CHINC2012-G2-John Hoyt

型 号品 名价格颜 色产品图片包 装数量/箱产品参数LM-S08U 精灵19黑色40/箱USB接口/1000DPI高分辩率/小巧精美时尚外观/移动笔记本电脑专用鼠标。

LM-8007P/U 战鹰17/18全黑 60/箱1000CPI 原相芯片引擎内置加重块设计.商务，学校，办公LM-W005P/U 狙击精英22/23全黑60/箱网吧专用抗暴鼠标LM-8315U 飞鹰22红/蓝60/箱1000CPI 安捷伦原装芯片,两侧大按键设计,表面抛光工艺处理,内置重块设计.3D镀金滚轮.商务，学校，网吧40/箱USB接口/1000DPI高分辩率/小巧精美时尚外观/移动笔记本电脑专用鼠标。

商务，办公笔记本LM-S09U 有线光电鼠标 更多新品敬请关注：/精灵貂23黑蓝/黑红/白/草绿/绿/银红色LM-8509U 蛇雕25黑色60/箱1000CPI 3D网吧游戏鼠标，超酷外形，加重稳定，手感超爽，Pu光面外表处理。

网吧，个人游戏LM-EM22U 天煞孤鹰28铁灰60/箱安捷伦高端游戏鼠标芯片引擎,游戏专用鼠标,5D按键操作更方便.网吧，个人游戏LM-W003P/U 网霸3号25/27黑色60/箱1000CPI 采用原相原装芯片,两侧大按键设计,表面抛光工艺处理,内置重块设计.3D镀金滚轮.商务，学校，网吧LM-8328U 金刚38黑/白40/箱专为游戏而生，6D多功能按键设计，DPI自由切换适应各类竞技游戏，自定义按键设定。

游戏专用LM-8530U 即将上市40/箱入门游戏必选，6D多功能按键设计，DPI自由切换适应各类竞技游戏，专用线材与USB接头。

入门级游戏专用2.4G无线鼠标新新LR-6800睿敏45黑/蓝/黄40/箱采用凌阳方案，稳定省电，外观大小适中，5D快捷按键，配带方便时尚，DPI4档自由切换500/1000/1600/2000。

商务，办公，笔记本LR-EM28睿敏40蓝/黄/白/绿40/箱500/1000/1600CPI 3档自由切换EMC高端无线方案 商务，办公，笔记本LR-530睿敏32蓝/黑60/箱简洁大方三键大众无线鼠标 商务，办公，笔记本LR-9103睿敏45红/黑40/箱简洁大方五键大众无线鼠标 商务，办公，笔记本键盘产品LK-307P/U爽手王19/21全 黑20/箱标准普通107键，外观简节大方，静音防水设计。

•New Castle, DE USA +1-302-427-4000•Lindon, UT USA+1-801-763-1500•Hialeah, FL USA+1-305-828-4700•Crawley, United Kingdom +44-1293-658900•Shanghai, China +86-21-64956999•Taipei, Taiwan +88-62-25638880•Tokyo, Japan +81-3-5759-8500•Seoul, Korea +82-2-3415-1500•Bangalore, India +91-80-2319-4177-79•Paris, France +33-1-30-48-94-60•Eschborn, Germany +49-6196-400-600•Brussels, Belgium +32-2-706-0080•Etten-Leur, Netherlands +31-76-508-7270•Sollentuna, Sweden +46-8-555-11-521•Milano, Italy +39-02-265-0983•Barcelona, Spain +34-93-600-93-32•Melbourne, Australia +61-3-9553-0813•Mexico City, Mexico +52-55-52-00-18-60L OCAL O FFICES0000ARES-G 21235711143541AR R HEOMETERS15161718192021TM 27354112Test stationTransducer Force/Torque Rebalance Minimum Torque in Oscillation 0.05 μN.m Minimum Torque in Steady Shear 0.1μN.m Maximum Torque 200 mN.m Torque Resolution 1nN.m Normal/Axial Force Range 0.001to 20 N Motor Brushless DC Motor Bearings Jeweled Air Strain Resolution 0.04 μrad Min Angular Displacement in Oscillation 1 μrad Max Angular Displacement in Steady Shear UnlimitedAngular Velocity Range 1 x 10-6rad/s to 300 rad/s Angular Frequency Range 1 x 10-7to 628 rad/s Step Change in Velocity 5 ms Step Change in Strain 10 ms Temperature SystemsSmart Swap Standard Force Convection Oven, FCO -150 to 600˚C FCO Camera Viewer Optional Peltier Plate -40 to 180˚C Sealed Bath -10 to 150˚CT ECHNICAL SPECIFICATIONSARES-G2 T ECHNOLOGYTorque and Normal Force Transducer34F ORCE R EBALANCE M OTOR ANDM AGNETIC S USPENSIONN ON -C ONTACT T EMPERATURES ENSOR E LECTRONICST ORQUE R EBALANCE M OTORT ORQUE /N ORMAL F ORCER EBALANCE E LECTRONICSR ADIAL A IR B EARINGU PPER G EOMETRY MOUNT5ARES-G2 T ECHNOLOGY Advanced Brushless DC Drive MotorA high-resolution optical encoder measures and controls angular deflection over exceptionally wide rangesgreatly improving traditional oscillation and transient strain-controlled testing performance. The opticalencoder allows testing to be started in any position for all test modes, and with no preferred homeposition in oscillation, tests are seamlessly combined with smooth transition and timely response.T HRUST A IR B EARINGR ADIAL A IR B EARINGB RUSHLESS DC M OTORO PTICAL E NCODERN ON -C ONTACTT EMPERATURE S ENSORE LECTRONICSL OWER G EOMETRY MOUNTD UCTILE I RON FA CTIVE T EMPERATURE C ONTROLThe ARES-G2 incorporates our newly-patented, non-contact temperature sensor technology for active measurement and control of both the upper and lower plate temperature. Platinum Resistance Thermometers (PRT) can be installed into the shaft ofboth the motor and transducer. When installed, the PRTconnector engages a micro printed circuit board (PCB) on the rotating shaft. The tip of the PRT is placed in intimate contact with the center of an upper cone or plate and/or lower plate geometry. The PRT senses the temperature and transmits the signal to a secondary coil housed in the stationary part of the transducer and/or motor assemblies. The ability to measure and control temperature at the surface of both plates is unique patented technology. This frictionless technology enables temperature sensing on the transducer side with no impact on sensitivity, and on the motor assembly, allows for greater accuracy in small amplitude oscillation testing. Temperature control and measurements are made at the testing surface, which is in intimate contact with thesample, without impacting the measurement.TRIOS S OFTWARE AND E XTREME T ESTING F LEXIBILITYAn important new feature of the ARES-G2 is a new level of testing freedom and flexibility. All key components of the rheometer (motor, transducer, data acquisition, environmental controls, axial slide etc.) are independent units with their own intelligence, all of which are orchestrated by test instructions programmed with new TRIOS software interface. While this versatile and intuitive software interface provides fast and simple programming of well known general procedures for traditional testing, (eg. strain/frequency sweeps, stepwell-known strain, etc.), rigid limitations of pre-programmed test modes at the instrument level no longer exist. Instead, test or test sequencespecific instrument instructions are easily programmed in countless combinations and d ownloaded prior to the start of the experiment.F ULLY I NTEGRATED F AST D ATA A CQUISITIONThe ARES-G2 provides fully integrated fast data acquisition for transient and oscillatory testing using 5 fast data channels. This allows simultaneous collection of angular displacement, torque and normal force in all test modes. The high data sampling rate of 8kHz in oscillation mode provides better resolution of both the magnitude and phase of the measured signals and allows better harmonic resolutionwith accurate evaluation up to the 10th harmonic.T OUCH S CREEN AND K EY P ADThe ARES-G2 features a color touch screen userinterface mounted on the front of the test station.This graphical interface adds a new dimensionin ease-of-use. Interactive activities such as gapzeroing, sample loading and setting temperature canbe conveniently performed at the test station. It alsodisplays instrument status and test information (torque,normal force, sample temperature) and provides easyaccess to system information such as settings anddiagnostic reporting.P ELTIER P LATEThe Peltier Plate is a smart swap temperature control option providinga temperature range of –40 to 180 °C, with a maximum heating rate of30 °C/min, and temperature accuracy of +/- 0.1 °C. A platinum resistance thermometer (PRT) sensor is positioned in the middle of the lower sample plate and ensures accurate measurement and control of sample temperature. It is the most common system for standard parallel plate and cone and plate testing of structured fluids. The open design facilitates easy sample loading and cleaning of geometries. A new optional Solvent Trap and Purge Cover accessory is available for use with the Peltier plate. When used as a solvent trap, (to keep samples from volatilizing (drying) during experiments), the sample is fully isolated from the surrounding atmosphere by a fluid seal at the top (transducer side) and permanent seal at the bottom (motor side). A circular well containing solvent can also be attached and placed in contact with the Peltier plate surface. This allows the solvent to evaporate and create a saturated atmosphere inside the enclosure. Gases can be introduced through the purge ports. For example a dry air or nitrogen purge keeps moisture from condensing around the sample while testing below room temperature.R ECIRCULATING F LUID B ATHThe Recirculating Fluid Bath option can be used with parallel plate, cone and plate, and concentric cylinder geometries. Concentric cylinders are especially useful for very