SEARCH · Search PubMed

Results for “Deforestation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed2005

Selective logging in the Brazilian Amazon.

Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square kilometers per year (+/-14%) between 1999 and 2002, equivalent to 60 to 123% of previously reported deforestation area. Up to 1200 square kilometers per year of logging were observed on conservation lands. Each year, 27 million to 50 million cubic meters of wood were extracted, and a gross flux of approximately 0.1 billion metric tons of carbon was destined for release to the atmosphere by logging.

Brazil↗

PubMed2000

Economic incentives for rain forest conservation across scales.

Globally, tropical deforestation releases 20 to 30% of anthropogenic greenhouse gases. Conserving forests could reduce emissions, but the cost-effectiveness of this mechanism for mitigation depends on the associated opportunity costs. We estimated these costs from local, national, and global perspectives using a case study from Madagascar. Conservation generated significant benefits over logging and agriculture locally and globally. Nationally, however, financial benefits from industrial logging were larger than conservation benefits. Such differing economic signals across scales may exacerbate tropical deforestation. The Kyoto Protocol could potentially overcome this obstacle to conservation by creating markets for protection of tropical forests to mitigate climate change.

Agriculture↗

PubMed2026

Protecting tropical forests is more cost-effective for biodiversity and climate than restoration.

Halting deforestation and promoting restoration are at the core of strategies to confront the biodiversity and climate crises in tropical forests. Avoiding forest disturbances is also critically important but has received far less attention, and there is a lack of clarity about the relative cost-effectiveness of these three interventions. We compare the biodiversity and carbon benefits and costs associated with each intervention, comparing observed and counterfactual outcomes based on in-depth field assessments and high-resolution remote sensing in the Brazilian Amazon deforestation frontier. Avoidance interventions delivered the greatest benefits and were more cost-effective than restoration, with results being robust to a range of benefit and cost assumptions. However, combined interventions delivered the greatest gains and were essential to reverse biodiversity and carbon losses.

Biodiversity↗

PubMed2006

Genetic signature of anthropogenic population collapse in orang-utans.

Great ape populations are undergoing a dramatic decline, which is predicted to result in their extinction in the wild from entire regions in the near future. Recent findings have particularly focused on African apes, and have implicated multiple factors contributing to this decline, such as deforestation, hunting, and disease. Less well-publicised, but equally dramatic, has been the decline in orang-utans, whose distribution is limited to parts of Sumatra and Borneo. Using the largest-ever genetic sample from wild orang-utan populations, we show strong evidence for a recent demographic collapse in North Eastern Borneo and demonstrate that this signature is independent of the mutation and demographic models used. This is the first demonstration that genetic data can detect and quantify the effect of recent, human-induced deforestation and habitat fragmentation on an endangered species. Because current demographic collapses are usually confounded by ancient events, this suggests a much more dramatic decline than demographic data alone and emphasises the need for major conservation efforts.

Animals↗

PubMed1999

Chagas disease: from bush to huts and houses. Is it the case of the Brazilian Amazon?

Two of the major problems facing the Amazon - human migration from the other areas and uncontrolled deforestation - constitute the greatest risk for the establishment of endemic Chagas disease in this part of Brazil. At least 18 species of triatomines had been found in the Brazilian Amazon, 10 of them infected with Trypanosoma cruzi, associated with numerous wild reservoirs. With wide-range deforestation, wild animals will perforce be driven into other areas, with tendency for triatomines to become adapted to alternative food sources in peri and intradomicilies. Serological surveys and cross-sectional studies for Chagas disease, carried out in rural areas of the Rio Negro, in the Brazilian Amazon, showed a high level of seropositivity for T. cruzi antibodies. A strong correlation of seroreactivity with the contact of gatherers of piaçava fibers with wild triatomines could be evidenced.

Adolescent↗

PubMed2001

[Tegumentary leishmaniasis in area with epidemic levels of transmission, Salta, Argentina, 1998].

