彩叶植物研究进展

彩叶植物是园林植物的重要组成部分。文中就彩叶植物呈色的遗传和生理机理及影响因子、品种选育与引种、繁育方法及其应用途径等作了综述和探讨, 提出今后彩叶植物研究应集中在以下几个方面:彩叶植物的遗传稳定性, 彩叶植物的生理生态特性, 彩叶草本植物的研究与应用, 彩叶风景游憩林的抚育, 彩叶树种的适地适树等。     

林业分工论的经济学基础

本文主要针对“林业分工论的理论依据问题”的争论作了较为详尽的阐述和看法。扼要回顾了“林业分工论”的要点,并对这一理论作了简明叙述,同时着重阐述了“林业分工论”的经济学基础。     

中国林产品对外贸易政策评价初探

首先回顾中国林产品对外贸易政策, 整体上概括当前中国林产品对外贸易政策; 构建对外贸易政策指标评价体系, 根据1998-2008年的林产品贸易数据, 对现有政策的效果进行实证分析评价; 得出结论:中国应将林业作为战略性产业进行扶持, 贸易政策应以国内市场为基础、以扩大出口和提高国际市场份额为目标、以国际市场为导向, 以进口保护促进出口政策, 改变外部经济的贸易政策。     

果树对低温的响应及抗寒评价体系研究进展

低温冷害是果树生产中常见的一种自然灾害,严重影响了果树生产的可持续发展。综述了果树抗寒性的评价、抗寒机制研究和抗寒基因工程研究,提出了该研究领域的前景展望,以期为果树抗寒性研究和抗寒育种提供科学依据。     

绵阳官司河流域水土流失综合报告

报告简述域地质地貌水文气象土壤，植被等地理因素的概况及其与土壤侵蚀的关系，指出本流域由于长防林的建立，发挥了保持水土作用，水土流失不严重，属轻度－中度侵蚀，最大侵蚀模数小于７４００［ｔ／（ｋｍ＾２．年］，全区平均侵蚀模数１７５４．４２［ｔ／ｋｍ＾２．年］；确定了水土流失类型，即片蚀，沟蚀，母质侵蚀三大类；分析了水土流失的原因：以泥岩和灰白砂岩，第四纪冰碛物堆积土侵蚀最高测定不同精植被类型的土壤质地     

银杏雌雄同株调查

一般学者均认为银杏是雌雄异株植物,虽然也有些文献记载“稀为同株”、但缺乏有力的语气年代有人曾对被认为是雌雄同株的银杏进行过调查和报道,但对是否自然形成的真正雌雄同株难于定论,１９９５年,作者在山东滕州市采集花粉时发现,在１株２０ａ生银杏的大枝上,雌雄花同步。     

壶瓶枣鲜果枣酒生产工艺初探

以壶瓶枣鲜果为原料,比较了添加不同酵母菌发酵、后发酵过程中是否添加橡木片以及采用不同澄清方式对枣酒品质的影响。结果表明:用安琪果酒酵母发酵,在后发酵过程中添加橡木片,采用硅藻土澄清方式生产的枣酒品质较好。     

中国南方冰雪灾害对森林火灾火发生短期影响分析——以湖南为例

以湖南省为研究区域,分析冰雪后短期内(3月份)卫星热点的空间分布特征、与受害程度的空间关系,森林火灾发生的特点和扑火人员伤亡情况,以及气象因素对火发生的影响.结果表明:处于受害区确认为森林火灾的卫星热点占总数的61.00%.2008年3月份火灾次数和过火面积异常增高,共发生火灾3 097起,过火面积23 227.68 hm2,火灾次数超过1999-2007年3月份火灾次数的总和,且是1999-2007年3月份火灾次数总和的120.65%,3月份平均火灾次数的10.86倍.过火面积是1999-2007年3月份总和的88.40%,3月份平均过火面积的4.69倍.人员伤亡40人,是1999-2007年3月份人员伤亡总和的72.73%,平均伤亡人数的6.56倍.冰雪灾害后,2008年3月火灾次数、过火面积和人员伤亡人数的异常增高已经超出了气温和降水对火发生正常影响的范围.     

Ecology of termites from the genus <Emphasis Type="Italic">Nasutitermes</Emphasis> (Termitidae: Nasutitermitinae) and potential for science-based development of sustainable pest management programs

The genus Nasutitermes is among the most abundant wood-feeding Termitidae and an extremely diverse and heterogeneous group in terms of its biogeography and morphology. Despite the major role of several Nasutitermes species as structural pests, the phylogenetic status of this genus is still unclear, along with a confused taxonomy and species identification remaining difficult. The first aim of this review was thus to gather and discuss studies concerning the taxonomic status of the genus Nasutitermes in order to clarify this crucial point. Then, our goal was to gain new insights into the management of N. corniger, considered to be the most economically detrimental pest of this genus in South America and a Nasutitermes model species, while filtering available information concerning its biology through the prism of termite control, as well as critically examine the existing methods. We indeed strongly believe that increasing our knowledge of this species’ biological strategies is the key to progress in the challenging question of their sustainable management.     

Morphological plasticity and phosphorus uptake mechanisms of hybrid <Emphasis Type="Italic">Eucalyptus</Emphasis> roots under spatially heterogeneous phosphorus stress

In this study, we subjected the root systems of eight Eucalyptus hybrids currently cultivated in southern China to heterogeneous phosphorus stress to provide a scientific basis for the selection of a highly phosphorus-efficient Eucalyptus variety. When the ability of these hybrids to locate phosphorus under different experimental conditions (phosphorus supply in a homogeneous or heterogeneous manner vs. no phosphorus supply) was compared, the main growth characteristics of Eucalyptus, such as plant height, diameter, dry mass, and phosphorus content, significantly improved when the phosphorus supply was increased from no phosphorus or heterogeneous phosphorus (half of the phosphorus amount) to homogeneous phosphorus. Across these three conditions, the growth traits of different Eucalyptus hybrids differed significantly, indicating different adaptabilities of the hybrids to various phosphorus conditions. The growth traits of the aboveground tissues of Eucalyptus under different phosphorus conditions were largely influenced by the morphology of the underground root system. In addition, the root morphology of Eucalyptus under heterogeneous phosphorus treatment suggested that there were two mechanisms for locating nutrients. Eucalyptus hybrids such as Urophylla 3229, Grandis 9, Guanglin 3, 201-2, and Dunn produced more roots proximal to the phosphorus supply; the other hybrids, Urophylla 3216, Grandis 5, and Guanglin 9, relied mainly on the growth of roots opposite the phosphorus supply to obtain adequate nutrients for growth. With these two strategies, a wide range of nutrients was obtained, root distribution was greater, more soil volume was covered, the contact area of the roots with soil phosphorus was increased, and the uptake of phosphorus by the root system was increased. These results demonstrate that Eucalyptus relies on changes to morphological characteristics of the root system to increase accessibility to phosphorus resources.