The Geographic Variation Of Plant Polyphenols And Coupling Relationship With Environmental Factors Of Pinus Bungeana

Pinus bungeana is an important afforestation tree specie in China, is also one of the important species of northern mountain vegetation restoration, has the very high ecological value, economic value and ornamental value. It is widely distributed in shaanxi, shanxi, gansu,henan, sichuan, hunan and hubei provinces, more than a scattered block distribution,distribution of the natural ecological environment destroyed, leads to the deterioration of forest growth, so it is necessary to further strengthen the study of P. bungeana and protection work. In this paper, we study in P. bungeana needles, litter and soil geographical variation of plant polyphenols and its correlation with needles, litter and soil carbon(C), nitrogen(N) and phosphorus(P), the coupling relationship of P. bungeana plant polyphenols in needle-litter-soil and the coupling relationship with plant polyphenols and environmental factors were discussed, for our understanding of the nutrient cycling of natural P. bungeana germplasm resources protection and sustainable utilization is of great importance.The conclusions were as follows:(1) The plant ployphenols concentrations in the different area of natural P. bungeana(needle, litter, soil) were determined. The study area of P. bungeana needle total polyphenols(TP) concentrations were 19.07~41.00 mg g-1, mean 30.40 mg g-1, range of litter TP concentrations were 1.84~8.72 mg g-1, mean 5.01 mg g-1, range of soil TP concentrations were 0.50~1.06 mg g-1, the average was 0.79 mg g-1. Within the scope of this research area,needle TP concentrations increases with the increase of latitude, its shows the significant positive correlation; litter TP concentrations have no obvious regularity in latitude gradient;soil TP concentrations decreases with the increase of latitude, show the significant negative correlation. TP in needle and soil have no obvious regularity in longitude gradient, litter TP concentrations decreases with the increase of longitude.(2) In P. bungeana needles, litter and soil TP correlation analysis between carbon(C),nitrogen(N), phosphorus(P), the results show that there exist significant negatively correlate relationships between needle TP and soil C, soil C: P, soil N: P values; litter TP were significant positively correlation with needle N, but with the soil C: P, soil N: P values were significant negatively; soil TP were significantly positive correlation with soil N, soil C, soil P and soil N: P.(3) Huanglong mountain 8-70 years of P. bungeana needles polyphenol content from high to low order as: 8 years > 15 years> 20 years > 35 years > 30 years in 70 > 40 years >50years. Needle polyphenol content range is 25.67 to 38.86 mg g- 1, 8 years of sapling needles polyphenol content variability and the smallest, most shows that the old section of P.bungeana needles polyphenol content tends to a stable value, the existence of the plant polyphenols more effectively protect and promote the growth of young trees. Maijishan mountain 4 plant needles polyphenol content from high to low order as: P. armandii(40.65 mg g-1) > P. orientalis(36.65 mg g-1) >P. tabuliformis(27.38 mg g-1) >P. bungeana(26.82 mg g- 1).(4) By the methods of Pearson analysis, stepwise regression, principal component analysis and path analysis,we study the correlation between the plant polyphenols of P.bungeana in 15 regions and the environmental factors. Results showed that P. bungeana plant polyphenols and environmental factors have the most significant or extremely significant correlation, through the regression equation and the linear relationship can express, after fitting regression equation in significance level a = 0.05 under the condition of high precision,strong reliability and practical value. Among the test environmental factors, annual lowest temperature, annual average temperature, annual rainfall, frost-free period, soil total carbon and total phosphorus are the main factors affecting the concentration of the plant polyphenols of P. bungeana, with a contribution rate of 98.9%. Soil total phosphorus is the key factor controlling the plant polyphenols of P. bungeana, mean annual precipitation is the main decision factor, and annual extremely low temperature is the main limiting factor.