FEEDING AND VOCAL BEHAVIORS OF BLACK GIBBONS (HYLOBATES-CONCOLOR) IN YUNNAN - A PRELIMINARY-STUDY

Feeding and vocal behaviours of wild black gibbons (Hylobates concolor) were observed from 1987 to 1989 in south-western Yunnan, notably H. concolor jingdongensis at Mt. Wuliang (24-degrees 18-42'N, 100-degrees 30-50'E) in the early spring of 1989. 12 plant species were observed to have been eaten by the gibbons; these included tree species, lianas and epiphytes. Approximately 21 % of feeding time was devoted to eating fruits, 61 % to leaf buds and shoots, 7 % to flowers and 11 % to leaves. The gibbons preferred fruits to leaves even though they commonly ate leaves. In this study, the morning songs (duet and solo), reponsive (territorial) songs, alarm calls and communication calls were recorded. The gibbons sang their morning songs mainly in the early morning, with a single bout lasting more than 10 min on average. The singing of a group would trigger other groups, and all groups in an area tended to sing sequentially. The morning duet song bout was dominated by an adult male. The male emitted booms, aa notes, early multimodulated figures, intermediate multimodulated figures and codas, the latter occurring only in duets following the female's great call. The female uttered great calls and abortive great calls. The subadults or juveniles also took part in the morning songs. Lone males were heard to utter solos which lasted longer than the duets of the pairs.

子午岭60年辽东栎林种子质量与森林更新

辽东栎是我国暖温带落叶阔叶林地带的优势乔木树种之一。通过26年的定位监测,对子午岭辽东栎林种子质量消减、种子萌发与环境条件、实生苗时空分布动态以及对其森林更新的影响等方面进行了初步探讨。结果表明:辽东栎林在子午岭半阳坡、半阴坡和阴坡3种类型中,平均完好种子占种子总数的26.65%;霉变种子占18.72%;动物取食虫蛀种子在阴坡远高于半阴坡和半阳坡,占到种子总数的26.32%;已发芽的种子占其总数的28.31%,且半阴坡>半阳坡>阴坡。每年均有大量种子生产,但在生境与动物的共同作用下,种子数量和质量受到很大影响,多达73.35%的种子失去生命力,直接影响实生苗的形成;地表覆盖物虽能促进种子的快速发芽,但对成苗却是一个物理障碍,影响是负作用的,主要影响因子是地表覆盖物的厚度和含水量;在辽东栎林下虽有一定的实生幼苗分布,但数量极少,平均密度仅为140~120株/hm2,且不同立地条件差异显著,严重影响森林的天然更新。

辽西山地乡土树种开发利用的理论基础与技术

辽西山地由于人为破坏严重，自然环境恶劣，建国以来，国家和地方先后投入了大量的人力与物力，开展以人工植被建设为主要目的工程治理。由于诸多方面原因，辽西生态建设多注重理论的探讨和工程的实施，技术开发没引起足够重视。 本文以山地乡土树种开发利用的理论和技术为主要内容，对辽西地区生态建设的理论和方法进行研究，目的是为辽西山地生态恢复与环境治理提供相应的理论基础和技术指导，以期在辽西生态与环境建设中以较少的投资获得较大的生态效益。 本研究有如下工作和结果：(1)分析并明确了辽西山地生态建设主要矛盾，指出辽西山地生态建设应遵循恢复生态学理论；（2）通过对干燥度测算，明确了辽西山地属于半干旱区与半湿润区的交错地带，从而对辽西山地给出了现实的生态区划定位；（3）利用修正的Thornthwaite公式计算了这一地区的最大潜在蒸发量，分析了水分的盈亏状况；（4）研究分析了乡土树种生长与气候因子的关系；（5）在分析现有森林资源的基础上，确认人工植被建设中纯林比重过大、乡土树种比例过小、生态系统十分脆弱；（6）研究了乡土树种资源，结果表明辽西山地乡土树种丰富，可以开发的较多，进而提出了可利用的乡土树种耐旱的形态和生理特征；同时，进一步提出了主要乡土树种研究和开发课题；（7）从生态工程的原理出发，提出并设计了辽西地区利用乡土树种可进行的生态建设工程项目。

