Climate change and the cost of conserving species in Madagascar

We examined the cost of conserving species as climate changes. We used a Maxent species distribution model to predict the ranges from 2000 to 2080 of 74 plant species endemic to the forests of Madagascar under 3 climate scenarios. We set a conservation target of achieving 10,000 ha of forest cover for each species and calculated the cost of achieving this target under each scenario. We interviewed managers of projects to restore native forests and conducted a literature review to obtain the net present cost per hectare of management actions to maintain or establish forest cover. For each species, we added hectares of land from lowest to highest cost per additional year of forest cover until the conservation target was achieved throughout the time period. Climate change was predicted to reduce the size of species' ranges, the overlap between species' ranges and existing or planned protected areas, and the overlap between species' ranges and existing forest. As a result, climate change increased the cost of achieving the conservation target by necessitating successively more costly management actions: additional management within existing protected areas (US$0-60/ha); avoidance of forest degradation (i.e., loss of biomass) in community-managed areas ($160-576/ha); avoidance of deforestation in unprotected areas ($252-1069/ha); and establishment of forest on nonforested land within protected areas ($802-2710/ha), in community-managed areas ($962-3226/ha), and in unprotected areas ($1054-3719/ha). Our results suggest that although forest restoration may be required for the conservation of some species as climate changes, it is more cost-effective to maintain existing forest wherever possible.     

Science–policy processes for transboundary water governance

In this policy perspective, we outline several conditions to support effective science–policy interaction, with a particular emphasis on improving water governance in transboundary basins. Key conditions include (1) recognizing that science is a crucial but bounded input into water resource decision-making processes; (2) establishing conditions for collaboration and shared commitment among actors; (3) understanding that social or group-learning processes linked to science–policy interaction are enhanced through greater collaboration; (4) accepting that the collaborative production of knowledge about hydrological issues and associated socioeconomic change and institutional responses is essential to build legitimate decision-making processes; and (5) engaging boundary organizations and informal networks of scientists, policy makers, and civil society. We elaborate on these conditions with a diverse set of international examples drawn from a synthesis of our collective experiences in assessing the opportunities and constraints (including the role of power relations) related to governance for water in transboundary settings.     

Are all experiments created equal? A framework for analysis of the learning potential of policy experiments in environmental governance

Environmental changes are increasing the need to understand complex cross-scale feedbacks in social–ecological systems. However, consistent conceptualisation of learning associated with environmental governance is lacking, and research mainly centres on individual variables. This paper identifies a typology of such learning, and theorises about configurations of variables. Focusing on experimentation as an intervention geared towards learning, it proposes a definition of policy experiment. A theoretical framework is presented, summarising a typology of experiments based on learning-related variables embedded in design choices, and reflected in institutional rule aggregations. The framework facilitates systematic analysis of real-world cases and testing of hypotheses on the effects of different types of experiment on learning. A case study demonstrates application of the framework. Results suggest future research paths that include attention to additional relevant variables. The findings have relevance for scholars interested in experimentation and learning, and environmental policy-makers considering experimentation to assess policy innovations.     

Bird Communities of Prairie Uplands and Wetlands in Relation to Farming Practices in Saskatchewan

Abstract: Modern farm practices can vary in their emphasis on tillage versus chemicals to control weeds, and researchers know little about which emphasis has greater ecological benefits. We compared avifaunas of uplands and wetlands in four treatments: conventional farms, conservation farms (contrasting those that minimized frequency of tillage [minimum tillage] with those that eliminated chemical inputs [organic]), and restored or natural (wild) sites in Saskatchewan, Canada. Of 37 different upland bird species encountered during surveys, one made greater use of farms, four made greater use of wild sites, and the remaining species showed no preference. When all upland species were combined, higher relative abundance occurred on wild than on farm sites, and on minimum tillage than on conventional farms. Wild upland sites also had more species than did conventional farms. Of 79 different species encountered during surveys of wetlands and their margins, most had similar encounter probabilities among treatments, although seven were more common on either organic farms or wild sites. Higher relative abundances were documented in wetland habitat of wild sites and organic farms than of minimum tillage or conventional farms. Wetlands of wild sites had more species than did minimum tillage or conventional farms. Overall, in terms of both avifaunal density and diversity, small treatment effects could be ascribed to differences between conventional and conservation farms, whereas larger effects were due to differences between farms and wild sites. Wetlands were heavily used by birds in all treatments, suggesting high conservation priority regardless of context.     

