My research focuses on the ecology of invasive species. Invasive species are organisms that spread extensively after being introduced to a new geographic region. Over the past century, humans have intentionally and unintentionally transported species around the world at an unprecedented rate. Most introduced species never become established, but a few spread successfully and cause major economic and ecological harm. I am interested in factors and processes that influence the success and failure of invasions. Pacific Islands appear to be especially susceptible to invasive species problems, making them an ideal setting for this research.
Curtis C. Daehler
Professor of Botany
Examples of current research
Patterns, prediction, and trends among invasive plants
Island invasibility and effects of propagule pressure
Weed Risk Assessments
Predicting invasive plant ranges
Population ecology and evolution of invaders
New GIS-based technologies, together with improved availability of climatic and other environmental data have allowed the development of complex models for predicting species ranges. Of interest to invasion biology is the possibility of applying these models to predict invasive species ranges, if species were to be introduced to a new region. We are currently testing whether European weed ranges along steep elevation gradients in Hawaii can be predicted from the weeds' native ranges in Europe. This project involves field work on Hawaii Island (Mauna Kea) and Maui (Haleakala).
Some ecologists have long held that it is impossible to predict which species will become invasive in a new region. Yet over the past decade, much progress has been made towards predicting the most serious invasive species in some regions of the world. A first step in developing a predictive theory or model for biological invasions is to quantify and analyze patterns of invasions.
- Verbascum thapsus (mullein) invasion on Hawaii Island
- Relative roles of phenotypic plasticity and genetic differentiation in plants that have invaded across steep environmental gradients on Hawaii's high volcanoes
Hypochaeris radicata
A European invader
G. Carr
Pacific islands - an ideal setting for invasive species research
Ecological control of invasive plants - manipulation of plant resources and fire
Ecological control focuses on understanding interactions between pest plants and their environment, with the goal of identifying simple environmental management regimes that will reduce or eliminate populations of invasive pest plants. Sometimes, only small changes in environmental conditions may slow reproduction by an invasive plant or reduce its vigor and/or competitive ability. The challenge is to identify which environmental parameters most affect the invader. I and my students take an experimental approach, manipulating environmental parameters, both in the field and in the greenhouse, to identify conditions under which native plants or non-pest plants can coexist with or outcompete invasive plants. While ecological control has been long practiced for reducing weeds in agricultural settings, the possibility of using ecological control in natural areas has been much less studied.
Continuing interests
Effects of different species of mycorrhizae on plant community structure and invasion
Hybridization between native and introduced plants and its consequences
Natural area invaders on islands