红豆树老林分的群落特征

红豆树群落乔木层物种种类相对较少,红豆树、榕冬青、青冈栎、苦槠4个树种在乔木层中占居绝对优势地位,四者是红豆树群落的主要共建种;木荷、朴树、樟树、米槠、广东润楠、南岭黄檀6个树种的重要值分别为4.0、6.1、6.1、3.2、3.1、3.0,在红豆树群落中的生态环境资源的竞争能力相差不大。红豆树在群落中处于乔木上层,为林中霸王木,具有较显著的相对优势度,成林后对光照条件的竞争具有绝对优势。红豆树群落乔木层的垂直层次结构中,上层木为红豆树和米槠,中层木为榕冬青和青冈栎,苦槠、木荷、朴树、樟树、广东润楠、南岭黄檀为下层木。红豆树在群落中的水平层次地位最高,榕冬青、青冈栎、米槠次之。乔木层中处于上层地位的4个树种在灌木层中,其幼树的重要值仍然位居前列,红豆树、青冈栎、苦槠、榕冬青的重要值分别为7.94、5.94、2.57、2.48。可见红豆树群落的自然演替趋势仍然以红豆树、青冈栎、榕冬青、苦槠为主要共生结构,在无干扰状态下红豆树群落能够实现自然更替。     

浅议文化造园

首先分析当前文化造园存在的一些问题,包括漠视园林文化和歪曲传统文化的现象,继而指出文化造园需要了解场地、尊重历史,其发展与丰富依赖于人与风景在时间长轴上的共同作用、不断积淀；最后以南宁孔庙植物景观和贵港龙蝠山庄假山的设计为例,简明阐释了在园林设计过程中如何结合实际、因地制宜,有效传承、发扬中国传统园林植物文化和山水文化.     

Performance of rainy season greengram as influenced by land configuration and phosphorus application

A field experiment was carried out for 2 crop years (July‐October) at the Indian Agricultural Research Institute, New Delhi to study the effect of land configuration and phosphorus levels on the growth and yield of rainy season greengram under limited irrigation facility. The crop sown on 2 meter wide broad bed and furrow (BBF) showed higher growth attributes, nodulation, yield attributes and yield compared to flat bed (FB) sowing. Application of 30 and 60 kg P₂O₅ha_‐1 showed significant increase in growth attributes, nodulation, yield attributes and yield as compared to no phosphorus application. The moisture status in the soil determined the optimum dose of phosphorus needed for greengram. The combination of BBF sowing and application of 60 kg P₂O₅ ha^?1 recorded the highest grain yield among all the combinations of land configuration and phosphorus levels.     

漯河市沙澧河公园植物配置模式应用技术探讨

在漯河市沙澧河公园植物营造过程中,科学筛选适宜品种,充分利用乡土树种,进行合理配置,营造连续性滨河公园园林景观,构建地带性植物群落,既美化了环境,也保证了生态平衡。     

Factors Associated with Grassland Bird Species Richness: The Relative Roles of Grassland Area, Landscape Structure, and Prey

The factors responsible for widespread declines of grassland birds in the United States are not well understood. This study, conducted in the short-grass prairie of eastern Wyoming, was designed to investigate the relationship between variation in habitat amount, landscape heterogeneity, prey resources, and spatial variation in grassland bird species richness. We estimated bird richness over a 5-year period (1994–1998) from 29 Breeding Bird Survey locations. Estimated bird richness was modeled as a function of landscape structure surrounding survey routes using satellite-based imagery (1996) and grasshopper density and richness, a potentially important prey of grassland birds. Model specification progressed from simple to complex explanations for spatial variation in bird richness. An information-theoretic approach was used to rank and select candidate models. Our best model included measurements of habitat amount, habitat arrangement, landscape matrix, and prey diversity. Grassland bird richness was positively associated with grassland habitat; was negatively associated with habitat dispersion; positively associated with edge habitats; negatively associated with landscape matrix attributes that may restrict movement of grassland bird; and positively related to grasshopper richness. Collectively, 62% of the spatial variation in grassland bird richness was accounted for by the model (adj-R² = 0.514). These results suggest that the distribution of grassland bird species is influenced by a complex mixture of factors that include habitat area affects, landscape pattern and composition, and the availability of prey.     

浅谈园林绿地景石设计

鉴于目前普遍的园林景观建设,针对绿地景石布置,从选材、设置理念到布置方式逐一进行了探讨,为绿地景石的布置设计提供参考。     

区域间水权初始配置的流程——以塔里木河流域为例

以塔里木河流域为例,探讨了区域之间的水权配置流程,主要包括水权配置的准备、配置草案的拟定和配置方案的确定3个子程序。配置流程强调透明性、民主性和互动性。民主协商和公众参与有助于配置过程的顺利进行和配置结果的贯彻落实。     

森林培育装备配属过程的控制

森林培育装备配属过程控制是森林培育实施全面质量管理的重要组成部分。配属过程包括策划、信息采集、选型、动力计算和效益分析、设计评审、验证和确认及配属的更改。森林培育装备配属过程控制能够合理有效地利用资金，保证装备质量的可靠性和适用性。     

汕头市中山公园植物种类调查及配置分析

通过对中山公园实地调研,对园林植物种类、生活型、生态型和观赏特性进行了分析与总结,结果表明:中山公园植物总共162种,隶属于69科129属;具有亚热带地域风味以及岭南风情,植物群落布设自然合理,既符合适地适树的科学原则,也具有外来树种与乡土树种相结合等特点;存在有乡土树种种类少,人类活动与行为对植物景观造成的影响较大,公园的养护管理不到位以及特色植物菊花的配置形式简单等问题;因此在探讨植物种类选取的科学性基础上,从科学性、艺术性、生态性等角度出发,提供了一些优化建议。     

空间五杆机构的可动性分析

机构的第2类可动性。是机构分析与综合所要探讨的基本问题之一。本文对一般形式的空间RRRSR五杆机构的可动性进行分析。通过拆开运动副,分析运动轨迹,根据其雅可比矩阵奇异获得各位形分支的边界后,采用拓朴变换原理,讨论得出该机构的装配条件和连架杆的运动情况。为空间多杆机构的第2类可动性分析,提供了一条方便、实用的途径。