Abstract:

Naturalness assessment was a basic work for natural forest management and it also could be used to propose reasonable measures for forestation. This study was carried out in Qinling mountain where most forests were natural secondary forests and our objective was to assess naturalness of the main forest types in this region. The data were collected from 35 stand plots and 105 soil samples. On this basis, through sensitivity analysis of 30 indexes which describes the community characteristics, 17 indexes were filtered out and used to establish an assessment index system. Integrated indexes were analyzed with the analytic hierarchy process (AHP) to build a model for assessing the naturalness. The results showed that: The integrated indexes of naturalness of Tsuga chinensis secondary forest, Quercus aliena var . acuteserrata secondary forest, Pinus armandii secondary forest, Cephalotaxus sinensis secondary forest, Pinus armandii plantation, Pinus tabulaeformis plantation, Larix principis-rupprechtii plantation were 0.98, 0.90, 0.78, 0.56, 0.39, 0.35, 0.01 and their naturalness classifications were 1, 1, 2, 3, 4, 4, 5 respectively. Tsuga chinensis secondary forest, Quercus aliena var . acuteserrata secondary forest were Near -natural forest, other forests were semi-natural forest, Far from-natural forest, Near-plantation and plantation, respectively. The order of naturalness was climax community>transition succession community>pioneer community>native seedling plantation>exotic seedling plantation. The assessment results fitted the actual situation well, which indicated the index system had good performance in this region. According to the naturalness of different forest types, some corresponding measures of management were proposed.

Key words: Qinling moutains, forest types, index system, naturalness, assessment