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PubMed1997

Relationship between subjective neck disorders and cervical spine mobility and motion-related pain in male machine operators.

STUDY DESIGN: In a single blinded procedure, quantified cervical clinical tests were performed on machine operators with and without subjective reports of neck pain. OBJECTIVES: To evaluate whether subjective reports of neck pain are associated with limited and painful cervical spine mobility. SUMMARY OF BACKGROUND DATA: Spinal motion evaluation and pain rating are commonly used for assessing impairment in patients with spinal disorders. However, it is still unclear how cervical spinal motion and corresponding pain rating are affected by subjective reports of neck pain. METHODS: Forty-nine male forest machine operators completed the Standardized Nordic questionnaire on musculoskeletal symptoms. Maximal voluntary cervical spinal flexion-extension, bilateral axial rotation, and lateral flexion were measured with a goniometer ad modum Myrin, while corresponding pain was rated on Borg's scale. RESULTS: Nineteen men (38.8%) reported no neck pain within the past 12 months, nine men (18.4%) reported pain during the past 12 months (but not during the past 7 days), and 21 men (42.8%) had experienced neck pain during the past 7 days. The results of two of the range-of-motion tests (flexion and left axial rotation) and three of the pain ratings (during flexion, extension, and left axial rotation) differed significantly between men who reported pain the past 7 days and those with no pain, and they correlated significantly with the severity of pain as reported in the questionnaire. CONCLUSIONS: Many forest machine operators reporting neck pain in the Nordic questionnaire did have limited and painful cervical spine mobility. Range-of-motion tests may be useful tools to describe impairment and constitute a basis for assessment for therapeutic interventions.

Adult↗
PubMed1997

A descriptive analysis of nonfatal occupational injuries to older workers, using a national probability sample of hospital emergency departments.

An estimated 136,985 nonfatal, work-related injuries to workers 55 years of age and older were presented for treatment in hospital emergency departments across the United States during 1993. Men accounted for 63.7% of the injuries and had an injury rate of 1.06 per 100 workers, compared with a rate of 0.76 among women. Among the oldest workers (65+ years), injuries were more likely to be fractures or dislocations, to result from falls on the same level, or to involve hospitalization. The services industry had the largest number of injuries (31.9%), whereas the highest injury rate occurred in the agriculture/forestry/fishing industry (1.50 per 100 workers). The types of injuries most frequently requiring hospitalization were fractures or dislocations that resulted from a fall. Because older workers' employment demographics and injury patterns differ from the remainder of the labor force, interventions need to be developed which are specific to the workplace for this older working population.

Accidental Falls↗
PubMed1999

Nonfatal logging-related injuries in West Virginia.

A survey was conducted via mail among West Virginia certified loggers to determine the number of nonfatal, logging-related injuries received during the past 12 months that required medical attention or restricted job ability. Loggers were asked to describe injuries, safety training, and protective equipment use. Thirty percent (546/1816) responded to the survey, and 9% (42/481) of those directly involved in logging operations reported injuries. Leading cause of injury was being struck by a falling tree or limb (29%); leading body parts injured were the leg/knee/hip (31%); and the most common type of injury was bruising (43%). Seventy-six percent of the injured sought medical treatment. A majority reported using some type of protective equipment including hard hats, safety shoes, and goggles. Loggers reported that training in the proper use of equipment and machinery; use of a safety plan, acting on worker suggestions, and landing talks might improve safety.

Accidents, Occupational↗
PubMed2002

In-season physiological and biochemical status of reforestation workers.

Tree-planting demands sustained high work-output and is associated with high injury rates but has not been characterized previously. Data were collected from 10 male planters after 19 +/- 5 (T1) and 37 +/- 5 days (T2) of planting. One severe infection and one knee strain injury were noted. Loads carried were 32% +/- 5% body mass and heart rates were between 60% to 75% of maximum for 57% +/- 26% of the planting shift. A loss of 1.7% +/- 1.5% body mass occurred, although intake exceeded 5000 kcal/day. From 8% (T1) to 27% (T2) of postprandial blood glucose samples were found to be < 3.3 mmol/L. Further evidence of the cumulative stress was seen in increased levels of resting cortisol (428 +/- 163 to 741 +/- 103 mmol/L), norepinephrine (2.09 +/- 1.34 to 3.09 +/- 1.05 mmol/L), and creatine kinase (184 +/- 82 to 397 +/- 174 U/L) at T2. The postactivity neutrophilia and lymphophilia (absolute count, CD4+ and CD8+) observed at T1 were blunted at T2. The implications of mild hypoglycemia, including possible effects on cognitive and motor function, warrant further study.