low viscosity fluids, dispersions of limited stability and for applications where fluid/solventevaporation may be a concern. The option requires a computer-controlled fluid circulator for automated temperature control operation. The temperature range is –10 to 150 °C with appropriate circulator and circulating fluid.ARES-G2 A CCESSORIESMinimum Torque Oscillation CR 0.003 μN.mMinimum Torque Oscillation CS 0.003 μN.mMinimum Torque Steady CR 0.01 μN.mMinimum Torque Steady CS 0.01 μN.mMaximum Torque 200 mN.mTorque Resolution 0.1 nN.m [1]Motor Inertia 18 μN.m.sAngular Velocity Range CS 0 to 300 rad/sAngular Velocity Range CR 1.4E -9to 300 rad/sFrequency Range 7.5E -7to 628 rad/sDisplacement Resolution 25 nradStep Change in Velocity 7 msStep Change in Strain 30 msDirect Strain Control Standard [2]Thrust Bearing MagneticNormal/Axial Force Range 0.005 to 50 NSmart Swap™StandardSmart Swap Geometry StandardPeltier Plate -40 to 200 °C [3]Environmental Test Chamber (ETC)-160 to 600 °CETC Camera Viewer OptionalConcentric Cylinder -20 to 150 °C [3]Peltier ControlUpper Heated Plate -30 to 150 °C [3]Electrically Heated Plate (EHP)-70 to 400 °C Camera Option with StreamingVideo and Image Capture OptionalT ECHNICAL S PECIFICATIONSCR - Controlled Rate Mode CS - Controlled Stress Mode [1] Internal Resolution for D to A converter at torque of 0.1 µN.m [2] Direct Strain Control provides single cycle oscillation and continuous oscillations during experiments.[3] Lower temperature limits require use of a suitable fluid in an external circulator.Minimum Torque Oscillation CR 0.03 μN.mMinimum Torque Oscillation CS 0.1 μN.mMinimum Torque Steady CR 0.05 μN.mMinimum Torque Steady CS 0.1 μN.mMaximum Torque 200 mN.mTorque Resolution 1 nN.m [1]Motor Inertia 15 μN.m.sAngular Velocity Range CS 0 to 300 rad/sAngular Velocity Range CR 1E -8to 300 rad/sFrequency Range 7.5E -7to 628 rad/sDisplacement Resolution 40 nradStep Change in Velocity 25 msStep Change in Strain 60 msDirect Strain Control Standard [2]Thrust Bearing Porous Carbon AirNormal/Axial Force Range 0.005 to 50 NSmart Swap™StandardPeltier Plate -40 to 200 °C [3]Environmental Test Chamber (ETC)-160 to 600 °CConcentric Cylinder -20 to 150 °C [3]Peltier ControlUpper Heated Plate -30 to 150 °C [3]Electrically Heated Plate (EHP)-70 to 400 °CT ECHNICAL S PECIFICATIONSCR - Controlled Rate Mode CS - Controlled Stress Mode [1] Internal Resolution for D to A converter at torque of 0.1 µN.m [2] Direct Strain Control provides single cycle oscillation and continuous oscillations during experiments.[3] Lower temperature limits require use of a suitable fluid in an external circulator.Minimum Torque 0.1 μN.m Maximum Torque 150 mN.m Torque Resolution 1 nN.m [1]Motor Inertia 15 μN.m.s Angular Velocity Range CS 0 to 300 rad/s Angular Velocity Range CR 1.00E -7to 300 rad/s Frequency Range 7.50E -7to 628 rad/s Displacement Resolution 40 nrad Step Change in Velocity 25ms Step Change in Strain 6 0ms Thrust Air Bearing Porous Carbon Smart Swap TM Standard Peltier Plate -40 to 200 °C [2]Peltier Plate Camera Optional Peltier Concentric Cylinder -20 to 150 °C [2]Upper Heated Plate -30 to 150 °C [2]Electrical Heated Plates -70 to 400 °C[1] Internal Resolution for D to A converter at torque of 1 µN.m [2] Lower temperature limits require use of a suitable fluid in an external circulator.T ECHNICAL SPECIFICATIONSAR T ECHNOLOGY The AR series represents a family of rheometers uniquely designed to deliver optimum system performance.6 R IGID O NE-P IECE A LUMINUM C ASTING& L INEAR B ALL S LIDEAR-G2 T ECHNOLOGYM AGNETIC T HRUST B EARINGWhy a magnetic bearing? Larger gaps in the absence of a continuous flow of pressurized air translates to unprecedented low levels of friction in the bearing. More importantly, the ability to control and measure torques in the nN.m range. No other rheometer can boast such low-end torque sensitivity. The larger gap in the thrust bearing is robust and not susceptible to contamination. The additional benefits of the magnetic bearing over traditional air bearing designs are the following:• Ultra low torques applied to the sample• Smaller sample volumes can be used• Ability to probe delicate material structures• Study of low viscosity materials over abroad range of conditionsP ATENTED D RAG C UP M OTOROur new patented advanced drag cup motor is designedto further reduce system friction by increasing the motor gap by 100%. Dramatic improvements in low end torque performance are realized without compromising high-end performance. The motor delivers enhanced transient response and an extended angular velocity control range. The motor incorporates a patented drag cup temperature sensor. For the first time in any rheometer design, the temperature of the drag cup is measured, ensuring the mostaccurate torque output.ACTIVE T EMPERATURE C ONTROL(ATC)The AR-G2 Electrically Heated Plate (EHP), Upper Heated Plate (UHP),and Dry Asphalt System all incorporate our new patented(1)non-con-tact temperature sensor for active measurement and control of theupper plate temperature, using a special draw rod. The draw rodhouses a micro PCB and Platinum Resistance Thermometer. AR-G2 T ECHNOLOGYICRO PCBP RIMARY CS ECONDARY C OIL HS SaS MART S WAP TM A CCESSORIESC ONCENTRIC C YLINDERConcentric Cylinders are commonly used for very low viscosity fluids,dispersions of limited stability, and applications where fluid/solventevaporation may be a problem. The Smart Swap Concentric Cylindersystem features Peltier temperature control and provides a temperaturerange of -20 to 150 °C with heating rates up to 15 °C/min.PPER H EATED P LATE(UHP)S MART S WAP TM A CCESSORIESE LECTRICALLY H EATED P LATES(EHP)The EHP is a Smart Swap TM temperature option that provides active heating and cooling of parallel plate and cone and plate geometries. The EHP is perfect for rheological characterization of polymer melts up to a maximum temperature of 400 °C. Otherfeatures include an environmental cover and heated purge gasand an optional Gas Cooling Accessory for temperature controlto -70˚C. An optional clear purge cover is available for sampleviewing and integration with camera viewer. Additionally, for theAR-G2, the EHP offers patented Smart Swap G eometries andnewly patented Active Temperature Control, ATC. ATC makes theAR-G2 EHP the only electrically heated plate system capable ofdirect temperature control of both the upper and lower plates.S MART S WAP TM A CCESSORIESD YNAMIC I NTERFACIAL S HEARR HEOLOGY U SING THE AR-G2The dynamic interfacial shear moduli G’ and G” are used tomonitor the network structure build-up, resulting from the adsorption of proteins at the interface. Proteins unfold at the interface and, therefore, are crucial to the stability of emulsions and foams. The measurement is done with a Du Noüy Ring, positioned at the interface of two liquids, or a liquid and air in a circular glass dish. The ultra-sensitive,nano-torque range of the AR-G2 rheometer is required to make these measurements. Figure 1 shows the dynamic storage modulus of this material continuously increases as the protein migrates to the surface and forms a network structure.0.030.025 0.02 0.0150.01 0.005 050100 150time (minutes)G ‘, G ’’ (N /m )34F LOW C URVE FOR D ISPERSIONS F LOW C URVE FOR P OLYMERSV ISCOELASTIC P ROPERTIES S TRAIN S WEEPD YNAMIC M ECHANICAL P ROPERTIES OF S OLIDS IN T ORSION T RANSIENT T ESTS(C REEP AND S TRESS R ELAXATION)D YNAMIC O SCILLATION ON L OW V ISCOSITY F LUIDS U SING ARES AR-G2 N ANO-T ORQUEM EASUREMENTS IN S TRESS& S TRAIN C ONTROL O SCILLATIONS TRESS AND S HEAR R ATE R AMPSE XTENSIONAL V ISCOSITYM EASUREMENTS ON ARESC REEP AND R ECOVERY OF A V ISCOELASTIC F LUIDS TRESS G ROWTH IN A T RANSIENT S TEP R ATE E XPERIMENT41© 2009 TA Instruments. All rights reserved.。

