北京远郊区臭氧污染及其对敏感植物叶片的伤害

臭氧(O3)是一种氧化性很强且生物危害很大的二次污染物.监测表明北京远郊区O3浓度高于近郊区和城区,经常超过敏感植物O3临界浓度(78.5μg/m3),自然植物的暴露剂量AOT40(超过78.5 μg/m3的空气O3浓度小时值累计量)值达到了98.9mg/m3,可能已经对植物生长造成危害.通过对远郊区O3浓度监测点(北京蟒山森林公园)26种乔木和灌木植物的调查,参考国外有关植物野外观测和模拟实验的植物O3伤害症状特征及植物O3伤害鉴别标准,发现其中15种植物出现了比较明显的O3伤害症状,表现为叶片出现点状、块状黄斑或褐色灼伤状干枯,表明北京远郊区的乔木和灌木已经受到了空气O3污染的危害.另外11种植物也出现了类似O3危害的伤害症状,需要进一步的研究验证是否由O3污染造成.     

北京夏季地表臭氧污染分布特征及其对植物的伤害效应

臭氧是重要的空气氧化剂,适当浓度的臭氧可以消菌杀毒,但过高浓度的臭氧可能对生物健康构成威胁。随着城市汽车保有量的迅速上升,臭氧的前体物氮氧化物和VOCs排放增多,臭氧浓度随之不断升高,地表臭氧污染日趋严重。地表臭氧的分布特征以及其对植物的胁迫伤害效应引起了人们的重视。是通过监测北京夏季地表臭氧污染分布规律,鉴定是否有植物受到臭氧伤害,以及受伤害植物的种类及地理分布特征,为城市与区域臭氧风险评估提供依据。从2012年7月4日到8月30日,采用被动采样分析的方法,在北京东北、西北、西南、东南郊区以及城区设置了10个研究样点,监测平均臭氧浓度的变化。同时,运用"森林健康专家咨询系统"鉴定植物受臭氧伤害的特征。结果表明:(1)监测期间,北京西部和北部山区的臭氧浓度高于平原地区;在平原地区,公园中的臭氧浓度高于道旁绿化带;山区的臭氧浓度平均为105.39μg/m3,公园中为68.49μg/m3,道旁绿化带为56.54μg/m3;(2)在北京的公园和山区发现了18种植物符合"森林健康专家咨询系统"所述臭氧伤害特征,有五叶地锦(Parthenocissus quinquefolia)、核桃(Juglans regia)、臭椿(Ailanthus altissima)、喇叭花(Pharbitis purpurea)、桑树(Morus alba)、榆树(Ulmus pumila)、国槐(Sophora japonica)金叶槐(Sophora japonica f.flavi-rameus)、木槿(Hibiscus syriacus)、重瓣棣棠花(Kerria japonica)、山香(Hyptis suaveolens)、决明(Cassia tora)、毛白杨(Populus tomentosa)、黄花柳(Salix caprea)、大花地榆(Sanguisorba sitchensis)、火炬树(Rhus typhina)、大豆(Glycine max)、向日葵(Helianthus annuus);没有在道旁绿化带的植物叶片发现臭氧伤害症状;(3)臭椿(Ailanthus altissima)幼树臭氧伤害症状明显,易于辨认,且臭椿出现频率最高,是分布广泛的乡土树种,适合作为臭氧污染指示植物。     

钙对臭氧伤害小麦的防护作用

春小麦分别用0、1‰、3‰、5‰浓度的CaCl_2溶液浸种及培养,9天后,用0.3—0.7ppm浓度的臭氧(O_3)对幼苗熏气0、4、8、12h,观测到来经Ca~(2+)处理材料的叶片,其外渗液紫外吸收值和电导率随O_3处理时间延长都有不同程度的升高,而叶内可溶性糖和叶绿素含量都明显降低,经过3‰Ca~(2+)处理O_3熏气4—12h的材料,其外渗液紫外吸值、电导率、外渗糖、蒸腾强度都低于对照,其叶内可溶性糖及叶绿素含量均高于对照,证收明在一定O_3浓度范围内,3‰CaCl_2对O_3侵害小麦有明显的防护作用。     

