合肥市主要城市景观林群落类型及结构研究

研究合肥市区不同功能区景观林组成与结构,共记录102个样方。结果表明:景观林主要组成种有111种,分属45科、81属;主要优势种是香樟、枫杨、水杉、杨树、桂花、石楠等;不同功能区景观林树种相似性系数分别为0.4(公园与居住区)、0.24(高校与居住区)、0.22(公园与高校);林分平均密度560株/hm2,平均基盖度18.83 m2/hm2,平均胸径16.99 cm,平均树高10.13 m,均为正态分布。群落类型可归纳为5个植被型、16个群系及69个群丛,以落叶阔叶型与常绿落叶阔叶混交型为主。建群树种主要有香樟、广玉兰、女贞、雪松、水杉;群落外貌较整齐,树木整体较为健康,景观效果较佳;但层次结构、树种多样性不高,应丰富树种,增加群落的垂直层次,采用近自然经营。       

营造生态园林 注重群落景观——上海市公园绿地植物群落探析

文章运用生态园林景观分类方法对公园绿地植物群落进行分类,详细介绍典型的植物群落,并指出当前存在的问题。本文从上海市100多个公园绿地中,选取具有代表性的上海植物园、延中绿地等14个公园绿地进行群落探析。       

上海市公园绿地群落的“近自然性”初探

文章通过对上海市区内比较有代表性的三座公园绿地:延中绿地、世纪公园和上海植物园的植物群落组成的区系成份的分析对城市绿地公园人工植物群落的"近自然性"进行了尝试性的研究,并运用经典的相似性系数法对结果进行了评估。结果显示,世纪公园的群落组成最接近自然群落,上海植物园次之,延中绿地最差。总体来讲,上海城市公园绿地对于乡土植物的保护和利用尚有待提高。       

上海浦西建成区城市森林树冠覆盖特点及格局

应用ArcGIS判读2012年上海的遥感影像,分析上海浦西外环线内建成区(360 km2)树冠覆盖特征;判读样方218个、面积3 420 hm2,占研究区的9.5%。结果表明,现有树冠覆盖总面积为8 241.82 hm2、树冠覆盖率22.89%。浦西建成区内55所公园的平均覆盖率为53.72%;不同功能区的树冠覆盖率有显著差异,其中公园最高(53.72%),其次是外环林带(50.72%)、一般绿地(34.60%)、校园(24.13%),住宅最低(21.87%)。按树冠覆盖估算,研究区共有乔木810万余株,潜在的树冠覆盖率可达24.56%~25.67%,至少可增植乔木60万株。       

广州部分城区绿地系统结构分析

以广州市区的绿地系统为研究对象,在不同城区选取公园、广场、道路等不同绿地类型,对各样点的不同植物进行盖度、胸径、高度、间距、重要值、物种多样性指数、群落相似系数等数量参数的调查,从生态学和统计学的角度进行分析;发现广州市区的绿地生态系统群落结构还较简单,群落植物种类相对单一,分布也不够合理;在此基础上,对存在的问题提出改进的方法和措施,为广州的城市生态系统优化提供参考。       

扬州古运河风光带绿地群落环境效应

扬州古运河风光带绿地生态环境效应测试表明:绿地树木对空气微尘有着显著的阻挡、截留和吸滞作用,复层林分的滞尘效应优于园路近20个百分点、优于草坪10.7个百分点。绿地群落可较硬质园路区降低噪音约7dB,可较草坪区降低噪音约4dB;林带减弱噪音的效应与林分组成结构有关,一般以阔叶林减噪效果最显著,叶片大而质硬并重叠排列的树种减噪效果较好,低分枝、矮树冠乔木的减噪作用要比高分枝、高树冠的乔木明显。落叶树种的平均固碳释氧量显著高于常绿树种,且常绿乔木的平均固碳释氧能力是落叶乔木的71%、常绿灌木的平均固碳释氧能力是落叶灌木的67%;不同类型树种的平均固碳释氧能力,总体趋势为:落叶灌木 > 落叶乔木 > 常绿乔木 > 常绿灌木。       

上海宝钢生态园林植物群落类型及丰富度

运用群落生态学方法对宝钢生态园林进行植物群落的类型、组成和丰富度调查,并提出模拟地带性植物群落,构建"近自然"群落和林地的建议。       

应用特尔菲法进行抗性树种选择——以唐山市为例

依据唐山市区园林树种普查资料,根据唐山市自然生态环境特点和植被分布规律,对市区内主要绿地类型中现有园林树种进行统计,运用城市生态学、园林美学、植物群落学等相关理论,采用特菲尔法进行分析评价,筛选出一批抗性树种,为绿化植物的应用提供依据。       

