中度火干扰对白桦落叶松混交林土壤理化性质的影响

应用空间代替时间的方法对大兴安岭林区白桦落叶松混交林1982-2007年的中度火烧迹地土壤理化性质变化进行研究.结果表明:火后土壤密度增加,土壤孔隙度和土壤含水率降低,但是变化幅度将随着时间的推移逐渐缩小,并在火烧后第20年将接近火烧前水平;火烧后A层和B层土壤有机质均呈降低趋势,A层的降幅逐渐缩小直到火烧后20年比火烧前水平大幅增加;火后土壤A层和B层全磷含量均呈增加趋势,土壤全氮在A层基本也呈增加趋势,B层随火后时间呈波动变化,无明显规律;土壤有效磷含量变化星先降低后增加的趋势;A层土壤速效钾含量的变化基本呈增加趋势,但随时间增加幅度减小,而B层的变化无规律;A层土壤水解氮含量变化呈增加趋势,而B层的变化则与速效钾在B层的变化相似,无明显规律.此研究旨在找出火烧后随时间的推移土壤理化性质的动态变化规律,为火烧迹地的改造和生态恢复提供科学依据.     

Fire intensity effects on seed germination of native and invasive Eastern deciduous forest understory plants

Low-intensity fires were important for maintaining the structure of Eastern deciduous forests (EDFs) for thousands of years before European settlement of North America, though fire suppression became a standard management practice in the 1930s. More recently, prescribed fires have been reintroduced to EDF habitats to aid in the restoration of native plant diversity, but invasions of non-native species such as Microstegium vimineum (Japanese stiltgrass) may increase prescribed fire intensity and suppress colonization of native species. As fire becomes a more common management tool in these habitats, it is vital to predict fire temperature effects on the native and non-native species present in the system. In this study, we found that prescribed fires in areas invaded by Microstegium can be 250-300 °C hotter than fires in nearby native-dominated areas. We then compared the effects of fire on germination rates of six native and three non-native EDF understory species representing the range of functional groups common in this habitat. We manipulated both fire intensity (temperature and length of exposure) and type of fire effect (direct flame and indirect furnace heat) to generate germination curves and make predictions about potential prescribed fire effects on populations of these species. There were very different responses among species to both direct (flame) and indirect (furnace) heating. Germination of three native species, Lycopus americana (American water horehound), Verbesina alternifolia (wingstem), and Vernonia gigantea (tall ironweed), showed signs of being stimulated by heating at low temperatures, while germination of all non-native species (M. vimineum, Elaeagnus umbellata, and Schedonorus phoenix) were inhibited at these lower intensities. High fire intensity (temperatures above 300 °C) effectively killed most species, though one native species, Senna hebacarpa (American senna) and one non-native species, E. umbellata (autumn olive), were capable of tolerating 500 °C temperatures. We conclude that high-intensity prescribed fires in habitats invaded by Microstegium may reduce seed germination of some non-native species, but may also inhibit the regeneration of native understory species.     

Singular and interactive effects of blowdown, salvage logging, and wildfire in sub-boreal pine systems

The role of disturbance in structuring vegetation is widely recognized; however, we are only beginning to understand the effects of multiple interacting disturbances on ecosystem recovery and development. Of particular interest is the impact of post-disturbance management interventions, particularly in light of the global controversy surrounding the effects of salvage logging on forest ecosystem recovery. Studies of salvage logging impacts have focused on the effects of post-disturbance salvage logging within the context of a single natural disturbance event. There have been no formal evaluations of how these effects may differ when followed in short sequence by a second, high severity natural disturbance. To evaluate the impact of this management practice within the context of multiple disturbances, we examined the structural and woody plant community responses of sub-boreal Pinus banksiana systems to a rapid sequence of disturbances. Specifically, we compared responses to Blowdown (B), Fire (F), Blowdown-Fire, and Blowdown-Salvage-Fire (BSF) and compared these to undisturbed control (C) stands. Comparisons between BF and BSF indicated that the primary effect of salvage logging was a decrease in the abundance of structural legacies, such as downed woody debris and snags. Both of these compound disturbance sequences (BF and BSF), resulted in similar woody plant communities, largely dominated by Populus tremuloides; however, there was greater homogeneity in community composition in salvage logged areas. Areas experiencing solely fire (F stands) were dominated by P. banksiana regeneration, and blowdown areas (B stands) were largely characterized by regeneration from shade tolerant conifer species. Our results suggest that salvage logging impacts on woody plant communities are diminished when followed by a second high severity disturbance; however, impacts on structural legacies persist. Provisions for the retention of snags, downed logs, and surviving trees as part of salvage logging operations will minimize these structural impacts and may allow for greater ecosystem recovery following these disturbance combinations.     

