黄龙山天然次生林辽东栎种群空间格局

种群的空间分布格局是研究种群特征、种间相互作用以及种群与环境关系的重要手段。为更好地了解黄龙山天然次生林内辽东栎(Quercus wutaishanica)的种群特征,在该林区中油松(Pinus tabulaeformis)-辽东栎-白桦(Betula platyphylla)天然次生混交林和辽东栎天然次生纯林内分别选取并设立1块1 hm2的样地。根据样地调查规范对两块样地中的乔木进行空间定位并进行每木调查。研究参照静态生命表,采用径阶替代年龄的方法,将辽东栎种群不同生长阶段的分段问题转换为根据胸径(DBH)的大小划分生长阶段。研究中将辽东栎划分为4个不同生长阶段:幼龄阶段A,3 cm≤DBH10 cm;中龄阶段B,10 cm≤DBH20 cm;近熟龄阶段C,20 cm≤DBH30 cm;成过熟龄阶段D,DBH≥30 cm。利用O-ring统计分析方法的手段,分析2块样地中辽东栎的种群空间分布格局。本次研究分别采用单变量、双变量分析方法分析各生长阶段的空间格局、不同生长阶段间相互关联性。结果表明:(1)辽东栎种群在两块样地内的径级结构均符合倒"J"型,从径级分布角度说明两块样地的天然更新状况都良好;(2)辽东栎的空间分布格局与尺度有密切关系,两块样地在大、中尺度水平上基本表现为随机分布,但是在较小尺度上均表现为聚集分布,在样地Ⅰ中0—6 m尺度上尤为突出;(3)同一样地内各生长阶段的空间分布格局不同,幼龄个体在小尺度均表现为聚集分布,在样地Ⅱ中0—11 m尺度上尤为突出;(4)样地中不同生长阶段间相互关联性也不尽相同,样地Ⅰ中各生长阶段间关联性均不明显;样地Ⅱ中,幼龄的个体与中龄的个体间在小尺度上表现出显著的正相关性,而与近熟个体和成、过熟个体在小尺度上表现为明显的负相关性。在2—5 m尺度上,中龄个体与成过熟个体也表现出一定的负相关性。辽东栎种群是黄龙山天然次生林重要的建群种之一,研究其不同生长阶段个体的空间分布规律有助于掌握黄龙山区辽东栎生长现状;研究不同生长阶段的空间关联性有利于深入了解其群落的发展趋势,并为对种群聚集性较大的区域开展结构化森林经营提供重要依据。     

不同群落蒙古栎种群空间格局的地统计学分析

以蒙古栎天然次生林中的蒙古栎种群为研究对象,在吉林省汪清林业局塔子沟林场设置2块1 hm^2的处于不同演替阶段的样地(A、B).采用相邻网格调查法将每块样地划分为100个10 m×10 m的调查单元,对单元内每株林木的空间坐标进行精确定位,调查所有胸径≥1 cm的林木基本信息.采用地统计学分析的半方差函数法和分维数对蒙古栎种群各林木属性的空间异质性程度、组成、尺度、方向进行分析;运用克里格插值法对具有空间自相关的树木属性进行无偏估计并绘制分布图,分析其空间分布格局.结果表明:两块样地各林木属性的最优半方差函数以指数模型和球状模型为主,呈聚集分布,但样地A较样地B的空间自相关程度更高,空间连续性更大;两块样地内部,胸径和东西冠幅均表现出较强的空间异质性和空间自相关性.两块样地各林木属性均在南北方向上表现出较强的空间异质性.此外,样地A在西北-东南方向上也存在较强的空间异质性,而样地B则在东北-西南方向存在较强的空间异质性.两者相比,样地A的空间异质性强度更高、尺度更大.样地A中胸径和东西冠幅变异明显,而样地B中东西冠幅和南北冠幅变异明显.分维数值反映的结果与标准半方差函数值的结果基本一致.样地A各林木属性变量以斑块状和条带状分布为主,空间分布格局和变化趋势明显,而样地B各林木属性变量分布破碎,格局复杂.上述结果说明,种群属性特征、群落发育程度、空间尺度大小和空间水平方向可能影响种群的空间格局.基于地统计学的分析方法有助于定量、直观地描述种群的生长现状和发展趋势,可为东北林区大面积的蒙古栎天然次生林的可持续经营提供理论基础.     

