深圳槭--中国槭树科一新种

描述广东省深圳市马峦山发现的槭树科一新种Acer shenzhenensis R．H．Miao,X．M．Wang et J．S．Liang。该种与亮叶槭Acer lucidum Metc．接近,但本种叶顶端尾状渐尖,叶柄长达3 cm,小脉发育,两面网脉清楚,果翅直立,两翅宽1．2-1．5 cm,翅内弯,相叠,易与后者区别。     

湘中红壤丘陵区景观格局变化研究

湘中红壤丘陵区是中国非常脆弱的生态系统之一。在地理信息系统(GIS)和遥感(RS)技术的支持下,以湘中红壤丘陵区的典型区域———长沙市为例,应用景观生态学原理对湘中红壤丘陵区景观格局多样性变化进行了研究。通过对长沙市1986年和2000年的遥感影像资料分析表明,湘中红壤丘陵区现状景观格局以林业景观为主,农田是景观类型中的重要组分;同时由于人类活动的影响,湘中红壤丘陵区景观格局的多样性和破碎化程度逐年明显的增加,景观格局的稳定性逐渐增强。应用马尔柯夫模型对于湘中红壤丘陵区景观格局变化趋势进行了模拟,表明该模型可以应用于湘中红壤丘陵区景观格局的模拟预测中;对长沙市2005~2020年的模拟研究结果表明,由于城市化速度的加快,城镇居民地景观面积将逐年增加。     

吉林西部农牧互动及其引起的生态系统服务价值变化

吉林西部近年来农牧变化频繁,研究其农牧互动及由此引起的生态系统服务价值变化,可以为区域生态环境保护及维持生态功能的可持续性提供科学依据。本文从土地面积、类型及重心变化三方面对吉林西部1954~2000年近50年的农牧用地互动进行了分析,并扩展现有生态系统服务价值的评估方法,对研究区耕地、草地变化中的生态系统服务价值进行了估算。结果表明,1954~2000年,吉林西部耕地增加了3.96×105hm2,草地减少了9.07×105hm2,草地耕地转换频繁,互动比例有所增大;两种用地类型总体重心西移,且变化方向相反。由于耕地单位面积的生态系统服务价值较低,这种变化导致区域生态系统服务价值的整体下降。由农牧业用地变化引起的生态服务价值降低了1.22×108$,其中由低覆盖度草地退化引起的价值降低量占到了71.78%。表明虽然半荒草地的生态服务价值单价不高,但大面积半荒草地的开垦和破坏仍然会对区域总体生态系统服务价值造成不可忽视的影响。     

松阔混交林林分空间结构分析

利用混交度、大小比数和角尺度3种结构参数结合树种组成,分析了松阔混交林林分空间结构。结果表明,优势树种马尾松多呈单种聚集,其余树种中、强度混交占了相当大的比例;马尾松在空间大小对比上占有一定的优势,其余树种则分化严重,既有占优势的树种,也有受压的树种;从林木水平分布格局上看,该地林分是以团状分布为主。     

云南省恙螨名录初报

2000-2004年对云南省寄生恙螨进行现场调查,共采集到恙螨192种,结合其他文献资料报道,目前云南省境内已经发现的恙螨至少有222种,隶属3亚科27属。本文归纳总结了到目前为止云南省所记载恙螨的名称及所寄生宿主。     

云南省小兽体表革螨名录初报

1994年至2004年在云南省境内共调查了25个县（市）,共捕获53种啮齿目、食虫目、攀口目、兔形目和翼手目小兽10803只,从其体表分检出革螨68572只,隶属10科26属80种,其中云南新记录种12种;结合相关文献记载,到目前为止,整个云南省小兽体表革螨共有10科33属112种。     

河南省丛藓科植物新纪录

报道河南省丛藓科植物新纪录4种2变种：尖叶对齿藓芒尖变种(Didymodon constrictus var. flexicuspis (Broth.) Saito),硬叶对齿藓原变种(Didymodon rigidulus var. rigidulus Hedw.),硬叶对齿藓细肋变种(Didymodon rigidulus var. icmadophyllus (Schimp. ex C. Muell.) Zand.),长肋对齿藓(Didymodon longicostata Li),橙色净口藓(Gymnostomum aurantiacum (Mitt.) Jaeg.),硬叶净口藓(Gymnostomum subrigidulum (Broth.) Chen),对这些植物的识别特征、生境和地理分布做了简要讨论,并绘制了形态解剖图。凭证标本存放于河北师范大学植物标本室(HBNU)。     

