Abstract Detail

Ecology

Rodgers, Vikki L [1], Griffith, Alden B [2], Dukes, Jeffrey S [3].

Experimental test of the theory of fluctuating resource availability as a driver for invasion establishment.

Understanding the mechanisms that drive the success or failure of novel plant populations is central to invasion biology. In this study we experimentally tested the theory of fluctuating resource availability with an approach that quantitatively integrates environmental, physiological, and demographic datasets using integral projection models (IPMs). The supply of soil moisture in an old-field community was experimentally manipulated in situ at the Boston Area Climate Experiment (BACE; Waltham, MA, USA) with treatments consisting of 50%, 100%, and 150% of ambient precipitation. Within each precipitation treatment we manipulated the rate at which the resident community could deplete soil moisture by manually clipping background vegetation or leaving it intact. We invaded experimental plots in the autumn of both 2012 and 2013 with seeds of Persicaria lapathifolia, an annual herb that is common to the area, but largely absent from the plant communities at BACE. We recorded complete life-cycle demography for nearly 2,000 P. lapathifolia individuals, environmental variables such as soil moisture and soil inorganic nitrogen, and physiological variables such as leaf chlorophyll and tissue C:N. Overall, increases in soil resource supply and/or decreases in uptake promoted invasion by P. lapathifolia. Furthermore, plots that did not receive manipulations hypothesized to be favorable to invasion were entirely resistant to invasion in 2013 (i.e. total seed production near zero). This is broadly consistent with the theory of fluctuating resource availability, but amid substantial variability across microsites. Although P. lapathifolia in the drought treatment exhibited higher growth early in the growing season, low soil moisture in the summer was linked to reduced growth and survival that alone reduced annual population growth by roughly 40% compared to the high soil moisture treatment. This shift in demographic rates throughout the growing season suggests that antecedent drought may promote invasion in the spring (through a hypothesized negative legacy on background community resistance), but is later countered by the effects of concurrent drought.

Related Links:
BACE site

1 - Babson College, Math And Science Division, 231 Forest Steet, Kriebel Hall, Wellesley Hills, MA, 02481, USA
2 - Wellesley College, Wellesley College Botanic Gardens, Science Center, 106 Central Street, Wellesley, MA, 02481, USA
3 - Purdue University, Department of Biological Sciences, 915 W. State Street, West Lafayette, IN, 47907, USA

Keywords:
invasion biology
demography
soil resources
Persicaria lapathifolia
moisture.

Presentation Type: Poster
Session: P, Ecology Section Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC001
Abstract ID:44
Candidate for Awards:None