Dynamic Characteristics Of Hydro-ecological Function And Nutrient Dynamic Characteristics In Liquidamba Formosana Plantation

The hydrological processes and dynamic characteristics of the main nutrient elements carbon and nitrogen in terrestrial forest ecosystems balancing process plays an important role. Hydrological function and nutrient research has become a hot topic of social concern about the plantation ecosystem. Liquidambar the maintenance of high fertility and ecological benefits of good, excellent fast-growing deciduous broad-leaved species. Reveals Liquidambar plantation ecosystem and water circulation systems temporal variation regularity, mechanism and driving variables, we become a serious problem. In January2009to December2010, we study dynamic characteristics of Liquidamba formosana plantation ecosystem hydrology ecological function and nutrient cycling by long-term observation in Changsha. Research data of plantation vegetation and water cycle was accumulated. The purpose is to reveal the Liquidamba formosana plantation hydro-ecological function and nutrient cycling characteristics, to estimate the role of water in Liquidamba formosana plantation ecosystem conservation, reasonable and effective operation and maintenance of forest productivity. The results showed that:1、Liquidamba formosana artificial canopy interception of precipitation interception rate is mainly distributed in the range of10.7%to59.3%, the atmospheric rainfall canopy interception relationship:y=9.6893+0.1079x, P<0.01; stem-flow relationship:y=-0.0493+0.0182x, P<0.01; Rinnai rainfall correlation:y=-9.6433+0.8739x, P<0.001; canopy interception of precipitation showing obvious monthly and seasonal changes, rainfall in the summer and autumn forest within average minimum of59.4%the rainfall of up to84.5%. Stem-flow rate showed increase with the increase in the intensity of precipitation. The observed quarter average minimum value of0.94%, the highest season average value of2.4%. Same rainfall intensity, Liquidamba formosana plantation Summer Forest crown interception, reaching39.37percent, spring, fall, winter canopy interception rate of36.51%,37.75%,34.02%, showing a summer> autumn> spring> winter characteristics.2、Precipitation pH value in the range of5.7±0.2～7.0±0.2of the Rinnai rainfall pH value in the range of6.4±0.1～7.2±0.2of the changes in the pH of stem-flow fluctuations. Three precipitation average pH value descending order:the penetration of water (6.8±0.20)> precipitation (6.5±0.20)> the stem-flow (6.34±0.17). Outside the forest precipitation Ca2+element content in the highest,632.3mg/L Cu2+content of the lowest, only0.038mg/L, Rinnai rainfall of Ca2+content in the highest,11.253mg/L, representing a variety of chemical components of the total amount of34.29The%; NO3-N content accounted for3.90%; NH4+-N content of18.14%; K+content of29.27%. Pb2+content is lowest, is only0.027mg/L The sap flowing water, NH4+-N content of the highest, accounting for30.72%of the total; Pb2+content was the lowest, only0.013mg/L.3、Liquidamba formosana plantation meteoric Rinnai rainfall and the stem-flow difference between the content of each nutrient season was significantly (P<0.05), a large number of elements in the precipitation, forest rainfall and stem flow of NO3-N and NH4+-N, Ca2+, K+, SO42", Mg2+content showed low during the rainy season, dry season and high content with precipitation season showed obvious seasonal dynamics. Outside the forest precipitation seasonal variation biggest is NH4+-N, Rinnai rainfall seasonal variation biggest is K+. stem-flow in seasonal changes in amplitude and outside the forest precipitation and Rinnai rainfall is just the opposite, the largest seasonal variation PO42-. Trace elements outside the forest precipitation, throughfall, and stem-flow in different seasons input volume showed a consistent trend. Rainfall within the forest, Fe3+, Cu2+. Zn2+, Pb2+and Cd2+showed negative leaching. The Liquidamba formosana plantation ecosystem of forest within rainfall Cu2+, Fe3+, Zn2+,Pb2+and Cd2+with a certain degree of absorption, adsorption, purification function.4、Large root, root and fine root of Liquidamba formosana plantation nutrient element content of nutrient elements in the total content of the differences in significant significantly (P<0.05), large root, root and fine root of a large number of elements different season of the content of the differences in significant significantly (P<0.05). Large root, the difference between the roots and fine roots trace element contents season reached significant (P<0.05). The seasonal variation of the total content of winter> summer> spring> autumn. Liquidamba formosana Plantations differences between the vegetation total content of nutrient elements season significantly (P<0.05). The annual average of the nutrient content of the understory vegetation38.925±4.263g/kg, the difference between the total content of trace elements under vegetation season significantly (P<0.05). The annual average of the total content of nutrient elements of the understory vegetation929.125±114.537mg/kg. Understory vegetation seasonal variation of trace elements significantly (P <0.05).5、Annual average litterfall biomass of Liquidamba formosana plantation was1023.9±114.3g/m in surface litter layer thickness of0.8to2.0cm, which leaf, sprig of69.37%of the total litter weight. The annual average of the total content of the litter nutrient elements to32.480±3.537g/kg. Liquidamba formosana forest soil nutrient elements in the total content of a downward trend from a layer down to C and A layer of a large number of differences between the elements of the total content of B, C layer reaches a significant (P<0.05), the total content of the annual average of7.419±1.053g/kg, the difference between the large number of elements contained significantly (P<0.05). The annual average of the total content of the soil the B layer nutrient elements5.724±0.493g/kg. The difference between the large number of elements of the soil B layer significantly (P<0.05). The annual average of the total content of the soil the C layer nutrition elements5.623±0.484g/kg. No significant differences (P>0.05), the annual average of the total content of the three layers of soil nutrient elements1905.709±201.427mg/kg total content of trace elements in the soil layer.