Molecular phylogenetic systematics of twelve species of acipenseriformes based on mtDNA ND4L-ND4 gene sequence analysis

Acipenseriformes is an endangered primitive fish group, which occupies a special place in the history of ideas concerning fish evolution, even in vertebrate evolution. However, the classification and evolution of the fishes have been debated. The mitochondrial DNA (mtDNA) ND4L and partial ND4 genes were first sequenced in twelve species of the order Acipenseriformes, including endemic Chinese species. The following points were drawn from DNA sequences analysis: (i) the two species of Huso can be ascribed to Acipenser; (ii) A. dabryanus is the mostly closely related to A. sinensis, and most likely the landlocked form of A. sinensis; (iii) genus Acipenser in trans-Pacific region might have a common origin; (iv) mtDNA ND4L and ND4 genes are the ideal genetic markers for phylogenetic analysis of the order Acipenseriformes.

Two new species of Actinolaimidae thorne, 1939 (Nemata : Dorylaimida) from China

Two new species of Actinolaimidae are described from China. Trachactinolaimus brevicaudatus n. sp. is 3.4-4.4 mm long; a = 40-60, b = 3.5-5.2, c = 20-21 in female and 34-39 in male; odontostyle length is 29-33 mu m; spicules are 67-77 mu m long; and the stoma has four onchia with numerous mural denticles. The female has a longitudinal vulva, and the male has 20 to 23 contiguous ventromedian supplements. Egtitus sinensis n. sp. is 1.7-2.2 mm long; a = 24-33, b = 3.1-3.9, c = 16-19 in female and 0.7-0.9 in male; odontostyle length is 25-29 mu m; spicules are 55-56 mu m long; and the prerectum 53-77 pm long. The cardia is short and blunt conoid, 13-19 mu m long. The male has 12 to 13 ventromedian supplements at intervals of 2-3 mu m.

Diversity of intestinal helminth communities of carp from six lakes in the flood plain of the Yangtze river, China

The infra- and component communities of intestinal helminths of carp Cyprinus carpio were investigated in six lakes in the flood plain of the lower and middle reaches of the Yangtze River, China. Eight species of helminth parasites were recorded. The intestinal helminth communities were species rich in Niushan and Tonghu lakes where the digenean Asymphylodora japonica was the dominant species, whereas in Qinggang and Yanglan lakes a species-poor helminth community had only one species, Khawia sinensis. The degree of similarity within localities was highest in Qinggang and Yanglan lakes, and was high between communities where K. sinensis was the dominant species. The rich composition of these helminth communities may be because China is the heartland for carp while the poor helminth composition of those in Qinggang and Yanglan lakes may reflect the poor fauna there. It is suggested that species compositions of intestinal helminth communities of carp may be diversified in lakes in the hood plain of the Yangtze River. (C) 1999 The Fisheries Society of the British Isles.

日光温室豇豆产量和品质对水分和氮素水平的响应

依据在日光温室条件下的田间试验,研究了水分和氮素水平对豇豆产量和品质的影响,以期筛选较佳水分和氮素控制指标,为豇豆优质高产提供依据。结果表明:同一氮肥处理下,豇豆产量随土壤水分含量增加而显著增加,达到土壤相对含水量(RH)75%~85%时产量最高,豇豆高产较佳的水分和养分组合为:氮肥120 kg/hm2,壤RH为60%~85%。水分对豇豆鲜菜可溶性糖含量影响不明显;在水分充足条件下氮肥能提高豇豆的可溶性糖含量;水分有助于提高豇豆的Vc含量,水分、氮肥适宜豇豆可获得较高的Vc含量。豇豆硝酸盐含随施氮量增加显著增大。在氮素水平为60~120 kg/hm2条件下,水分对豇豆硝酸盐含量影响不明显,在氮素水平为180kg/hm2条件下,水分明显增加豇豆硝酸盐含量。按照蔬菜中硝酸盐含量安全标准,在氮水平为60~120 kg/hm2条件下豇豆的硝酸盐含量均在250 mg/kg以下,达到一级安全标准。氮水平120 kg/hm2是较佳的豇豆安全施肥量。综合考虑水分和氮肥对豇豆安全品质、营养品质以及产量的效应,建议豇豆生产中氮肥用量为120 kg/hm2左右,田间持水量保持在60%~85%。

鰋鮡鱼类(Glyptosternoid fishes)的系统进化和动物地理学研究

鰋鮡鱼类共包括9 属43 种（亚种），隶属于鲇形目（Siluriformes）鮡科 （Sisoridae）鰋鮡亚科（Glyptosternae）中鰋鮡族（Tribe Glyptosternini）的鰋鮡 亚族（Subtribe Glyptosternina）。鰋鮡鱼类形态上的共同特征为：无胸吸着器，胸、 腹鳍水平展开，第一根鳍条完全分节或在外缘生出许多软骨细条，被外表皮所裹， 在腹面看到的是许多与分节或软骨细条大致对应的横纹皱褶。鰋鮡鱼类集中分布 于青藏高原周边的水系中，部分属种向西分布到了中亚地区的阿姆河上游，是适 应山区急流环境的一群鱼类。近年来一系列的研究表明，鰋鮡鱼类为一单系类群， 它的起源和演化与青藏高原的隆升有着直接的关系。鰋鮡鱼类的系统发育研究， 可以为青藏高原隆升的年代、幅度和形式提供间接的证据，其系统发育树的拓扑 结构也直接反映了东喜马拉雅地区诸水系的形成与演变。 本研究对鰋鮡鱼类9 属进行了系统整理。1. 发现并描述了异齿鰋属 （Oreoglanis）两新种，分别为分布于景东无量山（澜沧江水系）的景东异齿鰋 （O. jingdongensis）和分布于怒江水系南景河和南滚河的无斑异齿鰋（O. immaculatus）。认为分布于中国的异齿鰋属鱼类均属于尖须异齿鰋种组（O. siamensis species group）。指出区分异齿鰋属两个种组：尖须异齿鰋种组和细尾 异齿鰋种组（O. delacouri species group）的特征是下唇中部是否具有中央缺刻， 尾型的差别（新月型尾或凹型尾）不能用来区分两个种组，给出了异齿鰋属的检 索表，并绘制了异齿鰋属鱼类分布图。2. 对鮡属（Pareuchiloglanis）鱼类进行了 系统整理，通过外部形态度量性状的比较，认为分布于澜沧江水系的，曾经被鉴 定为扁头鮡（P. kamengensis）的标本，应属于大鳍鮡（P. macropterus），扁头鮡 和大鳍鮡之间的最明显的差别在于腹鳍前长的不同。前者的腹鳍前长为体长的 53.2-64.9%，后者的腹鳍前长均不达体长的50%。3. 通过比较金沙江水系分布的 5 种鮡属鱼类，中华鮡（P. sinensis）、前臀鮡（P. anteanalis）、壮体鮡（P. robusta）、 四川鮡（P. sichuanensis）和天全鮡（P. tianquanensis），认为天全鮡和四川鮡之 间分布水系重叠，外部形态亦无差别，天全鮡很可能为四川鮡的同物异名。给出 了鮡属鱼类的系统检索表，并绘制了鮡属鱼类分布图。利用分子系统学的原理和方法对鰋鮡鱼类进行系统发育研究。测定了6 属 15 种鰋鮡鱼类和鮡科中非鰋鮡鱼类4 属7 种共28 个体的线粒体Cyt b 基因部分 片段和全序列（1138 bp），结合从GenBank 下载的相关类群相同的基因序列，以 魾属（Bagarius）的巨魾（B. yarrelli），纹胸鮡属（Glyptothorax）的穴形纹胸鮡 （G. cavia）、亮背纹胸鮡（G. dorsalis）、扎那纹胸鮡（G. zainaensis），福建纹胸 鮡（G. fukiensis fukiensis）、海南纹胸鮡（G. fukiensis hainanensis），黑鮡属（Gagata） 的长丝黑鮡（G. dolichonema）以及褶鮡属（Pseudecheneis）的黄斑褶鮡（P. sulcatus） 和无斑褶鮡（P. immaculatus）作为外类群，采用贝叶斯法（Bayesian）、最简约 法（maximum pasimony, MP）和邻接法（neighbour-joining, NJ）构建系统发育树。 结果显示： 1. 鰋鮡鱼类为一单系类群，并且与褶鮡属互为姐妹群关系； 2. 原鮡属、鰋属和凿齿鮡属是鰋鮡鱼类的三个基部类群； 3. 异齿鰋属构成为一个单系群，大鳍异齿鰋最早从该属的基部分化出来； 4. 石爬鮡属构成一个单系，并与分布于金沙江水系的中华鮡＋前臀鮡构成姐妹 群，黄石爬鮡和青石爬鮡的单倍型相互交错；显示两个物种的分类是不合适的， 而是同一水系不同支流种群之间梯度变异的例子，依据本次研究所得出的三个分 支图，结合青石爬鮡自西至东分布于金沙江、雅砻江、大渡河、青衣江、岷江等 的分布格局以及形态特征的分布，显示形态特征的分布变化有以下趋势：自西至 东，腹鳍位置逐渐前移；颌须渐趋缩短；胸鳍趋向发达、伸达腹鳍起点。这些变 化趋势是同一水系不同支流种群之间梯度变异的极好例子； 5. 分布于澜沧江以西（包括澜沧江）水系的鮡属鱼类（扁头鮡、细尾鮡、短鳍 鮡）与分布于怒江和伊洛瓦底江水系的拟鰋属鱼类构成为一支，并且二者共同与 分布于元江上游（红河水系）的大孔鮡构成为单系。其中，短体拟鰋和拟鰋互为 姐妹种；而扁头鮡和短鳍鮡也互为姐妹种；细尾鮡的系统地位则尚不能确定； 6. 无论在MP 树、贝叶斯树还是NJ 树中，石爬鮡属、鮡属、拟鰋属和异齿鰋属 构成一个单系，并且支持率达到了100％。 7. 鰋属位于鰋鮡鱼类的基部，是较早就从鰋鮡鱼类祖先中演化出来的一个类群， 鰋类的口吸盘是一个趋同性状，是在急流环境条件下形成的一种适应性性状，在 鰋类各属中不是同源特征； 8. 鮡属鱼类不是一个单系类群，分布于金沙江流域的鮡属鱼类与同流域分布的石爬鮡属鱼类聚成一支；澜沧江及其以西水系分布的鮡属鱼类与同流域分布的拟 鰋属鱼类聚成一支，之后这两支又同异齿鰋属共同构成为一个大支。 结合鰋鮡鱼类的系统发育分支图对其动物地理学进行研究。鰋鮡鱼类是由类 似纹胸鮡属（Glyptothorax）鱼类的祖先演化而来，鰋属（Exostoma）和凿齿鮡 属（Glaridoglanis）是较早就从从类似原鮡的祖先中演化出来，鮡属、石爬鮡属、 拟鰋属和异齿鰋属这一大支由类似原鮡的祖先演化而来。在青藏高原强烈隆起等 重大地理隔离事件发生之前，类似于现生的原鮡属鱼类已经广布喜马拉雅山脉东 西两侧。在青藏高原强烈隆起等重大地理隔离事件发生后，鰋鮡鱼类在相同的地 理隔离下独自演化为现在的分布格局。

