RS 478 Lecture 16: Weed Control and Restoration Regulation

4 Pages
Unlock Document

Rangeland Ecosystem Science
RS 478
Mark Paschke

RS 478: Lecture 16 Weed Control and Regulations in Restoration Outline 1. Introduction 2. Approaches 3. Considerations 4. Restoration Regulations 5. Industry Regulations 1. Introduction • What is a weed? o Typical characteristics of weeds: Annuals or short-lived perennials, Adapted to high nutrient soils, Fast growth and high seed production • When is weed control needed? o Presence of weeds at the site is a reason for restoration; Disturbance/restoration creates opportunity for weed establishment Review Question: What is a weed? ü Any plant growing where it is not desired 2. Approaches • Avoidance: • Don’t introduce weeds to your site via: Mulch, Topsoil, Restoration seed mix, Containerized stock, Livestock • Survey your site and surrounding areas for weeds • Check the soil seedbank at the restoration site • Chemical: Application of chemicals that are toxic to undesirable species. o Chemical selectivity, Broadleaf herbicides, Others (grass specific, cool- season specific, etc.), o Application timing: When weeds are vulnerable but desired species are not or immediately after seeding desirable species o Application placement: Depth in soil, Spot spraying, Cut stump spraying o Special consideration for chemical control in restoration: Non-target effects/drift Other plants, Native genotypes (good competitors with weeds,) Other trophic groups, Regulations, Public perceptions, What replaces the weeds • Physical: Hand pulling or hoeing, Fire, Grazing, Mowing, Chaining or masticating, Flooding, Mulch, Solarization • Cultural: Competition Cover crops, Successional management o Native weeds can be important in plant community development after disturbance • Biological Control: o Enemy Release Hypothesis of Darwin (1859) & Elton (1958): Invaders are successful because they have left their natural enemies behind o Introduction of natural enemies from the weed’s native range. o Once released, biocontrols are inexpensive Can be effective at reducing weed abundance Review Question: What is biological control of weeds? ü A form of control which introduces natural enemies/predators from the weeds native range to reduce/suppress the population Review Question: What is meant by using avoidance as a technique for weed control? ü Avoiding introducing weeds to a site through contaminated seed mixes, mulches, topsoil, etc. 3. Considerations • Any approaches unacceptable for a particular site? Social, economic, cultural considerations? • Were weeds present prior to disturbance/restoration? Are they likely to have large seed bank? viable rhizomes? • What is the spatial extent of weeds at the site? • What is the biology of the weeds? Life cycle? • Have they changed the soil/site? • Budget considerations? Tradeoffs between upfront costs vs long-term control? • Combination of approaches and/or repeated treatment may be needed (Example: cheatgrass) 4. Regulations • Prescriptive vs. outcome based: o Prescriptive – these are the methods you must use. o Outcome based – these are the conditions you must achieve. Review Question: Describe the difference between prescriptive and outcome-based regulations? ü Prescriptive regulations are methods you must use to get to a desired outcome. Outcome based are conditions are must achieve. These lead to defined results without specific direction regarding how those results are to be obtained. Fo
More Less

Related notes for RS 478

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.