Ecosystem Function Research Of Casuarina Equisetifolia Shelterforest In Fujian Coastal

Fujian coastal Casuarina equisetifolia shelterforest is the important ecological barriermaintenance coastal ecological environment. However, because of the research aboutstructure and function of coastal C. equisetifolia shelterforest ecosystem every little,theoretical basis related to the construction of the coastal shelterforest is weak, resulting in theserious lag of the coastal C. equisetifolia shelterforest construction and protection anddegradation of the coastal C. equisetifolia shelterforest. Therefore, a more complete study infujian coastal C. equisetifolia shelterforest ecological system function has importanttheoretical and practical significance on the coastal shelterforest system construction.In this paper, the application of remote sensing and GIS methods to analyze the change ofthe coastal shelter forest landscape ecological pattern in recent20years. By positioning andrandom sampling method, we has carried on the systematic research to shelterforest biologicalproductivity and carbon deposits in spatial distribution, wind prevention and sand fixation, theinfluence on evaporation and soil water balance and the effect for crop production of Pingtanand Dongshan County C. equisetifolia shelterforest, evaluating rationally of coastal C.equisetifolia shelterforest ecological function and providing a scientific basis for buildingshelterforest. In view of the present problems that C. equisetifolia shelterforest ecologicalfunction facing, shelterforest ecological function network construction scheme is put forward.The main research conclusions as follows In this paper:Through the analysis of fujian coastal shelterforest landscape pattern change in recent20years, showing that shelterforest landscape fragmentation is on the rise and landscapediversity index and evenness index decrease. Due to affected by human factor and othernatural factors, the area of C. equisetifolia and other main kinds of shelterforests are in adownward trend.Fujian coastal C. equisetifolia shelterforest biomass model, building by W=D2H, canshow the relationship between the biomass and tree height and diameter at breast height.Fujian coastal C. equisetifolia shelterforest has high biological productivity. But because ofthe different of the location and the distances from the shore, biological productivity betweentypes of shelterforests has obvious differences. Shelterforest belt productivity is more thanthat of coastal backbone shelterforest. Dongshan County C. equisetifolia shelterforestproductivity is more than Pingtan County. In general, C. equisetifolia in coastal areas in ourprovince is still the preferred shelterforest trees. According to the proportion of high and low,vegetation layer and soil layer carbon reserves in Dongshan and Pingtan County two types ofC. equisetifolia shelterforest is dongshan farmland C. equisetifolia forestbelt(277.70t/hm~2)>pingtan farmland C. equisetifolia forest belt(246.14t/hm~2)>dongshan coastal backbone C.equisetifolia shelterforest(185.34t/hm~2)>pintan coastal backbone C. equisetifoliashelterforest(153.54t/hm~2). Above analysis showed that the farmland shelterforest is higherthan the coastal backbone shelterforest and Dongshan County shelterforest is higher than thepingtan county shelterforest. In the spatial distribution of C. equisetifolia shelterforest carbondeposits, tree layer> soil layer> litter layer. Carbon content of soil layers decreased with soildepth, and there is a significant change between0~30cm soil layer. The coastal areas of Fujian C. equisetifolia shelterforest belt plays a very significant rolein wind prevention and sand fixation. Forest protection makes the wind speed after the forestreduce about25~40%on average. According to the effect of wind prevention and sandfixation, space between C. equisetifolia shelter belts is150~200m best. Research on coastalwind prevention and sand fixation backbone protection ability suggests that coastal backboneshelterforest has a great effect of wind speed, velocity droping by96.20%in400m.Shelterforest mainly through wind speed reduced makes different sand of particle size havedifferent distribution proportion and different stacking thickness in different distanceshelterforest. Considering the possible effect of protective function of wind and other factors,the most suitable width of coastal backbone shelterforest is should be600m. Therefore, wesuggests that the width of fujian coastal shelterforest stipulated by in fujian province coastalbackbone technical regulations should be revised to600m from200m.After planting C. equisetifolia, the organic matter content, soil alkaline hydrolysis N,available potassium and available phosphorus content of sandy soil increase to some extent,indicating that C. equisetifolia shelterforest improves sand soil nutrient obviously. C.equisetifolia in inshore saline area can reduce the soil salt content. But when the acidic islower than5.5, the growth of the C. equisetifolia is inhibited. This may be one of the mainreasons that the second generation forest updates the bad in C. equisetifolia artificial pureforest region. This problem needs to be studied further.The survey of damaged C. equisetifoliashelterforest ecological function shows that the damaged forest accounts for29.9%of totalforest, while the coastal backbone shelterforest area accounted for19.8%of the coastalbackbone protection forest area. Density of the damaged shelter belt dropped an average of70%, resulting in that function of the forest wind resistance reduced by41.5%.Under the influence of forest, evaporation of each point in front and back of forest beltvaries with the distance. Vaporization reduces by12~25%in60m before and200m afterforest, vaporization reduces the most obvious in40~100m back of forest belt, reaching20%.Farmland soil moisture content in the forest leeward is higher than that in forest windwardside (10~30%). But the deeper soil layer, the smaller the difference. Content of surface soilis affected by evaporation. The greater the amount of evaporation, the lower moisture content.The shelterforest has obvious role to increase crops production. Barley yield significantlyincrease during the winter, the average yield reaching about7%and grain about4.8%. Withinthe scope of the different forest protection, before the forest (north)2~7.3H, after the forest(south)2~25H are increased production areas, increasing rate up to22%. North of forest0~1H, south0~2H are reduced production areas, reducing rate up to11%. Other is theaverage production area.