Dr. Wesley H. Dempsey
824 Karen Dr
Chico, CA 95926
Bidwell Park and Playground Commission
The prescribed grassland burns in the park have been definitely successful, as of this date, in reducing yellow star thistle (YST). Meanwhile, the native bunch grasses, particularly purple needle grass ( Nasella pulchra) and deer grass (Muhlenbergia rigens), have been stimulated by the nutrients in the ashes and the shoots are already 4 to 6 inches tall.
Some specific comments are listed below.
1) Reduction in YST. Counts in 20 small plots on 11/14/00 in the Alligator Hole burn area gave some revealing results. Over about 75% of the burn there are no YST seedlings. In the densest YST sections (as indicated by charred stems) there are 90% fewer seedlings than in unburned plots. A walkthru of the Easter Cross burn indicated similar results. I was frankly surprised at the effectiveness of the burns and felt that the expense and effort on your part were well rewarded.
2) Enhancement of perennial native bunch grasses. Before 1850, these areas were bunch grass prairies with clumps of purple needle grass 2 to 12 inches in diameter and, in moist areas, deer grass hussocks several feet each. On the eastern edge of the Alligator Hole burn there are several acres of such a prairie; between the clumps are some struggling YST plants and other weeds being definitely outcompeted. Within the burn, the charred clumps of purple needle grass are readily distinguished and already sport 4 to 6 inches of new green growth. The same is true for the deer grass. These grasses have a vigorous headstart on the weeds and should do well this year.
3) Enhancement of perennial native “geophytes” (plants with underground bulbs, corms, and rhizomes). Examples of these plants here are mariposa lily, several brodiaea species, odontostomum lily and many others. These haven’t appeared above ground yet; but when they do, they should show vigorous growth from the nutrients released by the fire.
4) Effects on the blue oaks. The trees on the Alligator Hole burn were not protected from fire as those on the Easter Cross burn were and are in bad shape (due in part to the August backfire also). It is obvious that future burns should involve protection of the oaks.
5) Effects on wildlife. The new growth stimulated by the burns is already being enjoyed by browsers for it is succulent and nutritious. I doubt any animals, other than insects, were impacted by the burns. Any ground nesting birds (meadowlarks, horned larks, and sparrows) have fledged by early July.
6) What Next? It would be a shame not to take advantage of the temporary reduction in weeds and increased fertility of the soil. We should make an immediate effort to revegetate these burns before the weeds return with new vigor (one or two years). Volunteers from the Americorps, CNPS, Sierra Club, etc. could easily carry out revegetation for they have been successfully doing it locally for a number of years. I would be glad to help in any way.
My suggestions follow:
a) Take 1-inch plugs from adjacent purple needle grass and deer grass clumps and plant them in the burn. This can be done by unskilled volunteers with trowels and bulb planters. Unless rain is predicted, the plants should receive a quart of water.
b) Obtain bales of purple needle and deer grass (with seeds) from commercial sources and spread the hay out over selected areas. The Nature Conservancy has done this with great success at Dye Creek and elsewhere.
c) Plant seeds, raking them in and tromping them down.
d) Plant blue oak acorns, particularly on the sloping portions of the area (they might not do well on the heavy clay soil of the flat area).
I particularly recommend that you take a look at the existing bunch grass “prairie” just east of the Alligator Hole burn; in fact, I will gladly show it to you (call 342-2293). This is what we should aim to establish after burning.
Wesley H. Dempsey
Emeritus Professor of Biology