Impacts of Ammonium Sulfate Treatment on the Foliar Chemistry of Forest Trees at the Bear Brook Watershed in Maine

Foliar chemistry was examined in mature sugar maple (Acer saccharum Marsh), red maple (Acer rubrum L.), American beech (Fagus grandifolia Ehrh.), and red spruce (Picea rubens Sarg.) in response to chronic, watershed-level additions of ammonium sulfate [(NH4)2SO4]. Following four years of treatment, N concentrations were significantly higher in foliage from the treated watershed for all four species, with increases ranging from 6% in American beech to 33% in sugar maple. Sugar maple foliage from the treated watershed had significantly lower Ca concentrations (18%). Concentrations of K were significantly lower in beech (13%) and red spruce (9%) from the treated watershed. Foliar Mg was not different between watersheds. Aluminum concentrations were significantly higher in the foliage from the treated watershed for beech (18%), red maple (33%), and sugar maple (65%), but no differences in Al concentration occurred in current year red spruce foliage. Red spruce foliage resampled following a fifth year of treatment contained higher concentrations of N and Al and lower concentrations of Ca and Mg in the treated watershed. Despite these differences in red spruce foliar chemistry, wood production and density did not appear to be affected by the treatment.Differences in the foliar chemistry between the treated and untreated watershed may reflect the temporal and spatial integration of changes taking place in the soil of the treated watershed. Increased N is likely directly due to the N contained in the (NH4)2SO4 treatment. Labile Ca and other cations in the treated watershed would be expected to initially increase and then decrease in response to the treatment, with these changes beginning at the top of the forest floor. Thus, lower cation concentrations in foliage from the treated watershed may reflect the fact that cations in the uppermost portions of the soil were rapidly depleted, even though deeper soil layers were experiencing increased Ca release due to cation exchange effect of the acidification. The generally higher Al in foliage from the treated watershed is likely due to the mobilization of inorganic Al in the soil as has been reported previously for the treated watershed. Collectively these results suggest that the long-term deposition of acidifying substances containing N and S not only influence the cycling of N within these systems, but may also alter the cycling of other important nutrients and Al.     

Restoration of a Canadian Prairie Wetland with Agricultural and Municipal Wastewater

3 /day (800,000 US gallons) of municipal wastewater and beef processing wastewater. A large nongovernmental organization hastened restoration with a development process that outlined restoration goals and management objectives to satisfy a dual mandate of wastewater treatment and wildlife habitat creation. In 1995, after five years of wastewater additions, the basins had been refilled and the surrounding uplands had been acquired and restored. The Frank Lake Conservation Area currently provides high-quality habitat for a variety of wildlife in a region where many of the native plants and animals species have been lost due to habitat loss and fragmentation. The success of upland and water management strategies is reflected in the increase of target species' abundance and richness: 50 shorebird species, 44 waterfowl species, 15 raptor species, and 28 other new bird species have returned to the marsh since restoration. As well, significant N and P reduction occurs as waters flow through the first basin of the marsh. The management strategies of this project that satisfied a dual mandate serve as a model to guide managers of other large-scale wetland restoration projects.     

Aquatic plant community invasibility and scale-dependent patterns in native and invasive species richness

Invasive species richness often is negatively correlated with native species richness at the small spatial scale of sampling plots, but positively correlated in larger areas. The pattern at small scales has been interpreted as evidence that native plants can competitively exclude invasive species. Large-scale patterns have been understood to result from environmental heterogeneity, among other causes. We investigated species richness patterns among submerged and floating-leaved aquatic plants (87 native species and eight invasives) in 103 temperate lakes in Connecticut (northeastern USA) and found neither a consistently negative relationship at small (3-m2) scales, nor a positive relationship at large scales. Native species richness at sampling locations was uncorrelated with invasive species richness in 37 of the 60 lakes where invasive plants occurred; richness was negatively correlated in 16 lakes and positively correlated in seven. No correlation between native and invasive species richness was found at larger spatial scales (whole lakes and counties). Increases in richness with area were uncorrelated with abiotic heterogeneity. Logistic regression showed that the probability of occurrence of five invasive species increased in sampling locations (3 m2, n = 2980 samples) where native plants occurred, indicating that native plant species richness provided no resistance against invasion. However, the probability of three invasive species' occurrence declined as native plant density increased, indicating that density, if not species richness, provided some resistance with these species. Density had no effect on occurrence of three other invasive species. Based on these results, native species may resist invasion at small spatial scales only in communities where density is high (i.e., in communities where competition among individuals contributes to community structure). Most hydrophyte communities, however, appear to be maintained in a nonequilibrial condition by stress and/or disturbance. Therefore, most aquatic plant communities in temperate lakes are likely to be vulnerable to invasion.     

