岷江中上游植被生态恢复过程中若干问题的探讨

　1．对四川省岷江上游地区（茂县）的锐齿槲栎（Quercus aliena var. acuteserrata）天然次生林进行研究，发现：(1) 坚果完好比例约在14% ~26%之间，完好坚果的发芽率和发芽势都比较高，但在天然状况下能够留存到翌年5月的坚果几乎没有。因此，实生幼苗的天然补充就受到了严重的限制。(2) 林缘的幼苗密度低于所有其它生境的 (P<0.05)，林中的幼苗密度最高，和林窗的比较有显著差异(P<0.05), 而和灌丛的比较则差异不显著（P>0.05）。在灌丛幼苗密度和林中以及林窗的比较都没有差异。动物对坚果的取食速度则是林中的最慢 (10.0%)，林窗和林缘的基本相同(分别为61.1%和66.5%)，取食速度都明显快于林中(P<0.01)。(3) 林中的幼苗在小于100 cm的各高度内都有大量分布，说明在林中树冠下幼苗是可以长期存在的，暗示在幼苗阶段的锐齿槲栎可能是耐荫的。(4) 在林中缺失幼树，在林缘则有包括幼树在内的完整的更新大小系列，表明林缘是更新的关键地点。(5) 在栎林的每一个大小级别上，萌生个体和实生个体都按各种比例伴生，说明导致萌生的干扰一直在发生，并可能在森林的更新中扮演重要角色;也说明该地区的锐齿槲栎林由萌生和实生起源的个体混合组成。 2．栎林是北半球温带森林的重要组成部分，因此栎林更新是全球森林更新研究的热点之一，而啮齿动物对栎林更新的影响则是关注的焦点。在2002~2003年，通过坚果标记研究了未被取食和遗弃坚果（即咬开后只有少部分被捕食后丢弃在林中的坚果）的健康比例，并定量测定了坚果的捕食、搬运、遗弃、丢弃、贮藏和留存等各种命运的比例和特点;对坚果也进行了各种人为的处理，以观测其命运和动物取食速度，发现：(1) 遗弃坚果中不健康坚果的比例比动物未取食的天然坚果中的比例有极显著的增加 (P>0.05)，暗示啮齿动物一般是通过咬开坚果来识别坚果健康与否并决定是否捕食。(2) 根据坚果命运和对照相比改变与否以及如何改变，各种人工处理坚果的命运可以分为 4 类：① 坚果命运没有任何显著改变;② 坚果被就地捕食的速度降低，搬运的速度不变，最终搬运坚果的比例增加而就地捕食坚果的比例降低，留存坚果的比例偶尔能增加至0.2%;③ 坚果就地捕食的速度几乎降至0，搬运的速度则在下降一段时间后又上升，并且搬运作用持续了相对长的时间，最终搬运坚果的比例大大增加，就地捕食坚果的比例很低，留存率为0;④ 坚果被搬运和就地捕食的速度和比例都降低，留存坚果的比例相应的大大增加，甚至可以达到50%。(3) 命运得到显著改变的②、③、④类坚果所承受的人工处理按照作用方式又可以分为主要作用于坚果化学状态（即气味浓度）的处理、主要作用于坚果物理状态（颜色、形态、有无附属物等）的处理以及使坚果处于不同颜色背景的处理;其中主要作用于坚果化学状态的处理对坚果命运具有最重大的改变，如胶带包裹处理和烧焦处理;其它各种主要作用于坚果的物理状态和所处背景的处理对其命运则也具有相对轻微的改变。这一试验结果可能证明：啮齿动物在对坚果进行识别和取食选择等活动时主要依赖于嗅觉来感知坚果的可食性，但是能感觉物理状态和所处背景的视觉也起一定程度的作用。(4) 啮齿动物对栎树坚果进行就地捕食、遗弃、搬运、异地捕食、丢弃、贮藏等作用，使各种命运的坚果都具有一定的数量比例和特点，也提供了动物影响栎林更新的多种可能途径。 3．人工干扰是任何退化生态系统中都始终存在的重大问题。除了明显的砍伐或者采摘外，人工践踏也是一种重要的干扰，特别是在茂县的山林普遍被牛马不断的放牧的情况下，这个干扰的后果就更加显著。为此研究了人脚踩踏的路上的白车轴草和未踩踏草坪上白车轴草在最大叶长、株高、芽高、构件数量、构件平均鲜重、死叶数量、根长等构型指标，根、茎、叶三者的生物量（干重）及比例等生物量指标，平均花序数量、花平均数量等繁殖指标方面的不同，发现踩踏使白车轴草植株：(1) 株高降低，芽高降低，最大叶长变小，平均每厘米的构件数量增加，构件平均鲜重降低，根长度减小，死叶数量增加。(2) 平均花序数量下降，每花序的花平均数量下降。(3) 但是在生物量的分配上，根和茎的生物量没有显著的下降，但是叶的生物量显著减低。因为白车轴草的茎可以不断克隆繁殖，所以踩踏对其存活可能没有太大的影响，只是造成了植株的矮化和密集化，根也变短;但是对种子繁殖有重大影响，反映在平均花序数量和每花序平均花数的显著下降上。在生物量的分配中，作为主要的同化器官，叶的生物量显著下降，而根茎比没有变化。这可能说明这样的克隆植物其物质流动是呈现网络化的特征，具有比较强的抗干扰能力。 4．连香树、油松、日本落叶松、华山松油松混合林是茂县地区的几种主要的已经营造的林型或者树种。为了了解其20年来的营林效果，运用样方调查的方法测量了这几种树种或者林型的胸径、持水量、凋落物现存量、密度等，评价了它们在生长、营业循环和水土保持等方面的差异。结果表明：日本落叶松具有生长缓慢，凋落物现存量大，涵养水分能力良好的树种，值得推广;油松生长迅速，凋落物现存量巨大，涵养水分能力一般的树种，也可以大力栽植;油松和华山松的混交林具有比较大的蓄积量和较好的涵养水分的能力，可以推广;而连香树则做为生长速度中等，成材率低，凋落物现存量小，涵养水分能力差的树种，不应该进一步推广。

