Natural Regeneration and Succession in Natural Mixed Forests in Maoershan Region, Heilongjiang Province
Soil seed banks and population structure were surveyed by the methods of stratified sampling and layered counting to better understand the regeneration and succession in broad-leaved forests in Maoershan region, Heilongjiang Province. In the seed banks, the seeds of Fraxinus mandshurica, Acer mono, Quercus mongolica and Juglans mandshurica accounted for 86.3%, 7.3% , 4.1% and 2.4% , respectively. The seed storage of F. Mandshurica and A. Mono in decomposed organic layer were significantly higher than that in undecomposed organic layer and humus layer (P<0.05). The percentage of morphologically intact seeds reduced as the depth increased in the seed banks. The seed storage of Q. Mongolica in decomposed organic layer were significantly higher than that in humus layer (P<0. 05 ) , and there was no obvious difference in seed storage between undecomposed organic layer and humus layer. An insignificant difference was observed in seed storage of J. Mandshurica in different horizons. In the seed banks, the seed storage of F. Mandshurica and A. Mono could meet the requirements for natural regeneration, while the seed storage of Q. Mongolica and J. Mandshurica appeared to limit natural regeneration. The basal area of Populus davidiana accounted for 20% of the total of the mixed forest, while that of the other species accounted for 10% respectively. The ratios of the number of F. Mandshurica and Q. Mongolica in different layers were highest in regeneration layer, followed by upper layer and succession layer; those of A. Mono exhibited regeneration layer, successive layer, and upper layer in descending order. The seedlings of F. Mandshurica, Q. Mongolica and J. Mandshurica are hard to grow into successive layers, which is one of the reasons for limiting the nature regeneration. In the future, F. Mandshurica and A. Mono will become dominant species in the natural mixed forests in Maoershan region.
NETL
NSTL
万方数据
维普
