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山东丘陵区苹果园蒸腾耗水规律研究

Law of Transpiration and Water Consumption in Apple Orchard in Shandong Hilly Area

【作者】 耿兵

【导师】 王华田;

【作者基本信息】 山东农业大学 , 森林培育, 2013, 博士

【摘要】 树木整株耗水性的研究历来是树木水分生理学家、生态学家、林学家共同关心的问题,这一问题既是树木水分生理的核心,也是贯穿整个森林生态和森林培育的理论基础之一。近年来,随我国农业种植结构调整,果树栽植面积、果园的投入和产出不断增长,果园的耗水量不断增加。因此认知果树蒸腾规律和准确测定果树蒸腾量,了解果园土壤水分动态,不仅有利于合理制定灌溉制度,保证果树节水、高产、稳产,而且可以制定适合果园的节水、保水手段。本文以山东省丘陵地区苹果园为研究对象,采用热扩散式茎流计、光合测定系统、冠层分析仪、TRIME-FM土壤剖面水分速测仪、微型气象站等先进的仪器,于2009-2010年在山东省肥城市潮泉镇优质红富士苹果园,对苹果树叶片蒸腾特征、果园的气候变化、树干边材液流的时空变化规律、土壤水分的动态变化趋势和果园的水分盈亏变化规律等方面进行了系统试验研究和模拟,取得了以下研究成果:(1)夏季蒸腾作用的高峰期出现较早,而春季、初夏和秋季出现较晚,相应的蒸腾强度初夏季节最高,随后逐渐降低。红富士叶片日平均蒸腾速率的年变化呈单峰趋势,在7月15日达到最高峰,峰值为2.726mmol.m-2·s(-1),11月16日达到最低,为0.5876mmol.m-2·s(-1),两者相差2.139mmol.m-2·s(-1)。各月份红富士叶片日平均蒸腾速率由大到小顺序为6月>7月>8月>4月>5月>9月>10月>11月。红富士苹果树冠不同方位的蒸腾速率,西向叶片具有较高的叶片蒸腾速率,南向叶片次之,再次为东向叶片,北向叶片蒸腾速率最小,但各方向叶片蒸腾速率之间除个别天差异不显著。不同日期环境因子与蒸腾速率的相关性大小和重要程度均不相同,但PAR与蒸腾速率均呈显著和极显著相关关系。从整个生长季节看,大气温度、PAR、GS和CI与蒸腾速率呈极显著相关。(2)红富士苹果离体叶片蒸腾速率是活体叶片的1.07~3.44倍,平均为1.45倍,即红富士苹果潜在最大叶片蒸腾速率是自然状态下叶片蒸腾速率的1.45倍。气孔计法与称重法测定值的比值在日进程上呈现递减趋势,校正系数在日进程上应逐渐递增,校正系数在日进程上分别为0.24、0.32、0.71、0.88、0.83、1.00,平均取值为0.495。气孔计法测定结果的偏离程度在日周期内清晨最大,并随着时间逐渐下降,6:0010:00偏离4.243.11倍,10:0014:00偏离1.401.14倍,14:0018:00偏离1.201.00倍,生长季节平均偏离2.02倍。利用气孔计测定值估测整株蒸腾量,经过校正红富士苹果生长季节的叶片蒸腾量总计为9213kg。