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《林业科学研究》2021,34(4)
[目的 ]研究园林树种叶片滞尘能力与叶表结构及颗粒物特征的关系,为筛选优良园林绿化树种、提高植被的滞尘效应提供科学依据。[方法 ]以杭州市富阳区5个常见园林绿化树种(红花檵木、海桐、红叶石楠、桂花和香樟)为研究对象,分别在工业区、交通区和清洁区进行采样,采用质量差值法测定植物对不同粒径颗粒物的滞留能力,利用扫描电镜及能谱仪观测植物叶表面结构、颗粒物形貌特征及所含元素,分析叶片表面结构、颗粒物形态、粒径大小与植株滞尘能力的相互关系。[结果 ]在工业区中绿化树种对总颗粒物的滞留量大小为:红花檵木(7.36 g·m-2)桂花(6.53 g·m-2)海桐(6.44 g·m-2)红叶石楠(4.28 g·m-2)香樟(2.59 g·m-2),交通区和清洁区也呈现同样的规律。不同功能区绿化树种对PM10的总滞留量达11.34 g·m-2,不同树种的滞留能力依次为红花檵木、海桐、红叶石楠、桂花和香樟。不同功能区内绿化树种对颗粒物的滞留量呈现工业区交通区清洁区的趋势;植物叶片滞留的颗粒物形态可分为规则和不规则两类,常见球形、椭圆形、蓬松状聚合体、链状聚合体、不规则块状、不规则片状等。[结论 ]各功能区内,均以红花檵木的滞尘量最大,香樟的滞尘量最小;叶片滞留颗粒物中粗颗粒物占比大于细颗粒物;叶片滞留的颗粒物多为烟尘集合体和矿物颗粒。 相似文献
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以贵阳市常见园林绿化竹种琴丝竹为研究对象,应用空气气溶胶再发生器(QRJZFSQ-I)分季节测定了不同污染程度的4个地点(城市广场绿地、城市公园绿地、城郊绿地、城郊林区)的琴丝竹叶片对TSP、PM_(10)、PM_(2.5)、PM_1的吸附量,用扫描电镜观察比较了叶片上、下表面微形态,分析不同污染背景的琴丝竹叶片滞尘能力及其季节变化、叶表面微形态与滞尘量的关系。结果表明:不同污染背景下生长的琴丝竹叶片滞尘能力差异明显,依次表现为城市公园绿地城市广场绿地城郊林区城郊绿地;城区郊区。叶片对不同类别颗粒物的滞留能力也存在差异,4种粒径颗粒物的滞留量均表现出城市公园绿地和城郊绿地差异显著,PM_(2.5)和PM_1的滞留量在城市公园绿地与城郊林区也表现出显著差异;琴丝竹叶片滞留不同粒径空气颗粒物的季节变化在不同地点呈现不同的变化趋势:城郊(林区、绿地)季节变化趋势无明显规律,城区(公园绿地和广场绿地)则在冬季最高,春季或夏季最低;琴丝竹叶表面结构粗糙皱褶多,叶片分布条状突起,有深沟槽,被细柔毛,属于滞尘能力较强的树种,可广泛用于园林绿化。 相似文献
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昆明市主要绿化树种叶片滞尘能力的叶表微形态学解释 总被引：1，自引：0，他引：1
【目的】探究树种叶片滞尘能力形成的叶表微形态机制,以期为昆明市园林绿化树种选择提供参考。【方法】以昆明市10个常见绿化树种为研究对象,采集叶片,用KQ5200型数控超声波清洗器蒸馏水冲洗、过滤烘干,万分之一分析天平称滞尘量,LI-3000A型叶面积仪测量叶面积,计算树种单位面积滞尘量与单叶滞尘量。每树种5片叶,每叶片切取4个5 mm×5 mm组织块,2.5%戊二醛溶液固定,0.1 mol·L-1磷酸缓冲液清洗,梯度乙醇脱水,正丁醇固定,E-1010型离子镀膜仪镀膜;采用S-3000N型扫描电镜观察叶表形态结构特征,并分析其对树种叶片滞尘能力的影响。【结果】昆明10个绿化树种的单位面积滞尘量与单叶滞尘量均存在显著差异(P0.05)。单位面积滞尘量大小顺序为:二球悬铃木荷花玉兰红花檵木紫叶李杜鹃高盆樱桃滇朴球花石楠香樟冬青卫矛;单叶滞尘量大小顺序为:荷花玉兰二球悬铃木紫叶李滇朴球花石楠高盆樱桃红花檵木杜鹃香樟冬青卫矛;单位面积滞尘能力强的二球悬铃木、红花檵木和紫叶李叶表粗糙度高、沟壑数量多且起伏大;叶片气孔密度对树种叶片滞尘能力的影响存在阈值效应;保卫细胞面积与叶片单位面积滞尘量及单叶滞尘量均呈极显著的正相关;叶片表皮毛数量与单叶滞尘量显著正相关。【结论】叶表粗糙度、气孔密度、保卫细胞面积、表皮毛密度等微形态学指标是调控这10个绿化树种叶片滞尘能力的重要因素。 相似文献
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【目的】分析贵阳市不同树种的单位叶面积颗粒物吸滞量差异及其时空变化,以期为合理选择高效滞尘绿化树种提供依据。【方法】以14个常见园林树种为研究对象,以贵阳市城市广场、城市公园、城郊绿地和城郊森林4个不同污染背景地点为采样点。在每个采样点各个树种分别选择3株样树(除部分树种在某个采样点无分布外),定期在4个样点同步采集叶样。采用基于风蚀原理的气溶胶再悬浮方法,测定单位叶面积的颗粒物吸滞量(M)。采集叶片,电子扫描显微镜拍摄叶面显微结构影像,利用图像分析软件量化分析叶面气孔、表皮毛、叶面粗糙程度、蜡质覆盖程度等形态结构特征因子。利用通径分析方法分析叶面形态结构特征因子对叶面颗粒物吸滞量的影响程度。【结果】所测乔木和灌木2种生活型间的吸滞量无明显差异;树种间的叶面悬浮总颗粒物(TSP)吸滞量(MTSP)差异显著,各树种M_(TSP)为1.56～11.14μg·cm~(-2),红花檵木最高,雪松较高,桂花、杜鹃、琴丝竹、女贞和白玉兰居中,香樟、红叶石楠、迎春花、樱花、杨梅、栾树和银杏较弱;通径分析表明,叶面粗糙度、表皮毛密度和长度对叶面TSP吸滞量的影响大于其他叶面微形态因子,具有较多和较长表皮毛且相对粗糙的叶面具有较大吸滞量;叶面吸滞的大颗粒(PM_(10～100))和粗颗粒(PM_(2.5～10))质量百分比(97.36%)高于背景空气(80.29%),这说明叶面趋向吸滞较大粒径颗粒物(PM_(10～100)和PM_(2.5～10)),而对细颗粒(PM_(1.0～2.5))和超细颗粒(PM1)吸滞能力较弱;多数树种冬、春季M值大于夏、秋季;同一树种M值表现为市区采样点高于郊区采样点;同在市区时,树木聚集生长的城市公园采样点高于树木散生的城市广场采样点,呈现出"集聚效应"。【结论】树种间的叶面TSP吸滞量差异显著;影响叶面TSP吸滞量的最主要形态结构因子是叶面粗糙度和表皮毛密度;叶面对大颗粒和粗颗粒的吸滞量高于细颗粒和超细颗粒,高污染地点的单位叶面积吸滞量大于低污染地点。以树木叶面形态结构因子为评价指标,可筛选滞尘能力强的树种。14种参试树种中红花檵木、雪松和桂花的叶面颗粒物吸滞量远大于其余树种,可用于缓解大气颗粒物污染。 相似文献
