Circannual rhythm of young stands structure of Phyllostachys iridescens and Phyllostachys propinqua in red soil area

Key words: 
• Phyllostachys iridescens /
• Phyllostachys propinqua /
• stand structure /
• bamboo stand culture /
• red soil

Abstract: Aimed at vegetation resume and entironment improve , exert potential of production in red soil area , and objected to Phyllostachys iridescens and Phyllostachys propinqua .Through five years orientation study on the changing rule of young bamboo stands structure .The results showed that the ability of scourging and sprouting of Phyllostachys iridescens and Phyllostachys propinqua are strong , the ratio of new bamboo stand culms is highness , the changing of bamboo stand culms year by year is notability , reach to respectively 2 430 and 2 970 individual plants each hectare second year , and put into production third year after forestation .Average diameter in breast height (DBH)of new culm reach to 3.54 cm and 3.21 cm respectively at third year after forestation .Bamboo stand culms and DBH reach to level of fertility at fifth year after forestation .Bamboo rhizome of the two species mainly distributing the range of above 20 cm thick soil , length of rhizome exceed 10 m per spuare meter third year after forestation , and average diameter of rhizome are 1.75 cm and 1.32 cm respectively , amount of sprout is increasing along with forestation years , third year up to 119.4 % and 202.9 % than first year after forestation .The paper indicated the two bamboo species can be extend at large scale in red soil with characteristics of strong ecoadaptability and good economic profit .Standard seedling is one and two year age with 2.5 cm and 3.5 cm DBH, and first forestation density is 900 and 1 500 individual plants each heatare .Soil management and bamboo stands structure adjustment are mainly measures to young bamboo stands for ahead of put into production and higher profit . [ Ch , 6 tab .12 ref .]