Does elevated temperature and doubled CO2 increase growth of three potentially invasive plants?

Sheppard S, Stanley MC. (2014) Does elevated temperature and doubled CO2 increase growth of three potentially invasive plants? Invasive Plant Science and Management 7: 237–246. PDF.

Summary

Increases in CO2 and temperature drive plant growth, development, and function, and may favor invasive plants under climate change. However, we still know very little about how climate change factors interact to affect invasive plant species. Sheppard and Stanley (2014) addressed this knowledge gap using growth chambers to study the effects of elevated temperature and CO2 on seedlings of three non-native tree species in New Zealand (bungalow palm, Archontophoenix cunninghamiana; common guava, Psidium guajava; Queensland umbrella tree, Schefflera actinophylla). These species are potential sleeper species, meaning they are naturalized but predicted to become invasive with climate change, making them ideal for understanding the potential effects of climate change on expanding invasive species. Under experimental growth conditions, only S. actinophylla showed increased growth in response to elevated CO2, and in general no species responded to changes in temperature, or to the combined effects of CO2 and temperature (with the exception of allocating more growth to roots). This study suggests that plant response to climate change is species-specific, and thus not all invasive species will require equal management as the climate changes. Additionally, CO2 may be more important than temperature when predicting climate impacts on woody species. 

Take home points

  • Invasive tree responses to climate change are species-specific

  • For woody invasive plants, increasing temperatures may have little to no effect on their growth in early stages

  • A common response to climate change in trees might be increased allocation to roots rather than shoots

Management implications

  • Not all invasive species will require equal management effort under climate change

  • Species that show a positive response to global change experimentally are a high priority for management

  • Consider prioritizing species at the early stages of invasion before increased CO2 and temperatures may advantage these species. 

Keywords

Shifting Seasons; Impact Study; Experiment; Invasive Plant; Terrestrial Habitat