EVENTS

Webinar Details:

Title:

Modeling invasive grass responses to a changing climate in Hawaiʻi: Photosynthesis variation and species saturation

Webinar Description:

Understanding invasive plant responses to climate change is important for developing proactive invasion prevention, management and control plans. Here, we focus on a case study involving introduced and invasive grasses in the Hawaiian Islands. Invasive grasses are of particular concern because many of them pose wildfire risks; furthermore, the grass family includes many thousands of potential species introductions, most of which have not yet spread widely. We used species distribution modeling (SDM) as a tool to explore potential introduced grass distributions and range shifts in response to a moderate climate change scenario. Grasses consist of at least three major photosynthetic types, and our models indicate that response to climate change will likely depend on grass photosynthetic type. Therefore, photosynthetic type may be a useful component of risk assessment for introduced grasses. We also considered likely current and future distributions of invasive grasses that pose the highest wildfire risk, comparing well-established grasses to grasses that are currently limited in distribution and could be feasible targets for eradication. Considering modeled future distributions of these fire-promoting grasses to identify total land area at risk from future grass wildfire, we found that future spread by incipient grasses had only small impacts on the total land area at risk from future wildfires. This is because existing wide-spread fire-promoting grasses can already occupy most of the areas that would be invaded by the incipients. This finding leads us to wonder whether invader impacts may become saturated in some situations, and whether the optimal resource allocation towards control versus prevention of new introductions may favor more substantial resource allocation to control in some situations.

Speaker details:

Dr. Curtis C. Daehler is a Professor and the Associate Director of Instruction of the Botany Department at the University of Hawaiʻi at Mānoa. His research focuses on the ecology of invasive species, population ecology, and plant-animal interactions. Pacific Islands appear to be especially susceptible to invasive species problems, making them idea for research, and he is interested in the factors and processes that influence the success and failure of invasions. Professor Daehler was also formerly the Editor-in-Chief of the journal Pacific Science.

Dr. Kelsey Brock is an Assistant Professor and Extension Weed Specialist in the Department of Plant Sciences at the University of Wyoming. Her extension, research, and teaching program focuses on addressing the challenges posed by invasive plant species, particularly in rangelands and natural areas across Wyoming. Dr. Brock’s work integrates data science, geography, taxonomy, and weed science to develop an “invasion informatics” toolkit that helps detect new invasions, analyze trends, and guide management decisions. She uses both empirical and predictive approaches to study multi-species invasions within the broader context of global change, including biodiversity loss, climate change, and expanding economic activity. Dr. Brock earned her Ph.D. in Botany from the University of Hawaiʻi at Mānoa, and M.S. and B.S. degrees in Plant Biology and Environmental & Conservation Science from the University of Alberta.

Relevant Links:

Brock, K.C., & Daehler, C.C., 2021, Plant naturalization trends reflect socioeconomic history and show a high likelihood of inter-island spread in Hawai‘i, Invasive Plant Science and Management , Volume 14 , Issue 3 , September 2021 , pp. 135 – 146, DOI: https://doi.org/10.1017/inp.2021.18

https://kcbrockresearch.com/

https://www2.hawaii.edu/~daehler/index.html