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以潍坊市9种道路绿化树种为研究对象,分析季节、累积时间、道路交通环境对植物叶片滞留颗粒物能力的影响,建立树种综合滞尘效应量化模型,探讨绿化树种的滞尘规律。结果表明:9种道路绿化树种的滞尘能力差异显著,叶片滞尘量随累积时间增加,20 d后增量减慢趋向平缓,拟合了植物叶片单位叶面积滞尘量与累积滞尘时间的二次曲线方程函数;树种滞尘量具有显著的季节效应,变化规律为春季>秋季>夏季,与潍坊市大气颗粒物浓度的季节变化基本一致;树种滞留颗粒物的能力与道路交通环境基本一致,表现为宝通街>潍安路>北海路>樱前街。采用综合指数法分析树种综合滞尘能力,丁香、悬铃木、日本晚樱滞尘能力最强,五角枫滞尘能力最弱,筛选丁香、悬铃木、日本晚樱作为潍坊市道路绿化的骨干树种推广应用。 相似文献
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选择贵阳市不同地点3种木兰科树种为研究对象,应用气溶胶再发生器测定叶片滞尘能力,并用电镜扫描观察比较叶表面微形态,分析其对滞尘能力的影响。结果表明:不同树种叶片表面附着颗粒物能力不同,红花木莲最大,深山含笑次之,白玉兰最低。叶片附着的不同颗粒物PM_(10)、PM_(2.5)占TSP比例分别在40%左右和2%~3%。电镜扫描发现,红花木莲叶表面粗糙,具沟槽、突起、柔毛等结构,气孔密度大滞尘能力较强,白玉兰叶片较光滑、气孔密度较小,滞尘能力弱。生长环境和季节变化对树种的滞尘效应均有一定的影响,市区(河滨公园)滞尘量是郊区(林科院)的1.5倍左右,冬滞尘量最大,而夏季滞尘量最小。 相似文献
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《林业科学》2016,(12)
【目的】比较树木叶片和塑料叶片单位面积滞纳细颗粒物(PM_(2.5))、可吸入颗粒物(PM_(10))、总悬浮颗粒物(TSP)等大气颗粒物的量,从而区分出受树木叶片结构影响的滞尘量(DRLS)和不受叶片结构影响的滞尘量(DULS),为探索城市树木缓解大气颗粒物污染的贡献及优化树种配置提供科学依据。【方法】以北京市常用的6个绿化树种为对象,持续测定4个季度的叶片滞尘动态,以没有降雨影响的10天为1个试验周期,进行本底采样和颗粒物积累采样,并设置光滑塑料叶片(由自摩擦系数为0.04的聚四氟乙烯塑料制成)对照试验模拟DULS,对采集到的供试样本叶片(含树木叶片和塑料叶片)采用洗脱称量粒度分析法(EWPA),测定10天内各树种叶片单位面积滞尘总量、DULS和对不同粒径颗粒物的滞纳量。【结果】1)滞尘能力最强的侧柏单位叶面积总滞尘量为(124.76±19.27)μg·cm~(-2),是滞尘能力最低的元宝枫的2.24倍,其对PM_(2.5)的滞纳量为(16.92±2.61)μg·cm~(-2)。2)DULS占树木叶片滞尘总量的比例仅为19.65%~42.29%,DRLS所占比例为57.71%~80.35%。3)侧柏的DRLS能力最强,占其滞尘总量80.35%;元宝枫的DRLS能力最弱,占其滞尘总量57.71%;供试针叶树种和阔叶树种的DRLS占滞尘总量的百分比均值分别为77.42%和63.96%。4)针叶树滞纳的各粒级颗粒物中,PM_(2.5)占滞尘总量的13.83%±0.19%,粒径大于10μm的颗粒物占56.82%±1.07%;阔叶树滞纳的各粒级颗粒物中,PM_(2.5)占滞尘总量的8.09%±0.94%,粒径大于10μm的颗粒物占70.29%±3.56%。【结论】树木叶片对大气颗粒物的滞纳具有特异性且作用效果极为显著;供试树种中针叶树滞尘能力显著高于阔叶树,针叶树对小粒径颗粒物滞纳能力较强,而阔叶树对大粒径颗粒物滞纳能力较强。本研究证明绿化树种对缓解大气颗粒物污染有贡献,为合理选择缓解大气颗粒物污染的树种提供科学依据。 相似文献
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文章以聊城市徒骇河风景区10种常绿植物群落为研究对象,测定植物群落内的大气颗粒物浓度和叶面积指数、叶表特征等指标,结果表明,10种群落对3种粒径大气颗粒物的吸附作用存在较大差异。刚竹、圆柏对PM2.5和PM10的吸附作用较强,而白皮松、红叶石楠对PM2.5和PM10的吸附作用则较弱;圆柏、广玉兰对TSP吸附作用较强,大叶女贞、红叶石楠对TSP的吸附作用则较弱;叶面积指数和叶表特征对植物群落吸附不同粒径大气颗粒物具有一定的影响。通过观测冬季不同常绿植物群落对不同粒径大气颗粒物的削减作用,以及叶表面特征和群落冠层对其影响,为大气颗粒物污染的治理在植物选择上提供参考。 相似文献
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利用二甲胺和异丙胺在合适的条件下对酚醛树脂进行改性,得到了两类不同的阳离子型酚醛树脂(CPFR).将其与聚氧化乙烯(PEO)组成双元助留体系,应用于脱墨废纸浆抄纸工艺.实验结果表明,该体系能显著提高细小组分的一次留着率,使其达到90 %以上.而影响PEO-CPFR体系效果的因素主要有助留剂的用量、PEO与CPFR的比值、纸料体系的pH值、剪切力等.该体系的最佳应用条件为PEO用量0.02 %～0.04 %,PEO与CPFR的比为1∶6～1∶12,pH值4～9,能耐受剪切力为400～1 000 r/min转速转子的剪切. 相似文献
