Abstract:

In this paper, the effects of three regeneration patterns, i.e. natural regeneration(N.R.), artificial measures promoting regeneration(A.M.P.R.) and artificial regeneration(A.R.) on stand structure, species composition, under-growth biomass and soil fertility of secondary broadleaved forests were studied. The results as followed: In 1200 m² sample plot, there are 159 species (tree 76 species) in N.R. stand, 130 species(tree 62 species) in A.M.P.R. stand and 94 species(tree 33 species) in A.R. stand. In the arbor layer, there are 14 families 28 species in N.R. stand, 12 families 26 species and 2 families 2 species in A.M.P.R. and A.R. stands respectively. The undergrowth biomass, in N.R. stand, A.M.P.R. stand and A.R.stand are 10.903 t·hm^-2, 13.893 t·hm^-2 and 6.018 t·hm^-2 respectively. Compared with the A.R. stand, the changes in N.R. and A.M.P.R.stand are showed respectively as followed: the soil bulk density of 0～20cm soil layer decreased by 12.44% and 7.89%,the capillary pore increased by 18.5% and 15.7%, the total soil porosity increased by 7.57% and 12.79%, the organic matter are increased by 4.03% and 1.50%, the total N increased by 19.02% and 29.30%, the total P(P₂O₅) increased by 63.4% and 29.2%.

Key words: Regeneration pattern, Stand composition, Soil fertility