千年桐苗木生长规律研究

以千年桐1年生播种苗为研究对象,对其苗高、地径的生长规律和苗高、地径与气象因子的关系等进行研究。试验结果表明：Logistic方程可较好地反映1年生千年桐的苗高、地径生长规律;日平均气温是影响苗高生长的主要气象因子,气象因子与地径生长关系不大。     

伊洛河黄河鲤天然产卵场渔业水质评价

2004-2009年5-8月对伊洛河黄河鲤（Cyprinus carpio haematoperus）天然产卵场水体中的TN、TP等营养盐和WT、pH、DO、CODMn、挥发酚、Cu、Zn、Pb、Cd和Hg等理化指标进行了为期6年的连续监测,对该水域水质的年代变化趋势和质量状况进行了研究和综合评价。结果表明,黄河鲤天然...     

一种车辆平顺性虚拟试验方法

探讨了一种车辆平顺性虚拟试验的方法 :利用 Multi Gen Creator工具对二维和三维图形进行绘制编辑 ,形成虚拟试验场的三维图形数据库 ,然后由 Open GVS SDK通过调用图形数据库及对 Open GVS中通道、场景、光照、相机等资源的编程 ,建立了模拟真实环境的虚拟道路试验场。研究表明 ,用 Open GVS SDK软件建立的虚拟试验场环境逼真 ,拟实效果好。在用鼠标、键盘等外部输入工具进行场景控制时 ,响应快、实时性好。该技术与虚拟样机技术相结合 ,可以在计算机上实现车辆的性能试验     

地被植物在佳木斯城市绿化中的应用

地被植物在城市绿化中得到了广泛应用。在介绍佳木斯市自然条件的基础上,总结提出了佳木斯城市绿化中现应用的低矮灌木、宿根花卉、1～2a生草花和少量藤本植物等地被植物达60余种,并对常用的地被植物在城市园林造景、道路绿化、居住小区绿化、专属绿地绿化的现状进行了概述;同时对地被植物的发展前景进行了分析展望。     

浅析福建省滨海城市园林景观及其特色

从自然环境、地域文化、园林植物三方面介绍了福建滨海城市的园林景观资源.从自然景观和人造景观二方面简要介绍了园林景观的分类.从植物、地域文化、历史、自然环境等景观元素入手,浅析了福建省滨海城市园林景观所具有的特色,对城市景观建设中如何体现景观特色有重要的指导意义,.     

不同类型园林植物对环境因子的影响

通过在晴天和阴天2组对比试验,研究了木槿、栾树与杨树3种不同植物群落对环境中空气温度、空气湿度、光照强度、地温4个因子的影响作用.结果表明:在阴天类型中,3种植物群落均能有效地降低气温、地温与光照强度,从而提高空气湿度,且调节效果为:杨树＞栾树＞木槿;在晴天类型中,栾树与杨树群落的调节效果与阴天相似,其中杨树的调节效果大于栾树.此外,每种植物群落在晴天时对环境因子的调节效果大于阴天时的调节效果.     

滨海碱性土壤的综合改良尝试及效果分析

综合运用工程技术改良、化学改良、生物改良的措施在滨海碱性土壤进行绿化尝试,1a后土壤有机质含量从0.32％上升至0.38％,pH从8.2下降至7.5,取得了较为理想的景观效果,并较大幅度地降低了土壤改良的成本.试验区植物配置尝试了少量喜弱酸性土壤的植物并得以成活,说明前期适当的抗性锻炼对后期栽种的存活具有重要的作用.     

Water circulation, groundwater outflow and nutrient dynamics in Mida creek, Kenya

The relationship between physical hydrodynamic processes and nutrients dynamics was investigated in Mida creek, a groundwater influenced mangrovefringed creek in Kenya between March 1996 and May 1997. The research involved spot and timeseries measurement of nitrate–nitrite, ammonia, silicates, phosphates, salinity, temperature, sealevel as well as tidal currents at seven stations located in the front, middle and backwater zones of the creek. Groundwater level as well as total dissolved solids' concentration, salinity, temperature and nutrients' concentration were also measured once every month in shallow wells (watertable<5m) located in the upper region of the creek. Results of the study show that nutrient concentrations vary with the tide and that, though there is no river drainage, they are of the same magnitude as in mangrove creeks with substantial river runoff. The peak concentrations of NH ₄ ⁺ –N (5.45M), NO ₂ –NO ₃ (5.63M), PO ₄ ^3– –P (0.58M) and SiO ₃ ^2– –Si (81.36M) in the creek occurred during flood tide, 2–3h before high waters. The (NO ₂ ^– + NO ₃ ^– )–N concentrations declined rapidly during ebb tide, reaching the minimum levels during low water. Contribution of groundwater seepage to the net nutrients flux (particularly on nitrite–nitrates) is largest in dry seasons. The study shows that groundwater outflow sustains the mangroves during periods of severe salinity stress and nutrients deficiency in dry seasons. This is essentially by limiting salinity increase and by boosting nutrient supply in dry seasons.     

Spatially Explicit Evaluation of Local Extractive Benefits from Mangrove Plantations in Bangladesh

Mangroves worldwide provide a wide range of ecosystem services utilized directly and indirectly by local peoples. Between 1966 and 2001, Bangladesh established approximately 148,000 ha of mangrove plantations in coastal areas within the Barisal and Chittagong Divisions. Though erosion and human encroachment and conversion have removed over two-thirds of these stands, the Forest Department has continued to undertake new plantation activities.

To investigate how and to what degree people directly utilize these mangroves, I conducted 340 household surveys across eight coastal villages located in close proximity to established plantations. The predominant direct use of the mangrove plantations by local rural communities is the extraction of detritus and nonmain stem material (e.g., limbs, leaves) for combustible fuel. This study uses household foraging distances to estimate and map net value densities based on reported market prices of extracted goods. The average extractive value of mangrove plantations is Tk 2,300 ha^?1 yr^?1, ranging among the villages from 300 to Tk 27,400 ha^?1 yr^?1, with values concentrated closer to the village. Cost-benefit analyses suggest that direct use values alone have justified the establishment and management of previously planted stands. However, other indirect values must be taken into account if these areas are to merit additional plantations.     

Diversity and abundance of carabid beetles in short-rotation plantings of sweetgum, maize and switchgrass in Alabama

This study compares assemblages of carabid beetles, potentially important regulators of herbivorous insect pests, in short-rotation plantings of sweetgum (Liquidambar styraciflua L.) with and without grass cover crops, maize (Zea mays L.) and switchgrass (Panicum virgatum L.). A total of 38 species were trapped during the summers of 1996 and 1997. The dominant carabid encountered was Harpalus pensylvanicus Latreille, a widespread omnivorous species; H. pensylvanicus was particularly prevalent in maize plots. Several other commonly encountered species were primarily associated with one plot type. Overall carabid activity was found to be similar in maize and switchgrass plots and much greater than that in sweetgum plots of both cover types. This may be related to the presence of more consistently available dense ground cover in these plots compared to sweetgum plots, a situation favored by most carabids, although both abundance and diversity were similar in sweetgum plots with and without cover. Diversity, as indicated by species richness and dominance levels, was greater in switchgrass than in maize or sweetgum plots, which were similar. This revised version was published online in June 2006 with corrections to the Cover Date.