Long-term sustainability of forest ecosystems on sandstone in the Vosges Mountains (France) facing atmospheric deposition and silvicultural change

Since the 1980s, atmospheric deposition acidity has generally decreased in European forest ecosystems. However, at many sites, little or no sign of recovery has been observed yet. Concerns are rising about the sustainability of these ecosystems because of reduced nutrients inputs in atmospheric deposition and the increase in biomass harvesting to supply bio-energy.We used a silver fir plot of the French monitoring network (RENECOFOR, site SP57) typical of the ecosystems on sandstone in the Vosges Mountains, to investigate its functioning and its response facing past and possible future changes. We (1) calculated 12-year-mean “input-output” nutrient budgets, (2) measured the change in soil exchangeable cations and anions, (3) used monitoring data to calibrate a process oriented biogeochemical model, NuCM, that was then used to (4) simulate the consequences of two main scenarios and their combinations: constant or reduced atmospheric deposition, and traditional or whole-tree harvesting.Mean term changes in exchangeable nutrients and input-output budgets showed a loss of exchangeable sulphate and base cations, the level of which depended on the method. This combined efflux induced an acidification of soil solution and an alkalinisation of the soil. The model NuCM was successfully calibrated and scenarios were implemented. A slight recovery was simulated when deposition was maintained constant but combined acid and nutrient atmospheric deposition reduction delayed recovery. Whole-tree harvesting drastically decreased soil fertility compared to traditional silviculture. Hence, biomass harvesting in forests on poor soils may counter recovery in the future.     

长白山阔叶红松林林地附近湍流特征分析

2001年8月使用三维超声风温仪(IA-SA 485)测定并分析了中国科学院长白山森林生态系统开放站阔叶红松林样地(12828扙,4224?N,吉林省,中国)林地附近湍流特征。发现林地附近气流具有高度间歇性和不对称性,并为活跃的向上运动主导。垂直方向的湍流受到抑制,其时间尺度和长度尺度都小于水平两个分量的相应值,林地附近的气团呈偏平结构。热力作用对当地湍流产生和维持过程起到了主导作用。图4表3参15。     

Analyses of the impact of changes in atmospheric deposition and climate on forest growth in European monitoring plots: A stand growth approach

During the last 15 years a number of studies have shown increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. We have here used data from intensive monitoring plots spread over Europe for a five year period in order to examine the influence of environmental factors on forest growth. Evaluations focussed on the influence of nitrogen, sulphur and acid deposition, temperatures, precipitation and on a drought index calculated as deviation from the long-term mean. The study included the main tree species Norway spruce, Scots pine, common beech as well as European and sessile oak and was based on data from 363 plots. As many other factors besides nitrogen and temperature influence tree growth, expected stem volume increments were modelled using site productivity, stand age and a stand density index. Relative volume increment was then calculated as actual increment in % of expected increment. The site productivity, assumed to be given by site conditions and past environmental conditions, was either taken from expert estimates or computed from site index curves from northern, central and southern Europe. The model explained between 18% and 39% of the variance with site productivity being positively related and age negatively related to actual increment. The various models and statistical approaches were fairly consistent, and indicated a fertilizing effect of nitrogen deposition, with slightly above one percent increase in volume increment per kg of nitrogen deposition per ha and year. This was most clear for spruce and pine, and most pronounced for plots having soil C/N ratios above 25. Also, we found a positive relationship between relative increment and summer temperature, i.e. May–August mean temperature deviation from the 1961–1990 means. The cause–effect relationship here is, however, less certain. Other influences were uncertain. Possibly, sulphur and acid deposition have effects on growth, but these effects are obscured by, and outweighed by the positive effect of nitrogen deposition, because of collinearity between these variables. Drought effects were uncertain also, and one reason for this might be large uncertainties in the precipitation data: precipitation measured on some 50% of the plots correlated poorly with the precipitation data obtained from Europe-wide databases. The major finding of this study was a positive relationship between higher than normal volume increment on one hand and nitrogen deposition on the other hand.     

Advances of study on atmospheric methane oxidation （consumption） in forest soil

Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and related natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases concentrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenou saluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that OH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil.CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire.In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmos-pheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studiesfurther on CH4 oxidation in various forest soils of different areas.     