浑善达克沙地植被恢复中几个问题的研究

浑善达克沙地位于内蒙古自治区锡林郭勒高原中部，是我国温带草原区最主要的沙地之一。由于沙质土壤特性和大陆性季风气候等自然条件的限制，长期过度放牧导致了沙地植被退化、固定沙丘活化等一系列环境问题，进而威胁到区域生态安全和可持续发展。恢复和重建退化了的沙地植被，防止沙漠化的进一步扩大已经刻不容缓。 本论文的目的是揭示沙地植被类型与环境的生态关系、沙地植物群落结构特点以及播种时期对沙地人工草地青贮玉米产量的影响，为在沙漠化防治中选择合适的治沙物种、制定合理的植被恢复方案、确定符合当地气候特点的人工草地最佳播种时间等提供理论依据。论文包括三方面的内容：1浑善达克沙地中部丘间低地植物群落分布与土壤环境因子关系;2浑善达克沙地中部植物群落物种多样性与土壤环境因子关系;3播期对浑善达克沙地青贮玉米产量的影响。 对在浑善达克沙地中部丘间低地上获取的102个植物群落样方进行了分析，按照样方中建群种和优势种的重要值把它们归属于28个植物群落类型。对102个群落样方进行去趋势典范对应分析（DCCA），结果表明DCCA排序轴第一轴主要代表地下水位的变化梯度;第二轴主要代表土壤的全氮含量和有机质含量的变化梯度;第三轴则代表土壤溶液的酸碱度值，即地下水位、土壤有机质、全氮含量和土壤溶液酸碱度影响沙地丘间低地植物群落的分布格局。 对流动－半流动沙丘、固定沙丘、丘间低地和淖尔边缘湖沼等四种生境的物种多样性研究结果表明，分布在流动沙丘－半流动沙丘的植物群落的物种丰富度指数和物种多样性指数最低，生态优势度指数较高，均匀度指数相对较高;固定沙丘的物种丰富度指数、物种多样性指数和均匀度指数较高，优势度指数较低;丘间低地和淖尔边缘湖沼的植物群落的物种丰富度指数，多样性指数低于固定沙丘的，但是高于流动－半流动沙丘的，优势度指数高于固定沙丘的，均匀度指数低于流动－半流动沙丘的。各个指数和土壤环境因子的相关分析表明，土壤溶液的酸碱度、土壤全氮和有机质含量与物种多样性有着较强的相关关系。 人工草地青贮玉米分期播种的实验结果显示:随着播期的推迟,英红玉米的地上生物量由2453±161kg/hm2降至1055±68kg/hm2;巴贮玉米的地上生物量由2159±65kg/hm2降至1016±70kg/hm2。两个品种的叶面积和株高都随着播期的推迟逐渐下降。5月27日和6月4日播种的青贮玉米的株高、叶面积和地上生物量显著高于6月11日和6月18日播种的青贮玉米的株高、叶面积和地上生物量（p＜0.05）。实验结果表明将当前生产实践中播种时间由6月中旬提前至5月底和6月初可以显著提高种植青贮玉米的产量。

浑善达克沙地稀树疏林草地生态系统研究：生物量、生产力与生态恢复途径

荒漠化是困扰我国干旱和半干旱地区的重要环境问题，我国的四大沙地也是荒漠化最为严重的地区，从生态学角度提高对沙地的认识，探明其生物量和生产力对于了解沙地生态系统的结构和功能是非常有意义的。本研究以浑善达克沙地为例，对沙地的植被特点、生物量和生产力以及退化沙地的恢复策略进行了探讨。 通过对浑善达克沙地进行的植被调查发现，浑善达克沙地的稀树疏林草地景观由草本层、灌丛和榆树疏林构成，彼此呈相间排列、交替出现的格局。在丘间低地以地带性的草本层植物占优势，灌丛主要出现在沙丘和丘间低地的过渡地段，地下水位较高的地方。榆树（Ulmus pumila）是沙地的优势树种，占沙地乔木的95％，榆树疏林主要在固定沙地稀疏分布，占沙地榆树总量的84％。胸径10-25 cm的榆树占60％，幼树少见，这和放牧干扰有关。沙地的稀树疏林草地是不同于周围草原地带的隐域植被，带有明显的超地带性，同时因受地带性气候的影响，兼有地带性特征。 在碳循环方面，为了估测沙地植被的碳存储潜力，我们对浑善达克沙地的生物量进行了估测。整个沙地被分为六种生境，分别求算生物量，然后汇总。对于其中的榆树生物量建立了异速生长关系进行估算。结果表明，浑善达克沙地植被的平均生物量为21.30 Mg ha-1，其中丘间低地的贡献为65％。从生活型上看，草本层的贡献占优势，而榆树的贡献很小，仅为10％。平均地下/地上生物量的分配比例为2.9。与草地生态系统相比，浑善达克沙地的生物量要高出90％，表明沙地植被是草原地带内的隐域植被，特殊的土壤水热条件使它具有更高的碳存储潜力。沙地的大范围恢复将使该碳库通过碳获取得以实现。 净初级生产力（NPP）是生态系统功能的重要体现，它可以反映植被碳固定的能力。为了了解稀树疏林草地NPP的特点，我们对浑善达克沙地六种生境的NPP分别进行了求算，然后汇总。浑善达克沙地植被的平均NPP为11.06 Mg ha-1 yr-1，各生境的贡献不同，以丘间低地的贡献最大，达65％。生活型上看，草本层植物占优势，乔木的贡献仅为1.3％。地下/地上NPP为1.7，降水利用效率达10.9。浑善达克沙地稀树疏林草地的NPP比草地生态系统的平均值高59％。NPP的研究结果表明，沙地植被是和周围地带性草原植被存在显著差别的，这种高生产力将伴随沙地的恢复而实现，并有可能对沙地地区的碳循环产生影响。 为了探索荒漠化防治的新途径，在浑善达克沙地巴音胡舒嘎查开展了为期5年的退化草地恢复试验。结果表明，通过“以地养地”的模式可以使退化草地充分利用潜在恢复力进行自然恢复，并取得了明显效果。开辟高效地，种植高产玉米，在草地得到恢复的同时，牲畜仍然有充足的草料供应，牧民生活水平也有所提高。这种适合半干旱地区环境条件的恢复模式比在同样地区造林要有效和经济。据此，文章最后探讨了当前荒漠化防治中存在的误区和今后荒漠化防治应采取的策略。