(3)红富士苹果的边材液流通量密度日变化过程基本呈现单峰曲线形式,生长季节7月份晴天、阴天和雨天3种典型天气条件下,红富士苹果日周期树干茎流变化过程分别呈单峰曲线、双峰曲线和多峰曲线;晴天液流速率与PAR的相关性最大,阴天和雨天主要受大气温度的影响。整个生长季节来看,液流通量密度月均值从大到小排列顺序为7月﹥6月﹥5月﹥8月﹥9月﹥10月﹥4月。利用Richards模型模拟液流通量密度日周期进程,模型表达式为W=33.573(1-(-30.588) e-0.395t)1/(-0.405),R2=0.99,拟合效果十分理想。整个生长季节内,液流速率与环境因子的滞后时间呈现先下降后上升的趋势。液流速率的变化在整个生长季节内都提前与大气温度的变化,最大可提前4h左右,平均提前1.78h。液流速率的变化在生长季节的5月份到8月初基本呈现提前Par的状态,在其他时间则滞后Par的变化情况;整个生长季节平均滞后0.13h。对晴天、阴天和雨天测定结果分析结果表明:3种天气状况下,液流速率与光合有效辐射和太阳净辐射之间的滞后时间差异性较小,与其它环境因子相比,雨天的滞后时间差异性较大。选择1个晴天的数据做主成分分析并利用处理结果做回归分析表明:经过滞后时间位移处理后的数据所有环境因子都作为了第一主成分,回归分析决定系数为0.932。进行时滞效应处理后的数据相关性更高,其拟合效果也更好。滞后效应处理后回归方程为:y=2.26x-1.42x2。(4)通过对红富士叶片蒸腾和边材液流特征的比较可以得出:4月份、5月份和11月份蒸腾速率较小的月份,叶片蒸腾不是引起树干边材液流的主要因素,水容的存在是叶片蒸腾与边材液流相关性较小的原因。6月份到10月份蒸腾速率较大的月份,叶片蒸腾与树干液流相关性极显著,叶片蒸腾是引起树干边材液流的主要因子。因为有水容的存在,叶片蒸腾峰值出现时间提前或与边材液流峰值出现时间相同。(5)TDP法测定红富士苹果树7月份的月蒸腾量和日平均蒸腾量最高分别为101.75㎜和3.28㎜,4月份的月蒸腾量和日平均蒸腾量最低分别为29.59㎜和0.99㎜。红富士苹果园生长季节果园总蒸散量为682.6mm。7月份果园蒸散量最高为137.19mm,10月份最低为44.95mm,整个生长季节果园蒸散量呈现先上升再下降的趋势。整个果园的果树蒸腾量占果园蒸散的三分之二,而地表蒸发占果园蒸散的三分之一左右。地表蒸发所占果园蒸散量春季最高,尤其是4月份地表蒸发占果园蒸散的70%左右,5月份占50%左右。整个生长季节果园降雨量为598.1mm,水分亏缺84.5mm。彭曼法测定果园生长季节蒸散量为714.27mm,蒸散量最高的月份为6月份,应用彭曼法计算得到的水盈亏数值为果园亏缺116.17mm。应用彭曼法对茎流计法进行调整,调整后果园生长季节水分蒸散量为612.6mm,总计亏缺14mm。(6)苹果园不同深度水分含量呈明显的阶梯状分布,随土壤深度增加,土壤含水量逐渐增加。覆盖秸秆可以提高60cm以上土层的土壤含水量,但减少了60-80cm土层的土壤含水量。对覆盖和不覆盖秸秆的土壤含水量进行差异性分析表明:秸秆覆盖只对0-20cm和60-80cm土层含水量产生的显著的影响。

