Light availability influences root carbohydrates, and potentially vigor, in white oak advance regeneration

Oaks (Quercus spp.) are experiencing recurring regeneration failures associated with pervasive mid- and under-story strata of shade tolerant species in intact, undisturbed forests. Where oak regeneration occurs, inadequate vertical height and depleted root carbohydrate stores impede the ability of regenerating oaks to respond when light does become available. A variety of silvicultural techniques have been developed to increase the penetration of diffuse light, enhancing the light environment on the forest floor, and thereby increasing the likelihood of regenerating oaks to successfully respond to increased light transmittance. We measured shoot and root characteristics, and root soluble non-structural carbohydrate concentrations of white oak (Q. alba L.) advance regeneration exposed to enhanced light intensities associated with a mid-story removal and a clearcut, and compared white oak regeneration vigor to untreated controls.

Root diameter and soluble non-structural carbohydrates increased with increasing light availability. Our data suggest that white oak responds to increases in light transmittance by building below-ground biomass and carbohydrates in the root system prior to an above-ground response. Our study shows that white oak regeneration vigor increases with only modest increases in light. In the absence of other pressures, enhancing the light environment to the forest floor should contribute to successful regeneration of this species.     

贵州亚热带地区的野生香花类观赏植物资源

贵州亚热带地区有野生香花类观赏植物23科39属（1亚属）70种（含新分布种和变种）。分布垂直带谱为海拔160－1000m。花色分为白色、黄色、紫色、黄绿色和红色5类。生境类型分为森林湿地型、疏林灌丛型、山坡草地型和附生型，以森林湿地型和疏林灌丛型的种类居多。银钟花、大叶木莲、尖叶木、云川醉鱼草、紫萼、香槐、两粤黄檀、单性木兰、苍白秤钩风和扭肚藤处于濒危状态。     

贵州喀斯特山区农村庭园生态经济发展途径与对策探讨

本文从分析贵州喀斯特山区农村存在的主要生态经济问题出发,论述了贵州喀斯特山区农村庭园生态经济发展的内涵与目标,提出了发展贵州喀斯特山区农村庭园生态经济的途径与对策.     

贵州省生态旅游资源优势及保护

通过对贵州发展生态旅游的丰富资源优势,发展旅游经济对生态资源的利用原则、保护内容的论述,提出了对生态旅游资源持续利用和保护景区人工建筑的观点。     

贵州水土保持林价值计算方法探讨

本文从贵州实际出发，运用经济管理学理论和林木生长发育规律，在系统分析水土保持林价值构成因素以及各因素之间关系的基础上，建立起一个能满足以树种（类型）为单元的水土保持林价值计算模型。在为水土保持林价值的评估、征占、置换、流转、买卖等活动提供计量、计价依据和方法的同时，还为水土保持林所有者和经营者提供了增加效益的方向与技术关键。     

贵州林木良种生产与推广使用策略初探

文中就目前我省林木良种生产及使用情况,分析阐述了贵州省林木良种推广使用的主要问题,对如何加大我省林木良种生产和推广使用力度提出意见和相关策略。     

贵州省退耕还林工程社会经济效益阶段评价研究

通过对水城、黎平、望谟、关岭、麻江、黔西、龙里、习水、开阳、铜仁10个退耕还林工程综合效益监测重点县107个固定样地户主共91户退耕农户进行连续4年的跟踪调查，同时结合10个县面上统计数的分析及其典型县204户退耕农户的典型调查，对监测区退耕还林的经济、社会效益进行了评价：退耕还林工程区环境效益经济值明显提高，水土流失得到有效控制；工程区退耕农户收入增加，粮食总产量稳定；退耕还林促进了农村劳动力的转移。     

山鸡椒上一种新的干基腐朽病

本文报道了我国贵州北部山鸡椒上一种新的干基腐朽病害，其病原菌是粗皮灵芝（Ganoderma tsunodae(Yasuda ex Lloyd)Trott.)。基于本研究采集的标本及日本模式产地的标本，对此病原菌进行了详细描述。该菌主要危害贵州北部的山鸡椒，造成干基白色腐朽，最后导致树林死亡。对病害的症状，造成的危害及病原菌的分布进行了讨论。     

白蜡虫优良种虫及种群性比组成的研究

白蜡虫(Ericerus pela Chavannes)是我国特产资源昆虫,国内产区很多。实验表明各产区繁育白蜡虫的产量与质量差异显著,其中以金沙江下游云、贵、川三省相接壤的白蜡虫产区,繁育的白蜡虫产卵数量多、雄卵比率高、产蜡时间长、产蜡量多,同时蜡虫的产量高,是我国白蜡虫的优良种虫。     

Effects of Parity of Dam and Breeding Date on the Litter Size of Inner Mongolia White Cashmere Goats

The article through the analysis and research to the effects of parity of dam and breeding date on the litter size of Inner Mongolia White cashmere goats,determine the optimal mating time of Inner Mongolia White cashmere goats,in order to improve the efficiency of reproductive.Data used were 1998 to 2013 reproductive performance records collected from the Arbas stock farm in Inner Mongolia,China.The GLM procedure of SAS 9.0 software was used to determine the significant effect of the parity of dam and breeding date,the results showed that the parity of dam and breeding date had significant effect on litter size (P< 0.01).Litter size was the lowest in 1st parity does (1.37),the significantly increase in litter size with advance in parity and decline after six parity;Mating cycles for September 29th to October 16th had the highest litter size (1.76),and the estrous months and estrus peak time mainly concentrated in October,so this stage in production could be used as breeding period of Inner Mongolia White cashmere goats.