The incidence of tegumentary leishmaniasis increased in October 1997, in an area close to Oran city, province of Salta. The leishmaniasis' epidemiology and the entomology of this outbreak were studied during June 1998 at Paraje Las Carmelitas and Río Blanco, places with high reported incidence. The prevalence of infection (Montenegro Skin Test reactive) was 171/1000 inhabitants in Paraje Las Carmelitas and 790/1000 in Río Blanco, while the rates of leishmaniasis' incidence (active ulcers) were 72/1000 and 790/1000. The prevalence differences among sex and age groups were not significant. The clinical and epidemiologic patterns were consistent with those reported in the area for Leishmania (Viannia) braziliensis. Lutzomyia intermedia was the prevalent species (96%) among 2577 Phlebotominae collected, Lu. shannoni, Lu. cortelezzii y Lu. migonei were also present. The results about distribution of prevalence by age, and spatial distribution of Phlebotominae supported deforestation-residual primary forest transmission hypotheses. Therefore, in Salta the epidemic outbreaks generated by extensive deforestation could be sustained and amplified because the human settlements are located close to the remaining primary forest "spots". Furthermore, in this scenario the risk of human-vector contact increases by the subsistence or recreational activities performed in secondary transitional forests, and the presence of domestic animals around the houses. The results are discussed in the frame of possible control strategies.

Adolescent↗

PubMed2002

Environmental, health and economic conditions perceived by 50 rural communities in Bangladesh.

For randomly selected 50 villages in Bangladesh, an interview survey with a structured questionnaire was conducted to reveal their perception on the environmental, health and economic conditions at present and for the past 10-year change. The eight following items were analyzed in this paper: air pollution and water pollution, which represent environmental conditions with close relation to health conditions, soil degradation and deforestation, which represent environmental conditions with close relation to economic conditions, epidemic diseases and malnutrition, which represent health conditions, and poverty and jobless, which represent economic conditions. Among the 50 villages, deforestation was most frequently perceived serious at present and worsened in the past 10 years. Of the remaining seven items, those related to economic conditions were more seriously perceived than those related to health and environmental conditions. As revealed by the cluster analysis for the inter-item relations, epidemic diseases, which formed the same cluster with the environmental items, were recognized less serious whereas malnutrition, which formed the same cluster with the economic items, was recognized more serious. These findings are useful not only for rural development programs but also for mitigation programs toward health and environmental hazards in Bangladesh.

Bangladesh↗

PubMedDate not supplied

Use of the ecosystem approach to population health: the case of mercury contamination in aquatic environments and riparian populations, Andean Amazon, Napo River Valley, Ecuador.

BACKGROUND: Driven by accelerating transformation of land use in the Amazon, studies addressing the impacts of deforestation and mercury (Hg) leaching on the geophysical, biological, social, health, economic and political systems of Amazonian countries are crucial to evaluate the population health risks of these rapid changes. METHODS: We used an ecosystem approach, integrating Hg measurements with socio-cultural and politico-economic elements, to provide an integral analysis and comprehensive solutions. RESULTS: Our interdisciplinary research in the Ecuadorian Andean Amazon has shown that comestible fish and riparian communities which rely on fish as a major protein source have mercury levels that could potentially cause subtle but deleterious population health alterations. A parallel study identified deforestation and soil erosion as a significant source of mercury to the aquatic ecosystem. INTERPRETATION: The analysis of these results in conjunction with the prevailing socio-cultural and politico-economic context allowed us to identify economic trends, and especially petroleum exploitation, as pivotal in the deforestation/mercury-exposure dynamic. In collaboration with public health authorities, we shared our results with local health stakeholders, including public health care staff, federal government agencies, researchers and local communities, in such a way as to promote sustainable land use practices and the nutritional benefits of fish eating while reducing toxic exposures.

Animals↗

PubMed2005

Soybean production and conversion of tropical forest in the Brazilian Amazon: the case of Vilhena, Rondônia.

The recent rise in Brazilian soybean production has generated concern among the environmental community and some authors that natural tropical environments of the Amazon Basin are being converted to soybean fields. Proponents of soybean production counter that soybeans represent a viable agricultural commodity for the region; environmental concern is unwarranted, because new soybean fields are replacing already deforested or otherwise transformed lands. Both arguments have been made without comprehensive study and measure of land-use/land-cover (LULC) in areas undergoing expansion of soybean production. This case study, conducted in the municipality of Vilhena, Rondônia, Brazil, in the southwestern Amazon Basin, uses remote sensing to evaluate the LULC accompanying this municipality's large growth in soybean production from 1996 to 2001. Forests are being converted for soybean production, but most of the production increase appears attributable to slight expansion of already existing fields, conversion of already deforested land, and higher yields.

