重庆市6种常见园林植物功能性状对城乡生境梯度的响应

功能性状作为联系植物、环境与生态系统的桥梁,对研究植物适应不同生境的策略意义重大。本研究以重庆主城区中华蚊母树(Distylium chinense)、鸡爪槭(Acer palmatum)、檵木(Loropetalum chinense)、构树(Broussonetia papyrifera)、银杏(Ginkgo biloba)、玉兰(Magnolia denudata)为对象,遴选植物功能性状及生物量分配指标,定量分析了其在不同城市环境下的差异性,旨在考查植物对于城市生态环境的适应策略。结果表明:除比叶面积和生物量分配比例外,其他功能性状包括营养器官和生殖器官随乡-郊-城环境梯度发生显著变化(P<0.05),表现为其数值随环境梯度显著下降;除鸡爪槭外,其余5种植物分配给繁殖器官的资源最多,分配给茎的资源最少;根据植物功能性状主成分分析,将6种植物分为3类:营养器官和生殖器官基本未受城市环境影响类,营养器官未受影响而生殖器官受损类,以及营养和生殖器官均受损类;植物功能性状综合评价显示,在森林公园中植物性状表现最好,郊区公园次之,城市公园中最差。     

高浓度CO2对三种澳大利亚园林植物插条的影响

在繁殖棚内昼夜施放ＣＯ２,使棚内ＣＯ２浓度保持在８００±１００μｌＬ－１,对三种澳大利亚园林植物：Ｃｈａｍｅｌａｕｃｉｕｍｕｎｃｉｎａｔｕｍ、Ｃｏｒｒｅａｒｅｆｌｅｘａ和Ｐｒｏｓｔａｎｔｈｅｒａｉｎｃｔｓａ进行插条试验。结果表明：高浓度ＣＯ２处理的Ｃｈａｍｅｌａｕｃｉｕｍｕｎｃｉｎａｔｕｍ和Ｃｏｒｒｅａｒｅｆｌｅｘａ插条干物质重量和淀粉含量显著增加,使插条出根早、出根率高和根量多,据后４０ｄ的插条出根率分别比对照高２６．６％和３３．４％．然而,同样的ＣＯ２处理对Ｐｒｏｓｔａｎｔｈｅｒａｉｎｃｉｓａ的插条没有明显影响。这可能是由于后者对ＣＯ２处理不敏感之故。     

大气污染对35种园林植物生长的影响

对广东省佛山市大气监测的结果表明,酸性硫化物和毒性氟化物是陶瓷工业产生的主要污染物质。采用现场盆栽试验方法。比较分析了生长在佛山市陶瓷城附近高浓度SO2和氟化物大气污染环境下的35种园林绿化植物的株高、基径、冠幅等生长指标的差异,并采用综合生长指标评价方法对参试植物进行相应的抗性分级,选出8种抗性植物（铁冬青、菩提榕、环榕、仪花、小叶榕、红花油茶、幌伞枫、白桂木）,17种中等抗性植物（小叶胭脂、腊肠树、毛黄肉楠、红桂木、茶花、吊瓜、火焰木、铁力木、柳叶楠、猫尾木、灰莉、密花树、海南红豆、复羽叶栾树、灰木莲、大头茶、印度紫檀）,8种敏感植物（华润楠、海南木莲、格木、日本杜英、蓝花楹、观光木、蝴蝶树、白木香、乐昌含笑、无忧树）。     

广州市园林植物上三种细蛾发生初报

首次报道了广州市危害园林植物上有 3种细蛾科新害虫榕细蛾Melanocercopsficuvorella(Yazaki) ,假柿树突细蛾Gibbovalvaquadrifasciata(Stainton) ,木兰突细蛾G .urbana(Meyrick)。该文对它们的分布与危害、形态特征及习性进行了描述     

