Trail Reports, Santa Rosa Plateau, 2007-2008

10 January 2008
5 February 2008
9 March 2008
15 March 2008
18 March 2008

10 January 2008: Vernal Pool Trail (see Vernal Pool Trail Plant Guide)

As my car leveled out on the top of the Mesa de Colorado after driving up the steep south face, my heart nearly burst with pure pleasure. It was just like old times again; there was water!!

It had been two years since I saw so much water there, due to the last severe drought year. The creek was flowing, there was water running across the road where the creek crossed the road, water was ponding to the left of the road near Via Volcano Road, and best of all, the two small vernal pools were full. There were ducks aplenty enjoying that water, and the landscape was turning green.

Since I doubt the Emerald Isle ever goes a year without rainfall, surely this exceeds the experience that motivated Browning to pen:

The year's at the spring
And day's at the morn;
Morning's at seven;
The hillside's dew-pearled;
The lark's on the wing;
The snail's on the thorn:
God's in his heaven -
All's right with the world.

I met Kay Madore, Linda St. John, Rob Hicks and some other Santa Rosa Plateau Docents at the Vernal Pool Trailhead, and we journeyed to the Main Pool to check it out. The Pool formed on 5 January 2008, so this was Day 6.

The two small pools at the Vernal Pool Trailhead were full, as was the stream draining them. Looking back at those pools near the Perc pit, one could easily see how perilously close those pools are to the end of their lifetimes. It wouldn't take much erosion to deepen that streambed to the point where those pools would no longer hold water. The Perc Pit itself was inside a still-discernable vernal pool that met that fate in the recent geologic past.

Kay, Linda and I were delighted at the number of annuals we saw. I took lots of baby pictures. But I was shocked to see that the non-native wild oats, Avena fatua, was already in bloom in several places along the trail. Fortunately, the numbers of this species were down significantly after two years of drought.

There were a number of curious holes dug close to the Trail in several places. Some openings were almost badger-sized, but they didn't continue at depth like a badger hole would. Rob's best guess was that these were coyotes trying to dig up gophers, and he even found a coyote print in the diggings.

The Pool was only about half full, 9 inches deep out of a full depth of 16 inches. It was very surprising that the Pool was not full, but the likely answer confirmed my long-ago deduction that the Pool is not sustained by a "clay seal", but instead is made of perched groundwater. The groundwater level was extremely low after two years of drought, and hence a lot of the runoff was first used in raising the groundwater level to the bottom of the pool.

This was the flip side of why a shallow, short-lived Pool formed in 2005-2006 even though there wasn't as much rainfall as is normally needed to form the Pool. The 2005-2006 Pool formed from less rainfall since the groundwater was still high after the 2004-2005 torrential soaking.

The pool still held considerable silvery spider webs along the boardwalk and along vegetation. Kay had seen much more extensive spider webs two days ago, with them appearing as a silvery ribbon festooning the edge of the boardwalk in her photograph.

Kay and I assumed the standard observing position with our stomachs on the boardwalk and our eyes inches from the water to see if we could spot fairy shrimp. The shrimp were expected to be about 0.1 inch long today and very hard to see. Kay quickly spotted a red wriggly worm, the larvae of a midge fly. Not much later I spotted a high density of fairy shrimp, and I could easily see that they were swimming upside down with legs covering only half their body. (This wasn't a record for the earliest sighting; I've spotted fairy shrimp at Day 4 in previous years.)

Even though I had already warned that everyone who had not previously seen fairy shrimp should not expect to see them, to my amazement nearly everyone picked up on them quickly. This was astounding, since both Kay and I have spent five minutes with people trying unsuccessfully to get them to see a high density of ONE INCH long shrimp that were ten times larger! One thing that helped immensely was that the breeze was blowing flotsam et al on the surface of the water north, but the shrimp were swimming mostly south, and the sun was at a good angle to light the shrimp optimally.