中国长吻松鼠属（Dremomys）的分类研究

本文从外部形态，骨骼特征，阴茎骨特征，背毛髓质和角质鳞片的比较以及地理分布等方面入手，对分布于我国的长吻松鼠属(Dremomys)松鼠的分类进行了系统整理，认为红腿长吻松鼠Dremomys pyrrhomerus，橙喉长吻松鼠Dremomys gularis应是有效的种。同时记述了该属的两个新亚种D.lokriah quboensis.subsp.nov. （西藏曲波河谷）； D.pernyi chaundongensis.subsp.nov.（四川东北部，湖北西北部，陕西南部）。

中国蜜环菌属系统学研究

对中国已经发表的13个异宗配合的蜜环菌生物种的200多号标本用形态学和解剖学的方法进行了系统学研究，对其进行了详细的形态结构描述和重要性状的显微结构绘图，讨论了它们和近缘种间的区别，总结了这些种类的世界分布，国内分布范围和生境，给出了中国蜜环菌属的分种检索表，在此基础上报道新种5个：中国蜜环菌（CBS F）A. sinensis H.C. Wang，G.F. Qin & J. Zhao，褐囊蜜环菌（CBS H）A. bruneocystidia H.C. Wang，G.F. Qin & J. Zhao，秦氏蜜环菌（CBS J）A. qinii H.C. Wang & J. Zhao，杏孢蜜环菌（CBS L）A. amygdaliformospora H.C. Wang，G.F. Qin & J. Zhao，紫盖蜜环菌（CBS N）A. violacea H.C. Wang，G.F. Qin & J. Zhao。 用性亲和性实验对我国的同宗配合蜜环菌进行了研究，改进了用于同宗配合蜜环菌性亲和性实验的实验方法，将我国的同宗配合蜜环菌划分为8个新生物种，澄清了过去对它们的模糊认识，同时探讨了它们和欧洲及北美异宗配合的蜜环菌A. mellea的关系。 选取世界各地同宗配合的蜜环菌和我国部分存在疑问的异宗配合的蜜环菌生物种菌株进行了部分β-Tubulin序列测定，在此基础上进行了系统发育分析，探讨了各生物种间的系统发育关系，对一些疑难问题进行了讨论。

中国辽宁海洋放线菌资源、生物学特性及一株新种的鉴定命名

本论文在国内外首次报导了中国辽宁海洋放线菌资源考察研究结果。结果表明中国辽宁海洋放线菌资源丰富；在分离出的海洋放线菌中以链霉菌属居绝对优势，占所分离菌株总数的90%以上，此外尚有少量的海洋小单孢菌和海洋诺卡氏菌；所获提的海洋链霉菌可分为7个类群，已鉴定出11个种和1个新种。选择生长较快的链霉菌属13株菌株，对其形态特征、培养特征、生理生化特征、抗菌谱、细胞化学组分、DNA中的G+C mol%等内容进行系统研究。结果，全部13株菌株均能忍耐6%NaCl和pH13的碱性，5株菌株能耐受10%NaCl；G+C mol%均在69.5%-72.5%之间；均为细胞壁I型；但在形态特征、培养特征、生理生长特性、抗菌谱等方面各菌株之间又有差异。根据链霉菌鉴定手册，将13株菌株中的12株逐一定名：（1）将菌株H72-9定名为威德摩尔链德菌（S. wedmorensis, H72-9），（2）将菌株H73定名为细黄链霉菌（S. microflavus, H73）（3）将菌株H74-2定名为天蓝色链霉菌生天蓝亚种（S. coelicolor，subsp. coelicoferus, H74-2），（4）将菌株Hai-75定名为娄彻氏链霉菌（S. rochei, Hai-75），（5）将菌株H75-2定名为鲜黄链霉菌（S. galbus, H75-2），（6）将菌株H76定名为束丛链霉菌（S. fasciculus, H76），（7）将菌株H77定名为灰红链霉菌（S. griseoruber, H77），（8）将菌株H78-1定名为栗褐链霉菌（S. badius, H78-1），（9）将菌株J5定名为吡啶霉素链霉菌（S. pyridomyceticus, J5），（10）将菌株J7定名为锈亦链霉菌（S. rubiginosus, J7），（11）将菌株J10和J11定名为栗色浑圆链霉菌（S. castaneoglobosus）。将13株中的另一株海洋放线菌Hai-74确定为放线菌新种，它除了在形态特征、培养特征、生理生化特性等与已知近似种有明显的不同外，最主要的是在其独特的“索状”孢子丝结构，为国内外首次发现，故将此新种命名为索孢天蓝链霉菌（Strepomyces multisticho-cateniformis n. sp. Xie and Ding）。在研究中国辽宁海洋放线菌的抗菌性能中，我们还首次发现并报道了海洋细黄链霉菌H73的抗菌物质，它能显著减轻大豆连作障碍（重茬大豆根际土壤紫青霉菌及其毒素对大豆的危害），因此在今后它很有可能被用来研制一种能够减轻大豆连作障碍的新型农用抗生系。为此，我们对海洋细黄链霉菌H73的基因组DNA文库进行了构建，这将为今后研究有关抗菌基因方面的工作奠定基础。