长白山阔叶红松林树种的空间分布格局：机会还是竞争？

森林群落中物种是怎样分布的？各物种是如何共存于同一群落中的？物种的分布格局是如何随尺度变化的？哪些过程影响了物种的空间分布格局？森林群落中是否存在着强烈的种内或者种间竞争？是机会还是竞争在构建森林群落中起着更为重要的作用？这些问题的回答，对于我们了解森林群落的结构特征及其内在的生态学过程、揭示物种多样性维持和共存机制具有极其重要的意义。本论文以长白山阔叶红松林25 ha大型固定样地为研究平台，基于第一次样地调查数据，采用不同的空间格局分析方法，从不同的研究角度，对阔叶红松林的群落组成与结构特征、空间格局、种间关系、密度制约机制、物种共有度格局等进行了较详尽的研究。主要研究结论如下： 1) 样地内胸径≥1cm的木本植物共18科32属52种。总的独立个体数为38902，包括分枝的总个体数为59121。个体数最多的前3个种的个体数占总个体数的60%，前14个种占95%，而其余38个种仅占5%。从物种多度、胸高断面积、平均胸径和重要值来看，群落成层现象显著，具有明显的优势种。 2) 对树种空间分布格局的分析发现：树种的空间分布格局随树种、径级、垂直高度、空间尺度的变化表现出不同的分布格局；大多数树种在较小的空间尺度上是聚集的，聚集程度随林层的增高而降低，而在较大的空间尺度则主要表现为规则或者随机分布；小树在小尺度上表现出不同程度的聚集；一些树种的分布格局表现出一定的空间异质性。 3) 对树种的种间相关性分析发现：树种的种间相关性随树种、径级、垂直高度、空间尺度而变化；红松与紫椴在整体上表现为正相关，但并不是在各林层间都表现为正相关；红松和紫椴的幼树和小树大多聚集在母树的周围，蒙古栎和水曲柳的幼树和小树在母树周围分布较少；对不同树种在不同径级和垂直层的空间相关性的分析发现，蒙古栎和水曲柳多分布在光环境比较好的地方，而红松和紫椴这两个耐阴树种则分布在郁闭的冠层下，表明不同的物种具有不同的生境要求以满足其存活和建成的需求；通过比较6个个体数差异极大的槭属树种的种群结构、空间格局和空间相关性等发现，15个物种对中的7个物种对不存在明显的相关性，不同径级的物种对之间的比较也没有发现明显的相关性，即它们之间并不存在明显的种间竞争。 4) 分析密度制约机制对树木存活的影响，可以发现：死亡前树种的格局大多是比死亡后更加聚集的；对于死亡后存活树木的格局，5个主林层树种中的3个和8个次林层和林下层树种中的3个树种的死亡都是随机的，8个次林层和林下层树种中的5个表现出正的密度制约存活；13个树种中的9个树种的存活与其自身的胸高断面积负相关，表明在大树之间存在着强烈的种内或种间竞争；主林层树种存活与近邻距离内同种的个体数没有明显相关性，而次林层和林下层树种的存活与近邻距离内同种的个体数大多呈正相关；大多数树种的存活与同种的胸高断面积表现出负相关，表明了强烈的种内竞争的存在，树木个体的大小对种内竞争的贡献要远远大于该树种种群的密度。 5) 对物种共有度格局的分析发现：阔叶红松林群落在小的空间尺度上出现了较少的物种共有度格局，表明也许存在强烈的种间竞争；而在较大尺度上，基于群落等级、个体数较多的物种组和径级较大的物种组的分析，都出现了随机的物种共有度格局，表明在较大的尺度上并不存在明显地影响物种分布的生态学过程；基于系统发生的物种组的物种共有度格局明显地不同于群落等级的物种共有度格局，在系统发生的物种组内，没有发现种间竞争的证据，而在小尺度上却存在正的种间相关性。 6) 从不同角度对物种分布格局的分析可以看出，森林群落结构与空间尺度是密切相关的。树种的空间分布格局随尺度而变化，在一个尺度上表现为一种格局，而在另一个尺度上则可能表现为另一种不同的格局。种内和种间相关性的分析也在不同的空间尺度上表现出不同的空间相关性。

CO2浓度升高对三个树种资源分配模式的影响

　　由大气CO2浓度升高导致的气候变化是全球变化的重要研究内容之一。大气 CO2浓度升高会对植物的生理活动产生深刻的影响。本论文以开顶箱（Open top chamber）法控制 CO2浓度，在长期野外实地模拟基础上，研究三个树种资源分配模式的变化，揭示了长白山地区三个主要树种—红松（Pinus koraiensis）、长白松（Pinus sylvestriformis）和蒙古栎（Quercus mongolica）叶含碳结构物质和次生代谢物（CBSSCs）含量的变化动态及植物各器官内碳-防卫物质分配模式对CO2浓度升高的响应，这对预测未来CO2浓度升高条件下树木的适应性提供了科学依据。研究结果如下： 1）红松和长白松针叶总非结构性碳水化合物含量在生长季呈现先升高后降低的变化趋势，生长季末期稍有升高，休眠季含量较稳定。脂肪和结构性物质如半纤维素、纤维素和木质素含量在生长季和休眠季中含量比较稳定。 2）CBSSCs在植物叶中的含量存在显著的种间差异性，CBSSCs含量在生长季变化较大，休眠季变化很小。 3）从三个树种叶CBSSCs浓度的年平均值来看，植物对高浓度CO2没有持续和明显的反应，叶内不会出现较高浓度的酚类物质和其它CBSSCs物质。 4）高浓度CO2对植株氮总量没有影响，但由于生长导致的稀释效应使得红松叶、茎全氮浓度显著降低。 5）长期高浓度CO2处理使得红松生长和光合能力都有提高，碳向酚类物质和结构物质的分配提高。由高浓度CO2诱导的植物的这种碳向防卫物质的分配格局符合生长分化平衡模型（GDBe）的预测结果。

CO2浓度升高对三种树木叶片化学和舞毒蛾幼虫取食及生长的影响

探讨全球气候变化的生物学和生态学效应是当今生态学中的热点，研究大气CO2浓度升高对植物-昆虫相互作用关系的影响具有重要的理论和实践意义。本文使用开顶式气室（Open-top chamber，OTC）在野外条件下研究了CO2浓度升高对三种树木（小青杨、白桦和蒙古栎）叶片化学成分含量的影响，以及树木叶片品质变化对一种广食性森林昆虫（舞毒蛾）幼虫取食、生长发育和取食偏嗜性的影响。得出如下结果：（1）CO2浓度升高对3个受试树种叶片中的营养成分及次生代谢物含量均有显著影响，总体表现为氮含量降低，而碳氮比、非结构性碳水化合物、总酚和缩合丹宁含量增加。叶片中的化学成分含量可随时间发生显著变化，不同树种、甚至同一树种不同冠层高度的叶片对CO2浓度升高的响应强度也是不同的。叶片的干物质含量和比叶重对CO2浓度升高的响应不显著。（2）室内非选择性取食实验、室内选择性取食实验以及上树取食饲养方式下的多龄期取食实验，均发现高浓度CO2处理组内舞毒蛾幼虫的生长发育受到显著抑制。但对四龄舞毒蛾幼虫所进行的短期生物测定并未发现不同CO2浓度处理下幼虫的生长发育速率、对食物的取食率和转化率等昆虫营养指标存在显著差异。（3）叶片品质的降低是导致舞毒蛾幼虫生长发育受抑制的主要原因。但是总体上，CO2浓度升高导致的叶片品质变化并未显著影响幼虫的取食率和取食量。（4）舞毒蛾幼虫对不同叶片种类表现出清晰的取食选择性，这种选择性在其幼龄期就可表现出来。幼虫对小青杨上层叶片有最显著的偏嗜性，对蒙古栎下层叶片有最明显的拒食性。但是CO2浓度升高导致的叶片品质变化对舞毒蛾幼虫的取食选择性和寄主偏嗜行为并未产生显著影响。（5）检测出高浓度CO2处理组内舞毒蛾幼虫虫粪中含有浓度更高的植物次生代谢物质（总酚和缩合单宁），这很可能是昆虫整体生长发育受抑制的重要原因之一。

