中国褐腐真菌泊氏孔菌等三属的分类和生态研究

木材腐朽真菌在森林生态系统中起着关键的降解还原作用，是森林生态系统物质循环中不可缺少的重要组成部分。黄孔菌属Auriporia、褐腐干酪属Oligoporus和泊氏孔菌属Postia的种类具有降解木材中的纤维素和半纤维素、造成木材褐色腐朽的功能，而混合于针叶林土壤中的褐腐残余物是针叶林生态系统更新所必不可少的。但以往国内对三属种类的研究并不深入，仅报道了其中约50%的种类，尚有大量新物种和国内新记录种有待于进一步发现；且有关褐腐真菌的生态学研究尚属空白。本论文对中国地区的黄孔菌属、褐腐干酪属和泊氏孔菌属进行分类学和生态学研究，明确这三属在中国的确切种类，发现新种和中国新记录种，并对这三属种类在寄主树木上的演替进行初步探讨。 研究结果表明： 1、中国目前发现黄孔菌属有2个物种，褐腐干酪属有5个物种，泊氏孔菌属有22种，其中包括本次研究发现的3个新种，分别是Postia calcarea、 P. gloeocystidiata和P. subundosa；2个中国新记录种，分别是Postia lateritia和P. persinica。 2、对每个属的种类给出了的检索表。 3、生态演替的结果表明，黄孔菌属、褐腐干酪属和泊氏孔菌属在树木腐烂程度为无皮倒木且没有完全腐朽时生长发生频次和种类数量均为最多，说明这三属大多数种类均为喜阴、腐生。 4、在对寄主树木选择性的研究结果表明，黄孔菌属、褐腐干酪属、泊氏孔菌属的种类主要生长在针叶树木上，有27种，占总数的93%。在29个物种中能生长在云杉属树木上的种类最多，为18种；而阔叶树中最适宜这三属物种生长的树种是桦属，有8种生长在该类寄主树木上。

Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First Chinese National Arctic Research Expedition, from July to September, 1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, N.radiata, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyrna fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricostata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e., Nuculana pernula, N. radiata, Nucula bellotii, Macoma calcarea, M. moesta alaskana, Macoma sp. and Trichotropis coronata. Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.