卧龙亚高山暗针叶林不同林冠环境下华西箭竹的克隆生长

该文调查了林下、中林窗、大林窗和林缘旷地等4种亚高山暗针叶林林冠环境下的华西箭竹(Fargesia nitida)分株种群,对其当年生立竹和母株的特征进行了比较研究,并探讨了母株年龄及大小对克隆生长的影响。主要研究结果如下:1)华西箭竹当年生立竹的分株密度以林下种群的最低,从林下→中林窗→大林窗,随林冠郁闭度的减小,华西箭竹基株当年生立竹的分株数逐渐增大。2)4种林冠环境下,当年生立竹和母株的分株高度、基径和生物量均有显著差异,且随林冠郁闭度的减小有递增的趋势(林下<中林窗<大林窗)。3)各林冠环境均以二龄母株产生的当年生立竹数量最大,不同林冠环境之间母株的平均年龄,以及处于同一林冠环境的各龄级母株产生的当年生立竹平均分株数和平均基径均无显著差异。4)不同林冠环境下,华西箭竹当年生立竹基径与一级母株、二级母株基径均呈正相关关系,但当年生立竹基径随一级母株增加的速度快于随二级母株的增加。5)当年生立竹的基径与地下茎直径呈显著的正相关;母株的基径与当年生立竹的地下茎直径呈正相关关系,而与其地下茎长度相关性不明显。     

中国亚热带高大竹类植物毛竹竹笋克隆生长的密度调节

对许多多年生克隆植物来说,大量的研究表明：当光是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小、死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明：竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加而增加。更确切地说,竹笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶（１龄叶）的成竹立竹度的增加而增加,而与带老叶（２龄叶）的成竹立竹度相关性不显著。并且竹笋的死亡率是非密度制约的。这可能是由于对毛竹来说,其立地总是比较开敞,而且,其竹笋的生长在很大程度上是不直接需光的。     

中国亚热高大竹类植物毛竹竹笋克隆生长的密度调节（英文）

 对许多多年生克隆植物来说,大量的研究表明：当光是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小、死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明：竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加而增加。更确切地说,竹笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶(1龄叶)的成竹立竹度的增加而增加,而与带老叶(2龄叶)的成竹立竹度相关性不显著。并且竹笋的死亡率是非密度制约的。这可能是由于对毛竹来说,其立地总是比较开敞,而且,其竹笋的生长在很大程度上是不直接需光的。     

中国亚热带高大竹类植物志竹竹笋克隆生长的密度调节

对许多多年生克隆植物来说,大量的研究表明：当是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小,死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明：竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加页增加。更确切地说,生笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶的成竹立竹度的增加而增加,而与老叶的成竹立竹度相关不显著。     

撑绿杂交竹和硬头黄竹克隆生长特性比较

以撑绿杂交竹(Bambusa pervariabilis × Dendrocalamopsis daii)和硬头黄竹(Bambusa rigida)为研究对象, 探讨了两种丛生竹生物量分配及克隆生长特性。结果表明, 硬头黄竹秆生物量比例显著高于撑绿杂交竹, 枝和叶生物量比例显著低于撑绿杂交竹, 硬头黄竹具有更高的养分同化效率。硬头黄竹与撑绿杂交竹的繁殖率无明显差异, 但其退笋率显著低于撑绿杂交竹, 表明硬头黄竹具有更高的繁殖效率。此外, 与撑绿杂交竹相比, 硬头黄竹的成竹根茎更长, 资源开拓性更强。两种丛生竹的新竹生长与母竹数量、大小和年龄结构具显著相关性。硬头黄竹产生的竹笋质量高, 具有较高的成竹率, 生长策略类似K对策; 撑绿杂交竹产生的竹笋数量多, 但退笋率较高, 类似r对策。硬头黄竹和撑绿杂交竹的成竹数(成竹胸径)与母竹数量(母竹胸径)间存在线性相关关系, 可以用线性模型模拟。     

