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| Nutrient cycling in Quercus varlabilis plantations of different ages classes in hilly region of Taihang Mountain |
| Zhao Yong1,Wang Pengfei2,Fan Wei3,Zhu Yanfeng1 |
| 1.Henan Agricultural University,450002;2.Institute of Building Material Industry,450002;3.The Henan Academy of Forest Sciences,450003:Zhengzhou,China |
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Abstract In order to analyze the characteristic of the vegetation restoration process,the characteristic of the content,accumulation,distribution and nutrient cycling of three nutrient elements(N、P、Ca) in Quercus variabilis plantations were studied taking the communities of the sample sites analysis in hilly region of Taihang Mountain as investigation objectors.The results showed that: 1)the nutrient element content in different tree organs is different,the content of three nutrient elements in leaves were the highest,but the lowest in stems.The descending order of nutrient elements contents is as following: Ca,N,P.2)the content of organic matter and N,P in soil have significantly increased with the plantations ages of Quercus varlabilis,it is concluded that the soil fertility increased with the vegetation restoration process.3)the total accumulation amount of nutrient elements ranged from 2 764.58 to 3 689.38 kg/hm2 in the different age stands,annual nutrient elements storage were from 89.88 to 138.17 kg/(hm2·a).The return amount of different elements were 229.80,262.06 and 246.63 kg/(hm2·a) for 20,30 and 40 a stands of Quercus variabilis respectively.It shows a increasing trend of the total accumulation amount with stand age.The amount of absorption and return of different elements increased with the stand age at first,and then decreased.The descending order of amount of elements storage,absorbance,return,and accumulation is Ca,N,P. 4) The nutrient use coefficient was decreased with stand age.However,both nutrient cycling coefficient and turnover time were increased with stand age.Ca has the longest turnover period of 12.73-16.19 years but the lowest utilization coefficient.
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Received: 07 August 2008
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