Tradeoffs between growth rate and water-use efficiency in seedlings of native perennials but not invasive annuals
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Tradeoffs among species’ traits play an important role in shaping communities. These relationships may also mediate community response to environmental change. In plants of water-limited ecosystems, tradeoffs between growth and water use may impose an important physiological constraint within and across species. I investigated how functional traits associated with this tradeoff differ between seedlings of native perennials in California and the invasive annuals displacing them. I created plant community mesocosms of native and invasive species grown under altered N and water availability, measuring multiple plant functional traits. Natives responded positively to N and water when grown separately, but grew best under low resources when in competition with invasives. Invasives grew much larger than natives and exhibited traits associated with rapid growth. Native species also suffered a tradeoff between relative growth rate (RGR) and water-use efficiency (WUE), while nonnatives exhibited both high RGR and high WUE, especially under high resource availability. The ability to grow rapidly and use limiting resources efficiently undoubtedly contributes to the dominance of these invasive species over native seedlings. Such superior trait combinations and differences in physiological tradeoffs could explain reduced native seedling establishment and restoration success in the presence of these invasives.
KeywordsNitrogen deposition Drought Relative growth rate Water-use efficiency Ecological tradeoffs Coastal sage scrub
This work was supported by a NSF Doctoral Dissertation Improvement Grant (DEB-1501110) and the National Park Service Air Resource Division (TASK AGREEMENT J8C07110022). I am grateful to Edith Allen for her advice throughout the experiment.
- Allen EB, Eliason SA, Marquez VJ, Schultz GP, Storms NK, Stylinski CD, Zink TA, Allen MF (2000) What are the limits to restoration of coastal sage scrub in southern California. 2nd Interface Between Ecology and Land Development in California. USGS Report 00–62:253–262Google Scholar
- Funk JL (2013) The physiology of invasive plants in low-resource environments. Conserv Physiol 1Google Scholar
- Kimball S, Gremer JR, Barron-Gafford GA, Angert AL, Huxman TE, and Venable DL (2014b) High water-use efficiency and growth contribute to success of non-native Erodium cicutarium in a Sonoran Desert winter annual community. Conserv Physiol 2Google Scholar
- Kimball S, Funk JL, Spasojevic MJ, Suding KN, ParkerS, Goulden ML (2016) Can functional traits predict plant community response to global change? Ecosphere 7.Google Scholar