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31.
Nutrient‐rich biochar produced from animal wastes, such as poultry litter, may increase plant growth and nutrient uptake although the role of direct and indirect mechanisms, such as stimulation of the activity of mycorrhizal fungi and plant infection, remains unclear. The effects of poultry litter biochar in combination with fertilizer on mycorrhizal infection, soil nutrient availability and corn (Zea mays L.) growth were investigated by growing corn in a loam soil in a greenhouse with biochar (0, 5 and 10 Mg/ha) and nitrogen (N) and phosphorus (P) fertilizer (0, half and full rates). Biochar did not affect microbial biomass C or N, mycorrhizal infection, or alkaline phosphomonoesterase activities, but acid phosphomonoesterase activities, water‐soluble P, Mehlich‐3 Mg, plant height, aboveground and root biomass, and root diameter were greater with 10 Mg/ha than with no biochar. Root length, volume, root tips and surface area were greatest in the fully fertilized soil receiving 10 Mg/ha biochar compared to all other treatments. The 10 Mg/ha biochar application may have improved plant access to soil nutrients by promoting plant growth and root structural features, rather than by enhancing mycorrhizal infection rates.  相似文献   
32.
Interactions between two canopy layers in a designed perennial herbaceous plant community were investigated over a period of four and a half years to see whether it was possible to create an urban landscape vegetation that was both flower rich for an extensive time period and resistant to weed colonization at very low levels of maintenance by sowing seed in situ. The ecologically novel plant community involved a tall over-canopy layer of 18 species of North American prairie and woodland edge forbs, and a shade tolerant under-canopy of eight European and North American, mainly woodland forbs. After 5 years the community was dominated by four over-canopy and two winter green under-canopy species. Interspecific competition generated by the sown biomass restricted weed colonization to very low levels, despite the experiment being surrounded by a weedy brownfield. The winter green canopies of the two dominant under-storey forbs closed down gaps within a winter deciduous, prairie-like vegetation, improving winter appearance and providing a major flowering display in spring. This vegetation is an attractive design model for more sustainable herbaceous planting in urban landscape space.  相似文献   
33.
本试验旨在研究饲粮中添加银杏-杜仲叶发酵物(FGEL)对脂多糖(LPS)应激肉仔鸡的生长性能、肠道结构、消化吸收功能和免疫反应的影响,并与未发酵银杏-杜仲叶(GEL)进行比较。采用2×3双因子试验设计,即2种免疫应激处理(腹腔注射LPS或注射等量生理盐水)和3种饲粮处理(基础饲粮及在基础饲粮中添加0.40%GEL或0.40%FGEL的试验饲粮)。选取1日龄健康爱拔益加(AA)肉仔鸡360只,随机分为6个处理,每个处理均设6个重复,每个重复10只鸡。试验期为21 d。在试验第13、15、17、19和21天,3个应激处理的试鸡腹腔注射500μg/kg BW的LPS,其他3个处理注射等量的生理盐水。在试验第21天最后1次注射后2~4 h进行屠宰取样。结果表明:1)与对照饲粮相比,饲粮添加FGEL的肉仔鸡料重比(F/G)有显著改善(P=0.024),饲粮添加FGEL显著缓解了LPS应激肉仔鸡平均日增重(ADG)(P=0.023)和血清D-木糖的含量(P=0.011)的降低。2)与对照饲粮相比,饲粮添加FGEL显著缓解了LPS应激肉仔鸡十二指肠(P=0.011)和空肠(P=0.030)的相对重量...  相似文献   
34.
通过调查广州12条主要道路中央及两侧分车绿化带的树种选择、植物群落配置、景观营造、色彩搭配、绿化功能的合理性等,得出:1)每条道路平均配置5.5种植物,其中乔木2.17种,灌木2.5种,草本0.92种,平均乔灌比0.87;2)配置模式主要是乔木+灌木+地被、乔木+灌木绿篱、乔木+地被和灌木+地被4种形式。  相似文献   
35.
