北京市小龙门国家森林公园大型真菌名录

北京市小龙门国家森林公园大型真菌资源丰富。在保护区内共采集标本212号,鉴定出47种,隶属于2个门、7个目、20个科、47个种。     

Channels and ditches as the last shelter for freshwater mussels: the case of Margaritifera auricularia and other naiads inhabiting the mid Ebro River Basin,Spain

• 1. Freshwater mussels or naiads are generally considered to thrive in river habitats, provided the ecological conditions are good. The presence of populations of these bivalves in artificial channels and ditches with natural bottoms has only scarcely been reported. The aim of this paper was to present the idea that these ‘channel’ and ‘ditch’ habitats could in fact be a sanctuary for naiads.
• 2. Approximately 80 km of several of these waterways fed by the mid Ebro River were sampled in Spain to monitor their naiad populations. Observations indicate that these habitats harbour substantial colonies of freshwater mussels (including two populations of adult specimens of the endangered species Margaritifera auricularia), much more so than the corresponding river.
• 3. The authors wish to alert conservation authorities and freshwater mussel experts to the extreme fragility and importance of this kind of habitat for the long‐term conservation of these imperilled molluscs.

Copyright © 2008 John Wiley & Sons, Ltd.     

Do forest and health professionals presume that forests offer health benefits,and is cross-sectional cooperation conceivable?

In high-income countries depression and cardiovascular diseases were predicted to be the two leading causes of DALYs in the year 2030. Private-life stress fosters both kinds of diseases. Scientific findings already show that forest exposure has stress-reducing effects. Particularly in Japan, people have practiced forest bathing to improve their health. The German population also has a strong connection to its forests, and forest law allows forest access, regardless of ownership structure. Hence, the question arises of whether forest exposure could be used in Germany as a kind of stress-coping strategy. To a certain degree, the success of such a strategy in Germany would require the participation of the stakeholders that are active in both the health and the forestry sectors. Therefore, it seems necessary to gain insight into German forest and health professionals' understanding and attitude concerning forest-related health benefits. For this reason, in this pilot study, guideline interviews with professionals of both sectors and with professionals standing in between these professions were conducted, recorded and transcribed. On the one hand, each professional’s presumptions regarding the health-fostering effects of forests were investigated, derived from their subjective certainty that forest exposure has health-fostering effects. In addition, a thought experiment was used to estimate the level of willingness to cooperate with each other in order to motivate people to be physically active in forests. For analysis, Mayring’s qualitative content analysis and a frequency analysis (MaxQDA) were applied. Findings show that most of the interviewed professionals presume forests to have health-fostering effects. Furthermore, something derived from the statements within the context of the thought experiment was that most professionals seem to be willing to cooperate with the other sector. Hence, it might be conceivable that forest exposure may be part of a German stress-coping strategy.     

In situ net N transformations in pine,fir, and oak stands of different ages on acid sandy soil, 3 years after liming

Summary The effect of liming on in-situ N transformations was studied in two stands of different ages of each of Scots pine (Pinus sylvestris L.), Douglas fir [Pseudotsuga menziesii (Mirb.) Franco], and common oak (Quercus robur L.). The stands were located on acid sandy soils in an area with high atmospheric N input. The organic matter of the upper 10-cm layer of the soil, including the forest floor, had a relatively high N content (C: N ratio <25) in all stands. Using a sequential core technique, N transformations were measured in both control plots and plots that had been limed 3 years previously with 3 t ha^-1 of dolomitic lime. Limed plots had a higher net NO _inf3 ^sup- production and a higher potential for NO _inf3 ^sup- leaching than the controls in all stands except that of the younger oak. Net N mineralization did not differ significantly between limed and control plots in oak stands and younger coniferous stands but was significantly lower in the limed plots of the older coniferous stands. It is concluded that long-term measurements of net N mineralization in limed forest soils are needed to evaluate the effect of liming with respect to the risk of groundwater pollution.     

The effect of disturbance by Phellinus weirii on decomposition and nutrient mineralization in a Tsuga mertensiana forest

Summary Microbial biomass in the upper 7 cm of soil and needle decomposition on the forest floor were measured seasonally for 10 months in a mountain hemlock (Tsuga mertensiana) old-growth forest and in a regrowth forest after Phellinus weirii, a root-rot pathogen infection, had caused disturbance. The microbial biomass was higher in the old-growth forest soil than in the regrowth forest soil. However, T. mertensiana needle decomposition rates were higher in the regrowth than in the old-growth forest. Total N, Ca, Fe, Cu, and Zn concentrations in needles increased during the 1st year of decomposition in both the old and the regrowth forests, but P, K, Mg, Mn, and B concentrations decreased. N, P, K, Mg, Cu, and Zn concentrations were lower in regrowth than in old-growth decomposing needles. During mineralization, needles in the regrowth forests released more N, P, and K as a result of higher needle decomposition rates. Our results suggest that higher needle decomposition rates increased the mineralization of N, P, and K, which may lead to increased soil fertility and faster tree growth rates in the regrowth forest.     

