氮素与水分添加对内蒙古温带典型草原生物量的影响

发布时间：2018-11-11 15:22

【摘要】：为了解大气氮沉降和降水格局改变对草原生物量的影响,在内蒙古温带典型草原开展氮、水添加控制试验.试验设置对照(CK),氮素添加(10 g m~(-2) a~(-1)),水分添加(60 mm m~(-2) a~(-1)),氮、水同时添加(N 10 g m~(-2) a~(-1)+水60 mm m~(-2) a~(-1))4种处理.经过两年试验处理,结果显示:(1)较对照处理,氮添加处理下总生物量(403.03 g/m~2)、地上生物量(279.97 g/m~2)、地下生物量(123.07 g/m~2)和禾类草地上生物量(165.35 g/m~2)均显著增加,而杂类草地上生物量变化不显著.(2)水添加较对照显著增加了地上生物量(200.93 g/m~2)、杂类草地上生物量(177.82 g/m~2),但显著降低了地下生物量(-110.39 g/m~2),而总生物量与禾类草地上生物量变化不显著.(3)氮添加处理下,水添加显著增加了地下生物量与禾类草地上生物量,但对总生物量、地上生物量、杂类草地上生物量没有显著影响.进一步分析显示,在不添加水分条件下,氮添加较对照显著增加禾类草地上生物量(107.15 g/m~2)与地下生物量(5.43 g/m~2);而在水分添加条件下,氮添加较对照分别增加58.2 g/m~2和117.64 g/m~2.本研究结果表明,禾类草地上生物量与其氮含量呈正相关关系,杂类草地上生物量与土壤含水量呈正相关关系,这可能是氮素添加提高禾类草地上生物量和水分添加提高杂类草地上生物量的重要机制之一;在内蒙古干旱半干旱地区仅氮素添加(10 g m~(-2) a~(-1))的措施可显著增加禾类草的地上生物量,有利饲草产量的增加,如需增加菊科、豆科等其他杂草的生物量,可考虑水分的补给.
[Abstract]:In order to understand the effect of atmospheric nitrogen deposition and precipitation pattern change on grassland biomass, nitrogen and water addition control experiments were carried out in typical temperate grassland of Inner Mongolia. (CK), nitrogen (10 g m-2) a ~ (-1), (60 mm m-2) a ~ (-1), nitrogen was added in the experiment. Water was treated with (N10g m-2) a-1 water (60 mm m-2 a-1) at the same time. The results showed that: (1) the total biomass (403.03 g/m~2) and aboveground biomass (279.97 g/m~2) of nitrogen addition treatment were higher than those of control treatment. Both underground biomass (123.07 g/m~2) and grass grassland biomass (165.35 g/m~2) increased significantly. However, the biomass of hybrid grassland did not change significantly. (2) the aboveground biomass (200.93 g/m~2) was significantly increased by water addition (200.93 g/m~2), and the biomass on hybrid grassland (177.82 g/m~2). But the below-ground biomass (- 110.39 g/m~2) was significantly decreased, but the total biomass and the biomass on the grasses grassland were not significantly changed. (3) the water addition significantly increased the below-ground biomass and the biomass on the grasses grassland. However, there was no significant effect on total biomass, aboveground biomass and biomass on hybrid grassland. Further analysis showed that nitrogen addition significantly increased biomass (107.15 g/m~2) and underground biomass (5.43 g/m~2) of grass grassland without adding water. Under the condition of water addition, the nitrogen addition increased by 58.2 g/m~2 and 117.64 g / m ~ (2), respectively, compared with the control. The results showed that there was a positive correlation between biomass and nitrogen content in grass grassland, and a positive correlation between biomass and soil water content in hybrid grassland. This may be one of the important mechanisms of nitrogen supplementation to increase biomass on grass grassland and water addition to increase biomass of hybrid grassland. In the arid and semi-arid area of Inner Mongolia, only the addition of nitrogen (10g m-2 a-1) can significantly increase the aboveground biomass of grasses, which is beneficial to the increase of forage yield, such as the biomass of other weeds such as Compositae, Leguminosae and so on. Water supply can be considered.
【作者单位】：四川农业大学动物科技学院;中国科学院地理科学与资源研究所生态系统观测与模拟重点实验室;四川农业大学生态林业研究所;
【基金】：国家自然科学基金项目(31570 437) 中国科学院地理科学与资源研究所青年人才项目(213RC203);中国科学院青年创新促进会项目(2015037)资助~~
【分类号】：S812

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