Eco‐evolutionary responses of Bromus tectorum to climate change: implications for biological invasions. Issue 5 (12th April 2013)

• Record Type: Journal Article
• Authors: Zelikova, Tamara J.; Hufbauer, Ruth A.; Reed, Sasha C.; Wertin, Timothy; Fettig, Christa; Belnap, Jayne
• Is Part Of: Ecology and evolution. Volume 3:Issue 5(2013:May)
• Page Start: 1374
• Page End: 1387
• Publication Date: 2013-04-12
• Subjects: Bromus tectorum -- cheatgrass -- climate change -- Colorado Plateau -- phenology; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.542
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract : How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming experiment at two sites in southeastern Utah, we tested this prediction over 4 years, measuring B. tectorum phenology, biomass, and reproduction. In a complimentary greenhouse study, we assessed whether changes in field B. tectorum biomass and reproductive output influence offspring performance. We found that following a wet winter and early spring, the timing of spring growth initiation, flowering, and summer senescence all advanced in warmed plots at both field sites and the shift in phenology was progressively larger with greater warming. Earlier green‐up and development was associated with increases in B. tectorum biomass and reproductive output, likely due early spring growth, when soil moisture was not limiting, and a lengthened growing season. Seeds collected from plants grown in warmed plots had higher biomass and germination rates and lower mortality than seeds from ambient plots. However, in the following two dry years, we observed no differences in phenology between warmed and ambient plots. In addition, warming had a generally negative effect on B. tectorum biomass and reproduction in dry years and this negative effect was significant in the plots that received the highest warming treatment. In contrast to models that predict negative responses of B. tectorum to warmer climate on the Colorado Plateau, the effects of warming were more nuanced, relied on background climate, and differed between the two field sites. Our results highlight the importance of considering the interacting effects of temperature, precipitation, and site‐specific characteristics such as soil texture, on plant demography and have direct implications for B. tectorum invasion dynamics on the Colorado Plateau. Abstract : Climate change is one of the most critical environmental challenges of the 21st century and several lines of evidence suggest that climate change may benefit nonnative plants more than native plants. With a field warming experiment at two sites in southeastern Utah, we assessed how phenology, biomass, and reproduction of an invasive grass Bromus tectorum responded to 4 years of warming and with a follow‐up greenhouse experiment, tested whether changes we saw under field experimental conditions influenced offspring performance.