Factors affecting the current range limits of the invasive species Linaria dalmatica along an elevation gradient in the Northern Range of Yellowstone National Park. 

Recently, there has been increased interest in the demographics of non-native plant species in mountain systems.  It has become apparent that these areas are not resistant to invasion by non-native plants.  Many studies have documented the presence of non-native plants in mountain systems and noted reduced abundance of non-native plant species as elevation increases.  Some studies have suggested that dispersal limitations, decreased land area, or decreased disturbance could lead to the observed decreases in abundance.  However, there is a growing body of literature that suggests that environmental limitations may be responsible for this trend.  If the goal is to prevent non-native plant species invasions in mountain systems, we need to understand what is controlling their current range limits within these areas.  Such information will also prove useful in anticipating what may happen within these systems under a climate change scenario that results in increased temperatures at high elevations. 

The goal of this research is to determine if environmental factors are responsible for limiting the current ranges of a non-native (Linaria dalmatica) and a native plant species from the same family (Castilleja miniata) along elevation gradients within the Northern Range of Yellowstone National Park (YNP).  Information about the fitness and demographics of L. dalmatica and C. miniata gathered from monitoring plots will be coupled with environmental data in an effort to determine the effects of changing environmental conditions along an elevation gradient on the species’ ability to grow and reproduce.  We will also try to determine how the presence of roads may affect the dispersal ability ofLinaria dalmatica.  Although this research project focuses on one non-native species, combining the results with other similar studies from mountain systems around the world should allow us to see if there are any general processes present within this phenomenon which could be used to guide management and policy making at larger scales.

Selected Publications:

Fredric Pollnac, Tim Seipel, Charles Repath, Lisa J. Rew (on-line) Plant invasion at landscape and local scales along roadways in the mountainous region of the Greater Yellowstone Ecosystem. Biol Invasions

Rew, L.J., and Pollnac, F.P.  2010. Seed Dispersal by Vehicles.  News from the Center for Invasive Plant Management, April 2010.

Harbuck, K.S.B., F.D. Menalled, and F.W. Pollnac. 2009. Impact of cropping systems on the weed seed banks in the northern Great Plains, USA. Weed Biology and Management 9:160-168.

Pollnac, F.W., B.D. Maxwell, and F.D. Menalled. 2009a. Using Species-Area Curves to Examine Weed Communities in Organic and Conventional Spring Wheat Systems. Weed Science 57:241-247.

Pollnac, F.W., B.D. Maxwell, and F.D. Menalled. 2009b. Weed community characteristics and crop performance: a neighbourhood approach. Weed Research 49:242-250.

Pollnac, F.W., L.J. Rew, B.D. Maxwell, and F.D. Menalled. 2008. Spatial patterns, species richness and cover in weed communities of organic and conventional no-tillage spring wheat systems. Weed Research 48:398-407.

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