Adult↗
PubMed1999

Similar non-random processes maintain diversity in two tropical rainforests.

Quadrat-based analysis of two rainforest plots of area 50 ha, one in Panama (Barro Colorado Island, BCI) and the other in Malaysia (Pasoh), shows that in both plots recruitment is in general negatively correlated with both numbers and biomass of adult trees of the same species in the same quadrat. At BCI, this effect is not significantly influenced by treefall gaps. In both plots, recruitment of individual species is negatively correlated with the numbers of trees of all species in the quadrats, but not with overall biomass. These observations suggest, but do not prove, widespread frequency-dependent effects produced by pathogens and seed-predators that act most effectively in quadrats crowded with trees. Within-species correlations of mortality with numbers or biomass are not found in either plot, indicating that most frequency-dependent mortality takes place before the trees reach 1 cm in diameter. Stochastic effects caused by BCI's more rapid tree turnover may contribute to a larger variance in diversity from quadrat to quadrat at BCI, although they are not sufficient to explain why BCI has fewer than half as many tree species as Pasoh. Finally, in both plots quadrats with low diversity show a significant increase in diversity over time, and this increase is stronger at BCI. This process, like the frequency-dependence, will tend to maintain diversity over time. In general, these non-random forces that should lead to the maintenance of diversity are slightly stronger at BCI, even though the BCI plot is less diverse than the Pasoh plot.

Ecosystem↗
PubMed2003

Forest management is associated with physiological stress in an old-growth forest passerine.

We investigated how physiological stress in an area-sensitive old-growth forest passerine, the Eurasian treecreeper (Certhia familiaris), is associated with forest fragmentation and forest structure. We found evidence that the concentrations of plasma corticosterone in chicks were higher under poor food supply in dense, young forests than in sparse, old forests. In addition, nestlings in large forest patches had lower corticosterone levels and a better body condition than in small forest patches. In general, corticosterone levels were negatively related to body condition and survival. We also found a decrease in corticosterone levels within the breeding season, which may have been a result of an increase in food supply from the first to the second broods. Our results suggest that forest fragmentation may decrease the fitness of free-living individual treecreepers.

Animals↗
PubMed2002

Forests, carbon and global climate.

This review places into context the role that forest ecosystems play in the global carbon cycle, and their potential interactions with climate change. We first examine the natural, preindustrial carbon cycle. Every year forest gross photosynthesis cycles approximately one-twelfth of the atmospheric stock of carbon dioxide, accounting for 50% of terrestrial photosynthesis. This cycling has remained almost constant since the end of the last ice age, but since the Industrial Revolution it has undergone substantial disruption as a result of the injection of 480 PgC into the atmosphere through fossil-fuel combustion and land-use change, including forest clearance. In the second part of this paper we review this 'carbon disruption', and its impact on the oceans, atmosphere and biosphere. Tropical deforestation is resulting in a release of 1.7 PgC yr(-1) into the atmosphere. However, there is also strong evidence for a 'sink' for carbon in natural vegetation (carbon absorption), which can be explained partly by the regrowth of forests on abandoned lands, and partly by a global change factor, the most likely cause being 'fertilization' resulting from the increase in atmospheric CO(2). In the 1990s this biosphere sink was estimated to be sequestering 3.2 PgC yr(-1) and is likely to have substantial effects on the dynamics, structure and biodiversity of all forests. Finally, we examine the potential for forest protection and afforestation to mitigate climate change. An extensive global carbon sequestration programme has the potential to make a particularly significant contribution to controlling the rise in CO2 emissions in the next few decades. In the course of the whole century, however, even the maximum amount of carbon that could be sequestered will be dwarfed by the magnitude of (projected) fossil-fuel emissions. Forest carbon sequestration should only be viewed as a component of a mitigation strategy, not as a substitute for the changes in energy supply, use and technology that will be required if atmospheric CO(2) concentrations are to be stabilized.

Air Pollution↗
PubMed2002

Potential carbon mitigation and income in developing countries from changes in use and management of agricultural and forest lands.