杉木与米老排人工混交林群落木本植物空间格局研究

该研究在全面踏查广西大青山实验场杉木-米老排人工混交林群落的基础上,采用典型样方法选择1块90 m×110 m的永久固定样地,测量每株活立木中心位置坐标,检尺每株活立木胸径(地径)、树高、冠幅等,并采用径级代替龄级和空间点格局分析方法的Ripley's L(r)函数,分析杉木-米老排人工混交林的种群动态以及群落内主要木本植物种群的空间分布格局和主要种群的种间关联,以探讨杉木-米老排人工混交林群落内物种间的相互作用以及保持种群稳定与演替规律,为亚热带人工混交林培育的树种选择、空间结构调整及抚育管理提供理论依据。结果表明:(1)样地内胸径≥1 cm的活立木共计49个树种、 3 361株,其中杉木、米老排、三桠苦、红椎、九节、对叶榕、水锦树7个树种重要值都在4%以上,占有较大优势,是林分的主要树种。(2)杉木-米老排人工混交林群落内所有活立木(DBH≥1 cm)在0～40 m的尺度上表现出聚集分布,其中:幼树(1 cm≤DBH5 cm)在0～40 m的尺度上的聚集程度较群落内所有活立木聚集程度高;小树(5 cm≤DBH10 cm)在0～5 m的尺度上呈现随机分布,在6～40 m尺度上的聚集程度较弱;大树(DBH≥10 cm)在小于5 m的尺度上表现出均匀分布,在5～40 m尺度上服从于随机分布。(3)群落内7个主要种群除米老排和红椎接近随机分布外,其他种群皆服从聚集分布,且随尺度增加聚集程度增强。(4)样地内大树与小树之间相互独立,而小树与幼树、大树与幼树之间在研究尺度范围内存在正关联关系。(5)研究区群落内主要种群(21个种对)之间以无关联和负关联为主,只存在少量种群(5个种对)之间呈正关联,表明广西大青山实验场杉木-米老排人工混交林群落结构的稳定性较弱,尚未达到群落演替的顶级阶段。     

浙江省典型天然次生林主要树种空间分布格局及其关联性

松阔混交林和常绿阔叶林是亚热带地区天然次生林代表性的森林类型,通过研究主要树种分布变动趋势,可以有效地指导森林经营措施。在该地区4个1hm~2典型样地,在0—30m尺度范围内综合分析了主要树种的空间分布格局及种间关联性,并对同一树种分发育阶段在不同森林群落中的种群空间分布格局进行了比较,以探讨亚热带地区天然次生林群落空间格局形成和种群维持机制。样地1和2为松阔混交林,其中样地1的马尾松密度较低,样地3和4为常绿阔叶林。研究结果表明:(1)以完全随机模型为零假设时,样地1的主要种群在小尺度(10 m)呈聚集分布,随尺度增加呈随机分布;样地2—4的主要种群在所有尺度呈聚集分布,随尺度增加聚集强度逐渐减弱;以异质泊松模型为零假设时,4个样地的主要种群在大部分尺度呈随机分布;(2)青冈和苦槠的小树(5.0 cm≤DBH10.0 cm)在4样地的所有尺度以聚集分布为主,大树(DBH≥10.0 cm)在松阔混交林样地呈随机分布趋势,但在常绿阔叶林样地青冈在0—20 m尺度、苦槠在所有尺度呈聚集分布;(3)松阔混交林中建群种马尾松和其他树种的种间关联性,在样地1的小尺度为负相关,随尺度增加为不相关,在样地2的所有尺度为负相关;常绿阔叶林中建群种青冈和其他树种的种间关联性在在样地3的小尺度为负相关,随尺度增加为不相关,在样地4的所有尺度为负相关;所有伴生树种的种间关联性以负相关为主。结果说明,种群空间分布格局及其关联性随群落结构和空间尺度的不同而出现变化,在松阔混交林和常绿阔叶林群落格局形成中除了扩散限制和生境异质性以外,密度制约机制在松阔混交林中发挥了重要作用,而在常绿阔叶林中其作用随着树木生活史阶段的提高而减弱。     

山西霍山白桦种群不同龄级立木的点格局分析

以山西霍山地区的先锋树种之一白桦( Betula platyphylla)为研究对象,在霍山七里峪林场典型地段设置一个50 m×50 m的样方,应用点格局分析方法对其不同龄级(Ⅰ级、Ⅱ级、Ⅲ级和Ⅳ级)个体的分布格局及相互关系进行了研究.结果表明:(1)白桦种群不同龄级的个体间密度也不相同,中间龄级Ⅱ级(7 cm＜ DBH≤14 cm)和Ⅲ级(14 cm ＜DBH≤21 cm)的密度较大,幼龄和老龄个体密度小,年龄结构为衰退型;(2)除Ⅰ级(DBH≤7 cm)外,其余3个龄级集群分布特征比较明显,且随着龄级的增加,集群特征有更明显的趋势;(3)除Ⅰ级和Ⅱ级、Ⅱ级和Ⅲ级、Ⅱ级和Ⅳ级(DBH ＞21 cm)之外,其余龄级间基本都是小尺度下负关联,并随尺度的增大关联性逐渐变得不显著.     

