西双版纳勐养自然保护区生境格局研究

使用ARC/INFO和ARC/VIEW地理信息系统 ,对以 1 995年 3月的卫星影像图、相关图件及数据为基础的图形数据库进行迭加分析 ,研究了西双版纳勐养自然保护区的生境格局 .结果表明 :1 )生境格局不是所有生态因素图件的简单迭加 ,以年均温和年降水量为主导因素 ,以自然植被为可见指标研制了生境格局 ;2 )确定出 3种生境类型的 2 0个生境个体 :热带季节雨林生境 (2 37.53km2 ,占总面积的 2 1 % )、热带山地雨林生境(1 2 6 .93km2 ,占 1 1 % )和亚热带季风常绿阔叶林生境 (764 .88km2 ,占 68% ) ;3)初步建立了一个山地生境格局的研究体系 :生态小区→生境类型→生境组分 ;4)生境格局研究揭示了保护区 59%的现有重点保护对象 (热带雨林 )不在核心区的现实 ,为保护区功能区调整提供了科学依据 .     

湖南八大公山亮叶水青冈群落物种多样性的研究

群落物种多样性指数以及群落均匀度、丰富度等指标均能较好地反映亮叶水青冈群落的类型划分、群落结构、生境等特性。也能体现出该群落结构组成的特殊性。群落种多度分布说明此群落富集种少、稀疏种多,而且这些种的多度有一定的规律性的特征。通过研究说明物种多样性定量指标对于深入研究森林群落的特性具有重要的意义     

江西武夷山蝶类昆虫区系概貌

本文分析了江西武夷山区的蝶类昆虫的种类、分布、数量结构和区系组成。其１１２种蝶类隶属１１个区系或混合系,区系成分以东洋系为主体,但古北区系成分占有相当的比重,这一结构表明,江西武夷山处于南北种类昆虫交流汇合的重心地段,其位置接近于东洋区系的北缘。     

天水小陇山锐齿栎群落种间关系定量分析

应用联结系数研究种间关系,结果显示：锐齿栎和榛子为正联结,对环境要求相同,锐齿栎和胡枝子为负联结,对环境反应不同,和箭竹联结系数较低,联结不明显。     

南京栖霞山地区黑松,马尾松年轮Pb,Zn含量与降水量的谱分析

南京栖霞山地区黑松、马尾松年轮Ｐｂ、Ｚｎ含量与降水量的谱分析董雅文,潘良宝,钱君龙,黄景苏（中国科学院南京地理与湖泊研究所２１０００８）ＳｐｅｃｔｒａｌＡｎａｌｙｓｉｓｏｆＰｂａｎｄＺｎＣｏｎｔｅｎｔｓｉｎＴｒｅｅＲｉｎｇｓｏｆＢｌａｃｋＰｉｎｅａｎ...     

长白山北坡不同土壤N2O和CH4排放的初步研究

用箱法技术原位测定了长白山北坡不同土壤(苔原土、生草森林土、棕色针叶林土和暗棕色森林土)6-8月间的N₂O和CH₄排放。结果表明,这些土壤既是N₂O的源,又同时是CH₄的汇。N₂O通量变化于6.17-12.33μg·m^-2·h^-3之间(平均9.37μg·m^-2·h^-1),CH₄通量为-85.63—7.58μg·m^-2·h^-1(平均-41.45μg·m^-3·h^-1),并观察到在N₂O排放和CH₄吸收之间有着相互消长关系。实验室培养实验表明,最大反硝化作用活性存在于土壤上层(0-6cm);不同土壤的反硝化作用活性明显不同。山地暗棕色森林土的CH₄吸收作用也主要发生在土壤的上层(0-12cm).     

Novel quantitative indicators to characterize the protective effect of mountain forests against rockfall

