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PubMed2005

Environmental alternatives for rural development: the case of Oaxaca, Mexico.

This article examines various environmental alternatives within the context of forest resource-dependent communities of the State of Oaxaca, Mexico. Two main objectives were to describe particular rural development routes among different Mexican communities, and to explain why certain environmental options for rural development are selected over others. While many communities choose either sustainable or illegal logging options in Oaxaca, some may decide against logging of any kind. Four principal forest-based community categories, according to a government forest classification scheme, are discussed in the context of environmental alternatives for this article. Based on this typology, two "integrated forest management" communities in the Sierra Norte of Oaxaca are described and compared. One community's decision not to log within a shared land arrangement has caused significant tensions in the region. Key findings illustrate the extent to which rural communities can make appropriate environmental decisions and examines their effects on environmental and social sustainability. Increased rural involvement in environmental decision-making is called for, since rural residents are those most likely to appreciate nearby natural resources as a source of sustainable livelihoods. It is expected that this research may be applicable to rural areas of other countries.

Conservation of Natural Resources↗
PubMed2001

Documentation of hazards and safety perceptions for mechanized logging operations in East Central Alabama.

The logging industry remains one of the most hazardous in the nation. Despite more stringent safety regulations and improvements in equipment safety features, the rate of logging fatalities has decreased at a much lower rate than the decrease in the rate of illnesses and injuries in the same occupation. The objective of this research was to identify and assess the hazards associated with logging operations in the Southeast region of the U.S. and propose interventions, taking into consideration the fact that, currently, most operations in the region are fully mechanized. Five logging crews in East Central Alabama participated in the study and were observed repeatedly during their normal operations. Researchers observed loggers engaging in multiple unsafe behaviors, but none of those led to an injury. The incidence of unsafe behaviors may be due in part to a lack of awareness of the hazards. Results indicate that Occupational Safety and Health Administration (OSHA) regulations appear to have little influence on logging safety. Loggers believe that most safety training recommendations are difficult to implement and negatively impact productivity. Thus, there seem to be fundamental drawbacks in the logging industry regarding effective delivery of safety training to loggers. The present study was a joint venture by the Industrial and Systems Engineering and Psychology departments of Auburn University, with support from the United States Forest Service (USFS).

Accidents, Occupational↗
PubMed2005

Health consequences of forest fires in Indonesia.

We combined data from a population-based longitudinal survey with satellite measures of aerosol levels to assess the impact of smoke from forest fires that blanketed the Indonesian islands of Kalimantan and Sumatra in late 1997 on adult health. To account for unobserved differences between haze and nonhaze areas, we compared changes in the health of individual respondents. Between 1993 and 1997, individuals who were exposed to haze experienced greater increases in difficulty with activities of daily living than did their counterparts in nonhaze areas. The results for respiratory and general health, although more complicated to interpret, suggest that haze had a negative impact on these dimensions of health.

Activities of Daily Living↗
PubMed2005

Assessing hemlock decline using visible and near-infrared spectroscopy: indices comparison and algorithm development.

Near-infrared reflectance spectroscopy was evaluated for its effectiveness at predicting pre-visual decline in eastern hemlock trees. An ASD FieldSpec Pro FR field spectroradiometer measuring 2100 contiguous 1-nm-wide channels from 350 nm to 2500 nm was used to collect spectra from fresh hemlock foliage. Full spectrum partial least squares (PLS) regression equations and reduced stepwise linear regression equations were compared. The best decline predictive model was a 6-term linear regression equation (R2= 0.71, RMSE = 0.591) based on: Carter Miller Stress Index (R694/R760), Derivative Chlorophyll Index (FD705/FD723), Normalized Difference Vegetation Index ((R800 - R680)/(R800 + R680)), R950, R1922, and FD1388. Accuracy assessment showed that this equation predicted an 11-class decline rating with a 1-class tolerance accuracy of 96% and differentiated healthy trees from those in very early decline with 72% accuracy. These results indicate that narrow-band sensors could be developed to detect very early stages of hemlock decline, before visual symptoms are apparent. This capability would enable land managers to identify early hemlock woolly adelgid infestations and monitor forest health over large areas of the landscape.

