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河南大别山秋色叶树种资源及开发利用 总被引：4，自引：0，他引：4
通过对河南大别山区秋色叶树种质资源的调查研究,本区有秋色叶树种27科41属60种及变种,对本区秋色叶树种质资源进行了总体评价,并对9个尚未开发的重要野生种的性状、特征、生态条件、观赏价值进行了描述,提出了开发利用意见。 相似文献
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辽东山区秋色叶树木资源及园林应用 总被引：1，自引：0，他引：1
对辽东山区秋色叶树种资源进行了调查,筛选出41种,分属于22科30属.分析了主要秋色叶树木的生物、生态学特性及园林美学价值,探讨了它们在园林造景中的应用. 相似文献
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对安徽省巢湖市园林彩叶树种资源及其应用状况进行调查，结果表明，巢湖市园林绿化主要应用的彩叶树种共25科33种，其中乔木22种（占66．7％）、灌木10种（30．3％）、藤本1种（3．0％）；园林彩叶树种中大多数的彩叶期集中在3月初至4月底，或10月至12月上旬；出现频率最高的是红叶石楠，约占彩叶树种的95％，出现频率较高的是樟树、日本晚樱、木樨等18种植物，出现频率较低的是枫香、变叶木、鹅掌楸等；依据叶色及观赏期的分布可分为春色叶类、秋色叶类、常色叶类和斑色叶类四类；彩叶树种的应用主要是作为道路绿化中的行道树与彩篱等，以及在小区及附属绿地中的景观配置等。目前存在的问题主要有彩叶树种种类较少、配植不合理及养护管理不到位。针对问题提出“优先开发本地彩叶树种资源，因地适宜加强引种驯化；合理配植，加强养护”的建议。 相似文献
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针对当前园林绿化中乡土树种普遍不被重视的现实,在介绍乡土树种的优势性的基础上,从加大乡土树种优点的宣传力度、保护原有树木和植被、充分挖掘可利用资源、健全乡土树种繁育体系等方面就如何充分开发和利用乡土树种进行探讨。并对广西具有较高潜在开发利用价值的种质资源及其分布进行介绍。 相似文献
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通过对苏州城区古典园林、风景名胜区、主要街道、公园、学校和居民区等45个样地的调查，统计苏州市秋色叶树种的种类，分析其园林应用。结果表明，苏州城区共有秋色叶树种61种，隶属29科42属，其中乔木50种，灌木8种，藤木3种。在配置方式上，以列植、孤植、丛植为主，分析秋色叶树种在古典园林及风景名胜区、公园、道路、居民区、学校等区域的应用情况，提出苏州市秋色叶树种应用存在的问题及解决的措施，以期为苏州市及周边地区秋色叶树种应用提供参考。 相似文献
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常德市秋色叶植物种类调查及园林应用研究 总被引：1，自引：0，他引：1
阐述秋色叶树种的概念,对常德市秋色叶树种进行调查,对其在常德市园林绿地的应用种类、应用类型和应用方式进行总结,并提出常德市秋色叶树种应用建议。 相似文献
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榧树种质资源调查与评价 总被引：9，自引：0，他引：9
榧树(Torreya grandis Fort.ex Lindl)种子是我国特有的著名干果,为了对榧树种质资源进行有效保护和开发利用,采用实地调查、采集标本、室内烤种、成分分析等方法,对浙江、安徽、江西、福建等榧树分布区的种质资源进行了系统研究。结果表明,榧树资源分布不均,仅少数地方资源保存较好;榧树种内性状变异复杂,不同单株间种子的单粒质量、种核单粒质量、出核率、核形指数及营养成分等变异大,存在一些综合性状优良、品质达到或超过香榧的优株;将香榧和榧树中的优良株系、类型分归于7个主要品种和类型。在榧树中应主要收集一些种子具有综合优良性状、特殊性状和有潜在利用价值的单株;香榧则重点在于收集种子高产、稳产、优质和具特殊性状的优株,对古树及古树群也应加以保护。 相似文献
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Mature trees provide a range of ecosystem services in urban landscapes, represent important wildlife habitat, and impact positively on human wellbeing. However, mature trees are perceived as a risk to people and infrastructure and occupy land suitable for development. Trees are slow to reach ecological maturity and thus difficult to replace when removed. In this study, we: (a) quantified native canopy cover retained during residential development using aerial imagery; (b) identified where native trees are/are not retained within residential developments with a focus on mature trees; and (c) evaluated the effectiveness of current legal mechanisms for protecting native trees during residential development. Native canopy cover was reduced by 49% during residential development. Mature trees had the highest probability of retention within residential developments if they occurred within intact remnant vegetation. A lower probability of retention for mature trees was observed in urban green space, and almost no mature trees were retained in other areas within residential developments, such as residential blocks and road verges. Mature trees had greater probability of retention where the jurisdiction offered some legislative protection. The loss of mature trees during residential development could be reduced with a greater focus on avoiding the removal of existing trees during the planning stage rather than offsetting the impacts elsewhere; and by designing green space within residential developments to ensure adequate separation between mature trees and people and infrastructure. 相似文献
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Pecan trees cv. ‘Moneymaker’ and seedling trees growing in Northern Egypt were sprayed with dinitrocresol mineral oil emulsion, to test its effect on male and female flower bud growth, flowering and fruiting. The treatments had a stimulating effect on growth of male and female flower buds. The treated trees flowered from 1 to 3 weeks earlier than the control. Fruit drop was greatly reduced and, consequently, fruit yield was remarkably increased. 相似文献
