Participants at the North American Invasive Plant Ecology and Management (NAIPSD) Short Course came from as far south as Mississippi to the northern reaches of Saskatchewan and Alaska. Landowners, County Extension Educators, Weed management personnel and Natural Resource Conservation Service (NRCS) staff from eight different states attended lectures to learn about the latest research in the control of species that invade and overtake the native flora. This second annual short course was held June 26-28, 2012 at the West Central Research and Extension Center (WCREC) in North Platte, Neb.
An invasive species is typically not native to an area, but its introduction may create a population that dominates. Much of the current research involves plant identification, detecting uncontrolled populations and planning management of that population. Controlling weed populations requires a knowledge of that plant's growth habits and spreading tendencies. Extensive research continues to be done to find effective ways to track populations and devise management plans that are cost and labor effective.
The expanse of participant locations was networked by the realization that some species are a concern in areas all over the continent. A benefit of conferencing with others in the field is the generation of new ideas. As participants shared their approach to weed management plans, discussion and brainstorming were other means of learning about control strategies.
Technology is taking a role in identifying and tracking species populations. Lisa Rew, Montana State University, introduced information about online programs that can be used for input of population data. The program will incorporate information related to the plot's geographic tendencies such as elevation, topography, wind direction, etc., with data collected pinpointing the target species' population. A map can then be created to predict the expected spread of that species dependent on the geographic tendencies, present vegetative cover and invasive species growth habits. That map can be used to devise a management plan for the target species.
Tim Prather, University of Idaho, spoke on the use of sensors to identify populations. Sensors can be located on satellites or on planes that fly over areas of concern. The sensors measure the light reflected off of plant populations. Selection of the sensor type is dependent on the goal in mind and how specific the data must be. Prather advised using sensor detection when the plant population would have a more distinct color presence against the other foliage.
Once sensor readings are taken, a management plan can be made, but many factors need to be considered in working out the plan. Prather advised that those working with weed populations understand the invasive species' growth habits, competitive tendencies, favorable conditions and susceptible habitats. It is also important to study maps showing wind direction as well as expected and historical plant movement.
"If you are going to prioritize, you go to the areas of higher susceptibility," said Prather.
In devising a treatment plan, terrain accessibility will influence the type of application selected whether by plane, sprayer truck, ATV or backpack sprayer. The treatment plan should include suggested herbicides according to target species priorities. Budget allocations should consider plant movement models in order to project the degree of treatment required for future spread.
Afternoon tours featured properties that were involved in research or consultative work to eliminate invasive species and return land to a productive state of use.
At a site along the Platte River, observations are being taken to determine the effectiveness of treatments to eliminate phragmites. Steve Young, WCREC Weed Specialist, is managing the strategies used to control the phragmites and re-establish native grasses.
The area was first sprayed with mesotrione, then all plant debris was burned last fall.
"Burning could put this plant at a competitive disadvantage, so then we might have an edge on control," said Young.
It may require a series or combination of interventions to entirely keep the phragmites suppressed so that the introduced native grasses can become established. Several native grasses were planted in the test plot to determine the most competitive grass species.
The group next traveled to view a revegetation study on rangeland. Work has been done to control the cheat grass and eastern red cedar populations.
Three plots have been designated to compare treatments to eliminate cheat grass. The area was first sprayed with Paraquat to create a flammable debris. After burning the plots off, the area was divided into subplots in which random subplots were treated with glyphosate before the seeding of various warm season grasses. The lack of precipitation has had a negative influence on the success of the research, but the work on the test plots will continue.
The property had dense populations of eastern red cedar at the beginning of the project. The cedar encroachment had reduced the grazing capacity and grass production. During the first year, many of the trees in the canyon bottoms and hillsides were removed mechanically. Preparations were made to carry out a prescribed burn this past spring.
The last observation discussion was led by Jerry Volesky, WCREC Range Forage Specialist. A hillside had been re-excavated by a utility company, so the hillside was bare and very vulnerable to erosion. Due to the removal of the top soil, it was also very low in nutrients and organic matter. The landowner selected a mix of native grasses and forbes to reseed the hillside along with a cover crop of oats. A mulch of prairie hay or partially decomposed wood chips was used. In evaluation of the growth, Volesky said that it might be best to seed the grasses first, then introduce native forbes later.
The tour finished up with practice at completing a plant survey. Various mapping techniques were discussed before teams carried out a plant population detection.
This it the second year that the NAIPSC has been offered. It is made possible by a grant through the Environmental Trust, and sponsorship by the University of Nebraska-Lincoln, the Society for Range Management and the Invasive Plant Control, Inc. Other topics and speakers included: Principals of Invasive Species Management, Randy Westbrooks; Invasive Plant Species Identification, John Kartesz; Invasive Plant Anatomy, Anita Dille; Herbicide Mode of Action, Andrew Kniff; Plant Physiology, Suat Irmak; Water and Invasive Plants, Patrick Starks; Biocontrol in rangeland and Riparian Ecosystems, Andrew Coombs; Managing & Restoring Rangelands, Jane Mangold and Matt Rinella and Integrated Management in Riparian Areas, Bob Wilson.