The many opportunities for mitigating atmospheric carbon emissions in developing countries include reforesting degraded lands, implementing sustainable agricultural practices on existing lands and slowing tropical deforestation. This analysis shows that over the next 10 years, 48 major tropical and subtropical developing countries have the potential to reduce the atmospheric carbon burden by about 2.3 billion tonnes of carbon. Given a central price of $10 per tonne of carbon and a discount rate of 3%, this mitigation would generate a net present value of about $16.8 billion collectively for these countries. Achieving these potentials would require a significant global effort, covering more than 50 million hectares of land, to implement carbon-friendly practices in agriculture, forest and previously forested lands. These estimates of host-country income potentials do not consider that outside financial investment may or may not be available. Our calculations take no account of the additional benefits of carbon sequestration in forest soils undergoing reforestation, increased use of biomass and reduced use of fossil-fuel inputs and reduced agricultural emissions. In all events, realizing these incomes would necessitate substantially greater policy support and investment in sustainable land uses than is currently the case.

Africa↗
PubMed2002

Social capital from carbon property: creating equity for indigenous people.

New incentives for protection and in situ use of forests and the services they provide raise hopes for the reversal of tropical and temperate deforestation. Past management of forests appropriated the rights of forest communities, providing incentives to convert natural forest into financial capital through logging, while destroying the underlying physical property. Carbon trading aims to provide a means to convert the forest property into financial capital, while protecting the physical property of forests, thereby providing new incentives for in situ forest management. The potential for carbon-emission trading as a contributor to these new incentives is tempered by concerns that it is another tool for capitalists to exploit the indigenous communities of the developing world. Estimates of annual emission trading amounting to US $200 billion raise alarm bells about the effect of such trade in the developing world. People are right to be concerned, as the history of exploitation of indigenous people, the appropriation of their rights, the loss of forests and their benefits is well documented. This exploitation resulted in the exclusion of forest communities from the basic tenets for development created by the wealth generated by traded property. However, one virtue of trade is that it can be made subject to constraints. Through international treaties and agreements, trade can be constrained and national governments obliged to observe the rules of trade. The value of tradable carbon credits will be discounted or invalid if they do not meet these criteria, providing all parties with strong incentives to achieve the necessary performance standards relating to both processes and contracts. For carbon trading to develop social capital from natural capital requires the admission of forest communities into the polity and management of forest resources. In this paper we argue for responsible carbon-emission trading based on the clear and appropriate definition of carbon entitlements, with the proviso that trading respects the rights and needs of indigenous people. We adopt this position as emissions trading now seems inevitable and there should be proper rules to control this trade where it affects forests and their inhabitants. It is imperative that the poor and indigenous people are not excluded from these systems. Trading systems and the property systems they depend on need to be more accountable, transparent and inclusive of those features which we propose.

Capitalism↗
PubMed2002

Protecting terrestrial ecosystems and the climate through a global carbon market.

Protecting terrestrial ecosystems through international environmental laws requires the development of economic mechanisms that value the Earth's natural systems. The major international treaties to address ecosystem protection lack meaningful binding obligations and the requisite financial instruments to affect large-scale conservation. The Kyoto Protocol's emissions-trading framework creates economic incentives for nations to reduce greenhouse-gas (GHG) emissions cost effectively. Incorporating GHG impacts from land-use activities into this system would create a market for an important ecosystem service provided by forests and agricultural lands: sequestration of atmospheric carbon. This would spur conservation efforts while reducing the 20% of anthropogenic CO(2) emissions produced by land-use change, particularly tropical deforestation. The Kyoto negotiations surrounding land-use activities have been hampered by a lack of robust carbon inventory data. Moreover, the Protocol's provisions agreed to in Kyoto made it difficult to incorporate carbon-sequestering land-use activities into the emissions-trading framework without undermining the atmospheric GHG reductions contemplated in the treaty. Subsequent negotiations since 1997 failed to produce a crediting system that provides meaningful incentives for enhanced carbon sequestration. Notably, credit for reducing rates of tropical deforestation was explicitly excluded from the Protocol. Ultimately, an effective GHG emissions-trading framework will require full carbon accounting for all emissions and sequestration from terrestrial ecosystems. Improved inventory systems and capacity building for developing nations will, therefore, be necessary.

Air Pollution↗
PubMed2002

Species survival and carbon retention in commercially exploited tropical rainforest.

Since deforestation is one of the sources of carbon dioxide increase in the atmosphere, any measures that prevent or reduce the amount of forest removal are beneficial to the environment and to conservation of biodiversity. In recent years, there has been considerable research on the value of standing forests and many researchers have promoted the management of tropical forests as the best type of land use. On the other hand, the enormous diversity is a serious obstacle to management and use of tropical rainforest. A single hectare of forest can have up to 306 species of trees of 10 cm diameter or more. Here we present a brief review of some of the research and programmes that have tried to promote the use and conservation of tropical forest without clear felling. The sustainable use of the standing forest has usually been promoted as a means of species conservation; however, it is also a way to maintain the carbon fixed in the ecosystem. Here we review some of the pros and cons of extraction of non-timber forest products.

