松嫩平原杂类草草甸和榆树疏林草原大油芒种群的年龄结构

对松嫩平原杂类草草甸和榆树疏林草原上大油芒种群的年龄结构及各龄级构件的物质生产力和营养繁殖力进行了研究.结果表明:在2003和2006年中,2个生境的大油芒种群分蘖株均由2～3个龄级组成,根茎由4个龄级组成,分蘖株和根茎均以1a和2a所占比例最大,年龄结构呈增长型或稳定型;分蘖节芽以1a或2a者占优势,根茎顶端芽在芽库中所占比例为29.4%～45.0%,对翌年种群的更新具有重要作用;分蘖株、根茎的物质生产力和营养繁殖力均以1a或2a构件最大,根茎比分蘖节具有更旺盛的营养繁殖力.     

松嫩平原人工草地野大麦无性系构件的生物量结构及生产规律

野大麦属短根茎丛生型禾草,是典型的无性系植物．在松嫩平原生长季末期。野大麦无性系分株由抽茎的分蘖株和莲座状分蘖苗组成．按照分蘖节营养繁殖世代的龄级划分方法,建植2年人工草地野大麦无性系的分蘖株由3个龄级组成,分蘖苗由4个龄级组成,其生物量均呈增长型的龄级结构．在野大麦无性系的物质生产中,无论是分蘖株,还是分蘖苗,均以1龄级的单蘖生产力最高,并随着龄级的增高呈不同程度的下降．丛径是衡量野大麦无性系空间大小的重要数量指标．分株数量是衡量野大麦无性系生长的重要数量指标．经统计分析,野大麦无性系的分蘖株生物量、分蘖苗生物量、根茎生物量、总生物量分别与丛径和总分株数量之间均有极密切的正相关关系,其相关程度最佳的均为幂函数,其相关性均达到极显著水平(P<0．01)．这些相同的函数变化表明,随无性系的空间扩展和数量增长,各构件具有相同的物质生产与积累规律．     

松嫩平原杂类草草甸阿尔泰狗哇花无性系种群构件年龄结构

阿尔泰狗哇花为根蘖型菊科多年生无性系草本植物.采用主根芽区的繁殖世代数划分分株和芽龄级的方法,研究了松嫩平原杂类草草甸阿尔泰狗哇花无性系种群不同构件的年龄结构.结果表明:分株构件和芽构件均由4个龄级组成.在孕蕾期,分株构件中1龄级占22.6%、2龄级44.8%、3龄级28.8%、4龄级3.8%,呈稳定型年龄结构.在乳熟期,生殖分株构件以2龄级比重最大,占45.6%,4龄级最小,占0.8%,为稳定型年龄结构;而营养分株构件以1龄级比重最大,占47.5%,4龄级最小,占1.1%,为增长型年龄结构.分株主根的生活年限最多为5年.不同生育期分株构件的生产力均以2龄级最高.在乳熟期,1龄级分株具有较大的生产潜力,4龄级分株的生产力已普遍减弱.芽库中潜在种群呈增长型年龄结构.     

松嫩平原全叶马兰种群无性系分株的建成及其年龄结构

全叶马兰（Kalimeris integrifolia Turcz.)为根蘖型多年生草本菊种植物。在生长季后期,新生肉质细根向地表生长形成根蘖芽,根蘖芽成株后形成主根。经过对大量样本观察。创建了按形态特征对根蘖型草本植物种群无性系分株和芽的年龄划分方法,以及对主根生活年限的估计方法。分株年龄是按主根芽再生的次数划分,新根蘖芽成株为1a,1a分株死亡后从主根再萌生的分株为2a,2a分株死亡后从主根再萌生的分株为3a。新根蘖芽为0a芽,其它龄级与分株的龄级相一致,即1a分株主根芽为1a芽,2a分株主根芽为2a芽,在松嫩平原割草草场,全叶马兰种群由3个龄级无性系分株组成,呈稳定型年龄结构。分株主根的生活年限最多为4年,分株的生产力种群水平以2a最高,个体水平以1a最低,并随着龄级的增加呈增长趋势,其中,在生长季初期以3a分株的生产力最高,进入中期以后则1a最低,并随着龄级的增加呈增长趋势。其中,在生长季初期以3a分株的生产力最高,进入中期以后则1a分株的相对生长速率最大,用秋末新生根蘖数量和现时种群数量可以较准确预报翌年种群数量和年龄结构。芽库中潜在种群数量是现时种群数量的2倍以上,但不意味着种群将发生疯长,而是为替补所做的充分准备。     

