Study on the Plant Biodiversity and Spatial Patterns of Broad-leaved Korean Pine Forest in Changbai Mountain
|School||Beijing Forestry University|
|Keywords||broad-leaved korean pine forest plant biodiversity season dynamics population spatial pattern stand structure|
The forest is the principal part of the terrestrial ecosystem, an important natural resource for the people to live on, which functions indispensably on the adjustment of the eco-balance. The situation is that the phenomenon of the coexistence of the small-area virgin forest and the large-area secondary forest in the region of Mount Changbai is similar to that of any other region, because of cutting and other mankind disturbance. So, how to recover the low-quality secondary forest is the stringent problem faced with the sustainable development of forest for us to solve. Therefore, the paper focuses on the difference of the organization, structure between the virgin forest and secondary forest, with the example of the change of temporal pattern and dimensional structure on the broad-leaved korean pine forest and its secondary forest. The paper also discussed the reciprocal function of niche is of great importance for the maintenance of the stability of the virgin forest. The detail is as follows:In the region of the Guangming Forest Centre of the Baihe Forest Bureau and the natural reserve of Mount Changbai, four fixed-plots have been set up with Topcon total station. The type and size of the plots is respectively as:Broad-leaved korean pine forest plot (100m×100m) Closely mature forest plot (260m × 200m ) Middle-year forest plot (260m × 200m ) Secondary mature forest plot (160m × 100m)The coordinate positioning and research of each single tree are carried out on the whole of the shrubs of the broad-leaved korean pine forest and part of the shrubs of the middle-year forest. The research of the diversity change in the growing seasons is also been performed with the sample setting of 1m × 1m of broad-leaved korean pine forest, middle-year forest and secondary mature forest.The research shows that there are vascular plants of 265 species, in which there are 47 tree species, 31 shrub species and 187 herb species.The number of tree species is 20、 29、 34 and 40 in the broad-leaved korean pine forest, closely mature forest, secondary mature forest, middle-year forest respectively. The abundance of the tree diversity of each type of forests above is consistent with that of their species. The dominance of the pioneer species is obvious in the middle-year forest. And the species in the succession layer is most abundant. The relative abundance of the dominant plant population in the future climax community is more than that in the virgin forest, while its relative dominance is less and the change of the relative frequency is minor. Fraxinus mandshurica Rupr.is one of them, all of whose indexes changes most. And the indexes of Acer mono Maxim stays most stable.The species of shrubs are 18 and 30 in the broad-leaved korean pine forest and middle-year forest respectively. The species of the shrubs under the trees, its average density and biodiversity of the middle-year forest are far higher than that of the broad-leaved korean pine forestThe species of herbs are 158, 137 and 103 under the middle-year forest, secondary mature forest and broad-leaved korean pine forest respectively. The diversity of the herb layer experiences the process from the lower class to higher class, then vice versa in the growing season. The test of the hereditary distances demonstrates that there are obvious differences of herb layer between months in the same community. The detailed figures of the difference of the hereditary distances arranged from the longest to the lowest are as follows: May and June, June and July, August and September, July and August. What’s more, the herb layers of different plots have no obvious differences in May, while with great difference in other months.The diversity of tree, shrub and herb layers is much more abundant in the types of secondary forests than that in the broad-leaved korean pine forest. The main cause is that there is some increase of the propotion of the sun plants in each of these layers in the secondary forests.Ripley’s K (d) function shows that Pinus koraiensis is in the aggregated distribution in the range of 0-13m, F. mandshurica 7-9m, Tilia mandshurica 0-47m and T. amurensis 0-7m and 9-30m.They are in the random distribution in other ranges. Quercus mongolica is in the random distribution of all the ranges. The pairs of the dominant species in the upper stratum whose relativity is minor include: T. amurensis - F. mandshurica, and Q. mongolica - P. koraiensis; The pairs that are negative association in a narrow rage include: T. amurensis - Q. mongolica, and T. amurensis - F. mandshurica; While in a wide range includes T. mandshurica - T. amurensis. The species who have close relationship with each other is more negatively associated in a wide range, and the dominant species whose ecological behavior are more close to each other shows negative association in a narrow rage. The dominant species of the crown layer demonstrate a pattern of random distribution, and the interrelationship of species is not obvious because of the polarization of the niches. A. mono shows obvious negative association in all levels of range. So does with A. mandshuricum. The two are obviously negatively associated with each other in the range from 0 to 7m. A. tegmentosum, A. pseudo-sieboldianum and A. barbinerve are in the aggregated distribution in a wider range, and they have reached the maximal aggregated intensity in the minor range. There exists narrow-ranged aggregated distribution among these species, and then many narrow-ranged patches constitute a wider-ranged aggregated distribution. The species of Q. mongolica have a wider-ranged spatial negative association each other. There is no significant relationship between the upper stratum in the crown layer and A. mono, while the upper stratum is negatively associated with A, mandshuricum obviously. There exists the interrelationship that first negative association and then random distribution in the whole in the example of the upper stratum and the lower stratum, the middle stratum and the lower stratum. The only difference lies in the range size of the interrelationship. Syringa reticulata(Blume)Hara. var.mandshurica and Corylus mandshurica only shows obvious negative association in the scale from 0 to 12m., Philadelphus schrenkii and Deutzia amurensis from 0 to 15m, C. mandshurica and P. schrenkii from 0 to 37m, and S. reticulata(Blume)Hara var.mandshurica and P. schrenkii only from 0 to 6m.The analysis of the stand neighborhood pattern demonstrates that the broad-leaved korean pine forest and its secondary forests show the aggregated distribution in a whole.The magnitude of the minglings of the middle-year forest, secondary mature forest, closely mature forest and the broad-leaved korean pine forest shows as follows : 0.54,0.63,0.64,0.53.The research shows that in the same community, the higher the level of the minglings in the upper stratum, the lower the level of the minglings in the lower stratum; the higher the level of the minglings in the species of the seed-breeding, the lower the level of the mingling the stump-breeding. When a species has the both breeding ways , the level of mingling will be higher. In the secondary forests, the level of the mingling of eh pioneer species is higher, while the dominant species of the future climax community lower. In the virgin forests, the dominant species of the upper crown layers have higher level of mingling.The analysis of the neighborhood comparison of the nearest neighborhood stand structure unit shows that in a community, the upper stratum take advantage over the lower stratum in growth, which accords with the practice; in the relatively early phase of the secondary succession, pioneer species dominate in growth, and the species of the future climax community are restrained temporarily; in the relatively middle phase, pioneer species and dominant plants of the future climax community share the advantage; in the climax community, pioneer species is first to be eliminated, while the dominant species take the sheer advantage.The research includes the analysis of the biodiversity change of the broad-leaved korean pine forest and its secondary forests, Ripley’s K (d) function of the dominant plant population and the spatial structure of the neighborhood stand structure unit. Those findings clarify quantificationally that in the secondary forests, co-existence of the same types of the pioneer species is rare, while the pioneer species take advantage in growth. Therefore, the level of mingling of the dominant species in the future climax community is low because of the cutting and the existence of the young trees, and it is alse inferior to others in growth. With the recovery of the secondary forests, the pioneer species and herbs are been eliminating, and there comes the decline in biodiversity. The dominant species of the future climax community is beginning to take the advantage in growth and its relative dominance increases. But due to "self-thinning", the level of mingling of the upper trees is growing, while the niche between the species of the same layers and the different layers gradually differentiates, the population pattern become randomly distributed and the community grows to be stable.