辽东山区次生林生态系统主要树种幼苗对光环境的响应

辽东山区森林是辽宁省重要的水源涵养基地与用材林资源，在维系区域内生态环境和林产品的可持续供应方面占据十分重要的战略位置。该区的天然林已基本绝迹，因此该区的森林生态恢复具有重要意义。 已有研究表明，影响辽东山区森林更新演替最主要的环境因素是光环境。核桃楸（Juglans mandshurica）、水曲柳（Fraxinus mandshurica）、黄菠萝（Phellodendron amurense）和红松(Pinus koraiensis)是阔叶红松林的优势树种；这些树种幼苗对光环境的适应性差异，在群落演替和森林生态恢复中发挥重要作用。 本论文采用人为控制遮光试验测定了核桃楸、水曲柳和黄菠萝幼苗对光环境的响应，同时，采用自然光环境试验和人为控制遮光试验相结合的手段测定了红松幼苗对光环境的适应性。人为控制遮光试验设置的光环境类似于自然中的典型林窗、林缘和林下的光环境；在人为控制遮光试验中，研究材料于2007年4月末栽植于4个不同光环境（全光、全光的60%、30%和15%，分别记为FI、II、LI和WI处理）下，在2007年7~9月测定了树种幼苗的光合生理、叶片特征、生长和冠层形态特征等方面的变化，结果表明： 1）不同光环境处理区内的光合有效辐射（PAR）具有显著差异，形成一定的光强梯度，而气温，相对湿度和土壤含水量差异并不显著。全光处理区内的日平均PAR为842.4μmol∙m-2∙s-1，最大PAR为1884.1μmol∙m-2∙s-1，显著高于其它处理区。 2）生长在高光强下4个树种幼苗的叶片有较高的光合能力（Amax），随生长光强的下降，Amax显著下降；光补偿点（LCP）和光饱和点（LSP）也表现出随着生长光强的下降而降低的趋势。核桃楸和水曲柳净光合速率Pn的日变化最大值约为16μmol∙m-2∙s-1，黄菠萝的约为13μmol∙m-2∙s-1，这与温带阔叶树种叶片的最大净光合速率Pn在10~15μmol∙m-2∙s-1范围内的结论相符；3个苗龄红松针叶的Pn日变化均呈单峰型，没有光合“午休”现象，峰值出现在11:00~13:00期间。 3）4个树种幼苗的比叶重（LMA）和单位叶面积鲜重（LFA）均随着光环境的降低而下降；三个阔叶树种幼苗的叶长L、叶宽W、叶周长C和单叶面积A均具有随着光强的降低而呈增大的趋势，表明叶片通过调节叶片的形态来适应多变的光环境。 4）不同光环境对阔叶树种幼苗的植株冠形和生长有显著影响，而红松幼苗植株冠形和生长的变化无明显的规律性。 综上，本研究得出以下结论：○1.通过可塑性分析和模糊隶属函数分析，核桃楸和黄菠萝较水曲柳能适应更宽的光强幅度；同时，核桃楸和黄菠萝较水曲柳的需光性更强，核桃楸和黄菠萝的需光性差异不大。○2.与3年、5年生红松相比，7年生红松对光强的适应幅度最小；同时，7年生红松的需光性强于3年和5年生红松。○3.本研究结果支持前人的观点：红松在幼年阶段能耐一定程度的遮光，在全光的20%~60%光条件下生长较好，随着年龄的增大，红松的需光性增加。

长白山主要树种对水氮变化的响应特征

探讨全球及区域性降水变化和大气氮沉降增加对植物的影响，能够为预测未来气候变化背景下植物相对竞争能力的变化及陆地生态系统的植被组成及其演替动态提供科学依据。本实验以我国温带典型红松针阔叶混交林主要组成树种紫椴（Tilia amurensis）、水曲柳（Fraxinus mandshurica）、蒙古栎（Quercus mongolica）和红松（Pinus koraiensis）为研究对象，采用控制试验的方法，在自然条件下模拟降水和氮素变化，研究幼树的光合特征、形态、生长及生物量分配对水氮变化的响应。主要结论如下： (1) 降水变化后，紫椴幼树保持自身的光合、形态、生物量及其分配特征不变；氮素添加后，紫椴幼树通过茎部的快速生长来提高对水分和养分的传输能力，植株的生物量也有较大增长。 (2) 在增加30%自然降水时，水曲柳幼树的光合速率降低，但并没有影响到整个生长季的生物量积累的提高；氮素添加后，水曲柳幼树各器官生物量和植株生物量都有增加。 (3) 蒙古栎幼树的光合碳同化能力受水、氮变化的影响不明显。蒙古栎幼树调节各器官的生物量分配，作为应对降水格局变化的策略，即减少30%自然降水时分配给茎部的同化物也减少，增加30%自然降水时茎干生长加速以适应水分传输的要求；氮素添加后，蒙古栎幼树通过增加对叶的同化物的分配，以调节各器官的生物量分配策略。 (4) 红松幼树的光合碳同化能力受水、氮变化的影响不明显。为适应水分的变化，红松幼树在减少30%自然降水时地上生物量减少、增加30%自然降水时地下生物量增加；氮素添加后，红松幼树总体生物量保持增加。 因此，面对全球变化背景下的水、氮变化，水曲柳幼树和红松幼树能更有效地利用增加的降水和氮素，而氮素增加对这两个树种生长的促进作用在降水减少时将被削弱；紫椴幼树的生长更多地受到氮素添加的促进，对降水格局变化响应不明显；蒙古栎幼树则通过调节生物量分配来适应变化的生存环境，但光合特征和植株生物量变化不大。在同龄的针阔叶幼树的竞争中，针叶树种在光合能力和形态特征等方面均占弱势。因此，在比较适应水氮变化的两个树种中，水曲柳幼树的竞争优势更加明显。