FTF2012中国站的演讲一览表FTF-AUT-F0014 星期三 09:30 1 小时 China Ballroom B飞思卡尔演讲者:Hua Qian: Freescale Semiconductor 课程名称:通过Qorivva MCU解决方案应对复杂车辆网络的挑战现代车辆网络结构明显变得更加复杂了。

除了传统的CAN和LIN总线系统外，视频和多媒体系统的传输也促使高带宽网络，如MOST、 FlexRay及以太网等的需求。

汽车OEM越来越关心网络维护及软件的复杂性。

此次会议将探讨各种汽车网络架构及飞思卡尔Qorivva 32位MCU产品系列如何帮助OEM应对这些挑战。

类别:汽车电子子类别:车身电子架构:微处理器: 微处理器, 8位微控制器, 16位微控制器, Qorivva （5xxx) Power Architecture® 微控制器课程级别:基础课程类型:课程培训语言:EnglishFTF-AUT-F0020 星期二 15:30 1 小时 Summit Ballroom A飞思卡尔演讲者:Andres Barrilado, SASD Firmware and Apps Engineer: Freescale Semiconductor 课程名称:飞思卡尔与博世联合开发的安全气囊参考平台概况一个由飞思卡尔与罗伯特•博世有限公司汽车电子产品部门联合设计与开发的安全气囊控制系统参考演示器。

