低温域湿地植物根际氮转化强度

Nitrogen transformation intensity in wetland plant rhizosphere area at low temperature

在低温条件下(0～15℃),对菖蒲、芦苇、香蒲等10种湿地植物根际土壤的氮转化强度进行对比分析.结果表明,湿地植物根际氨化、反硝化作用强度随温度下降而逐渐降低,硝化作用强度在10℃左右出现大幅下降;低温域植物根际反硝化作用强度明显高于硝化作用强度;植物种类对根际土壤氨化、硝化作用强度影响较大,其中香蒲氨化作用强度最大(0.85 mg/(kg.h))、慈姑硝化作用强度最大(0.21 mg/(kg.h));植物种类对反硝化作用强度及pH值无明显影响.通过综合评价,低温域香蒲、千屈菜、芦苇根际氮转化强度较强,可作为提高湿地冬季脱氮率的优选耐寒植物.

Nitrogen transformation intensity in rhizosphere soil of ten different wetland plants,such as acorus calamus,phragmites australis and typha orientalis,at low temperatures（0 to 15℃） are compared in this paper.The results indicated that： intensity of ammonification and denitrification decrease with decreasing temperature;nitrification intensity decrease sharply while the temperature is under 10℃;denitrification intensity is obviously higher than nitrification intensity in plants rhizosphere;the difference of plant species has great impact on ammonification and nitrification intensity;typha orientalis has the strongest ammonification which is 0.85 mg/（kg·h）,while sagittaria sagittifolia has the strongest nitrification which is 0.21mg/（kg·h）;plant species has no obvious effect on denitrification and pH in rhizosphere soil.After the comprehensive assessment,typha orientalis,lythrum salicaria and phragmites australis are selected out for nitrogen removal in wetlands at low temperature because of their stronger nitrogen transformation strength in rhizosphere soil.