| 题名 | 川滇高山栎萌生更新生理生态特性及其与环境因子的关系 |
| 作者 | 谢静 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 朱万泽 |
| 关键词 | 川滇高山栎 萌生 营养元素 WUE δ13C 光合生理 |
| 其他题名 | Ecophysiological characteristics of sprouts in Quercus aquifolioides and their relationship with environmental factors |
| 学位专业 | 自然地理学 |
| 中文摘要 | 由栎属高山栎类植物组成的硬叶常绿阔叶林是中国植被一个很特殊的类型，广泛分布于横断山区，是横断山区主要森林生态系统类型之一。组成硬叶常绿阔叶林的高山栎类植物中，以川滇高山栎（Quercus aquifolioides）分布范围最广、分布面积最大、分布海拔最高（可达4600 m），大多分布于横断山区高山峡谷地区的阳坡和半阳坡，常常形成这些地区的顶级群落（climax）。川滇高山栎具有较强的萌生更新能力，萌生更新是其遭受火灾、砍伐等干扰后生殖对策转换的一种重要适应，是川西、滇西北地区川滇高山栎灌丛的主要更新方式。本文以川西折多山东坡川滇高山栎为研究对象，通过人工干扰试验，从海拔和年龄两个维度探讨了川滇高山栎萌株营养元素含量、光合生理特性、水分利用效率及其影响因子，主要结论如下： 1. 川滇高山栎萌株营养元素含量（g?kg-1）大小排序为：Ca（9.76）>N（7.71）> K（5.39）>Mg（1.31）>P（1.29），不同器官营养元素含量分配差异较大。从不同年龄来看，川滇高山栎萌株营养元素含量中，N、P、K、Mg在各器官内的含量几乎都表现为4年生萌株低于40年生萌株，仅Ca含量相反。从不同海拔来看，川滇高山栎萌株营养元素含量中，N、P、K、Mg含量在各器官内均表现为3100 m萌株高于3900 m萌株，Ca含量除多年生叶、多年生枝、粗根以外，表现出与其它营养元素相反的趋势。川滇高山栎萌株对各营养元素的生物吸收系数为Ca>N>P> K>Mg，表明对Ca元素的集累能力最强。从不同年龄看，4年生萌株对N、K、Ca的生物吸收系数均远大于40年生萌株，表明树龄越小，川滇高山栎萌株对营养元素的吸收和集累能力更强；从不同海拔看，低海拔萌株对各元素的生物吸收系数几乎都大于高海拔萌株，表明低海拔地区萌株比高海拔地区对营养元素的吸收和集累能力更强。 2. 川滇高山栎萌株叶片Pn日变化呈双峰型，有明显的光合“午休”现象。不同海拔川滇高山栎萌株的Pn和Tr日变化均表现为双峰型，且低海拔萌株的Pn和Tr高于高海拔萌株，Gs和Ci表现出相反的趋势，低海拔地区萌株低于高海拔地区。从不同年龄川滇高山栎萌株的光合生理因子日变化来看，1年生萌株叶片的Pn、Tr、Ci均比40年生萌株大；Gs表现为上午40年生萌株高于1年生萌株，而下午则相反，为40年生萌株低于1年生萌株。根据川滇高山栎光合作用光响应曲线数学模型计算结果所知，随着海拔的升高，川滇高山栎叶片的LSP、LCP、Rd及Pmax均有所增加，AQY有所降低，表明随着海拔的升高，川滇高山栎叶片对强光的适应能力有所增强，对弱光的利用能力也有所增加，叶片光合潜力也随海拔增强。随着川滇高山栎萌株树龄的增加，LSP、LCP、Rd及Pmax均有所增加，AQY有所降低，幼树较高的表观量子效率和较低的光补偿点能使植物在弱光条件下也能进行光合作用，同时较高的量子同化效率和较低的暗呼吸速率使植物呼吸消耗量较低，这对川滇高山栎幼龄萌株的生长有积极作用。根据川滇高山栎光合作用CO2响应曲线数学模型计算结果所知，随着海拔的增高，川滇高山栎萌株叶片Vcmax、Jmax、VTPU均有所增加，Rp和CCP有所降低；随着年龄的增加，川滇高山栎萌株叶片Vcmax、Jmax、VTPU、Rp和CCP均有所增加。 3. 所采集的折多山东坡川滇高山栎萌株的叶片δ13C值分布范围为-28.76‰～-25.51‰。不同海拔的川滇高山栎叶片δ13C之间也存在显著性差异（P<0.05），高海拔地区的川滇高山栎叶片δ13C明显高于低海拔地区。海拔上升1000m，川滇高山栎叶片δ13C增加约1.2‰。表明不同海拔的川滇高山栎萌株长期水分利用效率存在差异，低海拔萌株WUEL低于高海拔。不同树龄的川滇高山栎叶片δ13C之间也存在显著性差异（P<0.05），40年生的川滇高山栎叶片δ13C值明显高于4年生叶片，表明4年生萌株WUEL低于40年生萌株。不同海拔川滇高山栎萌株的WUEi均表现为上午大于下午，且高海拔地区萌株的WUEi大于低海拔地区，和WUEL表现出相同的趋势。同时，川滇高山栎萌株年龄不同，WUEi的大小也有所差异，40年生萌株叶片WUEi最高，5年生萌株其次，1年生萌株最低。 4. 通过对川滇高山栎萌株营养元素含量、光合生理因子、水分利用效率与环境因子之间的相关性分析发现，萌株营养元素含量与土壤营养元素含量及含水量之间相关性明显；光合生理因子中，Pn和Tr与环境因子之间的相关性较弱；Gs与温度有显著的负相关关系，与湿度有极显著的正相关关系；Ci与环境因子之间均达到了显著相关性，与温度、PAR之间为显著的负相关关系，与湿度和CO2浓度之间为显著的正相关关系；叶片δ13C与土壤有机质之间存在显著负相关，与K、Mg含量之间存在显著正相关；WUEi与温度均呈显著的负相关关系，与空气湿度均呈显著的正相关关系。 |
| 英文摘要 | Quercus aquifolioides occupies a wide range of habitats and altitudes from 2000 to 4500m a.s.l., and is a dominant, late-successional and cliamax species of the sclerophyllous evergreen broad-leaved forests on sunny, south-facing slopes in the Hengduan Mountains region, southwest China. Those forests often suffer from firewood, livestock, fire and other disturbances. Quercus species are thought to have less opportunity for seedling establishment, and resprouting is the main regeneration method for most Quercus species after disturbance. We carried out a coppicing experiment with Quercus aquifolioides shrubs of different ages on the southeast-facing slope of Zheduo mountain along an elevational gradient to study the nutrient elements content, physiological characteristics of photosynthesis and water use efficiency. The main results are as follows. 1. The nutrient element patterns of Quercus aquifolioides are Ca > N > K > Mg > P, and the nutrient concentration differed somewhat according to organs. N, P, K, Mg contents in almost all organs of Quercus aquifolioides of 4 years are less than that of 40 years, but on the contrary, Ca contents in the Quercus aquifolioides of 4 years are more than that of 4 years. On the other hand, N, P, K, Mg contents in almost all organs of Quercus aquifolioides of 3100m a.s.l. are more than that of 3900m a.s.l., but Ca contents in the Quercus aquifolioides of 3100m a.s.l. are less than that of 3900m a.s.l.. The biological absorption coefficients of the nutrient elements by Quercus aquifolioides follow the order Ca>N>P>K>Mg. This result indicates that the enrichment capacity of Ca by Quercus aquifolioides