采矿迹地优势菊科植物叶片及细根氮、磷含量的季节变化

Seasonal variation of foliar and N,P contents in fine roots of three dominant composites on mining site

对首云矿业采矿迹地恢复植被中3种优势菊科植物猪毛蒿(Artemisia scoparia Waldst.et Kit.)、黄花蒿(A.annua L.)、茵陈蒿(A.capillaries Thunb.)叶片和细根氮、磷生态化学计量特征季节波动进行了研究.结果表明,3种菊科植物叶片氮、磷含量在生长季内表现为生长初期先增大后减小,5月份幼叶氮、磷含量稍低,6月达到最大值,生长旺季7-9月含量逐渐降低并达到最小值;而细根氮、磷的季节变化与叶片呈相反的趋势,即生长初期降低,生长末期逐渐增加.叶片氮/磷在生长季内表现为生长季先降低后增加,细根氮/磷初期略增加,后期与叶片氮/磷呈一致的变化.3种菊科植物叶片氮/磷含量之间存在显著的正相关关系(P<0.01);除茵陈蒿氮含量与氮/磷之间存在显著的正相关关系(P<0.01)外,猪毛蒿和黄花蒿叶片氮含量与氮/磷之间无显著相关性;3种菊科植物磷含量与氮/磷之间存在负相关关系.

We monitored the seasonal variation of N, P in foliage and fine root of three dominant com- posites, Artemisia scoparia Waldst. et Kit. , A. annua L. and . A. capillaries Thunb. in Beijing Shouyun iron ore mine, at different stages of growing season. The three composite plants have unani- mous seasonal fluctuation of foliar N and P content. The content of N and P increased in the initial stage and then decreased until the end of growth. At the initial stage, N and P content of juvenile leaf was a bit low in May, the maximum value appeared in June, N and P content decreased gradually until it reached the minimum value in terminal season, Seasonal variation of N and P content of fine root in- dicated opposite trend with variation of foliage. Namely,the content of N and P decreased at the intial stage, increased at the end of growth. Seasonal variation of N/P contents was also contrary to that of foliage N, P contents, which was high at the initial stage, then decreased following the growing boom season, then increased in terminal season gradually. The foliar content of N and P had significant positive relationship （P 〈 0.01 ） of the three dominant composites. Variation of N/P in fine roots was simi- lar to that of foliage except for the initial stage. Foliar of A capillaries Thunb. N and N/P has significant positive relationship（P 〈 0.01 ） while Artemisia scoparia Waldst. et Kit. And A annua L. have no sig- nificant relationship, P and N/P of three composites have negative relationship.