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Rainfall variability counteracts N addition by promoting invasive Lonicera maackii and extending phenology in prairie
Author(s) -
Schuster Michael J.,
Dukes Jeffrey S.
Publication year - 2017
Publication title -
ecological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.864
H-Index - 213
eISSN - 1939-5582
pISSN - 1051-0761
DOI - 10.1002/eap.1547
Subject(s) - phenology , deciduous , woody plant , herbaceous plant , growing season , agronomy , biology , environmental science , ecology
Although encroaching woody plants have reduced the global extent of grasslands, continuing increases in soil nitrogen availability could slow this trend by favoring resident herbaceous species. At the same time, projected increases in rainfall variability could promote woody encroachment by aligning spatiotemporal patterns of soil moisture availability with the needs of woody species. We evaluated the responses of two deciduous woody species to these simulated environmental changes by planting seedlings of Quercus palustris and Lonicera maackii into tallgrass prairie communities grown under a factorial combination of increased rainfall variability and nitrogen addition. Lonicera maackii growth was reduced 20% by nitrogen addition, and increased rainfall variability led to 33% larger seedlings, despite greater competition for light and soil resources. In contrast, Q. palustris growth showed little response to either treatment. Increased rainfall variability allowed both species to retain their leaves for an additional 6.5 d in autumn, potentially in response to wetter end‐of‐season shallow soils. Our findings suggest increases in rainfall variability will counteract the inhibitory effect of nitrogen deposition on growth of L. maackii , extend autumn phenology, and promote the encroachment of some woody species into grasslands.