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In the Pacific Northwest (PNW) region of the contiguous United States, retention of live (green) trees in harvest units is an integral part of forest management practices on federal lands, yet the ecological benefits that result from various levels or patterns of retained trees remain speculative. The Demonstration of Ecosystem Management Options (DEMO) study was established to address these informational gaps. The experimental design consists of six treatments, each 13 ha in size, replicated at six locations (blocks) in western Washington and Oregon. Treatments represent strong contrasts in retention level (15–100% of original basal area) and pattern (trees dispersed vs. aggregated in 1-ha patches) in mature Douglas-fir (Pseudotsuga menziesii) forests. A wide variety of ecological responses and public perceptions of visual quality have been examined; this paper provides a comprehensive review of the short-term (1–7 years) results of these studies. Level of retention had a strong effect on many responses. At 15% retention, regardless of pattern, microclimate, ecological responses, and public perceptions of visual quality did not differ from those measured in the “clearcut” areas of aggregated treatments. In contrast to level of retention, pattern of retention had limited effect on most measures of biological response. Small changes within forest aggregates were balanced by large changes in adjacent harvested areas, thus on average, responses within aggregated treatments were comparable to those in dispersed treatments. Nevertheless, retaining trees in 1-ha aggregates provided several benefits over dispersed retention. Aggregates greatly reduced damage to and mortality of residual trees (particularly at lower levels of retention) and provided short-term refugia for forest organisms sensitive to disturbance or environmental stress (e.g., bryophytes and late-seral herbs). However, aggregates were susceptible to edge effects (e.g., elevated light and temperature), which may compromise their ability to serve as sources for recolonization of adjacent harvested areas. Collectively, our findings suggest that retention levels >15% are needed to effectively retain sensitive plants and animals, ameliorate harsh microclimatic conditions, and gain public acceptance of retention harvests in these forests. A combination of relatively large (≥1 ha) aggregates and dispersed trees at levels considerably greater than current minimum standards in the PNW may be the most effective strategy for sustaining a broad array of forest values in managed stands. 相似文献
