Study On The Hydrochemistry Character In The Natural Korean Pine Forest Ecosystem

In the last few years, with gradually deepening on the ecological environment protection consciousness and further recognition on the role of forest in water purification, the relationships between forest and water quality become the important content of forest ecology research and hydrology research. Taking the Liangshui National Nature Reserve as study area, and the primitive Korean pine forest as study object, the chemistry characteristics of the precipitation, the stream water, the seasonal snow cover and snowmelt runoff and element budgets of precipitation input-runoff output in the Nature Reserve were studied by the position research and comparison analysis in order to understanding the variation of element contents in the different state water. The purpose is to discover the role of forest ecosystem in water purification in virtue of the regular variation of element in water, and provide basic information and scientific foundation for the effective and rational management and utilization of water resource and forest resource, and for the influence of human activities on forest hydrological effect. The mainly results are as follows:(1) From November 2006 to October 2007, the total precipitation is 550.1mm, the pH value is 5.85, the conductivity is 17.1μS/cm,and the order of ions concentration is HCO₃^-> SO₄^2-> Ca²⁺> NO₃^-> TN > Cl^-> NH₄⁺> K⁺> Na⁺> Mg²⁺ > TP > Fe > Mn in precipitation, furthermore all the measured content show certain seasonal dynamic.(2) The results show that the stream water of each watershed in reserve is weak acidic or neutral, Ca²⁺ is the most abundant cation, in the case of anions,HCO₃^- presents the highest concentration, and all ions show seasonal variation. The expansion of manmade forest and secondary forest in researched watersheds result in the increase of the soluble matter in the stream by the comparison experiment, and the purification function are different between the forest stream and the marsh stream.(3) The main anions and cations content from the precipitation input and runoff output are 98.37 kg/hm²Â·a and 172.25kg/hm²Â·a,respectively. All main ions are net loss except Cl^-, NH₄⁺-N,NO₃^--N,TN, TP and Mn are net accumulation, but Fe is net loss.(4) The order of snow cover thickness in different forest type during winter is secondary birch forest > glade > larch plantation forests > primitive Korean pine forest > manmade Korean pine forest > spruce-fir forest, and the snow cover thickness in the primitive Korean pine forest with different canopy density decrease with the increase of canopy density. The ions concentration in snow cover of the primitive Korean pine forest, the spruce-fir forest, and the manmade Korean pine forest are higher due to evergreen and strong adsorption capacity on dry deposition. The maximum concentrations of all ions in snow cover of the primitive Korean pine forest with different canopy density are detected at a canopy density arranged from 0.5 to 0.7.(5) The runoff during the snowmelt period reaches its peak at late April, and the duration is about 10 days. The ions concentrations show the regular variations during the snowmelt period. The discharge is negatively correlated with the pH value,conductivity,the concentration of Na⁺,Ca²⁺,Mg²⁺,K⁺ and HCO₃^-,and positively correlated with Cl^-, SO₄^2-,NH₄⁺-N,NO₃^--N,TN and TP,respectively.