长白山蒙古栎次生林群落结构特征及优势树种空间分布格局

群落结构特征研究是揭示植物群落维持机制和演替动态的基础,是合理安排森林经营活动的基本前提.以吉林省汪清林业局2块1 hm²的蒙古栎阔叶混交林固定样地为对象,研究了长白山蒙古栎次生林的群落结构特征,并采用点格局O-ring统计法对群落内优势树种的空间分布格局进行分析.结果表明: 两块样地都是以蒙古栎为优势树种的群落类型,都具有明显的层次结构,主要伴生树种存在差异,样地Ⅰ以大青杨、白桦、红松为主,样地Ⅱ以红松、紫椴和色木槭为主.且样地Ⅰ的树种数量、Shannon多样性指数高于样地Ⅱ.两块样地中所有个体的径级分布呈倒“J”型,蒙古栎径级结构呈近似正态型,红松呈倒J型,其他主要伴生树种径级结构存在一定差异.两块样地0～50 m尺度上蒙古栎呈现小尺度聚集、中大尺度随机分布的格局,红松呈先聚集、后随机的分布格局,但样地Ⅰ内红松聚集的尺度和强度均大于样地Ⅱ.样地Ⅰ白桦和大青杨均在0～17 m尺度上呈聚集分布、且聚集强度显著高于其他树种,而在18～50 m尺度分别呈现随机分布和均匀-随机分布.样地Ⅱ中紫椴基本呈现随机分布,色木槭在中大尺度上呈随机或均匀分布,聚集分布集中在小尺度.两块样地处于演替早期阶段的不同发育阶段,相比样地Ⅰ,样地Ⅱ的演替阶段更高、群落相对更加稳定.     

北京东灵山暖温带落叶阔叶林枯立木与活立木空间分布格局

东灵山暖温带落叶阔叶次生林,是保存较完整的落叶阔叶次生林,其物种组成、群落结构是次生林演替过程的重要体现,也是下一步演替发生的基础。为了更好地研究其演替动态、生物多样性维持机制,以东灵山20hm~2样地为固定监测平台,分析了暖温带落叶阔叶次生林的活立木、枯立木物种组成、径级结构、空间格局。结果表明:(1)样地中DBH≥1 cm的活立木共有103702株,植株密度为5185.1株/hm~2;枯立木共有4543株,植株密度为204.9/hm~2二者均包括了分枝和萌枝的个体数。样地内DBH≥1 cm的活立木共有58种,分属于33属18科,DBH≥1 cm的枯立木共有33种,分属于23属15科。(2)活立木与枯立木整体分布随径级增大,均表现出先增大后减小的趋势,小径级个体多度在分布中优势显著。(3)活立木空间分布随径级增大,聚集强度减小,10 cm≤DBH20 cm、DBH≥40 cm此趋势明显,而20 cm≤DBH40 cm在0—50 m的尺度范围内,规则、随机、聚集分布均出现。枯立木的空间格局,DBH5 cm,DBH≥40 cm,尺度接近30 m时,随机分布;5 cm≤DBH40 cm,0—50m尺度范围内,聚集分布。空间分布格局显示了径级大小在空间分布上互补,不同径级的个体占据了样地内不同的生态位。(4)不同径级活立木与枯立木关联性分析表明,小径级小尺度,关联显著,大径级大尺度空间关联性逐渐减弱。枯立木的产生,是活立木受密度制约调控、演替地位及演替阶段、生境异质性等因素调控的结果,影响机制有待进一步研究。     