Brazil↗

PubMed2005

Natural recharge to sustainable yield from the barind aquifer: a tool in preparing effective management plan of groundwater resources.

This paper presents the results of water balance study and aquifer simulation modeling for preliminary estimation of the recharge rate and sustainable yield for the semi arid Barind Tract region of Bangladesh. The outcomes of the study are likely to be useful for planning purposes. It is found from detailed water balance study for the area that natural recharge rates in the Barind Tract vary widely year to year. It may have resulted from the method used for the calculation. If the considered time interval had been smaller than the monthly rainfall, the results could have been different. Aquifer Simulation Modeling (ASM) for the Barind aquifer is used to estimate long-term sustainable yield of the groundwater considering limiting drawdown from the standpoint of economic pumping cost. In managing a groundwater basin efficiently and effectively, evaluation of the maximum annual groundwater yield of the basin that can be withdrawn and used without producing any undesirable effect is one of the most important issues. In investigating such recharge rate, introduction of certain terms such as sustainable yield and safe yield has been accompanied. Development of this area involves proper utilization of this vast land, which is possible only through ensured irrigation for agriculture. The Government of Bangladesh has a plan to develop irrigation facilities by optimum utilization of available ground and surface water. It is believed that the groundwater table is lowering rapidly and the whole region is in an acute state of deforestation. Indiscriminate groundwater development may accelerate deforestation trend. In this context estimation of actual natural recharge rate to the aquifer and determination of sustainable yield will assist in proper management and planning of environmentally viable abstraction schemes. It is revealed from the study that the sustainable yield of ground water (204 mm/y) is somewhat higher than the long-term annual average recharge (152.7 mm) to the groundwater reservoir. The reason behind this is that the rivers within and around the Barind Tract might have played the role of influent rivers.

Agriculture↗

PubMed2005

For holistic control of reactive N: regional, national and global perspectives.

Reactive N is closely related to the global issues of climate change and regional pollutions. Nitrous oxide (N20), the fourth important gas among greenhouse gases, is produced as an intermediate in nitrification and denitrification processes. As methane (CH4) is the end product in the anoxic decomposition of organic materials, mitigation options of N20 emission are different from those of CH4 emission. Nitrate is another reactive N bringing about the eutrification of aqueous environments and the hazard of drinking water. Mitigation of NO3 problem also relates closely to the N20 emission. Therefore, holistic approaches are necessary for solving the problems of Earth warming and environmental eutrification by reactive N at the same time. In this paper, the deforestation in the tropics, and the present situations of food supply and sustainable agriculture in Japan are re-evaluated in terms of N20 emission and NO3 discharge from the agricultural sector. The magnitude of N20 emission by deforestation in the tropics may fall within the similar order of magnitude by N fertilization. As more N is imported as foods and fodder than the amount of fertilized N in Japan, more attention should be paid to the phases of their consumption and waste treatment. Sole attention to the production stage is not enough for the total mitigation of various environmental problems by reactive N in relation to agriculture. Parameters holistically evaluating the impact of reactive N on the Earth and respective regions are urgently necessary.

Agriculture↗

PubMed1994

[Leishmaniasis in Ecuador. 5. Leishmaniasis and anthropization on the Pacific coast].

We have evaluated the impact of anthropization of the forest on the incidence of leishmaniasis, due to Leishmania panamensis, in three coastal study areas, Corriente Grande (primary forest), Paraiso Escondido and La Tablada (secondary forest). The situation of isolated dwellings, in deforested areas, has also been analysed in the last two stations. In each station, the study of the density of anthropophilic sand flies, specially Lutzomyia trapidoi, has been conducted in the domestic environment, coffee plantations and undergrowth. The incidence of leishmaniasis was nearly non existent in primary forest, though it ranged from 106 to 147% in the more or less cleared forest. At Corriente Grande, none Lu. trapidoi was caught in houses. In the undergrowth, catches were low (8% of the total). At Paraiso Escondido, Lu. trapidoi was the dominant species, with more than 83% of the catches in the undergrowth and in the coffee plantations (41 Man/hour), as well as in dwellings (10.6 M/h). At La Tablada, in the domestic environment, Lu. gomezi, was the dominant species: 2.8 M/h against 0.1 M/h for Lu. trapidoi. In the coffee plantations and in the undergrowth Lu. trapidoi was the main species, 21 M/h and 14 M/h. Thus in the primary rainforest, leishmaniasis transmission can be very low. In disturbed forest, coffee plantations near houses are good biotopes for Lu. trapidoi. The cycle of L. panamensis has been adapted to this new ecological situation, by being closer to the houses. The reservoirs live and circulate throughout coffee plantations. In deforested areas, neither aggressive sand flies have been observed, nor leishmaniasis transmission.