松嫩平原全叶马兰种群无性系分株的建成及其年龄结构

全叶马兰(Kalimeris integrifolia Turcz.)为根蘖型多年生草本菊科植物.在生长季后期,新生肉质细根向地表生长形成根蘖芽.根蘖芽成株后形成主根.经过对大量样本观察,创建了按形态特征对根蘖型草本植物种群无性系分株和芽的年龄划分方法,以及对主根生活年限的估计方法.分株年龄是按主根芽再生的次数划分,新根蘖芽成株为1 a,1 a分株死亡后从主根再萌生的分株为2 a,2 a分株死亡后从主根再萌生的分株为3 a.新根蘖芽为0 a芽,其它龄级与分株的龄级相一致,即1 a分株主根芽为1 a芽,2 a分株主根芽为2 a芽.在松嫩平原割草草场,全叶马兰种群由3个龄级无性系分株组成,呈稳定型年龄结构.分株主根的生活年限最多为4年.分株的生产力种群水平以2 a最高,个体水平则以1 a最低,并随着龄级的增加呈增长趋势.其中,在生长季初期以3 a分株的生产力最高,进入中期以后则1 a分株的相对生长速率最大.用秋末新生根蘖数量和现时种群数量可以较准确预报翌年种群数量和年龄结构.芽库中潜在种群数量是现时种群数量的2倍以上,但不意味着种群将发生疯长,而是为替补所做的充分准备.     

扎龙湿地不同生境芦苇种群根茎构件的年龄结构

芦苇是典型的长根茎型克隆植物,天然种群主要依靠根茎的营养繁殖进行更新。采用单位土体挖掘取样,按实际生活年限划分根茎龄级的方法,对扎龙湿地芦苇种群不同龄级根茎进行调查。结果表明,6月份,4个生境芦苇种群根茎构件均由2—6a的5个龄级组成,7—10月份均由1—6a的6个龄级组成。6—10月份,1a根茎长度比率逐渐增加;除盐碱生境略有增加外,其他3个生境2a、3a比率均小幅减少;4—6a比率逐渐减小,根茎长度比率均以3a最大,依次是2a,4a,1a,5a,最高的6a最小。1—3a根茎生物量比率逐渐增加;4—6a比率逐渐减小,均以3a根茎生物量比率最大,依次是4a,2a,5a,6a,以最低1a最小。不同龄级根茎长度和生物量比率与返青后实际生长时间之间均较好地符合直线函数关系(R~20.91,P0.01;R~20.81,P0.05),6—9月份,根茎长度呈衰退型年龄结构,10月份又转为稳定型结构,整个生长季根茎生物量均为衰退型结构。不同龄级根茎构件在芦苇种群中的地位和作用不同,根茎构件的年龄结构蕴含着种群调节的重要信息。     

松嫩平原人工草地野大麦无性系冬眠构件的结构及形成规律

野大麦属短根茎丛生型禾草 ,是典型的无性系植物。在松嫩平原 ,野大麦无性系的冬眠构件是由冬眠芽和冬眠苗组成。按照分蘖节营养繁殖世代的龄级划分方法 ,在生长季末期 ,野大麦无性系的芽库由 5个龄级组成 ,苗库由 4个龄级组成 ,均呈增长型的龄级结构。苗库对潜在无性系的贡献将远远大于芽库。结合建植时间估计 ,人工草地野大麦的分蘖节最多存活了两个年度 ,分蘖节在一个生长季最多可繁殖 4个世代。野大麦无性系的根茎芽数、分蘖节芽数、总芽数、总苗数、总冬眠构件数均随着丛径、丛面积和亲株数量的增加呈幂函数形式增长。野大麦无性系冬眠构件各组分具有相同的形成规律 ,但在形成过程中则存在着不同的生态可塑性。     