沈阳城市森林生态系统健康与管理研究

本文系统研究了沈阳城市森林的布局与结构、城市森林功能、城市森林病虫害发生与树木健康状况和城市自然资源与社会经济状况等指标对沈阳城市森林生态系统健康与管理的影响。同时一，采用2种生态系统健康评价方法对沈阳城市森林生态系统健康状况进行了评价，并提出了沈阳城市森林生态系统健康管理的对策。研究结果如下：1、截至2004年末，沈阳城市森林植被覆盖率已经达到35％，城市森林林地分布基本合理，但需要进一步加强道路林地、居住区林地和城郊大面积生态林建设。2、沈阳城市森林以乔木为主，乔灌株数比为1.7：1，乔灌的覆盖度比约为7:1。3、沈阳城市森林不同类型林地中植物组成不同。公园林地中有74个属，137个种（变种）；庭院林地中有53个属，104个种（变种）；居住区林地中有45个属，81个种（变种）；道路林地中有43个属，94个种（变种）；运河风景林地中有75个属，142个种（变种）；棋盘山风景林地中有48个属，118个种（变种）。4、公园林地、庭院林地、居住区林地、道路林地和运河风景林地的Shannon一Wiener多样性指数分别为2.78、3.05、3.15、3.18和3.18，均匀度指数分别为0.56、0.66、0.72、0.70和0.64。除了棋盘山风景林地外，沈阳城市森林中栽植总量超过乔木总量5％的乔木树种有7个属，分别为李、柳树、杨树、桧柏、榆树、槐树和银杏，7种树木总量达到了全部乔木总量的82.09％；栽植总量超过灌木总量5％的灌木树种也有7个属，分别为水腊、丁香、李属，小聚、玫瑰、忍冬和连翘，7个属灌木总量达到了全部灌木总量的87.92％。5、公园林地、庭院林地、道路林地和防护林地中OBH＜20cm、20cm＜DBH＜60cm和DBH＞60cm树木的比例分别为：57.9％、40.0％、2.1％，49.2％、47.8％、3.0％，65.3％、33.1％、1.6％和64.6％、34.9％、0.5％，表明沈阳城市森林树木的规格总体上偏小。6、经样方调查和CITYgreen模型计算，沈阳城市森林的生态效益约2.0亿USD／yr.。公园林地、庭院林地和风景林地的景观指标相对较高；道路林地和居住区林地的景观效果一般；防护林地的景观效果较差。7、目前已经发现的沈阳城市森林病害约600余种，虫害约700余种，其中杨树主要病虫害39种，柳树的主要病虫害有33种，榆树和槐树的主要病虫害均为，1种。杨柳树腐烂病、光肩星天牛、天幕毛虫、桃红颈天牛和美国白蛾等是近10年来沈阳城市森林中普遍发生和造成严重危害的主要病虫害。沈阳城市森林主要树木的平均健康指数为2.68，处于一般健康状态。8、沈阳城市森林的土壤和水资源状况均不利于树木的健康生长，沈阳的社会经济发展也有待于进一步提高。9、经过生物指示物法（光肩星天牛为生物指示物）、专家权重法、公众问卷调查和对比研究，沈阳城市森林生态系统总体上处于亚健康状态。10、通过对沈阳城市森林资源、管理状况的调查研究和健康状况的评价，本文提出了沈阳城市森林生态系统健康管理的对策，包括合理规划沈阳城市森林林地布局，增加道路林地、居住区林地和城郊林地的面积和植被覆盖率；调整树木种类组成，避免单一或少数树种的大量栽植，提高生物多样性水平；保护大树和古树；增加城市森林管理资金的投入；应用先进技术，采取科学的病虫害防治和植物养护方法，促进树木的健康生长等。This project systematically studied the urban forest ecosystem health and management in Shenyang. The study explored factors, such as urban forest structure, distribution, pests, aesthetic value, ecological benefit, natural resources and socieo-economic status, that affecting the urban forest ecosystem health and management. Two methods were used to evaluate the ecosystem health. This project also proposed Shenyang's urban forest ecosystem health management strategies. The research results can be summarized as follows: 1. As of the end of 2004, urban forest coverage in Shenyang is about 35%, and is in relatively even patch distribution pattern. However, the street trees and roadside forest patches, residential block forest patches should be enhanced. 2. Trees are the major component of the Shenyang s urban forest, followed by shrubs. The quantity ratio of tree to shrub is about 1.7:1, and the coverage ratio of trees to shrub is about 7:1. 3. Species composition varies by location. There are 74 genera, 137 species (including varieties) in the public parks; 53 genera, 104 species (and var.) in the green spaces of the institution (including school), factory, and company; 45 genera, 81 species (var.) in residential blocks; 43 genera, 94 species (var.) in streets and roadside forest patches; 75 genera, 142 species (var.) in the Canal landscape forest patches; 48 genera, 118 species (var.) in the Qipan Mountain recreation forest. 4. The Shannon-Woener indices varies in parks, in institution, factory, and company yards, in streets and roadside forest patches, in residential blocks.there are 2.78, 3.05, 3.18, 3.15, 3.18, respectively; and the evenness indices are 0.56, 0.66, 0.70, 0.72, 0.64, respectively. Besides the Qipan Mountain forest patches, trees of 7 genera, Prunus spp., Salix spp., Populus spp., Sabina spp., Ulmus spp., Robinia spp. and Ginkgo biloba are of more than 5% the total urban trees, respectively. In fact, trees from these 7 genera are about 82% of all trees in Shenyang's urban forests. In terms of shrubs, species of 7 genera, Ligustrum spp., Syringa spp., Prunus spp., Berberis spp., Rosa spp., Lonicera spp., and Forsythia spp. are more than 5% the total urban shrubs, respectively. 88% of all the shrubs in Shenyang s urban forest are from these 7 genera. 5. The diameter class of DBH<20cm, 20cm60cm of trees in parks, in institution, factory, and company yards, in in streets and roadside forests, and in protective forests are 57.9%, 40.0%, 2.1%; 49.2%, 47.8%, 3.0%; 65.3%, 33.1%, 1.6%; and 64.6%, 34.9%, 0.5%, respectively. The result indicated that the DBH is relatively small in Shenyang s urban forests. 6. Using random plots sampling and CITYgreen model calculation, the ecological benefit of Shenyang's urban is about 0.2 billion US dollars per year. The aesthetic value of parks, institution and company yards, and scenary forest patches is relative high; however, the aesthetic value of protective forest patches is low. 7. There are more than 600 types of diseases and more than 700 kinds of insects in Shenyang's urban forest. Among them, Populus spp., Salix spp., Ulmus spp. and Robinia spp., are attached mainly by 39, 33, 11, and 11, difference types of pests respectively. The rot disease of the Populus spp. and Salix spp., and the insects such as, Anoplophora glabripennis, Malacosoma neustria, Aromia bungii, and Hyphantria cunea are major pests in Shenyang s urban forest for the past 10 years. The trees health condition is relatively poor by having the average health index of 2.68 for major species. 8. The urban soil and water resource are not favorable to tree's growth in Shenyang, and so is the socieo-economic status. 9. Through using bio-indicator, professional and public evaluation, and comparision with other urban forests, it can be concluded that the status of Shenyang s urban forest is not very healthy in general. 10. To improve the urban forest ecosystem health in Shenyang, a better urban forest design need to be implemented to enhance the area and vegetation coverage of the street and roadside forests, the residential block forests, and the surburb forest Species biodiversity need to be enhanced by adjust the species composition of urban forest trees to reduce the single or several tree species populations and to plant more varieties. A better fundings for urban forest health management need to be budgeted. Advanced technologies in tree care and scientific measures to control pests need to be adopted to prove better care for plants and to keep trees grow healthfully.