Algorithms↗
PubMed2006

Mapping the economic costs and benefits of conservation.

Resources for biodiversity conservation are severely limited, requiring strategic investment. Understanding both the economic benefits and costs of conserving ecosystems will help to allocate scarce dollars most efficiently. However, although cost-benefit analyses are common in many areas of policy, they are not typically used in conservation planning. We conducted a spatial evaluation of the costs and benefits of conservation for a landscape in the Atlantic forests of Paraguay. We considered five ecosystem services (i.e., sustainable bushmeat harvest, sustainable timber harvest, bioprospecting for pharmaceutical products, existence value, and carbon storage in aboveground biomass) and compared them to estimates of the opportunity costs of conservation. We found a high degree of spatial variability in both costs and benefits over this relatively small (approximately 3,000 km(2)) landscape. Benefits exceeded costs in some areas, with carbon storage dominating the ecosystem service values and swamping opportunity costs. Other benefits associated with conservation were more modest and exceeded costs only in protected areas and indigenous reserves. We used this cost-benefit information to show that one potential corridor between two large forest patches had net benefits that were three times greater than two otherwise similar alternatives. Spatial cost-benefit analysis can powerfully inform conservation planning, even though the availability of relevant data may be limited, as was the case in our study area. It can help us understand the synergies between biodiversity conservation and economic development when the two are indeed aligned and to clearly understand the trade-offs when they are not.

Biodiversity↗
PubMed2001

Genetic improvement of poplar feedstock quality for ethanol production.

Opportunities for matching chemical and physical properties of woody feedstocks to ethanol production process requirements via genetic improvement have long been recognized. Exploitation is now feasible owing to advances in trait measurement, breeding, and gene transfer technologies. Poplar genetic parameters are favorable largely for reducing lignin and increasing cellulose contents and specific gravity. Transgenic poplars with decreased lignin and increased cellulose contents, but otherwise normal growth and development, have been produced via genetic transformation. The long-standing debate on feasibility has thus become one of when, not if, designer varieties will become available.

Biomass↗
PubMed2005

Incorporation of competitive effects in forest tree or animal breeding programs.

Competition among domesticated plants or animals can have a dramatic negative impact on yield of a stand or farm. The usual quantitative genetic model ignores these competitive interactions and could result in seriously incorrect breeding decisions and acerbate animal well-being. A general solution to this problem is given, for either forest tree breeding or penned animals, with mixed-model methodology (BLUP) utilized to separate effects on the phenotype due to the individuals' own genes (direct effects) and those from competing individuals (associative effects) and thereby to allow an optimum index selection on those effects. Biological verification was based on two lines of Japanese quail selected for 6-week weight; one line was selected only for direct effects (D-BLUP) while the other was selected on an optimal index for both direct and associative effects (C-BLUP). Results over 23 cycles of selection showed that C-BLUP produced a significant positive response to selection (b=0.52+/-0.25 g/hatch) whereas D-BLUP resulted in a nonsignificant negative response (b=-0.10+/-0.25 g/hatch). The regression of percentage of mortality on hatch number was significantly different between methods, decreasing with C-BLUP (b=-0.06+/-0.15 deaths/hatch) and increasing with D-BLUP (b=0.32+/-0.15 deaths/hatch). These results demonstrate that the traditional D-BLUP approach without associative effects not only is detrimental to response to selection but also compromises the well-being of animals. The differences in response show that competitive effects can be included in breeding programs, without measuring new traits, so that costs of the breeding program need not increase.

Animals↗
PubMed2001

Quantification of anthropogenic threats to lakes in a lowland county of central Sweden.

