广州市屋顶自然生长的植物

本文报道了广州市屋顶自然生长的植物种类调查结果,共记录维管植物49科109属128种.通过调查及分析,推荐16种有较好屋顶绿化潜力的物种.     

高度城市化地区既有建筑屋顶绿化建设潜力评析——以上海中心城区为例

广泛的屋顶绿化是改善城市生态环境的重要举措。为探求中国高度城市化地区屋顶绿化建设推广的可行途径,综述了国外先进国家的屋顶绿化建设历程以及针对既有建筑的拓展型屋顶绿化的建设难点,并以中国屋顶绿化发展较早的上海为例,对其中心城区（即上海市外环线以内的区域,总面积约667.80km2）既有建筑的屋顶绿化进行了适建性评估。国外屋顶绿化建设领先的国家大多经历了从鼓励到强制、从新建建筑到既有建筑的历程;针对既有建筑的拓展型屋顶绿化的建设更具技术挑战性,必须进行构造创新、基质优化、植物精选和成本控制;上海已率先发布屋顶绿化建设的强制性政策,相关技术研发已有相当基础,但推广建设类型仍有局限,拓展型屋顶绿化极具建设潜力。     

轻型屋顶绿化中景天属植物栽培基质配比研究

以国产泥炭、椰糠、珍珠岩、陶粒等为原料,进行不同配比的轻型屋顶绿化栽培基质配方研究,依据其理化性质,筛选出2种较适配方。以金叶佛甲草Sedum lineare ‘Aurea’等5种景天属植物为试材,对2种配比基质中扦插植株的生长效果进行比较,以筛选适于景天属植物屋顶绿化栽培基质。结果表明,除松塔景天S. nicaeense在2种栽培基质上生长差异不显著外,其余4种景天属植物均在配比为国产泥炭∶椰糠∶珍珠岩= 2∶3∶1的基质(F3)中生长旺盛,覆盖迅速,地上及地下部分生物量积累较大。因此,初步确定基质F3为适宜景天属植物生长的轻型屋顶绿化基质。     

8种轻型屋顶绿化植物种间竞争性研究

以8种常见的轻型屋顶绿化植物为试材,在不同厚度基质上采用随机混植模式配置,通过观测植物覆盖度和植被景观变化,分析不同植物种间竞争性。结果表明,松叶牡丹Portulaca grandiflora具有较强的侵占性,在构建多植物混植景观中宜慎用;垂盆草Sedum sarmentosum和黄花景天S.mexicanum具有较强竞争力和抗逆性,随着基质层厚度降低覆盖度占比增大;万点星S.acre和凹叶景天S.emarginatum竞争能力次之,在不同厚度基质层中覆盖度占比差异不大;玉吊钟Kalanchoe fedtschenkoi‘Rosy Dawn’、高景天S.kamtschaticum‘ellacombeanum’和棒槌玉莲S.nussbaumerianum匍匐竞争能力弱,适宜做竖向景观营建。综合考虑植被稳定性和建设成本,营建多样性轻型屋顶绿化植物景观选择基质层厚度10 cm为宜。     

城市屋顶绿化资源潜力评估及绿化策略分析——以深圳市福田中心区为例

屋顶绿化是现代城市改善生态环境条件,缓解高密度建成区人为活动负面影响的重要策略选择。以深圳市福田中心区为工作区,利用高精度遥感数据结合设计资料查询和实地调查构建基础数据源;在总结国内外研究成果的基础上,筛选适宜的屋顶绿化约束影响因子,构建资源潜力评估方法;对工作区进行城市屋顶绿化资源潜力评估和绿化策略探讨。结果表明:(1)建筑年代、承重结构、屋顶属性、屋顶小气候是城市屋顶绿化4个方面的主要适建要素,其所涵盖的建筑年代、建筑结构、屋面构造、屋顶功能、屋顶坡度、设备面积、建筑高度和遮荫状况等8个影响因子是决定城市屋顶绿化资源潜力的关键性指标;(2)把城市屋顶绿化纳入城市生态结构和功能建设的整体考虑中,积极开展资源评估、规划研究和配套管理政策建设是推进我国城市屋顶绿化发展重要任务;(3)深圳市中心区现状屋顶绿化率仅9%,剩余构筑物中有51%适合进行全部或部分屋顶绿化覆盖,今后应考虑采取强制、引导和鼓励等不同政策手段,选择适宜的绿化技术方案,对于现有以及正在建设的并且条件适宜的构筑物进行屋顶绿化。     