Animals↗

PubMed1996

[Population and underdevelopment--thoughts on the Cairo International Conference on Population and Development].

The continuing rapid growth of world population, particularly in the developing countries, is described. "The backward social and economic environment is not able to keep pace with the growing population. The result is an increasing population pressure which finds its expression in unemployment, hunger, the depletion of...nature, deforestation as well as migration, uncontrolled expansion of the cities and slum-building. These problems [already have] global dimensions and their aggravation is expected in the next 30 years. Our civilisation is exposed to these global risks. And we have no practicable conception for solving them." (SUMMARY IN ENG)

Conservation of Natural Resources↗

PubMed2005

Demography, range use, and behavior in black lemurs (Eulemur macaco macaco) at Ampasikely, northwest Madagascar.

We studied a black lemur population over a 2-year period (1992-1993) and 8 years later (2000) in a 50-ha secondary forest in northwest Madagascar. All of the animals were marked to investigate population dynamics and seasonal variation in ranging and behavior, and new data on black lemurs were obtained. Our data on demographic characteristics were expanded to include other forest sites and contrasted with those collected in other Eulemur macaco macaco field studies, in relation to human activity and the presence of introduced and cultivated plant species. Density is affected by deforestation and hunting. Group size and home range depend on the composition of the forest and probably food patches. Sex ratio at birth varies according to the number of females per group, a result that fits the local resource competition model. Groups are multimale-multifemale, and adult females form the core of the groups. Reproductive parameters indicate sharply defined seasonal breeding, a high female reproductive rate, and birth synchrony. Changes in group composition reveal male and female juvenile dispersal, male transfer between groups at the time of mating, and adult female transfer and group fission when groups exceed a critical size. At mating and birth, intergroup agonistic encounters occurred at home-range boundaries, and larger groups were dominant over smaller groups. Patterns of intragroup interactions suggest that males compete for access to groups of females during the mating season, and that females may compete for food resources during the birth season. Our study also reports female social dominance and lack of sexual weight dimorphism in this species.

Animals↗

PubMed2004

Demographic parameters and life history of chimpanzees at Bossou, Guinea.

Demographic parameters of wild chimpanzees at Bossou, Guinea, are presented and compared with those of other populations. The population size of Bossou chimpanzees has been stable over the last 26 years, except during two incidents of partial deforestation. The annual birth rate for a female (mean = 0.194, but 0.165 when the infant survived more than 4 years) and interbirth interval are not much different from those of other study sites. The primiparous age of Bossou chimpanzees, however, is far younger (mean = 10.9 years) than for all other known wild chimpanzee populations. The infant and juvenile survival rate is also the highest (female = 0.64, male = 0.52 for the first 8 years). As a result, the lifetime reproductive success of Bossou chimpanzees is estimated to be highest among long-term study sites. The rate of disappearance from Bossou dramatically increases during the adolescent stage, and most young chimpanzees disappear before or around maturation. Probably because the environmental capacity for chimpanzees at Bossou is at its limit, many young independent males, as well as females, have to disperse, though others may die. For chimpanzee alpha males of other populations, mature males may be needed as collaborators to defend resources. In the case of Bossou, however, a lack of adjacent groups, conspecific competitors, predators, and perhaps medium-sized mammals as prey for group hunting may eliminate this need of the alpha male for other males. The reasons why all males of other chimpanzee populations persist in being philopatric for life and maintain kin-related male bonds differing from most mammal species, including humans, are discussed.

Animals↗

PubMed2004

Mercury hazards from gold mining to humans, plants, and animals.

