Plant Regeneration Study
Henry W. Coe State Park
November, 2007 — August 2008 Progress Report
Dr. Winslow R. Briggs

The original proposal to the State Department of Parks and Recreation was to set up and monitor vegetation changes in a range of different environments both through the season and from year to year in a variety of sites impacted by the fire. These were to be monitored by volunteers given appropriate training and instructions on how to set up unbiased sample plots. Two training session were held and a grant of $22,000 (donor anonymous) to the Pine Ridge Association allowed purchase of cameras and GPS instruments so that volunteers could maintain precise photographic records along with precise date and lat/long coordinates for every image. A large group of volunteers expressed interest in participating in the study. All of the volunteers passed a driving test administered by ranger John Verhoeven before participating, all had radio training, and all had access to 4WD vehicles. We have an FTP site where the data—both images and text—are submitted and it is backed up weekly.

Site selection:
Most of the sites were selected in November and December but a few were identified for study in January or later. We currently are observing 36 sites in the following different categories:

Category Number Of Sites
Meadows 5
Blue Oak Woodland 8
Gray Pine 3
Ponderosa Pine 4
Chamise and Mixed Chaparral 6
Manzanita and Mixed Chaparral 3
Riparian 1
Chaparral Moonscapes (probably chamise) 2
Chaparral Skeletons 4

Among these we have meadow, blue oak, ponderosa pine, manzanita control sites. We are weak on riparian sites as they were hard to maintain during the rainy season.

Site design:

Almost all sites consist of 5 50 x 50 cm quadrats set 10 m apart along a straight line. We established the starting point and the compass direction for the line in all cases. For certain sites it was necessary to set up two parallel lines 10 m apart, with 2 and 3 quadrats, respectively, in order to keep the sampling within a given vegetation type.

Data collection:

Volunteers have photographed the quadrats from the same position on each visit, took closeup images of plants as they were emerging, did preliminary identification when they had the skills, and made detailed notes of what they saw. They have also monitored and photographed trees and shrubs in the immediate neighborhood of their sites to follow their development as a function of the extent of external damage (largely for the oak species, ponderosa pine, and the California bay). As appropriate to their site, volunteers are monitoring the extent of stump sprouting versus seed germination for many chaparral species. Finally they are equipped with a list of species that are sometimes called "fire-followers" for their profusion after a fire and some volunteers are recording the appearance of these species. We expect the monitoring process to continue for several years as the various areas recover. Recovery will clearly be at different rates in the different vegetation types and for some areas such as the moonscapes this process may actually take decades.

Frequency of visits:

Ideally we wanted the volunteers to visit their sites at least once a month. Probably two-thirds of them have come close to meeting this schedule. We estimate that nearly 100 visits were made into the burn area to obtain data.

Quality of data:

As we might expect, there is some variation in the quality of the data. However, a number of sets are really outstanding and there is enough of interest in most others for them to be useful. The site redundancy also mitigates this potential problem. Finally there has been some attrition, not unexpected (along with a couple of additions) to give us 32 present volunteers, some more active than others.

Landsat Images:

We have obtained Landsat images at intervals both before and after the fire. These are in false color that gives us an indication of photosynthetic productivity in various areas. We have funds to continue obtaining them for several years and they will be useful in following major vegetation recovery over time.

Panoramic images:

The very precise panoramic images that are being taken at intervals by Ron Fischler and Bob Patrie allow us to follow the time course of recovery on a scale ranging from landscape down to a few square meters. These will provide a valuable adjunct to the study.


It is well known that certain perennial species that grow from bulbs (geophytes) can flower profusely the first year after a fire. Most of these species found in Coe Park are in the chaparral. During the past spring at a number of different species showed this behavior. Although all of them bloom occasionally throughout the park every year, the numbers flowering this past spring increased enormously over what with casual observation we had ever seen in the past. We have located areas where the bloom was profuse and laid out 1.5 x 1.5 m quadrats within which we have recorded the number of flowering versus non-flowering individuals. We will follow these quadrats over the next few years to follow changes in the ratio of flowering to vegetative plants. A possible exception is Calochortus luteus (yellow mariposa lily) that is often found in great profusion in the absence of fire. We have quadrats from both burned and unburned areas to test this hypothesis.

We have quadrats and the initial year's data for the following species:

Geophyte Species Number Of Quadrats
Brodiaea elegans (harvest brodiaea) 2 quadrats
Calochortus albus (globe lily) 2 quadrats
Calochortus venustus (white mariposa lily) 2 quadrats
Calochortus luteus (yellow mariposa lily) 2 quadrats
Chlorogalum pomeridianum (soap root) 5 quadrats
Triteleia laxa (Ithuriel's spear) 3 quadrats
Zigadenus fremontii (star lily) 2 quadrats
Bloomeria crocea (common golden stars) 2 quadrats

The reason fire stimulates flowering in these species is not currently known. There are four hypotheses:
1. Stimulation by heat shock
2. Stimulation by some compound in smoke or extracted from charred wood
3. Stimulation by the sudden influx of mineral fertilizer from ash
4. Removal of shading with concomitant increase in photosynthesis

Current evidence based just on observation (massive flowering in areas where there was no shade before the fire; massive flowering in areas where the only ash came from a scant grass cover) somewhat favors the first or second hypothesis but some rigorous testing is still required.
We hope to be able to resolve this issue.
Two additional quadrats contain plants of Emmenanthe penduliflora. The seeds of this plant germinate only after a fire, responding to something in smoke, and it is of interest to see whether the stimulus holds over for another year or two.


Eastwood's manzanita is showing vigorous stump sprouting in many areas, especially on Blue Ridge. Big berry manzanita , by contrast is a species that never sprout from the stump. There are areas on Blue Ridge dominated by one or the other species. Manzanita seedlings are also beginning to appear. It is easy to distinguish between the two species as the stems of Eastwood's manzanita is hairy and that of big berry manzanita smooth.
As seedlings of both species are just now emerging, we plan to establish 1.5 x 1.5 m quadrats for both in areas where germination is prevalent in an attempt to measure the relative reproduction rates and seedling survival of these two species.