辽西山地乡土树种开发利用的研究

辽西山地由于人为破坏严重，自然环境恶劣，建国以来，国家和地方先后投入了大量的人力与物力，开展以人工植被建设为主要目的工程治理。由于诸多方面原因，辽西生态建设多注重理论的探讨和工程的实施，技术开发没引起足够重视。本文以山地乡土树种开发利用的理论和技术为主要内容，对辽西山地生态建设的理论和方法进行研究，目的是为辽西山地生态恢复与环境治理提供相应的理论基础和技术指导，以期在辽西生态与环境建设中以较少的投资获得较大的生态效益。本研究有如下工作和结果：（1）分析并明确了辽西山地生态建设主要矛盾，指出辽西山地生态建设应遵循恢复生态学理论；（2）通过对干燥度测算，明确了辽西地区属于半干旱区与半湿润区的交错地带，从而对辽西山地给出了现实的生态区划定位；（3）利用修正的Thornthwaite公式计算了这一地区的最大潜在蒸发量，分析了水分的盈亏状况；（4）研究分析了乡土树种生长与气候因子的关系；（5）在分析现有森林资源的基础上，确认人工植被建设中纯林比重过大、乡土树种比例过小、生态系统十分脆弱；（6）研究了乡土树种资源，结果表明辽西山地乡土树种丰富，可以开发的较多，进而提出了可利用的乡土树种耐旱的形态和生理特征；同时，进一步提出了主要乡土树种研究和开发课题；（7）从生态工程的原理出发，提出并设计了辽西地区利用乡土树种可进行的生态建设工程项目。

长白山阔叶红松林主要树种对水分胁迫的生理生态响应

本文系统研究了长白山阔计卜红松林主要树种红松、水曲柳、胡桃揪和锻树在模拟水分胁迫下的生理生态变化。研究表明：（l）土壤水分胁迫对供试树种的生比清况有显：影响。在轻度水分胁迫下（Mw），红松和水曲柳的地下生物量／地上生物量值比对照组（CK）高，而胡桃揪和锻树的地下生物燮／地上生物量比对照组（CK）低。在重度水分胁迫下（LW），供试树种中只有红松的地下生物量／地上生物量比对照组高。（2）土壤水分胁迫对供试树种的生理生态指标有显著影响。在轻度水分胁迫下（Mw），红松和水曲柳的光合速率和水分利用效率比对照组（CK）高，胡桃揪和锻树的光合速率和水分利用效率比对照组（CK）低。在重度水分胁迫下（LW）供试树种的光合速率和水分利用效率都比对照组低。（3）在正常水分条件下（CK），水曲柳光合速率曰变化呈单峰曲线，轻度（Mw）和重度水分胁迫（LW）下均呈"双峰"曲线。正常水分条件下（C）水分利用率的日变化呈双峰曲线，轻度和重度水分胁迫下呈现波动趋势，无明显的波峰和波谷。（4）水曲柳的光合速率和水分利用效率与各因素间多元线性回归的结果表明，三种水分处理下的蒸腾速率、气温、叶温、气孔导度、胞间CO2浓度、光合有效辐射均对光合速率，水分利用效率有一定影响，但影响程度有所差别。（5）土壤水分胁迫对水曲柳、胡桃揪和锻树的初始荧光（Fo）、可变荧光（Fv）、最大荧光（Fm）的影响不大，但却显著影响各树种的PSII原初光能转换效率（Fv／Fm）和PSII潜在活性（Fv/Fo）。（6）土壤水分胁迫影响供试树种几！中的养分含量，但影响程度是不同的，水分胁迫对磷、钾素含量的影响比对氮的大。土壤水分亏缺对各树种叶中的Ca元素无显著影响。红松、胡桃揪和极树叶片中的Mg含量随着土壤水分胁迫的加重也随之逐渐减小，但水曲柳在轻度水分胁迫下叶中的Mg含量最高，关于这一现象还有待以后开展深入的研究。

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.