Mercury contamination of the environment from historical and ongoing mining practices that rely on mercury amalgamation for gold extraction is widespread. Contamination was particularly severe in the immediate vicinity of gold extraction and refining operations; however, mercury, especially in the form of water-soluble methylmercury, may be transported to pristine areas by rainwater, water currents, deforestation, volatilization, and other vectors. Examples of gold mining-associated mercury pollution have been shown for Canada, the U.S., Africa, China, the Philippines, Siberia, and South America. In parts of Brazil, for example, mercury concentrations in all abiotic materials, plants, and animals, including endangered species of mammals and reptiles, collected near ongoing mercury amalgamation gold mining sites were far in excess of allowable mercury levels promulgated by regulatory agencies for the protection of human health and natural resources. Although health authorities in Brazil are unable to detect conclusive evidence of human mercury intoxication, the potential exists in the absence of mitigation for epidemic mercury poisoning of the mining population and environs. In the U.S., environmental mercury contamination is mostly from historical gold mining practices, and portions of Nevada remain sufficiently mercury contaminated to pose a hazard to reproduction of carnivorous fishes and fish-eating birds. Concentrations of total mercury lethal to sensitive representative natural resources range from 0.1 to 2.0 microg/L of medium for aquatic organisms; from 2,200 to 31,000 microg/kg BW (acute oral) and from 4,000 to 40,000 microg/kg (dietary) for birds; and from 100 to 500 microg/kg BW (daily dose) and from 1,000 to 5,000 microg/kg diet for mammals. Significant adverse sublethal effects were observed among selected aquatic species at water concentrations of 0.03-0.1 microg Hg/L. For some birds, adverse effects, mainly on reproduction, have been associated with total mercury concentrations (microg/kg FW) of 5,000 in feathers, 900 in eggs, and 50-100 in diet, and with daily intakes of 640 microg/kg BW. Sensitive nonhuman mammals showed significant adverse effects of mercury when daily intakes were 250 microg/kg BW, when dietary levels were 1,100 microg/kg, or when tissue concentrations exceeded 1,100 microg/kg. Proposed mercury criteria for protection of aquatic life range from 0.012 microg/L for freshwater life to 0.025 microg/L for marine life; for birds, less than 100 microg/kg diet FW; and for small mammals, less than 1,100 microg/kg FW diet. All these proposed criteria provide, at best, minimal protection.

Animals↗

PubMed1996

Joint Implementation: Biodiversity and Greenhouse Gas Offsets

/ One of the most pressing environmental issues today is the possibility that projected increases in global emissions of greenhouse gases from increased deforestation, development, and fossil-fuel combustion could significantly alter global climate patterns. Under the terms of the United Nations Framework Convention on Climate Change, signed in Rio de Janeiro during the June 1992 Earth Summit, the United States and other industrialized countries committed to balancing greenhouse gas emissions at 1990 levels in the year 2000. Included in the treaty is a provision titled "Joint Implementation," whereby industrialized countries assist developing countries in jointly modifying long-term emission trends, either through emission reductions or by protecting and enhancing greenhouse gas sinks (carbon sequestration). The US Climate Action Plan, signed by President Clinton in 1993, calls for voluntary climate change mitigation measures by various sectors, and the action plan included a new program, the US Initiative on Joint Implementation. Wisconsin Electric decided to invest in a JI project because its concept encourages creative, cost-effective solutions to environmental problems through partnering, international cooperation, and innovation. The project chosen, a forest preservation and management effort in Belize, will sequester more than five million tons of carbon dioxide over a 40-year period, will become economically self-sustaining after ten years, and will have substantial biodiversity benefits.KEY WORDS: Joint implementation; Activities implemented jointly; Carbon sequestration; Carbon dioxide; Global climate change; Greenhouse gas; Belize

Journal Article↗

PubMed1996

Decreased Carbon and Nutrient Input to Boreal Lakes from Particulate Organic Matter Following Riparian Clear-Cutting

The plankton communities of oligotrophic Canadian Shield lakes are strongly regulated by the allochthonous supply of total phosphorus (TP) and dissolved organic carbon (DOC), a proportion of both of which originate from particulate organic matter. Although decreased inputs of allochthonous leaf litter have been documented for small streams whose riparian forests have been removed, no such data exist for boreal lakes. Through estimates of airborne litter input from forested and clear-cut shorelines and laboratory measurements of concentrations released from leaf leachate, we determined that riparian deforestation resulted in reductions of DOC from 17.8 to 0.4 g/m shoreline/yr and of TP from 2.9 to 0.3 g/m shoreline/yr. Previous predictive models indicate that such reductions may be substantial enough to decrease basic metabolic processes of lake plankton communities by as much as 9% in primary production and 17% in respiration.

Journal Article↗