Abstract. Close-to-nature management (CTNM) has been proposed as a promising
forestry management approach to improve the structure and quality of
forests, which integrates wood production and ecological service functions.
Research on the effect of CTNM on the univariate and
bivariate distribution of the spatial structure of forest stands provides a
scientific basis for the evaluation of CTNM implemented in forestry. Here,
we analyzed and compared the spatial-structure characteristics of Masson
pine (Pinus massoniana) plantations (young, middle-age, and near-mature stages) under CTNM
8 years after selective cutting and unmanaged control. We used
univariate and bivariate distribution of three spatial-structure parameters:
mingling (M), dominance (U), and uniform-angle index (W). Results showed that
the effect of CTNM on spatial structure was more remarkable in middle-aged
and near-mature Masson pine forests compared with the young forest. CTNM
significantly improved mingling degree and promoted the horizontal
distribution, thereby changing from a cluster to a random distribution.
Moreover, CTNM improved the proportion of trees with a high mixing degree
and random distribution and the proportion of trees having a micro-structure
of random distribution with a high degree of mixture and dominance with a
high degree of mixture in middle-aged and near-mature Masson pine forest.
Overall, the implementation of CTNM 8 years ago showed a positive effect
on the improvement of the spatial structure of Masson pine forest, but the
present spatial structure is suboptimal. Further implementation of CTNM to
adjust the mingling and uniform-angle index is necessary, and CTNM according
to this method of frequency distribution of stand structure parameters can
improve the success of forest management.
Ectomycorrhizal fungi inoculation alleviates simulated acid rain effects on soil ammonia oxidizers and denitrifiers in Masson pine forest