Acid deposition effects on forest composition and growth on the Monongahela National Forest,West Virginia

The northern and central Appalachian forests are subject to high levels of atmospheric acid deposition (AD), which has been shown in some forests to negatively impact forest growth as well as predispose the forest system to damage from secondary stresses. The purpose of this study was to evaluate the possible contribution of AD to changes in composition and productivity of the Monongahela National Forest, and to evaluate soil-based indicators of acidification that might be useful for detecting AD-related forest changes. Soils adjacent to 30 Forest Inventory and Analysis (FIA) sites were sampled and analyzed for a suite of acidity indicators. These indicators were correlated with the periodic mean annual volume increment (PMAVI) of the forest stands on FIA plots for the 10-yr period 1989–2000. PMAVI ranged from −9.5 to 11.8 m³ ha⁻¹ yr⁻¹, with lower-than-expected growth (<3 m³ ha⁻¹ yr⁻¹) on two-thirds of the sites. In the surface horizon, effective base saturation, Ca²⁺ concentration, base saturation, K⁺ concentration, Ca/Al molar ratio, and Mg/Al molar ratio, were positively correlated with PMAVI and Fe concentration was negatively correlated with PMAVI (p ≤ 0.1). In the subsurface horizon pH_(w) and effective base saturation were positively correlated and Al³⁻ concentration and K⁺ concentration were negatively correlated with PMAVI. We hypothesized that NO₃-N/NH₄-N ratio would also be correlated with PMAVI, but it was not. Correlations between soil chemical indicators and PMAVI suggest that AD may contribute, in part, to the lower-than-expected forest growth on the Monongahela National Forest.     

四川森林生物多样性现状及保护策略探讨

四川地处我国西南林区的主体部份,森林资源丰厚,森林生态系统复杂,森林生物在物种、生态系统、遗传信息三个层次上具有丰富度与多样性.为适应我国生物多样性的保护形势及要求,作者在分析森林生物多样性濒危现状及致危原因的基础上,对四川森林生物多样性的保护工作从八个方面探讨其策略.     

面向21世纪森林工程专业的现状与发展

本详细分析了森林工程专业现状，提出了21世纪森林工程专业发展思路。     

江苏省森林资源现状与特点分析

森林资源二类调查是获取各基层单位森林资源现状与分布的主要方法,根据江苏省2009年森林资源二类调查结果,笔者通过提取各类林地、林木、林种、乔木林、竹林和灌木林的组成及分布等森林资源主要数据,并对单位面积蓄积、单位面积株数和树种结构等因子进行了对比分析,客观地反映了江苏森林资源快速增加、幼中龄林占优势地位、非公有制林业快...     

Atmospheric deposition and impact of forest thinning on the throughfall of mountain forest ecosystems in the Bavarian Alps

The input into two forested watersheds in the Bavarian Alps is characterised by 2000 mm mean annual precipitation. Evaporation from the tree crown surfaces varies between 25 and 30%. The input is influenced by multiple natural and man-made processes. In addition to the general climate, these are local weather conditions, the growing season, processes of combustion (traffic and domestic fuel), tourism, farming, and not least by processes in the canopy. The input of SO₄-S is comparatively low, while high amounts of acidity and nitrogen are deposited. The input occurs mainly as dissolved salts. A considerable amount of the acidity deposited is buffered in the canopy by cation exchange and by calcareous dusts, which are blown out from the limestone and dolomite mountains nearby, and redeposited on leaf surfaces. Forest thinning (removal of 40% of the stem volume) caused marked changes in the deposition pattern. Interception and deposition rates of individual ions were reduced by up to 45%. The amount and chemical composition of the throughfall occupied an intermediate position between bulk precipitation and the throughfall of the control watershed. Ions which are preferentially exchanged and leached from the leaves, e.g. potassium and organic compounds, were affected the most.     