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María Vanessa Lencinas Guillermo Martínez PasturEmilce Gallo Juan Manuel Cellini 《Forest Ecology and Management》2011,262(7):1236-1250
Understory plants could can act as indicators of temperate forest sustainability, health and conservation status due to their importance in ecosystem function. Harvesting impacts on understory plant diversity depends on their intensity. Variable retention has been proposed to mitigate the harmful effects of timber harvesting, but its effectiveness remains unknown in southern Patagonian Nothofagus pumilio forests. The objectives of this study were to: (i) define a baseline of understory plant diversity in old-growth forests along a site quality gradient and under canopy gaps; (ii) evaluate stands with three different variable retention treatments compared to old-growth forests; and (iii) assess temporal changes during 4 years after harvesting (YAH). A 61 ha N. pumilio forest was selected. Understory plant (Dicotyledonae, Monocotyledonae and Pteridophyta) richness, cover (including woody debris and bare forest floor) and aboveground dry biomass were characterized in summer for 5 years. Before harvesting, baseline samples were conducted along a site quality gradient and outside/inside canopy gaps. Analyzed treatments include a control of old-growth forest (OGF) and three different harvesting treatments with variable retention: (i) dispersed retention (DR) of 30 m2 ha−1 (20-30% retention); (ii) aggregated retention (AR) with one aggregate per hectare and clear-cuts (28% retention); and (iii) combined dispersed and aggregated retention (DAR) with one aggregate per hectare and dispersed retention of 10-15 m2 ha−1 (40-50% retention). Data analyses included parametric and permutational ANOVAs, multivariate classification and ordinations.Before harvesting, 31 plant species were found, where richness, cover and biomass were directly related to site quality. The presence of canopy gaps did not have a significant impact on the measured variables. After harvesting, 20 new species appeared from adjacent associated environments (two from N. antarctica forests and 18 from grasslands and peatlands). At the stand level, understory values were higher in AR > DR > DAR > OGF. Most (81-95%) plant richness at baseline conditions was conserved in all treatments, where inside the aggregates understory remained similar to OGF. Combination of aggregated and dispersed retention (DAR) better limited exotic species introduction and protected sensitive species, improving conservation in harvested stands. Changes in