湿热地区简单式屋顶绿化的截流雨水效应

城市内涝是困扰各大城市的环境问题,其主观原因是来自迅速增加的城市不透水面.国外运用屋顶绿化作为截留雨水的措施得到广泛实践,而屋顶绿化滞留雨水能力随气候条件的变化而变化.湿热气候区具有气温高、湿度高、雨量大的气候特点,在此气候条件下探讨屋顶绿化截留雨水的效能具有重要意义.本研究以在夏季雨热同期的广州市为例,搭建3个简单式屋顶绿化测试平台,通过13个月试验期的气象观测和数据测定推算其截留雨水的效能.结果表明: 基质厚度30、50和70 mm简单式屋顶绿化的降雨滞留率分别为27.2%、30.9%和32.1%,平均峰值减少量为18.9%、26.2%和27.7%.广州市建成区面积1035.01 km²,屋顶面积约占37.3%,假设在此区域推行30 mm厚度基质的屋顶绿化,小、中、大雨的总迟滞比率分别为72.8%、22.6%和17.4%,以此推算得出可滞留雨水体积达14317×10⁴ m³,说明简单式屋顶绿化的截留雨水效应具有巨大潜力.本研究结果可为湿热气候区城市缓解城市内涝、建设海绵城市的构想提供参考.     

屋顶绿化低碳景观潜力探究

屋顶绿化作为一类城市人工生态系统,在其生命周期内展现出碳源/汇特征。然而,屋顶绿化碳作用机制复杂,目前缺少针对性的综合碳绩效量化方法和考核指标,阻碍了屋顶绿化城市脱碳的推广应用。着眼于屋顶绿化低碳景观潜力量化,本文分析了屋顶绿化系统内部碳循环机制,探究了生物碳汇、隐含碳、运行碳以及生物能源供给4条减碳增汇路径(P₁～P₄);基于碳排放归一化值和碳回收期双重绩效指标,总结了各减碳增汇路径归一化值测度方法;通过提取文献数据,量化了各减碳增汇路径的绩效潜力和特点。结果表明：路径P₁～P₄潜力量化值分别为9.54、-2.26、2.96、0.35 kg CO₂·m^-2·a^-1,各路径潜力受植物类型、气候等因素影响很大;此外,基础数据库不完善、评估情景异质对测度准确性产生了影响。对粗放型绿色屋顶综合低碳景观潜力进行分情景讨论,其生命周期(40年)综合减碳量在92.24～433.42 kg CO₂·m^-2...     

屋顶柱式无土栽培法

在屋顶用标准和简易型立柱分别组建树林式光合生产单位,种植番茄、番薯等,营养液浇灌,结果都生长良好.此法栽培技术可供屋顶绿化时参考.     

高度城市化地区屋顶绿化径流调控效益评价——以厦门岛为例

屋顶绿化的降雨径流调控效益对城市水安全与可持续发展具有重要作用,尤其是在土地资源紧缺与环境问题突出的高度城市化地区,然而目前针对城市尺度进行屋顶绿化降雨径流调控效益的研究较少。以厦门岛142 km~2的典型高度城市化地区为研究对象,采用ArcGIS与SCS-CN水文模型,研究了四种屋顶绿化实施场景在四种不同重现期(2、5、10、20年)降雨事件下各汇水区屋顶绿化的降雨径流调控效益,并依其空间分异特征制定差异化生态建设策略。结果显示,(1)平均地表径流减少率随城市屋顶绿化量的增加从0.91%增加至4.51%,随降雨强度的增加从2.86%下降到2.01%。屋顶绿化对南部城市核心区中山路商圈汇水区的地表径流削减作用最为显著,在2年重现期降雨事件和100%屋顶绿化实施场景下地表径流减少了8.84%。(2)厦门岛易积水区域主要分布在高崎机场、西北部港口、筼筜湖、五缘湾和环岛路;在四种屋顶绿化实施场景下,平均积水深度降低1.68、4.68、6.45、14.43 cm,平均积水面积减少6.11、16.89、23.29、52.06 hm~2,而随着降雨强度的增加,积水面积减少率幅度降低,屋顶绿化对中低...     

城市区域绿色屋顶普及对水量水质的影响

绿色屋顶是城市降雨径流管理的主要措施之一,为了解绿色屋顶普及对城市流域降雨径流量和径流水质的影响,本文以重庆大学虎溪流域为研究载体,评估了绿色屋顶规模化应用与流域降雨产流和径流水质的响应关系.结果表明： 在城市流域进行屋面绿化有助于消减降雨径流以及产污负荷,且屋顶绿化规模和空间分布情景影响降雨径流水质.在屋顶占城市区域总面积的比例为25%、降雨持续时间15 min、降雨强度14.8 mm·h^-1的条件下,当区域内屋顶全部绿化时,峰值降雨径流降低5.3%,降雨径流总量降低31%;总悬浮物（TSS）、总磷（TP）、总氮（TN）的污染负荷分别降低40.0%、31.6%、29.8%,峰值浓度分别降低21.0%、16.0%、-12.2%,平均浓度分别降低13.1%、0.9%、-1.7%;随屋顶绿化率的增加,TSS、TP浓度消减率有所提高,而TN浓度消减率则呈降低趋势,靠近流域总出水口进行屋面绿化,更有利于径流水质的改善.     