大气污染对38种木本植物的伤害特征

38种苗龄1—2a生的木本植物盆栽于相对清洁区(华南植物园和2个污染点：佛山市南海区五星和佛山市禅城区东村。1a后,根据叶片伤害程度、新叶增长率、种个体长势、翌春植株恢复状况等综合评价植物对氟化物、硫化物和酸雨组成的大气复合污染的敏感性反应。根据试验结果将供试植物对大气污染的敏感性反应分为3种类型：(1)低敏感性(抗性强),有茶花、红花油茶、傅园榕、小叶榕、桂花、环榕、菩提榕、石笔木、毛黄肉楠、幌伞枫10种。(2)中等敏感(抗性中等),有仪花、格木、吊瓜树、腊肠树、海南红豆、猫尾木、红桂木、灰莉、铁冬青、密花树、白桂木、小叶胭脂、大头茶、复羽叶栾、灰木莲、火焰木、华润楠17种。(3)高度敏感(抗性弱),有铁刀木、观光木、白木香、日本杜英、蓝花楹、蝴蝶树、印度紫檀、柳叶楠、无忧树、海南木莲、乐昌含笑11种。研究结果可为热带、南亚热带地区有类似大气污染的环境进行园林绿化,生态公益林营造提供参考。     

臭氧和氟化氢复合熏气对小麦叶片形态和生理机能的影响

用开顶式熏气装置,研究了臭氧（Ｏ＿３）和氟化氢（ＨＦ）单独与复合熏气对春小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）叶片伤害症状、叶片的膜透性、糖和叶绿素含量的影响。结果表明,复合熏气比单独熏气对叶片的伤害更重,它们都使膜透性增大,叶绿素含量下降。熏气初期可溶性糖含量升高,伤害加重时则含量下降。研究还得出Ｏ＿３和ＨＦ复合熏气对小麦的伤害具有联合作用,对幼叶的伤害具有协同效应,而对老龄叶的危害似有一定的拮抗作用。     

臭氧对植物的影响

臭氧（Ｏ３）是一种主要的光化学氧化剂。由汽车废气及石油、煤炭等燃烧排入大气的碳氢化合物（ＨＣ）和氮氧化物（ＮＯｘ）等一次污染物在阳光（紫外线）作用下,会发生光化学反应,生成氧化能力很强的二次污染物,包括Ｏ３、过氧乙酰硝酸酯和醛类等化学氧化剂。其中很大部分是Ｏ３,约占９０％以上。目前,Ｏ３已是分布很广泛的大气污染物,成为突出的环境污染问题,严重影响植物的生长发育。一、Ｏ３对植物的伤害症状及伤害阈值植物受Ｏ３伤害的症状,一般出现于成熟的叶片上,嫩叶不易出现症状。受害后出现伤斑,零星分布于全叶各部分。…     

大气颗粒污染物对植物的伤害

根据近年来关于大气颗粒污染物的研究成果,综合论述了大气颗粒污染物对植物造成的直接伤害和间接伤害情况以及影响颗粒污染物危害程序的因子。     

环境大气臭氧污染对植物的影响（二）

(一) 急性影响在O_3暴露下,O_3是在植物的叶片与环境大气进行正常的气体交换时,通过开放着的气孔而进入叶片,并溶解在叶的组织液中,经浓度梯度而扩散的。而且,气孔是O_3进入叶组织的主要途径,通过吸咐于叶表皮并经角质层进入叶肉细胞而扩散的O_3的数量是可以忽略的。O_3或其中间物(例如OH基团)一旦进入气孔下室,便首先侵犯周围组织的纤维素细胞壁。虽未证明纤维素可遭受这种强氧化剂的毒害,但已知O_3确实可破坏细胞质膜蛋白质和脂类的巯基和脂键,使质膜上水和离子的通透性遭受影响,细胞的整合性丧失,从而导致细胞的内含物泄漏入胞间腔隙。此时叶片的受害区呈暗绿色或水渍状。这是O_3对叶片毒害最早的可见症状。数小时后,O_3穿过质膜进入细胞器首先是     

二氧化硫对蚕豆叶片伤害类型的研究

二氧化硫熏气处理后对蚕豆（ＶｉｃｉａｆａｂａＬ．）叶片的伤害可划为３种类型,即不可见伤害、可逆的可见伤害以及不可逆伤害。采用动态熏气的方法初步估计了３类伤害的阈值,不可见伤害阈值小于１３１．２μｇ／ｍ￣３×８ｈｓ,可见伤害阈值为１３２２．８μｇ／ｍ￣３×２ｈｓ,１３２２．８μｇ／ｍ￣３ＳＯ＿２处理时不可逆伤害阈值介于１６ｈｓ（累积小时数,下同）和２４ｈｓ之间,而以７７５．０μｇ／ｍ￣３ＳＯ＿２处理时,则介于３２ｈｓ和４０ｈｓ之间。认为超氧化物歧化酶活性作为不可见伤害和不可逆伤害的指标较为适宜,可见伤害阈值则可沿用传统的５％伤害叶面积作指标。     

