Soil organic matter in European forest floors in relation to stand characteristics and environmental factors

Published data on the quantities of organic matter in the forest floor (SOM_fl) of European forest stands were collated. Studies of SOM_fl were included if the total sampled surface was at least 0.15 m², the surface of a single sample was at least 100 cm², live material was sorted out, and ash or carbon content was determined. Data from 59 forest stands were compared with regard to stand characteristics and environment. Using a single variable, tree genus was most important for the amount of SOM_fl (R ² _adj = 0.34). The amounts in spruce stands (41 × 10³ kg ha^?1) were significantly higher than those in larch, Douglas fir, oak and birch stands (4–11 × 10³ kg ha^?1). The best significant multiple model was genus combined with stand age and basal area (R ² _adj. = 0.72). The importance of litter quantity and quality for differentiating the tree genera is discussed.     

黄土高原半干旱区景观化集水造绿空间网络构建——以甘肃环县为例

在"聚居背景—聚居活动—聚居建设"的景观"三元论"的哲学基础上,风景园林这一综合学科应对黄土高原的人居环境改善产生重要的作用。文章以黄土高原东部半干旱区环县的人居环境为研究对象,从人居角度分析影响集水造绿的各类因素,从降水、坡度、坡向、河流、泉眼等自然因素以及城镇、道路、水库等人工因素的角度评价集水造绿的适宜性;以GIS技术进行数据整理与量化分级,通过综合考量确定集水造绿的优势地带等级,即适宜度分析;识别集水造绿的"节点"与"路径";规划水绿双赢的空间网络。研究证明,在引入适当人为干预的情况下,通过"基底—节点—路径"方式构建的集水造绿优势空间网络能够适应人居环境集水造绿的需求。     

森林在应对气候变化中的作用探讨

指出了二氧化碳等温室气体的排放是造成全球气候变暖的主要原因,而森林在固碳方面具有经济、有效、持久和生态协调性强的特点,在应对气候变化中具有独特的优势。从生态功能、大力发展森林、科学经营等方面探讨了发展森林资源的对策与建议。     

Explaining conifer dominance in Afrotemperate forests: Shade tolerance favours Podocarpus latifolius over angiosperm species

We contrasted the regeneration success of angiosperm canopy species with that of Podocarpus latifolius to test whether this conifer was sufficiently shade tolerant to be favoured on infrequently disturbed and well-shaded sites. Seedling and sapling population structures were measured in several habitats representing a light gradient in warm temperate forest in the Drakenberg mountains of South Africa. The angiosperm-dominated forest was well-shaded (∼5.5% PAR) and lacked ground vegetation. Seedlings of angiosperm canopy species were abundant but the absence of saplings indicated regeneration failure. In contrast, P. latifolius was represented by all size classes beneath the intact canopy indicating continuous regeneration in angiosperm-dominated forest. Angiosperm regeneration was similarly poor in forest gaps, which were dominated by grasses, ferns and vines. P. latifolius entered the advanced regeneration in gaps by establishing in shade before gap formation. The floor of the Podocarpus-dominated forest was less shaded (∼7.5% PAR) than angiosperm-dominated forest and dominated by grass, which suppressed most conifer regeneration. Gaps in Podocarpus forest were more than double the size of gaps in angiosperm forest and dominated by vines and understorey shrubs. There was no clear winner of the angiosperm–conifer contest in Podocarpus forest gaps. Consequently, gaps maintain limited angiosperm diversity in Podocarpus forest. Angiosperm canopy species regenerated continuously in the high light (∼11.5% PAR) thicket environment. Few seedlings of P. latifolius were recorded in the thicket environment. Our findings are consistent with the hypothesis that shaded and infrequently disturbed forest sites favour shade-tolerant conifers over relatively light-demanding angiosperm species. The outcome of the competitive interaction between angiosperm and conifer at the regeneration phase depends on the relative shade-tolerance of associated species.     

