内蒙古乌海民航机场鸟类多样性与鸟撞防范

为了开展鸟撞预防工作、减少鸟撞事故的发生,2009年8月-2010年7月,每月对乌海民航机场及其周围7种生境的鸟类进行调查,并分析了鸟类多样性指数.共记录到鸟类106种,隶属于16目37科,其中繁殖鸟78种,非繁殖鸟28种.依据重要值,并结合鸟类的分布系数和集群行为以及是否穿越跑道及跑道上空等因素,将调查记录到的106种鸟类划分为严重危险、很危险、较危险和一般危险4个等级.根据调查资料和吸引鸟类分布的主要环境因子分析,提出了乌海机场鸟撞防范对策.     

天津滨海国际机场鸟类群落结构及多样性特征

于2015年3月—2016年2月,采用固定半径样点法和样带法,对天津滨海国际机场飞行区内的鸟类群落结构及多样性特征进行了调查。结果表明:天津滨海国际机场分布鸟类12目31科52种,其中留鸟7种(13.46%),夏候鸟17种(32.69%),冬候鸟5种(9.62%),旅鸟23种(44.23%);广性分布鸟类8种,优势种6种;综合鸟类的飞行高度、体重、数量、遇见频率及生境利用率等因素对飞机飞行安全的影响,对鸟类危险等级进行了评估,严重危险鸟类有红隼(Falco tinnunculus)、喜鹊(Pica pica)和麻雀(Passer montanus)3种;秋季鸟类多样性指数最高,春季优势度最高,湿地苇丛的多样性指数和均匀度指数最高,场内建筑区的优势度指数最高,机场围界区与场内建筑区的鸟类群落相似度最高。通过对不同季节、不同生境鸟类多样性的对比分析,搞清机场飞行区内被鸟类利用的生境特征及鸟类分布与活动规律,进而为机场开展鸟撞防范工作提供依据。     

太原武宿国际机场鸟类多样性特征及鸟击防控

机场周边区域鸟类的活动给飞行安全造成了潜在的风险,掌握机场鸟类的多样性特征对开展鸟击防控工作有重要的指示意义。于2018年10月—2019年8月,采用样线法与网捕法对太原武宿国际机场飞行区与净空区进行了鸟类多样性调查。共记录到鸟类75种,隶属于13目31科,其中繁殖鸟占60%,非繁殖鸟占40%。用EstimateS软件对调查范围内鸟类丰富度进行估计,ACE值(81种),ICE值(98种),表明覆盖了调查范围内鸟类中76.53%～92.59%的物种,显示了较好的调查效果。为了明确所调查鸟类对鸟击防控工作的影响,根据这些鸟种的重要值(IV)与风险系数计算其危险指数。机场全年发生严重危险的鸟种有斑嘴鸭(Anas zonorhyncha)、家燕(Hirundo rustica)、绿头鸭(Anas platyrhynchos)、喜鹊(Pica pica)、环颈雉(Phasianus colchicus)、家鸽(Columba domestica)、珠颈斑鸠(Streptopelia chinensis)等10种。6种不同生境的鸟类群落多样性聚类分析表明:受人为干扰较大的生境类型为居民点和道路绿化带,其物种多样性较低(H=1.35±0.08);另外4种生境即机场草坪、水塘-滩涂、农田及人工林地受人为干扰较小,其物种多样性(H=1.66±0.04)较高。为此,在机场的鸟击防范工作中,要针对性地开展机场周边生态环境治理,制定靶向性的防控策略来应对危险鸟类在机场区域的活动。     