膜脂过氧化对植物细胞的伤害

本文综述了近年来有关膜脂过氧化对植物细胞膜系统的结构和功能、细胞的蛋白质代谢、光合作用和呼吸作用等过程的伤害机理方面的研究进展。     

Effect of ozone exposure on polyamines in Scots pine trees

Effects of ozone exposure on polyamines in Pinus sylvestris L. were studied in a long-term experiment. Ten- to 15-year-old Scots pines were exposed to target ozone levels which began at ambient + 40 ppb in May, decreasing to ambient air only by September for 3 growing seasons. The amount of ozone applied followed the natural pattern of variation in ozone concentrations in Northern Finland. The free, soluble conjugated and insoluble conjugated polyamines were analyzed during the experiment and shortly after termination of exposure as well as at the beginning of the following growing season. A carry-over effect was observed as ozone-induced reduction of free spermidine in the oldest needle year class, which developed during the first exposure season of the experiment. This reduction was observed both after the second and the third ozone exposure season. Conversely, after termination of the experiment, levels of free polyamines increased in the following growing season, and soluble conjugated polyamines decreased in the developing needles. The post-treatment changes in polyamine concentrations are hypothesized to be caused by stress-induced injuries or delayed recovery of metabolic processes rather than protective responses. It is noteworthy that some responses in polyamines were found in the developing needles nine months after terminating the ozone exposure. This suggests that stress-induced injuries to older needles affected metabolism of new developing needles.     

蔷薇科一些植物鲜叶提取物清除DPPH自由基活性的研究

用二苯基苦基苯肼自由基酶标仪法,对业热带蔷薇科常见的50种木本植物鲜叶的自由基清除活性进行了比较,发现不同属、不同种树木鲜叶的80%甲醇提取物的自由基清除活性有很大差异,其中苹果属5种植物在相当于鲜叶浓度为0.5mg/mL于37℃下孵育20min时,对0.5mmol·L-1DPPH自由基平均清除率达62.4%,而绣线菊属3种植物的平均自由基清除率仅11.6%.尖嘴林檎、棣棠、木瓜、三叶海棠、湖北海棠、木香花、小果蔷薇和黄山花楸等鲜叶有较强的自由基清除活性,它们在浓度为0.5mg/mL时的自由基清除率分别可达85.0%、75.8%、70.7%、69.6%、64.5%、62.5%、61.8%和61.3%,显示其有较大的开发潜力.     

The Distribution of a Phytochrome-Like Protein in the Fern Psilotum nudum.; An Immunoblotting Analysis of an Early Ancestor of all Vascular Plants

The distribution of a 125 kg . mol^?1 protein recognized by a monoclonal antibody raised against phytochrome of maize was analyzed in the sporophyte of the fern Psilotum nudum. Highest amounts (up to 5 μg per fresh weight) of this protein were found in the tips of expanding shoots. Green sporangia as well as the pale tips of the rhizome contained this 125 kg . mol^?1 protein, too. In the brown parts of the rhizome it was more rarely contained. Unlike phytochrome from etiolated higher plants, the Psilotum protein appeared to be scarcely degraded by the illuminated plants. In this respect the protein of Psilotum seems to resemble the small fraction of phytochrome contained in green and illuminated higher plants. Moreover, after illuminating the Psilotum rhizome for 3 d, higher amounts of this protein were detected therein as before.     