模拟源株密度对蝴蝶花生长和克隆繁殖的影响

通过不同蝴蝶花(Iris japonica)起始源株密度的控制实验, 探讨源株对克隆植物蝴蝶花克隆繁殖、生长和生物量分配的影响。结果表明: 1)克隆数量特征: 1个起始源株处理(O)蝴蝶花新分株数显著高于2个起始源株(T)及4个起始源株处理(F), 而新分株死亡率显著低于后二者; 随着起始源株数增加(竞争增强), 一级与二级子株数显著降低。随着源株竞争增强, 克隆细根茎与根的长度、表面积、体积与根(茎)长密度逐渐降低。2)叶片特征: 随着源株竞争增强, 母株重度枯萎与总枯萎叶片数显著增加, 子株中度枯萎、重度枯萎与总枯萎叶片数显著增加; 源株竞争增强, 源株叶面积、源株与子株叶片数显著降低, 而源株叶面积比(leaf area ratio, LAR)显著增加。3)生物量及分配: 随着源株竞争增强, 细根茎、粗根茎、克隆繁殖、地上部分、地下部分及总生物量显著降低, 细根茎与地下部分分配降低, 母株粗根茎分配与地上部分分配显著增加。总的看来, 随着蝴蝶花源株竞争增强, 植株叶片生长状况受到更大的影响, 植株生长受限, 克隆繁殖减弱, 而其通过增加LAR, 提高叶片效率与增加母株粗根茎分配, 降低生长强度与消耗, 储备资源, 以待来年的生长与繁殖。     

不同密度下凤仙花重要形态性状与花朵数的关系

对30cm×30cm和50cm×50cm种植密度下的凤仙花(Impatiens balsamina L.)的地径、株高、冠幅、叶面积、花期、花径、一级分枝数、二级分枝数、一级分枝部位高和二级分枝部位高10个重要形态性状与花朵数的关系差异进行了相关性及通径分析,为凤仙花栽培与性状选择提供科学基础。结果表明:30cm×30cm种植的凤仙花的一级分枝数、二级分枝部位高都与花朵数呈显著正相关,地径、冠幅、二级分枝数与花朵数呈极显著正相关,对花朵数的直接效应大小顺序为:二级分枝数>一级分枝数>花径>花期;50cm×50cm种植的凤仙花,其地径、冠幅和二级分枝数都与花产量呈显著正相关,对花朵数的直接效应大小顺序为:二级分枝数>冠幅。二级分枝数对两种密度栽培的凤仙花花产量都起着重要作用。不同种植间距下凤仙花采用了不同的适应方式以获得最大花朵数目,进而获得最大数量的种子,获得较多的繁殖机会。在30cm×30cm下,是通过获得较多一级分枝数;在50cm×50cm下,是通过增加冠幅来产生较大花产量,而且与前者相比,植株茎秆粗壮,对霜霉病的抗性也强,因此,在栽培中,应以适合的低密度栽培比较好。     

采笋对大熊猫主食竹八月竹竹笋生长的影响

采笋是大熊猫栖息地内一种持续的人类干扰活动。为了评估采笋对大熊猫主食竹竹笋生长发育的影响,2009年7—11月,在四川省洪雅县瓦屋山镇设置实验样方,对比研究了早期采笋、中期采笋、晚期采笋、一直采笋和不采笋5种采笋方式对大熊猫主食竹八月竹竹笋生长和发育的影响。结果表明:1)早期采笋、中期采笋和一直采笋样方的发笋量显著高于不采笋样方(P0.05),其发笋量分别是不采笋的1.53倍,1.57倍和1.62倍;晚期采笋样方发笋量与不采笋样方差异不显著(P0.05)。2)早期采笋使八月竹在发笋早期和发笋中期的发笋量增加,中期采笋仅使八月竹在发笋中期的发笋量增加,而一直采笋使八月竹在整个发笋期的各个阶段的发笋量均显著增加(P0.05)。3)一直采笋样方的幼竹数量、株高均显著低于其他采笋样方,其基径只显著低于不采笋样方(P0.05);早期、中期、晚期采笋和不采笋样方相互间仅幼竹株高差异显著(P0.05)。4)早期、中期和晚期采笋与不采笋样方的发笋总量、退笋总量和采笋总量相互之间均呈显著正相关(P0.05)。建议仅在八月竹发笋中期采笋,同时政府应加大对大熊猫栖息地周边社区经济发展的引导和扶持。     