understory variables were observed after the first YAH in all treatments; greater changes were observed in the harvested areas than in aggregates. Changes stabilized at the fourth YAH. As a conclusion, the location of retention aggregates should be selected to preserve species understory diversity of more speciose and diverse habitats or particularly uncommon stands. Implementation of different kinds (patterns and levels) of retention for improvement of biodiversity conservation in harvested forests should be included in timber and forest management planning. 相似文献
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Guillermo Martínez Pastur María Vanessa Lencinas Juan Manuel Cellini Pablo Luis Peri Rosina Soler Esteban 《Forest Ecology and Management》2009
Forestry practices integrating ecological and social criteria have been replacing those based only on economic values. Traditional silviculture, such as shelterwood cuts (SC), transforms uneven-aged original stands to an even-aged managed forest. Recently, other methods have proposed to conserve some of the original heterogeneity of the old-growth forests. One proposal leaves 30% of the timber quality forest area as aggregated retention and 20% basal area as dispersed retention. The aim of this study was to analyze the feasibility of timber management with aggregated and dispersed retention in Nothofagus pumilio old-growth forests by analyzing timber and harvesting yield potential compared with traditional regeneration systems. Also, remnant tree stability of aggregated retention was analyzed. 相似文献
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The concentration influence of some commercial polyethylenimines, used as retention agents, on the retention efficiency during the sheet formation is studied in this paper. The conditions of an industrial wire end have been simulated by means of a dynamic jar of exclusive design. Measurements of the zeta potential have been taken to quantify the surface charge of particles and the colloid titration ratio (quotient between the cationic demand and the anionic demand of pulp slurries) has been evaluated. Both techniques have proved convenient to monitor the retention level; therefore, they are efficient methods to control the retention level in the sheet formation. The univocal relation existing between zeta potential and the logarithm of the colloid titration ratio has been demonstrated. Finally, the variation of the level of turbulence has proved the importance of the hydrodynamics factors in the retention. 相似文献
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18.
