A Study On The Technology Of Helth Monitoring And Regulation Of The Forests Under Acid Deposition In Tieshanping, Chongqing

A series of studies was put into practice in Chongqing suffering from acid rains and atmospheric pollution in 2004-2005. Intensive observations of soil elements, above-ground and underground growth, needle elements and health of artifical pure stands of Pinus massoniana Lamb, were done to know their general growth condition and obtain health evaluation threshold values. A fixed position experiment was conducted to research on effects of different application amounts of lime powder on acidified forest soil on of element contents in needles and growth of Pinus massoniana Lamb, and put forward optimum chemical regulation-control method. Two pure stands of Cinnamomum camphora (L.) T.Nees & C.H.Eberm., one pure stand of Schima superba Gardn. et Champ, and one mixed stand were chosen to probe into effects of Cinnamomum camphora (L.) T.Nees & C.H.Eberm. on improvement of acidified forest soil and enhancement of forest health. In order to discern plants resistant to acid rains and atmospheric pollution, a field investigation of wide scope on plant sensitivity to acid rains and atmospheric pollution and their damage to plants was carried out. The main results were as follows:1)The relationship between defoliation percentages of dominant trees of Pinus massoniana Lamb.and chemical properties of humus and soilIn the pure stands of Pinus massoniana Lamb., in humus layer and soil layers of 0²0cm, 20⁴0cm and 40⁶0cm under dominant trees of different defoliation percentages of 0-20%, 20-40%, 40-60% and >60%, pH values were 2.99-3.06, 3.59-3.60, 3.77-3.80 and 3.75-3.80 respectively, BS values were 16.70-20.68%, 6.15-8.58%, 4.74-6.14% and 2.96-5.47% respectively, differences in contents of exchangeable K⁺, Na⁺, Ca²⁺, Mg²⁺, Al³⁺, Fe³⁺, Mn²⁺, H⁺, total N, total P and organic matter between the same layers was not obvious, and contents of Al³⁺, Fe³⁺, Mn²⁺, H⁺ and total S were high. Chemical properties in the same layers under dominant trees of different defoliation percentages were similar, pH values were very low and differences were very small, BS values were very low, soil became seriously acid, and its buffering power was very limited.2)The relationship between defoliation percentages of dominant trees of Pinus massoniana Lamb.and fine root growth, needle element contents and overground growthIn the pure stands of Pinus massoniana Lamb., all the fine root density indexes in...