As the impact of green space shrinkage in urban centers becomes obvious, local and regional authorities must adopt environmental planning policies that can help create new green areas to ensure a good quality of life for citizens, along with the rehabilitation of the natural environment. One approach is the promotion of green infrastructure on buildings, including multi-dwelling apartment buildings. In order to effectively promote green infrastructure on buildings, it is essential to comprehend public attitudes toward green infrastructure, so that suitable and effective strategies can be implemented by policy makers. In this study, eight hundred respondents were asked to provide their views on green infrastructure on buildings, on construction that should take place on blocks of apartments in order to accommodate green infrastructure and on the related benefits that may arise from creating green spaces on buildings. A structured questionnaire and stratified sampling were used for the interviews, which were conducted with apartment owners in two regional units of Athens. The results showed that most citizens are willing to proceed with the installation of a green roof, trellis or vertical garden, in order to improve the aesthetics and functionality of the building they live in. Most of the respondents are not familiar with the energy savings that may occur from the installation of a green roof, vertical trellis or garden and wish for a subsidy from the state in order to implement green building solutions. To conclude, the participants in our study are not environmentally aware, since they are not interested in energy conservation but only about the aesthetics of their building; furthermore, they expect to receive financial support from the state in order to make any changes to their home.  相似文献   
36.
为探讨贺兰山野生大型真菌孢子的多样性,2012-2016年在内蒙古贺兰山南寺和哈拉乌沟两地进行取样,每个样地分别由5人从沟谷入口处进行拉网式调查,共获得4 000余份样品,经过微观形态观察和基因ITS序列比对,鉴定出8目25科69属189种大型真菌,主要对其孢子形态特征、表面特征及长宽比进行分析,得到如下结论:质量性状上,孢子形态特征和表面特征相互独立;数量性状上,大小孢子长宽比、孢子极端比和平均比均具有一致性和关联性,显示孢子数量特征的稳定性;菌种间孢子质量性状和数量性状具有很强的多样性;按照孢子多样性低、中、高分类,贺兰山野生大型真菌物种数分别为152种、26种和11种;孢子多样性分类为大型真菌鉴别、分类提供了基本依据。  相似文献   
37.
结合对广州白云山风景名胜区规划和建设的调研和观察结果,从布局、功能、配套设施、生态结构4个方面加以分析,试图总结并归纳城市风景类风景名胜区规划建设的特点和内在规律,为相关风景区规划与建设提供参考。  相似文献   
38.
人的城镇化是新型城镇化的核心。在此分析了"人的城镇化"的内涵、中国在"人的城镇化"中面临的问题,并结合作为全国统筹城乡综合配套改革试验区的重庆市的现状,探寻"人的城镇化"问题的根源。基于重庆市南岸区参与新型城镇化工作试点的实践基础,提出在"人的城镇化"进程中,图书馆全方位知识服务的应对策略。  相似文献   
39.
Urban heat island (UHI) often cause negative impact and has been linked to heart stroke rate, morality, human comfort, energy consumption and air pollution. Fortunately, urban green spaces have been considered as an effective element to mitigate UHI through their cooling effect. However, further empirical research is necessary in order to efficiently guide the design and planning of urban green space. We observed the impacts of urban park's tree, grass and waterbody on microclimate inside the Olympic park of Beijing during summer days. The results indicated that, on average, the park was 0.48–1.12 °C cooler during the day, as well as increased air humidity 2.39–3.74% and reduced human comfort index 1.02–2.43 to generate more comfortable thermal environment. Urban park's cluster trees with short ground vegetation generated higher cooling effect than single trees, grass and waterbodies; proper irrigation regime enhanced the cooling effect of grasses, even the irrigated grass have similar cooling effect with small waterbody on sunny, windless summer days. Therefore, we advise to increase undergrowth coverage and grass irrigation management in order to take advantage of cooling effect of urban parks.  相似文献   
40.
The aim of this study was to quantify street tree population dynamics in the city of Claremont, CA. A repeated measures survey (2000 and 2014) based on a stratified random sampling approach across size classes and for the most abundant 21 species was analyzed to calculate removal, growth, and replacement planting rates. Demographic rates were estimated using a hierarchical Bayesian framework. The community-level (all species) median growth rate was 1.41% per year (95% CI: 1.21–1.65%) with Pinus brutia and Pistacia chinensis growing significantly faster than the community-level median. The community-level median removal rate was 1.03% per year (95% CI: 0.66–1.68%), with no significant differences between species and the community-level medium. Once removed, only 7.2% (95% CI: 4.4–12.9%) were replaced annually. Presence of overhead utility lines influenced tree removal rates while age, diameter-at-breast-height, and prior tree condition influenced tree growth. Overall live aboveground biomass in sampled sites was 713.29 Mg in 2000 and increased to 877.36 Mg by 2014. Biomass gain from growth outweighed loss from removals nearly three-fold; replacement contributed 0.5% of the total biomass gain. We conclude that to increase the resilience of the street tree population will require 1) an increase in percent of full stocking or biomass stock and 2) a shift in the species palette to favor species less vulnerable to pests and expected disturbance from climate change and 3) ongoing monitoring to detect departures from baseline demographic rates.  相似文献   
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