A spatial analysis of phosphorus in the Mississippi river basin

Phosphorus (P) in rivers in the Mississippi River basin (MRB) contributes to hypoxia in the Gulf of Mexico and impairs local water quality. We analyzed the spatial pattern of P in the MRB to determine the counties with the greatest January to June P riverine yields and the most critical factors related to this P loss. Using a database of P inputs and landscape characteristics from 1997 through 2006 for each county in the MRB, we created regression models relating riverine total P (TP), dissolved reactive P (DRP), and particulate P (PP) yields for watersheds within the MRB to these factors. Riverine yields of P were estimated from the average concentration of each form of P during January to June for the 10-yr period, multiplied by the average daily flow, and then summed for the 6-mo period. The fraction of land planted in crops, human consumption of P, and precipitation were found to best predict TP yields with a spatial error regression model ( = 0.48, = 101). Dissolved reactive P yields were predicted by fertilizer P inputs, human consumption of P, and precipitation in a multiple regression model ( = 0.42, = 73), whereas PP yields were explained by crop fraction, human consumption of P, and soil bulk density in a spatial error regression model ( = 0.49, = 61). Overall, the Upper Midwest's Cornbelt region and lower Mississippi basin had the counties with the greatest P yields. These results help to point out specific areas where agricultural conservation practices that reduce losses to streams and rivers and point source P removal might limit the intensity or spatial occurrence of Gulf of Mexico hypoxia and improve local water quality.     

Dignity,face, and honor cultures: A study of negotiation strategy and outcomes in three cultures

This study compares negotiation strategy and outcomes in countries illustrating dignity, face, and honor cultures. Hypotheses predict cultural differences in negotiators' aspirations, use of strategy, and outcomes based on the implications of differences in self‐worth and social structures in dignity, face, and honor cultures. Data were from a face‐to‐face negotiation simulation; participants were intra‐cultural samples from the USA (dignity), China (face), and Qatar (honor). The empirical results provide strong evidence for the predictions concerning the reliance on more competitive negotiation strategies in honor and face cultures relative to dignity cultures in this context of negotiating a new business relationship. The study makes two important theoretical contributions. First, it proposes how and why people in a previously understudied part of the world, that is, the Middle East, use negotiation strategy. Second, it addresses a conundrum in the East Asian literature on negotiation: the theory and research that emphasize the norms of harmony and cooperation in social interaction versus empirical evidence that negotiations in East Asia are highly competitive. Copyright © 2016 John Wiley & Sons, Ltd.     

Biota Connect Aquatic Habitats throughout Freshwater Ecosystem Mosaics

Freshwater ecosystems are linked at various spatial and temporal scales by movements of biota adapted to life in water. We review the literature on movements of aquatic organisms that connect different types of freshwater habitats, focusing on linkages from streams and wetlands to downstream waters. Here, streams, wetlands, rivers, lakes, ponds, and other freshwater habitats are viewed as dynamic freshwater ecosystem mosaics (FEMs) that collectively provide the resources needed to sustain aquatic life. Based on existing evidence, it is clear that biotic linkages throughout FEMs have important consequences for biological integrity and biodiversity. All aquatic organisms move within and among FEM components, but differ in the mode, frequency, distance, and timing of their movements. These movements allow biota to recolonize habitats, avoid inbreeding, escape stressors, locate mates, and acquire resources. Cumulatively, these individual movements connect populations within and among FEMs and contribute to local and regional diversity, resilience to disturbance, and persistence of aquatic species in the face of environmental change. Thus, the biological connections established by movement of biota among streams, wetlands, and downstream waters are critical to the ecological integrity of these systems. Future research will help advance our understanding of the movements that link FEMs and their cumulative effects on downstream waters.     

