黄土丘陵半干旱区典型人工林蒸腾耗水动态研究
文献类型：学位论文
| 学位类别 | 硕士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 陕西 |
| 导师 | 陈云明 |
| 学位专业 | 生态学 |
| 中文摘要 | 本研究利用热扩散技术在黄土丘陵半干旱区安塞县，对刺槐（Robinia pseucdoacacia）和侧柏（Platycladus orientalis）树干液流速率进行了连续的测量（2008年4月25日-10月28日）。结合树干直径，边材面积等指标，构建了相应的模型及参数，实现尺度的扩展。对于探明这2种林分的蒸腾耗水规律，水土保持林区水分管理、林地水文效益分析等具有重要参考价值。通过对刺槐，侧柏典型样木蒸腾耗水与环境因子的关系研究，取得了如下结论。一．人工刺槐树干液流速率动态及耗水规律1.刺槐在展叶期分为四个时期：芽期、展叶初期、中期和全叶期。在芽期，刺槐树干液流速率低，无明显昼夜变化；在展叶初期以后表现出明显的昼夜波动状态，且树干液流速率日变化均成单峰曲线。表现为从微弱波动逐渐增大到趋于平稳波动的总趋势，呈现上升快、下降缓慢的单峰曲线。其峰值在展叶初期与光合有效辐射最大值之间存在一定时滞效应。在展叶中期以后，刺槐树干液流峰值早于各气象参数最大值1-2h出现。刺槐在盛期树干液流速率的日变化呈宽峰形曲线，既树干液流速率达到峰值后并不是不再变动，而是有较小幅度的“波动”，形成多个小峰组成的“高峰平台”，然后才开始下降，没有明显的树干液流静止状态的界限，每日7:00-8:00左右启动，11:00左右达到最大值，21:00左右迅速降到最低值。刺槐在落叶初期呈单峰形曲线，由落叶期开始的昼夜变化峰值逐渐减小在随着叶片的逐渐脱落和自身的物候节律至10月下旬树干液流达到无绪状态，且峰值明显小于盛期的树干液流速率。2.多元线性回归表明：刺槐在展叶后期的全叶期树干液流速率与光合有效辐射、大气温度、水汽压差和风速呈极显著正相关，与相对湿度呈负相关。可用光合有效辐射、大气温度和树干液流速率线性表达式来估算刺槐展叶期的全叶期树木液流速率。在盛期，刺槐树干液流速率与光合有效辐射、大气温度、水汽压差呈极显著正相关，与相对湿度呈负相关。可用光合有效辐射、大气温度和树干液流速率线性表达式来估算刺槐盛期树木液流速率。3.刺槐边材面积与胸径之间存在着高度相关的关系。刺槐日耗水量随直径的增大而增大，即大径阶树木边材较大，相应耗水量也较多。二．人工侧柏树干液流速率动态及耗水规律1.侧柏树干液流速率在不同季节的日变化均为典型的单峰曲线，春、夏季每日从8:00左右启动，10:00左右达到最大值，秋季树干液流启动时间较春、夏季延迟至11:00点左右启动，13:00-14:00左右达到最大值。但从树干液流迅速下降时间来看，春季最晚，在20:00左右迅速下降；秋季最早，为18:00；夏季为19:00。2.多元线性回归表明:侧柏在4-5月树干液流速率与光合有效辐射、水汽压差、大气温度和相对湿度呈极显著的线性相关关系，相关程度顺序为光合有效辐射＞水汽压差＞大气温度＞相对湿度。可用这几项气象因子的简单表达式来估测侧柏树木液流。3.侧柏边材面积和地径间呈良好的幂指数关系。并计算出侧柏人工林的单位边材面积为116.18 m2.hm-2 。通过样木各月的平均流速得出4-10月各月的单位林分耗水量，最终计算出被测侧柏人工林在4-10月的总耗水量为1159.64 t.hm-2 。三．刺槐、侧柏树干液流速率对比分析1.在抽芽展叶时期，侧柏树干液流速率高于刺槐。在生长盛期，刺槐树干液流速率峰值高出侧柏树干液流速率峰值。在10初期刺槐树干液流峰值高出侧柏树干液流峰值，在10月中期，刺槐树干液流峰值小于侧柏树干液流峰值，在10月15-16日以后由于叶片的脱落刺槐树干液流变得紊乱。2.刺槐和侧柏单木日耗水量在整个生长季与其树干液流速率变化规律相一致，即刺槐从生长初期经过生长盛期至生长末期，单株耗水量从展叶初期的较低值随着叶片的扩展逐渐增大到生长盛期达到最大，之后随之降低；侧柏耗水量是逐渐降低。 |
| 英文摘要 | In this study, the thermal dissipation probe (TDP) was used to measure the sap flow velocity of Robinia pseucdoacacia and P.orientalis in Ansai County on the Loess Plateau of China（2008.4.25-2008.10.28）. Combining the sap flow velocity with such indicators like trunk diameter and sapwood area, relative model was built and the expansion of the scale was achieved. Study the law of transpiration water consumption of those two forest types has important reference value to the water management of soil and water conservation forests as well as to the analysis of forest hydrologic effect. After the study of the relationship between transpiration water consumption and the environmental factors of those two typical kinds of local trees (Robinia pseudoacacia, p.orientalis), major conclusions got were as follows: I.Sap flow dynamics and water consumption regularity of artificial Robinia pseucdoacaci 1. The leaf-flushing period of a Robinia pseudoacacia plantation were divided into four periods: germinating stage, the beginning period of leaf-flushing, the middle period of leaf-flushing and the full-leaf period of leaf-flushing. At germinating stage, the Sap flow velocity of R. pseudoacacia was low and there was no obvious diurnal variation. After the beginning period of leaf-flushing, diurnal variation was obvious and the diurnal variation of sap flow velocity displayed a fast-rising and slow-declining single-peak curve, the general trend was from weak fluctuation gradually increased to stable fluctuation. At the beginning period of leaf-flushing, there existed a certain time lag between the peak value of sap flow and that of photosynthetic active radiation. Since the middle period of leaf-flushing, Sap flow peak of Robinia pseucdoacaci appeared as early as 1-2 h before the maximum value of the meteorological parameters. The diurnal variation of sap flow displayed a wide-peaked curve during rapid growth season. That is, the sap flow velocity of Robinia pseudoacacia didn’t stop after reaching its peak, but there were minor fluctuations, a number of small peaks formed a "peak platform", and then began to decline. There were no clear boundaries of static states. It started around 7:00-8:00 every day, reached the maximum at 11:00 and around 21:00 it decreased rapidly to a minimum value. In the early period of defoliation, Sap flow of artificial Robinia pseucdoacaci was single peak-peak curve, and beginning from the defoliation period, the diurnal variation decreases gradually as the leaves fall off. In late October, sap flow started to be in disorder and the peak value was obviously less than that of the growing period. 