云冷杉天然次生林死木分布格局及空间关联性

为揭示天然次生林群落演替规律,以吉林省汪清林业局金沟岭林场的云冷杉天然次生林为对象,采用相邻网格法调查样地(100 m×100 m)内每株林木(DBH≥1 cm)的基本特征及坐标位置,研究死木的分布格局及空间关联性。结果表明: 死木的径级分布呈左偏单峰山状分布,其中枯倒木呈多峰山状分布;各树种的死木株数与该树种的总株数没有必然联系;树种死木株数与树种混交度之间存在显著负指数关系;死木主要在0～8 m尺度上呈聚集分布,随着尺度的增大,逐渐转变为随机分布或均匀分布,以随机分布为主;中(10 cm≤DBH＜20 cm)、小径级(1 cm≤DBH＜10 cm)死木在8 m以下的小尺度上的聚集分布是造成死木总体在小尺度上呈聚集分布的主要原因。不同径级死木与不同径级活立木的空间关联性差异较大,死木与幼树(1 cm≤DBH＜5 cm)的关系较为明显,尤其是大径级死木与幼树在2～25 m尺度上呈显著正关联性;死木与小树(5 cm≤DBH＜15 cm)没有明显的关联性;中、小径级死木与中树(15 cm≤DBH＜25 cm)在0～3 m尺度上呈正关联性,与大树(DBH≥25 cm)分别在9、11～14 m以及15、42～45 m尺度上呈负关联性。树种在生物学特性、径级分布和空间布局上的差异影响着死木的株数和径级分布;混交程度低的树种可能出现较多的死木;死木空间分布格局随林木径级和研究尺度的大小产生变化;死木与活立木的空间关联性在不同径级和不同尺度上呈现出明显差异。     

华北山地典型天然次生林群落的树种空间分布格局及其关联性

关帝山华北落叶松、云杉、杨桦天然次生林植被类型是华北高海拔地带代表性的森林类型。以该地区上述3种典型的天然次生林群落为例,运用点格局分析中的单变量O-ring统计方法,分析各群落主要树种的种群空间分布格局;用双变量O-ring统计方法,分析各群落中树种间的空间关联性;并对同一树种在不同森林群落类型中种群空间分布格局和种间关联性的变化进行比较,以探讨华北山地次生林群落空间格局形成和种群维持与动态机制。研究结果表明,(1)各种群在相对小的尺度上聚集分布特征明显,随尺度增加树木种群的聚集性减弱并逐渐表现出随机分布的格局特征;(2)同一树种在不同森林群落类型中空间分布格局差异很大。红桦、白桦和山杨在阔叶林中呈明显的小尺度聚集分布格局,而在针叶林群落呈随机分布。在阔叶次生林中混生的小龄级华北落叶松呈现聚集性空间分布格局。在华北落叶松为优势树种的针叶林中,大龄级的华北落叶松表现出小尺度上均匀分布和较大尺度上随机分布的格局特征;(3)各群落中树种间的空间关联性主要表现在小尺度范围,随尺度加大空间关联性逐渐不明显;(4)在阔叶树占优势的次生林,小龄级华北落叶松与桦木的分布有较明显的空间正关联性,而在华北落叶松为优势树种的针叶林,桦与华北落叶松并未表现明显的空间关联性。种群分布格局和种群间的空间关联性随群落结构、空间尺度和龄级结构不同而有较大变化。     

太岳山主要树种空间分布格局及其维持机制研究

该研究于2014年太岳山植被保护完好地区建立了CTFS技术规范的4hm2森林监测样地,调查并鉴定了样地内胸径(DBH)大于1cm的木本植物,分析样地内的群落组成,对样地中的主要乔木树种分为幼树(1cm≤DBH≤10cm)、小树(10cmDBH≤30cm)和成年树(DBH30cm)3个生长阶段,并在去除空间异质性的基础上,采用不规则区域中的点格局分析方法,定量分析样地中主要树种在0~100m尺度上的空间分布格局;用双关联函数^g(r)研究了种群不同生长阶段的格局类型,探讨太岳山主要树种的空间分布格局产生和维持的机理,以明确该区物种的生态适应对策和种群动态。结果显示:(1)样地内共有木本植物9 698株,其中包括枯立木209株;该区群落的主要优势物种为辽东栎(Quercus wutaishanica)、白桦(Betula platyphylla)、油松(Pinus tabulaeformis)、鹅耳枥(Carpinus turczaninowii)、野山楂(Crataegus cuneata)、色木槭(Acer mono)。(2)研究区主要树种以聚集型分布为主,加入枯立木后,种群聚集程度降低并趋于随机分布。(3)^g(r)函数分析表明,样地内种群不同生长阶段的个体呈现出随年龄增加聚集程度降低的规律,这种变化过程是对种群本身的生物学特性和环境条件的综合反应。研究结果初步确定,太岳山研究区存在一定程度的密度制约效应。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.