【作者】 赵义海；

【导师】 符义坤；

【作者基本信息】 甘肃农业大学 ， 草业科学， 2000， 博士

【摘要】 贡嘎山位于青藏高原的东南缘，介于北纬29°20’-30°20’和东经101°30’-102°15’之间，面积约1万km~2，海拔最高达7556米。贡嘎山拥有完整的自然垂直带谱、典型的高山自然景观和呈现出过渡性、混合性、复杂性的自然地理现象；拥有生物区系成分起源古老、分化显著、特有种多、地理成分混杂、替代现象明显的特征；它还拥有发育典型的海洋性冰川。以贡嘎山为依托的有关高山生态方面的研究，对揭示青藏高原及其毗邻地区的形成和演变，对了解横断山地区生态系统的结构与功能及其调控途径，重建功能稳定、结构合理和高生产力的生态系统，保护及合理开发这一地区的自然资源，以及建立山地学和发展地区经济都具有重要的意义。 本文重点研究了贡嘎山亚高山森林生态系统草地亚系统生产力及与生产力形成有关的如演替、植物种多样性及光合作用等因素，地点设在冰川退缩迹地和泥石流迹地，以冰川退缩迹地为主，以泥石流迹地为参考，得出了如下的结论：1 贡嘎山海螺沟冰川从1891到1999年的110年间一直在退缩，其年退缩距离随地势的不同而呈现出忽快急慢的表观特点，但其水平退缩距离（X）和垂直退缩距离（Y）之间存在着显著的相关关系：Y=-0.00024X~2+0.238X+2930.5，R~2=0.9992。结合气象资料的分析，这一时期内冰川呈匀速退缩状态，以其为代表的青藏高原区系气温呈现缓慢和均匀上升的趋势。2 冰川退缩迹地和泥石流迹地上发生着植被的原生演替，冰川退缩迹地上共有草本植物32科61种，泥石流速地上共有草本植物34科59种，在不同演替时间下，迹地草本植物优势种变化剧烈，呈现出明显的格局分布特点。草本植物的物种多样性对群落各个阶段总物种多样性的贡献最大。冰川退缩迹地上演替28年时的草本物种多样性最低；物种多样性最高值出现于退缩110年后。泥石流迹地上中龄林阶段的草本物种多样性最低；成熟林阶段的草本物种多样性最高。3 群落生物量的分布随演替时期的不同也呈现出一定变化。冰川退缩早期生物量绝大部分分布在地下，地上与地下生物量之比最高可达1：9.0。随着演替的进行，这种分布趋势逐渐减缓，地上地下生物量分布接近于1：2。冰川退缩迹地生物量最大值出现于演替58年地段，最小值为演替17年地段。对泥石流迹地地上生物量调查表明，中龄林阶段草本生物量最低，成熟林阶段的生物量最 贡嘎山亚高山森林生态系统草地亚系统生产力及形成机制研究 高，同时发现苔劳生物量所占比重逐渐增大． 4冰门退缩 9年迹地草本群落优势种小叶黄乾MStragalSS polyCladuS）在生长季 早期，光合作用主要受环境温度的影响，光是影响其光合作用能力的主导因子， 生长季末期，其光合作用主要受 pAR的影响．东万草毒（FigQriQ OrientOliS）＋ 鹿蹄草（Pyrola rotundghlia）＋长叶火绒草（Leontopo价urn long＠hurn）群落中， 优势种东方草毒生长初期对PAR变化反应敏感，且在九月前的整个生长期， 其净光合值随PAR的增力。而增加；PAR较低时它的光合效率较高．鹿蹄草M Rtun帅lia）＋大叶菌草（Rubia Ieio。uns）群落中，优势草本鹿蹄草净光合速率 在生长季与 P肌有较强的正相关关系（4月：Y——0．0037X’＋0．752lX－5．3269， R‘一0．8094；6月：Y＝．0刀244X‘＋1．3567X－13．427，R’＝0．6159），其光合生长 初期与PAR相关，生长中后期与温度有关．成熟林群落中，优势草本双舌蟹 甲草（Cacalia davidii）生长初期对光的利用效率较高，生长后期对光的利用能 力有所下降，但仍为正值，其高的生产力是保证该植物分布范围广泛的原因之 一．大叶冷水花（Ptlea mataniiL 南星（Arisaema sppX 离舌囊吾（Ltwlar。 。itchm。）、鹿药（3inilaciM spp）、珠芽艾麻（Laportea bulbgh。）对弱光的吸 收效率较高，但在PAR较大时净光合能力下降．所有草本植物生长早期的净光 合速率为最高，但其小的叶量和叶面积指数（LAI）限制了总的生产力． 5冰川退缩9年迹地的碳循环周期为88年，群落碳周转速度较慢，群落有机物 质处于积蓄阶段，是CO。循环的库；氮元素随演替的进行其合量从接近子零逐 渐上升，磷含量在群落中的变化不明显，二者的积累动态有待于进一步研究． 所有迹地上大量元素中以 C的含量为最高，Na含量为最低．矿质元素尤其是 微量元素中 Ba、Sr、AI、Ti和 Mn的次序基本不变，其它元素次序在不同演替 阶段有不同的变化． 6草本植物种类分布格局、生物量分布格局均与环境因子有关．典范对应分析 （CCA）表明，植物种类分布与PAR、pH值、土壤有机碳、全氮、Co、Zn和 Ni之间有较强的相关关系，其中PAR和Zn的作用最明显，pH和Ni的作用次 之。由于环境因素差异导致的植物分布格局是生物量分布格局的根更多还原