Assigning trend-based conservation status despite high uncertainty

Estimates of temporal trends in species’ occupancy are essential for conservation policy and planning, but limitations to the data and models often result in very high trend uncertainty. A critical source of uncertainty that degrades scientific credibility is that caused by disagreement among studies or models. Modelers are aware of this uncertainty but usually only partially estimate it and communicate it to decision makers. At the same time, there is growing awareness that full disclosure of uncertainty is critical for effective translation of science into policies and plans. But what are the most effective approaches to estimating uncertainty and communicating uncertainty to decision makers? We explored how alternative approaches to estimating and communicating uncertainty of species trends could affect decisions concerning conservation status of freshwater fishes. We used ensemble models to propagate trend uncertainty within and among models and communicated this uncertainty with categorical distributions of trend direction and magnitude. All approaches were designed to fit an established decision-making system used to assign species conservation status by the New Zealand government. Our results showed how approaches that failed to fully disclose uncertainty, while simplifying the information presented, could hamper species conservation or lead to ineffective decisions. We recommend an approach that was recently used effectively to communicate trend uncertainty to a panel responsible for setting the conservation status of New Zealand's freshwater fishes.     

Interactive effects of male and female age on extra-pair paternity in a socially monogamous seabird

Females sometimes obtain older sires for their offspring through extra-pair interactions, but how female age influences paternity is largely unexplored and interactive effects across the age span of both sexes have not been analyzed. To test whether female choice of sire age varies with female age in the blue-footed booby (Sula nebouxii), we examined associations between ages of both partners and the probability of extra-pair paternity (EPP) in 350 broods of parents up to 22 years old in a single breeding season. Extra-pair paternity enables a female to select an alternative sire for her offspring and could function to avoid or achieve particular combinations of parental ages. A male age?×?female age interaction revealed that in young females (≤4 years), EPP decreased with increasing age of the social partner, whereas in old females (≥8 years), it increased. Moreover, sires of extra-pair (EP) chicks of young females paired to young males were on average 6.33 years older than the females’ social partners. Since female boobies control copulatory access, this pattern could imply that young females choose old sires for their proven genetic quality and that old females avoid very old males because matings with them may risk infertility or genetic defects in offspring. Taking female age into account and observing across the whole age span may be necessary for understanding female age-based mate choice.     

Media and bushfires: A community perspective of the media during the Grampians Fires 2006

This paper examines the ways residents in the Grampians area in the Australian state of Victoria used their local and their state and national based media before, during and after the 2006 bushfires (wildfires). The researchers were particularly concerned to understand how residents evaluated media sources as trustworthy and credible in relation to bushfire warnings and information about the fires delivered in the media.

Analysis of data derived from two separate focus group sessions conducted by the researchers reveals four main themes. (1) The media are perceived as part of a broader information gathering process. (2) Local knowledge is the most important aspect in broadcast information. (3) Members of small communities can feel disenfranchised and resentful of the media when media coverage focuses on larger towns, and (4) the effects of media reporting, including specific warnings, are both immediate and long lasting.

The paper explores some of the tensions that result from the ways rural residents use and distinguish between local/regional and metropolitan and out-of-state bushfire information; and it encourages better use of the local/regional media to increase community safety and awareness in relation to bushfire mitigation, preparedness and crisis management issues before, during and after the fires. It is suggested that risk communications professionals need to understand that when mediated risk-related communications are provided, a key evaluative criterion is whether or not those media and the messages represent and reflect local knowledge.     

Indirect effects of a key ecosystem engineer alter survival and growth of foundation coral species

Stegastes nigricans, a "farmerfish" that cultivates algal turf and defends territories from grazers and other intruders, can affect coral indirectly due to increased competition with farmed algal turf and/or reduced predation resulting from territorial aggression directed at corallivores. To investigate the indirect effects of this key ecosystem engineer on coral mortality and growth, we transplanted caged and exposed fragments of four coral species to patch reefs in French Polynesia on which we manipulated the presence of S. nigricans and turf, and to reefs naturally devoid of S. nigricans. Reef access was two to four times higher for herbivorous fishes, and two times higher for corallivorous fishes, when S. nigricans was removed, indicating that reef access is reduced for two important guilds of fishes when S. nigricans is present. Stegastes' territoriality indirectly benefited delicate acroporids (Montipora floweri and Acropora striata), yielding a twofold to fivefold reduction in skeletal loss due to lower predation frequencies in the presence of S. nigricans. Three corals, A. striata, M. floweri, and especially Porites australiensis, suffered mortality due to overgrowth significantly more frequently in the presence of farmed turf, but Pocillopora verrucosa did not. Algal abundance predicted the frequency of overgrowth for only A. striata and P. australiensis. M. floweri were more likely to be overgrown when exposed (uncaged) in the presence of S. nigricans, suggesting an interaction modification, in this case that initial predation increased susceptibility to competition with turf. In this community, the presence of S. nigricans may increase algal overgrowth of massive Porites by facilitating its turf competitors and simultaneously reduce predation of branching corals through territorial exclusion of corallivores. These indirect interactions may underlie previously documented community transitions from disturbance-resistant massive coral to recovering branching corals within S. nigricans territories.     