扎兰屯成吉思汗机场鸟类多样性与鸟击防范

机场及其周边鸟类种类调查及其多样性研究对于新建机场开展鸟击防范工作具有重要意义。2015年1—12月,采用样线法和固定半径样点法对内蒙古扎兰屯成吉思汗机场及其周边8 km范围内的区域进行鸟类多样性调查。调查期间记录到鸟类82种,隶属于15目31科。根据对鸟类的群落结构分析:机场围界内春季的鸟类多样性指数(0.740)和均匀度指数(0.819)最高;冬季的优势度(0.683)最高;夏季的平均密度(2.83 ind·hm-2)最高。机场围界外:夏季湿地的多样性指数最高,为1.576;冬季的草地均匀度指数最高,为0.902;冬季的居民区优势度最高,为2.113;春季的湿地平均密度最高,为28.60 ind·hm-2。本文综合鸟类的体积、数量、出现次数、飞行高度、与机场的距离、出现的样带数以及是否集群7个因子对鸟类的危险值重新赋值并计算得出危险值,严重危险鸟类有普通鸬鹚(Phalacrocorax carbo)、麻雀(Passer montanus)、赤麻鸭(Tadorna ferruginea)等14种。根据调查结果提出不同季节、不同区域以及不同鸟种的针对性防范意见以及机场管理对策,为今后扎兰屯机场鸟击防范工作提供科学依据。     

样线法和网捕法在机场鸟情调查中的应用比较

鸟击事件主要发生在机场范围内,对机场周边生境的鸟类组成进行调查,是制定鸟击防范对策的重要前提。国内多数机场已经开展了相关的鸟类组成调查,但是选用的调查方法却存在较大差异。以样线法和网捕法两种常用的调查方法对沈阳桃仙国际机场周边的迁徙期鸟类进行了研究,旨在比较两种调查方法在机场鸟类群落组成调查中的效果及调查的鸟类群落组成差异。结果表明：两种方法均适合机场鸟类调研,共记录到鸟类97种,网捕法记录的鸟类种数（83种vs.57种）高于样线法,网捕法单独记录的鸟类种数（40种vs.14种）也高于样线法。尽管两种方法每期（半个月）调查的物种数和目的数量无明显差别,但随调查强度（如调查次数）增加,网捕法累计记录到的鸟类种类明显高于样线法,且较晚达到渐近线。另外,两种方法调查记录的鸟类群落组成也具有显著的差别,如网捕法记录到较多鹌鹑和鸮形目等夜间迁徙或活动鸟类,而样线法可记录到鹭科和雁鸭类水鸟等。这说明两种调研方法在鸟类调查中有较好的互补性。因此,本研究认为机场鸟情调研时应该根据鸟情特点,选择合适的鸟类调研方法,综合采用多种调研方法可更有利于获得科学的鸟情信息。     

合肥新桥国际机场鸟类多样性及鸟击风险评价

鸟类多样性研究对于新建机场开展鸟击防范工作具有指导意义。2012年2月到2013年1月,采用样线调查法对新建合肥新桥国际机场及其周边地区鸟类进行了调查,根据鸟类相对数量、遇见频率、生境利用率和飞行高度,对机场鸟类鸟击风险进行评价。共记录到鸟类79种,其中留鸟34种,夏候鸟21种,冬候鸟和旅鸟分别为12种和11种;食虫鸟35种,食谷鸟8种,杂食性鸟15种,肉食性鸟21种。在各类生境中以林地的鸟类密度(D=10.25ind·hm-2)和Shannon-Wiener指数(H'=2.12)最高。全年以秋季鸟类密度(D=9.23ind·hm-2)、Shannon-Wiener指数(H'=2.13)最高。新桥机场鸟击风险高的鸟类共23种,飞行区内(R≥40)12种,飞行区外(R≥40)21种;其中留鸟占60%,食虫鸟占52%。加强对留鸟和食虫鸟的管理,采取生态防治和综合防治措施,对于降低机场鸟击风险具有积极意义。     

湖南常德桃花源机场鸟类的时空分布与鸟击防范

桃花源机场位于湖南省常德市鼎城区斗姆湖镇,距市区12.2 km.机场自1998年6月复航以来,鸟击事故时有发生,严重地影响到机场的飞行安全.为指导机场开展有针对性的鸟击防范工作,2008年5月～2009年4月,作者对桃花源机场净空区的鸟类群落组成和不同生境的鸟类物种多样性进行了实地调查,共记录到91种鸟类,隶属13目28科.其中留鸟39种,夏候鸟25种,冬候鸟25种,旅鸟2种.在不同季节中,机场净空区鸟类的Shannon-Wiener多样性指数和Pielou均匀性指数在春季均为最高,秋季均为最低.在净空区灌草丛、树林、农田、村落和水域5种鸟类生境类型中,以灌草丛生境鸟类的Shannon-Wiener多样性指数最高,村落生境鸟类的Pielou均匀性指数最高,农田生境鸟类的Shannon-Wiener多样性指数和Pielou均匀性指数均为最低.鸟类种群密度在灌草丛与农田、灌草丛与村落、灌草丛与水域、树林与农田、树林与村落、树林与水域、农田与村落、村落与水域生境之间的差异显著(P<0.05);灌草丛与树林生境、农田与水域生境间的差异不显著(P>0.05).鸟类种群密度在不同季节间的差异不显著(P>0.05).与鸟击的发生较为密切的鸟类为小云雀Alauda gulgula、牛背鹭Bubulcus ibis、金腰燕Hirundo daurica等鸟类.据此对桃花源机场的鸟击防范提出了相关建议.     