染色体加倍对忍冬生物学性状及其生态适应性的影响

忍冬（Lonicera japonica Thunb.）属忍冬科忍冬属，是一种重要的药用植物，其花蕾称为金银花（Flos Lonicerae），在我国已有1000多年的药用历史，具有清热解毒、凉散风热等功效。我们利用秋水仙素诱导二倍体“大毛花”品种茎尖选育出同源四倍体“九丰一号”品种，并在生产中发现花蕾产量显著提高，而药效成份含量是否发生变化了呢？四倍体忍冬表现出典型的器官巨大性，这些变化是否与其较强生态适应性之间存在联系呢？染色体加倍增强了忍冬的生态适应性，其生态修复功能如何呢？在本研究中，主要从以下几个方面进行了探讨：（1）染色体加倍对其叶片，茎、花蕾和花蕾产量及其药效成份等生物学性状的影响;（2）染色体加倍后植物对水分胁迫的响应;（3）染色体加倍后植物对热胁迫的响应;（4）除上述两个品种外，增加一个变异品种“红银花”，探讨3个忍冬品种对退化生态系统的修复功能。主要结果如下： 1. 通过测定根尖细胞染色体数目和使用流式细胞仪分析茎尖细胞DNA含量，表明四倍体忍冬（2n = 4x = 36）确实来自二倍体忍冬（2n = 2x = 18）的染色体加倍。四倍体忍冬气孔细胞大小显著大于二倍体，而气孔密度显著低于二倍体。四倍体忍冬没有光合“午休”，而二倍体存在明显的光合“午休”，这可能与其存在抗高温的叶片解剖结构特性有关。四倍体忍冬叶片较二倍体变大、变厚、变浓绿（较高叶绿素含量）。与二倍体相比，四倍体忍冬单位叶面积重量显著增高，表明其具有较强的生态适应性。四倍体忍冬单个花蕾的鲜重和干重均显著大于二倍体。连续3年的花蕾产量调查表明，四倍体显著高于二倍体。染色体加倍使其茎干粗壮、节间变短、新梢上着生花蕾数目增多及单个花蕾变大，这是其花蕾高产的生物学基础。对金银花的药效成份而言，染色体加倍不影响绿原酸的含量，但增加了木犀草苷的含量。结果表明，染色体加倍能增加金银花的产量和药效成份的含量，建议四倍体忍冬在药材生产中推广应用。 2. 水分胁迫显著降低二倍体和四倍体忍冬叶片的净光合速率、气孔导度和蒸腾速率。水分胁迫也降低电子传递速率、光系统II实际量子产量和光化学猝灭，而增加非光化学猝灭、总可溶性糖、脯氨酸和丙二醛的含量。四倍体忍冬对水分胁迫的响应表现为其叶片水势、气体交换、叶绿素荧光和有关代谢物含量的变化程度低于二倍体，并且复水后其恢复能力快于二倍体，表明染色体加倍增强了忍冬的抗旱能力。分析其主要原因，可能是由于四倍体植株总叶面积减少、单位叶面积重量增加、叶片表皮细胞和栅栏组织增大以及叶片表皮毛较浓密等形态解剖结构特性有关。结果表明，染色体加倍能增加忍冬植物的抗旱能力，而使其具有较强的生态适应性。 3. 二倍体和四倍体忍冬受48 ºC热胁迫处理6 h和恢复10 h，以及离体叶片45 ºC，50 ºC，55 ºC 水浴热胁迫3 min，应用叶绿素荧光成像系统研究了它们对热胁迫的响应。热胁迫显著降低了两个品种叶片的最大光化学效率、电子传递速率、光系统II实际量子产量和光化学猝灭，降低了四倍体的非光化学猝灭，而增加了二倍体的非光化学猝灭。热胁迫增加了两个品种叶片的总可溶性糖、脯氨酸和丙二醛的含量。四倍体受热胁迫的叶绿素荧光参数和有关代谢物的响应程度低于二倍体，以及其恢复程度快于二倍体，表明染色体加倍提高了抗热性。此外，叶绿素荧光成像的异质性也表明，四倍体的抗热能力大于二倍体。进一步的叶片解剖结构分析表明，四倍体叶片的表皮细胞变大、栅栏组织增厚、表皮毛较浓密等特点，是其抗热性强的主要原因。 4.根据以上的研究结果，通过四倍体忍冬生态修复功能的野外试验证明染色体加倍后其生态适应性变化。在本研究中，针对北京市门头沟区大面积不同类型的废弃地急需恢复植被和景观的问题，在恢复生态学理念的指导下，综合运用集成技术，将3个忍冬品种植物用于这些退化生态系统的恢复。在王平镇的公路下边坡（以碎石和矿渣为主）、煤矿、石灰窑和采石场4种类型废弃地建立生态修复的试验示范区。结果表明，在4个废弃地类型上引进的3个金银花品种，具有使示范区快速复绿、当年成景和群落快速形成的潜力，并具有对不同退化迹地的适应能力和恢复效果，其中四倍体忍冬效果更好些，这主要与其形态解剖结构和较强的生态适应性有关。

CHARACTERISTICS OF FATTY ACID METHYL ESTERS (FAMEs) AND ENZYMATIC ACTIVITIES IN SEDIMENTS OF TWO EUTROPHIC LAKES

Enzymatic activities and fatty acid methyl esters (FAMEs) in the sediments of two eutrophic lakes in Wuhan city were investigated. The results showed phosphatase and dehydrogenase activities in the lotus zone and plant floating bed zone were significantly lower than those in other sites, and urease activity was the highest where microorganism agents were put in. Fatty acid group compositions indicated the predominance of aerobic bacteria in the surface sediments in shallow lakes. The ratios of FAMEs specific for bacteria and Gram-positive bacteria exibited significant differences between the two lakes. The results of trans to cis indicated that the microorganisms in Lake Yuehu could adapt themselves to environmental stress better. The enzymatic activities and FAMEs showed differences in different sites, indicating that ecological restoration measures and environmental conditions could affect lake sediment to some extent. But the monitoring, work would be done in series to exactly evaluate the effect of the remediation measures.

