Characteristics Of Soil Fertility And Stand Productivity Of Bamboo Forest In Dabieshan, Anhui Province

Phyllostachys pubescens is the most economical valuable bamboo species in China, with thelargest number, most extensive area and most widely used among the bamboo forests. Currently, theannual output of the Mao bamboo exceeded450million tons, which supplied large amount of rawmaterial for the development of Chinese industry and agriculture. In recent years, however, someserious problems appeared in the bamboo production, such as extensive management, unreasonablefertilization and shortened rotation for the short-term profits in some places. Consequently, thebamboo forest suffered serious damage, and finally resulting the decline of the whole bamboo forestecosystem.With the expansion of business and production scale of Mao bamboo, there has been also agradually degradation of soil fertility in the bamboo ecosystem. In order to solve the existingecological problems in the production of Mao bamboo forests, a systematic research was conductedin Huoshan of Dabieshan District, which is the main production area of bamboo in Anhui Province.The characteristics of stand productivity with relation to soil fertility was analysis. It is expected toprovide a theoretical basis and feasible measurements for the sustainable management of bambooforest.The main results obtained in this study are as follows. The mean diameter at breast height（DBH）, mean height, mean density, mean basal area and mean AGS of bamboo stand wereseparately,10.99cm,15.25m,2323#hm^-2,22.51m²hm^-2, and0.28. The number of plots with AGSless than0.3covered53.5%of the total sampling plots.The bamboo biomass partition was ordered as stem （73.46%）> twig （14.41%）> root （6.68%）>foliage （5.45%）. The slope position had a significant effect on the bamboo biomass, with a biomassof62.18t hm^-2in the foothills,43.39t hm^-2in the middle slope, and40.83t hm^-2in upper slope. Inaddition, the slope aspects also significantly influence on stand production, with an order of biomassas east (62.65t hm^-2)> west (51.69t hm^-2)> north (41.12t hm^-2)> south (39.71t hm^-2).Among all the sampling stands, total N and organic matter decreased with the soil depth. Thecontents of total P in both0¹0cm and30⁵0cm soils were larger than in the10³0cm layer. Thetotal K in the surface soil （0¹0cm） was lower than in10³0cm soil. Slope position and aspect hadclearly influence on the element abundance of bamboo forest soil. The total P, K, organic matter andavailable N on the foothills were significantly higher than on the middle and upper slopes, with anorder as foothills> middle> upper slope. However, no significant difference was found for theavailable P in soils on the different slope position.The slope aspects have different influences on the soil nutrient content. For total N and K, theorder is east> north> west> south aspects; for the organic matter, east> west> south> north. However, no significant difference was found for the available P and available N at the differentaspects.The results from the correlation analysis indicated that the mean H was significantly correlatedwith total P, K, soil organic matter, available P and available N in0¹0cm soil, among which total K,soil organic matter and available N were more significant than the other variables. The stand densitywas significantly correlated with organic matter. The mean AGS of bamboo stand was significantlycorrelated with total P, K; the mean DBH was significantly correlated with organic matter, total P, K,organic matter, available P and available N. The total biomass was significantly correlated with totalP, total K and soil organic matter.In10³0cm soil, the mean H was significantly correlated with total K, organic matter, availableN; AGS of bamboo stand was significantly correlated with is total P, K, organic matter; the meanDBH was significantly correlated with total P, K, organic matter; total biomass was significantlycorrelated with total P, K, organic matter, no significant correlation was found between the nutrientcontent and density.In30⁵0cm soil, the mean H was significantly correlated with K, organic matter, available N;stand density was significantly correlated with the nutrient content except organic matter; mean AGSof bamboo stand was significantly correlated with total P, K, organic matter; DBH was significantlycorrelated with K, organic, available N, the total biomass was significantly correlated with total P, Kand soil organic matter.In order to determine the major controls on the productivity of Mao bamboo among the soilnutrient variables measured, Principal Component Analysis （PCA） was used in the statistic analysisin this study.The PCA results indicate that in the depth of0-50cm, the first principal component is total Pand available N, and the second principal component is organic matter and pH, the third principalcomponent is available P, the fourth principal component is total N. The four components made acumulative contribution of81%in explaining the variance variation of the whole variables,suggesting that those factors are the main controls on bamboo productivity in Dabieshan district.