Field screening for genetic-based susceptibility to mammalian browsing

Browsing by mammalian herbivores is a major problem in plantation forestry. Seedlings are most vulnerable to browsing during establishment, making protection crucial during this period. Aside from reducing herbivore numbers, browsing can be controlled through the application of tree guards or chemical repellents. These methods are generally short-term options. A promising, potentially longer-term method of reducing browsing damage on plantations is to plant individuals with enhanced natural browse resistance. This requires the development of a rapid, cost-effective means of identifying germplasm with enhanced resistance. Here we present such a screening methodology.We planted Eucalyptus globulus seedlings from 22 different seedlots in randomised blocks along edge rows of six operational plantations. Seedlings were monitored for mammal browsing damage and growth for 2 years. Natural variation between E. globulus seedlots resulted in significant variation in the extent to which they were browsed. Differential browsing was evident just 10 weeks after planting, and caused a significant effect on tree growth after 2 years. Differential browsing was thought to be due to variation in levels of plant secondary metabolites (PSMs). The identification and selective planting of high PSM seedlots in high risk areas could be an effective management tool to reduce browsing in plantation forestry.     

Determination of a common forest life cycle assessment method for biodiversity evaluation

Forest biodiversity is highly linked with the occurrence of certain forest development phases (fdp) within the forest life cycle. Generally, the disintegration phase provides the highest biodiversity. The objective of the study was to test different existing forest life cycle assessment approaches aiming at developing a common reliable fdp assessment method. We tested and compared three approaches to record fdp in beech, mixed beech and spruce forests, in managed and unmanaged forests, and in four different plot sizes ranging from 125 to 2000 m². The main results of the fdp comparison are as follows:

(1)

In approximately two thirds of the cases the three considered methods did not yield a corresponding fdp record.

(2)

Generally, the larger the plot sizes, the larger the average fdp deviation in forest reserves.

(3)

The fdp deviation is stronger in beech or spruce dominated forest reserves than in mixed beech forest reserves.

(4)

Plots of 500 m² show most distinct numbers of microhabitats corresponding to the fdp sequence within the forest life cycle.

(5)

Furthermore, the managed forests mostly show lower fdp deviation than the forest reserves.

One approach resulted in the most differentiated portrayal of the studied forest structures compared to the other two as shown by the facts that, (a) the studied forests are seen to be divided up into more fdp than when applying the other two methods, and that (b) the dominant fdp changed depending on the forest community and plot size reflecting different growth conditions and probabilities to meet large dimensioned trees during records, respectively, and (c) considering the distribution of microhabitats which are crucial for xylobiontic (saproxylic) organisms, this approach resulted in the assumed biodiversity patterns with increasing microhabitat numbers up to the disintegration phase thus it was used as a basis for the creation of an optimized fdp assessment method as a tool for common and standardized use in forest ecology and biodiversity research.     

农林复合模式耗水特征的数值模拟——模型的建立与检验

运用土壤—植物—大气水分传输理论，建立农林复合模式的土壤分层水量平衡模型。主要公式有：土壤蒸发与植被蒸腾、林木与小麦根系吸水、土壤层次间的水分交换及植被冠层截留量等水分要素的计算。模型的求解采用数值计算法，并利用０～２００ｃｍ土壤容积含水量的实测值进行验证。研究表明：可以利用所建立的模型，模拟计算林带与小麦根系吸水量、林带与农田蒸散耗水量、林带影响农田土壤水分范围与程度。     

巴拉圭冬青引种栽培及其开发利用研究

巴拉圭冬青为原产于南美洲的一种常绿树种, 具有降低胆固醇、保护肝脏和心脑血管、刺激中枢神经系统等作用。由其叶子加工成的茶广泛受到当地居民的喜爱, 近年来在美国、欧洲国家的发展也很迅速。文中简要介绍了巴拉圭冬青的形态及生物学特性、分布与原产地概况、世界各地引种栽培及其在食品、饮料、医药方面的传统利用和产业化开发现状, 根据其生物气候参数分析了我国适宜引种区域并展望在我国引种与推广应用前景。     

基于生态足迹的长沙市城市化研究

通过查阅长沙市统计年鉴,搜集相关数据资料,应用生态足迹的方法对城市化水平进行定量计算,把生态足迹中涉及的可耕地、林地、河流水域、草地、建设用地、能源提供地六大类生物生产性土地概括为生物资源消费和能源消费两部分,根据数据资料的获取和实际情况,选取其中22个指标,通过设置均衡因子,进行计算汇总得出长沙市2008—2012年的人均生态足迹;同时将城市化水平分为人口城市化、经济城市化、生活方式城市化、地域景观城市化四个测度,结合长沙市实际,选取其中具有代表性的17个指标,运用城市化测度模型计算得出2008—2012年长沙市的城市化水平,再利用线性回归分析方法对生态足迹与城市化水平进行统计,综合分析得出城市化发展过程中的生态环境动态变化情况以及城市化发展过程中存在的问题,对未来城市化的发展提出合理、有效的建议,以期指导长沙市城市的可持续发展,并为规划决策提供科学依据。     

美丽乡村建设中存在的误区及措施

“美丽乡村”建设已成为中国社会主义新农村建设的代名词,全国各地掀起美丽乡村建设的热潮。文章通过塱边村新农村建设的研究,分析了当前美丽乡村建设中存在的误区,探讨了美丽乡村建设的思路和措施;提出美丽乡村建设必须注重创造高效、安全、健康、舒适、优美的乡村环境,注重乡村生态环境的可持续发展,以及对乡村优美的自然景观重现和原有资源的保护。     

芳香植物资源现状及其开发利用

基于国内外有关芳香植物的研究成果, 概述芳香植物的概念、分类和开发利用现状, 总结影响芳香植物生长、发育及其精油产量和品质的环境因素, 分析温度、光照、营养、植物种植模式等对芳香植物生长、发育的影响及其可能的机理, 介绍芳香植物在环境美化、香化、意境化以及杀菌、空气净化和身心保健等方面的研究成果以及目前国内外芳香植物的主要应用形式.     

滇西北退耕还林后续政策分析及发展对策

滇西北是云南省最为贫困的少数民族聚集地区之一,实行退耕还林政策10多年来取得了巨大的成效,随着退耕还林政策补助陆续到期,部分退耕农户生计将出现困难。对退耕还林后续政策进行分析,认为退耕还林补偿标准与现有物价水平不符,套种的规定过于保守,针对政策上的不足与实施过程中存在的作业设计不够规范、监管不力、档案管理不够规范等问题提出相关对策和建议。     

城镇污水处理厂供配电系统分析

污水处理已成为城市建设中必不可少的环节,所以对相应的配套工程也提出了更高的要求,本文将对污水处理厂的供配电系统进行简要的分析。     

黑龙江省林业采运机械化发展变化及驱动力分析

林业机械化是实现林业现代化的基础,采运机械化是林业机械化的重要组成部分.黑龙江省是我国的重点国有林区和主要木材生产地之一,研究黑龙江省的采运机械化发展对于实现我国林业现代化具有重要意义.以黑龙江省森林工业统计资料为基础,对其采运机械化的发展变化进行分析.采用主成分分析法,在SPSS软件中定量计算,找出采运机械化发展的5个驱动因素,并认为驱动采运机械化发展的直接原因是生产成本等经济因素,而根本原因在于森林资源状况的变化.最后预测,未来几年黑龙江省采运机械化水平不会发生显著变化.