Natural hazards are frequent in mountain areas where they regularly cause casualties and damages to human infrastructures. Mountain forests contribute in mitigating these hazards, in particular rockfalls. Assessing the protective effect of a forest against rockfall is a difficult task for both forest managers and rockfall experts. Accurate and simple tools are therefore required to efficiently evaluate the level of protection that results from the presence of forest.This study defines three novel indicators to quantify the protective effect of forests against rockfalls, regarding (1) the reduction of the frequency of rockfalls, (2) the reduction of their maximum intensity, and (3) the combination of the reduction of the frequency and the energy of the rocks. The first two indicators are relevant for rockfall experts whereas the third is mostly interesting for foresters as it summarizes the protective effect of forest. The Rockyfor3D model was adapted and used to simulate rockfalls propagation on 3886 different forest stands located in all the French Alps. The results of the simulations were used to calculate the three indicators for each forest stand. Finally, the relations between the forest structures and compositions and the indicators values were investigated.Our principal result shows that only three forest characteristics are required to accurately predict the indicators and evaluate the protective level of a forest against rockfall. The two first variables correspond to the basal area and the mean diameter at breast height (DBH) of the forest stand which are two parameters commonly used by forest managers. The third characteristic is the length of forest in the maximum slope direction which can be computed with a geographic information system (GIS). The method proposed in this study is easily reproducible and is suitable to evaluate the protective effect of European mountain forests at different scales. At local scale, the proposed indicators can enrich rockfall studies in which forests are usually set aside to simplify the evaluation. Moreover, the indicators may find direct applications with foresters by allowing them to identify the protective level of their forest and consequently to adapt their management. Finally, the indicators are convenient to perform spatial analysis and produce maps of the protective effect of mountain forests that could find many applications in land settlement or evaluation of ecosystem services.     

内蒙古贺兰山某块菌的形态解剖学与分子生物学研究

利用形态解剖学和分子生物学方法,对采自内蒙古贺兰山地区实验样地青海云杉林下的块菌两菌株（菌株a和b）进行分析鉴定。研究发现：（1）两菌株子囊果均为黄褐色,表面光滑,没有明显的疣状突起和棱角。（2）菌株a产孢组织乳白色、致密团状,菌肉组织褐色;球形、棒状子囊呈蜂窝状排布,内含有1～4个带包被的、表面具有突起状纹饰的球型子囊孢子;子囊孢子双层壁,厚约1.7 μｍ,直径约20 μｍ（含纹饰）。（3）菌株b产孢组织有裂隙,松散,子实层内除了具有上述蜂窝状排布的子囊和内部的球型孢子外,还具有“口袋”状子囊,该子囊内含有大量两端尖、外壁光滑、褐色的椭球型孢子。（4）分子生物学进化分析表明,两菌株聚为一支,但属于块菌属的支持率相对较低;推断两菌株可能为中国猪块菌属Choiromyces新记录种。     

Host utilization and seasonal occurrence of Dermacentor

A total of 3,235 Dermacentor variabilis (Say) specimens were collected from birds, mammals, and by dragging vegetation, and 2,683 D. albipictus (Packard) ticks were collected from deer from 1993 to 1996. Peak seasonal occurrence of adult D. variabilis was from May through July with a precipitous decrease in August. Nymphal D. variabilis populations peaked in June. Peak activity of larvae was bimodal, with one activity peak during late summer (September) and a second peak in winter or early spring. The raccoon, Procyon lotor (L.), was the principal host of adults followed by the Virginia opossum, Didelphis virginiana Kerr. Rodents and the eastern cottontail rabbit, Sylvilagus floridanus (J. A. Allen), were the primary hosts of nymphs. The marsh rice rat, Oryzomys palustris (Harlan), was the principal host of larvae followed by the pine vole, Microtus pinetorum (Le Conte), and white-footed mouse, Peromyscus leucopus (Rafinesque). All stages of D. albipictus were found only on white-tailed deer, Odocoileus virginianus (Zimmermann). Numbers of adult and nymphal D. albipictus peaked in November, whereas larvae peaked in September.     

Upper miocene carbonate ramp deposits from the southernmost part of Maiella Nountain (Abruzzo, Central Italy)

Summary The development of carbonate ramp depositional systems in the Neogene of the Mediterranean Region represents a widespread feature so far analysed in several papers. It is striking to note that the evolution of upper Miocene carbonate ramps, characterized by the presence of coralgal bioherms, highlights the events leading to the Messinian salinity crisis. The coralgal bioherms of preevaporite Messinian age exhibit fossil assemblages indicating marine waters with normal salinity, whereas stromatolitic and microbial encrustations underline the deterioration of the environment during the Messinian salinity crisis. Maiella Mountain is a broad carbonate massif located in Abruzzo (Central Italy). The late lower Oligocene-Messinian part of its stratigraphic succession consists of stacked non-tropical carbonate ramp deposits related to third and higher order sequences. The investigations performed in the southernmost portion of the massif allowed to recognize a complete fourth order carbonate depositional sequence on a homoclinal ramp of pre-evaporite Messinian age. The presence of small coralgal patch reefs and overlaying microbial encrustations is significant. A transect exhibits the stratigraphic framework of the area. The data show how local parameters play a notable role in the development of these deposits.