研究了木聚糖碱抽提液超滤过程中截留率的变化规律。研究结果表明：GC5、GC10、G-C30这3种超滤膜对木聚糖截留率均大于90％，操作压力、进料速度、木聚糖浓度等操作参数几乎不影响它们对木聚糖的截留能力；另外，操作压力、进料速度、木聚糖浓度等操作参数增大时，PS6超滤膜对木聚糖的截留率随之略有增大，在76％～87％之间。上述4种超滤膜对木聚糖碱抽提液中非还原糖类固形物的截留率均小于15％。GC5、GC10、GC30、PS6等4种超滤膜适用于纯化木聚糖碱抽提液，但GC类超滤膜更适合于木聚糖碱抽提液的超滤纯化过程。 相似文献
19.
深圳市常见园林植物滞尘效应初步研究 总被引：2，自引：0，他引：2
采用蒸干称重法和显微观察法对深圳市28种常见园林绿化植物的滞尘能力及部分植物的滞尘方式进行了初步研究。单位叶面积滞尘量的测定结果表明,针状叶类乔木中:龙柏﹥木麻黄;阔叶类乔木中:麻楝>霸王棕>黄花夹竹桃>海枣>大花紫薇>长芒杜英>椰子>紫檀;灌木类中:紫薇>金叶榕=小蜡树>黄花马缨丹>锈鳞木犀榄>红花檵木>龙船花>散尾葵>紫雪茄花>大佛肚竹>四季桂>朱槿>棕竹>软叶刺葵>朱蕉;草本类中:中国文殊兰>花叶艳山姜>蔓花生。以显微观察比较叶片滞尘能力有显著差异的种类,紫薇、金叶榕、红花檵木和朱蕉的滞尘方式分别以颗粒物堆叠式、块状层结式、颗粒镶嵌式及零星嵌入式为主。研究筛选出的常见园林绿化植物中滞尘能力强的种类,可为相似大气环境的亚热带城市绿化提供优先选择,使其成为有效改善空气质量的生物基本元素。 相似文献
20.
The effectiveness of retention trees and patches in preserving diversity of nine epiphytic and epixylic old-growth forest lichens was studied in north boreal spruce forests in Finland. We compared (1) 7–8-year-old retention cuts, with at least 5–10 living or dead retention trees per hectare, (2) 10–12-year-old clear-cuts, with some scattered living and dead retention trees on the sites, (3) old-growth spruce forests, and (4) 7-8-year-old retention patches (0.06–0.45?ha) representing the original tree species composition of old-growth forests. The occurrence of indicator lichens was studied on 150 deciduous trees and snags in each forest category. The species richness was significantly higher in old-growth forests than in the clear-cuts and retention cuts, but did not differ between old-growth forests and retention patches. Only three species were found in clear-cuts and two in retention cuts. Foliose cyanolichens Leptogium saturninum and Nephroma bellum thrived on solitary retention trees, whereas humidity-requiring pin lichens from the genus Chaenotheca were found only in old-growth forests and retention patches. Our results suggest that the ability of epiphytic and epixylic species to survive on retained trees depends on several factors: (1) substrate quality (tree species, tree type and diameter of a tree), (2) environmental factors (e.g. humidity, slope exposition), and (3) morphological and physiological characteristics of species. Besides of substrate trees, the retained conifers (esp. spruce) seem to be important in retention patches to provide the shading necessary to maintain humidity. 相似文献