四种园林植物对土壤镉污染的耐受性

采用模拟Cd污染土壤培养法,测定了Cd胁迫下山矾、桑树、绣线菊、山茶4种园林植物幼苗的生长、生物量变化,根茎叶的Cd含量,光合色素含量与MDA含量,对耐性指数(Ti)、转移系数(TF)、生物富集系数(BCF)进行了评价。结果表明:(1)山矾、桑树、绣线菊和山茶的平均耐性指数分别为93.99、82.33、82.10和87.25;(2)4个树种幼苗根茎叶的Cd含量都随着Cd处理浓度的增加而增加,转移系数值(TF)都小于1,转移能力为山矾山茶绣线菊桑树。对Cd累积能力为山矾山茶桑树绣线菊;山矾和山茶生物量吸收的Cd总量显著高于绣线菊和桑树。(3)Cd处理浓度的不断增加,叶绿素a/叶绿素b比值与对照相比变化不显著,类胡萝卜素的含量持续增加;桑树、山茶、山矾和绣线菊MDA含量分别平均上升为15%、10.17%、9.69%、12.86%。不同Cd浓度下,MDA上升幅度顺序为桑树绣线菊山茶山矾。研究表明山矾具有很高的Cd耐性、转移能力、以及地上部分积累镉的能力,是一种抗Cd污染较好的园林绿化树种。     

深圳7种园林植物叶绿素荧光特性及其对大气SO2浓度的响应

叶绿素荧光信号能快速灵敏地反映植物生理状态及其与环境的关系,是一种理想光系统探针。测定了深圳市7种园林植物叶片的叶绿素荧光参数和叶绿素含量,并对这些生理参数与大气污染物SO₂的相关性进行了分析。结果表明,7种植物叶片的叶绿素含量具有明显的种间差别,生境的差别远小于种间差别。所测定的7种园林植物的F_v/F_m相差不大,平均为0.78,低于理想条件下的最大值,说明存在一定的生长胁迫。叶绿素荧光的光化学淬灭qP的种间差别不明显。非光化学猝灭系数qN的种类差别较大,白兰Michelia alba和短穗鱼尾葵Caryota mitis具有较高的非光化学淬灭能力,说明这两个种具有一定的光保护能力。7种植物中,白兰的ΦpsⅡ要明显地较低于其它植物。深圳大气污染对城区植物的生理生化特性尚未构成不良影响,在深圳市区的环境中,短穗鱼尾葵、勒杜鹃Bougainvillea spectabilis和阴香Cinnamomum burmanii的叶绿素荧光参数可以作为大气污染物的指示指标;大红花Hibiscus rosa-sinensis、九里香Murraga paniculata、白兰和黄叶假连翘Duranta cv Golden Leaves具有相对较高抗污染物的能力。植物的叶绿素荧光参数也在一定程度上受到叶绿素的影响,阴香、短穗鱼尾葵、大红花和九里香的部分叶绿素荧光参数与植物叶片叶绿素含量呈正相关。     

光照和温度对大绒鼠产热特征的影响

为了解横断山地区大绒鼠对光照和温度两个因子的适应性特征,将大绒鼠分为4组,分别于5±1℃,6L:18D:5±1℃,18L:6D;30±1℃,6L:18D和30±1℃,18L:6D 4个条件下驯化28 d.分别测定了对照组(0 d)和驯化28 d后,每一个体的体重、体温和产热能力;并测定驯化28 d后4组大绒鼠个体的肝脏和褐色脂肪组织的产热活性变化.结果显示,在低温诱导下大绒鼠体重下降,体温降低,静止代谢率升高,非颤抖性产热能力增加,肝脏和褐色脂肪组织的产热活性也出现相应提升;在高温下出现与低温时相反的现象;但光照周期对大绒鼠的体重、体温、产热能力及肝脏和褐色脂肪组织的产热活性均没有显著影响.推测由于横断山的低纬度、高海拔特征可能导致大绒鼠在季节适应过程中对温度的敏感程度高于光照.     

30种园林植物对短期大气污染的生理生态反应

 30种2～3年生园林植物分别盆栽于不同污染强度的工业生产区、交通繁忙区和相对清洁区,在第一生长季结束后对各试验区植物叶片气体交换特征参数进行测定,评价了大气污染对不同植物种类的可能影响效果。结果表明：工业污染区和交通繁忙区均有较高的SO2浓度,交通繁忙区NOx浓度明显高于其它试验区。根据综合污染指数,3个试验区污染强度为交通繁忙区>工业污染区>相对清洁区。生长在污染区的大多数植物的净光合速率（Pn）、蒸腾速率(E)和气孔导度（gs） 均出现不同程度的下降,下降幅度因植物种类不同而有较大差异。植物Pn、E与gs之间存在显著线性相关关系,表明多数植物能够感应污染胁迫和调节气孔开张度,是植物对胁迫环境的一种适应策略。但是污染胁迫下Pn、E与gs线性相关的显著程度被削弱,表现出污染胁迫下不同植物种类Pn和E的变化与gs变化的不协同性和复杂性。根据Pn下降程度可将植物分组为轻度敏感（11种）、中度敏感（11种）和高度敏感植物（8种）。      