该演示器由1个主ECU、4个符合AKLV-27标准可支持PSI5的卫星冲撞传感器、模拟安全气囊引爆器、基于PC的图形用户界面及参考手册组成。

主ECU中包括飞思卡尔MPC5406P MCU及博世CG147安全气囊ASSP。

主ECU可支持飞思卡尔MMA65xx双轴传感器或博世SMA560双轴传感器。

此外，ECU中还包括由基本功率模式控制与设备启动程序、操作安全程序及面向图形用户界面的串行数据交换程序组成的软件包。

ComprehensiveExperience OverviewFloating Production, Storage & Offloading (FPSO) systems2013 ENQUEST BRITAIN Ltd. UKCS/ALMA/GALIAFIELDInternal Turret76UISGE GORM95.26357.000 bopd2011 ENI KITAN FIELDDEVELOPMENTTIMOR LESTE 325GLAS DOWR89,56240.000 bopd +22 MMscfd(gaslift).2010 CACT HUIZHOU FIELDDynamic Positioned90 MUNIN60.000 bopd2009 NEXEN NORTH SEA U.K.,ETTRICK FIELD,UKDisconnectableTurret115AOKA MIZU105,00030,000 bopd20 MMscfd*) 2005 EXXON MOBILCENTRAL NORTHSEA, NORWEGIANSECTOR126JOTUN92,00070,000 bopd68 MMscfd**) 2004 SHELL UK LTDNORTH SEA U.K.,PIERCE FIELD,UKDisconnectableTurret85HÆWENE BRIM103,00070,000 bopd110 MMscfd2004 CONOCOPHILLIPS XIJIANG FIELD,CHINADynamic Positioned100MUNIN103,00060,000 bopd**) 2004 STATOIL/CNOOCLUFENGInternal Turret(APL)300MUNIN103,00060,000 bopd2003 PETRO SA SOUTH AFRICA/SABLE FIELDInternal Turret102GLAS DOWR105,00090,000 bopd80 MMscfd1999 TALISMAN NORTH SEA U.K. /ROSSInternal Turret100BLEO HOLM100,000100,000 bopd58 MMscfd1997 AMERADA HESS NORTH SEA U.K. /DURWARD &DAUNTLESSInternal Turret90GLAS DOWR105,00060,000 bopd85 MMscfd1995 AMERADA HESS NORTH SEA U.K. /FIFEInternal Turret70UISGE GORM100,00057,000 bopd20 MMscfd1990 OCCIDENTAL CHINA / LUFENGCALM with MooringHawser330AYER BIRU45,00030,000 bopd1989 MAXUS ENERGY INDONESIA /INTANSpread Mooring42LAN SHUI70,00060,000 bopd1989 MARATHONPETROLEUMAUSTRALIA /TALISMANCALM with MooringHawser80ACQUA BLU70,00040,000 bopd1988 AGIP ANGOLA /SAFUEIROSpread Mooring40ACQUA BLU70,00040,000 bopd1987 AMOCO CHINA / LIUHUACALM with MooringHawser+ 300LAN SHUI70,00060,000 bopd1987 AMOCO GABON / GOMBEMARINSpread Mooring20ACQUA BLU70,00040,000 bopd1985 MONTEDISON ITALY / MILACALM withWishbone Yoke50ACQUA BLU70,00040,000 bopd*) Acquired 55% ownership in Jotun FPSO**) Purchased the Munin and Haewene Brim from NavionFloating Storage & Offloading (FSO) systems1993 TOTALEXPLORATION &PRODUCTIONTHAILAND /BONGKOTInternal Turret80LAN SHUI26,0001989 SOVEREIGN OIL &GAS PLCUNITED KINGDOM /EMERALDTripod Wishbone150AILSA CRAIG200,0001986 OCCIDENTAL /ECOPETROLCOLOMBIA /COVENASCALM Wishbone35FSO COVENAS390,0001982 PHILLIPSPETROLEUMIVORY COAST /ESPOIRCALRAM87TT PHILLIPS230,000Internal Turrets2006/2007 BP NORGESKARV(FEED CONTRACT)370 200,000 2003 PETROSA SABLE FIELD, SOUTH AFRICA 100(GLAS DOWR)105,000 1999 PETROBRASBRAZIL / MARLIM(FSO P38)1,020 270,0001999 AMERADA HESS /SHELLUNITED KINGDOM / TRITON 92 105,0001999 PETROBRASBRAZIL / RONCADOR(FSO P47)815 280,0001999 ESSO CENTRAL NORTH SEA,NORWEGIAN SECTOR / JOTUN126 92,0001998 TALISMAN NORTH SEA U.K. / ROSS 100(BLEO HOLM)100,0001998 PETROBRASBRAZIL / MARLIM(FPSO P37)900 269,000 1998 PETROBRAS BRAZIL / MARLIM 163 282,7501997 AMERADA HESS NORTH SEA U.K. / DURWARD &DAUNTLESS90(GLAS DOWR)105,0001996 CONOCO NORTHSEAU.K. / MCCULLOCH 150 100,000 1995 AMERADA HESS NORTH SEA U.K. / FIFE 70(UISGE GORM)100,0001993 TOTAL EXPLORATION &PRODUCTIONTHAILAND / BONGKOT 80LAN SHUI26,000Disconnectable Turrets2009 NEXEN NORTH SEA U.K., ETTRICKFIELD, UKCS 115 (AOKAMIZU)105,000External Turret Mooring systems2013/2014 EXXONMOBIL (MWCSCompany)GULF OF MEXICO 150-1500 AFRAMAX2011 STX Heavy IndustriesCo. LtdKorea 45 FSU 341,0002009 TALISMAN / MISC BUNGA ORKID FIELD 55 “MT FSO ORKID”100,0472006PETRONAS / MISC ABU CLUSTER FIELD61 “MT ARMATA” AFRAMAX89,920Calm Buoy systems (Turret Buoys)2015 ADMA – OPCO Sataz al-Razboot (SARB), ZirkuIsland28 320,0002014 PETROBRAS Tefran 25 80,000-120,000 2014 PETROBRAS Tefran 25 80,000-120,000 2014 PETROBRAS Tefran 25 80,000-120,000 2013 PDVSA TAECJAATerminal,Venezuela25 300,0002013 PDVSA TAECJAATerminal,Venezuela28 300,000 2013 PETROBRAS Brazil, Campos Basin 70 350,0002013 PETROBRAS Brazil, Campos Basin 70 350,0002012 FAPCO Fujairah, UAE 40 50,000 – 150,0002012 PDVSA VENEZUELA 16 80,000 2012 CPC Russia, Novorossiysk 58 15,000 - 300,0002011 CAIRN ENERGY INDIA 28 120,0002010 ECOPETROL COLUMBIA 25 350,0002010 ECOPETROL COLUMBIA 35 350,0002010 HPCL-INDIA VISAKHAPATNAM-INDIA 35 320,000 2009 BEDB MUKIM LIANG BRUNEI 25 46,0002010 ADCOP - ABU DHABI,UAEFUJAIRAH, UAE 35 320,0002010 ADCOP - ABU DHABI,UAEFUJAIRAH, UAE 52 320,0002010 ADCOP - ABU DHABI,UAEFUJAIRAH, UAE 54 320,0002009 PETRONAS CARIGALI(TURKMENISTAN) SDNKIYANLI (KASPIAN SEA,TURKMENISTAN)1712,0002009 BRUNEI DEVELOPMENTBOARDBRUNEI SERIA 25 85,0002009 ROMPETROL BLACKSEA 25 165,0002009 ENI BLACKTIP,AUSTRALIA27350,000 2009 MAERSK OIL QATAR BLOCK 5, QATAR 60-63 500,0002009 MAERSK OIL QATAR BLOCK 5, QATAR 60-63 500,0002009 MAERSK OIL QATAR BLOCK 5, QATAR 60-63 500,0002008 BP TRINIDAD ANDTOBAGOGALEOTA TERMINAL, TRINIDAD29 150,0002008 AL-KHAFJI JOINTOPERATIONS (KJO)AL-KHAFJI Terminal, SaudiArabia23 300,0002007 QATAR GAS RAS LAFFAN TERMINAL 37 320,000 2007 QATAR GAS RAS LAFFAN TERMINAL 37 320,000 2007 THAI OIL, THAILAND SRI-RACHA TERMINAL 30 220,0002007 KOCHI REFINERIESLIMITEDOFFSHORE COCHIN 30 300,0002006 ABU DHABI OIL CO.LTD, JAPAN (ADOC)MUBARRAZ OIL FIELD 19330,0002005 TPPI INDONESIA TUBAN AROMATIC PLANT,INDONESIA50 185,0002005 PEREMBACONSTRUCTIONMELUT BASIN OILDEVELOPMENT PROJECT,SUDAN55 300,0002005 ADMA-OPCO DAS ISLAND, UAE 26 360,000 2004 OXXO SA La Libertad Refinery, EQUADOR 15 45,000 2004 SADRA GROUP ASSALUYEH, IRAN 45 250,0002004 BHP BILLION ANGOSTURA, TRINIDAD 25 150,000 2004 AGIP GAS B.V. WEST LIBYA/WAFA 26 30,000 - 80,000 2002 AMERADA HESS EQUATORIAL GUINEA / CEIBA 67 350,0002002 VOPAK ENOCFUJAIRAH LTD. UNITED ARAB EMIRATES /FUJAIRAH25 175,0002001 UNOCAL THAILAND / BIG OIL FIELD 74 120,0002000 WOODSIDE ENERGYLTD.AUSTRALIA / LEGENDRE 49 90,000 - 120,0001999 GREATER NILEPETROLEUMOPERATING COMPANYSUDAN / MUGLAD BASINDEVELOPMENT54 40,000 – 300,0001998 GEORGIAN PIPELINECOMPANYGEORGIA / CHIRAK 50 60,000 – 150,0001998 ENRON INDIA / DABHOL POWER PLANT 19 60,000 1997 APACHE ENERGY AUSTRALIA / STAG 46 150,0001997 VOLTA RIVERAUTHORITYGHANA / TAKORADI 30 40,0001996 FRED. OLSEN /SOEKORSOUTH AFRICA /SOEKOR E-BT118 128,0001996 OLEODUCTO /CENTRAL S.A.COLOMBIA / COVENAS 28.8 50,000 – 160,0001995 UNOCAL THAILAND / ERAWAN 67 150,0001993 TEXACO ANGOLA / BLOCK 2 35 175,0001993 CORPOVEN (PDVSA) VENEZUELA /JOSE ORIMULSION28 45,000 – 250,0001992 CHEVRON NIUGINI PAPUA NEW GUINEA / KUTUBU 27 300,0001989 MARATHONPETROLEUMAUSTRALIA / TALISMAN 80 70,0001986 OCCIDENTALCOLOMBIACOLOMBIA / COVENAS 25 60,000 - 120,000 1985 KODECO / PERTAMINA INDONESIA / MADURA 28 120,000 1984 MOBIL INDONESIA/ARUN 59 40,000 - 280,000 1983 ELF GABON GABON / MAYUMBA 30 30,000 - 100,0001980 ELF SEREPCA /SHELL OIL CAMEROON /KOLE – RIO DE REY30 250,0001980 ELF GABON / GULF OIL GABON / MAYUMBA 30 70,000 Calm Buoy systems (Deepwater)2014 Total E&P Angola CRAVO, LIRIO, ORQUIDEA andVIOLETA (CLOV) oil fields locatedoffshore in Angola (Block 17)1260 140,000 - 350,000Calm Buoy systems (Turntable Buoys)2008 KUWAIT OIL COMPANY(KOC)KUWAIT OIL COMPANY (KOC)TERMINAL25-30 300,0002008 KUWAIT OIL COMPANY(KOC)KUWAIT OIL COMPANY (KOC)TERMINAL25-30 300,0002005 SHELL NIGERIA BONNY TERMINAL, NIGERIA 36 350,0002003 ZUEITINA OILCOMPANYLIBYA/MARSA AL BREGA 32 275.0002002 TOTAL FINA ELF E&PCONGOCONGO / DJENO 35 340,0001996 BRUNEI SHELLPETROLEUMBRUNEI 25 20,000 - 350,0001995 SHELL SARAWAKBERHADMALAYSIA /MLNG-2 PLANT20 100,000 - 350,0001993 ONGC INDIA / NEELAM 57 147,0001991 SHELL EASTERNPETROLEUMSINGAPORE /PULAU BUKOM35 150,000 - 350,0001988 SHELL GABON / GAMBA 23 50,000 - 150,000 1986 SHELL NIGERIA / BONNY 28 35,000 - 350,000CALM Buoy Wishbone systems for Permanent Mooring1986 OCCIDENTAL /ECOPETROLCOLOMBIA / COVENAS 35 390,0001985 MONTEDISON ITALY / MILA 50 70,000 1983 AMOCO GABON / INGUESSI 30 230,0001982 PHILIPPINES CITIESSERVICEPHILIPPINES / NIDO 73 55,000CALRAM Buoy systems for Permanent Mooring1995 HAMILTON OIL LIVERPOOL BAY / DOUGLAS 30 116,500 1982 PHILLIPS PETROLEUM IVORY COAST / ESPOIR 87 240,0001981 UNION OIL OFTHAILANDSOUTH CHINA SEA / ERAWAN 68 85,000Conventional Buoy Mooring (CBM) systems2012 ONGC MumbaiHigh 75 2,5002004 CPTP, S.A. CANICAL LPG TERMINAL,MADEIRA20 30,0002002 SHUWEIHAT POWERCOMPANYSHUWEIIHAT/JEBEL DHANA,UAE10 5,0001999 SHELL TERMINALLANKASRI LANKA / COLOMBO 15 20,0001994 ONGC INDIA / BOMBAY HIGH 74 2,500 1989 ONGC INDIA / BOMBAY HIGH 68 2,500 1987/1988 ONGC INDIA / BOMBAY HIGH SOUTH 60 2,500 Tower Mooring systems2008LUKOIL RUSSIA, CASPIAN SEAYURI KORCHAGIN FIELD22 30,0002009 CONOCOPHILLIPS PENGLAI FIELD, BOHAI BAY,CHINA27300,0002005 EXXON NEFTEGASLIMITEDSAKHALIN ISLAND 45 110,0001996 TEXACO / ANGOLA LOMBO FIELD, OFFSHOREANGOLA37,5 270,0001985 SOVEREIGN OIL & GAS,DAVY OFFSHORE /NORTH SEAEMERALD FIELD, NORTHERNNORTH SEA150 200,0001982 HUDBAY OIL / MALACCASTRAIT, MALAYSIASUMATRA, INDONESIA 23 140,000Swivel Stacks2010 EMAS OFFSHORECONSTRUCTION ANDPRODUCTION PTE LTD(EOCP)BLOCK 12W IN VIETNAM 95.6 185,0002010 SAIPEM S.P.A. AQUILA FIELD 815 112,000 2010 SAIPEM S.P.A. LIVORNO FIELD 112 80,000。