Actinomycetes and earthy-musty odorous compounds in brackish fishponds in Tianjin, China

The presence of the odorous compounds, 2-methylisoborneol (MIB) and geosmin, as well as causative microorganisms in brackish intensive cultivation fishponds in Tianjin, China that had a severe earthy-musty odor were evaluated. The results revealed that MIB was the primary odorous compound present in the Tianjin fishponds, with a concentration ranging from 0.53-5302.7 ng.L-1. Furthermore, the concentration of MIB was found to be closely correlated with the gross biomass of actinomycetes in the water, which ranged from 10.67-1528.24 x 10(6) cfu.ml(-1). Therefore, the sequences of the 16 SrRNA and morphological characteristics of the actinomycetes in the brackish fishponds were investigated. The results revealed that the actinomycetes in the brackish fishponds included 9 species of common and dominant actinomycetes belonging to 4 genera. Of these genera, Streptomyces were the dominant species, and Streptomyces, Nocardioides and Micromonospora were the most common species in the fishponds evaluated. Next, the ability of each of the isolated Streptomyces to produce MIB was measured under laboratory culture conditions. Streptomyces Sp2 was found to have a strong ability to produce MIB, which indicates that this strain may be the primary source of the earthy-musty odor reported in brackish intensive cultivation fishponds in Tianjin, China.

Use of microbial community to evaluate performance of a wetland system in treating Pb/Zn mine drainage

The performance of a wetland system in treating lead (Pb)/zinc (Zn) mine drainage was evaluated by using the polyurethane foam unit (PFU) microbial community (method), which has been adopted by China as a standardized procedure for monitoring water quality. The wetland system consisted of four cells with three dominant plants: Typha latifolia, Phragmites australis and Paspalum distichum. Physicochemical characteristics [pH, EC, content of total suspended solid (TSS) and metals (Pb, Zn, Cd, and Cu)] and PFU microbial community in water samples had been investigated from seven sampling sites. The results indicated that the concentrations of Pb, Zn, Cd, Cu, and TSS in the mine drainage were gradually reduced from the inlet to the outlet of the wetland system and 99%, 98%, 75%, 83%, and 68% of these metals and TSS respectively, had been reduced in concentration after the drainage passed through the wetland system. A total of 105 protozoan species were identified, the number of protozoa species and the diversity index (DI) gradually increased, while the heterotrophic index (HI) gradually decreased from the inlet to the outlet of the wetland system. The results indicated that DI, HI, and total number species of protozoa could be used as biological indicators indicating the improvement of water quality.

Research progress on algae of the microbial crusts in and and semiarid regions

Microbial crusts are attracting much interest in view of their possible uses in environmental conservation and ecological restoration of the and and semiarid regions. Because algae play an irreplaceable important role in the early formation and the strengthening of microbial crusts, they are paid much more attention to than other cryptogams. In this paper, an overview of the current knowledge on the fine structure and development of microbial crust, focusing on the algal biomass, vertical distribution, succession, influential factors on algae, cohesion of soil stabilization, cementing mechanism for soil particles and the microalgal extracellular polymers is given, with particular emphasis on the authors' researches, and some prospects are put forward as well.

黄土丘陵区人工刺槐林土壤活性有机碳与碳库管理指数演变

土壤碳库管理指数是表征土壤碳变化的重要量化指标,研究黄土丘陵区人工刺槐林土壤活性有机碳与碳库管理指数的变化过程对认识该地区生态恢复过程中土壤质量的演变及其效果评价具有重要意义。【方法】采用时空互代法,以典型侵蚀环境纸坊沟流域生态恢复过程中不同年限的人工刺槐林为研究对象,选取坡耕地和天然侧柏林为参照,分析了植被恢复过程中土壤有机碳(TOC)、活性有机碳(LOC)、非活性有机碳(NLOC)及碳库管理指数(CPMI)的演变特征,并运用相关和回归分析方法对生态恢复过程中碳库各组分和恢复年限进行拟合。【结果】营造刺槐林可以显著增加土壤碳库各组分含量,并随恢复年限呈显著线性关系,50a时TOC、LOC、NLOC和碳库指数(CPI)分别较坡耕地增加271%、174%、467%和271%,其中NLOC增加速率略高于LOC,表明植被恢复增加的土壤碳素绝大多数以非活性形态贮存起来,而为了满足生物生长所必须的活性物质来源,土壤碳库必须维持一定的活度状态来满足碳素的动态转化平衡,碳库管理指数在营造刺槐林初期显著降低,随后先增加后降低,与刺槐林生长特性密切相关;但与天然林相比差距仍然较大,恢复50a时TOC、LOC和NLOC仅...

黄土丘陵区退耕撂荒地土壤微生物量演变过程

土壤微生物量是表征土壤生态系统中物质和能量流动的重要参数,研究黄土丘陵区坡耕地撂荒后微生物量及其活性的变化过程对认识该地区生态恢复过程中土壤质量的演变及其效果评价具有重要意义。【方法】采用时空互代法,以典型侵蚀环境纸坊沟流域生态恢复过程中不同年限的撂荒地为研究对象,选取坡耕地和天然侧柏林为参照,通过室内测试分析,并运用统计和相关分析等方法,研究坡耕地撂荒后土壤微生物量、呼吸强度、代谢商(qCO2)及土壤理化性质的演变特征。【结果】侵蚀环境下的坡耕地土壤微生物量含量偏低,土壤理化性质较差,撂荒后理化性质得到显著改善,微生物量碳(Cmic)在撂荒1a后显著增大,前7a较为剧烈,增幅较大,随后呈波动式上升,50a达到最大值;微生物量氮(Nmic)在撂荒初期增长缓慢,40a时才达到显著水平,微生物量磷(Pmic)在撂荒初期显著降低,5～7a达到最低值,随后逐渐上升,20～25a时和坡耕地没有显著差异,50a时达到最大值。撂荒50a时土壤Cmic、Nmic和Pmic分别较坡耕地增加166%、146%和52%,但仅为侧柏林的43.42%、45.06%和51.47%。呼吸强度在撂荒初期迅速增加,随后趋于稳定,与侧柏...

黄土丘陵区延河流域潜在植被分布预测与制图

潜在植被的分布预测与制图对植被恢复规划具有重要的指导价值.利用广义相加模型(generalized additive model,GAM),结合GIS空间分析技术和环境梯度分层采样技术,为延河流域24个地带性物种建立了分布模型,并在考虑群落内部物种种间关系及其分布概率的基础上,对物种分布进行运算,模拟预测了延河流域37种植物群落的分布状况和延河流域的潜在植被分布.结果表明:研究区植被分布预测值与实际调查值间的差异不显著,预测的植被空间分布较好地反映了延河流域潜在的植被分布状况,表明该模型具有较好的预测能力,对于区域植被恢复的目标设定和恢复规划具有重要意义.