三坊七巷小黄楼庭院空间的气候适应性模拟

为探究植被对人体舒适度的影响及庭院在极端季的微气候环境,文章以福州古典园林典型庭院小黄楼东花厅为研究对象,运用ENVI-met建立实际模拟和仅乔木模拟两种方案进行对比研究,并对实际方案进行量化模拟研究。结果表明:1)当乔木覆盖率达40%时,从时间和空间维度,两种方案的PMV值拟合度均较高,此时乔木对人体舒适度有强烈影响;2)夏季9∶00-17∶00,冬季9∶00前、17∶00后游人不宜长时间在室外活动,应适当调整小黄楼这类庭院的开放时间,如延长夏季开放时间;3)应加大对传统庭院与建筑的宣传保护力度,适当开展戏曲、灯展等文教活动,弘扬传统文化;或将庭院景观与灯景结合,提升景观观赏价值。     

减少森林砍伐和退化机制中的碳评估探讨

涉及森林的气候行动能够最直接地降低大气二氧化碳的增长速度, 并可以最低代价赢得在其他工业部门发展减排技术的时间。通过在发展中国家实施REDD+, 能够显著地减少温室气体排放。在监测、报告和核查(MRV)温室气体排放上存在的技术问题, 以及渗漏、额外性和永久性等政策问题, 是REDD+程序中最主要的障碍。为了实现全球气温升高不超过2℃临界点的目标, 需要国际体系和组织、各国政府和私营部门发挥重要的作用, 需要各国加强建设监测、报告、核查森林碳储量的能力, 需要开发和利用地面测量碳储量计算模型和卫星遥感数据判读转化技术。文中介绍了对实现REDD+可能有重大贡献的国际体系和组织的最新动态以及国家级MRV系统的特征, 探讨了实现全球森林碳评估的途径以及卫星数据在森林碳评估中的应用等, 提出了我国在参与REDD+活动中存在的挑战和应该采取的对策。     

林线对气候变化响应的国内研究进展与展望

高山林线作为一种特殊的生态交错带, 由于其对气候变化的高度敏感性, 成为近年来全球气候变化研究的热点之一。国内对林线的研究起步较晚, 林线对气候变化的响应方面的研究特别是定量研究更少。文中讨论林线的概念和界定方法, 综述林线对气候变化响应的国内研究进展, 总结以往研究存在的问题, 并提出未来研究的趋向。     

减少毁林和森林退化引起的排放:一个综述视角的分析

减少因毁林和森林退化引起的温室气体排放(REDD)对控制和减缓全球气候变暖具有重要作用。UNFCCC第11次缔约国会议将REDD议题列入气候谈判议程, 希望REDD成为2012年后承诺期减缓气候变化的重要措施之一。文中在对国际社会关于REDD的谈判进展和指导原则等进行概述的基础上, 探讨了当前国际社会关注的REDD的焦点问题, 分析了这些焦点问题的现状及其可能的发展趋势, 并据此提出讨论和建议。     

欧洲投资银行林业项目评估政策及在中国的应用

2008年以来, 作为我国林业部门"引进来"国际合作战略的新举措, 欧洲投资银行项目开始在内蒙古、江西等省准备和实施。与世界银行等其他主要国际金融组织相比, EIB项目在中国, 尤其是林业部门仍处在探索阶段, 但潜力很大。文中概述EIB项目的背景及其在林业、应对气候变化方面的政策和评估要求, 提出我国林业应用欧洲投资银行贷款项目的对策建议。     

西双版纳香荚兰栽培气候影响因素及适种区区划

根据香荚兰生长发育特性及其对气象条件的要求,和西双版纳的气候资料,综合分析和评价西双版纳香荚兰栽培的有利气象因素和不利气象条件,用模糊数学的理论和方法对西双版纳海拔800m以下各乡镇进行香荚兰宜植度的区划。