Carbon↗
PubMed2003

Ecological impacts of atmospheric CO2 enrichment on terrestrial ecosystems.

Global change has many facets, of which land use and the change of atmospheric chemistry are unquestioned primary agents, which induce a suite of secondary effects, including climatic changes. The largest single contribution to the compositional change of the atmosphere, CO(2) enrichment, has (besides its influence on climate) immediate and direct effects on plants. Quantitatively, CO(2) is the plant 'food' number one, and the rate of photosynthetic CO(2) uptake by leaves is not yet CO(2)-saturated. This abrupt change of the biosphere's diet does and will affect all aspects of life, including our food. However, the plant and ecosystem responses are more subtle than had been assumed from the results of responses of isolated, well-fertilized and well-watered plants in greenhouses during the early days of CO(2)-enrichment research. In this article, I discuss potential responses of complex natural grassland and diverse forests, and address three key themes: CO(2) and nutrients; CO(2) and water; CO(2) and plant-animal interactions. Examples from a suite of climatic regions emphasize that the most important ecosystem level responses to elevated CO(2) will be introduced by differential responses of species. Atmospheric CO(2) enrichment is a biodiversity issue. Classical physiological baseline responses of leaves to elevated CO(2) can be overrun by biodiversity effects to such an extent that some of the traditional predictions may even become reversed. For instance, biodiversity effects may cause humid tropical forests (those which avoid destruction) to become more dynamic and store less, rather than more, carbon as CO(2) enrichment continues. The abundance of certain life forms and species and their lifespans exert major controls over the half-life of carbon stored in forest biomass, and there is evidence that elevated CO(2) can affect these controls and most likely does so already. Also, long-term hydrological consequences of atmospheric CO(2) enrichment will be driven by biodiversity effects, given that some, but not all, species reduce their rate of water loss when exposed to a CO(2)-rich atmosphere. Such insights call for much more realistic experimental conditions and larger-scale test units, which permit biotic interactions across taxa and trophic levels to occur while simulating our CO(2) future. The evidence currently available suggests that ecosystem processes reflect the composition of their biological inventory and this will be affected by a shift in carbon supply.

Animals↗
PubMed1999

Hydrological investigations of forest disturbance and land cover impacts in South-East Asia: a review.

Investigations of land management impacts on hydrology are well developed in South-East Asia, having been greatly extended by national organizations in the last two decades. Regional collaborative efforts, such as the ASEAN-US watershed programme, have helped develop skills and long-running monitoring programmes. Work in different countries is significant for particular aspects: the powerful effects of both cyclones and landsliding in Taiwan, the significance of lahars in Java, of small-scale agriculture in Thailand and plantation establishment in Malaysia. Different aid programmes have contributed specialist knowledge such as British work on reservoir sedimentation, Dutch, Swedish and British work on softwood plantations and US work in hill-tribe agriculture. Much has been achieved through individual university research projects, including PhD and MSc theses. The net result is that for most countries there is now good information on changes in the rainfall-run-off relationship due to forest disturbance or conversion, some information on the impacts on sediment delivery and erosion of hillslopes, but relatively little about the dynamics and magnitude of nutrient losses. Improvements have been made in the ability to model the consequences of forest conversion and of selective logging and exciting prospects exist for the development of better predictions of transfer of water from the hillslopes to the stream channels using techniques such as multilevel modelling. Understanding of the processes involved has advanced through the detailed monitoring made possible at permanent field stations such as that at Danum Valley, Sabah.

Asia, Southeastern↗
PubMed1999

The effects of selective logging on the distribution of moths in a Bornean rainforest.

The effects of selective logging on the diversity and species composition of moths were investigated by sampling from multiple sites in primary forest, both understorey and canopy, and logged forest at Danum Valley, Sabah, Malaysia. The diversity of individual sites was similar, although rarefied species richness of logged forest was 17% lower than for primary forest (understorey and canopy combined). There was significant heterogeneity in faunal composition and measures of similarity (NESS index) among primary forest understorey sites which may be as great as those between primary understorey and logged forest. The lowest similarity values were between primary forest understorey and canopy, indicating a distinct canopy fauna. A number of species encountered in the logged forest were confined to, or more abundant in, the canopy of primary forest. Approximately 10% of species were confined to primary forest across a range of species' abundances, suggesting this is a minimum estimate for the number of species lost following logging. The importance of accounting for heterogeneity within primary forest and sampling in the canopy when measuring the effects of disturbance on tropical forest communities are emphasized.