闽楠容器苗各器官生物量的分配格局及水分特征研究

以1.5年生闽楠(Phoebe bournei)容器苗为研究对象,揭示其在不同高度阶段各器官的含水率及生物量的分配格局,为闽楠的培育及利用提供理论依据。研究表明：①随着高度的增加,闽楠容器苗的生物量及各器官生物量也随之增加,各器官生物量分配大小表现为根生物量＞叶生物量＞茎生物量＞枝生物量;其中茎生物量分配随着高度的增加而增加,叶生物量分配则是随着高度的增加呈现先增加后减少的变化曲线,根生物量分配随着高度增加而先减少后增加。苗高与基径,树高、基径与叶、干、根、茎（干+枝）生物量以及地上、地下和单株生物量都具有极显著相关关系;树高、基径与枝生物量相关关系不显著;②高度为20~25 cm的闽楠幼苗其茎、叶的含水率达到最大峰值50%,其变化曲线相对比较平稳,而幼苗高度处于35~45 cm时根部含水率的最大峰值是61%,变化曲线振幅相对较大;③植株根含水率与茎、叶、地上生物量积累呈显著正相关,而叶含水率则与植物各器官生物量呈显著负相关。     

汶川地震对大熊猫主食竹——拐棍竹竹笋生长发育的影响

为了了解汶川地震对大熊猫主食竹生长发育的影响,2009年10月—2011年4月,在地震重灾区四川龙溪-虹口国家级自然保护区内设置150个样方,就地震强度、中度、轻度干扰对大熊猫主食竹拐棍竹(Fargesia robusta)竹笋生长发育的影响进行了研究。研究结果显示:(1)发笋物候上,地震强度干扰的发笋时间(Julian时间)较中度和轻度干扰显著推迟,而发笋期不受影响。(2)发笋量和当年生幼竹数是拐棍竹更新生长的数量指标。地震强度和中度干扰样方的发笋量都显著高于轻度干扰,而发笋量在强度和中度干扰间差异不显著;地震强度干扰样方的当年生幼竹数显著高于中度和轻度干扰,中度和轻度干扰样方间差异不显著。这说明地震的强度和中度干扰都有利于拐棍竹竹笋和当年生幼竹数量的更新。(3)基径和株高是拐棍竹更新生长的质量指标。强度干扰下拐棍竹的基径和株高都显著小于中度和轻度干扰,中度干扰样方的基径与轻度干扰差异不显著,但株高显著矮于轻度干扰样方。表明强度干扰下拐棍竹的质量最差,中度干扰的基径已基本得到恢复,但株高仍受到抑制。(4)地震不同干扰等级拐棍竹退笋原因划分为:外力机械损伤、动物取食、生长停止、其他4种。对地震不同干扰等级拐棍竹退笋原因比率的分析发现,强度干扰样方因外力机械损伤和生长停止退笋的比率显著高于中度和轻度干扰样方,而因动物取食退笋的比率显著低于中度和轻度干扰样方。证明强度干扰样方的竹笋更容易受到外力机械损伤和生长停止退笋,而中度和轻度干扰的竹笋更倾向于动物取食致退,揭示了拐棍竹的生长是与震后不同程度的干扰相适应的。     

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.     

