不同类型景观水体浮游动物群落差异及其影响因素

探明不同类型景观水体中环境敏感型浮游动物群落特征差异及影响因素对景观水体生物多样性维持和水生生态系统保护十分重要。于2014年5月在上海选取具代表性的8个景观水体共设置35个采样点进行浮游动物采样调查,并同步测定水体环境指标。本次调查采集并鉴定浮游动物40种,其中轮虫29种,枝角类7种,桡足类4种。基于浮游动物群落组成进行聚类分析,所有采样点聚为四种景观类型:天然湖泊(淀山湖)、人工湖泊(滴水湖)、AAAA级公园水体(共青森林公园和古猗园)和普通综合性公园水体(世纪公园、和平公园、长风公园和车镜公园)。两种公园水体浮游动物种类较为丰富,多样性较高,各自约有40%的种为生境特有种,而淀山湖特有种仅1种(为猛水蚤),滴水湖3种均为蛭态类。物种相似性方面,大型天然淀山湖与人工滴水湖相似性最高(37.5%),普通公园水体次之(33.3%),与AAAA公园水体相似度最低(20%)。后两者间的相似性较高(27.8%),且两者与滴水湖的相似度均较低(18.5%和12.0%)。四类水体仅有3个共有种/类群:角突臂尾轮虫(Brachionus angularis)、螺形龟甲轮虫(Keratella co...     

广州市公园植物景观特色与品种配置相关性研究

通过植物调查和拍摄植物景观照片,采用风景质量评价方法,对广州市公园植物景观特色与品种配置的相关性进行研究,筛选能体现岭南园林风格及南亚热带植物景观特色的最佳植物配置模式,为植物造景提供科学依据。     

郑州市公园绿地景观特征对公园冷岛效应的影响

城市公园有助于缓解城市热岛效应,减少城市降温能耗。选取郑州市中心城区内44个主要公园,利用Landsat8遥感数据和土地利用数据,结合ENVI、ArcGIS、Fragstats、SPSS等软件分析公园冷岛效应的影响因素。冷岛强度的研究从景观特征、景观构成、景观配置3个层面来进行,结果表明:场地条件有限的情况下公园面积控制在20 hm²左右能产生较高冷岛强度;公园边界越简单冷岛效应越强,而植物和不透水表面斑块的边界越复杂公园冷岛效应越强;同等面积下有水体的公园与无水体的公园相比降温效果相差1℃左右;水体占比控制在14%左右公园冷岛强度较为显著;在进行公园景观配置时,公园内植物和水体的组合相比于不透水表面与植物的组合及不透水表面与水体的组合能产生更好的降温效应。利用标准差椭圆工具进一步分析公园冷岛强度的方向性,发现公园的冷岛方向主要与园内水体长轴以及园外高层建筑的分布有关。     

基于模糊数学法的景观温室评价——以华南植物园温室群为例

为探究景观温室评价因素与景观效果之间的关系,以华南植物园温室群景区为研究对象,采用模糊数学法对其景观效果进行了系统评价.华南植物园温室群景区可分为10个景观分区,从中可筛选出13个景观评价因素;其中,通用因素包含竖向设计(A)、空间趣味性(B)、景观层次性(C)、水景(D)、植物配置方式(E)、置石(I)、视域开阔度(J)、温室工程设施(K)和堆山方式(M),特色因素包含植物奇异性(F)、生态奇特性(G)、人工构筑物(H)和路面铺装(L);根据不同景观分区的情况确认各评价因素的组成并制作网络调查问卷,通过对调查数据的统计分析计算出各景观分区的隶属度,并利用徐罗曹李法获得不同评价因素的权重值.结果显示:10个景观分区的隶属度为0.816 ～0.685;其中,热带水生植物区、雨林奇观区和山地雨林区的隶属度较高,景观效果较好;沙漠植物温室和高山/极地室等分区的隶属度较低,景观效果有待改善.根据权重值可将13个评价因素对景观效果的影响程度划分为4个等级;其中,植物奇异性、人工构筑物、水景、竖向设计和路面铺装等评价因素对各景观分区景观效果影响较大,堆山方式和温室工程设施对景观效果影响微小.根据研究结果,建议在采用模糊数学法进行景观评价时应制定具有参考价值的评价指标体系和评语赋值标准.     

北京城市公园湿地的休憩吸引力评价

以北京地区20个城市公园湿地为研究对象,从公园湿地的景观质量、区位条件、可达性3方面构建了城市公园湿地休憩吸引力评价指标体系,并基于层次分析法赋权的综合指数评价方法,对公园湿地的休憩吸引力进行评价,最后通过实地问卷调查数据对休憩吸引力评价结果进行验证,结果表明:具有高休憩吸引力的公园湿地依次为颐和园、奥林匹克公园、青龙湖公园、北海公园、圆明园、玉渊潭公园、十渡、金海湖风景区、陶然亭公园、野鸭湖湿地,稻香湖湿地和珍珠湖风景区的休憩吸引力最低,其余8个公园湿地休憩吸引力一般.休憩吸引力评价结果与实际调查数据相符,说明所建立的评价指标体系与评价方法是可行的.20个公园湿地按照其休憩吸引力可聚为4类,据此可制定不同的管理对策.通过城市公园湿地休憩吸引力评价,分析城市公园湿地景观在休闲游憩方面所发挥的作用,可以为城市湿地公园的优化与配置、提高人居环境质量、改善城市景观布局提供依据.     

