| Casuarina equisetifolia is the most main casuarina division one of tree species, naturaldistribution in Australia, southeast Asia and the Pacific islands, now widely introduction intropical and subtropical regions, is China southeast coastal protection of the main forest treespecies. casuarina equisetifolia was introduced abroad into the southeastern coastal area since1950s, has become the important species of coast protection forest, It has played important role inpreventing wind and fixing sand,improving the ecological environment and offeringtimber.However,littoral situated at the where terrene marched with ocean,the gigantic change ofclimate here is easily result in disaster weather,typhoon,rainstorm,storm tide,drought and waterlogging raid the seashore and around area,as well as serious human interference make regionalecological condition factors such as the growth of the discussion, the coastal shelter forest systemto the sustainable development of the great influence. Generelly, coastal sand is loose, retainingwater ability is poor,low rainfall,seasonlly dry is very serious in southeastern coastal areas, wateris the one of necessary ecological factors, According to Casuarina equisetifolia plantations waterutilization.Water ecological research report is less, And artificially Casuarina equisetifoliaplantation sustainable forest management business had caused attention of scholars both at homeand abroad. Although a number of studies have suggested that both at home and abroad, sap flowin plant water physiology mechanism and characteristics of water play an important position, wehad estimated the water consumption through the fluid flow characteristics, but for sap flow in thestudy of the not mature, especially in our country. however,because Casuarina equisetifolia hasdrought resistance,resistance to poor,fight saline,wind break and sand-fixation and other biologicalcharacteristics, in addition, Casuarina equisetifolia sap flow characteristics and water consumptionhad not a lot experiments to do in our country, The biological characteristics and the use of thewater have very big concern. A thermal dissipation probe was used to measure the sap flowdynamics of Casuarina equisetifolia plantations on coastal sandy soil from March2010to January2011at chihu protection forest farm, Hui an county in fujian coastal sand. The6sample trees wereselected in different diameter; photosynthetic active radiation,air temperature,solarradiation,relative air humidity,water vapor pressure deficit,and wind speed were measured at thesame time by the weatherpak~2000.USA. this paper from Casuarina equisetifolia sap flow and environmental factors of the relationship and casuarina moisture transpiration management toprovide water management theory basis. The results showed that：1. The sapwood area of Casuarina equisetifolia and the DBH were used for an index relationship;the correlation coefficients is0.9849.2. The results showed that patterns of diurnal variation of Casuarina equisetifolia sap flow velocitywith a gentle single-peak curve on sunny,cloudy,Light rain days; peaks appear during theday;compeared with sunny day, sap flow velocity is lower peak curve on cloudy day; sap flowvelocity were similar with a gentle single-peak curve on bigger rainy day. and sap flow existwhole all night and bigger and than the day;patterns of diurnal variation of Casuarina equisetifoliasap flow velocity were Twin peaks or irregular curve,with Sharp curve on typhoon day, but therewere certain peak, which doesn't appear during the day, and appear in the night.3. From March2011to January2012, Sap flow velocity of overall change trend for"low-high-low"during monitoring in different months,Sap flow velocity of the maximum and theaverage were fluctuated during Monitoring different periods, but it is a decreasing trend ingeneral.Diurnal variation of stem sap flow velocity was similar among the different months,However, there are differences in sap flow mean starting time,mean peak time and Sap flow meandescending time among different months. But it is no obvious regularity.It have different degreesof delaying during different growing periods, in Eary stage, Sap flow velocity starting time isabout8:00～8:30; in Intermediate stage, from May to September, starting time is about7:00~7:30;in Telophase, from October to November,sap flow start time starting time is about at latest is about8:30～9:50. in Anaphase, and in the timing of reaching peaks as well as descending is about12:30and21:40, It has different degrees of delay.4. Sap flow velocity of Casuarina equisetifolia also showed non significant correlations with DBH.Bigger diameter at breast height of the sample tree sap flow velocity and DBH of small sampletree sap flow velocity are not difference,it is irregular.5. The Sap flow velocity fluctuated with one climax in sunny day, and the Sap flow velocity onthe south side of the tree was bigger than that on the north side, and its range was wide．Patterns ofdiurnal variation of the sap flow in sunny days were similar during date of Collection,except thatthere was difference in the timing of initiating and reaching peaks,but this difference is notobvious,There were positive correlations between Vs and environmental factors, air temperature,air humidity, RAD, PAR, soil temperature is not obvious. On the south and north sideof tree, the corelation coeficients being in the order Air temperature> RH> solar radiation>photosynthetic active radiation, The sap flux density(Fs) between7:00and19:30was the major inone day, and it was about90percent. the Fs on the north side of the tree was about0.13～0.68ofthat on the south side.6. when the increase of soil water content, Because of the influence of the rainfall, sap flowvelocity and the soil moisture content of different soil layer was positively related to the overalltrend during different months; when the decline of Soil moisture content, sap flow velocity and thepositively related to soil temperature in May,sapflow velocity and soil temperature was negativelycorrelated. in June and in July. Casuarina fluid flow rate soil moisture content of different soillayer was negative correlation overall trend during different months;In different months, underthe condition of soil temperature, sap flow velocity were in July with different soil layer soilmoisture content is negative correlation, this experiment results: march soil temperature and flowrate correlation negative correlation to the overall trends in May, the relevant analysis shows thatwhen0~10cm,10~20cm soil water content is plentiful,Casuarina equisetifolia sap flowvelocity and0~10cm,10to20cm soil water conten twas positively associated；20~30cm,30~40cm soil water content without obvious regularity; in June,Casuarina equisetifolia sap flowand soil water content correlation are positive and negative. the trend of the overall performancewithout regularity. In may, June, September, soil temperature was positively associated withCasuarina equisetifolia sap flow in July.7. According to the correlation analysis,The results showed that: sap flow velocity were impacteddifferent by meteorological factors during the monitoring growing season;different monitoringperiod of sap flow velocity and the meteorological factors associated intensity differences andshowed a trend of decrease. During the whole monitoring sap flow velocity were positivelycorrelated with photosynthetic active radiation(PAR), air temperature,solar radiation(RAD),watervapor pressure deficit(VPD)and wind speed (Ws),and had a negative correlation with relative airhumidity(RH).sap flow velocity with photosynthetic active radiation, solar radiation andatmospheric temperature, water vapor pressure deficit, wind speed are positively related; Andthe relative humidity was negatively correlated; However, Sap flow velocity of Casuarinaequisetifolia positively correlated with relative humidity; Wind speed was negatively correlated during Augest29th and September1th. Various meteorological factors related order size is differrnt,During the whole monitoring plays a leading role of the meteorological factors, Airtemperature,water vapour pressure,relative humidity. During the season of date of collection,Multiple linear regression equations for meteorological factors with sap flow velocity wereestablished, which all met the significance at0.01levels with F test.8. Finally,it can be used to estimate the total water consumption,daily average consumption of allsample trees during the date of collection, sample tree3and sample tree1the total waterconsumption was218t and160t, in the growing season, during July.19th～19.27th and Augest22th～Augest28th. respectively.The water consumption of different diameter at breast heightsample tree did not show big diameter at breast height high water consumption trends, and in thegrowing period of different months,6sample trees in the month of may daily average waterconsumption and daily average consumption were biggest, other months are all lower than in May,in Intermediate stage, the water consumption were biggest, followed in Earystage,inTelophase,inAnaphase, respectively. |
PDF Full Text Request