长白山次生林群落动态及其生态恢复

该文结合中国天然林保护工程的新形势和森林可持续发展的要求，运用林学、群落生态学、恢复生态学、生物多样性保护等原理和方法，以长白山区广泛分布于中低海拔的次生林为研究对象，通过大量的野外调查、室内分析和资料收集，针对实际深入研究和评价了在自然恢复和人为抚育管理模式下次生林的动态及其过程的一些重点问题，进而揭示了在不同管理模式下次生林群落组成、结构、物种多样性、种群分布格局、种间联结等演变规律及其对森林稳定性的贡献和维持机理，丰富和补充了阔叶红松林的系统研究内容，为林区森林的发展提供了模式和依据.

三种豆科灌木对干旱胁迫的响应与适应

干旱胁迫是全球范围内影响植物生存、生长和分布的重要环境因子。岷江上游干旱河谷区，由于生态环境的脆弱性和长期人类活动的干扰和过度利用，导致植被严重退化，水土流失加剧，山地灾害频繁，干旱化和荒漠化趋势明显。这种趋势若不能遏制，将严重阻碍区域社会经济的快速协调发展，并且威胁成都平原地区的发展和长江中下游地区的生态安全。因而开展干旱河谷生态恢复研究成为解决这些问题的关键。水分匮乏是限制干旱河谷生态恢复的关键因子，在全球气候变化的背景下，干旱胁迫在区域尺度上可能会更加严重，并使干旱河谷的生态环境更加恶化。因此，深入研究干旱河谷乡土植物对干旱胁迫的响应和适应机理，具有非常重要的理论和实践意义。 本论文以岷江上游干旱河谷的三种乡土豆科灌木，白刺花（Sophora davidii）、小马鞍羊蹄甲（Bauhinia faberi var. microphylla）和小雀花（Campylotropics polyantha）理论和实践意义。为研究对象，在人工控制条件下设计了4-5个连续性干旱胁迫处理，系统地研究了灌木幼苗的生长、生物量积累和水分利用效率（WUE）、形态结构和生理过程等对干旱胁迫的反应，揭示了幼苗的干旱适应能力及种间差异。主要研究结论如下： 1) 灌木生长和繁殖对干旱胁迫的反应 在干旱胁迫下，幼苗生长速率显著减小，叶片衰老和脱落比率增大，这些变化随着胁迫强度的增加具有累积效应。叶片比茎对干旱胁迫的反应更敏感。在严重干旱胁迫下，幼苗的有性繁殖被限制，但在中等程度干旱胁迫下，幼苗的有性繁殖能力被提高。 2) 灌木生物量积累及其分配和WUE对干旱胁迫的反应 在干旱胁迫下，灌木各器官的生物量都显著减小，但是生物量的分配侧重于地下部分，使得根茎比在干旱条件下增大。幼苗的耗水量（WU）随着干旱胁迫的增加而显著减少。白刺花和小马鞍羊蹄甲WUE在干旱胁迫下降低；小雀花的WUE在中等干旱胁迫下升高。 3) 灌木叶片结构特征对干旱胁迫反应 白刺花叶片具有较为典型的旱生型结构，而小马鞍羊蹄甲和小雀花则为中生型结构。在1至2年的干旱胁迫下，灌木叶片结构组成未发生本质性的改变，主要是细胞大小的变化。在中等和严重干旱胁迫下，叶肉组织厚度明显减小；并且气孔和表皮细胞面积也显著减小，气孔和表皮细胞密度显著增大；叶肉细胞层数、P/S值、表皮厚度等无显著变化。 4) 灌木对干旱胁迫的生理响应 气体交换参数和叶片相对含水量（RWC）在中等干旱胁迫下发生了明显的改变，而叶绿素荧光参数和光合色素含量在严重干旱胁迫下才发生显著变化。在干旱胁迫下，净光合作用速率（Pn）、气孔导度（gs）和RWC呈下降趋势，而叶片温度（Tl）呈增加趋势，蒸腾速率（Tr）的变化不明显。除了日最大Pn减小以外，干旱胁迫对气体交换参数的日变化无显著影响，但是对光合-光响应曲线有显著的影响，使有效光合时间缩短。在严重干旱胁迫下光系统受到损害而代谢减弱，PSⅡ中心的内禀光能转换效率（Fv/Fm）、量子产量（Yield）、光化学淬灭参数（qP）显著降低，而非光化学淬灭参数（NPQ）明显增加。气孔限制和非气孔限制对Pn的影响与干旱胁迫强度有关。在中度胁迫下，气孔限制起主导作用，在严重胁迫下非气孔限制起主导作用，40% FC水分条件可能是灌木由气孔限制向非气孔限制的转折点。 5) 灌木对干旱胁迫的适应能力及其种间差异 三种灌木对干旱胁迫具有较好的适应能力，即使在20% FC，幼苗未因干旱胁迫III而死亡；80% FC适宜于幼苗生长。白刺花生长速率慢，耗水量较少，具有较强的耐旱和耐贫瘠能力，并具有干旱忍受机制，能够在较干旱的环境中定居和生长。小马鞍羊蹄甲和小雀花，生长快，水分消耗量较大，尤其是小雀花，对干旱胁迫的忍受能力较弱，具有干旱回避机制，因而适宜于在较为湿润的生境中生长。综合分析表明，生长速率较慢的物种抗旱能力较强，其更适宜于作为干旱地区植被恢复物种。 Drought is often a key factor limiting plant establishment, growth and distribution inmany regions of the world. The harsh environmental conditions and long-termanthropogenic disturbance had resulted in habitat destruction in the dry valley ofMinjiang river, southwest China. Recently, it tended to be more severe on the vegetationdegradation, soil erosion and water loss, natural disaster, as well as desertification, whichimpact on regional booming economy and harmonious development, and would be verydangerous to the environmental security in the middle and lower reaches of Yangzi River.Therefore, ecological restoration in the dry valley is one of the vital tasks in China. Waterdeficit is known to affect adversely vegetation restoration in this place. Moreover, in thecontext of climate change, an increased frequency of drought stress might occur at aregional scale in the dry valleys of Minjiang River. The selection of appropriate plantingspecies for vegetation restoration in regard to regional conditions is an important issue atpresent and in further. The research on responses of indigenous species to drought stresscould provide insights into the improvement of the vegetation restoration in the dry valleys of Minjiang River. In this paper, the responses of three indigenous leguminous shrubs, Sophora davidii,Bauhinia faberi var. microphylla and Campylotropics polyantha, to various soil watersupplies were studied in order to assess drought tolerance of seedlings, and to compare interspecific differences in seedlings’ responses to drought stress. The results were as follows: 1 Growth and reproduction of shrubs in response to drought stress Seedling growth reduced significantly while leaf senescence accelerated underdrought stress, the cumulative responses to prolonged drought were found. The capacityfor reproduction was limited by severe drought stress, and improved by moderate droughtstress. Leaf responses were more sensitive than shoot to various water supplies. 2 WUE, biomass production and its partitioning of shrubs in response to drought stress Drought stress reduced significantly the total dry mass and their components ofseedlings, and altered more biomass allocation to root system, showing higher R/S ratiounder drought. Water use (WU) and water-use efficiency (WUE) of both S. davidii and B.faberi var. microphylla declined strongly with drought stress. The WU C. polyantha ofalso declined with drought stress, but WUE improved under moderate drought stress. 3 Anatomical characteristics and ultrastructures of leaves in response to drought stress There were xeromorphic for S. davidii leaves and mesomorphic for B. faberi var.microphylla and C. polyantha at the all water supplies. The foundational changes in leafstructures were not found with drought stress. However, mesophyll thickness, the areas ofstomatal and epidermis reduced slightly while the densities of stomatal and epidermisincreased under severe drought stress. Variations in these parameters could mainly be duoto cell size. Other structures did not displayed significant changes with drought stress. 4 Physiological responses of shrubs to drought stress The gas exchange parameters and leaf relative water content (RWC) were affectedby moderate stress, while chlorophyll fluorescence and chlorophyll content were onlyaffected by severe stress. Drought stress decreased net photosynthesis rate (Pn), stomatalconductance, light-use efficiency and RWC, and increased leaf temperature. Therespiration rates (Tr) were kept within a narrower range than Pn, resulting in aprogressively increased instantaneous water use effiecency (WUEi) under drought stress.Moreover, drought stress also affected the response curve of Pn to RAR, there was adepression light saturation point (Lsat) and maximum Pn (Pnmax) for moderate andsevere stressed seedling. However, diurnal changes of gas exchange parameters did notdiffer among water supplies although maximum daily Pn declined under severe stress.VISevere stress reduced Fv/Fm, Yield and qP while increased NPQ and chlorophyll content.Photosynthetic activity decreased during drought stress period due to stomatal andnon-stomatal limitations. The relative contribution of these limitations was associatedwith the severity of stress. The limitation to Pn was caused mainly by stomatal limitationunder moderate drought stress, and by the predominance of non-stomatal limitation undersevere stress. In this case, 40% FC water supply may be a non-stomatal limitation 5 Interspecific differences in drought tolerance of shrubs Three shrubs exhibited good performance throughout the experiment process, evenif at 20% FC treatment there were no any seedlings died, 80% FC water supply wassuitable for their establishment and growth. S. davidii minimized their water loss byreducing total leaf area and growth rate, as well as maintained higher RWC and Pncompared to the other two species under drought stress, thus they might be more tolerantto the drought stress than the other two species. On the contrary, it was found that C.polyantha and B. faberi var. microphylla had higher water loss because of their stomatalconductance and higher leaf area ratios. They reduced water loss with shedding theirleaves and changing leaf orientation under drought stress. Based on their responses, thestudied species could be categorized into two: (1) S. davidii with a tolerance mechanismin response to drought stress; (2) C. polyantha and B. faberi var. microphylla withdrought avoidance mechanism. These results indicated that slow-growing shrub speciesare better adapted to drought stress than intermediate or fast-growing species in present orpredicted drought conditions. Therefore, selecting rapid-growing species might leavethese seedlings relatively at a risk of extreme drought.

