Fire in Chihuahuan Desert grassland: Short-term effects on vegetation, small mammal populations, and faunal pedoturbation     

A. Killgore  E. Jackson  W.G. Whitford   《Journal of Arid Environments》2009,73(11):1029-1034

A prescribed burn resulted in significant decreases in canopy cover of the grasses: Bouteloua eriopoda, Sporobolus flexuosus, and Aristida purpurea. One year post-burn, basal cover of B. eriopoda remained significantly lower in burned patches than in unburned areas but there were no differences in basal cover of the other perennial grasses. Only one species of the 14 summer annual species occurred in both burned and unburned plots. There were six species of spring annuals in burned patches but no spring annuals in the unburned grassland ten months post-burn. Fire killed 100% of the snakeweed shrubs (Gutierrezia sarothrae), 77% of the Ephedra torreyana shrubs, and 36% of the Yucca elata. All mesquite shrubs that were top-killed by fire, resprouted one month post-burn. Fire had no effect on abundance and species richness of rodents. There were fewer wolf spider, Geolycosa spp. burrows in burned areas than in unburned grassland. The area and volume of soil in termite galleries and sheeting were significantly larger in the unburned grassland than in the burned areas.  相似文献   

山东近海牙鲆同工酶的生化遗传分析   总被引：31，自引：6，他引：25  

尤锋  王可玲  相建海  徐成  吴谡琦 《海洋与湖沼》1999,30(2):127-133

１９９６年５月,１９９７年１月、１２月和１９９８年４月在山东青荣成近海采集了１３１尾活牙鲆共７１０个生化样品,采用水平淀粉胶和垂直聚丙烯酰胺凝胶电泳的方法,对牙鲆的２５种同工酶进行了分析。结果检测出ＬＤＨ、ＭＤＨ、ＭＥＰ、ＩＤＨＰ、Ｇ３ＰＤＨ、ＡＫ、ＣＫ、ＡＣＰ、ＰＧＭ、ＳＤＨ、ＡＤＨ、ＣＡＴ、ＳＯＤ、ＧＤＨ和ＧＰＩ等１５处同工酶在牙鲆眼睛、肌肉、心脏、肝脏、胸鳍和肾脏等６种组织或器官听表达情况,  相似文献   

优质速溶的食用羊栖菜粉的研制     

王艳芝  周亦来 《海洋学研究》1999,17(2):51-55

以浙江洞头产的淡干羊栖菜为原料,研制速溶型的食用羊栖菜粉。选择对成品粉的溶解性、色泽和风味影响显著的“脱腥软化工艺”中的３个因数进行正交试验［Ｌ９（３４）］,得出优化后的工艺参数如下：处理液配方为６ｇ／ｋｇ柠檬酸加１ｇ／ｋｇ多聚磷酸盐（以干藻体计）;热处理条件为藻浆在处理液中煮沸后自然冷却。对普通粉和速溶粉的理化性质、感官品质和卫生指标进行了比较,并分别研制了羊栖菜胶囊和即食糊两种新产品。  相似文献   

A New Sauropod, Gongxianosaurus, from the Lower Jurassic of Sichuan, China     

LUO Yaonan Sichuan Bureau of Geology  Mineral Exploration  Development  Chengdu  Sichuan  WANG Changsheng Yuzhou University  Chongqing 《《地质学报》英文版》2000,74(2):132-136

The paper describes an early and primitive sauropod dinosaur, Gongxianosaurus shibeiensis (gen. et sp. nov.), from the Dongyuemiao Member of the Lower Jurassic Ziliujing Formation in Shibei Township, Gongxian County, Sichuan Province, China, which is one of the 5 dinosaur fossils discovered in Gongxian in 1997. Except the skull which is incomplete, the fossils are well preserved. It has some features of both sauropods and prosauropods. It is an intermediate type in the evolution of dinosaurs from prosauropods to sauropods and provides materials for the study of the origin and evolution of the sauropod dinosaur fauna. The discovery of this new sauropod furnishes a way for the stratigraphic correlation between the Early Jurassic Ziliujing Formation in the Sichuan basin and the Lower Jurassic Lufeng Formation in the Central Yunnan basin.  相似文献   

三倍体鲶鱼的性腺发育研究   总被引：6，自引：1，他引：5  

尹洪滨  孙中武  潘伟志  陈海燕 《海洋与湖沼》2000,31(2):123-129

于１９９６年５月１０月在黑龙江省肇东市东发渔场两次对１９９５年５月用静水压休克法人工诱导并在池塘养殖的三倍体鲶鱼以及对照组二体鲶鱼随机取样进行性腺组织解剖和显微观察。结果表明,雄性三倍体鲶鱼的精巢发育与对照组二倍体鲶鱼基本保持在相同的发育水平上,均能完成从精原细胞、初级精母细胞经减数分裂形成精子细胞的过程,但是,三倍体鱼精 壶腹腔中精子细胞手成熟精子都明显少于二倍体鲶鱼,而且尚能见到少量畸形精子。  相似文献   

Investigation of Biosorption Behavior of Methylene Blue on Pleurotus ostreatus (Jacq.) P. Kumm.     