极端环境放线菌的分离及多相分类研究

本文综述了放线菌分类学研究的目的和作用，分析了放线菌分类学的历史和现状，介绍了当前放线菌多相分类研究中所采用的技术方法及适用范围。同时还重点介绍了极端高温、低温、高盐放线菌分离及分类研究的进展。从云南采集高温温泉水样、火山口土样，从云南、新疆等地采集雪山土样，从新疆、青海等地采集盐碱土样进行放线菌分离，对不同极端环境下的放线菌分离方法进行探讨，并对分离到的部分典型放线菌菌株采用形态特征、培养特征，生理生化测定，细胞化学组份分析，DNA G+C mol%和DNA同源性测定，以及16SrDNA全序列分析等相结合的多相分类技术进行系统的分类研究。从表型、基因型及系统发育三个不同层次对其分类地位进行了最终确定。其中，分离自云南洱源温泉的菌株YIM60013和腾冲火山口的菌株YIM60032分别确定为高温放线菌属的两个新种：白色高温放线菌（Thermoactznomyces albus sp. nov.）和云南高温放线菌（Termoactomyces yunnanensis sp. nov.）；分离自新疆北疆地区的一株低温放线菌菌株，结合其形态特征、细胞化学组份及16S rDNA序列分析将其鉴定为链霉菌的一个新种，北疆链霉菌（Streptomyces beijiangensis sp. nov.）；来自新疆盐碱土样的6株嗜盐放线菌菌株YIM90001-90006中，菌株YIM90001被命名为嗜盐普氏菌新种(Prauserella halophila sp. nov.），菌株YIM90005被 命名为脱卤普氏菌新种（Prauserella dehalogenans sp. nov.），菌株YIM90002和YIM90003鉴定为拟诺卡氏菌科中的链单抱菌新属Streptomonospora gen. nov.）和它的两个新种：菌株YIM90002定为盐生链单抱菌新种(Streptomonospora saline sp. nov.），菌株YIM90003定为白色链单抱菌新种(Streptomonospora alba sp. nov.）；菌株YIM90004和YIM90006分别被确定为拟诺卡氏菌属的一个新种和一个亚种：新疆拟诺卡氏菌新种（Nocardopsi sxiniangensis sp. nov.）和嗜阿拉伯糖新疆拟诺卡氏菌亚种( Noocardiopsi sxiniangensis subsp���arabicus subsp���nov，）。

中国管口苔属（Solenostoma Mitt.）植物研究

本文是对中国管口苔属（Solenostoma Mitt.）植物种类的初步整理和研究。共记载3亚属、44种及1变种，其中有24个新组合，如下：Solenostoma (L.) subulatum (Evans) Wang, S. (L.) atrovirens (Schleich) Wang, S. (L.) grossitextum (Steph.) Wang, S. (S.) fusiformis (Steph.) Wang, S. (S.) lanigerum (Mitt.) Wang, S. (S.) pseudocyclops (Inoue) Wang, S. (S.) subrubrum (Steph.) Wang, S. (S.) pyriflorum var.minutissimum (Amak.) Wang, S. (S.) sinensis (Nich.) Wang, S. (S.) faurianum (Beauvd) Wang, S. (S.) cyclops (HAtt.) Wang, S. (S.) apressifolium (Mitt.) Wang, S. (S.) schaulianum (Steph.) Wang, S. (P.) Japonicum (Amak.) Wang, S. (P.) tetragonum (Lindb.) Wang, S. (P.) rosulans (Steph.) Wang, S. (P.) thermarum (Steph.) Wang, S. (P.) hattorianum (Amak.) Wang, S. (P.) rupicolum (Amak.) Wang, S. (P.) rubripunctatum (Hatt.) Wang, S. (P.) hasskarlianum (Nees) Wang, S. (P.) setulosum (Herzog) Wang, S. (P.) truncatum (Nees) Wang, S. (P.) tsukushiensis (Amak.) Wang, 其中有14种及1变种为中国分布新纪录，如下：Solenostoma (L.) grossitextum (Steph.) Wang, S. (S.) fusiformis (Steph.) Wang, S. (S.) faurianum (Beauvd.) Wang, S. (S.) cyclops (Hatt.) Wang, S. (S.) pusillum (Jens) Steph., S. (S.) pyriflorum var. minutissimum (Amak.) Wang, S. (P.) rubripunctatum (Hatt.) Wang, S. (P.) thermarum (Steph.) Wang, S. (P.) rosulans (Steph.) Wang, S. (P.) hyalinum (Lyell) Mitt., S. (P.) radicellosum Mitt, S. (P.) Japonicum (Amak.) Wang, S. (P.) tsukushiensis (Amak.) Wang, S. (P.) hatterianum (Amak.) Wang, S. (P.) rupicolum (Amak.) Wang, 其中还有6种中国特有种，如下：Solenostoma (L.) subulatum (Evans) Wang, S. (P.) flagellalioides Gao, S. (P.) microphyllum Gao, S. (P.) orbicularifolium Gao, S. (P.) setulosum (Herzog) Wang, S. (S.) sinensis (Nich.) Wang。本文还对管口苔属（Solenostoma Mitt.）的研究历史作了回顾。对中国管口苔属各分类群的鉴别特征、产地和地理分布作了叙述，对区系成份做了分析。并对前人工作中的某些问题进行了讨论，提出了自己的看法。

