Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “forest”

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.

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

At least 559 records · Page 31Linked to original sources
PubMed2005

Climatic influences on net ecosystem CO2 exchange during the transition from wintertime carbon source to springtime carbon sink in a high-elevation, subalpine forest.

The transition between wintertime net carbon loss and springtime net carbon assimilation has an important role in controlling the annual rate of carbon uptake in coniferous forest ecosystems. We studied the contributions of springtime carbon assimilation to the total annual rate of carbon uptake and the processes involved in the winter-to-spring transition across a range of scales from ecosystem CO2 fluxes to chloroplast photochemistry in a coniferous, subalpine forest. We observed numerous initiations and reversals in the recovery of photosynthetic CO2 uptake during the initial phase of springtime recovery in response to the passage of alternating warm- and cold-weather systems. Full recovery of ecosystem carbon uptake, whereby the 24-h cumulative sum of NEE (NEEdaily) was consistently negative, did not occur until 3-4 weeks after the first signs of photosynthetic recovery. A key event that preceded full recovery was the occurrence of isothermality in the vertical profile of snow temperature across the snow pack; thus, providing consistent daytime percolation of melted snow water through the snow pack. Interannual variation in the cumulative annual NEE (NEEannual) was mostly explained by variation in NEE during the snow-melt period (NEEsnow-melt), not variation in NEE during the snow-free part of the growing season (NEEsnow-free). NEEsnow-melt was highest in those years when the snow melt occurred later in the spring, leading us to conclude that in this ecosystem, years with earlier springs are characterized by lower rates of NEEannual, a conclusion that contrasts with those from past studies in deciduous forest ecosystems. Using studies on isolated branches we showed that the recovery of photosynthesis occurred through a series of coordinated physiological and biochemical events. Increasing air temperatures initiated recovery through the upregulation of PSII electron transport caused in part by disengagement of thermal energy dissipation by the carotenoid, zeaxanthin. The availability of liquid water permitted a slightly slower recovery phase involving increased stomatal conductance. The most rate-limiting step in the recovery process was an increase in the capacity for the needles to use intercellular CO2, presumably due to slow recovery of Rubisco activity. Interspecific differences were observed in the timing of photosynthetic recovery for the dominant tree species. The results of our study provide (1) a context for springtime CO2 uptake within the broader perspective of the annual carbon budget in this subalpine forest, and (2) a mechanistic explanation across a range of scales for the coupling between springtime climate and the carbon cycle of high-elevation coniferous forest ecosystems.

Carbon↗
PubMed2005

Climatically induced interannual variability in aboveground production in forest-tundra and northern taiga of central Siberia.

To investigate the variability of primary production of boreal forest ecosystems under the current climatic changes, we compared the dynamics of annual increments and productivity of the main components of plant community (trees, shrubs, mosses) at three sites in the north of Siberia (Russia). Annual radial growth of trees and shrubs was mostly defined by summer temperature regime (positive correlation), but climatic response of woody plants was species specific and depends on local conditions. Dynamics of annual increments of mosses were opposite to tree growth. The difference in climatic response of the different vegetation components of the forest ecosystems indicates that these components seem to be adapted to use climatic conditions during the short and severe northern summer, and decreasing in annual production of one component is usually combined with the increase of other component productivity. Average productivity in the northern forest ecosystems varies from 0.05 to 0.14 t ha(-1) year(-1) for trees, from 0.05 to 0.18 t ha(-1) year(-1) for shrubs and from 0.54 to 0.66 t ha(-1) year(-1) for mosses. Higher values of tree productivity combined with lower annual moss productivity were found in sites in northern taiga in comparison with forest-tundra. Different tendencies in the productivity of the dominant species from each vegetation level (trees, shrubs, mosses) were indicated for the last 10 years studied (1990-1999): while productivity of mosses is increasing, productivity of trees is decreasing, but there is no obvious trend in the productivity of shrubs. Our results show that in the long term, the main contribution to changes in annual biomass productivity in forest-tundra and northern taiga ecosystems under the predicted climatic changes will be determined by living ground cover.

Biomass↗
PubMed2005

Contrasting patterns of soil N-cycling in model ecosystems of Fennoscandian boreal forests.