第４４卷第７期２０２４年４月生态学报ＡＣＴＡＥＣＯＬＯＧＩＣＡＳＩＮＩＣＡＶｏｌ．４４，Ｎｏ．７Ａｐｒ．，２０２４基金项目：国家自然科学基金项目（３２０７１８４５）；甘肃省科技计划资助（２３ＪＲＲＡ５７２）；内蒙古自治区科技重大专项（２０２１ＺＤ００１５）；甘肃省科技计划资助（２３ＪＲＲＡ６７１）收稿日期：２０２３⁃０５⁃２０；㊀㊀网络出版日期：２０２４⁃０１⁃１２∗通讯作者Ｃｏｒｒｅｓｐｏｎｄｉｎｇａｕｔｈｏｒ．Ｅ⁃ｍａｉｌ：ｌｉｙｌ＠ｌｚｂ．ａｃ．ｃｎＤＯＩ：１０．２０１０３／ｊ．ｓｔｘｂ．２０２３０５２０１０６５程莉，李玉霖，宁志英，杨红玲，詹瑾，姚博．木本植物应对干旱胁迫的响应机制：基于水力学性状视角．生态学报，２０２４，４４（７）：２６８８⁃２７０５．ＣｈｅｎｇＬ，ＬｉＹＬ，ＮｉｎｇＺＹ，ＹａｎｇＨＬ，ＺｈａｎＪ，ＹａｏＢ．Ｒｅｓｐｏｎｓｅｍｅｃｈａｎｉｓｍｓｏｆｗｏｏｄｙｐｌａｎｔｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓ：ａｒｅｖｉｅｗｂａｓｅｄｏｎｐｌａｎｔｈｙｄｒａｕｌｉｃｔｒａｉｔｓ．ＡｃｔａＥｃｏｌｏｇｉｃａＳｉｎｉｃａ，２０２４，４４（７）：２６８８⁃２７０５．木本植物应对干旱胁迫的响应机制：基于水力学性状视角程㊀莉１，２，李玉霖１，２，３，∗，宁志英１，２，杨红玲１，２，詹㊀瑾１，２，姚㊀博１，２１中国科学院西北生态环境资源研究院，兰州㊀７３００００２中国科学院大学，北京㊀１０００４９３中国科学院西北生态环境资源研究院奈曼沙漠化研究站，通辽㊀０２８３００摘要：干旱最显著的影响表现在区域尺度的森林死亡事件中，可以在短时间内杀死数百万棵树木㊂鉴于未来极端干旱事件的频率和强度可能随温度的升高而增加，迫切需要明确树木对干旱胁迫的响应对策以及衰退死亡机理，揭示木本植物在干旱环境中存活和死亡的生理机制，了解树木在未来气候下的适应机制，提高预测树木对干旱反应的准确性㊂在常用植物功能性状的基础上，重点纳入与植物水分运输能力及耐旱性相关的水力学性状，系统总结了：１）植物木质部水分运输的物理机制；２）植物应对干旱胁迫的水力响应过程：３）干旱胁迫下木本植物水分利用对策；以及４）干旱胁迫下木本植物衰退／死亡机理㊂最后，提出３个尚待解决的主要问题：１）加强纳入水力性状阐明植物对干旱胁迫的响应和调节机制；２）加强从全株植物的角度考虑植物不同组织性状间的关系；３）深入探究树木干旱致死机理㊂关键词：木本植物；干旱胁迫；水力性状；水分运输策略；干旱致死机理Ｒｅｓｐｏｎｓｅｍｅｃｈａｎｉｓｍｓｏｆｗｏｏｄｙｐｌａｎｔｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓ：ａｒｅｖｉｅｗｂａｓｅｄｏｎｐｌａｎｔｈｙｄｒａｕｌｉｃｔｒａｉｔｓＣＨＥＮＧＬｉ１，２，ＬＩＹｕｌｉｎ１，２，３，∗，ＮＩＮＧＺｈｉｙｉｎｇ１，２，ＹＡＮＧＨｏｎｇｌｉｎｇ１，２，ＺＨＡＮＪｉｎ１，２，ＹＡＯＢｏ１，２１ＮｏｒｔｈｗｅｓｔＩｎｓｔｉｔｕｔｅｏｆＥｃｏ⁃ＥｎｖｉｒｏｎｍｅｎｔａｎｄＲｅｓｏｕｒｃｅｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｌａｎｚｈｏｕ７３００００，Ｃｈｉｎａ２ＵｎｉｖｅｒｓｉｔｙｏｆＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００４９，Ｃｈｉｎａ３ＮａｉｍａｎＤｅｓｅｒｔｉｆｉｃａｔｉｏｎＲｅｓｅａｒｃｈＳｔａｔｉｏｎ，ＮｏｒｔｈｗｅｓｔＩｎｓｔｉｔｕｔｅｏｆＥｃｏ⁃ＥｎｖｉｒｏｎｍｅｎｔａｎｄＲｅｓｏｕｒｃｅｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｔｏｎｇｌｉａｏ０２８３００，ＣｈｉｎａＡｂｓｔｒａｃｔ：Ｔｈｅｍｏｓｔｎｏｔａｂｌｅｅｆｆｅｃｔｓｏｆｄｒｏｕｇｈｔａｒｅｍａｎｉｆｅｓｔｅｄｉｎｒｅｇｉｏｎａｌ⁃ｓｃａｌｅｆｏｒｅｓｔｍｏｒｔａｌｉｔｙｅｖｅｎｔｓ，ｗｈｉｃｈｃａｎｋｉｌｌｍｉｌｌｉｏｎｓｏｆｔｒｅｅｓｉｎａｓｈｏｒｔｔｉｍｅ，ｆｕｒｔｈｅｒａｆｆｅｃｔｉｎｇｒｅｇｉｏｎａｌｃｌｉｍａｔｅａｎｄｅｃｏｓｙｓｔｅｍｓｔｒｕｃｔｕｒｅａｎｄｆｕｎｃｔｉｏｎ．Ｇｉｖｅｎｔｈａｔｔｈｅｆｒｅｑｕｅｎｃｙａｎｄｉｎｔｅｎｓｉｔｙｏｆｅｘｔｒｅｍｅｄｒｏｕｇｈｔｅｖｅｎｔｓｉｎｔｈｅｆｕｔｕｒｅｍａｙｉｎｃｒｅａｓｅｗｉｔｈｉｎｃｒｅａｓｉｎｇｔｅｍｐｅｒａｔｕｒｅ，ｉｔｉｓｕｒｇｅｎｔｔｏｃｌａｒｉｆｙｔｈｅｒｅｓｐｏｎｓｅｓｔｒａｔｅｇｉｅｓｏｆｔｒｅｅｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓａｎｄｔｈｅｍｅｃｈａｎｉｓｍｓｏｆｔｈｅｉｒｓｕｒｖｉｖａｌａｎｄｄｅａｔｈ，ｒｅｖｅａｌｔｈｅｐｈｙｓｉｏｌｏｇｉｃａｌｍｅｃｈａｎｉｓｍｏｆｗｏｏｄｙｐｌａｎｔｓｉｎａｒｉｄｅｎｖｉｒｏｎｍｅｎｔ，ｕｎｄｅｒｓｔａｎｄｔｈｅａｄａｐｔａｔｉｏｎｍｅｃｈａｎｉｓｍｏｆｔｒｅｅｓｉｎｆｕｔｕｒｅｃｌｉｍａｔｅｓ，ａｎｄｉｍｐｒｏｖｅｔｈｅａｃｃｕｒａｃｙｏｆｐｒｅｄｉｃｔｉｎｇｔｈｅｒｅｓｐｏｎｓｅｏｆｔｒｅｅｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓ．Ｐｌａｎｔｆｕｎｃｔｉｏｎａｌｔｒａｉｔｓｒｅｆｅｒｔｏｔｈｅｍｏｒｐｈｏｌｏｇｉｃａｌ，ｐｈｙｓｉｏｌｏｇｉｃａｌ，ｏｒｐｈｅｎｏｌｏｇｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｐｌａｎｔｓａｔｔｈｅｉｎｄｉｖｉｄｕａｌｌｅｖｅｌ，ｗｈｉｃｈｉｎｄｉｒｅｃｔｌｙａｆｆｅｃｔｔｈｅｐｅｒｆｏｒｍａｎｃｅｏｆｐｌａｎｔｓｂｙｄｉｒｅｃｔｌｙａｆｆｅｃｔｉｎｇｔｈｅｇｒｏｗｔｈ，ｓｕｒｖｉｖａｌｏｒｒｅｐｒｏｄｕｃｔｉｏｎｏｆｐｌａｎｔｓ，ａｎｄａｔｔｈｅｓａｍｅｔｉｍｅｒｅｆｌｅｃｔｔｈｅｌｏｎｇ⁃ｔｅｒｍａｄａｐｔａｔｉｏｎｏｆｐｌａｎｔｓｔｏｔｈｅｇｒｏｗｔｈｅｎｖｉｒｏｎｍｅｎｔ．Ｐｌａｎｔｆｕｎｃｔｉｏｎａｌｔｒａｉｔｓａｎｄｔｈｅｉｒｖａｒｉａｔｉｏｎｒｅｇｕｌａｔｉｏｎｓｃａｎｂｅｕｓｅｄｔｏｅｘｐｌａｉｎｔｈｅａｄａｐｔｉｖｅｍｅｃｈａｎｉｓｍａｎｄｆｕｎｃｔｉｏｎａｌｏｐｔｉｍｉｚａｔｉｏｎｍｅｃｈａｎｉｓｍｏｆｐｌａｎｔｓｔｏｔｈｅｅｎｖｉｒｏｎｍｅｎｔ，ａｎｄｈｅｌｐｔｏｐｒｅｄｉｃｔｔｈｅｒｅｓｐｏｎｓｅｏｆｔｒｅｅｓｔｏｄｒｏｕｇｈｔ．Ｃｏｍｐａｒｅｄｗｉｔｈｃｏｍｍｏｎｌｙｕｓｅｄｐｌａｎｔｆｕｎｃｔｉｏｎａｌｔｒａｉｔｓ，ｈｙｄｒａｕｌｉｃｔｒａｉｔｓｍａｙｂｅｔｔｅｒｄｅｓｃｒｉｂｅｔｈｅｒｅｓｐｏｎｓｅｏｆｔｒｅｅｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓ．Ｏｎｔｈｅｂａｓｉｓｏｆｃｏｍｍｏｎｐｌａｎｔｆｕｎｃｔｉｏｎａｌｔｒａｉｔｓ，ｗｅｉｎｃｒｅａｓｅｄｔｈｅｈｙｄｒａｕｌｉｃｔｒａｉｔｓｗｈｉｃｈａｒｅｒｅｌａｔｅｄｔｏｗａｔｅｒｔｒａｎｓｐｏｒｔｃａｐａｃｉｔｙａｎｄｄｒｏｕｇｈｔｔｏｌｅｒａｎｃｅａｎｄｓｙｓｔｅｍａｔｉｃａｌｌｙｓｕｍｍａｒｉｚｅｄ：１）ｔｈｅｐｈｙｓｉｃａｌｍｅｃｈａｎｉｓｍｏｆｌｏｎｇ⁃ｄｉｓｔａｎｃｅｗａｔｅｒｔｒａｎｓｐｏｒｔｉｎｘｙｌｅｍ；２）ｐｈａｓｅｓｏｆｄｒｏｕｇｈｔｓｔｒｅｓｓａｎｄｔｈｅｒｅｓｐｏｎｓｅｏｆｐｌａｎｔｓ；３）ｐｌａｓｔｉｃｉｔｙｉｎｐｌａｎｔｆｕｎｃｔｉｏｎａｌｔｒａｉｔｓａｎｄｗａｔｅｒｒｅｇｕｌａｔｉｏｎｓｔｒａｔｅｇｉｅｓ：Ｉｓｏｈｙｄｒｉｃｒｅｇｕｌａｔｉｏｎｓｔｒａｔｅｇｙａｎｄａｎｉｓｏｈｙｄｒｉｃｒｅｇｕｌａｔｉｏｎｓｔｒａｔｅｇｙ，ｘｙｌｅｍｅｆｆｉｃｉｅｎｃｙ⁃ｓａｆｅｔｙｔｒａｄｅ⁃ｏｆｆｓｔｒａｔｅｇｙ，ｃｏｎｓｅｒｖａｔｉｖｅｗａｔｅｒｕｓｅｓｔｒａｔｅｇｙａｎｄｒｉｓｋ⁃ｔａｋｉｎｇｗａｔｅｒｕｓｅｓｔｒａｔｅｇｙ；ａｎｄ４）ｍｅｃｈａｎｉｓｍｓｏｆｄｒｏｕｇｈｔ⁃ｒｅｌａｔｅｄｍｏｒｔａｌｉｔｙ：ｈｙｄｒａｕｌｉｃｆａｉｌｕｒｅｈｙｐｏｔｈｅｓｉｓ，ｃａｒｂｏｎｓｔａｒｖａｔｉｏｎｈｙｐｏｔｈｅｓｉｓａｎｄｂｉｏｔｉｃａｇｅｎｔｓｈｙｐｏｔｈｅｓｉｓ．