CO2浓度和温度升高对红桦可溶性蛋白含量和分配的影响

随着工业化的发展，大气中二氧化碳的浓度(CO2)预测从现在的平均350μmol·mol-1升高到2030年的570μmol·mol-1，其增温作用将持续多个世纪。植被在大气二氧化碳减排以及调控区域水热状况过程中起重要作用，而其机理过程目前十分不清楚。本实验应用自控、封闭、独立生长室，研究了CO2浓度和温度升高对红桦根、茎、叶和枝可溶性蛋白含量和分配的影响，从蛋白水平上来解释川西亚地区的建群种-红桦对CO2升高和温度升高及其交互作用的响应规律，为全球气候变暖川西亚高山的植被保护和恢复提供理论依据。研究结果表明： 1. CO2浓度升高增加了可溶性蛋白的总量，改变了可溶性蛋白分配模式，即，可溶性蛋白分配到根的比例增加，分配到茎、枝、叶的比例减少。可能意味：在CO2浓度升高条件下，红桦根系的生长和营养物质吸收功能将会增强。 2. CO2浓度升高增加了根和茎的清蛋白含量，降低了叶片的清蛋白含量，叶片的球蛋白含量、醇溶蛋白含量和谷蛋白含量均增加。表明CO2浓度升高增加了清蛋白在根中积累，球蛋白、醇溶蛋白和谷蛋白大量在叶片中积累；前人研究所指出的CO2浓度升高使植物叶片可溶性蛋白的含量降低可能仅仅是由于清蛋白含量的降低造成的。 3. 温度升高使红桦幼苗整株所含可溶性蛋白总量增加，但可溶性蛋白总量的分配因红桦幼苗器官的不同而异。温度升高下根、茎、叶和枝的分配量分别占总可溶性蛋白的27.74%、35.57%、23.00%、13.68%，即茎＞根＞叶＞枝。对照的根茎叶枝的分配量分别占总可溶性蛋白的21.01%、41.41%、23.08%、14.50%，即茎＞叶＞根＞枝。表明温度升高使可溶性蛋白分配到根的比例增加，有利于根的可溶性蛋白的积累，增强了根吸收水分和矿质营养的能力，从而有利于根系的生长。 4. 温度升高处理下清蛋白和球蛋白在根中含量升高，在茎、叶和枝中含量下降，但没有达到显著水平；醇溶蛋白在根和叶中含量显著增加；谷蛋白在茎中的含量显著降低。表明温度升高增加清蛋白和球蛋白在红桦幼苗根部的积累，也有利于根和叶醇溶蛋白的积累，但不利于谷蛋白在茎的积累；温度升高条件下叶片可溶性蛋白升高是醇溶蛋白在叶片中积累的结果。 5. CO2浓度和温度同时升高条件下红桦幼苗的可溶性蛋白总量增加很少，只有分配到茎的可溶性蛋白比例增加，并且对可溶性蛋白分配规律没有影响。CO2和温度同时升高下红桦幼苗枝的可溶性蛋白含量的降低是可溶性蛋白总量的降低而不是碳水化合物稀释的结果，并且CO2和温度同时升高对红桦幼苗的生长没有明显的促进作用。 6. CO2和温度同时升高处理对可溶性蛋白含量有显著影响。清蛋白含量在根、茎、叶和枝中均降低，球蛋白含量在根中显著降低，醇溶蛋白含量在根、茎、叶和枝中均降低，谷蛋白含量在根中显著降低。表明CO2浓度和温度同时升高对根的影响显著，即降低了根的可溶性蛋白含量，可能导致根的吸收能力下降。 7. 因此，CO2和温度同时升高对可溶性蛋白影响不能简单地通过CO2和温度单因子影响机理来解释。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. Atmospheric CO2 concentration are predicted to increase from 350μmol·mol-1 now to 570μmol·mol-1 2030. And temperature will continue to increase for several centuries as a result of CO2 enrichment. Vegetation play a key role in reducing atmospheric CO2 and adapting and controlling warter and energy process in a certain region, while the underlying mechanism are not clear, yet. Betula albo-sinensis, as the dominating tree species of subalpine dark coniferous forest in west Sichuan province, play an important role in determing structure and function of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (ambient±350±25μmol·mol-1), increased temperature (ambient±2.0±0.5℃) and their combination on contents and allocation of soluble protein were studied in independent and enclosed-top chamber system under high-frigid conditions. Chambers with ambient CO2 concentration and temperature are taken as control. The results are as the following, 1) Elevated atmospheric CO2 increased the accumulation of total weight of soluble protein in whole plant and changed allocation of soluble protein in red birch by increasing its allocation to roots and reducing its allocation to stem. This caused much more accumulation of soluble protein in roots which might help to prompt growth, development and nutrient absorption ability of roots. 2) Treatment EC increased content of albumin in roots and stems, reduced the content of albumin in leaves, and increased the content of globulin, promalin and glutenin in leaves. That is to say EC increased the accumulation of albumin in roots and accumulation of globulin, promalin and glutenin in leaves. The reduced soluble protein contents in plant leaves by EC, as reported by former researchers, are mainly resulted from the reduced content of albumin in leaves. 3) Elevated temperature increased the total of soluble proteins, but its allocation was dependent on organs. In treatment ET, roots, stems, leaves and branches take 27.74%, 35.57%, 23.00% and 13.68% of total weight of soluble protein. In treatment CK, roots, stems, leaves and branches take 21.01%, 41.41%, 23.08% and 14.50%. Elevated temperature changed allocation of soluble proteins in that it stimulated soluble proteins accumulation in roots and improved the uptake of water in roots. 4) Treatment ET increased the content of albumin and globulin in roots, and reduced the content of albumin and globulin in stems, leaves and branches. The content of promalin in roots and leaves was increased significantly, and the content of glutenin in stems was reduced significant. This suggested that ET stimulated the accumulation of albumin and globulin in roots and accumulation of promalin in leaves and roots; that treatment ET increased content of soluble protein in leaves was mainly resulted from the increased promalin content in leaves. 5) Regarding treatment ETC, the total of weight of soluble proteins increased, but not significantly; but increased in stems. So the combination of elevated atmospheric CO2 and temperature had not changed the allocation of soluble proteins in red birch seedling and reduced soluble proteins in branches were not the result of increased carbohydrate. 6) Treatment ETC reduced the content of albumin and promalin in roots, stems, leaves and branches, reduced the content of globulin and glutenin in roots significantly. That is to say elevated atmospheric CO2 and temperature reduced the content of soluble proteins in roots significantly which might help to prompt growth, development and nutrient absorption ability of roots. 7) The effects of elevated atmospheric CO2 and temperature on soluble protein cannot be simply interpreted through their mechanism that obtained when they were imposed on plant separately.