松嫩平原赖草无性系生长及其构件的年龄结构

赖草是长根茎型禾草,是典型的无性系植物．在松嫩平原栽培条件下,移植第1年的赖草无性系,经过一个完整生长季的营养繁殖,最多可形成215个分蘖株,在4个取样的无性系中,最大的无性系是最小的5．4倍;经过2个完整生长季最多可形成2852个分蘖株,最大为最小的2．7倍．在无性系整体水平上,2个年度间无性系扩展面积平均增长了13．2倍,分蘖株平均增长了13．3倍,根茎的累积长度平均增长了15．9倍,根茎节数平均增长了11．2倍,根茎生物量平均增长了14．7倍．无性系分蘖株由2个龄级组成,呈增长型年龄结构,并且随着无性系的生长,其增长型年龄结构更为明显．无性系的芽库均由3个龄级组成,亦呈增长型年龄结构,但随着无性系的生长,其增长型年龄结构趋于减缓．赖草无性系以形成大量的根茎顶端芽和根茎节间芽发育成分蘖株,实现无性系空间生态位的扩展和持续更新．     

松嫩平原栽培条件下羊草无性系构件的结构

羊草是长根茎型禾草,是典型的无性系植物,在松嫩平原的生长季末期,栽培条件下羊草无性系分株由分蘖株和分蘖苗组成,在具有充分生长空间而又没有种间竞争的风沙土上,羊草分株的分蘖节在一个生长季内可以繁殖4个世代,按分蘖节的繁殖世代划分龄级,现实与潜在无性系构件的年龄谱均以1龄级比重最大,随着龄级的增加明显减少,呈增长型的年龄结构,羊草无性系分株的生产力主要与分株形成及生长的时间长短有关,形成时间越早、生长时间越长的分蘖株对无性系的物质生产和营养繁殖的贡献越大,羊草无性系在空间扩展与物质贮存上具有一定的可调节性。     

松嫩平原水淹恢复演替过程中羊草无性系种群构件的年龄结构

对松嫩平原羊草草甸水淹恢复演替过程中不同大小羊草无性系斑块的种群构件年龄结构进行了研究。结果表明 ,羊草种群分蘖株在斑块中心由 4个龄级组成 ;最外圈层由 3个龄级组成。根茎在斑块中心和中间圈层均由 2～ 4个龄级组成 ,最外层由1～ 2个龄级组成。潜在种群冬性苗和分蘖节芽总量各圈层均由 4个龄级组成。斑块中心的分蘖株种群为稳定型年龄结构 ,向外发展至增长型年龄结构。根茎长度和潜在种群在各圈层均呈增长型年龄结构。在水淹羊草草甸的恢复过程中 ,不同大小羊草无性系斑块均呈不断扩展的趋势。在生存空间充足时 ,羊草的分蘖节在一个生长季里可以繁殖多个世代。通过羊草根茎的年龄结构可预测演替的进程     

扎龙湿地芦苇种群不同龄级根茎构件的季节动态

克隆植物根茎具有营养繁殖和扩展种群的功能,也是芽和分株生理整合的通道。根茎构件具有出生、死亡及年龄等种群统计特征,不同龄级根茎的季节动态可以反映根茎的存活和衰老过程。采用单位土体挖掘取样,对扎龙湿地4个生境芦苇种群根茎构件进行野外调查,比较不同龄级根茎长度、生物量和干物质贮量的季节动态。结果表明:7—10月份,1a根茎长度、生物量和干物质贮量均呈指数函数增加,在生长季中后期有一个持续时间较长的生长和物质积累时期。6—10月份,2a、3a根茎长度呈线性函数增加,4—6a根茎长度呈线性函数减少;2—4a根茎生物量和2—5a根茎干物质贮量呈二次函数先减少后增加,5a、6a根茎生物量和6a根茎干物质贮量呈幂函数减少。整个生长期内,根茎长度和根茎生物量均以3a最大,根茎长度以最高的6a最小,根茎生物量以最低的1a最小;根茎干物质储量以5a最大,以最低的1a最小。4个生境芦苇种群根茎长度、生物量和干物质贮量在龄级间的差异及差异序位稳定,在新根茎的产生、老根茎的存活以及根茎寿命与养分消耗和储藏上均具有稳定的生物学特性,不同龄级根茎在种群中的地位和作用以及对种群的贡献不同。     

Patterns of Solidago altissima ramet growth and mortality: the role of below-ground ramet connections

