闽西常绿阔叶林群落特征分析

采用群落生态学的方法对闽西常绿阔叶林植被的1.6 hm2样地调查统计、分析,结果表明,构成闽西常绿阔叶林群落的优势科是樟科、壳斗科、木兰科、紫金牛科和山茶科等;闽西常绿阔叶林群落的植物区系具有明显的热带、亚热带地理性质;闽西常绿阔叶林群落的建群树种多,且部分不同的建群种间可组合构成不同的群丛,群落类型呈现多样化;闽西常绿阔叶林群落的外貌以单叶、革质、全缘和中小型叶为主的常绿中、小高位芽植物组成为特征;闽西常绿阔叶林群落植物在物种组成数量、科属分布区类型和生活型谱以及叶的性质特征等方面具有中亚热带南部向南亚热带过渡的特点。     

洛阳地区园林常绿阔叶树种资源及其应用

为了对洛阳市的生态环境建设提供参考,对洛阳地区常绿阔叶树种进行了实地调查.结果表明,洛阳地区园林中应用的常绿阔叶树种共有58种,其中,乔木9种,灌木39种、藤本4种及竹类6种;野生常绿阔叶树种10余种.并针对应用中存在的问题,提出相应的发展对策.     

常绿植物在杨凌居住区绿地中的应用调查研究

采用样地调查的方法对杨凌居住区绿地中常绿植物的种类组成、栽植类型、生长状况等进行研究,结果显示:杨凌居住区绿地常绿植物共计15科24属32种,其中,常绿乔木11种,多为松柏科,数量占17%,常绿灌木17种,多为阔叶植物,数量占55%;78%的常绿植物生长良好;常绿植物在居住区绿地中多采用孤植、对植、列植、丛植、片植、绿篱的栽植类型。调查中发现,在居住区绿地中存在着常绿植物的应用未做到适地适树、种植密度不够合理、养护管理不到位等问题,为此提出增加常绿植物种类、保持常绿落叶植物适宜比、注重植物生态性、营造有特色的常绿植物景观和重视日常养护管理等建议。     

Influence of Nitrate:Ammonium Ratios on Growth and Elemental Concentration in Two Azalea Cultivars

Abstract

Rooted cuttings of Rhododendron canescens “Brook” and Rhododendron austrinum were grown in sand culture with a modified Hoagland's solution under greenhouse conditions. The effect of varying ammonium:nitrate (NO₃ ^?:NH₄ ⁺) ratios (100:0, 75:25, 50:50, 25:75, 0:100) on growth, chlorophyll content, plant quality, and elemental tissue concentration were determined. With NO₃ ^? as the nitrogen (N) form, both azalea cultivars exhibited less vegetative growth, lower overall plant quality, with leaves showing visual chlorotic symptoms in comparison to plants receiving NH₄ ⁺ as the N‐form. Leachate pH was highest with NO₃ ^? as the predominate N‐form and decreased significantly with each increment of NH₄ ⁺. With both azalea cultivars, N‐form significantly influenced uptake and utilization of essential plant nutrients. Leaf concentrations of N, potassium (K), calcium (Ca), sulfur (S), boron (B), and molybdenum (Mo) were highest with NO₃ ^?‐N. Leaf elemental concentrations of phosphorous (P), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) increased as NH₄ ⁺ supplied more of the N‐ratio. Significant differences in Mg, Mn, and Zn were observed between species. Results from this study show that foliar N concentration is not an accurate indicator of plant growth response. Further investigations are needed to determine if foliarchlorosis and low growth rates observed with NO₃ ^? fed plants due to an Fe deficiency, to low nitrate reductase (NR) activity in the leaves, or to a combination of these factors.     

Comparison of flower color with anthocyanin composition patterns in evergreen azalea

In evergreen azaleas, major anthocyanins were detected from petals of wild species and cultivars by HPLC analysis. Depending on flower color, all samples were divided into three groups: red, purple or white, using the Japan color standard for horticultural plants. The chromatic components a* and b* values of red group samples showed a convergent distribution, whereas those of purple group samples showed a wider distribution. According to the HPLC analysis, red group samples had two to four major anthocyanins, and those of the purple group had two to six major ones. In contrast, no anthocyanins were detected in the white group petals, although anthocyanidins were detected. These results suggest that the anthocyanin constitution of the purple group flowers is more varied than that of the red group flowers, and this wider variety among purple flowers contributes to extending the diversity of flower color in evergreen azalea.     