Animals↗
PubMed1999

Mechanisms of maintenance of tropical freshwater fish communities in the face of disturbance.

Community resistance to, and resilience from, perturbation will determine the trajectory of recovery from disturbance. Although selective timber extraction is considered a severe disturbance, fish communities from headwater streams around Danum Valley Field Centre, Sabah, Malaysia, showed few long-term changes in species composition or abundance. However, some species showed short-term (< 18 months) absence or decrease in abundance. These observations suggested that both resistance and resilience were important in maintaining long-term fish community structure. Resistance to perturbation was tested by monitoring fish communities before and after the creation of log-debris dams, while resilience was investigated by following the time-course of recolonization following complete removal of all fish. High community resistance was generally shown although the response was site-specific, dependent on the composition of the starting community, the size of the stream and physical habitat changes. High resilience was demonstrated in all recolonization experiments with strong correlations between pre- and post-defaunation communities, although there was a significant difference between pool and riffle habitats in the time-course of recovery. These differences can be explained by the movement characteristics of the species found in the different habitats. Resilience appeared to be a more predictable characteristic of the community than resistance and the implications of this for ensuring the long-term persistence of fish in the area are discussed.

Animals↗
PubMed2001

Nitrogen export from a watershed subjected to partial salvage logging.

Logging has been shown to induce nitrogen (N) leaching. We hypothesized that logging a watershed that previously exhibited forest decline symptoms would place additional stress on the ecosystem and result in greater N loss, compared to harvesting vigorous forests. We conducted a 10-year (1988 to 1998) assessment of N export from the Baldwin Creek watershed in southwestern Pennsylvania that was partially clearcut to salvage dead and dying northern red oak. N export from the watershed increased significantly following salvage logging operations and did not completely return to prelogging levels by the end of the study period. The largest annual NO3-N export of 13 kg/ha was observed during the first year after harvesting, an increase of approximately 10 kg/ha. Compared to data from other Appalachian Mountain watersheds in North Carolina, West Virginia, and Pennsylvania, calculated N loss for Baldwin Creek was considerably greater. Longer periods of reduced N uptake due to slow revegetation of salvage logged areas, coupled with increased amounts of N available to leaching, could have accounted for the large N losses observed for Baldwin Creek. Salvage logging of dead and dying trees from forested watersheds in this region appears to have the potential to result in much larger N losses than previously reported for harvest of healthy stands.

Ecosystem↗
PubMed2002

Anthropogenic effects on forest ecosystems at various spatio-temporal scales.

The focus in this review of long-term effects on forest ecosystems is on human impact. As a classification of this differentiated and complex matter, three domains of long-term effects with different scales in space and time are distinguished: Exploitation and conversion history of forests in areas of extended human settlement, Long-range air pollution and acid deposition in industrialized regions, Current global loss of forests and soil degradation. There is an evident link between the first and the third point in the list. Cultivation of primary forestland--with its tremendous effects on land cover--took place in Europe many centuries ago and continued for centuries. Deforestation today is a phenomenon predominantly observed in the developing countries, yet it threatens biotic and soil resources on a global scale. Acidification of forest soils caused by long-range air pollution from anthropogenic emission sources is a regional to continental problem in industrialized parts of the world. As a result of emission reduction legislation, atmospheric acid deposition is currently on the retreat in the richer industrialized regions (e.g., Europe, U.S., Japan); however, because many other regions of the world are at present rapidly developing their polluting industries (e.g., China and India), "acid rain" will most probably remain a serious ecological problem on regional scales. It is believed to have caused considerable destabilization of forest ecosystems, adding to the strong structural and biogeochemical impacts resulting from exploitation history. Deforestation and soil degradation cause the most pressing ecological problems for the time being, at least on the global scale. In many of those regions where loss of forests and soils is now high, it may be extremely difficult or impossible to restore forest ecosystems and soil productivity. Moreover, the driving forces, which are predominantly of a demographic and socioeconomic nature, do not yet seem to be lessening in strength. It can only be hoped that a wise policy of international cooperation and shared aims can cope with this problem in the future.

Acid Rain↗