Soil phoD-harboring bacteria mediate the responses of phosphorus availability to N addition and mowing among soil aggregates
Haiying Cui,
Shanling Wang,
Tianyan Wei,
Xuechen Yang,
Xiuping Li,
Mingcai Fan,
Xiaochong Zhang,
Wenzheng Song,
Jian-Ying Ma,
Wei Sun
Affiliations
Haiying Cui
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Shanling Wang
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Tianyan Wei
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Xuechen Yang
State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 830011 Urumqi, Xinjiang, China
Xiuping Li
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Mingcai Fan
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Xiaochong Zhang
Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China
Wenzheng Song
College of Tourism, Resources and Environment, Zaozhuang University, Zaozhuang 277160, China; Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China
Jian-Ying Ma
Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China
Wei Sun
Institute of Grassland Science, School of Life Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Changchun 130024, China; Corresponding author.
Phosphorus (P), like nitrogen (N), is a major limiting nutrient for ecosystem structures and functions. Soils in grasslands commonly have limited P availability for organisms, especially under global change (i.e., N deposition) and land-use intensification (i.e., mowing or hay harvest). Soil phoD-harboring bacteria regulate P cycling and maintain P supply in soils. However, it remains unclear how P availability responds to N addition and mowing. The potential microbial mechanisms also require clarification among soil aggregates. We conducted a seven-year field experiment to investigate how N addition at different levels (0, 5, 10, and 20 g N/m−2 y−1) and mowing (unmown and mown) affects soil available P in macro- and micro- aggregates in a temperate grassland in Northeast China. We found that N addition markedly decreased available P in macroaggregates, regardless of mowing. In contrast, available P in microaggregates decreased following N addition under mown but increased at addition levels of 10 and 20 g N/m−2 yr−1 under unmown. Our results also showed that soil available P was positively related to the diversity of phoD-harboring bacteria and phoD gene abundance in macroaggregates, and to alkaline phosphatase activity and phoD gene abundance in microaggregates. These findings suggests that microbial characteristics mediating the response of available P to N addition and mowing vary with soil aggregates. Our study highlights that soil aggregates should be carefully protected if we wish to promote the sustainable development of grassland ecosystems and P supply under a scenario of future global change and land-use intensification.