Summary For the rhizomatous perennial, Solidago altissima, I identified clonal fragments in the field, mapped ramet spatial locations, and documented patterns of ramet recruitment, growth, and mortality. Parent ramet size influenced the size and number of daughter ramets produced, and small ramets had lower survivorship and fecundity than large ramets. Similarly, small rhizomes tended to develop into small ramets, and ramets that survived to produce daughter ramets had longer parent-daughter rhizome connections than ramets that did not survive. In addition, most ramets that died during the growing season were connected to (genetically identical) ramets that persisted. There were large size inequalities among rhizomes, ramets, and clonal fragments. Inequalities in the size of ramets increased during the early part of the growing season, then decreased at the end of the season; similar patterns were observed for the growth of clonal fragments. In both instances, the decrease in size inequality could be attributed to the mortality of small individuals (ramets or clonal fragments). I found little evidence that ramet size hierarchies were structured by intraspecific competition. For example, path analyses and randomization tests indicated that size variation among S. altissima ramets was influenced little by the size of their near neighbors (but was influenced by parent size and rhizome size). In addition, within-season variation for the relative size and growth rate of individual ramets led to poor correlations between early and final ramet size; this result suggests that there was no stable hierarchy of dominant and suppressed ramets. I discuss implications of my results for contrasting interpretations of clonal plant population dynamics.     

新疆伊犁河谷平原狗牙根无性系构件的生长

采用随机挖掘整个无性系的方法,在新疆伊犁河谷平原2年无人工管理的葡萄园撂荒地,对狗牙根无性系进行了大样本取样,定量分析了构件生长的规律.结果表明：在30个狗牙根无性系中,分株数平均为（272.6±186.6）个,其中营养分株占总分株数的82.3%,是生殖分株的4.3倍;无性系总生物量为(45.4±40.0) g,其中根茎占总生物量的54.4%,营养分株占21.0%,匍匐茎占14.8%,生殖分株占9.4%;根茎与匍匐茎的累计长度分别为(5.1±4.7) m和(3.3±3.4) m、着生的芽数分别为(291.5±246.8)和(78.8±87.4)个.根茎和匍匐茎芽数与无性系的营养分株、生殖分株、根茎和匍匐茎的数量性状之间均呈极显著的正相关关系(P<0.01),表明在新疆伊犁河谷平原,狗牙根无性系主要以根茎芽实现其持续更新.     

Internal heterogeneity of ramet and flower densities of <Emphasis Type="Italic">Typha angustifolia</Emphasis> near the boundary of the stand

Fifteen relatively narrow stands of Typha angustifolia, including both stands bounded to open water and ridged boundary, were investigated in terms of the distributions of ramet density as well as the fraction of flowering ramets. The ramet density, fraction of flowering ramet and morphological characteristics of ramets were measured continuously from one side of the stand to the other, together with depth and the nutrient concentration of pore water. The rhizome biomass was also measured at the periphery and at the center of the stand. The results indicated that the shoot density declined gradually from the edge to the center, however, the fraction of the flowering ramets were significantly higher at the edge while it rapidly declined away from the edge. Statistical analyses indicate that the ramet density depends on either depth or nutrient level of the pore water; however, the distance from the edge was the most probable factor to reduce the fraction of the flowering ramets. The rhizome biomass was mostly larger at the periphery than at the center, likely because the accumulation of the horizontal rhizomes as extension was blocked by the boundary. High flowering fraction near the periphery was probably induced by the hormonal change caused by the blockage. However, a large fraction of ramets flowered simultaneously with large rhizome biomass at the periphery, likely because of the preferable light climates compared with inside the stand.     

Clonal plasticity in response to rhizome severing and heterogeneous resource supply in the rhizomatous grass Psammochloa villosa in an Inner Mongolian dune, China

In a field experiment, Psammochloa villosa plants were subjected to rhizome severing. Severing rhizomes reduced growth in the young, detached rhizome segments compared to the controls in terms of all measured clonal growth-related characters, i.e. number of rhizomes and shoots, total rhizome length and total number of rhizome nodes. In a container experiment, the control ramets received uniform water and nutrient supply but in heterogeneous treatments high and low levels of water and nutrient supply, respectively were established. The number of ramets, total rhizome length, dry weight per ramet and biomass allocation to the rhizome had higher values at high water and nutrient supply, while spacer length (length of rhizome between shoots) and rhizome internode length were not affected. The local response of ramets given low water supply was enhanced due to connection to a well watered parent ramet in terms of number of ramets, total rhizome length and dry weight per ramet. A remote effect was not observed in the other treatments or in the other measured characters.     