我国南沙群岛岛礁引种植物调查

为了解南沙群岛岛礁的引种植物,2012年8–9月对南沙群岛的7个岛礁进行了实地调查,并对岛礁上的植物种类、生长情况进行了分析。结果表明,7个岛礁上引种的维管植物有36科62属79种。根据邻近西沙群岛和南沙岛屿的植物种类,提出适合南沙岛礁生长引种的植物种类,为绿化南海岛屿(礁)提供参考。     

Evidence of widespread effects of ozone on crops and (semi‐)natural vegetation in Europe (1990–2006) in relation to AOT40‐ and flux‐based risk maps

Records of effects of ambient ozone pollution on vegetation have been compiled for Europe for the years 1990–2006. Sources include scientific papers, conference proceedings, reports to research funders, records of confirmed ozone injury symptoms and an international biomonitoring experiment coordinated by the ICP Vegetation. The latter involved ozone‐sensitive (NC‐S) and ozone‐resistant (NC‐R) biotypes of white clover (Trifolium repens L.) grown according to a common protocol and monitored for ozone injury and biomass differences in 17 European countries, from 1996 to 2006. Effects were separated into visible injury or growth/yield reduction. Of the 644 records of visible injury, 39% were for crops (27 species), 38.1% were for (semi‐) natural vegetation (95 species) and 22.9% were for shrubs (49 species). Owing to inconsistencies in reporting effort from year to year it was not possible to determine geographical or temporal trends in the data. Nevertheless, this study has shown effects in ambient air in 18 European countries from Sweden in the north to Greece in the south. These effects data were superimposed on AOT40 (accumulated ozone concentrations over 40 ppb) and POD3_gen (modelled accumulated stomatal flux over a threshold of 3 nmol m^?2 s^?1) maps generated by the EMEP Eulerian model (50 km × 50 km grid) that were parameterized for a generic crop based on wheat and NC‐S/NC‐R white clover. Many effects were found in areas where the AOT40 (crops) was below the critical level of 3 ppm h. In contrast, the majority of effects were detected in grid squares where POD3_gen (crops) were in the mid‐high range (>12 mmol m^?2). Overall, maps based on POD3_gen provided better fit to the effects data than those based on AOT40, with the POD3_gen model for clover fitting the clover effects data better than that for a generic crop.     

南昌市中心城区主要大气污染物分布模拟及土地利用对其影响

随着我国城市化、工业化的快速推进,城市大气污染问题日益突出,研究城市大气污染物的分布情况及其土地利用影响对解决城市大气污染问题具有重要意义.本研究以南昌市中心城区为研究区,基于土地利用回归模型(LUR)模拟了PM_2.5、PM₁₀、SO₂、NO₂、CO、O₃等6种主要大气污染物浓度,并分析其时空分布特征;基于主导土地利用类型,选择南昌市中心城区内居住、商业、教育和工业用地各15个样本区,为了减少气象因子的影响,分四季统计各样本区6类大气污染物浓度,运用双因素方差分析和多重比较,定量分析土地利用(样本区)对6类大气污染物的影响.结果表明: 采用LUR模型模拟研究区PM_2.5、PM₁₀、SO₂、NO₂、CO、O₃浓度的平均绝对误差率分别为11.9%、13.4%、12.5%、12.0%、12.7%和13.5%,模型误差较小,方法可行.研究区6类污染物浓度具有明显的时空分布特征,PM_2.5、PM₁₀、SO₂、NO₂和CO浓度在冬季最高,春季和秋季次之,夏季最低;O₃浓度则为夏季高,春季和秋季次之,冬季低.PM_2.5、PM₁₀、SO₂、NO₂、CO浓度整体呈现从城区中心到郊区递减的趋势,而O₃浓度则反之.不同季节与不同土地利用样本区间6种大气污染物浓度差异显著,表明在中心城区尺度上,气象条件和土地利用都对大气污染物有显著影响.不同土地利用对主要大气污染物浓度分布有不同程度的影响,其中,对PM_2.5、NO₂和O₃的影响较大,对CO的影响较小.     

Tropospheric O(3) compromises net primary production in young stands of trembling aspen, paper birch and sugar maple in response to elevated atmospheric CO(2)

Concentrations of atmospheric CO(2) and tropospheric ozone (O(3)) are rising concurrently in the atmosphere, with potentially antagonistic effects on forest net primary production (NPP) and implications for terrestrial carbon sequestration. Using free-air CO(2) enrichment (FACE) technology, we exposed north-temperate forest communities to concentrations of CO(2) and O(3) predicted for the year 2050 for the first 7 yr of stand development. Site-specific allometric equations were applied to annual nondestructive growth measurements to estimate above- and below-ground biomass and NPP for each year of the experiment. Relative to the control, elevated CO(2) increased total biomass 25, 45 and 60% in the aspen, aspen-birch and aspen-maple communities, respectively. Tropospheric O(3) caused 23, 13 and 14% reductions in total biomass relative to the control in the respective communities. Combined fumigation resulted in total biomass response of -7.8, +8.4 and +24.3% relative to the control in the aspen, aspen-birch and aspen-sugar maple communities, respectively. These results indicate that exposure to even moderate levels of O(3) significantly reduce the capacity of NPP to respond to elevated CO(2) in some forests.     

