The Nutrient Characteristics Of Phyllostachys Edulis Forest During The Growing Stage Of Spring Shool And Young Bamboo

Phyllostachys edulis is the most important economic bamboo specie, which is the most widely distribution in China and has the longest history of cultivation and utilization. In order to get the better economic benefit, the stand structure-adjusting and fertilization has been applied, and the influence of the management measures on bamboo forest productivity also has been studied mainly and thoroughly. However, the research on the dynamic changes of nutrient of bamboo forest and physiological characteristics were relatively weak, especially the law of nutrient dynamic and demand during special physiological periods is unclear, which affected the sustainable and health management of bamboo forest. Material flow and energy flow of the bamboo ecosystem ware all rapidly changed during the growing stage of spring shoot and young bamboo. In order to manage the nutrient of bamboo forest better, this paper studied nutrient characteristics of bamboo forest and the effects of nutrient regulation during the growing stage of spring shoot and young bamboo in Huangshan, Anhui Province. The main conclusions were as follows:(1) The characteristics of nutrient contents in young bamboo and mother bamboo with various ages during the growing stage of spring shoot and young bamboo:Nutrient contents in different organs of young bamboo kept decressed during the period, the nitrogen, phosphorus and potassium contents in bamboo shoot in Mid-April were30.60mg·g-1,3.37mg·g-1,48.07mg·g-1, respectively. After the young bamboo finished pumping leaf and branch in a month, they reduced to8.41mg·g-1,1.10mgg·g-1,14.44mgg·g-1, respectively. The nitrogen, phosphorus and potassium contents in rhizome and rhizome root had little change. In order to meet the nutrient demand of young bamboo, the nutrient contents in Ⅰ du, Ⅱ du, Ⅲ du bamboo changed a lot simultaneously. The nitrogen, phosphorus and potassium contents in leaf decreased significantly with the growth of bamboo shoot, which showed that the nutrient output of old bamboo increased. (2) The difference of nutrient contents in different organs of mother bamboo between the growing stage of spring shoot and young bamboo and off-year:Compared with the same bamboo forest in the same period during off-year, the nutrient contents in different organs of mother bamboo had obvious change. The nitrogen, phosphorus contents in leaf and root during bamboo forming stage were25.92mg·g-1,3.45mg·g-1and0.47mg·g-1,0.47mg·g-1, respectively, which declined by1.6%,7.8%and35.3%,6.3%with the off-year, respectively. The results showed that the mother bamboo had obvious nutrient regulation in order to meet the growth of young bamboo and the update of forest.(3) The characteristics of nutrient contents in soil during the growing stage of spring shoot and young bamboo:Nutrient contents in young bamboo rhizomephere soil were higher, and hydrolytic nitrogen, available potassium and available phosphorus contents were245.17mg·kg-1,251.08mg·kg-1,12.39mg·kg-1, which were significantly higher than that in Ⅰ du, Ⅱ du, Ⅲ du bamboo rhizomephere soil, that showed the absorbtion ability of young bamboo was low and the nutrient demand of young bamboo had to depended on mother bamboo system; the nutrient contents in mother bamboo rhizomephere soil had no difference. The metabolic of mother bamboo root was active to strongthen the absorbtion ability, and organic matter, hydrolytic nitrogen, available potassium and available phosphorus contents in mother bamboo rhizomephere soil were significantly lower than that in non-rhizomephere soil,(4) The effects of different nutrient regulation treatments during the growing stage of spring shoot and young bamboo:Fertilized Ⅰ du, Ⅱ du, Ⅲ du bamboo in different treatments, the nitrogen, potassium contents in old bamboo leaf and young bamboo had no difference after fertilized, however the phosphorus content in them after fertilized were significantly higher than that had non-fertilization. The productivity of new bamboo shoots after Fertilizing Ⅰ du bamboo was biggest and reached to8.25t·hm-2In summary, the absorbtion ability of young bamboo was low during the growing stage of spring shoot and young bamboo. In order to guarantee the growth of young bamboo, the nutrient contents in mother bamboo organs and rhizomephere soil changed obviously, and the change in Ⅰ du and Ⅱ du bamboo was particularly evident. Therefore, it is important to manage the nutrient of bamboo forest, especially the nutrient regulation of Ⅰ du and Ⅱ du bamboo.