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Introduced tree species represent a substantial component of urban forests in cities all over the world. Yet there is controversy about the further use of introduced tree species. Many practice orientated publications,research papers and governmental websites in the fields of urban planning, urban forestry, and urban ecology argue for planting native species and avoiding introduced species. Such arguments for native-only species selection are also touted by environmental groups and the media. Consequently the debate has sometimes spiralled away from a sensible and rational platform where invasion risks and biodiversity loss are discussed, to a groundless and unreasonable argument where exotic species are generally considered incapable of providing ecosystem services. From a European perspective, we here aim to curate a set of necessary considerations for current and future discussions on native and non-native plant material in sustainable urban development. Using examples from Northern and Central Europe we illustrate that in some regions the catalogue of native tree species may be too limited to fulfil ecosystem services and resilience in harsh urban environments. A main message from our line of arguments is that we cannot afford to generally exclude non-native tree species from urban greening. If “native-only” approaches become incorporated in regional, national or international policy documents or legislation there is a risk that urban ecosystem resilience will be compromised, particularly in regions with extreme environmental conditions. Since both invasion risks and sizes of native species pools vary conspicuously at regional to continental scales we also argue to adapt urban policies on using non-native trees to regional contexts. 相似文献
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Trees with root systems established well below grade due to deep planting or soil disturbance are common in urban landscapes, yet the long term effects of buried trunks and subsequent remediation strategies, such as root collar excavation are poorly documented. We evaluated the consequences of deep planting over a 10-year period on tree growth and stability, with and without root collar excavation, for red maple [Acer rubrum L. Red Sunset® (‘Franksred’)] and Northern red oak (Quercus rubra L.) planted at grade or 30-cm below grade. Sleeves to prevent soil-trunk contact were installed around trunks on a subset of deep trees. Root collar excavations were made during the 6th growing season for both species and trees were grown for an additional 4 and 3 growing seasons for red maples and Northern red oaks, respectively. Within two weeks of root collar excavations, pulling tests compared the effect of treatments on stability of red maples. Deep planting generally slowed growth of red maple but had no clear effect on Northern red oak. Root collar excavation had no lasting effect on growth of either species. Approximately 55% of deep red maples and 33% of deep Northern red oaks had roots crossing and in intimate contact with buried trunks, suggesting a potential for future girdling roots. Approximately 25% of deep maples had substantial adventitious rooting. All deep Northern red oaks had new roots emerging just above the first original structural roots but none were clearly adventitious. Trunk sleeves had no effect on growth for either species. Neither deep planting nor root collar excavation resulted in a loss of tree stability compared to trees planted at grade, although failure patterns varied among treatments. Overall, the biggest long term concern for deep-planted trees is the potential for girdling root formation. 相似文献