CO2浓度升高对红桦幼苗生理与生长的影响

大气CO2浓度的增加已经成为不可争议的事实。预计本世纪末大气CO2浓度将增加到约700µmol mol-1。森林年光合产量约占陆地生态系统年光合产量的70%。森林树木是一个巨大的生物碳库，约占全球陆地生物碳库的85%。森林树木对CO2的固定潜力是缓解由大气CO2浓度升高引起的未来全球气候变化问题的决定性因子之一。红桦（Betula albosinensis Burk.）是川西亚高山采伐迹地自然或人工恢复的重要树种。本研究以1a红桦幼苗为模式植物，采用人工模拟的方法，研究CO2浓度升高对不同种内竞争强度（种群水平）下红桦幼苗的生理特征、生长、干物质积累及其分配的影响，探讨在种内竞争生长条件下红桦幼苗的“光合适应机理”与生长特征，为西南亚高山森林生产力对未来全球变化的预测提供重要参考。 本研究的主要结果如下： 1）在种内竞争生长条件下红桦幼苗经过CO2浓度升高熏蒸4个月后，叶片出现“光合适应”现象。与对照相比，低种植密度（28株m-2）和高种植密度（84株m-2）条件下的红桦幼苗净光合速率（A）、气孔导度（gs）、蒸腾速率（E）、表观量子产量（AQY）和羧化速率（CE）显著降低，而水分利用效率（WUE）则显著提高。CO2浓度升高处理的红桦幼苗叶片Rubisco活性、单位叶面积N浓度、叶绿素a、叶绿素b和类胡萝卜素浓度都显著降低。但CO2浓度对红桦幼苗的叶绿素a与叶绿素b的比值没有显著影响。CO2浓度升高显著增加红桦幼苗单位叶面积的非结构性碳水化合物（TNC）浓度，结果是红桦幼苗的比叶面积（SLA，cm2 g-1）显著降低。 2）与对照相比，CO2浓度升高处理的红桦幼苗高、基径、单叶面积和侧枝的相对生长速率（R GR）显著提高，尤其在试验处理的早期。CO2浓度升高既增加单株红桦幼苗总叶片数量又增加单叶面积，结果是单株红桦幼苗的总叶面积比对照显著增加。 3）CO2浓度升高处理显著增加红桦幼苗干物质积累（尤其是细根生物量），改变了红桦幼苗生物量的分配格局。与对照相比，CO2浓度升高处理的红桦幼苗叶重比（LWR）、叶面积比（LAR）、叶根重比（Wl/Wr）和源汇重比（leaf weight to non-leaf weight ratio, Wsource/Wsink）显著下降（高种植密度的LWR除外），而根冠比（R/S）则显著增加。在两种种植密度条件下，CO2浓度升高显著增加红桦幼苗根生物量的分配比率，显著降低叶片的生物量分配比率，对主茎、侧枝以及地上生物量的分配比率不变或约有下降。 总之，长期生长在CO2浓度升高条件下的红桦幼苗光合能力下降，并伴随Rubisco活性、叶N浓度、光合色素浓度的显著降低以及TNC浓度的显著增加。支持树木光合速率下降与Rubisco活性、叶N浓度下降以及TNC浓度增加紧密相关的假设。CO2浓度升高处理红桦幼苗的早期相对生长速率大大高于对照，而后期迅速下降，说明红桦幼苗生物量的显著增加主要归功于CO2浓度升高的早期促进作用和叶面积的显著增加。CO2浓度升高显著增加红桦幼苗根系生物量和根冠比，表明红桦幼苗“额外”固定的C向根系转移。 The steady increae of atmospheric CO2 concentration（[CO2]）has been inevitable fact. Models predict that the atmospheric [CO2] will increase to about 700µmol mol-1 at the end of the twenty-first century. As trees constitute a majoor carbon reservoir–85% of total plant carbon is found in forest, and their ability to sequester carbon is a key determinant of future global change problems caused by increases in atmospheric CO2. In addition to the role of forests in the global carbon cycle, inceased growth could be of economic benefit, for example, offsetting deleterious effects of climatic changes. Betula albosinensis (Burk.) usually emerges as the pioneer species in initial stage and as constructive species in later stages of forest community succession of mountain forest area, and also is one of important tree species for afforestation in logged area, in southwesten China. In this experinment, Betula albosinensis seedling (one-year-old) was used as the model plant. B. albosinensis seedlings were grown under two all-day [CO2], ambient (about 350 µmol·mol-1) and elevated [CO2] (about 700 µmol·mol-1), and two planting densities of 28 plants per m2 and 84 plants per m2. The objectives were to characterize birch mature leaf photosynthesis, growth, mass accumulation and allocation responses to long-tern elevated growth [CO2] under the influences of neighbouring plants, and to assess whether elevated [CO2] regulated birch mature leaf photosynthetic capacity, in terms of leaf nitrogen concentration (leaf [N]), activity of ribulose bisphosphate carboxygenase (Rubisco), Rubisco photosynthetic efficiency, and total nonstructural carbohydrates (TNC) concentration, and also to provide a strong reference to predict the productivity of subalpine forests under the future global changes. The results are as follows: 1) B.albosinensis seedlings exposed to elevated [CO2] for 120 days, photosynthetic acclimation phenomena occurred. At two planting densities, leaves of birch seedlings grown under elevated [CO2] had lower net photosynthetic rate (A), stomatal conductance (gs), transpiration (E), apparent quantum yield (AQY) and carboxylated efficiency (CE) and higher water use efficiency (WUE), compared to those of B.albosinensis seedlings grown under ambient [CO2]. Based on the leaf area, leaf [N], Rubisco activity and photosynthetic pigments concentrations of B. albosinensis seedlings grown under elevated [CO2] were significantly lower than those grown under ambient [CO2]. The ratio of chlorophyll a to chlorophyll b concentration was not affected by elevated [CO2]. Under elevated [CO2], the TNC concentration per unit leaf area significantly increased, resulting in significant decrease in specific leaf area. Thus leaf photosynthetic capacity of B. albosinensis seedlings would perform worse under rising atmospheric [CO2] and the influences of neighbouring plants. 2) Under elevated [CO2], the relative growth rate (RGR) of B. albosinensis seedlings height, basal diameter, a leaf area and branch length significantly increased, especially at the initial stage of exposure to elevated [CO2], and a leaf area and leaf numbers per B. albosinensis seedling also significantly increased. Thus the total leaf area per B. albosinensis seedling was significantly increased under elevated [CO2]. 3) As the increase of RGR and total leaf area, biomass of B. albosinensis seedling grown elevated [CO2] was higher, compared to that of B.albosinensis seedlings grown at ambient [CO2]. Elevated [CO2] changed the biomass allocation pattern of B. albosinensis seedling. At two planting densities, B. albosinensis seedlings grown elevated [CO2] had lower leaf weight to total weight ratio (LWR), leaf area to total weight ratio (LAR) and leaf weight to non-leaf weight ratio (Wsource/Wsink), but higher root weight to shoot weight ratio (R/S), compared to those of B.albosinensis seedlings grown at ambient [CO2]. Under elevated [CO2], roots biomass to total biomass ratio was signigicantly increased, leaves biomass to total biomass ratio was significantly decreased. The main stem and branch biomass to total biomass ratio were not affected by elevated [CO2]. In conclusion, our results supported the hypothesis that the decline in photosynthetic capacity of C3 plants will appear after long-term exposure to elevated [CO2], accompanying with the significant decrease in Rubisco activity, leaf N concentration, photosynthetic pigments concentration, and significant increase in total non-structural carbohydrates concentration. Our results also have shown that the increase of biomass of B. albosinensis seedlings should be attributed to initial stimulation on RGR and total leaf area resulted from elevated [CO2]. Under elevated [CO2], the extra carbon sequestered by B.albosinensis seedlings transferred into under-ground part because of increase in root biomass and R/S.