【Abstract】 The study on water consumption of the whole tree has always been a common issueconcerned by physiologists, ecologists, foresters. This problem is not only the core of treewater physiology, but also one of the theoretical bases throughout the entire forest ecosystemand forest cultivation. In recent years, with the structure adjustment of agricultural planting,the increasing area of the fruit planting and orchards’ inputs and outputs, the waterconsumption of orchards is increasing. Therefore, cognize the law of fruit tree transpirationand accurate determination of fruit tree’s transpiration, understand the dynamic of the orchardsoil is beneficial to establishing reasonable irrigation system to ensure that the water saving,high yield, stable yield and can be suitable for orchard water-saving.Taking apple orchard of hilly area in Shandong as the study object, some research resultshas been made, through system test research and simulation on transpiration features of Appleleaves, climate changes of orchard, trunk sapwood liquid flow of spatio-temporal changes law,dynamic changes trend of soil water and the Space-time Variation Regularities of Soil WaterSurplus or Lack of the orchard, using Thermal Dissipation Sap Flow Probe portablephotosynthesis system plant canopy analyzer TRIME-FM soil profile moisture measureportable-meteorological station in the high-quality red Fuji apple orchards in Chaoquantown,Feicheng city, Shandong province during2009-2010.(1) The peak of transpiration comes early in summer and a late in spring, early summerand autumn. Highest transpiration intensity comes in early summer, then gradually decreasing.The annual variation of day average transpiration rate of Red Fuji vane showed a single peaktrend. The max peak value is2.726mmol.m-2·s(-1) in July15, the mix0.5876mmol.m-2·s(-1) inNovember16, a difference of2.139mmol.m-2·s(-1).The order from largest to smallest ofaverage daily transpiration rate of Red Fuji leaves is June> July> August> April> May>September> October>November.Transpiration rate of different orientation of Red Fuji apple is different. The descendingorder is west, south, east and north. Except for the few days, the leaf transpiration rate ofdifferent direction is not significant. The leaf transpiration rate trend of different orientationhas different characteristics in different periods.It is different between environmental factors in different date and the relevance andimportance of the transpiration rate. But PAR and transpiration rate showed a significant and extremely significant correlation. From the point of view throughout the entire growingseason, it is significantly correlated between transpiration rate and atmospheric temperature,PAR, GS, CI. PAR and transpiration rate correlation reached0.689.(2) Transpiration rate of detached leaf is1.073.44times of living leaves, an averageof1.45times. That is to say, the maximum potential transpiration rate is1.45times of thestate of nature. The ratio of the porometer method and gravimetric method show a decreasingtrend in daily course, while the correction factor gradually increasing. The correction factorsin daily course are0.24,0.32,0.71,0.83,0.88,1.00, an average value of0.495. Departuredegree of the measured results by Porometer method shows maximum in the early morningduring daily periodicity and decreased over time. It deviates from4.243.11times during6:0010:00,1.401.14times during10:0014:00,1.201.00times during14:0018:00, anaverage of2.02times in the growing season. The leaves transpiration rate is9213kg aftercorrection in growing season with porometer measurements.(3) Trunk sapwood liquid flow flux density shows a single trend in dailycourse. Change of trunk sap flow in daily course shows a single peak curve in clear day, abimodal curve in overcast day, a multi peak curve in rainy day during growing season inJuly.It is on clear day that the sap flow velocity significantly correlated with PAR, since thecorrelation is influenced by atmospheric temperature on overcast and rainy day. Throughoutthe growing season, the month mean values of sapwood liquid flow flux density showed thatJuly>June>May>August>September>October>AprilThe model for the daily course of sapwood liquid flow flux density is W=33.573(1-1(-30.588) e-0.395t)1/(-0.405),R2=0.99, perfect fitting effect,basing on the Richards model.Sap flux density lag behind environmental factors, but the time is different in one day.The lag time of different seasons has certain regularity on the whole, which is different withdifferent environmental factors. Related to atmospheric temperature and atmospheric relativehumidity, sap flux density shows a delay phenomenon. The annual change law of lag timeshows a tendency that increases first and then decreases gradually. The maximum appears inMay and June, the minimum in September. Related to soil temperature, the annual change lawof sap flux density shows a positive number and then a negative number, with a tendencydecrease first and then increase gradually. Related to wind speed and soil water content thetendency increase first then decrease gradually and increase again, Related to PAR increasefirst and then decrease gradually. The maximum monthly averaged values of lag time are both12min in June and July. Minimum appears in September, is-24min. Related to environmental factors,Lag Time of Sap flux density are different between deferent trees, except atmospherictemperature,differences of lag time is not significant.(4) Red Fuji apple’s transpiration rate is determined by TDP, maximum is in July,the rateis101.75㎜and daily average is3.28㎜, minimum is in April the rate is29.52㎜and dailyaverage is0.99㎜. In growing season, transpiration rate of the Red Fuji apple orchard is682.6㎜, and July is the maximum, the rate is137.19㎜, October is the minimum, the rate is44.95㎜. The rate in the whole growing season shows a tendency which increase first thendecrease. Apple trees’ transpiration rate takes two-thirds of whole orchard; ground surfaceflux takes one-thirds. Ground surface flux rate takes highest of orchard is in spring, especiallyin April, it is about70%, and in May it is about50%. Rainfall of the orchard in the wholegrowing season is598.1㎜, water deficit is84.5㎜.Transpiration rate of the orchard in growing season is714.27㎜determined by PenmanMethod, maximum is in June, water deficit of the orchard is116.17㎜. Useing PenmanMethod to improve stem-flow gauge, the transpiration rate of the orchard in growing season is612.6mm, whole water deficit is14㎜(5) The apple orchard’s moisture content has a significant difference in different depth,with the increase of soil depth, soil moisture content increased gradually. Straw-mulching canimprove soil water content in the layers of below60cm, but reduce soil water content in thelayers of60-80cm. The analysis shows that straw-mulching only obviously affected the soilwater content in the layers of10-20cm and0-80cm by straw-mulch.

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