C4 Plants in the Vegetation of Tibet,China: Their Natural Occurrence and Altitude Distribution Pattern

Floristic composition, life forms for C₄ species, and the pattern of altitude distribution were studied on Tibetan Plateau. 79 species, in 7 families and 46 genera, were identified with C₄ photosynthesis. 95 % of these C₄ species belong to Gramineae (51 species), Cyperaceae (14 species), and Chenopodiaceae (10 species), indicating that C₄ plants mainly occur in very few families (7 of 204) on the Tibetan Plateau. High altitude distribution for all the Chenopodiaceae C₄ species (> 3 000 m above sea level) suggests that plants of this kind have large tolerance to cold, dryness, and strong ultraviolet radiation. Most Gramineae and Cyperaceae C₄ species occurrences are consistent with extensive distribution of steppes and meadows in the vast flat of the central Plateau (1 000–3 000 m a.s.l.). Relatively high amount of hemicryptophyte form plants (44 %) in the region indicates that the vegetation, especially grassland, meadows, and steppe, are in good condition. There is a strong relationship between numbers of C₄ species and altitude in the Tibetan Plateau. Occurrence of C₄ species is significantly less in both high and low altitude plateaux in Tibet. Altitude distribution pattern for C₄ species in the region is not only consistent with the altitude and climate, but also with the vegetation types in altitude gradient.     

茶叶主要化学品质指标和茶树体部分微量元素的钙铝调控效应

以一年生茶树扦插苗为材料,采用水培法研究了添加钙铝对茶叶主要化学品质及茶树钙、铝、锌、铁吸收积累的调控效应.结果表明:(1)适量铝(10或20mg·L-1)有利于提高茶叶茶多酚、咖啡碱、黄酮、可溶性总糖和氨基酸的含量;添加钙可提高上述化学成分的含量,且在高铝浓度(30mg·L-1)下提高的幅度最大.(2)适量的铝可促进茶树对铝和铁的吸收和积累,而高浓度的铝(30mg·L-1)抑制茶树对铝和铁的吸收与积累;添加铝可降低茶树根对钙和锌的吸收,但适量添加铝不影响茎和叶对钙和锌的积累.(3)添加钙可提高茶树体钙的含量,降低铝和锌的吸收与积累,但对铁的吸收与积累没有明显影响.研究表明,铝和钙可调控茶叶化学品质含量和茶树体微量元素的吸收;合理控制茶园土壤铝积累,并适量补充钙可能有利于提高茶叶品质,创建生态高值茶园.     

Effects of Ozone Fumigation on Photosynthesis and Membrane Permeability in Leaves of Spring Barley, Meadow Fescue, and Winter Rape

Seedlings of spring barley, meadow fescue, and winter rape were fumigated with 180 μg kg⁻¹ of ozone for 12 d, and effect of O₃ on photosynthesis and cell membrane permeability of fumigated plants was determined. Electrolyte leakage and chlorophyll fluorescence were measured after 6, 9, and 12 d of fumigation, while net photosynthetic rate (P _N) and stomatal conductance (g _s) were measured 9 d after the start of ozone exposure. O₃ treatment did not change membrane permeability in fescue and barley leaves, while in rape a significant decrease in ion leakage was noted within the whole experiment. O₃ did not change the photochemical efficiency of photosystem 2 (PS2), i.e., F_v/F_m, and the initial fluorescence (F₀). The values of half-rise time (t_1/2) from F₀ to maximal fluorescence (F_m) decreased in fescue and barley after 6 and 9 d of fumigation. P _N decreased significantly in ozonated plants, in the three species. The greatest decrease in P _N was observed in ozonated barley plants (17 % of the control). The ozone-induced decrease in P _N was due to the closure of stomata. Rape was more resistant to ozone than fescue or barley. Apparently, the rape plants show a large adaptation to ozone and prevent loss of membrane integrity leading to ion leakage. This revised version was published online in August 2006 with corrections to the Cover Date.