Hydro-chemical Characteristics and Metal Ions Transfer of Larix gmelinii var. principis rupprechtii Plantation in Xiaowutaishan

In 46-year Larix gmelinii var. principis-rupprechtii plantation in Xiaowutaishan, Hebei province, sample plot with 30m×40m was established to collect water sample from precipitation and redistribution processes (through-fall, stem flow, litter-through, runoff on slope ) at early, middle and later stage of growth of plantation. Determination was implemented on water quantity, pH, and mass concentrations of Ca²⁺, Mg²⁺, K⁺, Na⁺, Zn²⁺, Mn²⁺, Fe²⁺, Cu²⁺. The results showed that the mass concentrations of Mg²⁺, Mn²⁺, Na⁺, Ca²⁺, Fe²⁺ of through-fall and stem flow and that of K⁺, Na⁺, Mg²⁺, Zn²⁺, Mn²⁺ of litter-through and runoff on slope at early stage were the highest in the 3 growth stages. Ca²⁺, Mg²⁺, K⁺, Na⁺, Zn²⁺, Mn²⁺, Fe²⁺ showed leaching loss during redistribution process. At middle stage of growth, Ca²⁺, Mn²⁺, Cu ²⁺ showed leaching loss, Mg²⁺, K⁺ were adsorbed, and Na⁺, Zn²⁺, Fe²⁺ had different performances during redistribution processes. At later stage of growth, the mass concentrations of Zn²⁺ in through-fall and stem flow were the highest in the 3 growth stages. Ca²⁺, Mg²⁺, Zn^2+, Mn²⁺, Fe²⁺ showed leaching loss, and Na⁺,Cu ²⁺ were adsorbed, and the performance of K⁺ was different during redistribution processes. In the whole redistribution process, the mass concentration of Cu²⁺ was ordered by later stage>middle stage>early stage. pH of through-fall, runoff on slope at middle stage, and runoff on slope at later stage was >7, that of the left process, pH was <7. The plantation interception had nearly 95% of precipitation. The amount of metal ions interception by litter was much higher than that by canopy and total amount of soil input.