-
Roles and Effects of Environmental Carbon Dioxide in Insect Life
-
Carbon dioxide (CO2) is a ubiquitous sensory cue that plays mul- tiple roles in insect behavior. In recent years understanding of the well-known role of CO2 in foraging by hematophagous insects (e.g., mosquitoes) has grown, and research on the roles of CO2 cues in the foraging and oviposition behavior of phytophagous insects and in behavior of social insects has stimulated interest in this area of insect sensory biology. This review considers those advances, as well as some of the mechanistic bases of the modulation of behavior by CO2 and important progress in our understanding of the detection and CNS processing of CO2 information in insects. Finally, this review briefly addresses how the ongoing increase in atmospheric CO2 levels may affect insect life.
Located in
Resources
/
Climate Science Documents
-
What Every Conservation Biologist Should Know about Human Population
-
EDITORIAL:CONCLUDING PARAGRAPH:
As with population issues, conservation biologists should ensure that we, as individuals and a professional society, understand the current state of knowledge about consumption and encourage constructive dialogues on consumption and its effects on biodiversity. We are not the first to highlight the issue of consumption (Baltz 1999) in this journal. Although conservation biologists may debate whether U.S. consumption is excessive (Ehrlich & Goulder 2007), the answer is more clear to some. Two months after the 2011 Society for Conservation Biology meeting mentioned above, the first author was in India attending a presentation by Elinor Os- trom (2012), who won the Nobel Prize for her work on management of the commons. At the end of the presentation, a participant asked Dr. Ostrom how we can get the world to talk about consumption as the root cause of the world’s environmental problems. This is the question conservation biologists should ask more often.
Located in
Resources
/
Climate Science Documents
-
Editorial: The “New Conservation”
-
EDITORIAL: OPENING PARAGRAPHS A powerful but chimeric movement is rapidly gaining recognition and supporters. Christened the “new conservation,” it promotes economic development, poverty alleviation, and corporate partnerships as surrogates or substitutes for endangered species listings, protected areas, and other mainstream conservation tools. Its proponents claim that helping economically disadvantaged people to achieve a higher standard of living will kindle their sympathy and affection for nature. Because its goal is to supplant the biological diversity–based model of traditional conservation with something entirely different, namely an economic growth–based or humanitarian movement, it does not deserve to be labeled conservation.
Located in
Resources
/
Climate Science Documents
-
The floodplain large-wood cycle hypothesis: A mechanism for the physical and biotic structuring of temperate forested alluvial valleys in the North Pacific coastal ecoregion
-
A ‘floodplain large-wood cycle’ is hypothesized as a mechanism for generating landforms and influencing river dynamics in ways that structure and maintain riparian and aquatic ecosystems of forested alluvial river valleys of the Pacific coastal temperate rainforest of North America. In the cycle, pieces of wood large enough to resist fluvial transport and remain in river channels initiate and stabilize wood jams, which in turn create alluvial patches and protect them from erosion. These stable patches provide sites for trees to ma- ture over hundreds of years in river valleys where the average cycle of floodplain turnover is much briefer, thus providing a future source of large wood and reinforcing the cycle. Different tree species can function in the floodplain large-wood cycle in different ecological regions, in different river valleys within regions, and within individual river valleys in which forest composition changes through time. The cycle promotes a physically complex, biodiverse, and self-reinforcing state. Conversely, loss of large trees from the system drives landforms and ecosystems toward an alternate stable state of diminished biogeomorphic complexity. Reestablishing large trees is thus necessary to restore such rivers. Although interactions and mechanisms may differ between biomes and in larger or smaller rivers, available evidence suggests that large riparian trees may have similarly fundamental roles in the physical and biotic structuring of river valleys elsewhere in the temperate zone. Wood debris Riparian forest Fluvial geomorphology Foundation species Biogeomorphology River restoration
Located in
Resources
/
Climate Science Documents
-
Highly episodic fire and erosion regime over the past 2,000 y in the Siskiyou Mountains, Oregon
-
Fire is a primary mode of natural disturbance in the forests of the Pacific Northwest. Increased fuel loads following fire suppression and the occurrence of several large and severe fires have led to the perception that in many areas there is a greatly increased risk of high-severity fire compared with presettlement forests. To recon- struct the variability of the fire regime in the Siskiyou Mountains, Oregon, we analyzed a 10-m, 2,000-y sediment core for charcoal, pollen, and sedimentological data. The record reveals a highly episodic pattern of fire in which 77% of the 68 charcoal peaks before Euro-American settlement cluster within nine distinct peri- ods marked by a 15-y mean interval. The 11 largest charcoal peaks are significantly related to decadal-scale drought periods and are followed by pulses of minerogenic sediment suggestive of rapid sediment delivery. After logging in the 1950s, sediment load was increased fourfold compared with that from the most severe presettlement fire. Less severe fires, marked by smaller charcoal peaks and no sediment pulses, are not correlated significantly with drought periods. Pollen indicators of closed forests are consistent with fire-free periods of sufficient length to maintain dense forest and indicate a fire-triggered switch to more open conditions during the Medieval Climatic Anomaly. Our results indicate that over millennia fire was more episodic than revealed by nearby shorter tree-ring records and that recent severe fires have precedents during earlier drought episodes but also that sediment loads resulting from logging and road building have no precedent in earlier fire events. historical fire | climate variability | ecological resilience | logging | sediment charcoal
Located in
Resources
/
Climate Science Documents
-
Forest commons and local enforcement
-
This article examines the relationship between local enforcement and forests used as commons. It uses a unique multicountry dataset, created over the past 15 years by the International Forestry Resources and Institutions Research Program. Drawing on original enforcement and forest commons data from 9 countries, we find that higher levels of local enforcement have a strong and positive but complex relationship to the probability of forest regeneration. This relationship holds even when the influence of a number of other factors such as user group size, subsistence, and commercial importance of forests, size of forest, and collective action for forest improvement activities is taken into account. Although several of the above factors have a statistically signifi- cant relationship to changes in the condition of forest commons, differences in levels of local enforcement strongly moderate their link with forest commons outcomes. The research, using data from diverse political, social, and ecological contexts, shows both the importance of enforcement to forest commons and some of the limits of forest governance through commons arrangements.