2. Linear regression indicates that sap flow velocity was outstanding positive correlated with PAR, air temperature, VPD and wind speed, and was negatively correlated with air relative humidity during the full-leaf period of leaf-flushing. Linear representations of PAR, air temperature and sap flow velocity could be used to estimate the sap flow velocity of Robinia pseucdoacacia during its full-leaf period. In growing season, sap flow velocity was significantly correlated with PAR, air temperature and VPD, and was negatively correlated with air relative humidity during the monitoring period, and linear representations of PAR, air temperature and sap flow velocity could be used to estimate the sap flow velocity of Robinia pseucdoacacia during its growing season. 3. There exist significant correlations between sapwood area and breast height (DBH). The daily consumption of water of each individual tree was proportional to its stem diameter. II. Sap flow dynamics of artificial P.orientalis and water consumption regularity. 1. The diurnal variation of p.orientalis sap flow velocity was all single-peak curves in different seasons. In spring and summer, every day it started from 8:00 and reached the maximum at 10:00.In autumn, the start time was later than that of spring and autumn at about 11:00 and reached the maximum around 13:00-14: 00. However, about the rapid decline time of sap flow, in spring it was the latest, the time was 20:00; in autumn, it was the earliest at about 18:00 and in summer it was19:00. 2.Linear regression indicates that the sap flow velocity from April to May showed a linear correlation with PAR, air temperature, VPD, and the relative humidity, the degree of correlation was as follows: PAR>VPD> Temperature>relative humidity. So the linear expressions of those meteorological factors can be used to estimate the sap flow of P.orientalis. 3. There was exponential function relation between the sapwood area of P. orientali and the ground diameter, so it was used to obtain an estimate of sapwood in the sample plots, which was 4.65 m2. And according to the monthly average velocity of the trees, the water consumption used for transpiration by each P. orientali plantation from april to October was calculated and finally, total water consumption used for transpiration by P. orientali plantation in the growing season from April to October was calculated, which was 1159.6 t·hm-2. III. A comparative analysis of sap flow velocity of two trees 1. In the leaf-flushing period, it shows that sap flow velocity of p.oriental was higher than that of Robinia pseucdoacaci. In the growing season, it shows that sap flow velocity peak of Robinia pseucdoacaci was higher than that of P. orientali. In the early October, the sap flow velocity peak of Robinia pseucdoacaci was higher than that of P. orientali. In mid-October, the sap flow velocity peak of Robinia pseucdoacaci was lower than that of P. orientali. As a result Leaf abscission, the sap flow of Robinia pseucdoacaci become in disorder after October 15-16. 2. Throughout the growing season, the daily water consumption of a single Robinia pseucdoacac and P. orientali was in accordance with the change of its sap flow velocity, that is, from the early growing season through the growing season to the late period of growth, the water consumption of a single Robinia pseucdoaca changed from low consumption, gradually reached the peak and then lowered again. Water consumption of P. orientali was gradually reduced. |
| 公开日期 | 2011-07-01 |
| 源URL | [http://ir.iswc.ac.cn/handle/361005/4134]  |
| 专题 | 水土保持研究所_水保所知识产出(1956-2013) |
| 推荐引用方式 GB/T 7714 | . 黄土丘陵半干旱区典型人工林蒸腾耗水动态研究[D]. 陕西. 中国科学院研究生院. 2009. |
入库方式： OAI收割
来源：水土保持研究所
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