阜阳机场鸟类多样性及其危险性

2008年6月至2010年1月,对阜阳机场及其周围5种生境(草地、农田、城镇、湿地、林地)的鸟类进行调查,并对不同季节、不同生境的鸟类多样性进行分析.结果表明:本次调查共记录到鸟类122种,隶属于15目40科;阜阳机场夏、秋季的鸟类种数显著高于冬、春季,秋季鸟类密度显著高于其他季节,夏季的鸟类多样性指数、均匀度指数均高于其他季节;在阜阳机场及其周边的5种生境中,林地的鸟类种数、密度均显著大于其他生境,林地、湿地、农田的鸟类多样性较高;对阜阳机场鸟击最危险的鸟种是麻雀、白头鹎、家燕、家鸽、喜鹊、珠颈斑鸠、灰椋鸟等.     

新疆喀什机场净空区鸟害综合评估

为了解新疆喀什机场净空区鸟类群落特征,给机场鸟击防范提供数据支持,预防鸟击发生,2017年3月—2019年5月,采用样线法和样点法对净空区10个区域的鸟类群落进行了定期调查,并持续统计了跑道和滑行道两侧548张防鸟粘网的鸟情数据。结果共记录鸟类15目31科73种,其中,留鸟12种(16%),夏候鸟16种(22%),冬候鸟12种(16%),旅鸟30种(41%)和迷鸟3种(4%)。分布型以泛北方种(85%)为主,其中,北方广布种30种(41%)、古北型16种(22%)、全北型16种(22%)。多样性分析显示,春、夏、秋季的多样性指数高,冬季较低。而空地-杂草区、绿洲-农田区、城郊居民区、湿地-水库区、粮食储备库的多样性指数较高,垃圾场的较低。根据鸟类体质量、集群数量、遇见频率、生境利用率及飞行高度等对飞机的影响,对鸟害危险等级进行了评估:严重危险的是红隼Falco tinnunculus(38.78)、秃鼻乌鸦Corvus frugilegus(36.38)、凤头百灵Galerida cristata(25.45)和麻雀Passer montanus(25.50)。基于以上研究结果总结鸟情特点,各项分析指数(包括548张鸟网信息)依次为春秋夏冬,虽然冬季种类比较少,但一些种类的数量却比较大,需要提防。最后,为喀什机场鸟击防范提出合理化建议。     

功能、谱系多样性在机场鸟类群落研究中的应用——以扬州泰州国际机场为例

随着航空业的发展,野生动物与飞机之间的冲突愈发密集,机场鸟类群落多样性研究引起了大量关注。研究鸟类群落对生境类型的使用状况,可以掌握生境类型与鸟击风险的潜在关系,为机场环境改造提供理论依据。本研究于2019年7月至2021年11月,采用样点法对扬州泰州机场及周边8 km范围内的农田、湿地、林地和城镇4种生境中30个样点的鸟类群落进行调查。利用鸟类群落多样性指数,包括丰富度、多度、香农威纳多样性指数、辛普森多样性指数以及均匀度指数来表征群落的物种多样性,以及功能和谱系多样性,阐明机场周边4种生境的鸟类群落多样性差异。同时,基于多度加权的平均成对功能距离（MFD）和平均成对谱系距离（MPD）来表征群落的功能和谱系结构,探究群落构建机制,量化各多样性指标间的相关性。研究共记录扬州泰州国际机场鸟类88种,分别隶属于14目36科,目、科中数量最多的为雀形目（Passeriformes）和鹬科（Scolopacidae）。谱系和功能多样性在生境间差异显著,功能分散度在农田最高,城镇最低;谱系多样性指数在城镇最高,湿地最低。标准化效应值分析表明,随机生态过程影响了湿地鸟类群落功能和谱系的构建过程,农...     