governance sustainability collective action local institutions forest regeneration
Located in
Resources
/
Climate Science Documents
-
Faustian bargains? Restoration realities in the context of biodiversity offset policies
-
The science and practice of ecological restoration are increasingly being called upon to compensate for the loss of biodiversity values caused by development projects. Biodiversity offsetting—compensating for losses of biodiversity at an impact site by generating ecologically equivalent gains elsewhere—therefore places substantial faith in the ability of restoration to recover lost biodiversity. Furthermore, the increase in offset-led restoration multiplies the consequences of failure to restore, since the promise of effective restoration may increase the chance that damage to biodiversity is permitted. But what evidence exists that restoration science and practice can reliably, or even feasibly, achieve the goal of ‘no net loss’ of biodiversity, and under what circumstances are successes and failures more likely? Using recent reviews of the restoration ecology literature, we examine the effectiveness of restoration as an approach for offsetting biodiversity loss, and conclude that many of the expectations set by current offset policy for ecological restoration remain unsupported by evidence. We introduce a conceptual model that illustrates three factors that limit the technical success of offsets: time lags, uncertainty and measurability of the value being offset. These factors can be managed to some extent through sound offset policy design that incorporates active adaptive management, time discounting, explicit accounting for uncertainty, and biodiversity banking. Nevertheless, the domain within which restoration can deliver ‘no net loss’ offsets remains small. A narrowing of the gap between the expectations set by offset policies and the practice of offsetting is urgently required and we urge the development of stronger links between restoration ecologists and those who make policies that are reliant upon restoration science. Keywords:Compensatory habitat - Conservation policy - Mitigation banking - Environmental risk - No net loss - Restoration success
Located in
Resources
/
Climate Science Documents
-
Reliability of Indicators of Decline in Abundance
-
Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a population or species meets criteria for conservation action (false negative) or may incorrectly show that such criteria have been met (false positive). To quantify the rate of both types of error for 20 com- monly used indicators of declining abundance (threat indicators), we used receiver operating characteristic curves derived from historical (1938–2007) data for 18 sockeye salmon (Oncorhynchus nerka) populations in the Fraser River, British Columbia, Canada. We retrospectively determined each population’s yearly status (reflected by change in abundance over time) on the basis of each indicator. We then compared that popu- lation’s status in a given year with the status in subsequent years (determined by the magnitude of decline in abundance across those years). For each sockeye population, we calculated how often each indicator of past status matched subsequent status. No single threat indicator provided error-free estimates of status, but indicators that reflected the extent (i.e., magnitude) of past decline in abundance (through comparison of current abundance with some historical baseline abundance) tended to better reflect status in subsequent years than the rate of decline over the previous 3 generations (a widely used indicator). We recommend that when possible, the reliability of various threat indicators be evaluated with empirical analyses before such indicators are used to determine the need for conservation action. These indicators should include estimates from the entire data set to take into account a historical baseline.
Located in
Resources
/
Climate Science Documents
-
The payoff of conservation investments in tropical countryside
-
The future of biodiversity and ecosystem services hinges on har- monizing agricultural production and conservation, yet there is no planning algorithm for predicting the efficacy of conservation investments in farmland. We present a conservation planning framework for countryside (working agricultural landscapes) that calculates the production and conservation benefits to the current baseline of incremental investments. Our framework is analogous to the use of reserve design algorithms. Unlike much countryside modeling, our framework is designed for application in data- limited contexts, which are prevalent. We apply our framework to quantify the payoff for Costa Rican birds of changing farm plot and border vegetation. We show that installing windbreaks of native vegetation enhances both bird diversity and farm income, espe- cially when complementing certain crop types. We make predic- tions that differ from those of approaches currently applied to agri-environment planning,: e.g., although habitat with trees has lower local species richness than farm plot habitats (1– 44% lower), replacing any plot habitat with trees should boost regional rich- ness considerably. Our planning framework reveals the small, targeted changes on farms that can make big differences for biodiversity.
biodiversity conservation planning countryside biogeography ecological-economic models matrix
Located in
Resources
/
Climate Science Documents
-
THE COST OF LEAFING
-
Understanding the trade-offs involved for plants making leaves promises fresh insights on every scale from the plant to the planet, finds John Whitfield.
Excerpt: One definition of economics is the study choice under the constraint of scarcity, and the narrowrangeofchoicesintheleafeconomics
spectrum provides a vivid illus- tration of the various scarcities that dominate plants’ lives. The fact that all leaves lie fairly close to the axis of the spectrum shows that, despite the vast diversity of foliage produced over hundreds of millions of years of evolution, plants have little room for manoeuvre in
how they build their leaves. “Most textbooks of ecology project the idea that there’s an almost infinite diversity of organisms,” says plant ecologist Philip Grime of the University of Sheffield, UK. “But if you look at the core biology of what organisms do with resources, you find severe constraints and trade-offs.”
Located in
Resources
/
Climate Science Documents