亚热带典型绿化灌木对夜间人工光照的生理响应

夜间人工光照正在迅速蔓延，成为全球变化的一个重要组成部分。尽管许多研究关注了它的潜在生态影响，但绿化植物对夜间人工光照的生理响应机制研究相对匮乏。本研究以我国亚热带地区常见的城市绿化灌木圆锥绣球、红叶石楠和金森女贞为对象，模拟不同光质(黄光、白光)下不同光强(20、40和60 lx)的夜间光环境，研究植物抗氧化酶系统以及生物量的响应特征。结果表明：夜间人工光照显著提高了3种灌木的细胞膜质过氧化程度，激发了植物抗氧化保护系统，显著提高了抗氧化酶活性。光质对植物抗氧化酶的影响因植物种类而异，圆锥绣球在白光下的过氧化物酶(POD)和过氧化氢酶(CAT)活性分别是黄光下的1.5和1.3倍，红叶石楠2种酶活性在白光下均为黄光下的1.1倍，而金森女贞2种酶活性在白光下分别是黄光下的88.6%和99.5%。3种灌木抗氧化酶活性随夜间光强的增加而增加，但超过一定光强阈值(120 d时，阈值约为40 lx)后，丙二醛含量迅速增加，抗氧化酶活性降低。3种灌木在夜光胁迫下起主要作用的保护酶不同，圆锥绣球通过POD与CAT互补来抵御胁迫带来的氧化伤害，金森女贞的主要作用酶为POD。3种灌木在夜间人工光照下生物...     

Dim light at night increases body mass of female mice

During the past century, the prevalence of light at night has increased in parallel with obesity rates. Dim light at night (dLAN) increases body mass in male mice. However, the effects of light at night on female body mass remain unspecified. Thus, female mice were exposed to a standard light/dark (LD; 16?h light at ～150?lux/8?h dark at ～0?lux) cycle or to light/dim light at night (dLAN; 16?h light at ～150?lux/8?h dim light at ～5?lux) cycles for six weeks. Females exposed to dLAN increased the rate of change in body mass compared to LD mice despite reduced total food intake during weeks five and six, suggesting that dLAN disrupted circadian rhythms resulting in deranged metabolism.     

The association between artificial light at night and prostate cancer in Gwangju City and South Jeolla Province of South Korea

Exposure to artificial light at night (ALAN) has been reported to be associated with various pathological changes including sleep deprivation, circadian rhythm disruption, and melatonin suppression with increase in various cancers such as breast or prostate cancers. In this study, we sought to elucidate the association between ALAN and prostate cancer in 27 districts within Gwangju City and urban and rural areas from South Jeolla Province in South Korea. We analyzed the correlation between ALAN and the incidence of a range of cancers by Poisson regression analysis, after adjustment for confounding risk factors, such as smoking, drinking, obesity, stress, air pollution (particulate matter <10 μm in diameter), urbanization (proportion of urbanized area), and the cancer screening rate. Interestingly, the incidence of prostate cancer was significantly associated with ALAN (risk ratio = 1.02, p = 0.0369) and urbanization (risk ratio = 1.06, p = 0.0055). In particular, comparing the prostate cancer incidence at 25% and 75% level of ALAN, the risk ratio was 1.726 (12.6 over 7.3, respectively). No significant association was observed between ALAN and other cancers, including stomach, esophageal, liver, pancreatic, laryngeal, lung and tracheal, bladder, and brain and central nervous system cancers, as well as lymphoma and multiple myeloma. In conclusion, this study shows that a high incidence of prostate cancer may be independently associated with light pollution and urbanization, which represent significant factors in the rapid process of industrialization of South Korea.     

