求助以下3篇文章：
1.
Soil-atmosphere exchange of nitrous oxide,nitric oxide and methane under secondary of pasture to forest in the atlantic lowlands of costa rice.
Michael Keller
Global biogechemical cyeles vol.8 no.4 page:399-409 1994
2.
Annual nitrous oxide flux and soil characteritics in sagebruch steppe ecosystems
Pamela A Matson. Carol Volkman.ect
Biogeochemistry vol.14 no.1 1994 pp:1-12
3.
Transport and loss of nitrous oxide in soil water after forest clear-cutting.
William B Bowdena and F H Bormann
Science 22 august 1986 233:867-869
谢谢各位高手的帮助！！