基于热扩散技术的三倍体毛白杨单木及林分蒸腾耗水研究

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于热扩散技术的三倍体毛白杨单木及林分蒸腾耗水研究 DOI: 10.5846/stxb201409171846 作者: 作者单位: 国家开放大学,北京林业大学,黑龙江省大庆市林业局,北京林业大学,北京林业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家林业公益性行业科研专项经费重大项目(201004004);北京林业大学"985"优势学科创新平台开放基金(000-1108003) Study of transpiration and water consumption of triploid Populus tomentosa at individual tree and stand scales by using thermal dissipation technology Author: Affiliation: The Open University of China,Beijing Forestry University,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:定量分析单木及林分的蒸腾耗水特征,是林木水分管理的关键环节。采用热扩散式边材液流检测技术,结合自动气象站,对三倍体毛白杨树干边材液流及环境因子进行了连续2年的动态观测。结果表明:(1)单株尺度上,三倍体毛白杨边材液流速率日变化在晴天表现为"单峰型",关键影响因子为水汽压亏缺(VPD)和太阳辐射(Qs),日平均液流速率在4-10月分别为0.65×10-3、2.12×10-3、2.09×10-3、1.78×10-3、1.84×10-3、1.76×10-3、1.04×10-3 cm/s;(2)林分尺度上,三倍体毛白杨在2008、2009年(栽植第4年和第5年)的蒸腾耗水量分别为339.52和410.62 mm,主要影响因素为气孔导度(Gc)、相对湿度(RH),以及VPD;(3)多元线性回归模型可以较好的模拟三倍体毛白杨边材液流速率对环境因子的响应特征(P < 0.01,2008年),模型预测值较实测值偏大6.39%(2009年),二者极显著线性相关(R2=0.910,Sig.=0.00054,n=1008)。 Abstract:Quantitative analysis of the transpiration and water consumption characteristics at the individual tree and stand scales of forests is critical for forest water management. Developing fast-growing and high-yielding poplar plantations has been identified as a major solution to the shortage of wood fibers in China, because of the strong demand for fibrous products for the large population and limited land resources. The triploid Populus tomentosa has been one of the most widely planted species in recent years due to its superior growth vigor and high timber yield. Accurately measuring the transpiration and water consumption of trees is essential for regulating water use in triploid P. tomentosa plantations. In this study, thermal dissipation probe (TDP) monitoring technology was combined with an automatic weather station to investigate the transpiration and water consumption of triploid P. tomentosa at the individual tree and stand scales over two years. The response of sap flow velocity (Vsp) in P. tomentosa trees to environmental factors, including solar radiation (Qs), air temperature (Ta), relative humidity (RH), wind speed (WS), soil water content (SWC), soil temperature (Ts), and vapor pressure deficit (VPD), were analyzed using a multiple linear regression model. The results showed that (1) the daily variation in sap flow velocity in individual P. tomentosa trees was significantly affected by the Qs and VPD. Diurnal variation in Vsp for individual trees had a unimodal pattern on sunny days. The flow rate rose from nearly zero at sunrise to a maximum at around 13:00 local time and decreased gradually to nearly zero by midnight. In the growing season (from April to October), the average Vsp for each month was 0.65 × 10-3, 2.12 × 10-3, 2.09 × 10-3, 1.78 × 10-3, 1.84 × 10-3, 1.76 × 10-3, and 1.04 × 10-3 cm/s, respectively. The results of the correlation analysis showed that the Vsp correlated significantly (α = 0.01) with the Qs, Ta, WS, RH, SWC, Ts, and VPD. With the exception of RH, all correlations were positive. The VPD and Qs had stronger effects on Vsp than SWC at a daily variation scale. (2) The water consumption of the P. tomentosa stand was 339.52 and 410.62 mm during the growing season in the fourth and fifth years after planting (2008 and 2009), respectively. The water consumption at the stand level was significantly affected by stomatal conductance (Gc), RH, and VPD. The variation in average daily water consumption followed a "low-high-low" unimodal pattern in the growing season and high water consumption values were recorded in August 2008 and June 2009. The main factors that drove the seasonal changes in water consumption in the stand were Gs, RH, and VPD. Lastly, (3) the regression model, with the measured environmental factors as independent variables, explained the variation in Vsp well during the growing season in 2008 (P < 0.01). When the constructed model was used to predict the Vsp in the growing season in 2009, the simulated values correlated well with the measured values (R2 = 0.910) but was 6.39% higher than the measured values on average. 参考文献 相似文献 引证文献