Captive Breeding and Reintroduction Evaluation Criteria: a Case Study of Peninsular Bighorn Sheep

Abstract: Captive breeding and reintroduction programs are rarely evaluated, and assessment criteria vary widely. We used the following criteria to evaluate a bighorn sheep ( Ovis canadensis ) augmentation program: (1) survival and recruitment rates in the captive population, (2) survival of released animals, (3) recruitment of released animals, (4) growth rate of the reintroduced or augmented population, and (5) establishment of a viable wild population. Captive bighorn survival and recruitment was high, averaging 0.98 (SD = 0.05) and 71.0% (SD = 19.4), respectively. Annual survival of free-ranging captive-reared bighorn ( n = 73, x = 0.80, SD = 0.11) did not differ (   Z = −0.85, p = 0.40; n = 14) from survival of wild-reared bighorn ( n = 43, x = 0.81, SD = 0.12). Recruitment was unusually low for both captive-reared (  x = 13.7%, SD = 0.24) and wild-reared ewes (  x = 13.7%, SD = 0.20). Although reintroduction did not result in population growth or establishment of a viable population, it helped prevent extirpation of the reinforced deme, preserved metapopulation linkage, and aided habitat preservation. Chronic low recruitment and low adult survivorship precluded achievement of criteria 3–5. Environmental conditions in the release area also appeared to hinder program success. Standard evaluation criteria for ongoing reintroductions allow for informative assessments and facilitate comparisons needed to refine reintroduction science as a recovery tool for threatened or endangered populations.     

Assimilation of 210Po by the mussel Mytilus edulis from the alga Isochrysis galbana

Marine invertebrates are thought to accumulate ²¹⁰Po primarily from their food. In this study, a pulse-chase methodology was used to examine the assimilation and depuration of ²¹⁰Po by Mytilus edulis from the common marine alga Isochrysis galbana. The digestion of ²¹⁰Po from I. galbana occurred via a biphasic process, characteristic of a rapid (extracellular) and slow (intracellular) digestion typical of marine bivalves. The mantle/gill and foot have no known digestive role, yet their ²¹⁰Po specific activities increased after 24 h. It is proposed that this increase in ²¹⁰Po specific activity was related to ²¹⁰Po being incorporated into these tissues from ²¹⁰Po assimilated from I. galbana during extracellular digestion. It is proposed that the linear loss of ²¹⁰Po previously accumulated by control mussels was related to the continual state of renewal and replacement of cellular proteins, with ²¹⁰Po turnover and metabolism governed by protein turnover and metabolism. M. edulis' assimilation efficiency of ²¹⁰Po from the ²¹⁰Po-labelled alga was calculated to be 17.2 ± 2.1%, and thus similar to that of Ag, Cd, Co, Se and Zn by bivalves from other marine algae species. It is proposed that the assimilation efficiency of ²¹⁰Po is a function of protein assimilation. Received: 27 August 1998 / Accepted: 3 September 1999     

Comparison of recidivism rates for a teenage trauma prevention program after the addition of high-fidelity patient simulation

Objectives: We evaluated the benefits of adding high-fidelity simulation to a teenage trauma prevention program to decrease recidivism rates and encourage teens to discuss actionable steps toward safe driving.

Methods: A simulated pediatric trauma scenario was integrated into an established trauma prevention program. Participants were recruited because they were court-ordered to attend this program after misdemeanor convictions for moving violations. The teenage participants viewed this simulation from the emergency medical services (EMS) handoff to complete trauma care. Participants completed a postsimulation knowledge assessment and care evaluation, which included narrative data about the experience. Qualitative analysis of color-coded responses identified common themes and experiences in participants' answers. Court records were reviewed 6 years after course completion to determine short- and long-term recidivism rates, which were then compared to our program's historical rate.

Results: One hundred twenty-four students aged 16–20 years participated over a 2-year study period. Narrative responses included general reflection, impressions, and thoughts about what they might change as a result of the course. Participants reported that they would decrease speed (30%), wear seat belts (15%), decrease cell phone use (11%), and increase caution (28%). The recidivism rate was 55% within 6 years. At 6 months it was 8.4%, at 1 year it was 20%, and it increased approximately 5–8% per year after the first year. Compared with our programs, for historical 6-month and 2-year recidivism rates, no significant difference was seen with or without simulation.

Conclusions: Adding simulation is well received by participants and leads to positive reflections regarding changes in risk-taking behaviors but resulted in no changes to the high recidivism rates This may be due to the often ineffectiveness of fear appeals.