A Rule of Thumb for Controlling Invasive Weeds: An Application to Hawkweed in Australia
We use a bang-bang optimal control model to derive a rule of thumb for an optimal management of invasive weeds, in terms of the marginal benefits and costs of various control actions. Instead of determining the size of infestation under an optimal surveillance measure, the rule specifies the types of land where an invasive weed should be first prevented from establishment, and under what conditions control should be initiated. The types of land are modeled via the heterogeneous vulnerability of land to the weed and likely infestation. This easy-to-use rule is applied to determine how hawkweed should be controlled in Australia, across three potential control strategies: containment, eradication and no action. We investigate this rule-of-thumb in both deterministic and stochastic settings. With uncertainty, when calculating the threshold of when and how to act, we take into account the fact that delaying a control action will incur not only larger damage and a potentially larger spread but also a higher cost from uncertainty in the spread of the weed itself. The land value threshold is thus given by the unit cost of keeping a weed off a parcel of land times the difference between the interest rate and the current weed spread rate plus the effect of uncertainty. An application to hawkweed in Australia is provided. The rule specifies that hawkweed should be immediately eradicated in all types of agricultural lands they currently occupy where the potential damage is larger than 15AUD/ha/year. This generates a full eradication strategy under broad parameter values. Though the cost of removing hawkweeds is significant, it is overwhelmed by the damage if Hawkweeds spread to higher value agricultural land.
|Date of creation:||Sep 2010|
|Contact details of provider:|| Postal: Crawford Building, Lennox Crossing, Building #132, Canberra ACT 2601|
Phone: +61 2 6125 4705
Fax: +61 2 6125 5448
Web page: http://www.crawford.anu.edu.au/research_units/eerh/
More information through EDIRC
When requesting a correction, please mention this item's handle: RePEc:ags:eerhrr:95046. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (AgEcon Search)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.