【作者】 郑维列；

【导师】 田大伦；

【作者基本信息】 中南林业科技大学 ， 生态学， 2010， 博士

【摘要】 长鞭红景天之分类地位属于景天科、红景天属、四裂红景天组、长鞭红景天系,该系共有9种(国产8种),具有独特之生活型——地上芽植物和矮高位芽植物,红景天属其它种类全部为地面芽植物和地下芽植物。作为高寒草本植物,长鞭红景天之矮高位芽植物生活型无疑是非常特殊的。可以通过主轴上花茎环之数量判断植株的存活年龄。作者对海拔4150-4680 m(山顶)范围内7个群落类型：急尖长苞冷杉林(P1)、方枝柏疏林(P2)、薄毛海绵杜鹃灌丛(P3)、毛叶小垫柳矮灌丛(P4)、鳞腺杜鹃灌丛(P5)、硬叶柳灌丛(P6)及小舌紫菀亚灌丛群落(P7)之长鞭红景天数量特征进行了研究。平均密度大小顺序为：P3>P1>P2>P4>P6>P7>P5、平均基径大小顺序为：P6>P2>P7>P5>P4>P1>P3、平均高度大小顺序为：P6>P2>P7> P5>P1>P3>P4、平均花茎数多少顺序为；P6>P7>P2>P1>P3>P5>P4、平均花茎环数多少顺序为：P7>P6>P5>P2>P1>P3>P4、平均分枝数多少顺序为：P6> P1>P3>P2>P4>P7>P5、重要值大小顺序为：P5>P7>P4>P3>P2>P1>P6。总体上幼体数量少、成体和老体数量相对较多。种群大量繁殖周期为11-15年。各生长参数与基径级呈正相关。幼年阶段生物量积累主要存在于地下部分。成年之后由于主轴年生长约1.5cm、生物量年增加约0.5g,肉质根逐渐腐烂,新生之不定根生物量水平较低,致使生物量根冠比减小。养分的生产与存贮,繁殖活动都完全依赖于主轴的生长。个体地上部分生物量与海拔高度之间无相关性,但阳坡>阴坡。种群的空间分布格局总体上呈现为聚集分布与随机分布的临界状态、偏向聚集分布。长鞭红景天生态位宽度值最大,其余大部分优势种的生态位宽度值差异不大,各优势种群在群落中分布广且较为均匀。各种群对资源竞争趋势较不明显,对资源共享趋势较明显；长鞭红景天与大多数种群的生态位重叠值较高,但相互间并不存在较为剧烈的竞争。长鞭红景天种群密度与海拔高度无相关性。调查地典型种群总体的平均密度为1.37株·m-2。长鞭红景天种群在海拔4640m处地上部分生物量最高,达到96.60 g·m-2。其地上部分生物量差异非常大,最大相差690倍(海拔4640m阳／海拔4570m阴)；即使在相同坡向条件下亦能达到138倍(海拔4640m/海拔4520m),但其变化与海拔高度无关。种群地上部分生物量平均值1.90g·m-2(已将极大值96.60 g.m-2剔除)可作为较客观的资源量计算依据。各器官生物量在总生物量中所占比例总趋势为主轴>叶>花茎>果。主轴占绝对优势,阳坡种群占73.2%,与阴坡种群占59.3%,其变化与海拔高度无相。阳坡种群之果生物量与种群密度、种群地上部分生物量呈极显著正相关,与灌木盖度、乔木灌木总盖度呈显著负相关。阴坡种群之果生物量与环境因子相关不显著。阴坡种群较阳坡种群更趋向于衰老。长鞭红景天27.79%的遗传变异存在于居群之间,72.21%的遗传变异存在于居群内。长鞭红景天种子属于强迫休眠类型。原生境人工播种繁殖失败。发芽过程不受变温、恒温条件影响。20-25℃是长鞭红景天种子发芽的最适宜温度,与高寒尘境条件不匹配。作者推断其起源于低海拔地区,目前仍处于选择适应阶段。长鞭红景天的单纯生殖力明显高于毛小叶垫柳(生于同一区域的高山植物,雌雄异株,地上芽植物),但其维持种子休眠的能力却远低于垫柳。长鞭红景天种子的萌发和幼苗的生长受到其它物种制约。在其幼苗的生长过程中,急尖长苞冷杉、硬叶柳和锦丝藓水浸提液对其抑制作用均达极显著水平,雪层杜鹃达到显著水平,而长鞭红景天对自身幼苗的影响不明显。通过对生长期内季节性MDA、SOD、POD、CAT、AsA、叶绿素和类胡萝卜素、渗透调节物、UV-B辐射保护物质等的追踪测定,表明低温和UV-B辐射是长鞭红景天之高寒胁迫因子。低温是其重要的胁迫因子。UV-B辐射复合低温胁迫因子的作用效果也非常明显。但长鞭红景天应激系统各成分存在相互补偿机制,种群已具有较强的抗逆性。长鞭红景天的根际微生物之根际效应非常显著,存在着大量的根际促生细菌和菌根菌。长鞭红景天只有两性花和雌花,没有雄性花。两性花的结实率极低(仅为2.85%),两性花仅执行雄性花功能。资源限制是长鞭红景天生殖成功的主要限制因素,表现在立地条件上。长鞭红景天生殖潜力较大,但生殖力较小；从花蕾到种子的形成生殖过程中,花蕾损失率为61.5%,开放花朵的损失率50.2%,胚珠损失率89.6%,与海拔高度无明显相关性。长鞭红景天种群花期为30天左右,6月下旬开始开花,7月下旬结束。雨季开花降低了传播距离。光照因子影响开花进程。两性株花期(9.29天)大于雌性株花期(7.06天),且先于雌性株开放。雌性花的开花高峰期先于两性花的开花高峰,利于降低花粉限制。单株花期与花数显著正相关,与始花期显著负相关。雌株始花期与花数、花期、结实量明显相关。开花同步性指数与结实量的相关性显著,但与始花期不相关。单株花期、始花期是影响结实量和种子产量的主要因子。单果平均种子数为14.6个,单株平均种子产量的估计值为228.6个。长鞭红景天属于典型的阳性偏强阳性植物；海拔4470-4520m是其最佳适生区域；海拔越高更新速度越慢。11-20年龄段是种群主体(在普遍情况下占56%),多为营养繁殖个体。具有实生苗个体特征的植株仅出现在1-3年龄段和极少数4-10年龄段中。在更新调查中1-3年生实生苗占80.6%,4-10年龄段占0.9%,实生苗更新严重阻断。近60%的个体成功实现营养繁殖,是长鞭红景天种群更新的主要途径。长鞭红景天对高寒生境有一定适应,人为采挖主轴是其最大威胁。其繁衍策略是：以营养繁殖为基础,最大限度地保持种群数量稳定；以极少量的种子繁殖为机会,脆弱地维持种群质量的稳定与提升。属于渐危种。藏东南长鞭红景天主轴资源总量为146.41×104t。作者提出的保护措施是：严格控制采挖量；加大生物反应器生产技术研究投入,努力降低生产成本；加大迁地保护之驯化研究投入,争取获得能正常生长且有效物质含量较高的商品主轴。更多还原

【Abstract】 The taxonomic status of Longwhip Rhodiola (Rhodiola fastigiata) is at Ser. Fastigiatae, Sect. Chamaerhodiola, Rhodiola, Crassulaceae. There are 9 species in the Ser. Fastigiatae, and 8 species are distributed in China. They have unique life form/chamaephyte & nanophanerophyte. The life form of others from Rhodiola is hemicryptophyte & geophyte. It is very special that Longwhip Rhodiola’s life form is nanophanerophyte as herbaceous psychrophyte. The plant live age can be identified by scape ring’s quantity in caudex.Longwhip Rhodiola’s quantitative characters have been researched at 7 types of community, they are fir forest(P1), juniper open forest(P2), rhododendron shrubs(P3), procumbent willow brushwood(P4), rhododendron dumi(P5), willow shrubs(P6) and subshrub thicket(P7) in altitude 4150～4680 m. The average density range is P3>P1>P2>P4>P6>P7>P5. The average basal diameter range is P6>P2>P7>P5>P4>P1>P3. The average height range is P6>P2>P7>P5>P1>P3>P4. The scape quantity range is P6>P7>P2>P1>P3>P5>P4. The scape ring quantity range is P7>P6>P5>P2>P1>P3>P4. The branch quantity range is P6>P1>P3>P2>P4>P7>P5. The importance value range