Assessment and analysis on forest health of Pangu forest farm in Daxing'anling mountains of China

By taking the forest resources planning and design investigation data of Pangu Forest Farm in 2008, the investigation data of permanent sample plot in 2011 and the forest health assessment data with sub-compartment as the scale as the data sources, the forest health of the tested forest farm with landscape as the scale were estimated; By taking the plot types, origin and tree species composition as the forest landscape division factors, forest landscape types of the farm were divided; the sub-compartment health index, fractal dimension and landscape diversity were selected as the evaluation indexes from the aspects of landscape structure and pattern, landscape function and process; the health of forest landscape of Pangu Forest Farm was evaluated with mean square error decisionmaking comprehensive analysis method as the determination method of weight and by taking the index formula of landscape health as the evaluation model. The results show that(1) the forests of Pangu Forest Farm were mainly divided into 10 forest landscape types, including pure Betula platyphylla forest, nature pure Larix gmelinii forest, nature pure Pinus sylvestris var. mongolica forest, nature pure Picea schrenkiana var. tianschanica forest, nature pure Populus davidiana forest, nature coniferous mixed forest, nature broad-leaved mixed forest, nature conifer and broad leaf mixed forest, artificial Larix gmelinii forest, artificial conifer and broad leaf mixed forest.(2)There was no healthy forest landscape in the farm; there were3 types of sub-health forest types, accounting for 78.51% of the farm's total forest area; there were 4 types of medium-health forest landscape types, accounting for 21.03% of the total forest area and there is there was 1 type of un-health forest landscape type, accounting for 0.32% of the total forest area; the sco res of health index of forests in Pangu Forest Farm were low overall, and most landscapes were in sub-health and medium-health state.(3) The scores of health index was high in the south and low in the north overall; among the natural forests, Larix gmelinii forest had the highest score, followed by coniferous mixed forest, while the score of broad leaved mixed forest was lower than the mean level and the two artificial fo rests had the lowest scores.