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PubMed2003

[Ecological risk assessment of forest resource in northeast China].

Based on the theory and methods of regional eco-risk assessment (REA), the eco-risk of forest resources in northeast China is evaluated. The stresses resulting in the eco-risk of forest resources are physical, chemical, biological and social stresses. The weighed coefficient is 0.30, 0.22, 0.11 and 0.37, respectively. In 93 forest bureaus of this area, 64.4% bureaus are in slight risk, 21.2% in mid-risk, 13.3% in high risk and 1.1% in very high risk. This is in corresponding with the skew normal distribution. The eco-risk of forest resources in northeast China is closely related to the locality of the resources. The risk becomes more and more serious from east to west. The risk management and restoration of the forest resource must be strengthened.

Conservation of Natural Resources↗
PubMed2003

[Approaches for assessing forest ecosystem health].

Assessment and indicator system become the key issues in the research on ecosystem health in 21st century. Assessing forest ecosystem health gradually attach much attention because it is an important component of terrestrial ecosystem. The definition, measurement, evaluation and its management had been discussed broadly, and some theories, assessing methods and frameworks had been proposed, which provides a new concept and a serial research approaches for dealing with the crisis of terrestrial ecosystems, even the environment problems in the world. Now, the common operational models for assessing forest ecosystem health do not exist owing to the manifold limitations. This paper discussed forest ecosystem health problem, and brought forward three preconditions for assessing forest ecosystem health: 1) a clear conceptual framework; 2) adequate data sets; 3) proper research and analysis techniques. The issues of three preconditions were discussed, and the possible approaches for the assessing research on forest ecosystem health, e.g., long-term studies and environment monitoring, space-for-time substation studies, e.g., history approaches, economics valuation and others were expariated.

Ecosystem↗
PubMed2003

[Application of mist net in studies of forest bird communities].

It had been more than twenty years for using mist net to study forest avian community. Mist net was very useful for studying cryptic, less vocal or non-vocal, and non-territorial birds, particularly understory birds in forest. The accuracy of mist net was relatively independent of observer biases and skills. It allowed identical and simultaneous sampling of numerous sites and straightforward comparisons among studies done at different sites by different people. So, a lot of ornithologists considered it as a necessary way for studying forest bird communities. Few studies had been reported on bird communities by using mist nets in China. In this paper, some examples on studying forest bird community by using mist nets were introduced, and studies on forest bird community with mist net should be used widely in China in the future.

Animals↗
PubMed2003

[Structure and ecological benefits of urban forest in Shenyang build-up area].

Investigations were made in the sampling plots covering 243 km2 of the Shenyang urban area, and the results were used as the input for the Urban Forest Management Information System (UFMIS), which was developed based on the model of CITY green. With this system, and using tree species, tree density, tree height grade distribution, tree DBH (diameter at beast height) grade distribution, and tree health condition as parameters, the land use and forest structure in Shenyang City were analyzed. It was found that there were 1,914,500 trees in Shenyang, belonging to 136 species. The 25 dominant species accounted for 84.78% of the total number of trees, and the forest coverage was 9.765%. Trees with DBH < 0.25 m and > 0.5 m accounted for 82.8% of the total, and the young, middle-aged and old trees occupied 27%, 58% and 15% of the total, respectively. The healthy status of 84% of the trees was above middle level. Therefore, the forest in Shenyang urban is at a stable stage. According to the statistical results from UFMIS, the ecological value of forest in Shenyang urban is as high as 26,526,955. 1 USD in terms of economy.

China↗
PubMed1992

Ocular onchocerciasis and the intensity of infection in the community. IV. The degraded forest of Sierra Leone.

To assess the pattern of onchocercal ocular disease and blindness in south Sierra Leone, ophthalmological surveys were carried out in 13 highly infected villages located in various river basins. The most important finding was the blinding potential of onchocerciasis in the degraded forest area where the prevalence of onchocercal blindness reached levels of up to 6%. This is remarkable since previous studies have claimed onchocerciasis in the forest to cause little blindness. Ocular onchocerciasis undoubtedly constitutes a problem of public health importance in south Sierra Leone. The rates of onchocercal ocular disease and blindness, however, were significantly lower than those found in savanna villages with similar levels of endemicity. The community pattern of ocular onchocerciasis was not significantly different from the classical pattern in the forest but this could be explained by the low endemicity levels in the forest villages studied. It is therefore not possible to deduce from this study whether the pattern of ocular onchocerciasis in south Sierra Leone is of the forest type, or a pattern on its own.