Influence of storage methods on corn root length measurements

This study evaluated the changes in root length, mass, and diameter after air drying and rehydration of corn (Zea mays L.) root samples. For corn roots washed from soil, rehydrated root length was not reduced when compared with fresh root length, but rehydrated root mass was reduced to about half of fresh root mass, and rehydrated root diameter was approximately 75% of fresh diameter. Three storage methods (air dried, 70% ethanol, and 5% formaldehyde solution) were also compared for corn roots grown in moist paper towels. Although root mass and diameter were significantly reduced by air drying, root length was not altered by any of the treatments.     

Applications of functional classification methods for tree fine root biomass estimation: Advancements and synthesis

The morphology of fine root branching of woody plants is highly variable in their forms and functions. In the past two decades, researchers have increasingly recognized that the root-diameter-based method, using an arbitrary size of root diameter, failed to precisely characterize the physiological and ecological processes involved in finest roots. The number of publications using root-order-based approaches has increased regardless the fact that root trait-measurements based on root order are time-consuming and labor-intensive. A new approach—root functional classification method—was proposed and had been applied in the literature. The functional classification of fine roots separates roots of < 2 mm to absorptive and transport pools, making it more feasible for studies on root biomass and turnover. This new concept redefines fine root guild and has great potentials for future studies. Our literature review of the topic indicates that less is known about the inter-specific differences in estimates of biomass of absorptive and/or transport roots, with a large variation of absorptive roots on global scale. In addition, our review emphasizes the importance in: a) precision estimating of the absorptive biomass of fine roots, and b) proper definition of the range of the transport roots within and among forest ecosystems. Finally, after compare the strengths and weaknesses of the functional classification method, we propose several specific suggestions to improve the applications of this approach.     

Using a fine root extraction device to quantify small diameter corn roots (≥0.025 mm) in field soils

The study of fine roots growing under field conditions is limited by the techniques currently available for separating these roots from soil. This study had two objectives: to measure the total root length of field grown corn (Zea mays L.) by root diameter class, and to develop an inexpensive and efficient root washing device that would effectively capture all of the roots in a field soil sample. An inexpensive Fine Root Extraction Device (FRED) was constructed from readily available materials and was successful at extracting all roots, including very fine diameter roots (0.025 mm), from field soil samples. Greater than 99.7% of marked roots introduced to the FRED were recaptured by the device. Soil samples from three depths, and on three dates, from field grown corn were placed in the FRED. We found that more than 56% of total root length occurred in roots whose diameters were smaller than 0.175 mm, and more than 35% of root length occurred in roots smaller than 0.125 mm in diameter. Corn roots of the diameters described here have not been reported in field soils prior to this study. Root researchers who fail to measure these very fine roots will significantly underestimate root length density. Widespread use of the FRED should improve our understanding of root distribution in field soils.     

Root strength,growth, and rates of decay: root reinforcement changes of two tree species and their contribution to slope stability

Information on live root-wood strength, rates of root decay and root growth of both radiata pine (Pinus radiata D. Don) and kanuka (Kunzea ericoides (A. Rich.) Joy Thomps. var. ericoides) are combined to form a generalized conceptual model of changes in nett root reinforcement. The model provides an initial opportunity to rank the plant species having specific below-ground rooting habits that can be used to control erosion, and when linked with extreme flood probability can be used to indicate the risk of a storm likely to cause slope instability in the period between clear-felling and regrowth. Erosion-susceptible slopes planted 1 year after clearfelling in radiata pine at 1250 stems ha^-1 regain root site-occupancy in 4.7 years, an interval during which there is an 80% chance of experiencing an extreme flood. Similarly for radiata planted at 800 and 400 stems ha^-1, root site-occupancy is regained in 5.6 and 7.5 years, and the probability of occurrence of an extreme event within these periods is 85 and 90%, respectively. For erosion-susceptible slopes on which kanuka has become established, the probability of a significant event within the 2.8 years prior to root site-occupancy is 60%. Slopes felled of radiata pine are potentially more vulnerable to the stresses promoting slope instability, at least in the earlier years. This revised version was published online in June 2006 with corrections to the Cover Date.     

