Coupled Study On Resource Patch And Population Distribution Of Kingdonia Uniflora On North Slope Of The Mt. Taibai

Kingdonia uniflora is one of the endangered plant species in China, distributing in a patchy pattern. Previous surveys on environment factors concerned with Kingdonia uniflora were all one-time measurements for specific sites, neglecting the spatio-temporal heterogeneity of environment factors. In this paper, Digital Imaging Technology, Geographic Information System and Digital Plant Canopy Imager were used to analyze spatio-temporal patterns of light resource patch, canopy structure, soil physical and chemical properties in forest within the Kingdonia uniflora distribution area locating on north slope of the Mt.Taibai. in China. In addition, based upon a 2 X 2 contingency table, a series of techniques including analysis of variance ratio for testing the overall association of all species, X~2-test for testing the property of the interspecific association and association indices (Ochiai, Dice, Jaccard) for showing relationship degree of the interspecific association, were used to determine and measure the interspecific association among the 136 species-pairs of Kingdonia uniflora and its 16 companion species. Aiming at providing reliable data support and theoretical basis for the protection of Kingdonia uniflora and further determining a convenient method for sunfleck dynamic research, the coupling relation of resource patch and Kingdonia uniflora population distribution pattern are expected to establish in this study, and their causes are to be explored.The results are as follows:(1) Sunfleck index was established as integrated indicator reflecting properties of sunfeck, when we studied sunfleck spatio-temporal transformation .The index could conveniently offer a composite measure containing the area, duration and irradiation intensity of sunfleck.(2) In sunfleck dynamic study, the quantity, size and sunfleck index values in the plots with Kingdonia uniflora were significantly lower than that of the plots with no Kingdonia uniflora (P<0.05).(3) Coupling relation between distribution of sunfleck and Kingdonia uniflora was researched by association analysis. The results showed that in the high, medium and low altitude, Kingdonia uniflora distribution was positively correlated with the region of lower total radiation, while negatively correlated with the region of higher total radiation. Their relationship and association degree were exactly judged by this method.(4) The differences of canopy structure between two types of plots were statistically significant. The transmitable coefficient for diffuse penetration, the transmitable coefficient for radiation penetration and the canopy gap area size of the areas with Kingdonia uniflora were lower than that of the places with no Kingdonia uniflora (P<0.05). Whenas, the leaf areas index was in reverse order. These differences showed that the influences of the forest canopy structure on the quantity, intensity, and duration of sunfleck and distribution of Kingdonia uniflora are significant.(5) In the case of small-scale, there was no significant difference between two types of samples in soil physical and chemical properties, indicating that within such small-scale scope, the soil factors may not affect the distribution of Kingdonia uniflora.(6) Interspecific association analysis showed that the overall association of all species is significantly positive. All species-pair were checked by X~2-test, in which 17 species-pair were observed to have very significant positive association at 0.01, 6 species-pair at 0.05 and 6 species-pair revealed very significant negative association at 0.01, 3 species-pair at 0.05. All species-pair were also checked by Ochiai index, majorities of species-pair were lower, and just 7 positive association species-pair overtop 0.5. These reflect the independence of species-pair. The loose interspecific association was possibly related to the development stage of communities and ecological features of species.Through analyses of light, soil factors, canopy structure and companion species, it is proposed that sunfleck is likely the dominant factor determining the Kingdonia uniflora patchy distribution on North Slope of the Mt Taibai. Meanwhile, These convenient methods were described in this paper, which application prospects will be very promising in the field of plant population biology and physiological ecology.