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| Plant nitrogen resorption characteristic and it's relation with soil factors in Xiaolangdi mountainous hilly region |
| Zhao Yong1,Fan Wei2,Fan Guoqiang1 |
| 1.Department of Environment Science,Henan Agricultural University,450002;2.Henan Academy of Forest Sciences,450003: Zhengzhou,China |
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Abstract In order to figure out the conservation strategies of plant nitrogen in different plant species in temperate zone and to find out the environmental and plants related mechanisms in regulating nitrogen resorption of these species,nitrogen concentration in mature leaves and senescing leaves and nitrogen resorption efficiency（NRE） of 21 plant species belonging to three different life-forms were studied in Xiaolangdi hilly areas,Henan Province,centre of China.The results showed that a significant positive linear correlation was found between nitrogen content in senescing and in mature leaves of all life-forms.The majority of the 21 investigated species in study sites withdrew less than 40% of nitrogen from their senescing leaves.NRE in these species ranged from 17.4% to 50.1%,with an average of 28.8%,depending upon the species and the life-form.The pattern of NRE in different life-forms followed the order of herbs>shrubs>trees.The results show that most of species examined in this study can be categorized as incomplete nitrogen resorption plants.Nitrogen concentration in mature leaves（Ng）and nitrogen concentration in senescing leaves（Ns）increased with increasing soil（organic） matter,total soil nitrogen and soil moisture.However,NRE was negative related to soil organic matter,total soil nitrogen and soil moisture,meaning that the higher soil organic matter was due to reduce plants NRE.Therefore,it is likely that plants from infertile environments may have a higher NRE than those from fertile（environment.） In disadvantage condition,such as soil infertile,the plants can adapt environmental stress by（increasing） NRE in mountainous hilly region in north china.
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Received: 20 June 2006
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