Precipitation addition during growing and non-growing seasons interactively affects the abundance of soil nematode communities in a semi-arid steppe

Abstract

Changes in precipitation profoundly affect the abundance and structure of soil nematode communities. However, many prior studies have focused mainly on examining how alterations in precipitation during the growing season affect the soil nematode community, and little researches in recent years focus on the impact of non-growing season precipitation (snow cover) on nematodes. We conducted a manipulative experiment in a semi-arid steppe to investigated the effects of precipitation addition during growing season and non-growing season and their interaction on the abundance of total soil nematode community and different trophic groups. The results indicated that (1) growing season precipitation addition significantly increased the total soil nematode community and four diverse nematode trophic groups abundances, because of the function of growing season precipitation addition on soil total nitrogen, soil ammonium nitrogen, and soil water contents; (2) non-growing season precipitation addition reduced bacterivores abundance and elevated fungivores and plant parasites abundance because of the precipitation-induced low temperature and variations of the resource availability; and (3) growing season and non-growing season precipitation addition interactively affected soil nematode community abundance. Effect of growing season precipitation addition on the abundance of nematode community under non-growing season precipitation addition treatment (29.6%) was significantly higher than that of without non-growing season precipitation addition treatment (11.1%). Our study provides insights into the functions of seasonal precipitation changes on nematode community abundance and helps forecast responses to seasonal precipitation changes in the soil micro-food web under global change scenarios.