Cemil İslek  Ali Sinağ  Ilgaz Akata 《洁净——土壤、空气、水》2008,36(4):387-392

The effect of varying parameters such as dye concentration, adsorbent dose, pH and temperature on the adsorption capacity of Pleurotus ostreatus is investigated. The commonly available white rot fungus Pleurotus ostreatus is investigated as a viable biomaterial for the biological treatment of synthetic basic methylene blue effluents. The results obtained from the batch experiments reveal the ability of the fungus to remove methylene blue. The performance is dependent on the dye concentration, pH, and fungal biomass. The equilibrium and kinetics of adsorption are investigated and the Langmuir equation is used to fit the equilibrium isotherm. The adsorption isotherm of methylene blue follows only the Langmuir model with a correlation coefficient of ca. 0.96–0.99. The maximum adsorption capacity is ca. 70 mg of dye per g of dry fungus at pH 11, 70 mg L^–1 dye, and 0.1 g L^–1 fungus concentration, respectively. This study demonstrates that the fungus could be used as an effective biosorbent for the treatment of dye‐containing wastewater streams.  相似文献   

四种弧菌对中国对虾的致病性研究   总被引：17，自引：0，他引：17  

李天道  于佳 《海洋湖沼通报》1998,(1):57-64

１９９５年８月－１９９６年４月,采用注射感染、浸浴感染、创伤感染和投喂感染比较溶藻弧菌、副溶血弧菌、鳗弧菌、弗尼斯弧菌及其胞外产物对中国对虾的致病性,测定它们的半致死浓度,观察弧菌感染引起的病理组织变化。结果表明,注射感染中,溶藻弧菌、副溶血弧菌、鳗弧菌和弗尼斯弧菌２４小时的半致死浓度（ＬＤ５０）分别是１．２×１０＾６,６．５×１０＾７,４．０×１０＾８,６．８×１０＾９（ＣＦＵ／ｍｌ）;４８小时  相似文献   

福寿螺入侵中国的扩散动态及潜在分布   总被引：1，自引：0，他引：1  

周宇  袁雪颖  杨子轩  刘雄军  欧阳珊  吴小平 《湖泊科学》2018,30(5):1379-1387

福寿螺(Pomacea spp.)严重破坏了农业生产和生态系统,并且对人类健康形成致命的威胁.其中小管福寿螺(Pomacea canaliculata)是世界100种恶性外来入侵物种之一.通过收集福寿螺分布数据绘制分布动态图,重建福寿螺在我国的扩散动态,明晰福寿螺的扩散方向和扩散速度.扩散过程表明福寿螺在中国南方的分布区将会继续扩大范围,有进一步向北扩散的趋势,扩散速度持续增长,未来可能在南方形成全面入侵格局.使用气候和海拔数据变量构建最大熵模型,预测福寿螺的潜在分布区和影响福寿螺分布的关键环境变量,结果显示:浙江、福建、江西、广东、广西、海南和台湾等省已成为福寿螺的高分布区,其危害十分严重;上海、湖北、湖南、四川、西藏、贵州、重庆和云南为中分布区,但也具有较高的潜在暴发风险.环境变量分析显示:年均温度是影响福寿螺分布的最重要环境变量.受试者工作曲线(ROC)检测了模型预测结果的准确度,AUC平均值为0.97,说明预测结果准确,可信度高.这些结果可为进一步开展福寿螺在我国的扩散趋势预测、建立风险评估体系以及制定有效的防治措施提供依据.  相似文献   

Tidal flow near Mana Island,Cook Strait,New Zealand     

E. Bradford  R. A. Wooding 《新西兰海洋与淡水研究杂志》2013,47(1):31-42

Numerical calculations carried out for tidal flow on a small region of the New Zealand coast near Mana Island (41° 5 S, 174° 47 E) solved a finite difference form of the tidal equations, and assumed that the velocity boundary conditions could be approximated by a modified Kelvin wave formula. The results were exponentially smoothed in time at each step in the calculation to remove spurious modes.

The main results are shown as plots of tidal velocity vectors around Mana Island at equally spaced time intervals over a tidal cycle for one run commencing at low tide. The flow becomes very complex, with eddy shedding occurring in the wake of Mana Island, and a tidal rip developing across the shallow connection between Mana Island and the mainland.  相似文献   

Stability of some New Zealand coastal inlets   总被引：1，自引：1，他引：0  

R. A. Heath 《新西兰海洋与淡水研究杂志》2013,47(4):449-457

The relation of tidal compartments to entrance cross‐sectional areas is examined for 20 coastal inlets. Sixteen inlets conform to a linear relationship, which is consistent with stable entrances the sizes of which are determined by the ability of the tidal flow to transport sediment. Based on this criterion deposition should be taking place at the entrances of the other four inlets: Wellington, Lyttelton, and Akaroa harbours, and Paterson Inlet. Available data confirm this for Wellington and Lyttelton Harbours.  相似文献