Mechanisms of roof plate formation in the vertebrate CNS

The roof plate is an embryonic organizing centre that occupies the dorsal midline of the vertebrate neural tube. During early CNS development, the roof plate produces secreted factors, which control the specification and differentiation of dorsal neuronal cell types. An appreciation of the signalling properties of the roof plate has prompted an enhanced interest in this important organizing centre, and several recent studies have begun to illuminate the molecular mechanisms of roof plate development.     

The different roles of the roof density and nest size in the Iberian magpie nest

Nest volume in magpies is modulated by sexual selection. However, density of material that compounds the nest could also affect sexual signalling, and we may expect that high-quality pairs build larger and denser nests, with these two variables being positively correlated. As found for nest volume, density of nest thatching should be negatively related with laying date, which is indicative of pair quality. Alternatively, these traits could be subjected to different selective pressures and, hence, indicate different qualities. Results of the present study on a population of magpies in the Iberian Peninsula showed no relationship between nest volume and roof density. However, roof density was positively correlated to laying date, so that those nests that are built at later dates tend to have denser roof material. These data support the theory that density of roof material is related to nest predation, as there is a greater risk of predation at the end of the breeding season. Thus, nest volume and roof density could be two independent elements of a magpie’s nest, which have different ecological roles, as they would be subjected to different selection pressures. I suggest that nest size is a predictor of parental quality as has been previously demonstrated, while roof structure (roof density) is related to predation risk.     

Patterning of the dorsal telencephalon and cerebral cortex by a roof plate-Lhx2 pathway.

The organizing centers and molecules that pattern the cerebral cortex have been elusive. Here we show that cortical patterning involves regulation of the Lhx2 homeobox gene by the roof plate. Roof plate ablation results in reduced cortical size and Lhx2 expression defects that implicate roof plate signals in the bimodal regulation of Lhx2 in vivo. Bimodal Lhx2 regulation can be recapitulated in explants using two roof plate-derived signaling molecules, Bmp4 and Bmp2. Loss of Lhx2 function results in profound losses of cortical progenitors and neurons, but Lhx2 mutants continue to generate cortical neurons from dorsal sources that may include the roof plate region itself. These findings provide evidence for the roof plate as an organizing center of the developing cortex and for a roof plate-Lhx2 pathway in cortical patterning.     

藏族生物人类学研究回顾

藏族生活在具有世界屋脊之称的青藏高原,特殊的生态环境和特殊的文化背景造就了藏族特殊的适应高原缺氧机制和体质特征,引起了国内外学者的广泛关注和浓厚的研究兴趣。本文从国内外数据库收集了492篇国内外杂志发表的关于藏族人类学研究方面的论文。通过统计、分析并结合我们的工作,初步回顾了30年藏族人类学研究,重点分析了藏族与汉族的族源关系。这些文献显示,从体质特征、血型、分子生物学和考古材料等方面都证明藏族是中华民族大家庭中不可缺少的的一员。本文最后展望了藏族生物人类学今后的发展。     

Precise tree-ring dating of building activities despite the absence of bark: A case-study on medieval church roofs in Damme,Belgium

A detailed dendrochronological survey was performed on the medieval roofs of the Church of Our Lady (CoOL) in Damme, Belgium. Seen its complex architectural history, special attention was paid to the identification of consecutive building phases, based on combined architectural historical research and tree-ring dating. In total 64 increment cores were taken throughout the roof structures of the CoOL. All roof timbers are made of European oak (Quercus robur/petraea), of which only few have surviving sapwood or bark. Tree-ring dating confirms the late 13th/early 14th century construction date of the roofs. For all chronologies that were composed, the highest correlation values are found with reference chronologies covering the catchment area of the river Meuse. From the dating results of the timbers of the CoOL it becomes clear that the same timber source was used for nearly a century. On several of the examined roof timbers, rafting joints were observed, demonstrating that the timbers were indeed tied together as a raft and floated down the river.By implementing sapwood estimates in a Bayesian chronological model (OxCal), tree-ring series with surviving sapwood from coeval roof structures were combined in order to narrow down the time range for the felling date. Based on the refined interpretation of the felling dates, several consecutive building phases can now be identified and dated, leading to a new interpretation of the architectural history of the CoOL. Intriguingly, a marked interruption in building activities is observed around 1300. Probably this is related to the instable political situation at that time, caused by the armed conflict that emerged between the Count of Flanders and the king of France. Since Damme served as the outport of the riotous city of Bruges, it was alternately seized by the French and Flemish, both consuming considerable amounts of timber and other building materials for military fortifications. Potentially this led to a shortage in building materials and provoked a stop in building activities.This paper demonstrates the power of Bayesian models to refine the interpretation of dendrochronological dates in architectural analyses of medieval historical buildings.     

