Information Forestry, December 2007 — Canada’s climate is changing, and forest pests are on the move.

In order to track and predict long-term effects of a warming climate on pests, Natural Resources Canada scientists use a software tool originally developed to help forest managers plan short-term pest control or sampling activities.

Distribution of gypsy moth in Canada from 1964 to 1970. Image © Natural Resources Canada


Distribution of gypsy moth in Canada from 2001 to 2006. Image © Natural Resources Canada

This tool, called BioSIM, links insect life-cycle models to weather data and manages their output to determine the timing of specific stages in an insect’s life cycle—for instance, when an insect reaches the stage most vulnerable to pesticide applications. BioSIM has recently been extended to help in forecasting where current or future climates might favour invasion by an alien species because the weather is, or will be, more suitable for its survival.

“The success of forest pest control programs hinges on the vulnerability of pest populations at the moment of intervention,” says Canadian Forest Service scientist Jacques Régnière, who studies insect population dynamics and developed BioSIM. “With insects, weather conditions are a controlling factor.”

In order to predict long-term climate effects on insect populations, the researchers use data from climate scenarios generated by the Canadian Global Circulation Model that extend many decades into the future.

“Taking BioSIM from immediate applications to seasonality modeling and establishing probability over long time periods was a bit of a leap in complexity, but not much of a change in paradigm,” says Régnière. “Whether you’re looking for short-term or long-term views, it uses the same technology: weather-data management and model-output synthesis.”

Régnière teamed up with fellow-Canadian Forest Service researchers Vince Nealis and Kevin Porter to determine probable range expansion of gypsy moth in Canada. At the Canadian Food Inspection Agency (CFIA)’s request, they analyzed historical records from Natural Resources Canada’s Forest Invasive Alien Species Database, and current and likely future range of gypsy moth in Canada, based on the Gypsy Moth Life Stage model, climate suitability and host distribution. Using the results, the researchers devised recommendations for gypsy moth management strategies, which they then submitted to the CFIA.

Potential distribution of gypsy moth in Canada, #1. Image © Natural Resources Canada


Potential distribution of gypsy moth in Canada, #2. Image © Natural Resources Canada

“The real benefits of models like BioSIM from a quarantine management point of view,” says CFIA Forestry Specialist Shane Sela, “are that they allow us to better assess risks, and more effectively allocate resources to critical areas where potential risk is highest.”

Régnière also worked with Insect Ecologist Allan Carroll to predict range expansion of mountain pine beetle in western Canada. According to their results, eastward invasion by the beetle will continue if current climate trends persist.

BioSIM is capable of determining probability of future range for any species—insect, pathogen or plant—because it is designed to work with any model that encompasses an organism’s life history and response to climate. This emphasizes the need to quickly acquire such information for any species that represents a significant risk to Canada’s forests.

© Natural Resources Canada 2007