【Abstract】 Gongga Mt, with coverage of 10,000km2 area and alpine mountain 7556 above sea level at peak, is situated in the eastern part of Qinghai-Tibet plateau with the longitude of ~ N and latitude of IOP?0102015 E. It has an intact vertical zone composition, a typical alpine landscape, and a natural geographical character that embodies transitivity, mixity, and complexity together. Its floristic composition originated from primitive time, ftom diverse geographical sources and highly developed, while still possesses some typical species and an evident species substitution. Further on, Gongga Mt. is considered to be invaluable for its typically developed glaciers. Alpine ecology researches concerning Gongga Mt. will undoubtedly uncover long term formation and evolution of Qinghai-Tibetan plateau and its adjacent areas, will certainly unveil structures, functions and its regulating of Hengduan Mt. area so that a steadily functioned, reasonably structured and highly produced ecological system can be formed, and the research will be the key to alpine science formation, district resources protection and utilization, and regional economy. This study focused on productivity and some of its formation mechanism of grassland subsystem of forest ecosystem of subalpine Gongga, such as vegetation succession, biodiversity, and photosynthesis. The Deglaciation Slash and Debris flow Slash were selected as experiment sites, while the former was principally studied and the latter was consulted. The results are as follow: 1. From 1891 to 1999, a 110-year period, Hailuo glacier kept retreating, the yearly retreating distance varied according to site topography. But its retreating rates of vertical (Y) to horizontal (X) significant correlated significantly: Y=- 0.00024X2+0.238X+2930.5, R2=0.9992. Combing with atmosphere data, the glacier 78 was retreating steadily, the temperature of Qinghai-Tibet plateau, represented by Gongga Mt., was getting warmer gradually and steadily. 2. Primitive vegetation successions took place in deglaciation slash and debris flow slash. Botanical composition of the former slash had 31 families including 61 herb species, while the latter had 34 families including 59 herb species. The dominant species varied fiercely at different succession period, thus a distinctive distribution pattern was formed. Compared with tree and shrub, herbs contribute the most to the total species diversity under different community. In glacier retreating area, the 28 year retreated segment has the lowest diversity of herb species, while 110 year retreated segment has the highest. In debis flow slash, the middle-aged canopy segment has the lowest diversity of herb species, while the mature canopy segment has the highest. 3. The biomass pattern varies in accordance with the period of succession. The majority of biomass from the late retreated segment distributed in root, which accounts for 90% (1:9.0 for aboveground: underground). With further succession, this pattern was slowed down, and aboveground to underground ratio reached up to 1:2. In glacier retreating area, the 58-year succeeded segment got the highest biomass, while 17 year succeeded one had the lowest. Survey on biomass to Debis flow slash shows that the middle-aged segment has the lowest while mature canopy segment has the highest, and lichen biomass begins to hold quite percentage in this area. 4. Photosynthesis of Astroga)us polycladus, dorminant species i更多还原