An introduction to digital methods in remote sensing of forested ecosystems: Focus on the Pacific Northwest,USA

Aerial photography has been routinely used for several decades by natural resource scientists and managers to map and monitor the condition of forested landscapes. Recently, along with the emergence of concepts in managing forests as ecosystems, has come a significant shift in emphasis from smaller to larger spatial scales and the widespread use of geographic information systems. These developments have precipitated an increasing need for vegetation information derived from other remote sensing imagery, especially digital data acquired from high-elevation aircraft and satellite platforms. This paper introduces fundamental concepts in digital remote sensing and describes numerous applications of the technology. The intent is to provide a balanced, nontechnical view, discussing the shortcomings, successes, and future potential for digital remote sensing of forested ecosystems.     

Implications of mangrove dynamics for private and use in bragança, north Brazil: a case study

This work analyses effects of recent variations in the tidal inundation frequency in a mangrove ecosystem in the Bragança peninsula, North Brazil, and its implications for land occupation and use. Field data, time series of remote sensing images and local legislation were analysed focusing on the potential socio-economic impact of a changing environmental setting due to a rise in relative sea level. In the investigated period (1972–1997), vegetation changes along the coastline indicate net losses of mangrove coverage. In the central part of the peninsula, a topographically higher herbaceous plain constituting part of a farm presents an active progression of mangrove forest into an area previously dominated by grasses and herbs. This area measured 8.8 km² in 1972 but was gradually reduced to 5.6 km² in 1997, while progressively replaced by a monospecific stand of the black mangrove,Avicennia germinans. A linear extrapolation indicates that the elevated plain may be completely covered by mangrove by 2035. Current Brazilian legislation prohibits the extraction of mangrove trees without an officially approved management plan. Thus, the usable area of the farm has suffered a reduction by ca. 36% over 25 yr and we predict that is could be entirely replaced by mangroves in the next 35 yr. In this case study, legislation and ecosystem characteristics are analysed and a management plan discussed which could represent income alternatives for affected resource users at the local and regional level.     

The validation of a passive sampler for indoor and outdoor concentrations of volatile organic compounds

Volatile organics compounds (VOCs) are ubiquitous in the air we breathe. The use of passive samplers to measure these concentrations can be an effective technique. When exposed for long durations, a passive sampler may be a good tool for investigating chronic exposures to chemicals in the environment. A passive sampler that was designed for occupational exposures can be used as such a tool. Laboratory validation under as many conditions as possible needs to be accomplished so as to characterize the sampler with known parameters. This paper describes the methods and results of an investigation into the validity of using a passive monitor to sample VOCs for a three-week period. Two concentration levels, two relative humidities, and five VOCs were studied. Results indicate that the samplers work best under conditions of high concentration with low relative humidity and low concentration with high relative humidity. For the passive sampler, excluding chloroform, percent deviations from the predicted values varied between -41 and +22 percent; while the values between the passive and the active samplers varied between -27 and +24 percent. Benzene, heptane, and perchloroethylene were sampled with equal precision and accuracy.     

Rapid karyotyping in ectopic pregnancies

The aim of this study was to determine the feasibility of karyotyping ectopic Fallopian tube pregnancies utilizing dividing cytotrophoblast cells. Villi from 78 ectopic conceptuses were processed by the direct chromosome technique and cytogenetic diagnosis was successful in 60 cases (76-9 per cent). The amount of villi obtained, as well as villus morphology, was correlated with cytogenetic success rate. Histological examination of the Fallopian tube was also carried out. A total of 47 cases were chromosomally abnormal (78-3 per cent), which is the highest frequency of cytogenetic abnormalities reported to date.     

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.     

Using NDVI to Assess Vegetative Land Cover Change in Central Puget Sound

We used the Normalized Difference Vegetation Index (NDVI) in the rapidly growing Puget Sound region over three 5-year time blocks between 1986–1999 at three spatial scales in 42 Watershed Administrative Units (WAUs) to assess changes in the amounts and patterns of green vegetation. On average, approximately 20% of the area in each WAU experienced significant NDVI change over each 5-year time block. Cumulative NDVI change over 15 years (summing change over each 5-year time block) was an average of approximately 60% of each WAU, but was as high as 100% in some. At the regional scale, seasonal weather patterns and green-up from logging were the primary drivers of observed increases in NDVI values. At the WAU scale, anthropogenic factors were important drivers of both positive and negative NDVI change. For example, population density was highly correlated with negative NDVI change over 15 years (r = 0.66, P < 0.01), as was road density (r = 0.71, P < 0.01). At the smallest scale (within 3 case study WAUs) land use differences such as preserving versus harvesting forest lands drove vegetation change. We conclude that large areas within most watersheds are continually and heavily impacted by the high levels of human use and development over short time periods. Our results indicate that varying patterns and processes can be detected at multiple scales using changes in NDVIa values.     

Characterizing heat stress on livestock using the temperature humidity index (THI)—prospects for a warmer Caribbean

There is an urgent need to mitigate climate change-induced heat stress in livestock and poultry in the Caribbean, given the deleterious effects it has on food and nutrition security. The temperature humidity index (THI) was used to assess the potential for heat stress on four types of livestock and poultry (broiler and layer chickens, pigs and ruminants) for three different agro-ecological locations in Jamaica. The THI was formulated specifically to each livestock type and was examined for 2001–2012 for seasonal and annual patterns of variability. Differences in THI were observed between summer (July to September) and winter (December to February) with some moderation due to agro-ecological location. Our results suggest that animals in ambient field conditions in Jamaica may already be experiencing considerable periods of heat stress even during the relatively cooler northern hemisphere winter months. Future patterns of heat stress relative to a 1961–1990 baseline were derived from a regional climate model when mean global surface air temperature is 1.5, 2.0 and 2.5 °C above pre-industrial levels. At 1.5 °C, marked increases were noted in THI and almost persistent year-round heat stress is projected for Caribbean livestock. Conditions will be exacerbated at the higher global warming states. Possible response strategies such as cooling technologies are discussed.