上海市中小型河道沉积物和水生植物中重金属累积特征研究

采用野外调查和室内分析相结合的方法,以上海市8个区县25条中小型河道为研究对象,调查研究重金属在沉积物和水生植物中累积特征,采用潜在生态风险指数评价法对沉积物重金属污染进行了评价,采用生物富集系数(BCF)方法评价不同水生植物对重金属的富集特性,对水生植物与沉积物中的重金属含量进行相关性分析。分析表明,与土壤环境质量国家二级标准(GB15618-1995)相比,As、Ni和Zn平均含量是标准的6.7倍、1.5倍和1.4倍,Cd、Pb、Cu、Cr平均含量不超标。参照上海市土壤环境背景值,上海市中小型河道沉积物中7种重金属的潜在生态风险依次为：Cdgt;Asgt;Pbgt;Nigt;Cugt;Zngt;Cr,其中Cd、As生态风险严重,7种潜在生态风险Ri平均值为431.43,有强生态风险。植物体内累积最高的重金属为Cu,累积最低的重金属为Cd,沉水植物体内重金属Cd、As、Cr、Pb、Ni、Cu的含量均大于挺水植物,沉水植物苦草和水盾草对多种重金属的富集能力大于1,在重金属复合污染水体修复中具有较大潜力。根据植物体与沉积物中重金属的含量关系,发现黑藻与沉积物中重金属Cu、Ni、Pb的含量显著正相关;水盾草与沉积物中重金属Cu含量显著正相关,芦苇与沉积物中重金属Cr的含量显著正相关,上述3种植物可作为上海市河道重金属污染监测植物的选择对象。     

上海市中小型河道沉积物和水生植物中重金属累积特征研究

采用野外调查和室内分析相结合的方法,以上海市8个区县25条中小型河道为研究对象,调查研究重金属在沉积物和水生植物中累积特征,采用潜在生态风险指数评价法对沉积物重金属污染进行了评价,采用生物富集系数(BCF)方法评价不同水生植物对重金属的富集特性,对水生植物与沉积物中的重金属含量进行相关性分析。分析表明,与土壤环境质量国家二级标准(GB15618-1995)相比,As、Ni和Zn平均含量是标准的6.7倍、1.5倍和1.4倍,Cd、Pb、Cu、Cr平均含量不超标。参照上海市土壤环境背景值,上海市中小型河道沉积物中7种重金属的潜在生态风险依次为:CdAsPbNiCuZnCr,其中Cd、As生态风险严重,7种潜在生态风险Ri平均值为431.43,有强生态风险。植物体内累积最高的重金属为Cu,累积最低的重金属为Cd,沉水植物体内重金属Cd、As、Cr、Pb、Ni、Cu的含量均大于挺水植物,沉水植物苦草和水盾草对多种重金属的富集能力大于1,在重金属复合污染水体修复中具有较大潜力。根据植物体与沉积物中重金属的含量关系,发现黑藻与沉积物中重金属Cu、Ni、Pb的含量显著正相关;水盾草与沉积物中重金属Cu含量显著正相关,芦苇与沉积物中重金属Cr的含量显著正相关,上述3种植物可作为上海市河道重金属污染监测植物的选择对象。     

石鼓书院植物景观资源评价与保护

石鼓书院共有植物29科31属41种,主要植物景观类型5种.文章对评价指标进行量化,建立了植物景观评价指标体系,采用植物景观综合评价指数法和AHP法对石鼓书院槙物景观进行评价与分析.认为其植物景观资源整体水平偏低,植物景现质量为IIl级;对石鼓书院的植物景观恢复和保护提出了可行性建议.     

山西太原市综合公园植物多样性研究

城市公园绿地是城市园林绿地系统的主体,是集中体现城市植物多样性的场所,研究其植物多样性可为城市生物多样性保护提供基础。以山西太原市 17 个综合公园为研究对象,从植物应用的重要值、 Margalef 丰富度、Shannon-Wiener 多样性和 Pielou 均匀度分析其植物多样性,为太原市公园植物多样性保护及公园绿地建设提供参考。研究表明太原市综合公园的植物种类有 78 科 164 属 285 种。植物应用重要值排名前五的种类为大叶黄杨 > 紫叶小檗 > 圆柏 > 国槐 > 金叶女贞。植物丰富度指数为 26.42,乔木层 > 草本层 > 灌木层;多样性指数为 3.13,乔木层 >灌木层;均匀度指数为 0.60,乔木层 >灌木层。木本植物多样性总体评价较高的公园为汾河公园、玉门河公园和晋祠公园;较低的为映山湖公园、长风商务区大平台景观绿化、南海子公园。     

广东地区公园绿地海绵设施植物应用研究

在对广州、深圳和珠海公园普遍踏查的基础上,选取9个海绵设施应用较多的公园作为调查样地,针对应用的海绵设施类型、结构、规模、植物景观等进行实地调查分析。结果表明,公园绿地应用较多的海绵设施类型以植草沟、雨水花园和旱溪为主;海绵设施应用的植物有87种,隶属49科79属,以禾本科、豆科种类居多;海绵设施不同种植区域选择植物时应根据积水情况综合考虑植物的耐涝性;从海绵设施应用的植物种类及配置景观来看,雨水花园和旱溪最为丰富;最后,针对公园绿地海绵设施应用普遍存在的问题,分别从植物选择、景观配置及后期维护等方面提出建议。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.