Pool fun over, everyone returned to the trailhead except Linda, Kay and myself. We first weeded out ~five curly dock plants growing next to the boardwalk. Linda found a curious dead spider upside down in the water that she will try to identify. I discovered some "toad eggs" near the spider, and took a sample to confirm the determination at home. Much to my astonishment, they turned out to be the spore cases of clover fern, Marsilea vestita, just as suggested to me by Daniel Marion!

We then continued on to the lip of the Mesa in order to check out more baby plants. We met two people coming up who confirmed that the trail was a mudpit below the Mesa, so we didn't go any farther.

We met old friend after old friend, all as babies without flowers. We saw thread-leaved Brodiaea, shooting stars, pygmy weed, owl's clover, caterpillar phacelia, blue dicks, bajada lupine, dwarf lupine, liverworts, and muilla, among others. What a delight it will be to see these bloom again in a few months!

On the way back, we photographed other babies we had skipped past previously in order to get to the Pool more quickly. Western buttercup and angel's gilia were the highlights.

With just an hour left of daylight, Kay and I drove to the Visitor Center and photographed more babies on the Granite Loop Trail. The highlight there was small-headed clover, and dwarf athysanus.

5 February 2008: Vernal Pool Trail (see Vernal Pool Trail Plant Guide)

Kay Madore checked out the pool on 4 February 2008, and told me:

The pool is so full that it is flowing over the boardwalk in several places and even more when you walk on it. So many wind-made waves lap onto the boardwalk, too. Because the water is so close to the edge, you can see all kinds of little critters easily.

So of course I had to check it out.

There was indeed water, water everywhere. There were even springs that had broken through the pavement in several places along Avocado Mesa Road! The Main Pool was overflowing; this was the first time in memory I recall seeing water flowing through the break in the dam.

The water was still above the boardwalk in places. I measured the depth to be three inches above its normal full depth (the height at which no water flows through the break in the dam). This means that as much water continues to flow into the pool, from drainage and groundwater flow, as is flowing out through the break.

It was indeed exceptionally easy to see all the critters. It was a real treat to see the vernal pool fairy shrimp at their full size of 1 inch, and to easily see the stalked red eyes on our half inch long Santa Rosa fairy shrimp, since it had been three years since full grown shrimp were present. All the other critters were around except for the tadpoles. They should have been visible now as 1/10 inch long specks, but despite a hard search for them, we saw none. Their delayed development is undoubtedly caused by the cold weather we have had in the last month.

We found more baby annuals to take pictures of, and best of all, we saw the first two flowers of yellow carpet, Blennosperma nanum. However, none of the other annuals showed any evidence they were even thinking about forming buds, so it will still be a while before there are many blooms.

8 March 2008: Vernal Pool Trail (see Vernal Pool Trail Plant Guide)

This report is from Kay Madore:

Stella Richardson joined me at the SRP yesterday for a hike to check on the current wildflower bloom. I arrived earlier than Stella and since they had told me at the Visitor's Center that fairy shrimp were still in the big pool, I decided to check it out for myself. My last visit to the pool was on February 28. The Press Enterprise had just published an article about the pool that included a color photo. Even though it was reported that the fairy shrimp were all dead (based on information from many years of observation) zillions of visitors showed up to view the pool and the famous "chocolate lilies".

After directing several groups of people to chocolate lily locations, I finally arrived at the big pool at 11:30. Stella joined me at 1 pm.

It was windy and quite chilly at the pool. Most of the surface algae that I had observed on February 28 were gone and the water was amazingly clear. Abundant sunshine made viewing the pool critters quite easy, even while standing.

Many tadpoles were already over an inch long but there were no garter snakes snacking on them. Since the night temps have still been quite cold, I surmise that its been too cold for them to be very active. Although I had seen several garter snakes in the previous weeks but only on the vp trail itself. Several dead western toads were lying at the bottom of the pool, but unlike the previous few weeks, we did not observe any mating pairs.