土壤微生物和酶对大气CO2浓度与温度升高的响应

土壤微生物(Soil microbes)是生态系统的重要组成部分，它参与土壤中复杂有机物质的分解和再合成，也参与C、N、S、P等的循环。土壤酶(Soil enzyme)是土壤中具有生物活性的蛋白质，它与微生物一起推动着土壤的生物化学过程，并在树木营养物质的转化中起着重要的作用。鉴于土壤微生物和土壤酶对环境变化的敏感性，它们在CO2浓度和温度升高时的反应将在很大程度上影响森林生态系统的结构和功能。因此，要全面评价大气CO2浓度和温度升高对整个生态系统的影响，有必要对CO2浓度和温度升高条件下的土壤微生物的反应进行深入的研究与探讨。本文应用自控、封闭、独立的生长室系统，研究了川西亚高山岷江冷杉（Abies faxoniana）根际、非根际土壤微生物数量，红桦（Betula albosinensis）根际微生物数量以及根际、非根际土壤酶活性对大气CO2浓度(环境CO2浓度+350±25μmol·mol-1，EC)和温度(环境温度+2.0±0.5℃，ET)升高及两者同时升高(ECT)的响应。结果表明： 1) EC和ET显著增加岷江冷杉根际微生物数量，但不同微生物种类对EC和ET的反应有所差异。6、8和10月，岷江冷杉根际微生物数量与对照(CK)相比，EC处理的根际细菌数量分别增加了35%、164%和312%，ET处理增加了30%、115%和209%；EC和ET处理对根际放线菌和根际真菌数量影响不显著。ECT处理的根际放线菌数量分别增加了49%、50%和96%，根际真菌数量增加了151%、57%和48%；而ECT对根际细菌数量影响不显著。EC、ET和ECT处理对岷江冷杉土壤微生物总数的根际效应明显，其R/S值分别为1.93、1.37和1.46(CK的R/S值为0.81)。 2) 红桦根际微生物数量对EC、ET和ECT的响应不同。生长季节(5~10月)，高密度的红桦根际细菌数量与CK 相比，EC的根际细菌数量分别增加28%、33%、423%、65%、43%和79%，而低密度的红桦根际细菌数量增加不显著。ET能显著增加根际细菌数量(7~10月)，其中高密度的根际细菌数量分别增加了377%、107%、35%、22%，而低密度的根际细菌数量分别增加了27%、27%、64%、48%；ECT对两个密度水平下根际细菌数量均未产生有显著的影响。高、低密度的红桦根际放线菌和根际真菌数量与 CK 相比，EC显著增加了低密度的红桦根际放线菌数量，而对高密度的根际放线菌数量无显著影响；ET和ECT对高低密度的红桦根际放线菌数量均未产生显著影响。EC和ET对高低密度的根际真菌数量也无显著影响，而ECT却显著增加了高低密度的根际真菌数量。 3) EC、ET和ECT处理的低密度红桦根际微生物(细菌、放线菌和真菌)数量没有显著高于或低于高密度根际微生物数量，表明短期内密度对红桦根际微生物数量不产生影响。 4) 不同种类的氧化还原酶对EC、ET和ECT的响应不同。5~10月，EC的红桦根际过氧化氢酶活性是CK 的1.44、1.06、1.11、1.10、1.12和1.24倍，差异显著(6月除外)；ET和ECT处理根际过氧化氢酶活性无显著增加。EC的红桦根际多酚氧化酶活性比CK显著增加；ET的根际多酚氧化酶活性显著高于CK(8月除外)。ECT的根际多酚氧化酶活性高于CK，差异不显著。EC的根际脱氢酶活性分别增加了46%、40%、133%、48%、17%和26%，差异显著。5~7月，ET和ECT的根际脱氢酶活性高于CK的脱氢酶活性，而8~9月则相反，差异性均不显著。 5) EC、ET和ECT对不同种类的水解酶的影响不同。EC能显著增加红桦根际脲酶活性，5~10月分别增加了29%、42%，、70%、67%、59%和57%。ET和ECT 对根际脲酶活性未产生显著影响。EC显著提高根际转化酶活性，5、6和9月EC的根际转化酶活性分别比CK高51%、42%和40%。5和10月，ET的根际转化酶活性低于CK，而其余月份却高于CK，但均具有显著性差异。ECT的根际转化酶活性与CK的根际转化酶活性有显著性差异(9月除外)，5、6和7月的根际转化酶活性分别提高了94%、198%和67%。 6) 与CK相比，EC、ET和ECT的非根际土壤微生物数量以及非根际土壤酶活性均无显著提高。EC、ET和ECT的过氧化氢酶、脲酶的根际效应明显，而多酚氧化酶和脱氢酶根际效应不明显。EC和ECT的转化酶根际效应明显，而ET的转化酶根际效应不明显。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. In past decades, considerable efforts had been put into investigating the effects of climate change on processes of forest ecological system. In general, studies had been mainly focused on the effects of elevated atmospheric CO2 on plant physiology and development, litter quality, and soil microorganisms. Studies showed that there was variation in the responses of root development and below-ground processes to climate between different plant communities. Since the concentration of CO2 in soil was much higher (10~50 times) than in the atmosphere, increasing levels of atmospheric CO2 may not directly in fluence below ground processes. Betula albosinensis and Abies faxoniana, as the dominated tree species of subalpine dark coniferous forest in the western Sichuan province, which play an important role in the structure and function of this kind of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (350±25μmol·mol-1), increased temperature (2.0±0.5℃) and both of the two on the number of rhizospheric microbe and rhizospheric enzyme activity were studied by the independent and enclosed-top chamber’ system under high-frigid conditions. Responses of rhizospheric bacteria, actinomycetes and fungi number of Betula albosinensis and Abies faxoniana under different densities(high density with 84 stems·m-2, low density with 28 stems·m-2 ), and rhizospheric enzyme activity of Betula albo-sinensis to elevated CO2 concentration and increased temperature were analyzed and discussed. The results are as the following, 1) In comparion with the control, the numbers of rhizospheric bacteria of Abies faxoniana were increased by 35%, 164% and 312% significantly in June, August and October respectively of EC, and were increased by 30%, 115% and 209% respectively of ET.However the effect of EC and ET on rhizospheric actinomycetes and fungi was not significant. The number of rhizospheric actinomycetes of ECT were increased significantly by 49%, 50% and 96% respectively, and the increment of rhizospheric fungi were 151%, 57% and 48% respectively .The effect of ECT on rhizospheric bacteria was not significant. Rhizospheric effect of soil microbe for all treatments was significant, with the R/S of 1.93, 1.27 and 1.46 for EC, ET and ECT, respectively. 2) Treatment EC improved the number of rhizospheric bacteria of Betula albosinensis under high density significantly in comparison with the control, over the growing season, the greatest increment of rhizospheric bacteria was from July. However, EC had no effect on the number of rhizospheric bacteria under low density. Except May and June, treatment ET improved the number of rhizospheric signifcantly. The effect of treatment ECT on the number of rhizospheric bacteria under different densities was not significant. Of treatment EC, the number of rhizospheric actinomycetes of Betula albosinensis under low density were increased significantly, however, treatment EC did not stimulate the number of rhizospheric actinomycetes under high density. Simultaneously, treatment ET and ECT did not stimulate the number of rhizospheric actinomycetes. Finally, in treatment ECT, the number of rhizospheric fungi under high density were increased significantly, however treatment EC and ET did not stimulate the number of rhizospheric fungi under different densities. 3) Of treatment EC, ET and ECT, the number of rhizospheric microbe of Betula albosinensis under low density were not more or fewer than that of microbe under hign density along the growing season, which showed that plant density had no effect on the nmber of microbe. 4) From May to October, 2004，rhizospheric catalase activity of Betula albosinensis of treatment EC was 1.44, 1.06, 1.11, 1.10, 1.12 and 1.24 times as treatment CK respectively, and the difference was statistically significant(except June). Treatment ET and ECT did not increase rhizospheric catalase activity significantly. In treatment EC, the rhizospheric pohyphenol oxidase activity was higher than treatment CK significantly. The rhizospheric pohyphenol oxidase activity of treatment ET was higher than CK significantly (except August). The rhizospheric pohyphenol oxidase activity of treatment ECT was higher than CK, but the difference was not statistically significant. Over the growing period, the rhizospheric dehydrogenase activity were increased 46%, 40%, 133%, 48%, 17% and 26% respectively by treatment EC, and the difference was statistically significant. From May to July, the rhizospheric dehydrogenase activity in treatment ET and ECT was higher than CK, but from August to October, the rhizospheric dehydrogenase activity was lower than CK, the difference was not significant. 5) Treatment EC increased rhizospheric urease activity significantly, from May to October, rhizospheric urease activity were increased 29%, 42%, 70%, 67%, 59% and 57% respectively by EC. Treatment ET and ECT had no effect on rhizospheric urease activity. Treatment EC improved rhizospheric invertase activity significantly, in May, June and September, the rhizospheric invertase activity of treatment EC were increased 51%, 42% and 40% in comparison with the control. Except May and October, the rhizospheric invertase activity of treatment ET was markly higher than CK. The rhizospheric invertase activity of treatment ECT was significantly different from CK (except September), in May, June and July treatment ECT increased rhizospheric invertase activity by 94%, 198% and 67% respectively. 6) In comparison with the control, treatment EC, ET, and ECT had no effect on the number of non-rhizospheric microbe and non-rhizospheric enzyme activity. Rhizospheric effect of catalase and urease for all treatments was significant, but rhizospheric effect of pohyphenol oxidase and dehydrogenase was not significant. Rhizospheric effect of invertase of EC and ECT was significant, but rhizospheric effect of invertase of ET was not significant.