低温胁迫对四种野生常绿藤本植物抗寒生理指标的影响

以鹰爪枫Holboellia coriacea、南五味子Kadsura japonica、尾叶挪藤Stauntonia obovatifoliola ssp. urophylla、山蒟Piper hancei等4种野生常绿藤本植物为试验材料,通过人工冷冻处理,对叶片的相对电导率、过氧化物酶(POD)活性和游离脯氨酸含量等3个生理指标进行了测定.结果表明:细胞膜透性表现为逐渐上升趋势;而过氧化物酶(POD)活性和游离脯氨酸含量则随着温度的降低呈现出先上升后下降的变化规律,低温下耐寒性强的种类能保持较高的POD活性.4种野生常绿藤本植物的抗寒性具有明显差异,其中以鹰爪枫抗寒能力最强,其次为南五味子和尾叶挪藤,山蒟抗寒能力最差.     

过渡带地区狗牙根草坪交播早熟禾优良组合筛选

为获得适应过渡带地区四季常绿的优质草坪,采用早熟禾的不同品种,同一品种采用三个播种梯度交播,在已成坪的杂交狗牙根草坪上进行试验.结果表明,不同处理的出苗及苗期生长状况、坪用性状和草坪质量有一定的差异,应用模糊数学综合评判法评定不同处理草坪质量,初步确定,采用早熟禾品种自由2号、交播量为20 g·m2的处理,其综合评判值最高,为0.779 5.     

屋顶绿化5种常绿植物的抗旱性研究

为了筛选更多耐粗放管理且抗旱性强的屋顶绿化常绿植物,选取在西安露地广泛应用且须根发达无主根的5种常绿灌木:金叶女贞、金边黄杨、南天竹、海桐、红叶石楠进行干旱胁迫,通过观察植株外部形态特征的变化,并对其叶片的生理指标:相对含水量、细胞质膜透性、叶绿素、丙二醛、脯氨酸的含量进行测定,利用隶属函数值法进行综合评价。结果表明,5种常绿灌木的抗旱性排序依次为金边黄杨＞海桐＞红叶石楠＞金叶女贞＞南天竹,应用于屋顶绿化时,金叶女贞、南天竹应加强灌溉措施。总体而言说明5种常绿灌木基本能适应西安市的气候条件和屋顶环境。     

浙江天童国家森林公园常绿阔叶林生物量研究(Ⅱ)群落生物量及其分配规律

森林生物量测定一直是森林生态系统研究的主要内容,也是地区森林生态系统长期监测所必需的基础性研究。以浙江天童国家森林公园常绿阔叶林为研究对象,于2003年10月份采用收获法(草本层、灌木层)和标准木法(乔木层)相结合的方法,测定了以木荷Schimasuperba,米槠Castanopsis carlesii为优势种的群落地上部分生物量。结果表明:群落地上部分总生物量为(141.0770±17.4298)t.hm-2(平均值±标准差,n=3),其中接近90%集中于乔木层,其他层生物量分配较少。群落及其各层生物量种间分配差异较大,以优势树种木荷和米槠生物量为主,其生物量主要由树干组成,器官分配大小顺序为干>枝>叶。群落萌枝生物量主要集中在灌木层,50%以上由米槠萌枝生物量构成。群落生物量及其分配状况基本体现了以木荷和米槠为优势种的该群落结构特征及常绿阔叶林群落生物量分配特征。表5参15     

广西银荷木林分类的研究

银荷木林是广西亚热带黄壤山地常见的一类常绿阔叶林 .它是在常绿阔叶林遭受破坏后 ,在保护较好的情况下 ,从演替系列群落顺向演替恢复为常绿阔叶林的一个先期类型 ,并向以栲属林木为主的类型变化 .该文对广西银荷木群系作了较详细的研究 ,划分和论述了 1 0个群丛的基本特点和演替趋向 ,可供进一步研究退化生态系统的恢复和重建参考