三种相思植物对短期大气污染的响应

3种2－3年生相思盆栽于代表不同污染程度的交通繁忙区、工业生产区和相对清洁区,4个月后进行植物叶片气体交换和叶绿素荧光特征参数的测定。结果表明,生长在污染区的相思植物的净光合速率（Pn）、气孔导度（gs）和光系统Ⅱ原初光化学效率（Fv／Fm）均出现不同程度的下降,下降幅度因植物种类和污染类型的不同而有差异,不同实验点上大腺相思叶片蒸腾速率（E）和水分利用效率（WUE）则维持相对稳定,多花和流苏相思的WUE均以污染环境下较低,根据Pn、gs和Fv/Fm的变化以及实验点上其它植物对应测定值比,推测3种相思植物对大气污染都表现出中等强度的抗性,且多花相思和流苏相思相对好于大腺相思。     

Artificial light at night affects the timing of roosting by Chimney Swifts

Understanding the impact of anthropogenic threats, such as light pollution, on biodiversity is necessary to establish effective guidelines to protect diminishing wildlife. In this study, we examined the effect of artificial light at night (ALAN) on the roosting behaviour of Chimney Swifts Chaetura pelagica, a highly threatened migratory bird species that lives commensally with humans, where it often breeds and roosts in artificial structures such as chimneys. Although Chimney Swifts are known to use time of sunset in combination with temperature, wind and season to coordinate roost entry, we predicted that high ALAN exposure would override these natural cues and lead to a delayed entry compared with sites with less light pollution. To test this, we examined the effects of ALAN on the start and end times of entry to 21 roosting sites located along a light pollution gradient in New Jersey and the New York Metropolitan area. We found that ALAN was a significant predictor of roosting entry time, with birds entering later in sites with more light pollution. While Chimney Swifts initiated roosting earlier in the summer months compared with the autumn, this effect was absent in areas with high light pollution. These findings highlight the need to determine the causes and consequences of light pollution effects.     

Cascading effects of artificial light at night: resource-mediated control of herbivores in a grassland ecosystem

Artificial light at night has a wide range of biological effects on both plants and animals. Here, we review mechanisms by which artificial light at night may restructure ecological communities by modifying the interactions between species. Such mechanisms may be top-down (predator, parasite or grazer controlled), bottom-up (resource-controlled) or involve non-trophic processes, such as pollination, seed dispersal or competition. We present results from an experiment investigating both top-down and bottom-up effects of artificial light at night on the population density of pea aphids Acyrthosiphon pisum in a diverse artificial grassland community in the presence and absence of predators and under low-level light of different spectral composition. We found no evidence for top-down control of A. pisum in this system, but did find evidence for bottom-up effects mediated through the impact of light on flower head density in a leguminous food plant. These results suggest that physiological effects of light on a plant species within a diverse plant community can have detectable demographic effects on a specialist herbivore.     

Advanced photobioreactor LED illumination system: Scale‐down approach to study microalgal growth kinetics

A newly designed and constructed LED illumination device for commercial cylindrical bioreactors is presented for application in microalgal cultivations and investigation of growth kinetics. An ideally illuminated volume is achieved by focusing the light toward the center of the reactor and thereby compensating the mutual shading of the cells. The relevant biomass concentration for homogeneous illumination depending on reactor radius was determined by light distribution measurements for Chlamydomonas to 0.2 g/L (equal 0.435 optical density at 750 nm). It is shown that cultivation experiments with the newly designed illumination device operated in batch mode can be successfully applied for determination of growth rates and photo conversion efficiencies. The exact knowledge of physiological reactions of specific strain(s) and the estimation of relevant parameters for scale‐up can be used for construction of economic pilot plant photobioreactors. The determination of light‐dependent kinetics of growth and product formation is the first necessary step to achieve this. A wide variety of different parameters can be examined like the effect of different illumination conditions (light intensity, frequency of day/night cycles, flashing light, light color…) and thereby for each single application specific, relevant, and interesting parameters will be examined.     