中国吉林森林生态网络现状与展望

本文概要介绍了吉林省生态环境概况、林业建设成就与问题,论述了本省森林生态网络建设面临的任务及亟待解决的八个方面的问题,并对生物技术、信息技术、新材料技术及无公害森林保健技术在森林生态网络建设的应用前景进行了展望。参9。     

Evaluation and mapping of relative sensitivity of the terrestrial ecosystems to acidic deposition in Fujian

Based on the semi-quantitative approach, four environmental factors of sites (i.e. bedrock lithology, soil type, land use, and rainfall) were categorized, weighted and combined to determine and assess the relative sensitivity of the terrestrial ecosystems to acidic deposition in Fujian Province. Then the factors have been digitized and combined to assign an overall value for each mesh square (16.77 km×18.39 km) by using the geographic information system (GIS) The results indicated that the most sensitive area in Fujian was mainly located in the southeast, and the least: ensitive area was distributed sporadically in the east along the coast. Due to slow weathering rate of siliceous rocks, acid to weakly acid reactions of the soils, along with the greater percent of coniferous forests, more than 80 percent of the total area exhibits higher sensitivity classes (4–7). This project is jointly sponsored by Forestry Administration of Fujian Province and Japan International Forestry Promotion and Cooperation Center (k99066). Fan Houbao, male, born in 1965, associate professor of Fujian Forestry College, Nanping 353001, P.R. China. Responsible editor: Zhu Hong     

森林资源清查中植被调查与统计技术研究

文章提出了利用森林资源连续清查固定样地进行植被种类和生物量调查的技术方法。此方法通过选择适当时间，提高调查者相关知识，确定样地数量等措施，可满足植物区系调查的要求，对于植被类型确定，植物蕴藏量统计，经济植物开发利用保护的决策，植被演替规律的观测具有实用价值。     

Ground floor vegetation assessment within the intensive (Level II) monitoring of forest ecosystems in Germany: chances and challenges

As a part of the ‘Intensive Forest Monitoring Programme’ of ICP Forests, ground floor vegetation has been surveyed along with parameters of other relevant components of the forest ecosystems and their environment at 80 permanent plots all over Germany. Its floristic composition and their changes can therefore be linked to a wide variety of potentially influencing factors, scrutinising recent hypotheses on floristic changes, mainly soil eutrophication and acidification due to air pollutants. Results of a broad-scaled feasibility study are presented and critically discussed with regard to future in-depth evaluations. After an overview on the most abundant species, the syntaxonomic allocation of the plots is given. An ordination reveals a gradient from nutrient and base rich soils to poor acidic soils. Floristic dynamics are mainly aligned with the main axis, but conclusions about the medium-term development cannot be stated yet. Ordination and subsequent statistics are recommended to open up a wide field for explorative investigations. Indicator values for soil acidity and nutrient supply corroborate the main floristic gradient. Based on an empirical species–area relationship (SAR), species numbers for a common plot size of 400 m² were calculated. Basic relationships among different diversity measures and between diversity measures and basic stand and site-related parameters were elaborated. Recommendations focus on enhancements of the assessment of ground floor vegetation within the context of the Level II monitoring like annual sampling or harmonisation of the plot sizes.     

我国森林水文研究现状及发展趋势概述

在简要介绍我国森林水文研究历史的基础上，概述了我国森林与降水、径流、蒸发散、水循环和水质等方面的研究现状及主要成果，并对我国森林水文研究的未来民展方向进行了初步分析。     

A comparative analysis of spatial, temporal, and ecological characteristics of forest fires in seasonally dry tropical ecosystems in the Western Ghats, India

The Western Ghats in India is one of the 25 global hotspots of biodiversity, and it is the hotspot with the highest human density. This study considers variations in the regional fire regime that are related to vegetation type and past human disturbances in a landscape. Using a combination of remote sensing data and GIS techniques, burnt areas were delineated in three different vegetation types and various metrics of fire size were estimated. Belt transects were enumerated to assess the vegetation characteristics and fire effects in the landscape. Temporal trends suggest increasingly short fire-return intervals in the landscape. In the tropical dry deciduous forest, the mean fire-return interval is 6 years, in the tropical dry thorn forest mean fire-return interval is 10 years, and in the tropical moist deciduous forest mean fire-return interval is 20 years. Tropical dry deciduous forests burned more frequently and had the largest number of fires in any given year as well as the single largest fire (9900 ha). Seventy percent, 56%, and 30% of the tropical moist deciduous forests, tropical dry thorn forests, and tropical dry deciduous forests, respectively have not burned during the 7-year period of study. The model of fire-return interval as a function of distance from park boundary explained 63% of the spatial variation of fire-return interval in the landscape. Forest fires had significant impacts on species diversity and regeneration in the tropical dry deciduous forests. Species diversity declined by 50% and 60% in the moderate and high frequency classes, respectively compared to the low fire frequency class. Sapling density declined by ca. 30% in both moderate and high frequency classes compared to low frequency class. In tropical moist deciduous ecosystems, there were substantial declines in species diversity, tree density, seedling and sapling densities in burned forests compared to the unburned forests. In contrast forest fires in tropical dry thorn forests had a marginal positive effect on ecosystem diversity, structure, and regeneration.     

