马尾松毛虫(Dendrolimus Punctatus Walker)的发生与寄主植物受害程度的关系的初步观察

马尾松毛虫普遍发生在我国华东、华中和华南的丘陵地区。根据作者等1955年在湖南省调查研究结果,感觉到它的发生动态和松林的受害程度有密切关系。巴尔达鲁耶夫(B.O.oapyeB)1955年在苏联动物学杂志第34卷第4期发表的“西伯利亚松毛虫(Dendrolimus sibiricus Tschetw.)的生殖力与食料专门化”一文,就更进一步证实它们之间     

基于LUCC的城市生态安全研究进展

近代工业革命以来特别是二战以后,世界范围内城市化发展迅速,受城市化驱动的土地利用／覆盖变化（Land use／cover change,LUCC）及其环境影响越来越突出,不仅对城市生态安全产生了危胁,甚至在区域和全球尺度上影响生态系统的结构与功能,成为当今地球生态系统平衡与人类社会可持续发展的研究热点。尽管LUCC与城市生态安全态势有密切联系,然而目前研究中对土地利用变化的驱动机制较为侧重,涉及LUCC对城市生态安全影响的研究文献仍很缺乏。从城市生态安全的概念辨析入手,评述了国内外LUCC与城市生态安全响应研究的进展,将相关研究分为两个阶段：即定性和（半）定量研究阶段。指出了现有研究在理论体系与研究方法在指导实践中的不足之处,即：（1）基于LUCC城市尺度的生态安全研究的理论体系尚不成熟,目前的研究多未结合研究区域LUCC的动态特征对城市生态安全状态进行评价,因而也难以应用于指导城市生态建设实践;（2）目前的城市土地利用的生态影响实例研究中仍很缺乏采用数学模型、地理信息系统（GIS）、环境影响评价（EIA）、生态风险评价技术（ERA）及政策仿真等手段进行动态化的、多场景（Multi-Scenarios）模拟分析的综合运用,也缺乏对这些研究方法在实践中的应用的比较研究;（3）缺乏从土地利用动态监测、驱动力机制、生态响应等方面进行区域生态安全演变及调控的综合研究,现实指导意义有限。在上述工作的基础上,探讨了此研究领域未来的发展方向,即：（1）实现不同研究尺度的紧密结合;（2）多种研究方法的集成运用;（3）基于多学科知识体系的评价方法与指标体系的明细化与合理化。     

家蚕人工饲料的研究:饲料理化因素对家蚕摄食和生长的影响

本文研究了人工饲料某些理化因素对蚕儿摄食和生长的影响,从而阐明家蚕生长发育过程中在摄食行为和营养上的特点和变化。 1.试验表明:绿原酸、桑色素、肌醇可增进蚁蚕摄食:β-谷固醇、没食子酸对保证小蚕正常发育甚为重要,绿原酸、桑色素、肌醇也有良好影响;相比之下,上述一些因子对5龄大蚕的作用较小。此外未看到β-谷固醇对蚁蚕的摄食促进效果。 2.大豆粉的醚溶性成份中,含有影响蚁蚕摄食的忌避物质。大豆粉经90%甲醇处理,可以除去某种水溶性因子,有利小蚕生长;对比之下,上列因素对大蚕的损害较小。比较了二种常见防腐剂对家蚕摄食、成长的影响:山梨酸的饲蚕成绩优于丙酸。 3.在本试验基本组成条件下,收蚁、小蚕、大蚕所用饲料的含水率分别以77%、73%、71%左右为宜。实验说明,蚕儿饲育效果还受饲料中具有成形作用组份的影响。 4.调查了饲料pH和蚕儿摄食、成长的关系:以某些适宜的有机酸(如柠檬酸、抗坏血酸)调节饲料的pH在5左右为好。 5.由于不同发育阶段的蚕儿对摄食、成长促进因子的感受性和对忌避因素的耐受性均不相同,从而提出,对蚕儿作全龄饲育,至少应分别设计为收蚁用、1—4龄小蚕用、5龄大蚕用三种饲料。此外,不同品种家蚕对人工饲料适应性的差别,与对饲料理化条件需求的不同也有一定联系。灵活运用上述结果,将有助于改良饲料组成,降低成本和广辟原料来源。     

中国鸟类新记录种——红胸姬鹟(Ficedula parva)（英文）

2007年4-5月间,笔者在中国河北省乐亭县祥云岛林场及香港特别行政区蒲台岛分别记录到红胸姬鹟(Ficedula parva),为中国鸟类物种新记录。红胸姬鹟和F.albicilla原为红喉姬鹟(F.parva)的两个亚种,近年来很多著者依据形态、鸣声、分子等证据,认为两者应为在古北界异域分布(allopatric)的对种(semispecies)。本文亦就两者的鉴定特征和野外辨识要点进行了讨论。     

A new species of Everhartia associated with leaf spots of Phoenix hanceana from Hong Kong

A new species of Everhartia, E. phoenicis , is described and illustrated. The fungus was collected on living leaves of Phoenix hanceana in Twisk, Tai Mo Shan. Hong Kong. Everhartia phoenicis is associated with yellow spots on living leaves and rachides of the host, and is the only species in the genus known to be pathogenic. It differs from other species of Everhartia in producing symmetric, hyaline, aseptate, horseshoe-shaped conidia. Everhartia phoenicis is compared with other species in the genus. Everhartia is very similar to Delortia and the differences between these two genera are discussed. Two species of Everhartia, E. aquatica and E. tumidoapuis arc transferred from Delortia .     

Effects of Diurnal Changes in the Salinity of the Nutrient Solution on the Accumulation of Calcium by Tomato Fruit

Tomato fruit grown in diurnally fluctuating salinities (8 mScm^–1 during the day and 3 mS cm^–1 at night; 8/3mS cm^–1), accumulated the same amount of dry matter andmagnesium (Mg) as those in constant 3 or 8 mS cm^–1, butan intermediate amount of calcium (Ca). Raising the salinityof the nutrient solution by enriching with macronutrients orby adding NaCl had similar effects. The uptake of ⁴⁵Ca by tomato plants during the day was greaterthan at night and was reduced by salinity in both periods. Whilethe uptake of ⁴⁵Ca by 8/3 mS plants at night was similar tothat of 3 mS plants, the daily uptake was less than that in3 and 5.5 mS plants. The Ca content of tomato fruit increased with truss number at3 and 5.5 mS cm^–1 but not at 8/3 and 8 mS cm^–1.Within the same truss, the distal fruit had a lower Ca contentbut higher Mg content than the proximal fruit. The reductionin Ca content of the distal fruit at 8/3 mS cm^–1 was similarto that at 5.5 mS cm^–1. The Ca content of the tissue atthe distal end of the 8/3 mS fruit was lower than that of the5.5 mS fruit. Similarly, the distribution of ⁴⁵Ca to the distalhalf of the detached 8/3 mS fruit was less than that of 5.5mS fruit. A reduced uptake and inadequate distribution of Cato the truss and to the distal end of the 8/3 mS fruit werethe main causes of these differences. Lycopersicon esculentum(Mill.), tomato, fruit, calcium, magnesium, diurnal salinity