岷江干旱河谷三种蔷薇植物繁殖更新研究

繁殖更新是植物生活史的重要阶段，在退化生态系统中，植物繁殖更新能力往往较差，是植被恢复的限制环节，因而也成为恢复研究重点和核心。本研究选择岷江干旱河谷广泛分布的三种蔷薇：多苞蔷薇（R. multibracteata）、黄蔷薇（R. hugonis）和川滇蔷薇（R. soulieana）为研究对象，通过野外调查，在查明其生长、繁殖更新状况的基础上，采用控制和模拟实验，对种子和幼苗阶段进行了深入研究，综合分析更新潜力，并提出相对应的促进更新和植被恢复措施。主要结论如下： 1）三种蔷薇在岷江干旱河谷广泛分布，生长和繁殖状况良好，结实量大。各生长指标：株高、基径和冠幅，繁殖指标：结实数量、重量和单果重量都具有显著的空间差异性。基径对多苞蔷薇结实量影响最大；而冠幅对黄蔷薇结实量影响最大。海拔和纬度是对蔷薇生长和繁殖影响最大的环境因素，随着海拔和纬度的升高，植株生长更高大，结实量增加；坡度和坡向对其生长和繁殖也有一定影响，随着坡度 和坡向增加，蔷薇生长和结实受到抑制。 2）三种蔷薇在岷江干旱河谷更新现状不佳, 但更新潜力大。活力种子比率低，动物取食以及两年生幼苗的大量死亡是蔷薇更新的主要限制因素。多苞蔷薇和黄蔷薇的结实率低，川滇蔷薇较高。三种蔷薇种子产量大，但种子质量较差，更新具有充足的种源。三种蔷薇都能形成持久种子库，种子库中种子总量大，但有效种子少，黄蔷薇被动物啃食的比例很高，多苞蔷薇和川滇蔷薇也有一部分种子受到动物破坏。三种蔷薇幼苗库组成特征表现为，当年生幼苗所占比例很高，年龄较大幼苗所占比例小。 3）三种蔷薇都具有不同程度休眠，未经处理种子的发芽率极低。黄蔷薇休眠程度最深，为深度生理休眠；多苞蔷薇为中度生理休眠；川滇蔷薇为非深度生理休眠。三种蔷薇种子在形态上发育成熟，种皮具有透水性。蔷薇果果肉和瘦果中含有抑制物质，其浸泡液抑制了油菜种子萌发，果肉抑制作用更强，果肉和瘦果浸泡液的抑制程度分别为：川滇蔷薇>黄蔷薇>多苞蔷薇。切割和硫酸腐蚀提高了川滇蔷薇种子的发芽能力，而对多苞蔷薇和黄蔷薇没有影响。完全去除瘦果果皮和种皮提高了多苞蔷薇种子发芽率，但对黄蔷薇没有影响。赤霉素和烟水对蔷薇种子萌发没有促进作用。三种蔷薇打破休眠所需低温层积时间分别为：黄蔷薇>多苞蔷薇>川滇蔷薇。对于多苞蔷薇和川滇蔷薇，层积前对种子进行硫酸腐蚀或暖温层积能缩短低温层积时间，提高发芽率。对于多苞蔷薇，变温层积中暖温层积和低温层积具有一定的负补性，即延长暖温层积可以缩短种子萌发对低温层积的需要。 4）多苞蔷薇种子形态特征和种子休眠与萌发在不同海拔梯度间存在较大差异。种子采集时间、采集季节和干藏影响多苞蔷薇和川滇蔷薇的种子休眠。多苞蔷薇果实大小、种子大小和千粒重、种皮厚度随海拔升高而增加，而种子饱满率和活力随海拔升高而降低，种子休眠程度也随海拔升高而增加。种皮厚度与种子大小、千粒重成正相关关系，硫酸腐蚀后的种子经过不同时间的低温层积后，种子发芽率与种皮厚度、种子大小、千粒重、海拔成正相关关系。2006 年采集川滇蔷薇和多苞蔷薇种子休眠程度较2005 年低。种子休眠随种子年龄增加而减弱。高温和干旱能减轻多苞蔷薇和川滇蔷薇种子休眠。 5）三种蔷薇的生长和生物量积累在干旱胁迫条件下受到抑制，而生物量分配、叶片形态特征和水分利用特征等都发生了变化。三种蔷薇的根、茎、叶各器官生物量以及总生物量等在干旱胁迫下明显减小，叶片脱落数量增加。在干旱胁迫条件下，较多的生物量分配到地下部分，从而这使R/S 明显增加。比叶面积（SLA）和冠层面积比（LAR）对干旱胁迫的反应不敏感，仅有部分物种在干旱胁迫条件下发生了变化，并且其变化特点在不同年龄幼苗之间有一定差异。干旱胁迫对WUE 的影响在不同物种间存在差异。多苞蔷薇和黄蔷薇的WUE 随着干旱胁迫的增加而增大， 而川滇蔷薇的WUE 则随干旱胁迫增加而减小。在干旱胁迫条件下，多苞蔷薇和黄蔷薇叶片脱落量和生物量减小幅度较川滇蔷薇大，表明其抗旱能力较强。在干旱胁迫条件，三种蔷薇两年生幼苗的生物量减小幅度较当年生幼苗小，表明两年生幼苗的抗旱能力更强。 6）两种植被恢复措施中，幼苗移栽比播种具有更好的植被恢复效果。播种后，蔷薇种子的发芽率较高，但出苗率都很低，即使出苗，幼苗也几乎在一月内全部死亡。 三种微生境条件下（灌木、半灌木和裸地），种子出苗和幼苗成活没有差异。移栽幼苗总体死亡率都比较低，小于20％。特别是两年生幼苗死亡率更低，小于2％。移栽后的幼苗生长状况良好，在整个生长季中，各生长指标不断增加。生境对幼苗的存活率没有显著影响，但对于幼苗的生长和生物量积累有一定影响，裸地更有利于幼苗生长和生物量积累。与当年生幼苗相比，两年生幼苗具有更高的成活率。总之，三种蔷薇在干旱河谷分布广泛、生长繁殖状况良好，结实量大，具有丰富种源，繁殖更新潜力大，但繁殖更新状况不佳；种子散布后动物对种子的取食、种子的深度休眠过程、种子出苗以及当年生幼苗的存活和定居是更新的主要限制环节。水分是影响结实、种子休眠解除和萌发，幼苗存活和定居的最主要的限制因素。在植被恢复中，应在种子成熟季节大量采集种子，在室内打破休眠后进行人工播种，培育两年生幼苗，通过幼苗移栽方式进行植被恢复。川滇蔷薇应栽种在相对湿润的过渡区，而多苞蔷薇和黄蔷薇可以应用于核心区植被恢复。 Regeneration is an important phase in plant life cycle. It has been a key component of ecological restoration in degradation ecosystem in which plants commonly has poor regeneration. In this paper, we investigated the natural growth, propagation and regeneration status of native three rose species, Rosa multibracteata, R. hugonis and R. soulieana, and analysis the limitation in seed germination and seedling establishment stages. Advice on facilitating the use of these plants in restoration based on the results has been proposed. The results were as follows: 1) Three rose plants widely distributed in the dry valley of the Minjiang River, and made a good performance in growth and propagation. There were significant spatial differences in each growth parameter, such as ramet height, basal diameter, crown diameter and propagation parameters including hip number of a clump, hip mass of a clump and a hip mass. Basa diameter was the most important growth parameter influencing fruit number for R. multibracteata and crown diameter was for R. hugoni. Altitude and latitude had the greatest effect on the growth and propagation of rose plants among environmental conditions. Each parameter of growth and propagation increased with the increase of altitude and latitude. In addition, the increase of slope and aspect limited the growth and propagation. 2) Three rose plants had poor natural regeneration, but great regeneration potential. Low seed viability, predation and higher mortality of current year old seedlings were the limitation in regeneration. R. multibracteata and R. hugonis had higher fruiting rates than R. souliean. All three plants produced a great number of seeds, while their viability was poor. Three rose plants had persistent seed banks, with high total seed number but very low viable seed density. Predation was most severe in R. hugonis, and it also existed to some degree in R. multibracteata and R. soulieana. The seedling age-structure was characteristic of current-year seedlings predominating and few older seedlings were observed. 