Owner and floater red-winged blackbirds: determinants of status

Summary We used sequential removal experiments to test whether the resource-holding potential (RHP) of territory owner red-winged blackbirds, Agelaius phoeniceus, was superior to that of their first replacements (shallow floaters) and subsequent replacements (deep floaters). Among the removals were secondyear males, which were morphologically inferior to adults and which also tended to be competitively inferior in aviary contests. The highest proportion of secondyear males occurred in the deep floater class. Thus, the RHP of some deep floaters was inferior to that of owners and shallow floaters. However, among adults, owners, shallow floaters, and deep floaters had equivalent morphological and competitive RHP. Furthermore, replacement males that had defended territories for many days were neither morphologically nor competitively superior to males that had defended territories for only a few days. Our results suggest that RHP distinguishes adults from second-year males, but does not separate owners from floaters. The only hypothesis that is potentially supported by our observations is that owners have a greater expected payoff from their territory than intruders, and in this way owners are able to maintain site dominance. The nature of that payoff remains to be determined. Offprint requests to: P.J. Weatherhead     

An investigation into the likely impact of oxy-coal retrofit on fire-side corrosion behavior in utility boilers

Real-time electrochemical measurements of corrosion rate were performed to evaluate the respective corrosion rates of one boiler waterwall material (SA210) and three boiler superheater materials (T22, P91 and 347H) while firing Utah Western bituminous, Illinois high-sulfur bituminous and Powder River Basin (PRB) sub-bituminous coals in a 1.5 MW pulverized coal-fired furnace. The raw average measured corrosion rates were very low, between 0.0003 and 0.016 mm/year (0.012 and 0.63 mils/year) for most materials under air- and oxy-fired conditions. For some high-sulfur conditions measured corrosion rates were as high as 0.72 mm/year (28 mils/year). Waterwall corrosion rates decreased consistently when converting from air- to oxy-firing while superheater corrosion rates generally increased, although they were less than twice the air-fired rate under most conditions. Corrosion rates for the lower alloyed materials (SA210 and T22) increased significantly during transients from reducing to oxidizing conditions. Measured increases in the corrosion rate of 347H material under high sulfur and low temperature conditions, and associated decrease in corrosion rate at higher temperatures on this alloy, were consistent with the formation of trisulphates in the superheater deposits. The increase of corrosion rate with increased metal temperatures was demonstrated, as was the consistently repeatable nature of the observed results.     

Time and recruitment costs as currencies in manipulation studies on the costs of reproduction

Life history theory predicts that parents will have lower Darwinian fitness if they tend clutches that are above or below the size they naturally produce. We experimentally tested for relationships between fitness and clutch size in Tree Swallow (Tachycineta bicolor) offspring and parents. Over 130 trios of nests initiated on the same day were randomly divided among reduce (-3 eggs), control (3 eggs picked up and replaced), or add (+3 eggs) manipulations. Pre-manipulation modal clutch size was six eggs (range before manipulations was 1-10; afterwards, it was 1-11). Hatching took longer in larger clutches, but the proportion of eggs hatching and fledging was similar for clutches from 4 to 10, so that clutches of 10 produced the maximum number of fledgling. Parental feeding rates were higher for larger broods, but per capita feeds to nestlings were fewer, and nestlings were smaller. Nonetheless, survival of both young and adults, based on recaptures in subsequent years, was not significantly affected by manipulations. Manipulations also had no significant effect on subsequent reproduction, including the number of fledglings produced by either local recruits or returning breeders. Collectively, our results failed to detect fitness costs associated with tending larger clutches for either parents or the offspring reared and suggested directional selection for larger clutch size. However, because clutches that hatch later produce fewer recruits, the extra days required to lay more eggs and to fledge extra young may eliminate a large part of the advantage that would accrue to parents producing enlarged clutches. For example, our data suggest that there may be less than a 16% benefit to producing nine instead of six eggs, rather than 50%, as is suggested by experimentally manipulated egg numbers alone. Thus, time, rather than costs of reproduction, may be the crucial constraint selecting against Tree Swallows laying larger clutches.