is P5>P7>P4>P3>P2>P1>P6. The young is lesser, adult and agedness is major on the whole. The population reproduces in large quantities with periods about 11～15 years. Various growth parameters are positive correlation with basal diameter grade.The biomass in juvenile phase accumulates at underground part mainly. After they became to maturity, the biomass root-canopy ratio changed shrunken with that annual increment of caudex length is round about 1.5cm, annual increment of biomass is about 0.5g, while the fleshy roots perished gradually and regenerative adventitious roots possessed minuscule biomass. Production and reserve of nutrient, still including breeding activity depend on the growth of caudex. Individual biomass of overground part has not any pertinence to altitude, but sunny place is greater than shady place.Spatial distribution pattern of Longwhip Rhodiola population shows conjoint state between aggregated distribution and random distribution in the mass, but it approached to aggregated distribution.The niche breadth of Longwhip Rhodiola is most, and of the other dominant species has small difference. In the community, each dominant species distribute evenly and widely. Among the populations, competition is invisible and sharing is obvious to resources. The niches overlap highly between Longwhip Rhodiola and the most of other populations, but there is not intense competition among them.The population density has not any pertinence to altitude. The average density is 1.37 one·m-2 by typical population in investigation zone.The population biomass of overground part is the most/96.60 g·m-2 at 4640m. Its changes have not any pertinence to altitude, but the discrepancy is very large that the most multiple is 369 times (sunny 4640m/shady 4570m), and is 138 times at same slope aspect(sunny 4640m/sunny 4520m). The average population biomass of overground part is 1.90g·m-2 (without 4640m’96.60 g·m-2) as impersonal data with resources appraisal. Biomass proportion of each apparatus shows caudex>leaf>scape>fruit. The caudex predominates absolutely with 73.2% at sunny place,59.3% at shady place, and their changes have not any pertinence to altitude. The population biomass of fruit at sunny place shows the most distinct positive correlation to population density and biomass of overground part, and shows distinct negative correlation to coverage of shrubs and trees. The population biomass of fruit at shady place has invisible pertinence to E-factor. The population at shady place is more senescent than at sunny place.Genetic variation’ 27.79% is among the associations, and 72.21% is in the associations.The seeds of Longwhip Rhodiola pertain to enforced dormancy type. It has been unsuccessful that was by artificial seeding in situ. Germinant process is not conditioned by mutative and constant temperature. Its most suitable temperature is at 20～25℃, incompatible to arctic-alpine habitat. Author deduced that Longwhip Rhodiola was traceable in the lower altitudes, and is in a selected or adaptive phase at present. Its simplex fecundity is higher distinctly than Salix pilosomicrophylla, which is a kind of dioecism/chamaephyte/psychrophyte at same habitat with Longwhip Rhodiola, but dormant ability of seeds is lower greatly than Salix pilosomicrophylla.Seeds germination and seedling growth of Longwhip Rhodiola are restricted by other species. The inhibiting effect attained very conspicuous level through the growing process of seedlings, from which the inhibitor was respective water extracts of fir, willow and moss, and. it attained conspicuous level from water extracts of Rhododendron. It is not conspicuous that Longwhip Rhodiola affects itself seedlings.According to the regular mensuration at