Clonal plant allocation to daughter ramets is a simple function of parent size across species and nutrient levels

The evolution of clonal growth is a widespread phenomenon among plant species, characterized by the production of genetically identical clonal fragments (ramets) via rhizomes or stolons that form an interconnected clonal organism (genet). Clonal plant species are known to differ in their investment into ramet production, and exhibit considerable variation in ramet morphology both within and among species. While patterns of resource allocation are thought to be linked to a number of plant characteristics, many analyses are limited by uncertainty in how clonal plants determine the morphology and resources allocated to new ramets. In this study, we attempted to discern what aspects of parent ramets best predicted resource allocation to new daughter ramets, and the relationship between resource allocation and daughter ramet rhizome morphology. We grew two sedge species, Schoenoplectus tabernaemontani and Eleocharis elliptica, in a greenhouse under two levels of fertilizer addition. By harvesting daughter ramets that had initiated stem production, yet remained aphotosynthetic, we were able to isolate parental investment into non-independent daughter ramets at a point where daughter ramet spacer length became fixed. Our results indicate that parent ramets allocated a non-linear proportion of parent rhizome biomass to the production of daughter ramets. Moreover, this relationship was unaffected by environmental nutrient availability. Daughter ramet biomass, in turn, was strongly correlated with daughter ramet spacer length. These observations shed light on key processes governing clonal growth in plants, and their potential application in unifying allocational and morphological perspectives to explore the fitness implications of variability in clonal growth.     

慈竹构件和分株水平总黄酮含量的变化

黄酮类化合物是植物体内重要的次生代谢物质之一。本文采用AlCl3 比色法测定了慈竹构件和分株水平总黄酮含量的变化 ,以探讨其生理生态适应性。结果表明 ,在地上 3个构件中 ,叶的总黄酮含量显著大于枝和秆 ;1龄分株叶的总黄酮含量显著大于其它 4个龄级 ,而枝和秆的含量在 5个年龄间无显著差异 ;分株上层叶和枝条的总黄酮含量显著多于中下两层的相应构件。叶龄对慈竹叶总黄酮含量有显著的影响 ,1龄、 7龄和 9龄叶片的总黄酮含量明显高于其它 6个龄级 ,但是叶龄和总黄酮含量之间无显著线性相关。同时 ,叶总黄酮含量对季节的变化敏感 ,2、 4和 12月含量最高 ,5月和 8月含量最低。在分株水平 ,1龄分株的总黄酮含量显著大于其它 4个龄级。这些结果说明慈竹的总黄酮含量对环境变化具有可塑性 ,分株水平与叶构件水平总黄酮含量对分株年龄的反应格恐相同。     

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.     

慈竹构件和分株水平的可溶性糖含量研究

采用蒽酮比色法,测定了克隆植物慈竹构件和分株水平的可溶性糖含量．以探讨其对环境的生理适应性．结果表明,在构件水平,可溶性糖含量以慈竹叶最大,枝条次之,秆最小．不同构件的可溶性糖含量对分株年龄和分株部位的反应格局不同,1龄分株枝和秆的可溶性糖含量较高,而分株年龄对叶的可溶性糖含量影响不显著;分株下层叶和秆的可溶性糖含量大于上中层．高光条件下1龄分株叶的可溶性糖含量显著高于弱光条件下的1龄分株．叶可溶性糖含量受季节影响显著,1月最低,4月最高．但2龄和3龄分株间差异不显著．母分株和子分株上、中两层叶可溶性糖含量呈显著正相关,而下层相关性不显著．在分株水平,慈竹5个龄级间的可溶性糖含量无显著差异．总之,慈竹可溶性糖含量受生物和非生物因子的影响显著,且分株和构件层次存在差异．     

Partial mechanical stimulation facilitates the growth of the rhizomatous plant Leymus secalinus: modulation by clonal integration

Background and Aims

Mechanical stimulation (MS) often induces plants to undergo thigmomorphogenesis and to synthesize an array of signalling substances. In clonal plants, connected ramets often share resources and hormones. However, little is known about whether and how clonal integration influences the ability of clonal plants to withstand MS. We hypothesized that the effects of MS may be modulated by clonal integration.

Methods

We conducted an experiment in which ramet pairs of Leymus secalinus were subjected to three treatments: (1) connected ramet pairs under a homogeneous condition [i.e. the proximal (relatively old) and distal (relatively young) ramets were not mechanically stressed]; (2) connected ramet pairs under a heterogeneous condition (i.e. the proximal ramet was mechanically stressed but the distal ramet was not); and (3) disconnected ramet pairs under the same condition as in treatment 2. At the end of the experiment, we harvested all plants and determined their biomass and allocation.