Behavioral alterations due to diesel exhaust exposure

Several experiments examining the effects of diesel exhaust on the behavior of rats are reported. Animals were exposed either as adults or neonates. The spontaneous locomotor activity (SLA), measured in standard running wheel cages, of adult rats exposed for 8 h/day, 7 days/week was significantly less than that of controls. Experiments involving diesel exhaust exposure to neonatal rats indicated that adult rats, exposed to diesel exhaust during their neonatal lives, were significantly less active as measured by SLA. Adult rats, exposed to 20 h diesel per day as neonates, were placed in skinner boxes after the SLA experiment described above had been completed. The exhaust exposed animals showed significantly decreased acquisition of a food reinforced bar pressing task. All animals that learned this task extinguished at the same rate. The results of the neonatal diesel exhaust experiments support the hypothesis that diesel exhaust exposure during development of an organism can lead to behavioral differences in adulthood.     

Indigenous Studies Speaks to Environmental Management

This article describes the increasing connections between the fields of Indigenous studies and environmental management and examines some of the ways that an Indigenous studies perspective can guide thinking about environmental management. Indigenous groups have been involved in the management of environmental and natural resources on their lands since time immemorial. Indigenous groups have also become increasingly involved in Western practices of environmental management with the advent of co-management institutions, subsistence boards, traditional ecological knowledge forums, and environmental issues affecting Indigenous resources. Thus, it is an important time for scholarship that explores how Indigenous groups are both shaping and being affected by processes of environmental management. This article summarizes key findings and themes from eight papers situated at the intersection of these two fields of study and identify means by which environmental managers can better accommodate Indigenous rights and perspectives. It is the authors’ hope that increased dialog between Indigenous studies and environmental management can contribute to the building of sustainable and socially just environmental management practices.     

Economic and Technological Development in Climate Scenarios

Recent years have seen continuing debate about the factors underlying the process of economic development, but increasing consensus that technology and innovation play a key role. Increasing energy supplies are seen by some observers as fundamentally necessary for economic development, while others believe that a process of dematerialisation is underway in a shift to a "knowledge-based" economy. Energy futures will depend heavily on the process of technology innovation and transfer, which is affected by investment in research and development (R&D) and education, management styles and culture, market and regulatory incentives, perceived human needs, and many other factors. The primary energy carbon dioxide (CO2) emission intensity of the world economy has fallen by only about 1.1% per year in the last 20 years. However, circumstances are imaginable where energy intensity could decline by 2-3% per year in the long term. It is also possible that energy intensity could increase.     

Land Use, Spatial Scale, and Stream Systems: Lessons from an Agricultural Region

We synthesized nine studies that examined the influence of land use at different spatial scales in structuring biotic assemblages and stream channel characteristics in southeastern Minnesota streams. Recent studies have disagreed about the relative importance of catchment versus local characteristics in explaining variation in fish assemblages. Our synthesis indicates that both riparian- and catchment-scale land use explained significant variation in water quality, channel morphology, and fish distribution and density. Fish and macroinvertebrate assemblages can be positively affected by increasing the extent of perennial riparian and upland vegetation. Our synthesis is robust; more than 425 stream reaches were examined in an area that includes a portion of three ecoregions. Fishes ranged from coldwater to warmwater adapted. We suggest that efforts to rehabilitate stream system form and function over the long term should focus on increasing perennial vegetation in both riparian areas and uplands and on managing vegetation in large, contiguous blocks. Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsered by U.S. Geological Survey Biological Resources Division, the University of Minnesota, The Minnesota Department of Natural Resources, and the Wildlife Management Institute.     

Phylogeography of Australia’s king brown snake (Pseudechis australis) reveals Pliocene divergence and Pleistocene dispersal of a top predator