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Exotic coniferous trees in forests adjacent to spa towns and in parks within spa towns are increasingly being attacked by outbreak populations of native bark beetles in western Bohemia (Central Europe). In the 12 localities in western Czech Republic the current study, we detected a total of 19 native bark beetle species infesting more than 10 % of exotic tree species in the genera Abies, Picea, Pinus, and Pseudotsuga in 1 year. Several exotic tree species were identified as new hosts for native European bark beetles. We also identified three non-native bark beetles, including Phloeosinus aubei, a species that transmits the pathogens that cause cypress canker disease.The numbers of infested trees in the localities were not correlated with the distance from surrounding bark beetle outbreak sites in commercial forests, because all forests adjacent to spas and all forests in spa towns (i.e., “urban forests”) are close to commercial forests with infested trees. Infestations were greater in spa towns than in the forests adjacent to spa towns. We therefore assume that trees within spa towns will be further attacked due to the increasing abundance of native bark beetles. 相似文献
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行道树绿化是城镇密集区绿化的骨干,反应城市的景观风貌.对行道树结构特征研究分析,可以为今后城镇密集区绿化发展提供有益的指导、建议.现以成都市为例,选取城镇密集区内20条特色街道,参考多度、频度、重要值、常绿落叶树种比及乡土外来树种比等指标,对行道树种类、数量、生长情况进行分析研究.结果表明:成都市城区内行道树树种单一,常绿树过多,乡土树种开发利用不够等,需要进一步优化行道树树种格局,增加生物多样性,丰富城市景观. 相似文献
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How much importance is given to native plants in cities’ treescape? A case study in Fortaleza,Brazil
Marcelo Freire Moro Christian Westerkamp Francisca Soares de Araújo 《Urban Forestry & Urban Greening》2014,13(2):365-374
Even though Brazil is a mega-diverse country, many Brazilian cities prioritize exotic plants in their treescapes. Aiming to evaluate how much the treescape in Fortaleza (the fifth largest city in Brazil) is aligned with the policy of valorization of native biodiversity, we sampled street and backyard trees surrounding one of the few vegetation fragments of the city, which is an area considered a priority for conservation. We used the vegetation fragment's flora as reference to compare the potential number of local native species with the actual number of native species in the treescape of the site. To account how much of the native flora was present in the surrounding treescape, we made an inventory of the trees in streets, squares and backyards around the vegetation and compared with the native flora of the vegetation fragment. We then compared the ratio of native to exotic species and checked how many native species of the fragment were also in the surrounding treescape. Exotics were prevalent in both number of species and number of individuals, comprising 70% of the species and 86% of the individuals of public spaces, and 79% of the species and 78% of the individuals of private spaces. Only 14% of the native species of the vegetation were also represented in the treescape, and, in general, they comprehended only a few individuals. We argue that the city's treescape should be re-evaluated in order to value native plants more. Native plants in the treescape could be used as an environmental education tool to publicize native biodiversity to citizens. 相似文献
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对北京大学校园内银杏树分布及喜鹊营巢情况进行了调查。调查表明:北京大学银杏树的喜鹊营巢率明显低于落叶乔木的喜鹊平均营巢率。建议绿化部门在种植银杏树时,把喜鹊的营巢喜好考虑在内,注意保护校园里的古银杏树,而且配置时应以混植、对植为主。 相似文献