长期处于植被条件下香港土壤中氮的矿化

This research examined nitrogen mineralization in the top 10 cm of soils with a vegetation gradient in Hong Kong at sites where fire has been absent for 0, 1, 3, 6 and 17 years (at the time of the study), and the relationships between N mineralization and successional development of vegetation in the absence of fire. The sites including a newly burnt area (S1), short grassland (S2), tall grassland (S3), mixed tall grassland and shrubland (S4), and woodland (S5) were selected, with the in situ core incubation method used to estimate nitrogen mineralization. Throughout the 60-day incubation in four periods, more nitrogen was mineralized at the S3 and S4 sites, the predominantly grassland sites, which contained the highest levels of soil organic matter (SOM) and total Kjeldahl nitrogen (TKN), than the S1 site, while immobilization occurred at the S2 and S5 sites. Leaching loss decreased with successional development of the vegetation, in the order of S1 > S2 > S3 > S4 > S5. The pattern of nitrogen uptake with ecological succession was less conspicuous, being complicated by the immediate effect of fire and possibly the ability of the woodland species to extract nitrogen from the deeper ground. In the absence of fire for 3 to 6 years, the build-up of SOM and TKN was accompanied by active mineralization, thus paving the way for the invasion of shrub and tree species. A close relationship existed between nitrogen mineralization and ecological succession with this vegetation gradient. Inherent mechanisms to preserve nitrogen in a fire-prone environment including immobilization and uptake and the practical relevance of nitrogen mineralization to reforestation are discussed.     

风水文化在植物景观中的应用研究

从风水文化的视角探讨了植物景观中的阴阳属性、五行学说和象征寓意，并以此为指导，研究了风水文化在植物景观的空间营造、物种配置和主题构建三个方面的应用，提出了尊重植物的生长环境和规律、选择有利于人类生活需要和身心健康的植物、赋予植物思想文化内涵，进而构建宜居的植物景观氛围的建议。     

曲靖市森林火烧防火线技术研究

介绍曲靖市森林防火现状及火烧防火线技术应用概况.阐述森林火烧防火线作业的最佳时期选择、工作程序、人员组织、任务分配、设备配置以及作业程序等.     

被文学史遗忘的奇葩——温庭筠的传奇《华州参军》

《华州参军》是温庭筠小说集《乾(月巽)子》中的一部分,该作通过男女主人公三合三离的爱情故事彰显出反传统的情感至上的情爱观。《华州参军》的情节与结构以及其中蕴含的市民化审美情趣直接影响了宋代话本《碾玉观音》。作为一颗长期蒙尘的明珠—《华州参军》理应引起古代小说特别是唐传奇研究者的关注。     

森林消防车动力性仿真技术研究现状与前景分析

介绍了当前国内外对森林消防车动力性能的研究现状,并对其动力性仿真技术的应用(如MATLAB、CRUISE、ADVISOR、PAST等)进行研究。结果表明,动力性仿真技术在森林消防车的性能研究方面具有良好的应用前景。     

论森林防火的意义与措施

简要论述森林防火的必要性、加大森林防火宣传工作的途径以及做好森林防火工作的具体措施。     

Research and Application of Decision - making System in Mine Fire

主要介绍了矿井火灾决策系统的组成及应用。矿井火灾决策系统能大大节省灾变时期的反应时间，为企业在第一时间采取果断措施尽可能消除或减少火灾损失争取宝贵的时间，对于矿井火灾的防治具有重要的意义。