The low plant productivity of boreal forests in general has been attributed to low soil N supply and low temperatures. Exceptionally high productivity occurs in toe-slope positions, and has been ascribed to influx of N from surrounding areas and higher rates of soil N turnover in situ. Despite large apparent natural variations in forest productivity, rates of gross soil N mineralization and gross nitrification have never been compared in Fennoscandian boreal forests of contrasting productivity. We report contrasting patterns of soil N turnover in three model ecosystems, representing the range in soil C-to-N ratios (19-41) in Fennoscandian boreal forests and differences in forest productivity by a factor close to 3. Gross N mineralization was seven times higher when soil, microbial, and plant C-to-N ratios were the lowest compared to the highest. This process, nitrification and potential denitrification correlated with inorganic, total and microbial biomass N, but not microbial C. There was a constant ratio between soil and microbial C-to-N ratio of 3.7+/-0.2, across wide ratios of soil C-to-N and fungi-to-bacteria. Soil N-cycling should be controlled by the supplies of C and N to the microbes. In accordance with plant allocation theory, we discuss the possibility that the high fungal biomass at high soil C-to-N ratio reflects a particularly high supply of plant photosynthates, substrates of high-quality C, to mycorrhizal fungi. Methods to study soil N turnover and N retention should be developed to take into account the impact of mycorrhizal fungi on soil N-cycling.

Bacteria↗
PubMed2006

Woody debris contribution to the carbon budget of selectively logged and maturing mid-latitude forests.

Woody debris (WD) is an important component of forest C budgets, both as a C reservoir and source of CO2 to the atmosphere. We used an infrared gas analyzer and closed dynamic chamber to measure CO(2) efflux from downed coarse WD (CWD; diameter>or=7.5 cm) and fine WD (FWD; 7.5 cm>diameter>or=2 cm) to assess respiration in a selectively logged forest and a maturing forest (control site) in the northeastern USA. We developed two linear regression models to predict WD respiration: one based on WD temperature, moisture, and size (R2=0.57), and the other on decay class and air temperature (R2=0.32). WD respiration (0.28+/-0.09 Mg C ha-1 year-1) contributed only approximately 2% of total ecosystem respiration (12.3+/-0.7 Mg C ha-1 year-1, 1999-2003), but net C flux from CWD accounted for up to 30% of net ecosystem exchange in the maturing forest. C flux from CWD on the logged site increased modestly, from 0.61+/-0.29 Mg C ha-1 year-1 prior to logging to 0.77+/-0.23 Mg C ha-1 year-1 after logging, reflecting increased CWD stocks. FWD biomass and associated respiration flux were approximately 7 times and approximately 5 times greater, respectively, in the logged site than the control site. The net C flux associated with CWD, including inputs and respiratory outputs, was 0.35+/-0.19 Mg C ha-1 year-1 (net C sink) in the control site and -0.30+/-0.30 Mg C ha-1 year-1 (net C source) in the logged site. We infer that accumulation of WD may represent a small net C sink in maturing northern hardwood forests. Disturbance, such as selective logging, can enlarge the WD pool, increasing the net C flux from the WD pool to the atmosphere and potentially causing it to become a net C source.

Biomass↗
PubMed2006

Average body length of arboreal and aerial beetle (Coleoptera) assemblages from remnant and plantation Eucalyptus forests in southwestern Australia.

We examined body length differences between the beetle fauna of Eucalyptus plantation forests and remnant Eucalyptus forest in the same region using aerial and arboreal sampling. Mean body length of plantation-using species was greater than for remnant forest species, and the same pattern was apparent in the mean of all individuals collected regardless of species. This pattern was true for both Malaise-trap-collected beetles (aerial) and canopy-collected (arboreal) beetles. The tendency for plantation-restricted species to have longer bodies is significant even if clade is treated as a random factor in the analysis. Greater body length among plantation-using species is consistent with a few other studies that have found body size of insect species in early successional environments is typically greater than in late successional environments. Some studies suggest that larger species are better dispersers, which can rapidly colonise early successional habitats. In this study, however, there was little relationship between body length and the number of sites occupied; suggesting dispersal was not a major determinant of community membership. Two different patterns in this study support the hypothesis that body size differences are linked to trophic structure of the communities. First, the body length shift comparing remnant users to plantation users was greater among phytophages than for predators or saprophages. Second, saprophages were typically smaller than phytophages, and constituted a larger fraction of the remnant forest using fauna, driving down the mean body length in the saprophage-rich remnant forest community.

Agriculture↗
PubMed1998

Shinrin-yoku (forest-air bathing and walking) effectively decreases blood glucose levels in diabetic patients.