岷江冷杉林群落几种树苗对光强的响应与适应

在青藏高原东部的亚高山针叶林区，如何尽快恢复这一生态脆弱地区的植被，改变生态环境恶化的趋势，是一个十分重要的课题。光一直被认为是植物种间相互替代，尤其是森林演替过程中植物相互替代或植被恢复中的关键环境要素之一。植物能否适应林冠下或林窗中异质的、或多变的光照条件，对其在林中的生存、分布、更新以及森林动态都是非常重要的。 本文以青藏高原东部亚高山针叶林的主要森林类型——岷江冷杉林群落的几种树苗为研究对象，采用实验生态学、生理及生物化学等方法，通过模拟针叶林不同大小林窗内光照强度的变化，在中国科学院茂县生态站内采用遮荫处理设置6个光照梯度（100、55、40、25、15与7%全光照），来研究具有不同喜光特性的植物对光强的响应与适应机制，其研究结果可为揭示亚高山针叶林的演替规律、以及人工林下幼苗的存活与定居提供科学依据，也能为苗木的生产与管理提供科学指导，尤其是对针阔树种在不同光强下的响应与适应的比较研究，能为如何将阔叶树种整合到人工针叶林中提供新的思路。 光强对植物生长的影响 光强对植物的生长具有重要作用，不同植物在各自适宜的光强梯度下才能生长良好。通过一个野外盆栽实验，来研究不同光强对植物生长的影响（第三章）。主要研究结果如下，低光强下植物株高/茎生物量增加，说明植物会将生物量更多用于高生长，以便有效地拦截光资源；在强光下，植物将生物量更多地向根部分配，使得植物在强光下能够吸收更多的水分，而避免干旱胁迫。 在第一个生长季节，以相对生长速率（RGR）表示，红桦和青榨槭在100%全光照下RGR最大，粗枝云杉在55%最大，岷江冷杉在25-40%下较好；然而，在第二个生长季节，2种阔叶树的相对生长速率（RGR）的适宜光强则变为25-55%，云杉为55-100%，而冷杉为25-100%。可见，从第一年到第二年，2种阔叶树苗更适宜在部分荫蔽的条件下生长；而2种针叶树苗对光的需求则逐渐增加，这可能是增加对根生物量相对投资的结果，因为以这种方式，强光下生长的针叶树幼苗更能保持其内部水分平衡，其生长不会因干旱胁迫而受到严重影响。另外，严重遮荫会引起冷杉幼苗死亡。 植物对光强的生理适应 植物可以通过自身形态和生理特征的调整，来发展不同的光能利用策略从而能够在林中共存。通过一个野外盆栽实验，研究了不同光强下生长的几种树苗的生理特征（第四章）对不同光强的响应与适应。结果显示：强光下，粗枝云杉和红桦的光合能力增加，而岷江冷杉和青榨槭在中度遮荫（25-55%）的条件下光合能力最大。植物叶氮和叶绿素含量增高，而光补偿点和暗呼吸速率降低，这些都是植物对低光环境的适应性反应；而强光下植物叶片和栅栏组织变厚，是对强光的一种保护性反应。 植物对光的可塑性反应 不同植物会表现出对光适应有利的生理和形态可塑性反应。本文对第三章、第四章的实验数据进行可塑性指数分析，来研究植物对光强的表型可塑性反应（第五章）。结果显示，生理特征调整是植物对不同光环境的主要适应途径。红桦和青榨槭的可塑性指数平均值要大于粗枝云杉和岷江冷杉，充分表明这2种阔叶树在生理和形态上较强的可塑性更有利于对光环境的适应，而具有比耐荫树种更强的适应能力。另外，2种针叶树相比，云杉的适应性更强。本研究结果支持树种的生理生态特性决定了其演替状况和生境选择的假说。 植物的光抑制与防御 当植物叶片吸收了过多光能，会发生光抑制现象。植物对光抑制的敏感性及防御能力对其生长具有重要意义。本文通过两个野外盆栽实验，研究了生长在强光下（第六章）和变化光强下（第八章）植物的光抑制现象及其防御策略。结果表明，在强光下或从遮荫状态转入强光下，植物都会发生光抑制，其对光抑制的敏感性与植物的耐荫性（或喜光）和演替状态有密切联系。长期生长在强光下的植物受到光抑制是可恢复的，而当处于荫蔽环境的植物突然暴露于强光下时，受到的光抑制不能完全恢复，可能是（部分）光合机构受到破坏的缘故。粗枝云杉和青榨槭防御光抑制伤害的能力较强，热耗散是其防御光抑制的主要途径。长期的强光作用能使岷江冷杉和红桦发生严重光抑制，甚至光伤害，而红桦能够通过“凋落老叶，萌发新叶”的途径来适应新的强光环境。 How to restore the vegetation of subalpine coniferous forest in eastern Qinghai-Tibet Plateau, and change the trend of ecological deterioration is a very important issue. Acclimation of tree seedlings to different and varing light environment affects to a great extent the successful regeneration and establishment of subalpine coniferous forests in southwestern China’s montane forest areas, because the ability to respond to such changing resource are commonly assumed to be critical to plant success, and have a growth advantage than others. In this paper, several species seedlings in Abies faxoniana community were chosed to study the response and adaptation to light intensity and the interspecific differences of adaptability in six shaded sheds (100, 55, 40, 25, 15 and 7% of full sunlight) in the Maoxian Ecological Station of Chinese Academy of Sciences. Our results could provide a strong theoretical evidence for understanding the forest succession laws of subalpine coniferous forests, and the survival and settlement of seedlings under plantations, and provide scientific direction for the production and management of seedlings, especially the comparative studies of the acclimation to light between the conifer and broadleaf trees could provide new ideas for how to integrate the broad-leaved trees into the artificial coniferous forest. Growth under different light intensity Light intensity plays an important role on plant growth. One field experiments was conducted to study the growth of tree seedlings of Picea asperata, Abies faxoniana, Betula albo-sinensis and Acer davidii under different light intensities. The results showed that plants under low light environment could increase the specific stem length (stem length/ stem dry mass), in order to effectively intercept light resources, while biomass greater allocation to the roots, could make plants under high light environment absorb more water, and avoid drought stress. During the first growing season, the relative growth rates (RGRs) of Betula albo-sinensis and Acer davidii had the greatest values under the 100% of full light, for 55% of Picea asperata, and for 25-40% of Abies faxoniana. However, in the second growing season the the relative growth rates of the two broad-leaved trees changed and were appropriate for 25-55% of full light, for 55-100% of spruce, and for 25-100% of fir. Thus, from the first year to the second year, two broad-leaved seedlings maybe more suitable to partly shading environment, and two coniferous seedlings would have an increase in light demand, which may be an increased root biomass investment. Because in this way, seedlings grown under high light could better maintain their internal water balance, and thus its growth would not be seriously affected by drought stress. In addition, serious shading would cause fir seedlings to die. Acclimation of physiology to light Plants could coexist in forest ecosystem by forming different strategies of light use. One field experiments was conducted to study the acclimation of tree seedlings to different light intensity of Picea asperata, Abies faxoniana, Betula albo-sinensis and Acer davidii. The results showed that the photosynthetic capacity of Picea asperata and Betula albo-sinensis exhibited a general tendency of increase with more light availability; but for Abies faxoniana and Acer davidii seedlings, their highest values of the same parameters were found under intermediate light regime (i.e. 25-55% of PFD relative to full sunlight). Plants under low light environment could increase the specific stem length (stem length/ stem dry mass), in order to effectively intercept light resources. Leaf nitrogen and chlorophyll content increased, while dark respiration rate and light compensation points decreased, all of which were adaptive response to the low light environment. On the contrary, plants under high light environment had the thicken leaves and palisade tissue, which was a protective response to high light. Phenotypic plasticity to light Phenotypic plasticity can be exhibited in morphological and physiological processes. Physiological characteristical adjustment is the main for plant adaptation to different light environment.The means of plasticity indexes for Betula albo-sinensis and Acer davidii seelings were greater than Picea asperata and Abies faxoniana, amplied that the two broad-leaved trees were much more adaptable to the environment. In addition, spruce had the higher adaptablity than fir. The findings supported the hypothesis that the ecological characteristics of the species determined the biological status and its biological habitat selection. Photoinhibition and photoprotection to light Compared with conifer, broad-leaved trees could better change leaf morphology and adjust biomass allocation to adapt to changing light environment. However, excess light can photoinhibit photosynthesis and may lead to photooxidative destruction of the photosynthetic appatus. Two field experiments were conducted to study the photoinhibition of photosynthesis. The results showed that when plants grown under high light environment or plants transferred from low to high irradiance, the four tree seedlings would undergo a period of photoinhibition. In four species, photoinhibited leaves could recover to initial photosynthetic rates when they were long-term planted under high light environment. However, when plants were suddenly exposed to high irradiance, this photoinhibition could not be reversible, may be the photosynthesis apparatus were (or partly) photooxidatively destructed.