MDA, SOD, POD, CAT, AsA, chlorophyll, carotenoid, osmoregulatory matter, UV-B protection parasites, the results show that low temperature and UV-B is arctic-alpine stress factor to Longwhip Rhodiola, low temperature is an important stress factor, the compound with UV-B and low temperature has conspicuous threatening effect. However, there is a complementary mechanism among the various compositions in Longwhip Rhodiola’s stress-response system, and its population has been provided with a strong resistibility.The effect of rhizosphere microbe is highly significant, and there are a mass of PGPR and mycorrhizal fungi.Longwhip Rhodiola possesses hermaphrodite flowers and female flowers only, do not male flower. The ripening rate of hermaphrodite flower is very low (only 2.85%), and they only officiate the function of male flowers. The main limiting factor of its reproductive success is resource limited that is reflected at the site condition. It has large reproductive potential but small fecundity, and the loss rate of buds is 61.5%, of inflorescent flowers is 50.2%, of ovules is 89.6% during the process from buds to seeds, these changes have not obvious pertinence to altitude.The florescence of its population is about 30 days with starting in late June and ending in late July. The illumination affects abloom process. Hermaphroditic’s florescence (9.29 days) is greater than gynoecious’s (7.06 days), and hermaphroditic blossom out earlier than gynoecious. The peak period of gynoecious’s blossom out was earlier than of hermaphroditic, that this is propitious to reduce the pollen limiting. The florescence of a single has distinct positive correlation with flowers quantity, distinct negative correlation with early blooming. The early blooming of gynoecious has distinct pertinence with flower quantity, florescence and fruit yield. The index of abloom synchrony has distinct pertinence with fruit yield, but has not any pertinence with early blooming. The florescence of a single and the early blooming is main factor for fruit and seed yield. It is 14.6 that are the average quantity of seeds in a fruit, the estimated value of seed average yield in a plant is 228.6.Longwhip Rhodiola is representative heliophyte (in favor of high heliophyte), the best normal region lie in 4470～4520m, and its growing speed was decreased by altitude increasing.11～20 years age group is main body of the population at prevalent state that they seize hold of 56% and almost of them come from vegetative propagation. The plants which they own the character of seed propagation only present to 1～3 years age group and a small of 4～10 years age group. By the renewal investigation, seedling of 1～3 yeas age group has 80.6%, but of 4～10 years age group only has 0.9% that its seed propagation appears a serious breakdown. Around about 60% plants have completed vegetative propagation successfully, and vegetative propagation is a main approach for Longwhip Rhodiola population’s renewal.Longwhip Rhodiola owns definite ability to withstand arctic-alpine, but is imperiled by people’s collecting action. Its life history strategy is that the basis is vegetative propagation for keeping stable quantity of the population farthest, and the chance is seed propagation at infinitesimal quantity for keeping stable climbing quality of the population frailly. It is a vulnerable species. The total resources of caudex are 146.41×104t in Southeastern Tibet.The protection measure is that collecting quantity must be controlled severely, the outlay of bioreactor developing is increased for depressing cost of production, and he outlay of domesticating is increased for that they can grow properly at the low altitude and the commercial caudex contains active ingredient substantially, author offered.更多还原