• Energy Research
• Closed Access close
• Restricted close
• Embargo close
• USC Research Bank research data close

Abstract Lianas (woody vines) are an important component of tropical forests, with a strong impact on forest dynamics, but their responses during forest succession have received relatively little attention. Here, we present an analysis of the changes in stem density, biomass, and species richness of lianas and self-supporting plants during tropical forest succession. We surveyed lianas ≥0.5 cm diameter at breast height (dbh) and self-supporting plants ≥2.5 cm dbh in 0.1 ha inventory plots in a chronosequence of 30 sites in northeastern Costa Rica, 23 sites on abandoned pastures 10–44 years of age, and seven sites in old-growth forest. Stem density of self-supporting plants showed no predictable chronosequence trend, but liana stem density declined significantly with forest age. Aboveground biomass of self-supporting vegetation increased rapidly during succession, with forests 31–44 years exhibiting higher levels of biomass than old-growth forests. Liana biomass accumulated more slowly, with the highest levels in old-growth sites. Species richness of self-supporting vegetation increased significantly during succession, but species richness of lianas showed no change or a slight decline with forest age, depending on the method of assessment. The differences between tree and liana responses during succession stem from the unique physiology and life history traits of lianas.

Arctic ecosystems are already experiencing and responding to climate change. Inuit communities are highly dependent on the natural environment for their livelihoods, and hence are particularly sensitive to the effects of climate change. Community-based studies across the Canadian Arctic have identified several widespread vulnerabilities. Subsistence hunting is susceptible to changes in wildlife populations and access to hunting areas; permafrost degradation has implications for community infrastructure and for coastal erosion; changes in the availability of harvested food contribute an additional risk to people s health; the erosion of environmental knowledge and land skills enhances the vulnerability of Inuit hunters to climate risks; and economic opportunities may come with more shipping, but may be constrained by closed ice roads and limits on the sport hunting industry.

We demonstrate use of the ratio of red to far-red (R:FR) light in assessing understory light levels in tropical forests. We determined the sensitivity of the ratio to bias when used under a variety of light conditions. We also calibrated the relationship between percent transmittance, as measured with traditional paired-instrument methods, and the R:FR ratio under a wide range of canopy cover conditions. Finally, we used the relationship to measure light levels under a closed canopy in a secondary tropical wet forest and assessed the usefulness of the measurements in determining spatial structure of light in a 1 ha plot, compared with percent transmittance values. Across a wide range of canopy conditions, red:far-red ratios explained 97% of the variation in percent diffuse transmittance under cloudy skies. Predictions of percent transmittance made under sunny skies were consistently lower than those made during cloudy conditions, even under a closed canopy, indicating that the method can be used reliably only with diffuse light. We used the R:FR ratio to characterize the spatial structure in understory light levels in a wet tropical forest in Costa Rica, explaining more variation in spatial structure than did a model fit to percent transmittance at a height of 1.5 m. The ratio provides a quick way to assess with high sensitivity the quantity and quality of light without the inconvenience and potential errors that can be introduced with the use of paired instruments or hemispherical photographs.

A major reason for writing this book is to describe the evidence for last-millennium climate change and its effects on environments and societies from the Pacific Basin, a commonly marginalized region in global syntheses. The paucity of palaeoclimate datasets from the southern hemisphere has often been remarked upon, and many palaeoclimatologists have cautioned that their statements about global last-millennium (and earlier) climate change should be regarded as preliminary until a better balance is achieved. Yet there is also a marked west-east hemispheric imbalance between the Pacific third of the Earth and elsewhere, largely because the Pacific is mostly ocean, but also because there have been fewer scientific investigations of its recent palaeoclimatic history. In seeking to redress these imbalances, this book utilizes data about Pacific Basin palaeoclimate from numerous sources. Many of these data are imprecise, their relationships to presumed climate drivers often uncertain. For such reasons, some of the conclusions reached about last-millennium Pacific Basin climates are less compelling than would be ideal, not just for comparing with other parts of the world but also for testing whether or not particular changes were global in extent, globally or hemispherically synchronous, or otherwise constrained in time or space. Yet there are more than adequate data to produce a first synthesis for this vast and poorly researched region, a synthesis that the author regards as sufficiently compelling to command the attention of geoscientists, climatologists, geographers, archaeologists, anthropologists, sociologists and historians interested in the Pacific. It is important to recognize that in the Pacific Basin – as in other parts of the world – the study of last-millennium climates is constrained by the effective reach of particular techniques back in time. Obviously, the last hundred years or so, for which there are instrumental records of climate in many places, is the least controversial time period. Beyond the reach of such directly monitored data series, it is necessary to use proxy data. There are three types of proxy used: those that directly proxy climate variables (typically temperature and precipitation), those that proxy climate through an environmental filter and finally those that proxy either climate or climate-driven environmental changes through changes in human societies. [Book Synopsis]