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.

岷江上游高山林线附近优势树种土壤种子库和幼苗更新特征的研究

岷江上游地区高山/亚高山植被分布的坡向性分异显著，阴阳坡高山林线不仅物种组成差异明显，并且分布海拔呈现出阴坡高阳坡低的格局．阳坡林线树种主要是圆柏属乔木，林线类型多为渐变型，海拔高度大约在3 400m~3 800m；阴坡林线树种主要是冷杉，林线类型多为骤变型，海拔高度约在3 800m~4 400m．本研究采用土壤种子库物理筛选、室内萌发实验及野外群落调查等方法，对岷江上游地区阴坡岷江冷杉和阳坡祁连圆柏两类林线树种不同海拔梯度上土壤种子库以及幼苗库特征进行了调查，从土壤种子库和幼苗更新特征的角度对林线乔木树种种群更新特征进行了分析，进而对该地区高山林线在阴阳坡分布差异的原因进行了探讨，结果显示： 1．土壤种子库 阴坡：阴坡高山林线附近岷江冷杉土壤种子的平均密度大约为50.96粒/m2，其中树线以上10m处土壤种子密度为1.00粒/m2，树线处大约19.33粒/m2，林线交错带内土壤种子密度最高为136.83粒/m2，郁闭林内种子密度小于林线交错带，只有30.50粒/m2，种子平均空壳率为52％，霉变率达34%，完好种子只有6%．土壤种子库垂直分布特征为地被物层含种子比重最大，大约在67.50%左右；其次为0~2cm层，约18.84%左右；2~5cm层所占种子比例最小，约13.66%左右．霉变种子数量与土壤深度呈负相关． 阳坡：阳坡祁连圆柏土壤种子的平均密度为60.16粒/m2．树线以上10m处密度为1.92粒/m2，树线位置大约108.16粒/m2，林线交错带内平均为75.80粒/m2，郁闭林内种子密度小于林线交错带，只有20.00粒/m2．种子平均空壳率为36％，完好种子占49%，霉变率较低，大约为10%．阴阳坡林线树种土壤种子库垂直分布特征为：地被物层含种子最多，其次为0~4cm层，4~10cm层所占种子比例最小，霉变种子数量与土壤深度也呈负相关． 2． 幼苗库调查 阳坡：在树线以上区域没有发现幼苗，林线交错带内幼苗密度平均达3 250株/hm2，郁闭林内仅2 750株/ hm2．整个样地内1～2a幼苗很少甚至没有出现，3～10a的幼苗相对较多．空间分布上，祁连圆柏幼苗在林线交错带内接近随机分布，郁闭林内则介于随机分布和均匀分布之间． 阴坡：在树线以上幼苗密度为1 250株/ hm2，全部为1~2a幼苗，林线交错带内幼苗密度平均达7 000株/ hm2，郁闭林内达6 250株/ hm2．林线附近岷江冷杉幼苗丰富度以及幼苗的出现频率明显高于祁连圆柏，年龄结构也较祁连圆柏完整．岷江冷杉幼苗空间分布除了树线处幼苗的分布为随机分布，其他海拔则为集群分布． 3．从不同土壤深度的种子总量和幼苗数量的相关性检验发现，当年生幼苗数量跟表层种子总量相关性极显著, 但是两年生幼苗的数量与底层种子数量相关性显著．土壤种子在土壤中的垂直分布格局从一定程度上可以反映种子库的年际特征．岷江冷杉土壤种子库较丰富，种子散布后的存活力随着时间的变化逐渐下降，属于季节性瞬时种子库；祁连圆柏土壤种子散布格局为集群型分布，成熟种子大部分散布在母株冠幅内，属于永久性土壤种子库． 4．在阴坡林线交错带及以上区域还存在较为丰富的乔木土壤种子，并且在树线以上区域还发现了少量的岷江冷杉幼苗．从样地乔木的年龄结构发现，在林线交错带内上部到树线位置主要以幼龄林为主，且年龄结构完整，基本符合入侵性林线特征；阳坡林线交错带内幼苗出现频率很低，树线以上区域虽然存在种子库，但是没有幼苗出现，在林线交错带内乔木径级差距很大，年龄结构异常不完整，这种特征的林线将会面临两个可能结果：一种是维持现有状态，保持平衡；另外一种就是退化，但阳坡林线的实际动态趋势还有待长期定点研究． Treelines on the upper region of Minjiang River differ between the north aspect and the south aspect in their appearances, altitudes and tree species. On the north aspect, trees of Abies form a sharp and abrupt treeline ranging from 3800m to 4400m, while on the south the treeline is generally lower(3 400~3 800m), more open and gradual and mostly composed of Sabina. In this study, we examined the altitudinal gradients of soil seed banks and seedling recruitments at the treeline ecotones of a N-aspect and a S-aspect by using soil sieving, germination experiment and field investigations, analyzed the characteristics of population regeneration of tree species at the transitional zone and presented a analysis of the causes to the aspect-related difference in treeline patterns in the study area. Major results of our study include: 1． Soil seed bank N-aspect: Of the 50 plots investigated, the average density of soil seeds is 50.96/m2, in which well-formed seeds account for 6%, empty seeds 52%, parasitized seeds34%, and seeds damaged by animals 8%. The size of soil seed bank varies along altitude, being 1.00 seeds /m2 at the 10m above the treeline and ca.19.33 seeds/m2 at the upper limit of treeline. The highest density (136.83 seeds/m2) occurs at the treeline ecotone. By contrast, the density of soil seed for the closed forest is only 30.50 seeds/m2. In terms of vertical strata, 67.50% of the total seeds are at the surface layer, 18.84% at the middle layer (0~2cm) and 13.66% at deeper layer (2~5cm). The number of parasitized seeds is negatively correlated to soil depth. S-aspect: Of the 50 plots investigated, the average density of soil seeds is 