3) Three rose seeds were dormant and untreated seeds germinated with very low germination percentages. The rose seeds had morphological mature embryos, and achenes were permeable. Some inhabit substances existed in hips and achenes for the extracts of hips and achenes inhibited germination of Brassica campestris. The inhibition effect of the extracts of three rose hip and achenes was R. soulieana>R. hugonis>R. multibracteata. Mechanical and H2SO4 scarification increased R. soulieana germination but had no effect on germination of R. hugonis and R. multibracteata seeds. Full removal of pericarp and testa improved the germination of R. multibracteata but did not affect R. hugonis germination. GA3 and smoke water had no positive effect on rose seed germination. The periods of cold stratification required to released seed dormancy was R. hugonis > R. soulieana >R. multibracteata. H2SO4 scarification and warm stratification shortened cold stratification to release dormancy for R. soulieana and R. multibracteata. Warm stratification had complementary effect for cold stratification, i.e. the longer warm stratification seeds received, the shorter cold stratification were required to obtain the same germination percentage. Three rose seeds had different kinds of dormancy; R. hugonis has deep physiological dormancy, R. multibracteata with intermediate physiological dormancy and R. souliean non-deep physiological dormancy. 4）The seeds traits and dormancy of R. multibracteata showed significant difference across altitudes. Year and season of seed collection had significant effect on seed dormancy for both R. souliean and R. multibracteata. Hip size, seed size, seed weight, seed coat thickness and seed dormancy level increased with the increase of the altitude. There were positive relations between seed coat thickness with seed size and seed weight. Germination percentage of seeds treated with H2SO4 scarification following different periods of cold stratification showed positive relation with seed coat thickness, seed size, seed weight and altitude. Seeds of R. souliean and R. multibracteata collected in 2006 had low dormancy level than those collected in 2005. Seed dormancy decreased with increasing seeds age. High temperature and drought were associated with low dormancy level. 5) Seedling growth, the total dry mass and their components of seedlings were reduced, while leaf senescence accelerated under drought stress. More biomass allocation to root system resulted in higher R/S ratio under drought. Water-use efficiency (WUE) of R. multibracteata and R. hugonis increased, while it declined for R. soulieana under drought stress. R. soulieana seedlings had poor drought-resistance capacity it had more senescent leaves, and its reduction of biomass was stronger than two other rose plants under drought. The reduction degree of one year old seedlings under drought stress was slighter than that of current year seedlings. Therefore, one year old seedling was more drought-resistent compared to current year seedlings. 6）Planting seedlings may have better effect in comparison with direct seeding. Most seeds germinated after seeding, but seedling emergence was very low. More than 80 % seedlings from direct seeding died within a months after emergence. Seedling emergence and survival rate did not show difference among microhabitats. Mortality rates of seedlings artificially planted in microhabitats were general lower than 20 %, and the mortality rate of one year old seedlings was lower than 2 %. Each grow parameter including plant height, leaf number and branch number continually increased after planting. Microhabitat type had effect on the growth parameter and biomass production, but it did not influence the seedling survival. Bare land tended to facilitate seedling growth. One year old seedlings had higher survival rate than current year seedlings. In conculsion, the three rose had wide distribution in the dry valley of the Minjiang River. They produced many seeds and had tolerance to drought stress to some degree. But they had poor regeneration in habitats may be caused by predation, seed dormancy，and high mortality in current year seedlings. We recommend that rose plants should be utilized in restoration by planting two-year old seedlings in spring. A large quantity of seeds should be collected artificially in autumn, release seed dormancy in room, and then cultivate two-year old seedlings by seeding in particular container. R. soulieana seedling probably be planted in transition area, and R. multibracteata and R. hugonis can be used in core area of the dry valley of the Minjiang River.