Estimation of the carbon storage of forest vegetation and carbon emission from forest fires in Heilongjiang Province,China

The forest resource of Heilongjiang province has important position in china. On the basis of the six times of national forest inventory data （1973-1976, 1977-1981, 1985-1988, 1989-1993, 1994-1998, 1999-2003） surveyed by the Forestry Ministry of P. R. China from 1973 to 2003, the carbon storage of forests in Heilongjiang Province are estimated by using the method of linear relationship of each tree species between biomass and volume. The results show that the carbon storage of Heilongjiang forests in the six periods （1973-1976, 1977-1981, 1985-1988, 1989-1993, 1994-1998, 1999-2003） are 7.164×10^8 t, 4.871×10^8 t, 5.094×10^8 t, 5.292×10^8 t, 5.594×10^8 t and 5.410×10^8 t, respectively., which showed a trend of decreasing in early time and then increasing. It indicated that Heilongjiang forests play an important role as a sink of atmospheric carbon dioxide during past 30 years. Based on the data of forest fires from 1980 to 1999 and ground biomass estimation for some forest types in Heilongjiang Province, it is estimated that the amount of mean annual consumed biomass of forests is 391758.65t-522344.95t, accounting for 6.4%-8.4% of total national consummation from forest fires, and the amount of carbon emission is 176 291.39t-235 055.23t, about 8% of total national emission from forest fires. The emission of CO2, CO, CH4 and NMHC from forest fires in Heilongjiang Province are estimated at 581761.6-775682.25 t, 34892.275-46523.04 t, 14091.11-18788.15 t and 6500-9000 t, respectively, every year.     

Effects of forest landscape change and management on the range expansion of forest bird species in the Mediterranean region

In the western Mediterranean region of Catalonia (NE Spain), during the last 20 years of the 20th century, the range of many forest bird species has expanded. Our objective was to characterize the roles of (a) spatial population processes (related to dispersal), (b) changes in forest structure (due to forest maturation and management), and (c) landscape composition (resulting from afforestation and fires) in the range expansion of these bird species at the landscape scale (10 × 10 km). After correcting for the differences in sampling effort, colonizations appeared to be more likely near areas in which the species had been present in the 1980s. Patterns of the range expansion were also strongly associated with forest maturation, which seems to affect the spatial arrangement of birds at multiple scales. Changes in forest landscape composition due to afforestation and fires were minor determinants of range changes, and forest management did not seem to prevent range expansion at the spatial scale studied. Colonization events appeared to be driven primarily by landscape changes occurring in nearby localities rather than within the colonized locations themselves, presumably because of source–sink dynamics and connectivity patterns. Our results showed that in Catalonia, at a landscape scale, the impact of forest management on forest bird communities is much smaller than the impact of the widespread maturation of forests following a large-scale decline in traditional uses.     