Key Results

Clonal integration had no significant influence on measured traits of distal L. secalinus ramets without MS. However, under MS, plants with distal ramets that were connected to a mother ramet produced more total plant biomass, below-ground biomass, ramets and total rhizome length than those that were not connected. Partial MS exerted local effects on stimulated ramets and remote effects on connected unstimulated ramets. Partial MS increased total biomass, root/shoot ratio, number of ramets and total rhizome length of stimulated proximal ramets, and increased total biomass, root weight ratio, number of ramets and total rhizome length of connected unstimulated ramets due to clonal integration.

Conclusions

These findings suggest that thigmomorphogenesis may protect plants from the stresses caused by high winds or trampling and that thigmomorphogenesis can be strongly modulated by the degree of clonal integration.     

莲草直胸跳甲取食对空心莲子草和莲子草克隆整合的影响

很多外来入侵植物都具有克隆生长习性,探究克隆整合特性与外来克隆植物入侵性间的关系对阐明其生态适应性及入侵机制具有重要的意义。本研究以入侵植物空心莲子草及其本地同属种莲子草为研究对象,比较在生防昆虫莲草直胸跳甲的取食下,克隆整合对两种植物先端分株、基端分株及整个克隆片段生长和生物量分配的影响。结果表明: 在莲草直胸跳甲取食下,有克隆整合的空心莲子草先端分株的叶片数、茎长、分株数及整个克隆片段的地径均显著高于无克隆整合植株,其基端分株及整个克隆片段的地下生物量和总生物量相较于无克隆整合植株分别降低了78.2%、60.9%和48.7%、37.2%;有克隆整合的莲子草先端分株的地径及整个克隆片段的叶片数与无克隆整合植株相比显著增加,其基端分株数显著降低了21.7%,而其先端分株、基端分株及整个克隆片段的生物量均无显著差异。耗益分析表明,在莲草直胸跳甲取食下,空心莲子草先端分株的分株数与生物量及莲子草先端分株的分株数均能通过克隆整合显著受益,而两种植物基端的分株数、生物量的耗益则不受克隆整合处理的影响。这些结果表明,克隆整合虽能在一定程度缓解莲草直胸跳甲对于两种植物先端分株的取食压力,且空心莲子草的克隆整合作用要强于莲子草,但在整个克隆片段水平上,两种植物并不能通过克隆整合显著获益。     

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.     

Integration in the clonal plant <Emphasis Type="Italic">Eriophorum angustifolium</Emphasis>: an experiment with a three-member-clonal system in a patchy environment

A clonal plant in heterogeneous environments is usually expected to profit from resource exchange via a clonal network where ramets placed in contrasting environments can specialise so to acquire the most abundant resources. An experiment was designed using the three member clonal system of Eriophorum angustifolium, which consisted of one parent ramet growing in a resource poor environment and two offspring: one was limited in growth by nutrients while the other was light limited; the contrast in availability of limited resources between the offspring ramets was high, medium or none, with the system either connected or severed. The total resource availability was the same in all treatments. We proposed four possible scenarios for the system: offspring ramets will share resources via the deficient parent ramet, and the whole clone will profit from the contrasting environment (scenario 1); offspring ramets will support exclusively the parent ramet, and the whole clone will profit from a homogeneous environment (scenario 2); offspring ramets will stop the export of the limiting resource to the parent ramet, with split and connected treatments not differing (scenario 3); and offspring ramets will exhaust the carbon stored in the biomass of the parental ramet; offspring ramet will profit from connection (scenario 4). In the experiment, the limiting resources were sent to the strongest sink (scenario 2). The parent ramet growing in a deficient environment received the highest support in the treatment where both offspring ramets were growing in the same conditions (no-contrast treatment). Production of new shoots, but not biomass of whole clone, was supported in a homogenous environment. The experiment revealed that multiple stresses might prohibit free exchange of limiting resources via the clonal network and supports the idea that experimental studies on more complex clones are essential for understanding the costs and benefits of clonal growth.