King brown snakes or mulga snakes (Pseudechis australis) are the largest and among the most dangerous and wide-ranging venomous snakes in Australia and New Guinea. They occur in diverse habitats, are important predators, and exhibit considerable morphological variation. We infer the relationships and historical biogeography of P. australis based on phylogenetic analysis of 1,249 base pairs from the mitochondrial cytochrome b, NADH dehydrogenase subunit 4 and three adjacent tRNA genes using Bayesian, maximum-likelihood, and maximum-parsimony methods. All methods reveal deep phylogenetic structure with four strongly supported clades comprising snakes from New Guinea (I), localities all over Australia (II), the Kimberleys of Western Australia (III), and north-central Australia (IV), suggesting a much more ancient radiation than previously believed. This conclusion is robust to different molecular clock estimations indicating divergence in Pliocene or Late Miocene, after landbridge dispersal to New Guinea had occurred. While members of clades I, III and IV are medium-sized, slender snakes, those of clade II attain large sizes and a robust build, rendering them top predators in their ecosystems. Genetic differentiation within clade II is low and haplotype distribution largely incongruent with geography or colour morphs, suggesting Pleistocene dispersal and recent ecomorph evolution. Significant haplotype diversity exists in clades III and IV, implying that clade IV comprises two species. Members of clade II are broadly sympatric with members of both northern Australian clades. Thus, our data support the recognition of at least five species from within P. australis (auct.) under various criteria. We discuss biogeographical, ecological and medical implications of our findings.Electronic Supplementary Material  Supplementary material is available in the online version of this article at     

Locomotor impairment and defense in gravid lizards (Eumeces laticeps): behavioral shift in activity may offset costs of reproduction in an active forager

Summary Female Eumeces laticeps experience a substantial decrease in running speed (ca. 25%) and an even greater loss of endurance (slightly over 50%) while gravid. Because some widely foraging lizards, including E. laticeps, rely primarily on running to escape predators, the decreases in speed and stamina may contribute to an increased risk of predation. However, observations suggest that gravid females become less active or conspicuous on the surface. Ambush foraging lizards rely relatively more on crypsis associated with immobility to avoid predation and thus can have greater average relative clutch mass (RCM) than active foragers. Behavioral compensation for locomotor impairment by becoming less active or conspicuous may allow some species the advantages inherent in both high relative clutch mass when gravid and the increased energetic profitability of active foraging when not gravid. As females gain weight during the breeding season, they may forage actively until the risk due to increasing locomotor impairment becomes too great and then change defensive strategy to greater reliance on crypsis. Without such a shift, widely foraging squamate reptiles may be less able than ambush foragers to exploit life-historical strategies demanding high current investment in reproduction.     

Direct and indirect effects of CO2, nitrogen, and community diversity on plant-enemy interactions

Resource abundance and plant diversity are two predominant factors hypothesized to influence the amount of damage plants receive from natural enemies. Many impacts of these environmental variables on plant damage are likely indirect and result because both resource availability and diversity can influence plant traits associated with attractiveness to herbivores or susceptibility to pathogens. We used a long-term, manipulative field experiment to investigate how carbon dioxide (CO2) enrichment, nitrogen (N) fertilization, and plant community diversity affect plant traits and the amount of herbivore and pathogen damage experienced by the common prairie legume Lespedeza capitata. We detected little evidence that CO2 or N affected plant traits; however, plants growing in high-diversity treatments (polycultures) were taller, were less pubescent, and produced thinner leaves (higher specific leaf area). Interestingly, we also detected little evidence that CO2 or N affect damage. Plants growing in polycultures compared to monocultures, however, experienced a fivefold increase in damage from generalist herbivores, 64% less damage from specialist herbivores, and 91% less damage from pathogens. Moreover, within diversity treatments, damage by generalist herbivores was negatively correlated with pubescence and often was positively correlated with plant height, while damage by specialist herbivores typically was positively correlated with pubescence and negatively associated with height. These patterns are consistent with changes in plant traits driving differences in herbivory between diversity treatments. In contrast, changes in measured plant traits did not explain the difference in disease incidence between monocultures and polycultures. In summary, our data provide little evidence that CO2 or N supply alter damage from natural enemies. By contrast, plants grown in monocultures experienced greater specialist herbivore and pathogen damage but less generalist herbivore damage than plants grown in diverse communities. Part of this diversity effect was mediated by changes in plant traits, many of which likely are plastic responses to diversity treatments, but some of which may be the result of evolutionary changes in response to these long-term experimental manipulations.