60.16 seeds/m2, and the well-formed seeds account for 49%, empty seeds 36%, parasitized seeds10%, and seeds damaged by animals 1%. The size of soil seed bank varies along altitude, with 1.92 seeds/m2 recorded at the10m above the treeline，108.16 seeds/m2 at the upper limit of treeline, and 75.80 seeds/m2 at the treeline ecotone, while that for the closed forest is 20.00 seeds/m2. The number of seeds decreases with the depth of soil. As is on the N-aspect, the size of soil bank, from large to small, follows the order of the surface layer, the middle layer (0~4cm) and the bottom layer (4~10cm). The number of parasitized seeds is also negatively correlated to the depth of the soil. 2． Seedling bank N-aspect: A mean maximum seedling abundance of 31 000 seedlings/hm2 was recorded near alpine treeline at growing season. The density of seedlings is 1 250 seedlings/ha (all being 1 or 2 years old) at the alpine meadow 10m away above treeline, 7 000 seedlings/ha at treeline ecotone and 6 250 seedlings/ha for closed forest．The spatial distribution of Abies faxoniana seedlings is random at the upper limit of the treeline but clumped at other altitudes． S-aspect: No seedlings were found at the alpine meadow 10m away from the treeline. The density of seedlings was 3 250 seedlings/ha at treeline ecotone and 2 750 seedlings/ha for the closed forest．Hardly any 1 year current and 2 year-old seedlings appeared at the plots. The spatial distribution of Sabina przewalskii seedlings is random at treeline ecotone and between “random” and “even” forest closed forest． 3．Correlation tests of seedling population and seed bank at different soil layers indicated that the emergents were strongly correlated to seed bank at surface layer while the number of two-year seedlings was significantly correlated to the seed bank at the bottom of soil layer, indicating that germination mainly occurs at the soil surface while the middle or bottom layer was the reserve for non-germination or dead seeds. It can thus be postulated that Abies faxoniana soil seed bank is of seasonal transient type. By contrast, the soil seed bank of Sabina przewalskii is of persistent type and the soil seeds and seedlings of this species occurred more frequently near the islands of adult trees. 4．A good many soil seeds of both tree species were found near the treeline ecotone and above at N- and S-aspects. A few young seedlings were found above the Abies treeline. Investigation of five altitudinal transects respectively on N- and S-aspects indicated that Abies faxoniana has a more complete age structure than the stands of Sabina przewalskii. The age of firs decreased from closed forest to the upper limit of treeline, which suggests that the Abies treeline is advancing to higher altitude. While on the south aspect, only few Sabina przewalskii soil seeds and nearly no seedlings were found above the treeline ecotone. The stands exhibit extremely great difference in diameter classes with significantly incomplete age structure. This would lead to two possible results for the treelines: maintaining an equilibrium state at the current position or degenerating. But more studies should be carried out at longer time scales or larger spatial scales to understand whether the Sabina treeline is degenerating.