Adolescent↗
PubMedDate not supplied

[Seasonal dynamics of atmospheric methane oxidation in gray forest soils].

Seasonal fluctuations in the methane flow in the soil-atmosphere system were determined for gray forest soils of Central Russia. Consumption of atmospheric methane was found to exceed methane emission in gray forest soils under forest and in agrocenosis. The average annual rates of atmospheric methane consumption by the soil under forest and in agrocenosis were 0.026 and 0.008 mg CH4-C/(m2 h), respectively. The annual rate of atmospheric methane oxidation in the gray forest soils of Moscow oblast was estimated to be 0.68 kton. Seasonal fluctuations in the methane oxidation activity were due to changes in the hydrothermal conditions and in the reserves of readily decomposable organic matter and mineral nitrogen, as well as to changes in the activity of methane oxidizers.

Air↗
PubMed2004

[Radiation characteristics in a tropical seasonal rain forest canopy gap].

Based on the observations in the radiation with different wavelengths in tropical seasonal rain forest canopy gap, interior of forest, and meteorological station in different seasons, the radiation characteristics of canopy gap were discussed. The results showed that the value of different wavelength radiation had the phenomenon of "suddenly emergent" at the center and north edge of canopy gap. Moreover, each radiation value reached the maximum rapidly, and then decreased quickly around the noon. The daily gross radiation of different wavelengths within the canopy gap was bigger than that in the interior of forest, but smaller than that at meteorological station. Compared to the north edge, the daily gross radiation in the center of the gap was bigger in dry-hot season, rain season and later rain season, but smaller in fog-cool season, which was influenced by dense fog, solar angle and azimuth. The total daily gross solar radiation at the center was the maximum when the solar angle was the biggest in rain season, higher in later rain season and dry-hot season, and was the minimum in fog-cool season. The ratios of infrared and visible light radiation to total solar radiation varied with the seasons at the center and north edge of the canopy gap, which fully indicated the environmental heterogeneity within the canopy gap. Compared with meteorological station and interior of forest, the ratios of infrared radiation to total solar radiation in the gap were bigger than those of meteorological station, but smaller than those of interior of forest, which were just contrary to the ratios of visible light to total solar radiation. In addition, the seasonal variation of the ratios of visible light to total solar radiation was higher than that of the ratios of infrared radiation to total solar radiation within the gap. Generally, canopy gap could increase infrared radiation and decrease visible light radiation in tropical seasonal rainforest.

Environment↗
PubMed2004

Quantitative measurement of spatial forest patterns in Flanders.

Worldwide, scientists and policy-makers emphasize the importance of planning and managing forests for multiple goals. Forests are considered as one of the elements of a landscape. When forests are to be managed at a landscape scale, there is a need for methodologies that describe these forested landscapes quantitatively. In the field of landscape ecology, a comprehensive list of descriptive variables is available for this aim. The selection of relevant variables is therefore important. This paper analyses the forest cover pattern of Flanders. Using multivariate techniques, a set of variables is selected.

Belgium↗
PubMed2004

[Structure characteristics and health distance assessment of various disturbed communities of Korean pine and broadleaved mixed forest in Changbai Mountains].

Through samples investigation, this paper analyzed and classified the community structures of overcutting original forests, secondary birch forests and larch plantation forest under different disturbances. At the same time, some indexes which can reflect the integrity and stability of stand structure were selected. Health Distance (HD) method, a new idea, was attempted to assess ecosystem health of Korean pine and broadleaved mixed forest in Changbai Mountains. The results showed that the health degree was in order of original broadleaved stand (0.14) < structure switched stand (0.23) < structure reserved stand (0.32) < structure destroyed stand (0.33) < heavy disturbed stand (0. 44) < secondary birch stand (0.53) < larch plantations (0.68). Hopefully, it will be a helpful reference on the restoration of Korean pine and broadleaved mixed forest and on the regional forestry sustainable development.

China↗
PubMed2004

[A preliminary study on wood-inhabiting fungi on charred wood in Daxinganling forest areas].