Ｆｉｎａｌｌｙ，ｔｈｒｅｅｍａｉｎｐｒｏｂｌｅｍｓｗｅｒｅｐｕｔｆｏｒｗａｒｄｔｏｂｅｓｏｌｖｅｄ：１）ｓｔｒｅｎｇｔｈｅｎｉｎｇｔｈｅｉｎｃｌｕｓｉｏｎｏｆｈｙｄｒａｕｌｉｃｔｒａｉｔｓｔｏｃｌａｒｉｆｙｔｈｅｒｅｓｐｏｎｓｅａｎｄｒｅｇｕｌａｔｉｏｎｍｅｃｈａｎｉｓｍｏｆｐｌａｎｔｓｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓ，ｕｎｄｅｒｓｔａｎｄｉｎｇａｎｄｐｒｅｄｉｃｔｉｎｇｐｌａｎｔｓｕｒｖｉｖａｌ，ｇｒｏｗｔｈ，ｄｉｓｔｒｉｂｕｔｉｏｎａｎｄｄｅａｔｈｉｎｔｈｅｃｏｎｔｅｘｔｏｆｇｌｏｂａｌｃｈａｎｇｅ．２）ｓｔｒｅｎｇｔｈｅｎｉｎｇｔｈｅｃｏｎｓｉｄｅｒａｔｉｏｎｏｆｔｈｅｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｄｉｆｆｅｒｅｎｔｐｌａｎｔｔｉｓｓｕｅｔｒａｉｔｓｆｒｏｍｔｈｅｐｅｒｓｐｅｃｔｉｖｅｏｆｔｈｅｗｈｏｌｅｐｌａｎｔ，ｒｅｖｅａｌｉｎｇｔｈｅｄｉｓｔｒｉｂｕｔｉｏｎｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｐｌａｎｔｓｉｎｔｈｅｅｃｏｓｙｓｔｅｍ，ａｎｄｐｒｅｄｉｃｔｉｎｇｃｏｍｍｕｎｉｔｙｃｏｍｐｏｓｉｔｉｏｎ；３）ｔｈｅｐｒｅｃｉｓｅｐｈｙｓｉｏｌｏｇｉｃａｌｍｅｃｈａｎｉｓｍｂｅｈｉｎｄｔｒｅｅｄｅａｔｈｉｓｓｔｉｌｌｕｎｃｌｅａｒ，ｆｕｔｕｒｅｓｔｕｄｉｅｓｎｅｅｄｔｏｆｕｒｔｈｅｒｅｘｐｌｏｒｅｔｈｅｍｅｃｈａｎｉｓｍｓｏｆｄｒｏｕｇｈｔ⁃ｒｅｌａｔｅｄｍｏｒｔａｌｉｔｙ．ＫｅｙＷｏｒｄｓ：ｗｏｏｄｙｐｌａｎｔｓ；ｄｒｏｕｇｈｔｓｔｒｅｓｓ；ｈｙｄｒａｕｌｉｃｔｒａｉｔｓ；ｗａｔｅｒｒｅｇｕｌａｔｉｏｎｓｔｒａｔｅｇｉｅｓ；ｄｒｏｕｇｈｔ⁃ｒｅｌａｔｅｄｍｏｒｔａｌｉｔｙｍｅｃｈａｎｉｓｍｓ㊀自工业革命以来，不断增强的人类活动导致了全球变暖［１ ２］㊂联合国政府间气候变化专门委员会（ＩＰＣＣ）评估报告表明，２０１１ ２０２０年全球地表温度比１８５０ １９００年高出１．１ħ，预计在２０２１ ２０４０年全球升温或将达到１．５ħ㊂随着气温上升，未来干旱肯定会恶化（当自然干旱发生时，它们会来的更快，强度更大）［３］㊂较高的温度通常会导致更大的蒸散，与温度较低时相比，土壤和植物会更快的干燥［４］㊂这种 全球变化型干旱 已经对生态系统产生了严重影响，比如大量树木死亡［５ ６］㊂区域尺度上的树木死亡事件改变了地表反照率以及地表⁃大气能量和潜热交换，对区域气候产生反馈［７］；广泛的树木死亡事件有能力在十年以下的时间尺度内从根本上改变区域尺度的景观，对生态系统结构和功能产生重大影响［８］㊂在此背景下，我们必须提高预测树木对干旱反应的准确性，以了解树木在未来气候制度下的适应能力［９］㊂植物功能性状是指植物在个体水平上的形态㊁生理或物候特征，它们通过直接影响植物的生长㊁存活或繁殖，从而间接影响植物的性能［１０ １１］，同时反映植物对生长环境的长期适应［１２］㊂植物功能性状有助于预测树木对干旱的响应［１２ １３］㊂近３０多年来，科研人员常使用植物功能性状及其变异规律来解释植物对环境的适应机制和功能优化机制㊂然而，随着研究的深入，人们逐步发现自然界生长的植物均是通过多个功能性状共同来完成其适应或功能优化，或者说任何一种功能均是通过多种功能性状来协同实现㊂准确量化这些多性状间的权衡和依赖关系，有助于我们更好地揭示植物的生境适应策略㊂然而，研究发现：１）常用植物功能性状的变异性与降水梯度并不一致，例如平均年降水量（Ｍｅａｎａｎｎｕａｌｐｒｅｃｉｐｉｔａｔｉｏｎ，ＭＡＰ）对全球尺度上自然生物群系比叶面积（Ｓｐｅｃｉｆｉｃｌｅａｆａｒｅａ，ＳＬＡ）变异的解释率不到１％；２）常用植物功能性状与干旱引起的树木死亡率的跨物种模式仅存在微弱的相关性，例如纳入ＳＬＡ和木材密度（Ｗｏｏｄｄｅｎｓｉｔｙ，ＷＤ）时，模型对物种死亡率的解释率从只考虑干旱的３０％增加到３７％［１４］㊂相比之下，水力性状可能更好地描述树木对干旱胁迫的响应㊂近年来发现反映植物水分运输能力或植物耐旱性的水力性状如叶片的最大导水率（Ｋｍａｘ）㊁膨压消失点叶水势（Ψｔｌｐ）㊁水力安全边际（Ｈｙｄｒａｕｌｉｃｓａｆｅｔｙｍａｒｇｉｎ，ＨＳＭ）等与降水梯度高度吻合［１５ １７］㊂因此纳入水力性状阐明植物对干旱的响应和调节机制，对于理解和预测全球变化背景下植物生存㊁生长㊁分布以及死亡有着重要意义㊂鉴于未来极端干旱事件的频率和强度可能随温度的升高而增加，迫切需要更好地了解植物对干旱胁迫的应对和调节机制以及不同植物的干旱致死机制，本文重点阐述了：１）植物木质部水分运输的物理机制；２）干旱胁迫下植物的水力响应过程；３）植物水分利用策略的多样性；以及４）植物干旱致死机理㊂９８６２㊀７期㊀㊀㊀程莉㊀等：木本植物应对干旱胁迫的响应机制：基于水力学性状视角㊀１㊀植物体内的水分传输与所有维管植物一样，木本植物通过一个复杂的中空死亡细胞（导管或管胞）管道系统，即木质部，将水分从土壤输送到叶片来防止干燥损伤［９］㊂植物木质部长距离水分运输是保证植物体内水分平衡㊁叶片气孔运动㊁光合作用以及其它各种代谢活动的主要纽带，被称为 植物生理学的支柱 ［１８］㊂综述植物体内木质部长距离水分运输过程，特别是了解防止植物蒸腾速率（Ｅ）超过临界速率（Ｅｃｒｉｔ）的结构和生理机制，有助于理解植物发生水力失败和碳饥饿的风险：１）临界蒸腾速率会导致与水力失败和共质体失败相关的木质部水势阈值（Ψｃｒｉｔ）的发生；２）此外，避免Ｅｃｒｉｔ（关闭气孔）对光合作用的影响以及随后对碳水化合物储备的影响对理解碳饥饿至关重要［１９ ２０］㊂为了维持组织的水合和光合作用，植物必须补充蒸腾作用损失的水分［８］㊂内聚力⁃张力假说（Ｃ⁃Ｔ理论）认为，蒸腾拉力是水分沿木质部上升的主要驱动力，叶面的蒸腾拉力将土壤中的水分通过植物木质部长距离运输提升到冠层并扩散到大气中［８，２１ ２２］，这样从根系到叶片的水就能补充蒸腾作用损失的水分［２３］㊂其中，蒸腾拉力（Ｅ）可以通过土壤⁃植物⁃大气水力连续体的稳态公式明确描述［８］：Ｅ＝Ｋ１（Ψｓ－Ψｌｅａｆ－ｈρｗｇ）式中，Ｅ为叶片蒸腾拉力，Ｋ１为叶片水力导度，Ψｓ是土壤水势，Ψｌｅａｆ是叶水势，ｈρｗｇ是高度为ｈ，密度为ρｗ的水柱的重力拉力㊂当Ｅ为０时，Ψｌｅａｆ＝Ψｓ（图１Ａ，ａ点）㊂随着Ｅ的增加，当Ｋ１保持不变时，导管并未发生空穴化，植物体内的张力差（Ψｓ－Ψｌｅａｆ）与Ｅ成正比，Ψｌｅａｆ逐渐下降（图１左，虚线ａ ｂ）㊂然而气种假说表明：木质部导管中的水柱在张力作用下处于亚稳定状态，导管中的亚稳态液流所承受的张力随Ｅ的增加而增加，此时空气经由木质部导管壁上的纹孔膜进入导管，导管开始发生空穴化，空穴化的发展逐渐加重木质部导管栓塞程度，Ｋ１逐渐下降㊂当Ｅ每增加一个单位时，由于Ｋ１的下降，会导致Ψｌｅａｆ的下降逐渐增大（图１左，实线ａ ｃ）㊂当Ｅ超过Ｅｃｒｉｔ时，木质部水势（Ψ）超过Ψｃｒｉｔ，则会发生水力失败㊂在干旱胁迫发生时，干旱降低了根区的Ψｓ，植物在Ｅ较低时便会发生水力失败（图１右，将实线ａ ｃ和实线ｄ ｅ进行比较）㊂在昼夜尺度上，植物通过关闭气孔保持Ｅ低于Ｅｃｒｉｔ（植物通过降低气孔导度（Ｇｓ）来响应增加的Ｅ［２４］，气孔闭合程度与导致栓塞的Ψｃｒｉｔ有关［２５］）㊂减少Ｇｓ的好处是减少水分损失，但他的代价是减少二氧化碳（ＣＯ２）从大气扩散到羧基化位点，从而限制光合作用对ＣＯ２的吸收［２０］，这种水分流失和ＣＯ２吸收之间的平衡可能会在干旱期间导致植物出现生存㊁水力衰竭和碳饥饿三种结果㊂图１㊀基于达西定律模型求解的蒸腾拉力（Ｅ）与叶水势（Ψｌｅａｆ）的变化Ｆｉｇ．