An evaluation of the negative effects caused by anthropogenic influence on lake ecosystems was performed, using data from 143 catchments in Uppsala County, Sweden. The study included i) technical encroachments; i.e. construction of dams, dikes, etc. as well as effects of drainage of land; ii) pollution, i.e. eutrophication, acidification, and contamination by toxic substances; iii) introduction of nonnative species; and iv) exploitation of species populations. Severe damage was caused mostly by drainage of land followed by pollution by toxic substances and, to a smaller extent, introduction of nonnative species and eutrophication. Most lakes were subject to several types of disturbances, interacting in a complex pattern, which made it difficult to link the visible effects to the true causes of the disturbance. Future lake management should include analyses of all disturbances to the lake catchments, taking into account the historical perspective, in order to balance the threats/damages, in an analysis of the possibilities for maintaining biodiversity and sustainability in the ecosystems.

Animals↗
PubMed2001

Social cost-benefit analysis of a watershed development project in Karnataka, India.

Watershed Development Programmes (WDPs) have been initiated in India to improve and sustain productivity and the production potential of the dry and semiarid regions of the country at higher levels, through adoption of appropriate production and conservation techniques. The aim is also to meet the needs of rural communities for food, fuel, fodder, and timber and, thereby, reduce pressure on natural forests. In view of their potential for growth, for improving income, and the natural resource base of the disadvantaged regions of the country, WDPs are being accorded importance in the development plans for India and by donor agencies. This paper presents a social cost-benefit appraisal of a watershed development project in Karnataka, India. Using alternate viability measures, i.e. Net Present Value (NPV), Benefit-Cost Ratio (BCR) and Internal Rate of Return (IRR), and rigorous tests and sensitivity analyses, the results show that if expected full benefits are realized, the benefits derived from the watershed project are quite high, with the IRRs ranging from 19 to 96%. If, however, expected full benefits were to fall short by 25%, and net costs of (including the opportunity cost of grazing benefits foregone by the villagers on account of establishing community woodlots on degraded forestlands and village commons used earlier for free grazing of their cattle) the project will report losses. Even these losses can be contained if the direct benefits from some community woodlots, for which information was not available, and other indirect benefits, mostly of an environmental nature, are included. The findings of this study suggest that watershed development projects initiated to improve the economy and ecology of India's dry and semiarid regions are economically viable and socially desirable.

Agriculture↗
PubMed2001

The economic importance of products extracted from Amazonian flood plain forests.

Rural people in the Peruvian Amazon practice agriculture and extract a wide range of products from natural forests, rivers and lakes. Their diversified livelihood system includes fish, game, and plant products. In 2 flood-plain villages, data for one year have been collected to compare the economy of local agriculture with the economy of extracted forest products for subsistence as well as for commerce. The study includes both fauna (game and fish) and flora (timber as well as nontimber). The results show that extracted forest products for subsistence, especially fish, are a main factor in the local economy. The daily net income from extraction activities exceeds both income from cultivation and the normal daily wages for unskilled workers, emphasizing the need for thorough socioeconomic investigations before any alternative land-use option is implemented. The average value per ha of natural forest used for extraction is in the order of USD 13 yr-1, and the average extraction area is 113 ha household-1. When yield from agriculture is included in the calculations, the total per ha value of current extraction and agricultural activities increases to USD 21 yr-1.

Agriculture↗
PubMed2002

Ozone dynamics and deposition processes at a deforested site in the Amazon basin.

The goal of this study is to investigate the impact of deforestation on ozone dynamics and deposition in the Brazilian Amazon basin. This goal is accomplished through i) analyses of ozone levels and deposition rates at a deforested site during the rainy season; and ii) comparisons of these data with similar information derived at a forest. At the pasture site maximum ozone mixing ratios reach 20 parts per billion on a volume basis (ppbv) but about 6 ppbv prevail over the forest. Maximum ozone deposition velocities for pastures can reach 0.7 cm s-1, which is about threefold lower than values derived for forests. Combining ozone abundance and deposition velocities, pasture maximum ozone fluxes reach approximately 0.2 microgram (ozone) m-2 s-1. This flux represents approximately 70% of the deposition rates measured over the forest. Hence, this study suggests that conversion of rainforests to pastures could lead to a net reduction (30%) in the ozone sink in the Amazon.