Floristic diversity and composition of the Biteyu forest in the Gurage mountain chain (Ethiopia): implications for forest conservation

The Afromontane forests of Ethiopia have been under a serious degradation threat. Assessment of floristic diversity and species composition in Biteyu forest of Gurage mountain chain in the central Ethiopia was conducted to examine the pattern of forest structure. Thirty plots of 30 m×30 m were used to record the vegetation and environmental data using systematic sampling technique. The local name, plant scientific names, DBH, height,species abundance and percentage canopy cover of plant species were recorded. Shannon diversity index and Sorensen's coefficients was used for comparison among communities and similar forests in the country. Threats to the forest biodiversity in Biteyu were determined by counting cattle interference and wood stumps as disturbance indicators. Relative Euclidean Distance measures by using Ward's method(linkage) was applied for cluster analysis. Environmental variables were also recorded in each plot. Woody species population structure, basal area and importance value index were analyzed using spreadsheet programs. Data on species distribution and environmental variables in the forest were analyzed by canonical correspondence analysis. A total of 190 species in 154 genera under 73 families were identified. Twenty species were found to be endemic taxa to the Flora Area. Only three plant community types were identified from the cluster analysis due to the high human influence. The Sorensen's coefficient showed the resemblance of the Biteyu forest with other Dry Evergreen Afromontane forests in the country. Moreover, altitude and slope strongly affect the species composition and structure of Biteyu forest. Given the high anthropogenic influence, high endemism, high dependence of the local community on the forest resources, forest conservation and restoration measures should be done by stakeholders.     

The long-term effects of catchment liming and reduced sulphur deposition on forest soils and runoff chemistry in southwest Sweden

Whole catchment liming or forest liming has been proposed and implemented as a countermeasure to the effects of elevated sulphur deposition. Since the end of the 1980s the Swedish Forest Agency has undertaken experimental forest liming experiments in selected catchments in southern Sweden. These studies were with low doses (3 tonnes ha⁻¹) of lime (CaCO₃) and dolomite (CaMg(CO₃)₂). Data from both soil samples and stream water samples have been collected for the 16 years following treatment. The stream data has been complemented with data from untreated catchments, from the Swedish monitoring stream network. Significant differences due to treatment were seen for Ca, cation exchange capacity (CEC) and base saturation (BS) in the humus layer, none of these variables showed a statistically significant change in the mineral soil due to treatment alone. Soil samples from both the treated and untreated sites showed temporal changes in both the humus layer and the mineral soils with increases in pH, Ca and CEC and decreases in BS and Al which were independent of treatment. A combination of treatment and time, gave significant changes in BS and TA down to 10 cm in the mineral soil. In the stream water samples no statistically significant differences were observed between treated and untreated sites. Regardless of treatment, the streams exhibited a general pattern of declining concentrations of SO₄, Ca, sum of base cations (BC) and increasing acid neutralizing capacity (ANC). In summary, the application of a low dose of lime (3 tonnes ha⁻¹) did not result in significant changes in surface water chemistry in the study catchments and changes in soil chemistry were mainly restricted to the humus layer during the 16 years following treatment. The natural recovery, as a result of reductions in sulphur deposition, dominated the effects and was clearly seen in both the treated and untreated study sites. MAGIC simulations indicate that this recovery will continue in the coming decades.     

Bird communities and seedling recruitment in restoring seasonally dry forest using the framework species method in Northern Thailand

This study examined the effects of framework trees, planted in 1998, and bird community on the natural recruitment of tree seedling species in a forest restoration experiment designed to test the framework species method of forest restoration established by Chiang Mai University’s Forest Restoration Research Unit (FORRU-CMU). Tree seedlings establishing beneath five framework tree species: Erythrina subumbrans (Hassk.) Merr., Hovenia dulcis Thunb., Melia toosendan Sieb. & Zucc., Prunus cerasoides D.Don and Spondias axillaries Roxb., were surveyed. Five trees of each species were selected in the 8-year-old trial plots. Birds visiting each tree were observed to determine possible seed dispersal activities. Thirty-six tree seedling species were found beneath the selected trees, of which 11 were wind-dispersed and 25 were animal-dispersed. The population density of animal-dispersed tree seedlings was higher than the wind-dispersed seedlings beneath all selected framework trees. The sample plots beneath P. cerasoides supported the highest population density of tree seedlings. Forty-nine bird species were recorded visiting the framework trees between July 2006 and June 2007. Non-frugivorous birds were recorded more frequently than the frugivorous birds. The effects of birds on seedling recruitment were different among each of the selected framework tree. Bigger trees, which attracted high number of birds by providing food resources, roosting and nesting sites may increase the seed deposition more than smaller trees with fewer attractants.