辽宁省东部山区5种森林植被类型水文生态效益综合评判

利用层次分析与Fuzzy数学相结合方法,对辽宁省东部山区5种森林植被类型水源涵养能力进行了多目标综合评判。首先利用层次分析法确定了评价因子林冠截留、林冠蒸散、枯落物蓄水、土壤容重、非毛管孔隙度、初渗速率、稳渗速率、土壤总蓄水和土壤有效水的权重集为C=(0.0245,0.0051,0.1993,0.0109,0.0762,0.0565,0.2827,0.0573,0.2866),然后利用最大模糊熵原则确定了评价因子的隶属函数,最后利用Fuzzy综合评判得出油松、落叶松、红松、柞木林、杂木林评价结果模糊子集为B=(0.4686,0.3784,0.4145,0.6128,0.4808),结果表明阔叶林水源涵养效益高于针叶林,其中柞木林效益最佳。     

Reciprocal transfer effects on denitrifying community composition and activity at forest and meadow sites in the Cascade Mountains of Oregon

In order to examine the effects of disturbance, vegetation type, and microclimate on denitrification and denitrifier community composition, experimental plots were established at the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon. Soil cores were reciprocally transplanted between meadow and forest and samples were collected after 1 and 2 years. Denitrifying enzyme activity (DEA) was measured using the acetylene block assay and terminal restriction length polymorphism profiles were generated with nosZ primers that target the gene coding for nitrous oxide reductase. Nitrate concentrations, C mineralization, and water content were measured to gain additional insights into soil properties controlling DEA. Meadow soils were significantly higher in DEA than forest soils, and the highest DEA levels were observed in cores transferred from the meadow into the forest. Nitrate concentrations were also different between forest and meadow soils, but did not correlate to DEA. DEA was higher in open versus closed cores, suggesting an association between denitrification and the rhizosphere. Denitrifier communities of undisturbed forest and meadow soils shifted through a 4-year period but remained distinct from each other. Similarly, denitrifier communities clustered by vegetation type of origin regardless of manipulation, suggesting that the overall denitrifier communities are well buffered against environmental changes.     

Management strategies to increase stand structural diversity and enhance biodiversity in coastal rainforests of Alaska

Coastal rainforests of southeast Alaska have relatively simple species composition but complex structures with high diversity of tree ages, sizes and forest canopy layers, and an abundant understory plant community. Wildlife and fisheries resources also play an important role in the ecological functioning of forest and aquatic systems. Clearcutting has greatly altered these forest ecosystems with significant decreases in structural diversity of forest stands and greatly reduced wildlife habitat. This paper synthesizes information on management options in older forests that have never been actively managed, and in younger forests to increase diversity of stand structures and their associated effects on biodiversity. Light to moderate levels of partial cutting in old-growth forests can maintain the original diversity of overstory stand structures and understory plant communities. In younger forests that develop after clearcutting, mixed alder-conifer stands provide more heterogeneous structures and significantly higher understory biomass than in pure conifer forests. Research has shown that red alder increases diversity and abundance of understory plants, and provides forage for deer and small mammals. Results also show a clear linkage between alder and improved invertebrate diversity in aquatic systems. A combination of light partial cutting in older forests along with inclusion of red alder in conifer-dominated forests could provide the greatest amount of diversity and maintain the complex stand structures that are an important component of these forest ecosystems.     

冬春上海市郊外环林带防尘效应的初步研究

对上海市郊外环林带两侧总悬浮颗粒物浓度（简称TSP）和可吸入颗粒物浓度（简称PM10）同步测定表明：林带的防尘效应与风向有关,下风向处的TSP与PM10日均浓度均分别比上风向低19%-44%和39%-61%。林带边粒径分布测定结果表明：下风向处较大粒径颗粒物的相对含量比上风向处小一些;冬季的粒子谱分布呈现较大粒子和较小粒子重量累积百分比较高、中等粒子的重量累积百分比较低的态势;而春季则相反,中等粒子的重量累积百分比较高、较大粒子和较小粒子则比较低。说明冬春不同风向条件下上海市郊的大道旁林带区具有一定的防尘效应。     

林草间作地土壤低吸力段持水性能的初步研究

以庄浪县5种林草间作模式为对象,在田间采用张力计法测定各模式地的低吸力段土壤水分特征曲线,分析各模式地的土壤持水性能,比较不同模式地的比水容量,结果表明,各模式地土壤含水率随吸力变化较快;五种模式不同土层土壤持水力存在明显差异,表层土壤持水力较大,60cm土层土壤持水能力最差。仁用杏+红豆草模式地土壤持水能力和供水能力最强,是最为耐旱模式,油松+紫花苜蓿模式供水能力最差。