Agriculture↗
PubMed2002

Perspectives on secondary forest management in tropical humid lowland America.

Secondary forests regrowing on abandoned agricultural land constitute an important, albeit widely overlooked, component in the landscape matrix of tropical lowland America. These 'new' forest resources on private land-holdings derive either from unsustainable cattle-ranching practices of better-off farmers or are part of the crop/fallow system of resource-poor farmers. If previous land use was light, secondary forest management may offer an interesting use option to better-off farmers, providing that subsidies for stand improvement are given. Improved fallow systems using partly the successional vegetation may be a way to establish sustainable small-scale agriculture for resource-poor farmers. Given some technical and financial input, land-use systems based on secondary vegetation could play a vital role both in sustainable landscape management and biodiversity conservation.

Agriculture↗
PubMed2002

Indigenous knowledge informing management of tropical forests: the link between rhythms in plant secondary chemistry and lunar cycles.

This research used knowledge of the indigenous practice of timing nontimber forest product harvest with the full moon to demonstrate that chemicals controlling the decomposition rate of foliage fluctuate with the lunar cycle and may have developed as a result of plant-herbivore interactions. Indigenous knowledge suggests that leaves harvested during the full moon are more durable. Palm leaves harvested during the full moon had higher total C, hemicellulose, complex C and lower Ca concentrations. These chemical changes should make palm leaves less susceptible to herbivory and more durable when harvested during the full moon. This study proposes a mechanism by which plants in the tropics minimize foliage herbivory and influence the decomposition rates of senesced leaves and their durability, especially during the full moon. This research supports the need to use natural life cycles in managing forests and provides a scientific basis for an indigenous community's harvesting practice.

Animals↗
PubMed2003

Assessment of management-dependent nutrient losses in tropical industrial tree plantations.

Industrial tree plantations in the tropics usually follow short rotations and intensive site management including slash and burn, and the use of heavy machinery. We attempt to quantify the implied nutrient losses (harvest export, erosion, slash and burn, leaching) in order to give plantation managers a chance to understand the significance of their planning and decisions. We used the scarce globally available information and a case study plantation in East Kalimantan, Indonesia (Acacia mangium and Eucalyptus deglupta). Adaptation involves problems and is discussed in some detail. Results are approximate only. Assuming a harvest volume of 200 m3 ha(-1), we assessed a loss of 427-680 kg ha(-1) N, 12-13 kg ha(-1) P, 178-252 kg ha(-1) Ca, 276-370 kg ha(-1) K, and 45-57 kg ha(-1) Mg per rotation. Of this overall loss, stand harvest accounted for 18-29% (N), 21-30% (P), 56-26% (K), 48-64% (Ca) and 22-37% (Mg). This means that the cumulative loss by erosion, slash and burn, and leaching exceeds that of the harvest. These losses can be influenced by management.

Acacia↗
PubMed2003

Terrestrial ecosystem recovery--modelling the effects of reduced acidic inputs and increased inputs of sea-salts induced by global change.

The reduced emissions of acidifying sulfur and nitrogen in Europe since the late 1970s will be further reduced when the Gothenburg protocol is fully implemented by 2010. Here we address the consequences for the recovery of acidified terrestrial ecosystems using the acidification model MAGIC applied to 3 large-scale "clean rain" experiments, the so-called roof experiments at Risdalsheia, Norway; Gårdsjön, Sweden, and Klosterhede, Denmark. Implementation of the Gothenburg protocol will initiate recovery of the soils at all 3 sites by rebuilding base saturation. The rate of recovery is small and base saturation increases less than 5% over the next 30 years. A climate-induced increase in storm severity will increase the sea-salt input to the ecosystems. This will provide additional base cations to the soils and more than double the rate of the recovery, but also lead to strong acid pulses following high sea-salt inputs as the deposited base cations exchange with the acidity stored in the soil. Future recovery of soils and runoff at acidified catchments will thus depend on the amount and rate of reduction of acid deposition, and in the case of systems near the coast, the frequency and intensity of sea-salt episodes as well.

Acid Rain↗