１㊀Ｔｈｅｔｒａｎｓｐｉｒａｔｉｏｎｒａｔｅ（Ｅ）ｖｅｒｓｕｓｌｅａｆｗａｔｅｒｐｏｔｅｎｔｉａｌ（Ψｌｅａｆ）ｉｓｂａｓｅｄｏｎｔｈｅｍｏｄｅｌｓｏｌｕｔｉｏｎｏｆＤａｒｃｙᶄｓｌａｗΨｓ是土壤水势；Ｅｃｒｉｔ是最大蒸腾速率，取决于Ψｓ；Ψｃｒｉｔ是Ｅｃｒｉｔ处的Ψｌｅａｆ，也是允许水分吸收的最低Ψｓ２㊀植物应对干旱胁迫的水力响应过程植物应对干旱胁迫的响应过程主要分为两个阶段：１）干旱胁迫开始到气孔闭合期间；２）气孔闭合到木质０９６２㊀生㊀态㊀学㊀报㊀㊀㊀４４卷㊀部完全栓塞期间［２６］㊂在干旱期间，降水减少导致土壤湿度下降，这往往伴随着更高的温度和增加的大气蒸发需求，这些因素结合在一起引起植物的水分胁迫，导致植物Ψｘ下降（木质部水柱所受张力增加），因此植物关闭气孔以限制水分流失和延缓Ψｘ的下降㊂最近研究表明，尽管气孔关闭会造成一系列负面影响，但气孔仍旧会在木质部水势达到明显的气穴化形成阈值（气孔导度损失８８％对应的水势值，ｔｈｅｗａｔｅｒｐｏｔｅｎｔｉａｌａｔ８８％ｌｏｓｓｏｆｓｔｏｍａｔａｌｃｏｎｄｕｃｔａｎｃｅ，Ｐｇｓ８８）之前关闭［２６ ２８］㊂气孔关闭后，Ψｘ随着水分通过气孔渗漏［２９］以及表皮和树皮等其他组织损失而继续缓慢下降，植物通过释放内部储存水来缓冲Ψｘ的下降［３０］㊂与此同时，植物整个水力途径的水力导度通过一系列生物物理和生理机制而下降，比如叶脉的可逆塌缩［３１］㊁细胞膜水通道蛋白调节［３２］和细根皮层腔隙的形成［３３］等㊂这一阶段的失水速率通常比气孔完全打开时低１００ １０００倍［２９］㊂如果持续干旱，水势持续下降最终达到一个临界阈值（水力导度损失５０％对应的水势值，ｔｈｅｗａｔｅｒｐｏｔｅｎｔｉａｌａｔ５０％ｌｏｓｓｏｆｈｙｄｒａｕｌｉｃｃｏｎｄｕｃｔａｎｃｅ，Ｐ５０）时，栓塞开始在木质部中扩散［３４ ３５］，这一过程发生在包括植物根茎叶在内的整个水力系统中［３６ ３７］㊂由于栓塞大大减少了向冠层的水分输送，这种水力功能障碍导致了分支斑块性死亡和冠层叶面积显著减少［３８］㊂随着栓塞逐渐遍布整个输水网络，造成植物水力系统不可逆的损伤（水力导度损失８０％对应的水势值，ｔｈｅｗａｔｅｒｐｏｔｅｎｔｉａｌａｔ８８％ｌｏｓｓｏｆｈｙｄｒａｕｌｉｃｃｏｎｄｕｃｔａｎｃｅ，Ｐ８８），最终导致整株植株死亡㊂图２㊀植物对干旱胁迫的水力响应过程Ｆｉｇ．２㊀Ｐｈａｓｅｏｆｄｒｏｕｇｈｔｒｅｓｐｏｎｓｅｔｏｄｒｏｕｇｈｔｓｔｒｅｓｓｉｎｐｌａｎｔｓ随干旱胁迫增加，虚线代表气孔和表皮导度变化趋势，实线代表木质部水力导度损失率；Ｐｇｓ８８代表气孔关闭时的水势；Ｐ５０和Ｐ８８分别代表水力导度下降５０％和８８％的水势３㊀植物水分运输策略的多样性植物功能性状对植物的建立㊁存活㊁生长和繁殖有很大影响，可以很好地表征植物的生长策略［３９］㊂然而，在哪些性状可以用来评估生态耐旱性方面，我们的知识仍然有限㊂３．１㊀衡量植物抗旱性的性状３．１．１㊀压力⁃容积曲线（Ｐｒｅｓｓｕｒｅ⁃ｖｏｌｕｍｅｃｕｒｖｅ，简称Ｐ⁃Ｖ曲线）基于Ｐ⁃Ｖ曲线计算得到的参数（如膨压消失点叶水势（Ψｔｌｐ）㊁质壁分离时的相对含水量（ＲＷＣｔｌｐ）㊁饱和含水时的叶渗透势（π０）和细胞体积弹性模量（ε））在机制上均与耐旱性有关［４０ ４１］㊂其中，Ψｔｌｐ代表了引起萎蔫的叶片和土壤的干燥程度［４０］，被认为是最直接量化植物耐旱性的 更高级别 的性状［４２ ４３］㊂植物会改变其他Ｐ⁃Ｖ参数：１）渗透调节：积累溶质（减少π０）；２）质外体调节：通过将更多的水重新分配到细胞壁外部来减少共质体水分（增加ａｆ）；３）弹性调节：增加细胞壁的弹性（减少ε）以达到足够负的Ψｔｌｐ值［４１ ４３］，提高他们的耐１９６２㊀７期㊀㊀㊀程莉㊀等：木本植物应对干旱胁迫的响应机制：基于水力学性状视角㊀２９６２㊀生㊀态㊀学㊀报㊀㊀㊀４４卷㊀旱性㊂然而，由于这些参数通常是同时调整的，因此他们在影响Ψｔｌｐ方面的相对重要性仍然存在争议㊂前人的研究表明，Ψｔｌｐ与干旱指数呈显著正相关，湿润地区的生物群系比干旱区的生物群系具有更小的负值，这支持了膨压消失点叶水势在木本生物群系尺度上反映耐旱性的观点㊂尽管大多数人认为负值较大的Ψｔｌｐ有利于耐旱性，但也有人提出了相反的观点，认为负值较小的Ψｔｌｐ是有益的㊂当Ψｌｅａｆ下降时，负值较小的Ψｔｌｐ使叶片迅速失去膨压并关闭气孔，从而保持较高的ＲＷＣｔｌｐ㊂ＲＷＣｔｌｐ，也被认为是植物耐旱性的重要衡量标准㊂尽管大多数研究认为更负的Ψｔｌｐ有利于耐旱，一些研究则认为维持细胞水合比维持膨压更重要，因为脱水会导致细胞收缩，细胞壁结构损伤以及由于高离子浓度而产生的潜在渗透压，最终破坏代谢过程㊂除此之外，细胞总相对含水量低于７５％时会严重抑制ＡＴＰ，ＲＵＢＰ和蛋白质的产生［４４］㊂Ψｔｌｐ和ＲＷＣｔｌｐ作为耐旱性预测因子的重要性经常受到争议，但没有得到解决㊂一个最近的ｍｅｔａ分析表明Ψｔｌｐ而不是ＲＷＣｔｌｐ驱动物种与栖息地水分供应的关系［４１］㊂３．１．２㊀木质部栓塞脆弱性曲线（Ｖｕｌｎｅｒａｂｉｌｉｔｙｃｕｒｖｅｓ，简称ＶＣｓ）木质部栓塞抗性是决定植物抗旱性的最重要性状之一，也是解释近年来干旱导致植物死亡的重要性状之一［４５］㊂木质部栓塞抗性通常由ＶＣｓ决定，该曲线描述了当Ψｘ降低时，水力导度丧失百分比（Ｐｒｅｃｅｎｔｌｏｓｓｏｆｃｏｎｄｕｃｔｉｖｉｔｙ，ＰＬＣ）如何增加㊂ＶＣｓ可以提供有关特定植物干旱响应的有价值的信息，并已被用于量化植物抗旱性和生态适应性㊂例如，Ｐ５０或Ｐ８８以及水力安全范围被广泛用于量化抗旱性和水力失败的风险［４６］㊂大量研究表明，当Ψｘ降到Ｐ５０或Ｐ８８以下后，Ψｘ很小的变化将引起水分传导速率大幅下降，树木也因此面临严重栓塞及死亡风险㊂Ｐ５０是最常用的栓塞抗性指标㊂Ｌａｍｙ等对地中海松树的５１３种基因型的研究发现，气候差异明显的不同种群其Ｐ５０的遗传和表型变异均有限，Ｐ５０可能是松树固有特征［４５］㊂但是关于栓塞脆弱性的遗传变异和表型可塑性的研究仅限于少数物种，仍需进一步的研究来确定这一结论是否在所有树种中适用㊂物种水平上，对栓塞抗性在木本种中种间变异的ｍｅｔａ分析表明，不同树种木质部栓塞脆弱性存在巨大差异，植物木质部栓塞脆弱性与其生长环境的年平均降水量和干旱程度相关，来自干燥气候的物种比来自湿润气候的物种具有更大的Ｐ５０值，对干旱的忍耐力越强［４７ ４８］㊂然而在群落水平上，在较干燥的栖息地，植物脆弱性的变化往往很大，这表明脆弱性和干旱在某些情况下是解耦的［４９］㊂这种解耦是因为一些物种所使用的水分胁迫规避策略，如深根系植物或干旱落叶，这些策略使得它们在干旱时期保持较高的Ψｘ［９］㊂具有系统发生学差异的植物，其致死的水势临界点（即木质部导水性不能再恢复）与Ｐ５０或Ｐ８８的关系有所差异㊂裸子植物中的水势临界点与Ｐ５０具有很大正相关性，但被子植物的水势临界点却与Ｐ８８有更高的相关度［９］㊂水力安全范围有２种计算方式：１）ＨＳＭ：树种木质部最低水势（Ψｍｉｎ）与栓塞抗性（Ｐ５０或Ｐ８８）的差值（即Ψｍｉｎ－Ｐ５０或Ψｍｉｎ－Ｐ８８），是预测树木干旱死亡率的关键指标［５０］㊂ＨＳＭ值越小，说明树种面临水力失败的风险越大，反之树种面临水力失败的风险越小［５１］㊂然而，Ｃｈｏａｔ等针对全球８１个地点２２６种森林的研究结果发现，７０％的森林在应对干旱胁迫时的ＨＳＭ很窄（约＜１ＭＰａ），安全边际在很大程度上与年降水量无关，森林对干旱的脆弱性存在全球趋同：所有森林生物群落无论当前的降雨环境如何，都同样容易遭受水力失败［４８］㊂因为Ψｍｉｎ集成了与环境相关的植物结构（例如，生根深度）和生理（例如，气孔行为）性状的许多重要方面，在不同森林类型中发现的狭窄水力安全边际为植物生态学提供了一个重要视角，这表明植物的水力策略是根据其环境进行微调的，允许最大限度的碳获得，但在干旱期间将植物暴露在水力失败的风险中［９］㊂这也表明了一种普遍存在的 有风险 的策略，即植物对环境的快速变化做出反应的生理潜力有限［９］㊂这加剧了气候变化下极端干旱事件增加所构成的威胁［９］㊂２）气孔安全边际（Ｓｔｏｍａｔａｌｓａｆｅｍａｒｇｉｎ，ＳＳＭ）：气孔闭合时的水势（Ｐｇｓ８８）与抗栓塞能力（Ｐ５０或Ｐ８８）的差值（即Ｐｇｓ８８－Ｐ５０或Ｐｇｓ８８－Ｐ８８），用来反映树种的气孔调控策略［５２］，更直接地将气孔对水势的响应和木质部栓塞抗性结合起来㊂正的ＳＳＭ表明气孔关闭发生在茎严重栓塞之前，而负的ＳＳＭ表明气孔关闭发生在栓塞之后；ＳＳＭ宽的物种的耐旱时间更长㊂有明确证据表明，等水和非等水植物的部分死亡和完全死亡与水力失败有关，这进一步凸显了气孔调节和木质部栓塞抗性之间协调的重要性㊂总的来说，气孔安全边际随着栓塞抗性的增加而持续增加，并且气孔安全边际与水力安全边际相关［５３］㊂最重要的是，将气孔调节策略与木质部水力策略相结合有助于更全面地表达植物对干旱的适应［５４］㊂３．１．