林下草坪管理措施

乔、灌、草、花合理配置的植物群落体系已是园林绿化的基本原则,我们应模拟自然生态环境,建植稳定健康的人工植物群落,强调生态系统的多样性。草坪作为绿地的重要组成部分,草坪植物在园林绿地的造景中发挥着重要作用,有着自身独特的生态优势和美学功效,具有独特的开阔性和空间感,不仅可单独做主景,也能与山石、水面、坡地以及园林建筑、乔木、灌木、花卉等密切组合构成各种不同景观。草坪作为重要的绿化模式,如果处在高大乔木的树荫下,由于乔木层枝叶茂密,林下草坪接受的光照较弱,长此以往会出现林下草坪生长发育不良等生理障碍,使林下草坪的整体景观品相不佳,草地群落的抗逆性和稳定性下降。草坪的使用寿命也会相应的缩短,坪草过早衰败而被迫更新,从而会加大绿地的使用成本,绿地的养护管理费用也相应的增加。故而提出林下草坪的日常养护和病虫害防治措施。       

城市绿地空气微生物浓度的变化特征研究

文章通过对北京市元大都遗址公园内不同类型绿地空气微生物浓度变化特征的研究,结果表明:在不同时间段和不同类型绿地,各林地内的细菌浓度、霉菌浓度和放线菌浓度变化幅度较大,且差异显著。       

4个观赏树种对紫外线屏蔽效应的研究

应用地表植被光谱仪测定紫薇、山茱萸、柳叶栎、北美红栎4个观赏树种的光谱日变化特征。结果表明:各树种对太阳总辐射屏蔽效率的日变化呈"增加"的趋势,对UVA辐射、UVB辐射屏蔽效率的日变化呈"增加—降低"的趋势。80%以上的太阳总辐射、UVA辐射、UVB辐射都被屏蔽,4个树种具有良好的屏蔽紫外线辐射的功能;紫薇对太阳总辐射、UVA辐射、UVB辐射屏蔽效率都最高。     

Carbon isotope discrimination and its relationship to drought resistance under field conditions in genotypes of Eucalyptus globulus Labill.

The aim of this study was to investigate the relationship between carbon isotope discrimination (Δ), survival and growth, to determine the value of Δ for screening for yield improvement under drought conditions. Intra-specific variation in carbon isotope discrimination (Δ) was examined in Eucalyptus globulus. Wood samples were collected from 3 to 7 year-old populations from three different field-sites at Huelva (south-western Spain). Differences between study sites were related to the availability of water resulting from soil physical properties. Average carbon isotope discrimination ranged from 16.7 to 18.1‰. There was a 2.2‰ maximum range in Δ values among different trees of the same age. A strong, positive correlation was observed between average carbon isotope discrimination and average tree diameter at breast height (DBH_ob). Average carbon isotope discrimination was also strongly correlated with survival at the Valdeoscuro site (r²=0.95) and with the percentage of failures in neighbouring trees (r²=0.65) at the San Sebastián site. These results suggest a strong effect of availability of water on Δ values. Implications for the use of carbon isotope discrimination in selecting for better adapted genotypes are discussed.     

北京市23种行道树遮荫及UVB屏蔽效果研究

通过测量植物阴影与全光下的照度、温度、UVB辐射强度等值,对北京市道路23种绿化树种遮荫及UVB屏蔽效果进行研究,结果表明,悬铃木、雪松、毛泡桐、国槐、栾树等树种综合遮荫效果较好;雪松、毛泡桐、悬铃木、栾树、国槐等树种UVB屏蔽效果较好。     

Soil nitrogen transformations varied with plant community under Nanchang urban forests in mid-subtropical zone of China

Soil N transformations using the polyvinyl chloride (PVC) closed-top tube in situ incubation method were studied in Nanchang urban forests of the mid-subtropical region of China in different months of 2007. Four plots of 20 m × 20 m were established in four different plant communities that represented typical successional stages of forest development including shrubs, coniferous forest, mixed forest and broad- leaved forest. Average concentrations of soil NH 4 + -N from January to December were not different among the four plant communities. The concentrations of soil NO 3 - -N and mineral N, and the annual rates of ammonification, nitrification and net N-mineralization under the early successional shrub community and coniferous forest were generally lower than that of the late successional mixed and broad-leaved forests (p<0.05). Similar differences among the plant communities were also shown in the relative nitrification index (NH 4 + -N/NO 3 - -N) and relative nitrification intensity (nitrification rate/net N-mineralization rate). The annual net N-mineralization rate was increased from younger to older plant communities, from 15.1 and 41.4 kg·ha -1 ·a -1 under the shrubs and coniferous forest communities to 98.0 and 112.9 kg·ha -1 ·a -1 under the mixed and broad-leaved forests, respectively. Moreover, the high annual nitrification rates (50-70 kg·ha -1 ·a -1 ) and its end product, NO 3 - -N (2.4-3.8 mg·kg -1 ), under older plant communities could increase the potential risk of N loss. Additionally, the temporal patterns of the different soil N variables mentioned above varied with different plant community due to the combined affects of natural biological processes associated withforest maturation and urbanization. Our results indicated that urban for- ests are moving towards a state of "N saturation" (extremely nitrification rate and NO 3 - -N content) as they mature.     