增温对川西亚高山针叶林不同光环境下几种幼苗生长的影响

由于人类活动所引起的地球大气层中温室气体的富集已导致全球地表平均温度在20 世纪升高了0.6 ¡æ，并预测在本世纪将上升1.4-5.8 ¡æ。气候变暖对陆地植物和生态系统产生深远影响，并已成为全球变化研究的重要议题。位于青藏高原东部的川西亚高山针叶林是研究气候变暖对陆地生态系统影响的重要森林类型。森林采伐迹地和人工云杉林下作为目前该区人工造林和森林更新的两种重要生境，二者截然不同的光环境对亚高山针叶林不同物种更新及森林动态有非常重要的影响。 本文以青藏高原东部亚高山针叶林几种主要森林树种为研究对象，采用开顶式增温法（OTCs）模拟气候变暖来研究增温对生长在两种不同光环境下（全光条件和林下低光环境）的几种幼苗早期生长和生理的影响，旨在从更新角度探讨亚高山针叶林生态系统不同树种对气候变暖在形态或生理上的响应差异，其研究结果可在一定程度上为预测气候变暖对亚高山针叶林物种组成和演替动态提供科学依据，同时也可为未来林业生产管理者提供科学指导。 1、与框外对照相比，OTCs 框内微环境发生了一些变化。OTCs 框内与框外对照气温年平均值分别为5.72 ¡æ和5.21 ¡æ，而地表温度年平均值分别为5.34 ¡æ和5.04 ¡æ，OTCs 使气温和地表年平均温度分别提高了0.51 ¡æ和0.34 ¡æ；OTCs框内空气湿度年平均值约高于框外对照，二者分别为90.4 %和85.3 %。 2、增温促进了三种幼苗生长和生物量的积累，但增温效果与幼苗种类及所处的光环境有关。无论在全光或林下低光条件下，增温条件下云杉幼苗株高、地径、分支数、总生物量及组分生物量（根、茎、叶重）都显著地增加；增温仅在全光条件下使红桦幼苗株高、地径、总生物量及组分生物量（根、茎、叶重）等参数显著地增加，而在林下低光条件下增温对幼苗生长和生物量积累的影响效果不明显；冷杉幼苗生长对增温的响应则与红桦幼苗相反，增温仅在林下低光条件下对冷杉幼苗生长和形态的影响才有明显的促进作用。 增温对三种幼苗的生物量分配模式产生了不同的影响，并且这种影响也与幼苗所处的光环境有关。无论在全光或林下低光环境下，增温都促使云杉幼苗将更多的生物量分配到植物地下部分，从而导致幼苗在增温条件下有更高的R/S 比；增温仅在林下低光条件下促使冷杉幼苗将更多的生物量投入到植物叶部，从而使幼苗R/S 比显著地降低；增温在全光条件下对红桦幼苗生物量分配的影响趋势与冷杉幼苗在低光条件下相似，即增温在全光条件下促使红桦幼苗分配更多的生物量到植物同化部分—叶部。 3、增温对亚高山针叶林生态系统中三种幼苗气体交换和生理表现的影响总体表现为正效应（Positive），即增温促进了几种幼苗的生理活动及其表现：（i）无论在全光或林下低光环境下，增温使三种幼苗的光合色素含量都有所增加；（ii）增温在一定程度上提高了三种使幼苗的PSII 光系统效率（Fv/Fm），从而使幼苗具有更强的光合电子传递活性；增温在一定程度使三种幼苗潜在的热耗散能力（NPQ）都有所增强，从而提高幼苗防御光氧化的能力；（iii）从研究结果来看，增温通过增加光合色素含量和表观量子效率等参数而促进幼苗的光合作用过程。总体来说增温对幼苗生理过程的影响效果与幼苗种类及所处的光环境有关，增温仅在全光条件下对红桦幼苗光合过程的影响才有明显的效果，而冷杉幼苗则相反，增温仅在低光条件下才对幼苗的生理过程有显著的影响。 4、增温对三种幼苗的抗氧化酶系统产生了一定的影响。从总体来说，增温使几种幼苗活性氧含量及膜脂过氧化作用降低，从而在一定程度上减轻了该区低温对植物生长的消极影响；增温倾向表明使三种幼苗体内抗氧化酶活性和非酶促作用有所提高，从而有利于维持活性氧代谢平衡。但增温影响效果与幼苗种类所处的光环境及抗氧化酶种类有关，增温对冷杉幼苗抗氧化酶活性的影响仅在林下低光环境下效果明显，而对红桦幼苗抗氧化酶活性的影响仅在全光条件下才有明显的效果。 总之，增温促进了亚高山针叶林生态系统中三种幼苗的生长和生理表现，但幼苗生长和生理对增温的响应随植物种类及所处的光环境不同而变化，这种响应差可能异赋予了不同植物种类在未来气候变暖背景下面对不同环境条件时具有不同的适应力和竞争优势，从而对亚高山针叶林生态系统物种组成和森林动态产生潜在的影响。 Enrichment of atmospheric greenhouse gases resulted from human activities suchas fossil fuel burning and deforestation has increased global mean temperature by 0.6¡æ in the 20th century and is predicted to increase it by 1.4-5.8 ¡æ. The globalwarming will have profound, long-term impacts on terrestrial plants and ecosystems.The ecoologcial consequences arising from global warming have also become thevery important issuses of global change research. The subalpine coniferous forests inthe eastern Qinghai-Tibet Plateau provide a natural laboratory for the studying theeffects of climate warming on terrestrial ecosystems. The light environment differssignificantly between clear-outs and spruce plantations, which is particularlyimportant for plant regeneration and forest dynamics in the subalpine coniferous forests. In this paper, the short-term effects of two levels of air temperature (ambient andwarmed) and light (full light and ca. 10% of full light regimes) on the early growthand physiology of Picea asperata, Abies faxoniana and Betula albo-sinensis seedlingswas determined using open-top chambers (OTCs). The aim of the present study wasto understand the differences between tree species in their responses to experimentalwarming from the perspective of regeneration. Our results could provide insights intothe effects of climate warming on community composition and regeneration behavior for the subalpine coniferous forest ecosystem processes, and provide scientificdirection for the production and management under future climate change. 1. The OTCs manipulation slightly altered thermal conditions during the growingseason compared with the outside chambers. The annual mean air temperature andsoil surface temperature was 5.72 and 5.34 ¡æ (within the chambers), and 5.21 and5.04 ¡æ (outside the chambers), respectively. The OTCs manipulation increased airtemperature and soil surface temperature by 0.51 and 0.34 ¡æ on average, respectively.Air relative humidity was slightly higher inside the OTCs compared with the controlplots, with 90.4 and 85.3 %, respectively. 2. Warming generally stimulated the growth and biomass accumulation of thethree tree species, but the effects of warming on growth and development variedbetween light conditions and species. Irrespective of light regimes, warmingsignificantly increased plant height, root collar diameter, total biomass, componentbiomass (stem, foliar and root biomass) and the number of branches in P. asperataseedlings; For A. faxoniana seedlings, significant effects of warming on all the tested parameters (plant height, root collar diameter, total biomass, and component biomass) were found only under low light conditions; In contrast, the growth responses of B.albo-sinensis seedlings to warming were found only under full light conditions. Warming had pronounced effects on the pattern of carbon allocation. Irrespectiveof light regimes, the P. asperata seedlings allocated relatively more biomass to rootsin responses to warming, which led to a higher R/S. Significant effects of warming onbiomass allocation were only found for the A. faxoniana seedlings grown under lowlight conditions, with significantly increased in leaf mass ratio (LMR) and decreasedin R/S in responses to warming manipulation. The carbon allocation responses of B.albo-sinensis seedling to warming under full light conditions were similar with theresponse of A. faxoniana seedlings grown under low light conditions. Warmingsignificantly decreased root mass ratio (RMR), and increased leaf mass ratio (LMR)and shoot/root biomass ratio (S/R) for the B. albo-sinensis seedlings grown under full light conditions. 3. Warming generally had a beneficial effect on physiological processes of dominant tree species in subalpine coniferous forest ecosystems: (i) Warming markedincreased the concentrations of photosynthetic pigments in both tree species, but theeffects of warming on photosynthetic pigments were greater under low lightconditions than under full light conditions for the two conifers; (ii) Warming tended toenhance the efficiency of PSII in terms of increase in Fv/Fm, which was related tohigher chloroplast electron transport activity; and enhance non-radiative energydissipation in terms of in increase in NPQ, which may reflect an increased capacity inpreventing photooxidation; (iii) Warming may enhance photosynthesis and advancephysiological activity in plants by increasing photosynthetic pigment concentration,the efficiency of PSII and apparent quantum yield (Φ) etc. From the results, theeffects of warming on seedlings’ physiological performance varied between lightenvironment and species. The effects of warming on photosynthesis performance of B.albo-sinesis seedlings were pronounced only under full light conditions, while thephysiological responses of A. faxoniana seedlings to warming were found only underthe 60-year plantation. These results provided further support for the observationsabove on growth responses of seedlings to warming. 4. Warming had marked effects on antioxidative systems of the three seedlings.Warming generally decreased H2O2 accumulation and the rate of O2- production, andalleviated degree of lipid peroxidation in terms of decreased MDA content, whichalleviated to some extent the negative effects of low temperature on the plant growthand development in this region; Warming tended to increase the activities ofantioxidative enzymes and stimulate the role of non-enzymatic AOS scavenging,which helped to create an balance in maintaining AOS metabolites for the threeseedlings. Nevertheless, the effects of warming on antioxidative defense systems werepronounced only under the 60-year plantation for the A. faxoniana seedlings. Incontrast, the marked effects of warming on antioxidative defense systems for the B.albo-sinesis seedlings were found only under the full light conditions. In sum, warming is considered to be generally positive in terms of growth andphysiological process. However, the responses of growth and physiology performanceto warming manipulation varied between species and light regimes. Competitive and adaptive relationships between tree species may be altered as a result of responsedifferences to warming manipulation, which is one mechanism by which globalwarming will alter species composition and forest dynamics of subalpine coniferousforest ecosystems under future climate change.