The influence of "shinrin-yoku" (forest-air bathing and walking) on blood glucose levels in diabetic patients was examined. Eighty-seven (29 male and 58 female) non-insulin-dependent diabetic patients [61 (SEM 1) years old] participated in the present study. Shinrin-yoku was performed nine times over a period of 6 years. The patients were divided into two parties. They then walked in the forest for 3 km or 6 km according to their physical ability and/or the existence of diabetic complications. The mean blood glucose level after forest walking changed from 179 (SEM 4) mg.100 ml-1 to 108 (SEM 2) mg.100 ml-1 (P < 0.0001). The level of glycated haemoglobin A1c also decreased from 6.9 (SEM 0.2)% (before the first shinrin-yoku) to 6.5 (SEM 0.1)% (after the last shinrin-yoku; P < 0.05). Blood glucose values declined by 74 (SEM 9) mg.100 ml-1 and 70 (SEM 4) mg.100 ml-1 after short- and long-distance walking respectively. There was no significant difference between these values. Since the forest environment causes changes in hormonal secretion and autonomic nervous functions, it is presumed that, in addition to the increased calorie consumption and improved insulin sensitivity, walking in a forest environment has other beneficial effects in decreasing blood glucose levels.

Baths↗
PubMed2006

Using of high-resolution topsoil magnetic screening for assessment of dust deposition: comparison of forest and arable soil datasets.

Magnetic susceptibility (kappa) is an easily detectable geophysical parameter that can be used as a proxy or semi-quantitative tracer of atmospheric industrial and urban dusts deposited in topsoil. An enhanced kappa value of topsoil is in many cases also associated with high concentrations of soil pollutants (mostly heavy metals). High-resolution magnetic screening of topsoil in areas of high pollution influx is a useful tool for detection of pollution "hot spots". General and regional screening maps with a grid density of 10 or 5 km have been performed on the basis of forest topsoil measurement only. The purpose of this study was to perform high-resolution magnetic screening with different grid densities in both forested and agricultural areas (arable land). Our large study area (ca. 200 km(2)) was located in a relatively more polluted region of the central part of Upper Silesia, and a second (small) one (ca. 100 m(2)) was located in the western part of Upper Silesia, with considerably lower influx of pollution. In the framework of this study, we applied a statistical comparison of data obtained in forested areas and on arable land. The arable soil showed statistically significantly lower kappa values, the result of "physical dilution" of the arable layer caused by annual ploughing. Thus arable soils must be avoided during high-resolution field measurement. From semivariograms, it was clear that the spatial correlations in forest topsoil are much stronger than in arable soil, which suggests that a denser measurement grid is required in forested areas.

Dust↗
PubMed2006

Impact of degradation on nitrogen transformation in a forest ecosystem of India.

A study was performed selecting one protected forest and an adjacent degraded forest ecosystem to quantify the impact of forest degradation on soil inorganic nitrogen, fine root production, nitrification, N-mineralization and microbial biomass N. There were marked seasonal variations of all the parameters in the upper 0-10 and lower 10-20 cm depths. The seasonal trend of net nitrification and net N-mineralization was reverse of that for inorganic nitrogen and microbial biomass N. Net nitrification, net N-mineralization and fine root biomass values were highest in both forests during rainy season. On contrary, inorganic nitrogen and microbial biomass N were highest during summer season.There was a marked impact of forest degradation on inorganic nitrogen, fine root production nitrification, N-mineralization and microbial biomass observed. Soil properties also varied with soil depth. Fine root biomass, nitrification, N-mineralization and microbial biomass N decreased significantly in higher soil depth. Degradation causes decline in mean seasonal fine root biomass in upper layer and in lower depth by 37% and 27%, respectively. The mean seasonal net nitrification and N-mineralization in upper depth decreased by 42% and 37%, respectively and in lower depth by 42.21% and 39% respectively. Similarly microbial biomass N also decreased by 31.16% in upper layer 33.19% in lower layer.

Ammonia↗
PubMed1977

A yellow fever epizootic in Zika forest, Uganda, during 1972: Part 1: Virus isolation and sentinel monkeys.

The results of the yellow fever immunity survey of Central and East Africa reported by SAWYER & WHITMAN in 1936 prompted scientists to undertake well-planned epidemiological studies on yellow fever in eastern Africa. A Yellow Fever Research Institute (the present East African Virus Research Institute) was established at Entebbe in 1936 for this purpose. One of the areas where much work has been carried out is a strip of typical tropical forest, the Zika Forest, 12 kilometres from the Institute. Routine surveillance work, particularly on the biting activity of the yellow fever vector mosquitoes, has been going on since 1946. It was during one of these studies in 1972 that the first yellow fever virus strain was isolated from Aedes africanus collected from the Zika and Sisa forests and one strain was isolated from Coquillettidia fuscopennata, also from the Zika Forest. Three sentinel rhesus monkeys, nomimmune to YF, which were kept in the Zika Forest during the time of the epizootic died of YF disease. The present observations indicate that YF is still present in Africa, and as such it still remains a potential menace to the human population. The epidemiological implications are discussed.