绿色屋顶径流调控研究进展

绿色屋顶在屋顶径流调控方面发挥着重要作用,能够有效减少径流量、延缓产流时间、降低径流峰值和改善径流水质.本文从绿色屋顶的分类及界定、绿色屋顶对径流的调控机制、绿色屋顶对径流量和水质的调控作用及其影响因素等方面阐述了国内外的研究现状,并从绿色屋顶植物的选择、高效绿色屋顶构建模式筛选、绿色屋顶径流调控规律研究、绿色屋顶截流能力的价值评估、绿色屋顶径流污染物的源 汇解析及缓解措施等方面提出了绿色屋顶径流调控的研究趋势,以期为城市绿色屋顶的建设提供理论和方法支持.     

The subdivisions and fusions of the exoskeletal skull bones ofDiscosauriscus austriacus (Makowsky 1876) and their possible homologues in rhipidistians

Two localities in the Boskovice Furrow region of Moravia (Czecho-Slovakia) have produced new, well preserved material of the Lower Permian tetrapodDiscosauriscus austriacus (Makowsky 1876). A relatively large number of specimens have been found with some dermal skull roof bones partly or fully subdivided, and/or fused. These are the first records of such subdivisions and fusions in this tetrapod and the following bones are discussed: frontal, postfrontal, parietal, intertemporal, supratemporal, tabular and postparietal. The subdivided bones within the skull roof ofDiscosauriscus (and some dissorophoids) are situated at the same places as those found in Devonian rhipidistians, and may relate to the homology of the bones of the cranial exoskeletal roof inDiscosauriscus and in osteolepiforms. It shows that the “orthodox” terminology of the skull roof bones used in osteolepiforms is correct.     

Integrating cost-benefits analysis and life cycle assessment of green roofs: a case study in Florida

Abstract

Multiple environmental benefits can be achieved by using a green roof instead of conventional roofs. To better understand the LCA and cost-effectiveness of a green roof, a case study was performed. Two energy models, one with conventional white roof and the other with green roof, were created using eQUEST software to compare the influence of green roof on building energy consumption. The results indicated that the application of a green roof reduced annual space heating and cooling electricity consumption by 9500 kWh (2.2 kWh per square meter). The LCA shows that by using an extensive green roof in lieu of a conventional white roof the LCA measures at the product, construction, and end-of-life stages increased due to the use of additional layers. However, these increases are offset by the reduction of LCA measures at the use stage such that the overall environmental impacts of green roof is less than that of conventional roof. To find out the cost-effectiveness of green roof, a 50-year cost-benefits analysis was conducted. The analysis showed that the net savings of the green roof is negative compared to the white roof it replaced due to its higher initial cost and follow on maintenance cost.     

Regulation of cell polarity, radial intercalation and epiboly in Xenopus: novel roles for integrin and fibronectin

Fibronectin (FN) is reported to be important for early morphogenetic movements in a variety of vertebrate embryos, but the cellular basis for this requirement is unclear. We have used confocal and digital time-lapse microscopy to analyze cell behaviors in Xenopus gastrulae injected with monoclonal antibodies directed against the central cell-binding domain of fibronectin. Among the defects observed is a disruption of fibronectin matrix assembly, resulting in a failure of radial intercalation movements, which are required for blastocoel roof thinning and epiboly. We identified two phases of FN-dependent cellular rearrangements in the blastocoel roof. The first involves maintenance of early roof thinning in the animal cap, and the second is required for the initiation of radial intercalation movements in the marginal zone. A novel explant system was used to establish that radial intercalation in the blastocoel roof requires integrin-dependent contact of deep cells with fibronectin. Deep cell adhesion to fibronectin is sufficient to initiate intercalation behavior in cell layers some distance from the substrate. Expression of a dominant-negative beta1 integrin construct in embryos results in localized depletion of the fibronectin matrix and thickening of the blastocoel roof. Lack of fibronectin fibrils in vivo is correlated with blastocoel roof thickening and a loss of deep cell polarity. The integrin-dependent binding of deep cells to fibronectin is sufficient to drive membrane localization of Dishevelled-GFP, suggesting that a convergence of integrin and Wnt signaling pathways acts to regulate radial intercalation in Xenopus embryos.