Study on wood-inhabiting fungi is one of the active fields of mycology during past 30 years in China, and the study mostly focused on natural forest without fire disturbing. Forest fire changes forest ecology dramatically, and the fungi on charred wood are different from those in nature forests without fires. In this paper, we focused on the wood-inhabiting fungi growing on charred wood in Daxinganling forest areas. Seventeen species were reported: Antrodia sp., Antrodia rantha, Ceriporiopsis mucida, Diplomitoporus lindbladii, Gloeophyllum carbonarium, Gloeophyllum sepiarium, Gloeoporus taricola, Laurilia sulcata, Oligoporus sericeomollis, Phellinus igniarius, Postia caesia, Postia leucomallella, Postia tephroleuca, Schizopora flavipora, Skeletocutis ochroalba, Skeletocutis vulgaris, and Trichaptum fuscoviolaceum. Among them, eight species caused brown rot, and nine species caused white rot. Based on our field studies, eight species were pioneer fungi in charred wood, four species were common one, and three species were rare or threatened in the studied area. Setting up nature reserve should be the best way to protect the rare or threatened species of wood-inhabiting fungi.

China↗
PubMedDate not supplied

[Physicochemical and biological factors affecting atmospheric methane oxidation in gray forest soils].

The decline of methane oxidizing activities in gray forest soil upon its conversion into arable land was shown to be caused by major changes in biotic and physicochemical properties of soil. Using the method of immune serums, methane-oxidizing bacteria were detected in both forest and agricultural soils, but their populations differed significantly in both abundance and composition. In the forest soil, the number of methanotrophs was an order of magnitude higher than in arable soil, amounting to 3.5 x 10(8) and 0.24 x 10(8) cells/g soil, respectively. All methane-oxidizing bacteria identified in the forest soil belonged to the genus Methylocystis, and 94% of these were represented by a single species, M. parvus. The arable soil was dominated by type I methanotrophs (Methylobacter and Methylomonas, 67.6%), occurring along with bacteria of the genus Methylocystis. In addition, arable soil is characterized by a low content of microbial biomass, lower porosity and water permeability of soil aggregates, and the predominance of nitrogen mineralization processes over those of nitrogen immobilization. These factors can also contribute to lower rates of methane oxidation in arable soil as compared to forest soil.

Agriculture↗
PubMed2005

[Spatial heterogeneity of soil moisture after raining at forest-grassland landscape boundary in hilly area of Loess Plateau].

Soil moisture is a main factor limiting vegetation restoration in semi-arid region. In this paper, the spatial variability of different layers soil moisture after raining at the forest-grassland boundary in hilly area of Loess Plateau were studied by traditional and geostatistical analysis methods. The results showed that the moisture content in surface (0 - 10 cm) and subsurface soil layer (10 - 20 cm) of grassland was higher than that of forestland. The two layers soil moisture content at forest-grassland boundary showed a small variation but an obvious ecological distribution. By using moving split-window techniques, it was obtained that the width of edge influence in surface and subsurface layer was 8 and 6 m, respectively. Geostatistical analyses showed that the spatial distribution of two layers soil moisture had a pure nugget effect in grassland, linear model in forestland, and spherical model in forest-grassland boundary. The spatial heterogeneity of two layers soil moisture was higher at forest-grassland boundary than at forestland and grassland, which had a stronger spatial dependence and autorelation. Kriging maps expressed the spatial structural characters. The distribution of soil moisture in two layers showed a strip shape near forest edge, and a patch shape far from the edge.

China↗
PubMedDate not supplied

Population health effects of air quality changes due to forest fires in British Columbia in 2003: estimates from physician-visit billing data.

BACKGROUND: Major forest fires near populated areas during 2003 exacted a huge economic toll on communities in British Columbia. We designed a study to examine associations between PM2.5 and PM10 levels and physician visits in two affected communities. METHODS: Measurements of 24-hour averages of particulate matter (PM10 and PM2.5) obtained from the monitoring network of the BC Ministry of Water, Land and Air Protection were used to define weeks where forest fires resulted in increases in ambient PM. Weekly rates of physician visits for respiratory (ICD-9 codes 460-519), cardiovascular (390-459) and mental illnesses (290-319) obtained through the Medical Services Plan of BC, were compared for 2003 and aggregates of the 10 previous years. RESULTS: Both the Kelowna and Kamloops regions experienced five weeks of elevated 24-hour average PM levels, although maximum levels in Kelowna were greater. In the Kelowna region, increases in physician visits for respiratory diseases of between 46 and 78% above 10-year mean rates were observed for three weeks during the forest fire period. Similar effects were not observed in Kamloops. Effects on visits for cardiovascular diseases or mental disorders were not seen in either community. INTERPRETATION: Forest fire smoke was associated with an excess of respiratory complaints in Kelowna area residents. The lack of a similar effect in Kamloops is likely due to the population being exposed to lower levels of PM. The absence of apparent cardiovascular health effects may be due to selective effects of forest fire smoke on respiratory tract disease.