Aedes↗
PubMed1984

Characterization of Barmah forest virus: an alphavirus with some unusual properties.

Barmah Forest virus has been characterized in a number of ways including electron microscopy of infected cells; physical studies of the virion, its RNA, and associated proteins; N-terminal sequence analysis of the two envelope glycoproteins; studies of macromolecular species present in infected cells; and serological cross-reactions with alphaviruses and bunyaviruses. From these results Barmah Forest virus is clearly an alphavirus since the structure of the virion, the mode of replication, and the macromolecular species present in infected cells are typical of alphaviruses. The N-terminal regions of the two glycoproteins E1 and E2 show extensive sequence homology (approximately 50%) with those of other alphaviruses. Barmah Forest virus cross-reacts in hemagglutination inhibition tests, although not in complement fixation tests or infectivity neutralization tests, with other alphaviruses. In some of its properties Barmah Forest virus is unusual, however. It cross-reacts in complement fixation and hemagglutination inhibition tests with Umbre virus, a bunyavirus, which originally led it to be classified as a bunyavirus; the glycosylation pattern of E2 of Barmah Forest virus appears to differ from that of other alphaviruses; and the sedimentation coefficient of the virion appears to be slightly less than that of other alphaviruses.

Aedes↗
PubMed1992

Measurement of the dry deposition flux of NH3 on to coniferous forest.

The dry deposition flux of NH3 to coniferous forest was determined by the micrometeorological gradient method using a 36 m high tower. Aerodynamic characteristics of the site were studied, using a second tower erected in the forest 100 m from the first. Fluxes and gradients of heat and momentum measured on both towers indicated a fairly homogeneous turbulent flow field over the studied area of the forest. Site specific flux profile functions for heat were derived from continuous measurements of turbulent fluxes and gradients. These functions were used to derive fluxes from the observed gradients of NH3. In total, eighty 90-min NH3 flux runs were performed. The results indicate a strong nonstomatal uptake of NH3 by the forest. A representative dry deposition velocity for NH3 of 3.6 cm(-1) s was derived. The annual average flux was roughly estimated to be equivalent to 50 kg N ha(-1) yr, significantly higher than the critical load for coniferous forest.

Journal Article↗
PubMed1993

Dissolved inorganic nitrogen budget for a forested catchment at Beddgelert, North Wales.

An input-output budget for dissolved inorganic-N in a small forested catchment in North Wales is presented. From 1982 to 1990, bulk precipitation inputs averaged 10.3 kg ha(-1) year(-1), whereas throughfall inputs in 1983-1984 were 20.3 kg ha(-1) year(-1). Streamwater outputs were consistently larger than bulk precipitation inputs, averaging 14.6 kg ha(-1) year(-1). Inorganic-N in the forest stream was predominantly nitrate and concentrations were substantially higher than in a nearby moorland stream. Both streams showed seasonal trends in nitrate concentration, with highest concentrations occurring in summer in the forest stream but in winter in the moorland stream. Nitrate concentration in the forest stream increased with increasing soil temperature up to approximately 7 degrees C and decreased at higher temperatures. Nitrification is thought to be responsible for nitrate production at temperatures both below and above 7 degrees C, but root uptake becomes significant only at the higher temperatures. In the forest, dry deposition and cloudwater inputs of inorganic-N are responsible for increased nitrogen fluxes in throughfall compared with wet deposition. Mineralization and nitrification in excess of plant needs causes the organic soil horizons to act as a net source of dissolved inorganic-N. Nitrogen transformations in the soil lead to soil acidification at a rate of 1.0 keq ha(-1) year(-1).

Journal Article↗
PubMed1996

Nitrogen deposition in California forests: a review.

