A critical variable in the estimation of gross primary production of terrestrial ecosystems light-use efficiency (LUE), a value that represents the actual efficiency of a plant's use of absorbed radiation energy to produce biomass. Light-use efficiency is driven by the most limiting of a number of environmental stress factors that reduce plants' photosynthetic capacity; these include short-term stressors, such as photoinhibition, as well as longer-term stressors, such as soil water and temperature. Modeling LUE from remote sensing is governed largely by the biochemical composition of plant foliage, with the past decade seeing important theoretical and modeling advances for understanding the role of these stresses on LUE. In this article we provide a summary of the tower-, aircraft-, and satellite-based research undertaken to date, and discuss the broader scalability of these methods, concluding with recommendations for ongoing research possibilities.

Taxonomy, the description and classification of life's diversity, is a discipline that underpins all biological sciences. Current gaps in taxonomic knowledge and expertise restrict our ability to effectively conserve and manage biodiversity. Among vertebrates, amphibians are of particular concern; they are highly threatened yet poorly known. We found that resident expertise in amphibian taxonomy is concentrated in economically rich but relatively species-poor countries in North America and Europe. However, much expertise is exported; most experts work on species elsewhere, in biodiverse Asia or South America. Unexpectedly, age pyramids of taxonomists revealed healthy levels of participation among young researchers, though available expertise remains inadequate across most of the globe. Our results strongly suggest that many amphibian species are becoming extinct before they are described, and provide concrete support for the widespread calls to increase taxonomic expertise worldwide.

A high proportion of global coverage by protected areas is composed of relatively few very large protected areas (vLPAs); it is therefore important to understand their contribution to biological conservation. Here, using fresh analyses and a review of literature, we examine five particular contentions about existing terrestrial vLPAs: that they (1) are highly biased in environmental coverage, (2) contain low numbers of overall and rare species, (3) make limited contributions toward meeting global conservation prioritization schemes, (4) contain substantial areas of wilderness, and (5) are relatively immune to threatening processes. These contentions are generally supported. The principal contribution of vLPAs is substantial global coverage of wilderness, and more broadly, of areas where human influence is much reduced. There is also some evidence that individual vLPAs can retain unusually intact species assemblages and significant populations of particular species of regional or global conservation concern, and they can have marked regional conservation significance. The current level of threat to many vLPAs, and the challenges for their management, therefore are substantive concerns.

Ocean acidification is likely to have direct negative physiological consequences for many marine organisms, and cause indirect effects on marine ecosystems. Ocean acidification could also affect the oceans' current role as a net carbon sink by altering the oceanic calcium carbonate budget. Although ocean acidification and climate change are both caused by greenhouse gas emissions, ocean acidification is not climate change per se, and is often referred to as “the other carbon dioxide (CO₂) problem.” As the United States considers actions in response to climate change, it is critical to take into account not only the impact of CO₂ emissions on the climate but also their ramifications for ocean chemistry. The metrics that currently guide the climate change debate are dominated by strategies to reduce thermal impacts on the terrestrial environment. In this article, I examine the effects of ocean acidification and why they should help guide decisionmakers in setting CO₂ emissions goals.

Crawfish frogs (Lithobates areolatus) base their nonbreeding activities in and around the entrances of crayfish burrows. This site preference allows individual crawfish frogs to be monitored using still and video imaging techniques. We used three camera types offering different continuities, scales, and resolutions of data to observe the frogs' activity patterns and nonbreeding behaviors. Together, these techniques allowed us to observe two behaviors in crawfish frogs previously unreported for amphibians: (1) circumdiel activity patterns, and (2) long periods (days) of surface activity. Although these behavioral findings are at this time specific to crawfish frogs, we suspect that they may not be unusual activity patterns for other frogs, as well. The use of imaging techniques that take advantage of these frogs' dependence on burrows and use of burrow entrances has allowed us to observe these patterns for the first time.

There is a vigorous debate about the capacity of conservation biology, as a scientific discipline, to effectively contribute to actions that preserve and restore biodiversity. Various factors may be responsible for the current great divide that exists between conservation research and action. Part of the problem may be a lack of involvement by conservation scientists in actually conducting or helping implement concrete conservation actions, yet scientists' involvement can be decisive for successful implementation, as illustrated here by the rapid recovery of an endangered hoopoe population in the Swiss Alps after researchers decided to implement the corrective measures they were proposing themselves. We argue that a conceptual paradigm shift should take place in the academic conservation discipline toward more commitment on the part of researchers to turn conservation science into conservation action. Practical implementation should be regarded as an integrated part of scientific conservation activity, as it actually constitutes the ultimate assessment of the effectiveness of the recommended conservation guidelines, and should be rewarded as such.

The meaningful incorporation of independent scientific advice into effective public policy is a hurdle for any conservation legislation. Canada's Species at Risk Act (SARA; 2002) was designed to separate the science-based determination of a species' risk status from the decision to award it legal protection. However, thereafter, the input of independent science into policy has not been clearly identifiable. Audits of SARA have identified clear deficiencies in the protection and recovery of luted species; for example, of the 176 species legally protected in 2003, only one has a legal implementation plan for its recovery. We argue that clearly distinguishing science from policy at all relevant stages would improve the scientific integrity, transparency, accountability, and public acceptance of the legal listing and recovery implementation processes in SARA. Such delineation would also clarify exactly what trade-offs are being made between at-risk species recovery and competing policy objectives.