松嫩平原全叶马兰种群不同龄级分株的生长策略

全叶马兰为根蘖性多年生草本菊科植物,种群由3个龄级无性系分株组成,在松嫩平原6月份,是全叶马兰营养生长的旺盛期,研究结果表明,分株的生长与生产力以1龄级最低,2、3龄级依次增高,3个龄级分株的生物量分配均为茎>叶>主根,叶的生物量分配为1龄级>2龄级>3龄级,茎和主根的均为1龄级<2龄级<3龄级,3个龄级分株总重与分株高度、分株叶重与茎重、分株主根重与枝条重之间均为幂函数异速生长规律,主根的生物量分配则随着分株高度的增加呈线性减少,全叶马兰无性系分株的生长与分配策略是在分株幼小时将较多的物质分配给叶,以保证物质生产器官叶的建造上,随着分株生长逐渐将生产的物质分配到茎和主根的生长与贮藏;分株不向主根投入较多的能量,但在分株幼小时向主根中分配的物质相对较多,随着分株的生长则按比例较小,并保持相对稳定的分配比率     

EFFECTS OF FIRE ON CLONAL GROWTH AND DYNAMICS OF PITYOPSIS GRAMINIFOLIA (ASTERACEAE)

The rhizomatous perennial Pityopsis graminifolia was studied in a Florida sandhill community in an annually burned site, a periodically burned site, and a site that has been protected from fire since 1965. These different fire regimes significantly affected the demography and life histories of both plants and plant parts in this clonal species. Fires resulted in reductions in ramet biomass and height, and an increase in the (root + rhizome)/shoot biomass ratio. Burning also decreased the total number of flower heads and new rhizomes produced per ramet. However, the survivorship of initiated rhizomes was greater in burned sites and resulted in a larger number of established daughter ramets per clone. As a result, in burned sites there was a shift in clone structure toward larger numbers of smaller ramets, but there were no significant reductions in seed or rhizome production on a per genet basis. The results showed that the responses to fire in P. graminifolia are different when measured at the genet vs. ramet level and that the effects of fire on clones can be explained by demographic responses of plant parts. Population regeneration in the study sites was dependent on successful clonal ramet production because no seedling recruitment was observed. This suggests that disturbances other than fire are important for new genet recruitment in these clonal populations.     

扎龙湿地不同生境芦苇种群根茎数量特征及动态

采用单位土体取样,计测长度和生物量的调查与统计方法,对扎龙湿地保护区4个生境芦苇种群根茎数量特征进行比较分析。结果表明,芦苇5月10日左右返青后进入营养生长期,根茎长度6—8月份缓慢增加,8—10月份显著增加,后期是前期的3.5—10.3倍,生长季中后期是种群新根茎补充和生长的主要时期,不仅实现了种群空间扩展,并为营养繁殖储备更多繁殖芽;根茎生物量和干物质贮量6—8月份逐渐减少,8—10月份又逐渐增加,均以生长季末期的10月份最大,并均显著地(P0.05)高于其他月份,种群根茎养分的消耗主要供给根茎芽的萌发和幼株生长,根茎养分的储藏又为翌年种群的更新及扩展提供物质保障,种群对地下根茎存在明显的养分"超补偿性"贮藏现象。种群根茎长度和生物量均以湿生生境最大,依次为旱生生境、水生生境,盐碱生境最小,根茎干物质贮量以旱生生境最大,依次为湿生生境、水生生境,盐碱生境最小。种群根茎长度与返青后实际生长时间之间均较好地符合直线函数关系,种群根茎生物量和干物质贮量与生长时间之间较好地符合二次曲线函数关系,R2在0.804—0.997之间,拟合方程均达到了显著或极显著(P0.01)水平。4个生境芦苇种群在根茎长度、生物量、干物质贮量等数量特征均表现出由遗传因素控制的比较稳定的季节动态规律,在生境间的差异及其差异序位又均基本稳定,均表现出明显的土壤因子环境效应,其中土壤含水量、有机质、速效氮为正向驱动,p H、速效磷为负向驱动,土壤含水量、p H对根茎数量特征的驱动作用更突出。