Reclamation success depends on careful thought prior to disturbing landscapesWritten by Natasha Wheeler
Douglas – University of Wyoming PhD student Beth Fowler works with weeds and vegetative reclamation on disturbed worksites.
“We typically work with very young species that we have seeded and we want to get established,” she notes.
Some of the issues Fowler faces in her work include harsh Wyoming wind conditions, limited precipitation and competition from weeds.
“Prevention is crucial when we talk about weeds,” she states.
Fowler continues, “We also need to think about what decisions we make to help the shift between undesirable species and desirable species.”
Just because weeds can’t be seen doesn’t mean they have been eradicated. Hidden seed banks can stockpile many weed species. Halogeton seeds, for example, can survive in the soil for up to 10 years.
“When we respread soils over an area, we don’t have a blank slate,” she explains.
Many weed species are prolific seed producers, with seeds that can remain viable for long periods of time.
“Many weedy plants can rapidly reestablish in newly disturbed areas,” Fowler adds.
Undesirable species can reduce forage, affect availability and quality of desired species and change ecosystem functionality and hydrology.
“Sometimes, we can get livestock poisoning or soils can be changed, and there can be an increase in fire propensity, for example when we talk about cheatgrass,” she mentions.
When working with reclamation sites, managing weed species in the early stages of infestation can increase the chances of success.
“The larger the infestation, the lower the success and the higher the effort, money and time for managing and controlling the population. Once we get large areas of infestation, the less likely we are to be able to completely eliminate the weed from the system,” Fowler explains.
Many different tools and techniques can be used to manage weeds, depending on the area and the species.
“We need to make sure our management practices work together,” Fowler comments.
Applying herbicide after the introduction of an insect biocontrol agent, for example, may be hazardous to the beneficial insects.
“Another example is the replant interval for specific herbicides. If we apply herbicides in the fall, as soon as the soil freezes, the replant interval stops. We may apply an herbicide in November but not be able to plant until March or April,” she says.
Newly emerging plants may also suffer more impacts from herbicide application.
“We have to ask how our desirable forbs and shrubs interact with our desirable grasses, as well,” she continues.
Considering the whole landscape is also important in site reclamation.
“Before we do anything, we need to make sure we are looking at the site and what’s out there before we start,” she remarks.
Weeds that are present before disturbance begins are likely to be a problem when reclamation takes place.
“We need to understand what is probable and possible at a given site. We are not going to expect that all of an area with six inches of annual rainfall is going to get the optimum 15 inches of rain for a specific species,” Fowler notes.
A management strategy should be developed with realistic goals and steps to move toward those goals. Infestations should be managed early before they spread, and it is important to get an accurate survey of the whole ecosystem when working to control species.
“As always, we need to monitor and follow up on treatments. We need to be flexible in what we are doing to manage systems to end up where we want to be,” Fowler concludes.
Fowler shared her insights during a July 2015 reclamation workshop held outside of Douglas.