Air Pollution↗
PubMed2005

Armillaria mellea as a cause of oak decline in Hatam-baigh forest of Iran.

A200 ha forest of "Hatam-baig" is located in Ardebil Province on the Northwest of Iran. Oak trees (Quercus macranthera Fisch & Mey) in this forest have been faced with declining and extinction since 1991, that has destructed about one third of the forest trees until now. This disorder was expressed in various symptoms including wilting, defoliation and decline. In order to identify factors causing decline, a study was managed from 1998 to 2001. Samples were taken from roots, trunks, crowns and soil beneath the canopy and were cultured on different culture media subsequently. Armillaria mellea (Vahl) P. Kumm., Phytophthora cryptogea Pethybr. & Laff., Dematophora sp., Pythium aphanidermatum (Edson) Fitzp. and Fusarium spp. were the most common isolated fungi. A. mellea appeared to be the essential causal agent of the decline according to the studies made on oak tress decline around the world and based on brown rot observed beneath mycelial fans in the cross section prepared from the trunk and characteristics of the isolated fungi. The fungus activity had been favored by physiological weakness and stresses in oak rootstocks caused by brown- tail moth (Euproctis chrysorhoea L.) and drought stress in infected trees. The biological species of this fungus was identified as Armillaria mellea, using hybridization tests and application of haploid test strains. The fungi such as Phytophthora sp., Pythium sp., and Dematophora sp. can not be infective in this forest due to being hydrophylous. In the southern part of the forest with remarked steepness, the severity of the decline appears to be more than that in the smoothly northern part. The decline of Q. macranthera is reported as matrix nova. The report of the isolated fungi from this oak species is also universally new.

Basidiomycota↗
PubMed2006

[Effects of forest and swamp on hydrochemical characteristics of streams].

With the upper reaches of Gongbiela River in the northeast part of Xiaoxing' an Mountains as test area, this paper studied the hydrochemical characteristics of the streams in forest and swamp during the period of June - September 2004. The results indicated that the hydrochemistry of forest and swamp streams belonged to calcium-bicarbonate type I (C1(Ca)). The pH value, mineralization rate, total hardness, and HCO3(-), SO4(2-), Ca(2+), Mg(2+) and Fe concentrations of forest streams were lower than those of swamp streams, while the concentrations of total N, total P, Cl-, K+, and Na+ were in adverse. In both of the streams, the contents of heavy metal elements such as Fe, Mn, Cu, Zn, Cd, Hg and Pb were lower than the class I in Environmental Quality Standards for Surface Water (EQSSW) of China. The concentrations of total N and P in forest streams were (0.27 +/- 0.04) mg x L(-1) and (0.040 +/- 0.005) mg x L(-1), respectively, being significantly higher than those ((0.21 +/- 0.02) mg x L(-1) and (0.025 +/- 0.004) mg x L(-1)) in swamp streams. Swamp wetland had a stronger ability in depositing and adsorbing N and P, with more NH4(+) -N adsorbed than NO3(-) -N, and also had a stronger ability on the reduction and release of Fe, with the Fe content ((0.26 +/- 0.05) mg x L(-1)) in its streams obviously higher than that in forest streams.

Ecosystem↗
PubMed2006

Parasites of carnivorous mammals in Białowieza Primeval Forest.