小麦种子根的发育解剖

小麦胚胎发育过程中通常形成5条幼根(少数可形成6条),这些根统称为种子根,中间最先发生的为初生根.初生根的原基在胚胎发育的早期就在胚轴的一侧发生,原基细胞由不规则到规则排列。侧生种子根的原基在胚胎发育后期才出现,通常成对发生,并且是由胚轴上的节(盾片节和胚芽鞘节)维管束外方的细胞形成。侧生种子根的发育明显较初生根的快,分化能力也较强,后生木质部导管母细胞出现早,数目较多.因此,小麦胚胎发育过程中从胚轴上形成的这些侧生的种子根,形态上,仍应看作是一些不定根,其结构特征与后来形成须根系的不定根的比较近似。     

The Developmental Anatomy of the Seminal Root of Wheat

Wheat embryo usually gives rise to five seminal roots in matured caryopsls, although, the sixth root might develop in some cases. The first one is known as the primary root. Primary root emerged early, and its primodium was distinctly originated from the proembryo and could be gradually identified as three layers of initials. Lateral seminal roots emerged later from the embryonic axis in pairs, and originated from the surrouding cells of the procambium. Differentiation of lateral roots was much more vigorous than that of the first seminal root (primary root), and, its mother cells of metaxylem vessel appeared soon, Lateral seminal roots usually had more metaxylem vessels. In short, only the first root is the primary root, the lateral seminal roots are adventitious in nature, since their structures are similar to those of other adventitious roots.     

Development and validation of a model to describe root length density of maize from root counts on soil profiles

Root length density (RLD) is an important determinant of crop water and nutrient acquisition, but is difficult to measure in the field. On a soil profile, in-situ counts of root impacts per unit surface on soil profiles (NI) can be used to calculate RLD if crop-specific parameters for preferential root orientation (anisotropy) are known. An improved method for field determinations of RLD was developed and validated for maize at sites in Côte d'Ivoire and Burkina Faso. Root anisotropy was measured with cubes of undisturbed soil with 0.1 m sidelength, based on NI observed on three planes oriented perpendicularly to each other. RLD was also measured for the enclosed volume. Repetition of such measurements enabled estimation of the robustness across sites of empirical and geometric models for the relationship between RLD and NI:RLD = NI CO, with CO being the coefficient of root orientation, theoretically equals 2 for an isotropic distribution. Root systems were found to be nearly isotropic, except near the root front (0.3 to 0.5 m), where roots had a preferentially orthotropic orientation. Measured RLD was generally about 50% larger than RLD calculated from observed NI and CO, indicating that at least one of the measurement techniques had a systematic error. The ratio between measured and calculated RLD (CE), which ranged from 0.8 to 2, increased with the age of the plants and decreased with soil depth. CE was therefore introduced as an additional coefficient, resulting in RLD = NI CO CE. The empirical value for CO CE was between 2 and 5. The empirical coefficients CO and CE were the same for the sites in Cote d'Ivoire (oxisol with an iron pan at 0.6 to 0.9 m) and Burkina Faso (alfisol with an iron pan at 0.4 to 0.8 m). The model was validated with independent data sets at both sites, and gave satisfactory predictions of RLD on the basis of NI obtained from single soil planes, which can be easily measured in the field.     

Linking root respiration to chemistry and morphology across species

Root respiration is a critical physiological trait involved in root resource acquisition strategies, yet it is less represented in root trait syndrome. Here we compiled a large dataset of root respiration associated with root chemical and morphological traits from 245 plant species. Our results demonstrated that root respiration correlated positively with root nitrogen concentration (RNC) and negatively with root tissue density (RTD) across and within woody and non‐woody species. However, the relationships between root respiration and specific root length (SRL) and root diameter (RD) were weak or even insignificant. Such root respiration–traits relationships were not completely in line with predictions by the root economics spectrum (RES). Furthermore, the principal component analysis showed that root trait syndrome was multidimensional. Root respiration was associated more strongly with the RNC‐RTD axis (the classical RES) than with the orthogonal SRL‐RD axis for woody species, but not for non‐woody species. Collectively, the linkages of root physiological, chemical, and morphological traits provide a better understanding of root trait covariation and root resource acquisition strategies.