An integrated solar and artificial light system for internal illumination of photobioreactors

Exploitation of photosynthetic cells for the production of useful metabolites requires efficient photobioreactors. Many laboratory scale photobioreactors have been reported but most of them are extremely difficult to scale up. Furthermore, the use of open ponds and outdoor tubular photobioreactors is limited by the requirement for large spaces and the difficulty in maintaining sterile conditions. In view of this, we have designed and constructed an internally illuminated stirred tank photobioreactor. The photobioreactor is simple, heat sterilizable and mechanically agitated like the conventional stirred tank bioreactors. Furthermore, it can easily be scaled up while maintaining the light supply coefficient and thus the productivity constant. A device was installed for collecting solar light and distributing it inside the reactor through optical fibers. It was equipped with a light tracking sensor so that the lenses rotate with the position of the sun. This makes it possible to use solar light for photosynthetic cell cultivation in indoor photobioreactors. As a solution to the problems of night biomass loss and low productivity on cloudy days, an artificial light source was coupled with the solar light collecting device. A light intensity sensor monitors the solar light intensity and the artificial light is automatically switched on or off, depending on the solar light intensity. In this way, continuous light supply to the reactor is achieved by using solar light during sunny period, and artificial light at night and on cloudy days.     

Exposure to dim artificial light at night increases REM sleep and awakenings in humans

Exposure to artificial light at night (ALAN) has become increasing common, especially in developed countries. We investigated the effect of dALAN exposure during sleep in healthy young male subjects. A total of 30 healthy young male volunteers from 21 to 29 years old were recruited for the study. They were randomly divided into two groups depending on light intensity (Group A: 5 lux and Group B: 10 lux). After a quality control process, 23 healthy subjects were included in the study (Group A: 11 subjects, Group B: 12 subjects). Subjects underwent an NPSG session with no light (Night 1) followed by an NPSG session randomly assigned to two different dim light conditions (5 or 10 lux, dom λ: 501.4 nm) for a whole night (Night 2). We found significant sleep structural differences between Nights 1 and 2, but no difference between Groups A and B. Exposure to dALAN during sleep was significantly associated with increased wake time after sleep onset (WASO; F = 7.273, p = 0.014), increased Stage N1 (F = 4.524, p = 0.045), decreased Stage N2 (F = 9.49, p = 0.006), increased Stage R (F = 6.698, p = 0.017) and non-significantly decreased REM density (F = 4.102, p = 0.056). We found that dALAN during sleep affects sleep structure. Exposure to dALAN during sleep increases the frequency of arousals, amount of shallow sleep and amount of REM sleep. This suggests adverse effects of dALAN during sleep on sleep quality and suggests the need to avoid exposure to dALAN during sleep.     

Light at night,clocks and health: from humans to wild organisms

The increasing use of electric lights has modified the natural light environment dramatically, posing novel challenges to both humans and wildlife. Indeed, several biomedical studies have linked artificial light at night to the disruption of circadian rhythms, with important consequences for human health, such as the increasing occurrence of metabolic syndromes, cancer and reduced immunity. In wild animals, light pollution is associated with changes in circadian behaviour, reproduction and predator–prey interactions, but we know little about the underlying physiological mechanisms and whether wild species suffer the same health problems as humans. In order to fill this gap, we advocate the need for integrating ecological studies in the field, with chronobiological approaches to identify and characterize pathways that may link temporal disruption caused by light at night and potential health and fitness consequences.     

Exposure to light at night accelerates aging and spontaneous uterine carcinogenesis in female 129/Sv mice

The effect of the constant illumination on the development of spontaneous tumors in female 129/Sv mice was investigated. Forty-six female 129/Sv mice starting from the age of 2 mo were kept under standard light/dark regimen [12 h light (70 lx):12hr dark; LD, control group], and 46 of 129/Sv mice were kept under constant illumination (24 h a day, 2,500 lx, LL) from the age of 5 mo until to natural death. The exposure to the LL regimen significantly accelerated body weight gain, increased body temperature as well as acceleration of age-related disturbances in estrous function, followed by significant acceleration of the development of the spontaneous uterine tumors in female 129/Sv mice. Total tumor incidence as well as a total number of total or malignant tumors was similar in LL and LD group (p > 0.05). The mice from the LL groups survived less than those from the LD group (χ² = 8.5; p = 0.00351, log-rank test). According to the estimated parameters of the Cox’s regression model, constant light regimen increased the relative risk of death in female mice compared with the control (LD) group (p = 0.0041). The data demonstrate in the first time that the exposure to constant illumination was followed by the acceleration of aging and spontaneous uterine tumorigenesis in female 129/Sv mice.