Atmospheric concentrations and deposition of the major nitrogenous (N) compounds and their biological effects in California forests are reviewed. Climatic characteristics of California are summarized in light of their effects on pollutant accumulation and transport. Over large areas of the state dry deposition is of greater magnitude than wet deposition due to the arid climate. However, fog deposition can also be significant in areas where seasonal fogs and N pollution sources coincide. The dominance of dry deposition is magnified in airsheds with frequent temperature inversions such as occur in the Los Angeles Air Basin. Most of the deposition in such areas occurs in summer as a result of surface deposition of nitric acid vapor (HNO3) as well as particulate nitrate (NO3-) and ammonium (NH4+). Internal uptake of gaseous N pollutants such as nitrogen dioxide (NO2), nitric oxide (NO), HNO3, peroxyacetyl nitrate (PAN), ammonia (NH3), and others provides additional N to forests. However, summer drought and subsequent lower stomatal conductance of plants tend to limit plant utilization of gaseous N. Nitrogen deposition is much greater than S deposition in California. In locations close to photochemical smog source areas, concentrations of oxidized forms of N (NO2, HNO3, PAN) dominate, while in areas near agricultural activities the importance of reduced N forms (NH3, NH4+) significantly increases. Little data from California forests are available for most of the gaseous N pollutants. Total inorganic N deposition in the most highly-exposed forests in the Los Angeles Air Basin may be as high as 25-45 kg ha(-1) year(-1). Nitrogen deposition in these highly-exposed areas has led to N saturation of chaparral and mixed conifer stands. In N saturated forests high concentrations of NO3- are found in streamwater, soil solution, and in foliage. Nitric oxide emissions from soil and foliar N:P ratios are also high in N saturated sites. Further research is needed to determine the ecological effects of chronic N deposition, and to develop appropriate management options for protecting water quality and managing plant nutrient resources in ecosystems which no longer retain excess N.

Journal Article↗
PubMed2005

Contrasting lead speciation in forest and tilled soils heavily polluted by lead metallurgy.

The concentration trends and chemical fractionation of Pb was studied in eight tilled and forest soil profiles heavily polluted by Pb metallurgy in the Pribram district, Czech Republic. The highest Pb concentrations were observed in surface and subsurface horizons attaining 35,300 mg kg-1 in forest soils and 1233 mg kg-1 in tilled soils. Total Pb concentrations were one order of magnitude lower in tilled soil due to intensive ploughing and annual crop off-take. The results of the Tessier sequential extraction procedure showed the preferential binding of Pb in forest soils to operationally-defined exchangeable positions and soil organic matter (oxidisable fraction). The Pb exchangeable fraction is thought to correspond to weak electrostatic binding on the functional groups of organic matter. In tilled soil, Pb is predominantly bound to operationally-defined Fe and Mn oxides (reducible fraction). A comparison with the background Pb concentration values showed a strong contamination even in mineral horizons IIC and confirmed a strong vertical mobility of Pb within the soil profiles. The calculated mobility factors (MF) showed that up to 72% of Pb is mobile and bioavailable in forest soils. In contrast, the bioavailability of Pb in tilled soils was significantly lower as the MF accounted for up to 30%. In the most polluted horizon of forest soil profile, the X-ray powder diffraction (XRPD) analysis confirmed the presence of anglesite (PbSO4), derived likely from the smelter emissions.

Agriculture↗
PubMed2006

Chemical and biological characterization of dissolved organic matter from silver fir and beech forest soils.

Despite a growing attention to the dissolved organic matter (DOM) in terrestrial ecosystems and evidence of the fact that vegetation affects the quality of both undissolved and dissolved organic matter in soil, the role of DOM as a biological indicator is still poorly understood. In this work, the fertility of 59 sites, divided into eight key alliances of the order Fagetalia sylvaticae Pawl., was studied considering chemical and biological parameters such as soil DOM, hormone-like activity, low-molecular-weight (LMW) aliphatic and phenolic acids, and floristic data. Both non-parametric tests and principal component analysis (PCA) revealed differences between silver fir and beech forests and within each type of forest. There were also differences between neutrophilous and acidophilous types. What's more, PCA reveals the dominance of the auxin (IAA)-like activity, and of some phenolic acids in distinguishing the acidophilous beeches (ACI) form the other types, whereas the gibberellin (GA)-like activity is more relevant in neutrophilous conditions such as thermophilous (THE) and mesophilous (MESO) beeches and montane (MO), high montane (HMA), high montane (HMC) silver fir forests. The GA-like activity is also related to the succinic, fumaric, malonic, and l-malic acids in the MO, HMA and HMC silver fir forests. Moreover, the role of LMW aliphatic acids in mobilizing the hormone-like activity, which improves forest growth, is stressed. The growth of seedlings of Picea abies was influenced by the phenolic acid content. At concentrations between 1 and 100 microM, phenylacetic and protocatechuic acids inhibited root growth to the same extent as indoleacetic acid, while p-hydroxybenzoic acid had a stimulating effect comparable to that of gibberellic acid. The aliphatic and phenolic acids appear to be related to plant strategies that influence soil fertility affecting plant growth through rhizodeposition. The role of LMW aliphatic and phenolic acids as molecular markers of ecosystem function is noted.

