfields redevelopment

Current research in environmental planning supports decision making based on collaborative planning mechanisms. While current research clearly details the limitations to and prerequisites for meaningful public participation in general and for select environmental issues, there is little focus on them in brownfields redevelopment. In practice, the general assumptions are that brownfields redevelopment is an ideally situated policy issue for participatory planning. However, as this paper will illustrate through case study research, there are several situational prerequisites that must be met before there can be meaningful citizen participation in brownfields redevelopment. By highlighting these prerequisites, the author's goal is to mobilize research and policy efforts to overcome those limitations and to foster widespread meaningful participation in the redevelopment of brownfields in residential neighborhoods.     

Occurrence and determination of organic oxidants in rivers and wastewaters

Two iodometric methods for the concentration and analysis of water samples containing organic oxidants were applied to rivers and wastewaters in Illinois, Delaware, and Pennsylvania. Oxidant concentrations detected were as high as 2.5 § 10⁻⁵ M; the methods were capable of detecting as little as 10⁻⁸ M. Compounds possibly responsible for the observed oxidizing activity include N-chloro compounds, organic peroxides, or quinones.     

Contrasting structure and composition of the understory in species-rich tropical rain forests

In large samples of trees > or = 1 cm dbh (more than 1 million trees and 3000 species), in six lowland tropical forests on three continents, we assigned species with >30 individuals to one of six classes of stature at maturity (SAM). We then compared the proportional representation of understory trees (1-2 cm dbh) among these classes. The understory of the three Asian sites was predominantly composed of the saplings of large-canopy trees whereas the African and American sites were more richly stocked with trees of the smaller SAM classes. Differences in class representation were related to taxonomic families that were present exclusively in one continent or another. Families found in the Asian plots but not in the American plot (e.g., Dipterocarpaceae, Fagaceae) were predominantly species of the largest SAM classes, whereas families exclusive to the American plots (e.g., Melastomataceae sensu stricto, Piperaceae, and Malvaceae [Bombacacoidea]) were predominantly species of small classes. The African plot was similar to Asia in the absence of those American families rich in understory species, while similar to America in lacking the Asian families rich in canopy species. The numerous understory species of Africa were chiefly derived from families shared with Asia and/or America. The ratio of saplings (1-2 cm dbh) to conspecific canopy trees (>40 cm dbh) was lower in American plots than in the Asian plots. Possible explanations for these differences include phenology, moisture and soil fertility regimes, phyletic constraints, and the role of early successional plants in forest development. These results demonstrate that tropical forests that appear similar in tree number, basal area, and the family taxonomy of canopy trees nonetheless differ in ecological structure in ways that may impact the ecology of pollinators, dispersers, and herbivores and might reflect fundamental differences in canopy tree regeneration.     

Bridge building within the province of proactivity

The research questions posed in this study highlight the importance of valuing proactivity in both prompting an individual to engage in proactive behavior and encouraging the expression of that behavior. We integrate a variety of constructs from the proactivity literature to gain a deeper understanding of proactive behavior as it relates to proactive motivation and supervisory performance evaluations. First, we draw upon self‐determination theory, expectancy–value theory, and the recent integration of the proactive motivation literature to hypothesize that proactive behavior is predicted by the interaction of “can do” and “reason to” proactive motivational states. Second, on the basis of performance theory, we hypothesize that the relationship between proactive behavior and performance depends upon the extent to which the supervisor values proactivity. Specifically, we argue that supervisors with proactive personalities are more likely to value and reward subordinate proactive behavior than passive supervisors. Results provide support for both of our hypotheses. Interestingly, results show that proactive behavior did not result in negative consequences but rather that there was a cost (i.e., lower performance rating) for not taking charge for employees with proactive supervisors. Copyright © 2012 John Wiley & Sons, Ltd.     

A moderated mediation test of personality,coping, and health among deployed soldiers

Our study examines how personality and coping influence soldiers' psychological health among 648 US Army personnel who were at that time deployed in Iraq at the height of an insurgency. Conscientiousness, neuroticism, and extraversion were associated with different coping behaviors, and these were in turn related to psychological distress. Conscientiousness was positively associated with problem‐focused coping and negatively with avoidance coping, whereas neuroticism was most positively associated with avoidance coping. Extraversion was positively related to both seeking social support and avoidance coping. As expected, avoidance coping was positively associated with psychological distress. Coping style explained more variance in the relationship between personality and distress among soldiers who perceived higher levels of threat, thus supporting a moderated mediation hypothesis. We discuss implications for facilitating the stress coping of workers who face acute and potentially traumatic stress exposures. Copyright © 2011 John Wiley & Sons, Ltd.