BACKGROUND: Although the parasitofauna of wild carnivorous mammals in Poland is quite well recognized, there has been only one research carried on this issue so far in Białowieza Forest--the last lowland primeval forest of temperate zone in Europe. MATERIAL AND METHODS: Twelve wild and two domestic species of carnivorous mammals are living in Białowieza Forest. In our work faeces or intestines of all of them except ermine (Mustela erminea) have been examined and parasites or their eggs (or oocysts) recorded. In total 222 faecal probes from 13 species and 11 intestines of weasels have been investigated. RESULTS: All species of examined carnivorous mammals were infected with parasites. The most infected species has occurred red fox Vulpes vulpes (over 70% infected with parasites) meanwhile only about 30% of otters Lutra lutra were infected. We found at least three protozoan species, one trematode, one tapeworm and nine species of nematodes. Except trematode Alaria alata, all of them are reported for the first time from Białowieza Primeval Forest. Oocysts of coccidia have been found in faeces of nine host species, with the highest prevalence (29.4%) in badger. Six species of carnivorous mammals have been occurred infected with trematodes (highest prevalence 42.1% in wolves) and two with tapeworms (Diphyllobothrium latum with the prevalence 2.6% in otter and 31.6% in wolves). All examined host species were infected with nematodes (with prevalence from 14.7% in lynx to 72.7% in red fox). Results of our work should be treated as preliminary researches on the species composition of parasitic fauna invading carnivorous mammals in Białowieza Primeval Forest.

Animals↗
PubMed2006

Bionomics studies of Mansonia mosquitoes inhabiting the peat swamp forest.

The present study was conducted in the years 2000-2002 to determine the bionomics of Mansonia mosquitoes, vectors of nocturnally subperiodic Brugia malayi, inhabiting the peat swamp forest, "Phru Toh Daeng", Narathiwat Province, Thailand. Fifty-four species of mosquitoes belonging to 12 genera were added, for the first time, to the list of animal fauna in the peat swamp forest. Mansonia mosquitoes were the most abundant (60-70%) by all collection methods and occurred throughout the year with a high biting density (10.5-57.8 bites per person-hour). Ma. bonneae was most prevalent (47.5%) and fed on a variety of animal hosts, including domestic cats, cows, monkeys, and man with a maximum biting density of 24.3 bites per person-hour in October. The infective bites were found for the first time in Ma. annulata collected at Ban Toh Daeng (13 00-14 00 hours) and also Ma. bonneae at forest shade (16 00-17 00 hours) and in a village (20 00-21 00 hours) with rates of 0.6, 1.1 and 1.0%, respectively. The biting activities of these two species occurred in both the day and night time, with two lower peaks at 10 00 hours (18.5 bites per person-hour) and 13 00-15 00 (8.5-10.0 bites per person-hour) hours, but the highest peak was 19 00-21 00 hours (31.5-33.0 bites per person-hour) The biting activity patterns corresponded with the periodicity found in man and domestic cats and may play an important role in either transmission or maintenance of the filarial parasites in the peat swamp forest. The relative role of Ma. bonneae and Ma. uniformis in different environmental settings (primary swamp forest and open swamp) on the transmission of nocturnally subperiodic B. malayi merits further study.

Animals↗
PubMed2006

[Eco-hydrological characteristics of a subtropical evergreen broadleaved forest in Japan].

A three years (1998-2000) observation on the eco-hydrological characteristics of Castanopsis sieboldii and Schima wallichii dominated subtropical evergreen broadleaved forest on the Okinawa Island of Japan showed that during the observation period, the mean annual precipitation was 3325 mm, and 42.3% of it was directly or indirectly contributed by typhoon rainfall, implying that typhoon played a very important role in the hydrology of the forest. Through-fall and stem-flow contributed to 53.9% and 30.9% of the annual rainfall, respectively. The higher stem-flow could be due to the high wind velocity, intense rainfall, and the crown morphology of dominant species C. sieboldii with inclined branches and concave-shaped leaves. Interception loss occupied 15.2% of the total rainfall, being the lowest in the range of 15%-30% widely reported for many broadleaved evergreen forests. The annual surface runoff and lateral flow were 1092 mm and 613 mm, respectively, and the high proportion of surface runoff (32.8%) was probably due to the poor physical properties of soil, particularly the low noncapillary porosity (8%-12%), high clay content (51.9%-60.5%), and low infiltration rate (12 ml x min(-1)) in deeper soil layers. The effective and maximum water storage capacity of 0-70 cm soil layer were 85 mm and 324 mm, respectively, and the maximum water-holding capacity of forest floor was 2. 8 mm, which were close to or lower than those of the subtropical and tropical rain forests in China.

Conservation of Natural Resources↗