Study on the Bryoflora in Yunmeng Mountain,south Hebei Province,China

Mountain Yunmeng(37°20'N,113°54'E)is 1520m above sea level and part of the Taihang Mountains.With a temperate continental monsoon climate,the mountain area belongs to the warm temperate deciduous broad-leaved forest region.This thesis was mostly based on the study of more than 2000 packages of bryophytes which were mainly collected by the authors in Mt.Yunmeng.Hebei Province.Of these specimens,there are 36 families,99 genera,and 244 species(including 17 varieties,5 formes,and 1 subspecies)which have been studied and identified.Moreover,it could be seen that Mt.Yunmeng has a diverse population of bryophytes.The bryoflora could be divided into 10 geographical elements:north temperate element make up the majority,accounting for 52.11% of the entire known bryoflora,and another belongs to the East Asian element,accounting for 19.25%.All temperate elements,not including 14 endemic to China and 31 Cosmopolitans,were added up to 188 species,which took 88.3% of all the entire known bryoflora in Mt.Yunmeng.However,there were only 11 Subtropical and Tropical elements.To all appearances,the bryoflora of Mt.Yunmeng showed obvious temperate characteristics.The authors conclude that the bryoflora in Mt.Yunmeng belongs to the middle type,between the warm and dry northern mountain area and the warm and damp southern mountain area.The microclimatic environment greatly influences the bryoflora.     

Long-term modeling of large-scale nutrient cycles in the entire Baltic Sea

Management of eutrophication in marine ecosystems requires a good understanding of nutrient cycles at the appropriate spatial and temporal scales. Here, it is shown that the biogeochemical processes controlling large-scale eutrophication of the Baltic Sea can be described with a fairly aggregated model: simple as necessary Baltic long-term large scale (SANBALTS). This model simulates the dynamics of nitrogen, phosphorus, and silica driven by the external inputs, the major physical transports, and the internal biogeochemical fluxes within the seven major sub-basins. In a long-term hindcast (1970–2003), the model outputs reasonably matched observed concentrations and fluxes. The model is also tested in a scenario where nutrient inputs are reduced to levels that existed over 100 years ago. The simulated response of the Baltic Sea trophic state to this very large reduction is verified by a similar simulation made with a much more complex process-oriented model. Both models indicate that after initial, rather rapid changes the system goes into much slower evolution, and nutrient cycles would not become balanced even after 130 years. Guest editors: J. H. Andersen & D. J. Conley Eutrophication in Coastal Ecosystems: Selected papers from the Second International Symposium on Research and Management of Eutrophication in Coastal Ecosystems, 20–23 June 2006, Nyborg, Denmark     

COASTAL DIATOM‐ENVIRONMENT RELATIONSHIPS IN THE BRACKISH BALTIC SEA1

High‐quality calibration data sets are required when diatom assemblages are used for monitoring ecological change or reconstructing palaeo‐environments. The quality of such data sets can be validated, in addition to other criteria, by the percentage of significant unimodal species responses as a measure of the length of an environmental gradient. This study presents diatom‐environment relationships analyzed from a robust data set of diatom communities living on submerged stones along a 2,000 km long coastline in the Baltic Sea area, including 524 samples taken at 135 sites and covering a salinity gradient from 0.4 to 11.4. Altogether, 487 diatom taxa belonging to 102 genera were recorded. Detrended canonical correspondence analysis showed that salinity was the overriding environmental factor regulating diatom community composition, while exposure to wave action and nutrient concentrations were of secondary importance. Modeling the abundances of the 58 most common diatom taxa yielded significant relationships with salinity for 57 taxa. Twenty‐three taxa showing monotonic responses were species with optimum distributions in freshwater or marine waters. Thirty‐four taxa showing unimodal responses were brackish‐water species with maximum distributions at different salinities. Separate analyses for small (cell biovolume <1,000 μm³) and large (≥1,000 μm³) taxa yielded similar results. In previous studies along shorter salinity gradients, large and small epilithic diatom taxa responded differently. From our large data, we conclude that counts of large diatom taxa alone seem sufficient for indicating salinity changes in coastal environments with high precision.