Outline of Quino Recovery Plan - The Xerces Society

Costs associated with removing thatch and spraying nonnative plants with a
selective herbicide vary among restoration sites, but depend primarily on the
degree to which the natural habitat has been degraded, including the extent of
nonnative plant invasion. The cost of removing nonnatives is generally lowest
for areas that require only spot spraying of individual plants. Removing plants
by hand is costly, especially for large areas. However, hand "weeding" may be
necessary for sites occupied by Quino checkerspot. The de-thatching technique
can be used in conjunction with return visits to spray individual nonnative plants;
and in some instances a “weed eater” can be used instead of spraying.
The de-thatching technique is typically used only during the first year as part of
the site preparation. A crew of approximately ten workers has been used to dethatch
nonnative plants, accomplishing several tasks simultaneously. Activities
include weed-whipping the site (4-5 weed-whips can work at one time), raking
thatch into piles, collecting thatch and placing it into burlap bundles, and taking
the bundles to trucks for removal from the site. Estimated costs per unit area are
given below for using the de-thatch and repeat spraying method for sites
dominated by nonnative plants, but which still have native plants present.
Using this method, 10 workers can de-thatch approximately 0.4 hectare (1 acre)
per day. Costs for the de-thatching range from $4,000 to $5,000 per hectare
($1,600 to $2,000 per acre) (based on a average $20 per hour billing rate for the
laborers and supervision time). The work can be physically demanding,
especially if the thatch material has to be hauled out of steep canyons. If
removing the material is not possible, it can be placed into piles and composted
on the site. The nonnative plants that germinate later from the piles will need to
be controlled because some nonnative plant seeds will remain. After sufficient
rains have fallen in winter, nonnative plant seedlings will require control by
return visits to spray Roundup© or other, more selective, herbicides to prevent
the plants from maturing and producing seeds. Care must be taken to minimize
over-spray onto native species. It is imperative that workers are able to
recognize nonnative plants and distinguish them from native plants.
For the first 2 seasons after de-thatching, repeat spraying with an appropriate
herbicide up to five times in a season costs approximately $8,400 per hectare
($3,400 per acre)in labor (four workers making five spraying visits) and an
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