Abstract Researchers dealing with pavements and experts on materials have been increasingly focused on the structural strength of the pavement materials without paying sufficient attention to the environment and cultural norms. In the 21st century, the concept of pavement design and rehabilitation needs to be modified owing to new requirements such as the additional structural loads derived from the climate change, environmental challenges, social requirements, and aging population. Therefore, the concept of post-modern pavement (PMP) was proposed to address the structural, sustainability, and socio-psychological requirements. In this review of the state-of-the-art, the potential of the interlocking concrete block pavement (ICBP) was evaluated based on its laboratory and field structural performance, sustainability, and social acceptance as a PMP in Japan. Therefore, the relevant literature in English and Japanese, including journals, conference proceedings, technical reports, books, and theses, over a span of 47 years (1971–2018), were studied. It was found that the structural and functional performances of the ICBP in different facilities were satisfying. Furthermore, owing to its waste material use, less noise emission, air purifying characteristics, and heat island reduction, the environmental performance of ICBP was in harmony with sustainable practices. In addition, pavements users, both able and differently abled, rated the ICBP as a more appropriate pavement system owing to its physical appearance, serviceability, aesthetic features, lower heat island effect, rapid maintenance, and positive psychologic effects after earthquake and tsunami events. As a result, the ICBP can be recommended as a PMP for the design and development of resilient transportation infrastructure assets in Japan.

Wood biomass is turned into industrial fuel through chipping. The efficiency of chipping depends on many factors, including chipper knife wear. Chipper knife wear was determined through a long-term follow-up study, conducted at a waste wood recycling yard. Knife wear determined a sharp drop of productivity (>20%) and a severe decay in product quality. Dry sharpening with a grinder mitigated this effect, but it could not replace proper wet sharpening. Increasing the frequency of wet sharpening sessions determined a moderate increase of knife depreciation cost, but it could drastically enhance machine performance and reduce biomass processing cost. Since benefits largely exceed costs, increasing the frequency of wet sharpening sessions may be an effective measure for reducing overall chipping cost. If the main goal of a chipper operator is to increase productivity and/or decrease fuel consumption, then managing knife wear should be a primary target. (C) 2014 Elsevier Ltd. All rights reserved.

A survey documenting how climate change is perceived, experienced, and responded to in the Canadian mining sector was administered to industry practitioners at the Prospectors & Developers Association of Canada annual meeting. Nine key findings from the survey are discussed: (1) The Canadian mining sector is sensitive to climate-related conditions. (2) Climate change is perceived to be having a negative impact on mining operations. (3) Companies are taking action to manage the current impacts. (4) Cost and uncertainty are commonly identified barriers to adapting to current climate change. (5) Future climate change is expected to have impacts for the industry. (6) Climate change projections are perceived as threats by the majority of respondents. (7) Despite the perceived threat, companies are not currently taking action to plan for future impacts. (8) Cost and uncertainty are commonly identified barriers to adapting to future climate change impacts. (9) The mining sector is currently making efforts to reduce greenhouse gas emissions. The survey is exploratory in nature, establishing a baseline for targeted research to assess in greater detail the vulnerability of mining to climate change.

Pacific Island countries are particularly vulnerable to future manifestations of climate change due to high coastline‐to‐land‐area ratios, and high dependence of inhabitants on natural ecosystems. While everyone in the Pacific Islands should participate in climate change adaptation activities, it is the young people, given they are the generation likely to not only bear the burden of climate change, but to lead and live effective climate change adaptation activities and strategies specific to their region, the involvement of youth is critical. Pacific Island youths are often marginalised within traditional decision‐making hierarchies, therefore they are typically excluded from participating in meaningful discussions at community and government levels. Discussions were held with 30 adolescents aged 14–18 years in Fiji to explore knowledge and experiences regarding climate change. Participants revealed their dismay at their inability to talk to family – who they consider are not doing enough – about what they consider as appropriate responses to climate change, recommending the help of an authoritative outsider who could speak to their community leaders and family. Discussions also revealed that Fijian youth could not distinguish between changes in the climate and normal weather events, attesting to the importance of climate‐change education and awareness‐raising efforts within the Pacific Islands more generally.

Micro-algae are seen as one of the major future fuel sources. Culture and growth of oil rich micro-algae and catalytic process for the conversion of their crude oils or biomass is reviewed here. While there is a significant literature on growth and extraction of oil from the resultant biomass the literature on the problems of refining these oils is diverse and needs collation. It is clear that previous work has been focused on the two green algae Botryococcus braunii and Chlorella protothecoides containing terpenoid hydrocarbons and glyceryl lipids as their major crude oils, respectively, both of which will need different refinery technology for upgrading. Studies show a number of conventional catalysts in the petroleum refining industry including transition metals, zeolites, acid and base catalysts can be used with variable effect. These have been employed for cracking, hydrocracking, liquefaction, pyrolysis and transesterification processes to produce diesel, jet fuel and petrol (gasoline). However there is strong evidence that new nano-scale materials containing a high number of active sites and high surface areas may offer more potential.