３㊀非结构性碳水化合物（ＮＳＣ）ＮＳＣ包括淀粉和可溶性糖［５５ ５６］，在树木的抗旱性中发挥重要作用［５７］㊂淀粉是一种长期的碳储存分子，它以一种紧凑的㊁不溶性的形式存在，允许植物在高光合速率的情况下储存碳水化合物㊂可溶性糖为植物提供能量和底物，同时也可充当中间代谢产物㊁信号分子或渗透物㊂植物通过光合作用将ＣＯ２固定为碳水化合物，然后用于呼吸㊁防御㊁生长㊁繁殖或在光合作用无法发生时（如夜间㊁休眠季节或环境压力时期）为植物提供能量储备［５８］㊂在干旱胁迫下，ＮＳＣ扮演着两种角色［５９］，缓冲了植物的碳供应不足［６０ ６１］：１）作为 碳饥饿 的缓冲㊂在 碳饥饿 过程中，光合作用受到干旱胁迫，植物缓慢地消耗他们储存的碳水化合物直到死亡［８］㊂因此，生活在炎热和干燥气候中的植物比生活在潮湿气候中的植物分配更多的碳储存，作为应对干旱胁迫的保守缓冲［６２］㊂２）作为渗透缓冲剂㊂当水分胁迫激活淀粉降解酶时，植物可以将不溶性淀粉转化回可溶性糖［６３］㊂这种从淀粉到糖的转化可以降低植物的渗透势，从而在干旱期间维持细胞膨压［６４ ６５］㊂因此，有人认为在干燥环境中进化或生长的植物将保持较高的ＮＳＣ储存量，并保持更大比例的可溶性糖储存，以防止细胞失水，保持细胞稳定，在干旱条件下生存更长时间［４１，６６ ６８］㊂３．１．４㊀结构性状结构性状可以很好地反映不同树种面对干旱胁迫时的适应能力㊂比如，叶片厚度（Ｌｅａｆｔｈｉｃｋｎｅｓｓ，ＬＴ）与植物获取㊁利用资源的策略紧密相关㊂具有较高ＬＴ的植物可以增强蓄水能力，避免环境胁迫造成伤害㊂叶干物质含量（Ｌｅａｆｄｒｙｍａｔｔｅｒｃｏｎｔｅｎｔ，ＬＤＭＣ）常用干重和鲜重的比值来表示，干旱地区的植物ＬＤＭＣ也较高，对环境胁迫有较强的抗性［６９］㊂比叶重（Ｌｅａｆｍａｓｓｐｅｒｕｎｉｔａｒｅａ，ＬＭＡ）和叶密度（Ｌｅａｆｄｅｎｓｉｔｙ，ＬＤ）是表示干旱容忍能力的重要叶片功能性状，因为ＬＭＡ较高和ＬＤ较高表明细胞壁较厚或者较密，从而能够较大程度地防止由于叶水势下降引起的变型诱导的损坏㊂ＬＭＡ常用叶片单位面积的干物质量来表示［７０］㊂ＬＭＡ高的植物因其较强的碳同化能力能够更好地生长㊂干旱地区的植物通过提高比叶重来提高植物固持资源（碳㊁氮）的效率，从而提高竞争力㊂ＬＤ反映叶片的紧实程度及植物对外界干旱环境的忍耐能力㊂具有较高ＬＤ的植物通常适应于干旱的生境㊂通常ＬＤ高，则叶片细胞小且细胞壁较厚，能够高效积累渗透物质同时减少水分损失，从而减弱水分可利用性低对叶片造成的破坏㊂胡伯尔值（ＡＬ：ＡＳ）与ＷＤ都是物种对不同水分可利用环境进行水力调节的重要性状㊂ＡＬ：ＡＳ表征枝条对叶片的供水能力，反映蒸腾叶面积与茎输导供水之间的权衡［７１ ７２］㊂低ＡＬ：ＡＳ可以避免蒸腾过程过度失水，促进叶片水平供水以适应干旱条件，降低水力紊乱的风险㊂ＷＤ常用植物对单位体积木材投资的生物量来表示，反应植物机械支撑㊁水分运输和生长速率［７３］㊂低ＷＤ意味着储水能力较高，有利于木质部再充水而修复栓塞；高ＷＤ意味着较厚的导管壁或较丰富的机械组织，结构紧密，相应的导管面积较小㊂在干旱胁迫的环境中，植物通常具有较高的ＷＤ，保护木质部避免空穴化［７２］㊂根系与土壤环境直接接触，负责吸收养分和水分，但由于其藏匿于地下，根系性状成为了植物对干旱响应的一个重要但被忽视的预测因子［７４］㊂有关根系性状对干旱反应的数据仅限于少数几种植物［７４］㊂因此，关于植物根性状响应策略的结论似乎很特殊，或者年代太久远［７４］㊂例如，有研究报告称，一些植物种因干旱而产生更细的根，具有高比根长（Ｓｐｅｃｉｆｉｃｒｏｏｔｌｅｎｇｔｈ，ＳＲＬ）和比根表面积（Ｓｐｅｃｉｆｉｃｒｏｏｔｓｕｒｆａｃｅａｒｅａ，ＳＲＳＡ），这一策略被解释为以低投资改善水资源获取［７５］㊂相比之下，其他研究报告称，植物种产生的根更粗，ＳＲＬ和ＳＲＳＡ较低，这已被证明可以降低水力失败的风险［７６］㊂更粗的根与通过真菌营养获得高养分和高水分有关［７７ ７８］，并与由于储存非结构性碳水化合物而产生的渗透调节有关［７９］㊂植物性状有助于预测树木对干旱的响应［７３］㊂相比于常用功能性状，现在已经出现了一套经过充分研究的与耐旱性机制相关的水力性状（表１），被寄予厚望用于预测植物对干旱胁迫的响应，这代表了未来研究的方向［９］㊂３９６２㊀７期㊀㊀㊀程莉㊀等：木本植物应对干旱胁迫的响应机制：基于水力学性状视角㊀表１㊀与树木耐旱性相关的植物水力性状列表Ｔａｂｌｅ１㊀Ｌｉｓｔｏｆｈｙｄｒａｕｌｉｃｔｒａｉｔｓ（ｐｈｙｓｉｏｌｏｇｉｃａｌ，ｍｏｒｐｈｏｌｏｇｉｃａｌ，ａｎｄａｎａｔｏｍｉｃａｌ）ａｓｓｏｃｉａｔｅｄｗｉｔｈｄｒｏｕｇｈｔｔｏｌｅｒａｎｃｅｉｎｔｒｅｅｓ性状Ｔｒａｉｔ性状描述Ｔｒａｉｔｄｅｓｃｒｉｐｔｉｏｎ参考文献Ｒｅｆｅｒｅｎｃｅｓ叶片Ｌｅａｖｅｓ气孔响应Ｓｔｏｍａｔａｌｒｅｓｐｏｎｓｅ气孔闭合速率和敏感性对ＶＰＤ和叶片水势变化［８０ ８７］膨压消失点和渗透调节Ｔｕｒｇｏｒｌｏｓｓｐｏｉｎｔ＆ｏｓｍｏｔｉｃｒｅｇｕｌａｔｉｏｎ叶片叶肉细胞失去膨压和叶片枯萎的水势，以及叶片叶肉细胞渗透含量的适应性调节［４１，４３，８８ ９８］最小气孔导度Ｍｉｎｉｍｕｍｓｔｏｍａｔａｌｃｏｎｄｕｃｔａｎｃｅ当气孔处于最小孔径时，叶片角质层的水分损失率［９９ １０１］木质部外通路Ｅｘｔｒａｘｙｌａｒｙｐａｔｈｗａｙｓ液体和蒸汽通过叶肉和支持组织的阻力变化［１０２ １０４］叶脱落Ｌｅａｆｓｈｅｄｄｉｎｇ在干旱期间通过叶片脱落减少叶面积可以减缓干燥速度，减轻水分对剩余叶片的压力［８７，１０５ １０６］气孔解剖结构Ｓｔｏｍａｔａｌａｎａｔｏｍｙ气孔的形状㊁大小和分布，影响失水相关的叶片生理性状［４２，１０７］根系Ｒｏｏｔｓ皮层空腔形成Ｃｏｒｔｉｃａｌｌａｃｕｎａｅｆｏｒｍａｔｉｏｎ根皮层细胞解体，使维管组织从表皮及周围干燥土壤分离［３３，１０８ １０９］细根损失Ｆｉｎｅｒｏｏｔｌｏｓｓ细根脱落，减少根系与土壤接触的总表面积，重新平衡根枝比［３３，１０８ １１１］根系深度Ｒｏｏｔｉｎｇｄｅｐｔｈ深层根系生长，获得更稳定的水源［１１２ １１８］组织性状Ｔｒａｉｔｓａｍｏｎｇｔｉｓｓｕｅｓ栓塞脆弱性Ｖｕｌｎｅｒａｂｉｌｉｔｙｔｏｃａｖｉｔａｔｉｏｎ木质部汁液的负压导致木质部最大水力导度损失５０％或８８％㊂如，裸子植物的生理临界点（Ｐ５０）；被子植物的生理临界点（Ｐ８８）［４７ ４８，１００，１１９ １３８］水容Ｃａｐａｃｉｔａｎｃｅ在木质部周围组织中储存的水分，可以缓冲导致空穴化事件的木质部汁液负液压［３０，１１３，１３９ １４１］细胞膜通透性Ｃｅｌｌｍｅｍｂｒａｎｅｐｅｒｍｅａｂｉｌｉｔｙ水通道蛋白的活性可以改变细胞膜的通透性，导致跨膜通路的水力导度降低［３２，１０３，１４２ １４３］木质部解剖性状Ｘｙｌｅｍａｎａｔｏｍｉｃａｌｔｒａｉｔｓ木质部导管尺寸㊁数量和连通性Ｘｙｌｅｍｃｏｎｄｕｉｔ木质部导管（管胞和导管）的直径㊁长度和连通性影响最大水力导度和空穴化脆弱性㊂［１３２，１４４ １４５］纹孔膜孔隙度／厚度Ｐｉｔｍｅｍｂｒａｎｅｐｏｒｏｓｉｔｙ／ｔｈｉｃｋｎｅｓｓ纹孔膜解剖结构决定了木质部导管之间的空气传播阈值，并影响水力导度和空穴化脆弱性㊂［１２１ １２２，１３１，１４６ １４７］木材密度Ｗｏｏｄｄｅｎｓｉｔｙ木材密度由木质部解剖性状决定，并与许多生理性状相关㊂［２８，１２７，１４８］连接性Ｓｅｃｔｏｒｉａｌｉｔｙ维管组织的空间分离，防止栓塞在分支间扩散［１４９ １５４］㊀㊀ＶＰＤ：饱和水汽压差Ｖａｐｏｒｐｒｅｓｓｕｒｅｄｅｆｉｃｉｔ３．２㊀植物水分利用策略鉴于植物在异质环境中争夺空间㊁阳光㊁水和养分的策略多种多样，任何单一植物功能性状均不足以表征植物在干旱胁迫下的生存力，常需结合一系列形态功能性状㊁生理功能性状㊁生物化学功能性状来阐明植物的水分调节对策及机制，进一步揭示植物对气候变化的响应和适应［１５５］㊂３．２．１㊀等水和非等水调节策略１９３６年，Ｂｅｒｇｅｒ提出等水／非等水概念，基于叶片水势或者蒸腾来描述植物昼夜水分调节关系㊂在昼夜转换间，等水植物会在正午来临时，及时关闭气孔，维持较高的正午叶片水势㊂而非等水植物气孔则持续张开，保持水碳交换，故而正午叶片水势较低㊂近期，研究者将等水／非等水概念用于长期干旱条件下的水分管理［８６］㊂即随着土壤水势的持续降低，等水植物的叶片水势会保持较高水平，然后缓慢降低，而非等水植物的叶片水势会持续降低㊂等水植物的叶片蒸腾随着土壤变干而迅速降低，而非等水植物则先缓慢降低而后加快４９６２㊀生㊀态㊀学㊀报㊀㊀㊀４４卷㊀。