Abstract:

The primary ecological effects of rehabilitation models in converting farmland to forests in eastern Liaoning mountains were continuously investigated through 6 years observation in the typical permanent plots. The results showed that intense competitions occurred among vegetations and perennial herbs, semilignified species and shrubs turned into domination after 3 years rehabilitation. Stable forest community can be formed after 6 years of artificial reforestation. Total biomass per unit area was highest in arborshrub model, especially in lignified roots and its comprehensive effect, better than any other models, though its ability of water and soil conservation was one year later than natural rehabilitation. The arbor model took the second place. Taking that in control (continuous farming plot) as 100%, average runoff in 6 years was 11.9% in arbor plot, 14.49% in arbor-shrub plot and 10.65% in natural restoring plot, and the corresponding sediment discharge was 1.95%, 0.15%, and 0.04% respectively. The microzoon system (especially insects) changed with the conversion. In comparison with the control, three rehabilitation models had relative diversified species and a complex parasitical/clinging microzoon population which has formed the chain structure preliminarily.

Key words: models of converting farmland to forest, vegetation rehabilitation, ecological effect, hilly regions in eastern Liaoning