青藏高原东部植物生态特征在季节性雪厚度梯度上的变化

本文以青藏高原东部的高山草甸为研究对象，设置早融、中间及晚融三个融雪部位，采用实验室测量、野外测量、野外样方调查相结合的 方法，从个体、种群和群落的水平上比较研究了高山雪场植物在同一雪场样地中不同融雪梯度上的特征变异及适应，结果表明： 从早融到晚融的梯度上，随着融雪时间的逐渐推迟，表土日温差降低，冻融交替的强度减弱，土壤水份逐渐增加，总N、总P、总K 以及 可溶性的N、P 和pH 变化不明显，土壤有机质及可溶性的K 和Ca 逐渐降低。冻融交替强度上的差异以及土壤水分差异被认为是融雪梯度上 影响植物生长的主要原因。 从早融到晚融的梯度上，伴随着生态因子的改变，几种常见植物的个体特征也发生相应的变化。首先，物候期推迟。植物开始生长的时间 一般要推迟将近二十天，但同一种植物在不同的融雪部位上的衰老期趋于一致，这预示着在晚融部位同一植物的生长期要缩短。其次，个体生 长特性发生改变。黑褐穗苔草（Carex atrofusca subsp. minor (Boott) T.Koyama）和西北黄芪（Astragalus fenzelianus Pet.-Stib.）的个体生长（株高、单株叶数、单叶面积和地上生物量）表现为逐渐增加的趋势；斑唇马先蒿（Pedicularis longiflora Rudolph var. tubiformis (Klotz.) Tsoong）和川西小黄菊（Pyrethrum tatsienense (Bur. et Franch.) Ling ex Shih.）则表现为逐渐降低的趋势；长叶火绒草（Leontopodium longifolium Ling）在融雪梯度上的变化趋势不明显。再次，从繁殖特性来看，大卫马先蒿（Pedicularis davidii var. pentodon Tsoong）的单株花数、单花种子数、种子千粒重及种子萌发率随融雪的推迟呈现为逐渐增加的趋势；圆穗蓼（Polygonum macrophyllum D.Don）的种子（小坚果）千粒重和萌发率也表现为逐渐增加，其余繁殖特征变化不明显。 在种群层次上，几个常见物种的分布格局随着融雪的推迟都发生一定的变化，基本上表现为从早融的集群分布到中间或晚融部位的随机分布。物种间的联结性也发生较大的变化，由早融部位的总体上的正关联逐步过度到晚融部位上的总体上的负关联。特定种对间的联结性也发生较大的变化。恶劣环境条件（如剧烈的冻融交替）的影响以及对恶劣条件适应被认为是分布格局及种间联结性发生变化的主要原因。 在群落层次上，物种多样性的变化表现为单峰曲线的格局，即在中间部位多样性最高。早融部位强烈的冻融交替和晚融部位缩短的生长季是早融及晚融部位物种多样性不高的重要原因。几乎所有的只出现在一个融雪部位（雪深级别）上的物种都发生在中间融雪部位。这说明，中等的雪深更有利于许多高山植物的存活，而过浅过深的积雪都不利于植物的生存。另外，相距较近的融雪梯度之间的物种相似性较大，而相距较远的梯度之间物种的替代率较高，物种的相似性较小。在群落的生物量方面，地上生物量随融雪的推迟而升高，地下生物量随融雪的推迟而下降，地上与地下生物量之总和随着融雪的推迟而下降，地下生物量与地上生物量之比随着融雪的推迟而下降。早融部位的地上生物量主要集中于地上0-10cm 的范围内，表明在早融部位植物地上部分有变矮的趋势；早融部位的地下生物量在土壤各深度分布相对较均一，而晚融部位地下生物量则主要集中于地下0-10cm 的范围内。生物量的变化趋势主要与雪场中各部位的土壤水分含量及地表日温度差异有关，是植物适应特定环境的结果。 To detect the plants’ responses to snow-cover gradients in an alpine meadow of eastern Tibetan plateau, laboratory method and field sample plot method were employed, and three gradeients （early-, medium and late-melting）were established in a natural snowbed. The measurements were carried out for two years and was done on three levels——individual, population and community. The results are shown as follows : From early- to late-melting gradients, daily ground temperature difference between day and night decreased, amplitude of freeze-thaw alternation weakened, soil organic matter contents and soluble K and Ca decreased, while soil water content increased. Total N, total P, total K，pH soluble N and soluble P kept constant from early- to late-melting portions. Among these factors, the changes of intense freeze-thaw alternation and soil water contents were considered as main factors affecting plants’ growth. From early- to late-melting portions, all phenological phases postponed, e.g. phase of plant emergence postponed almost twenty days. However, the same species’ individuals at different portions withered in step, which implied that the individuals at late-melting portion possessed shorter growing season length. Along the same gradient, both Carex atrofusca subsp. minor (Boott) T. Koyama and Astragalus fenzelianus Pet.-Stib. increased their individual growth, whereas Pedicularis longiflora Rudolph var. tubiformis (Klotz.) Tsoong and Pyrethrum tatsienense (Bur. et Franch.) Ling ex Shih. decreased their individual growth. Unlike the four plants mentioned above, Leontopodium longifolium L. did not show any evident change. As to reproductive charateristics, the flowers per individual, the number of seeds per flower, the thousand seed weight and the seed germination rate of Pedicularis davidii var. pentodon showed an increasing trend; and Polygonum macrophyllum D.Don also increased its thousand seed weight and seed germination rate along the same gradient. However, the other reproductive charateristics of Polygonum macrophyllum D.Don did not change significantly. At population level, the distribution pattern of several selected species changed from cluster pattern to random pattern as the snowmelt postponed. Overall association among the species changed from positive to negative along the same gradient. Further, interspecific association also changed evidently. Adverse circumstances such as intense freeze-thaw alternation were considered as primary factors resulting in changes of population distribution pattern and interspecific association. At the level of community, species diversity showed a pattern of a unimodal trend, i.e. the highest diversity occurred at medium snow depth，perhaps because of intense freeze-thaw alternation at early-melting portions and the shortest growing season at late-melting portions. Almost all species that only appeared at one snowmelt portion occurred at medium portion, indicating that medium snow depth was more suitable for many species’ survival. Species replacement from one snowmelt portion to its neighboring portion seldom took place. However, while distance between two portions became farther, species replacement between the two portions occurred more frequently. As for biomass, aboveground biomass increased from early- to late-melting portions, whereas belowground biomass, total biomass and the ratio of belowground to aboveground all decreased along the same snow gradient. A majority of aboveground biomass distributed in a height range of 0-10 cm, suggesting that height of plants inhabiting early-melting portion be shorter compared with other portions. In addition, belowground biomass at early-melting portion was evenly distributed at different soil depth in comparison with aboveground biomass, whereas belowground biomass at late-melting portion concentrated 0-10cm soil layer below ground. The changing trend of biomass was also related to two factors. One was soil water content, and the other topsoil temperature difference between day and night.