高寒湿地自然保护区多核心动态分区研究——以四川若尔盖湿地国家级自然保护区为例

中国拥有92466 Km2的各类高原湿地，具有湿地退化、过度放牧等相似特征，保护与利用矛盾突出。高寒湿地保护区尽管在制度上以核心区、缓冲区来约束当地的放牧等外来干扰行为，但在实际管理中却不能起到应有的作用。 本研究以四川若尔盖湿地国家级自然保护区为例，应用3S技术，建立保护区多功能动态分区工作流模型，通过不同植被类型的识别和空间特征分析、不同动物类群在上述植被生境中的时空分布特征分析、保护区主要干扰因素的时空分布特征分析，突出对保护区主要保护对象（湿地生态系统）的保护，对保护区进行管理分区，依据野生动物利用特征和植被生长特征对核心区进行年周期动态利用，缓解保护与发展的矛盾，促进保护区的优化管理。 应用归一化植被指数（NDVI）与植被盖度的相关性，将归一化植被指数（NDVI）转化为植被盖度指数（MDVI），结合保护区牧场划分和时空利用特征专家经验，结果表明，MDVI值在1-139之间主要代表着水体、裸地、沙地等；MDVI140-256为草地和高山灌丛；MDVI210是当地夏牧场和秋冬牧场的划分区间值。 合理的区划需要资金、技术和政策的支持，为保证保护区多核心动态分区的实施，本研究提出了生态工程、牧业发展方式转变、湿地特色产业发展、湿地政策、社区参与和科技支撑等六大保障措施。 In China, 92466 Km2 highland or frigid wetlands are (were) facing major management problems, such as wetland degradation and overgazing. Conflict between conservation and utilization on those wetlands can be found anywhere today. Although many nature reserves have been setup for protection of frigid wetland, and core and buffer zone has been declared to forbid any kinds of disturbance, local farmers still use these areas for grazing. As an example by Sichuan Roige Wetlands National Nature Reserve(SRWNRR), we set up a 3S flow model to analyze the character of year-round distribution patters of vegetation, wildlife, and grazing. Combined and overlapped these characters together, we select multi-core zone and buffer zone, then define a dynamic management period in different zone to optimize protection wetland in the reserve. Normalized Difference Vegetation Index（NDVI）is highly related with coverage of vegetation. When convert NDVI to MDVI (coverage index, 1-256), index 139 and 210 can be as inflexion to distinguish among water/sand/bared land, summer pasture, and autumn / winter pasture. We use these to select different layers and analyze grazing pattern. To be more realistic, we put forward some strategies to support our multi-core and dynamic management of wetland in Roige, including ecological restoration engineering, changing of stock raising industry, changing of wetland policy, community based management and technology renovation supports.