长白山北坡植物群落间物种共有度的海拔梯度变化(英文)

应用梯度格局法在长白山北坡海拔700-2600 m之间每100 m设置一样地，共计20块样地，应用Jaccard指数，对植物群落间物种共有度的海拔梯度变化进行了分析。不同海拔群落间的共有度，无论以哪一层次的植物种来表达，基本都以与其最相邻海拔的群落之间为最高。相邻海拔群落的不同层次物种间的共有度变化存在相似性和相异性；但如相邻海拔的两个群落属于不同植被类型，其共有度则较低。群落间物种共有度的峰值与谷点反映了植被的海拔梯度格局，且灌木种的物种更替在这些地段具有非常明显的规律。在同一海拔差群落间的共有度数值都非常接近，并均随着海拔差的增加呈明显的下降趋势，表明群落各层次物种的构成有很大的相关性。     

辣木油对小鼠抗紫外线损伤的保护作用

研究辣木油对小鼠抗紫外线损伤的保护作用,为开发防晒护肤品提供实验依据。采用中波(UVB 290~320 nm)和长波(UVA 320~400 nm)紫外线照射小鼠背部皮肤及双耳,造成小鼠皮肤及双耳灼伤水肿模型,以皮指数、耳指数、表皮厚度及皮肤组织病理学等指标评价辣木油对该模型的保护作用。结果显示辣木油组小鼠的耳指数、皮指数、表皮厚度均低于模型组且有显著性差异,能明显抑制紫外线射伤所致小鼠皮肤表皮角质化与浸润,抑制真皮层组织病理改变,提示了辣木油具有抗紫外线损伤的功能即防晒功能。     

Plant community responses to a gradient of site preparation intensities in pine plantations in the Coastal Plain of North Carolina

Intensively managed loblolly pine (Pinus taeda) forests are common in the southeastern United States and offer opportunities for conservation of biologic diversity. Within intensively managed landscapes, stand establishment relies on combinations of mechanical and chemical site preparation and herbaceous weed control (HWC) to manage competing vegetation and increase pine production. However, few long-term studies have described relationships between intensity of stand establishment and effects on plant communities. Therefore, we examined effects of 6 treatments that varied in intensity via combinations of mechanical (wide spacing and strip shear or narrow spacing and roller chop) and chemical (application or no application) site preparation treatments with HWC (broadcast or banded) from 1 to 8 years after site preparation on plant communities in loblolly pine plantations (n = 6) in the Coastal Plain of North Carolina, USA. All treatments resulted in abundant and diverse plant communities. Chemical site preparation had short lived (?4 year) effects on the herbaceous community but long-term effects on woody plants and pine cover. Increasing management intensity by including broadcast HWC or roller chop/narrow spacing did not additively reduce woody vegetation cover or species richness. However, broadcast HWC reduced grass, vine, and forb cover in the first year post-treatment. Average Morista community similarity values ranged from 0.69 to 0.89 among treatments and plots receiving the same chemical site preparation contained the most similar plant communities. Banded HWC can be paired with wide spacing to maximize herbaceous plant growth important for many wildlife species, particularly in the first few years after site preparation. Site preparation techniques should be tailored to local site conditions, plant communities, and management objectives.     

三峡地区河岸带植物群落的特征及其分类与排序研究

本文以长江三峡干流河岸植物群落为研究对象,对群落的物种组成、物种多样性进行了分析,并利用TWINSPAN和DCA对植物群落进行等级式划分。结果表明:河岸植物区系组成较为复杂,以温带成分为主,有着较高比率的世界分布成分。灌、草丛群落之间的物种多样性差异不显著,但部分草丛的不同层次间存在较大差异。TWINSPAN 和DCA分析显示,河岸植物群落呈现沿湿度梯度方向的分布格局。图2表3参8。     

原始次生林蜘蛛群落结构研究

1997年7～8月在湖南省永州市千家洞自然保护区进行了不同海拔、不同林分状况下灌丛蜘蛛群落调查,并应用系统聚类和主成分分析研究了蜘蛛群落结构异质性.结果表明：植物层次好,灌木种类丰富的次生林蜘蛛群落结构优于灌木单调的残次林和人工林;在影响原始次生林蜘蛛群落结构的诸因素中,人为干扰的影响作用最大.     

黄河阶地植物群落演替及物种多样性研究

河流不同阶地的地形和形成年代具有较大差异,对该地区的植物群落物种组成、多样性和生产力等群落结构和功能造成很大影响.以流经青藏高原玛曲段黄河的3级阶地为研究对象,调查了不同阶地对高寒草甸植物群落的影响.结果显示:1)3级阶地上的土壤水分状况不同;2)3级阶地上植物群落的物种丰富度、多度、多样性、均匀度都有相似的发展趋势,即第3级阶地＞第2级阶地＞第1级阶地(P＜0.01);3)第1级阶地的植物群落和第2级阶地的植物群落相似性较高,而第1级阶地和第3级阶地之间的植物群落差异性较大;4)第1级阶地和第2级阶地上植物群落的地上生物量没有显著差异,但都比第3级阶地上植物群落的地上生物量小(P＜0.05).