is higher than other nutrient elements. The biological absorption coefficients of N, K, Ca by Quercus aquifolioides of 4 years are much higher than that of 40 years, and The biological absorption coefficients of N, P, K, Ca, Mg by Quercus aquifolioides of 3100 a.s.l. are higher than that of 3900m a.s.l.. 2. The diurnal change of net photosynthestic rate(Pn) present a bimodal pattern, i.e., reached the maximun at 10:00 and 14:00, and had a midday depression. The diurnal variation patterns of leaf transpiration rate(Tr) are also bimodal. The Pn and Tr of sprouts are increasing with the increasing elevation. The stomatal conductance(Gs) and the Intercellular CO2 concentration(Ci) are on the contrary. The Pn, Tr and Ci of sprouts are increasing with the increasing age. The Gs of sprouts in the morning are increasing with increasing age, but decreasing with increasing age in the afternoon. According to the mathematical model of light response curves of Quercus aquifolioides, LSP, LCP, Rd and Pmax of leaves increase with the increasing elevations while AQY decreases, suggesting that the leaves of Quercus aquifolioides adapt to both high light and low light condition. LSR, LCP, Rd and Pmax of leaves increase with ages while AQY decreases. High AQY and low LCP of saplings enable themselves totake low light condition for photosynthesis, meanwhile, high AQY and low Rd make respiration comsumption low, and this is benificial for growth. According to the mathematical model of CO2 response curves of Quercus aquifolioides, with the elevations increasing, the Vcmax, Jmax and VTPU of Quercus aquifolioides leaves are increasing, while the Rp and CCP are on the contrary. On the other hand, with the ages increasing, the Vcmax, Jmax, VTPU, Rp and CCP are all increasing. 3. The δ13C of Quercus aquifolioides range from -28.76‰ to -25.51‰. There is a considerable difference in the leaf δ13C of Quercus aquifolioides of different elevations(P<0.05), and when the elevation increases 1000m, δ13C increases 1.2‰, indicating the long-term water use efficiency of trees at lower elevations is lower than that of higher elevations. There is a considerable difference in the leaf δ13C of Quercus aquifolioides of different ages(P<0.05), and the leaf δ13C of 40-year Quercus aquifolioides is higher than that of 4-year, indicating the the long-term water use efficiency of saplings is lower than that of mature trees. The WUEi of Quercus aquifolioides in the morning is higher than that in the afternoon, and the WUEi of Quercus aquifolioides at higher elevations is higher than that at lower elevation, the same with δ13C. On the other hand, there is a difference in the WUEi of Quercus aquifolioides at different ages, and the WUEi of Quercus aquifolioides of 40-year is higher than that of 5-year and 1-year. 4. The relationships between the nutrient element contents, physiological characteristics of photosynthesis, water use efficiency and the encironmental factors are analyzed. The results indicate that there is a correlation between the nutrient element content of and the nutrient , water content of soil. The correlation between Pn, Tr and the environmental factors are weak, but there is a negative correlation between Gs and temperature, and a positive correlation between Gs and humidity. There is a negative correlation between Ci and temperature and PAR, and a positive correlation between Ci and humidity and CO2 concentrition. There is a negative correlation between δ13C and soil organic matter, and a positive correlation between K, Mg content of soil. There is a negative correlation between WUEi and temperature, and a positive correlation between WUEi and humidity. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/17572]  |
| 专题 | 成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室 |
| 作者单位 | 中国科学院成都山地灾害与环境研究所 |
| 推荐引用方式 GB/T 7714 | 谢静. 川滇高山栎萌生更新生理生态特性及其与环境因子的关系[D]. 北京. 中国科学院研究生院. 2015. |
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