Abies↗
PubMed2004

The impacts of logging on the microhabitats used by two species of couas in the western forest of Madagascar.

Habitat structure is important to consider in all ecological studies considering the relationships between animals and their environment. Habitat structure can be studied at different scales, from landscape to microhabitat. I studied here the response of two endemic terrestrial birds living in the dry forest of Madagascar. These birds belong to the genus Coua. The study is made at the microhabitat scale in a gallery forest, which has been logged selectively in order to limit the degradation of the forest. Selective logging is promoted to be respectful of the environment by allowing us to exploit the forest without destroying it and the wildlife encountered here. At the microhabitat scale, I underline that selective logging does not affect the Coquerel's coua, which can exploit new microhabitats and increase its density. On the other hand, the giant coua was affected by the restriction of optimal microhabitats for foraging. This species could be adapted to the new habitat by modifying its favourite foraging sites, but by decreasing also the population density. This species was affected by forest degradation, even considered as not destroying. At last, I considered how Coquerel's coua could be used as umbrella species for the endangered mesite.

Animals↗
PubMed2004

Heavy metal concentrations in Enchytraeidae (Oligochaeta) in the Niepołomice Forest.

Enchytraeidae were investigated as a part of a broad study of Niepolomice Forest ecosystem functioning. Animals were collected in oak-hornbeam (Tilio-Carpinetum) and in mixed oak-pine (Pino-Quercetum) stands. The highest cadmium concentration was observed in oak-hornbeam from the northern part of the forest (32.33+/-23.22 mg kg(-1) dry mass), with lower ones in mixed oak-pine (13.60+/-21.42 mg kg(-1) dry mass) and southern oak-hornbeam stands (11.84+/-7.52 mg kg(-1) dry mass). Lead concentrations were higher in mixed oak-pine (47.73+/-23.36 mg kg(-1) dry mass) and southern oak-hornbeam (52.20+/-45.19 mg kg(-1) dry mass) stands than in northern, oak-hornbeam (9.20+/-6.46 mg kg(-1) dry mass). The copper concentration was similar in animals from all forest types studied (147.94+/-106.38 mg kg(-1) dry mass in mixed oak-pine, 138.35+/-64.76 mg kg(-1) dry mass in northern oak-hornbeam, and 138.27+/-80.08 mg kg(-1) dry mass in southern oak-hornbeam). The lowest concentration of zinc in animals was found in northern oak-hornbeam (1015.27+/-300.28 mg kg(-1) dry mass) and higher concentrations, in mixed oak-pine (2233.81+/-1825.41 mg kg(-1) dry mass) and southern oak-hornbeam (2366.60+/-1987.52 mg kg(-1) dry mass). The concentrations of available metals in litter trended with those in the animals, but only the relation between lead concentration in animals and available lead in litter was significant. The spatial distribution of metal concentrations in the whole forest suggests a relationship between forest type and the content of cadmium, lead, and zinc in animals. The spatial distribution of heavy metal content in enchytraeids was investigated in selected plots as well. The coefficients of variation indicated that lead had the most diverse distribution and zinc the most homogeneous.

Animals↗
PubMed2004

Evaluation of air pollution-related risks for Austrian mountain forests.

The present paper describes air pollution status and evaluation of risks related to effects of phytotoxic pollutants in the Austrian mountain forests. The results are based on Austrian networks (Forest Inventory, Forest Damage Monitoring System, Austrian Bioindicator Grid), the Austrian sample plots of the European networks of the UN-ECE (ICP Forests, Level I and Level II) and interdisciplinary research approaches. Based on the monitoring data and on modelling and mapping of Critical Thresholds, the evaluation of risk factors was possible. Cause-effect relationships between air pollution and tree responses were shown by tree-physiological measurements. Sulfur impact, proton and lead input, concentrations of nitrogen oxides, nitrogen input and ozone were evaluated. The risk was demonstrated at a regional and large-scale national level. Especially the increasing O(3) level and the accumulation of Pb with altitude present most serious risk for mountain forests.

Air Pollutants↗