The red/orange triangular-shaped Copepods (~cyclops) were the most abundant critters in the pool and most of the visitors thought these were the fairy shrimp. I had everyone lie down on their tummy to get a closer look at the water (I love this part) so I could point out the "real" stars of the pool. Our lovely Santa Rosa Fairy Shrimp were easy to see because to my surprise - there were BAZILLIONS of them!!!

Yep - that was BAZILLIONS of fairy shrimp!

Many of the mature Linderiella santarosae had visible egg sacks and were over 1/2" long. But the biggest surprise was seeing ZILLIONS of ~1/4" young fairy shrimp!!! In a 12" sq. water column, I stopped counting at 100+. Once you knew what to look for, you could easily see these "zillions" of fairy shrimp while standing on the boardwalk.

The only reasonable explanation for this is that there must have been a second hatching of the Linderiella. We did not see any of the larger species of fairy shrimp.

As Tom Chester would say -- "Don't that beat all."

In previous years of observation, I believe since 1996, all of the fairy shrimp on the plateau have died within 38-60 days of hatching and we have never seen a second hatching of either species. I personally have been observing the pool critters since I became a docent in 2000. Even in 2005 when we had an early pool that lasted through June, we never saw a second hatching of fairy shrimp.

According to authorities, the 2005 pool should have seen optimum conditions for long-lived shrimp and a second hatching of shrimp. In other areas, shrimp live 70-140 days. I was helping Tom with his plant trails lists in that wonderful year of abundant rainfall, and we were on the reserve at least twice a week for several months. Plus I spent many weekend volunteer hours on my tummy at the vernal pool helping visitors view the critters. Yet our observations in 2005 were consistent with previous years.

So this poses some very interesting questions. Why are the shrimp living longer this year and why a second hatching?

I'm just glad they are here for a longer visit this year so we can continue to admire them.

15 March 2008 from Kay Madore:

When I arrived at the visitors center around 11:30, it was cloudy, quite windy and chilly. It had been sunnier and a lot warmer at home in Brea when I left at 10:15. I had staved off catching my husband's cold for two weeks but now I was definitely feeling the symptoms creeping into my body, wondering if it had been a good idea to come. But I had given my word to help visitors at the vernal pool and really wanted to see the changes at the pool from my last visit on March 15.

First I helped out in the visitors center for 45 minutes, which wasn't nearly as crowded and hectic as on Sunday the 15th, which felt like we were in the middle of a stampede. The Press-Enterprise had featured an article on the vernal pool on Saturday which sent hoards of visitors to the SRP. It was so crazy that I decided to make an impromptu "flower" board displaying pix of the most showy flowers and where to find them. I took some pix out of my SRP book and some from the vc flower book and put them on the A-framed easel. Naming the flowers, I listed where they could be seen, and marked a map with all the chocolate lily locations. Mary Ruth made a much nicer looking display during the week. Ranger Kevin Smith said there had been 1200-1400 visitors last Sunday and had taken in a record amount in day use fees.

As usual, it was even colder and windier at the vernal pool trail head when I arrived at 12:30 so I added my docent vest and jacket to my under sweater and docent shirt. The cloud cover kept many of the flowers from opening so visitors were disappointed.

At the pool it was even colder and I was freezing! You could tell the pool had gone down a bit but I forgot the measuring tape again. There was much more yuckie looking algae next to the boardwalk this week and with the wind rippling the water surface, the center boardwalk area was the best place for critter viewing. Last Sunday I had seen the first garter snakes in the pool so I wasn't surprised to see a large decrease in tadpoles. Only 0-2 tadpoles were up against each board compared to 10-20 last Sunday.

There were far fewer fairy shrimp visible than 6 days before. I had seen many mating pairs the previous week so some had probably died and of course they move around the pool especially when it's windy. I again observed several mating pairs, mature females with egg sacks, all full sized with some nearly 3/4", and lots of young'uns ~3/8' long, although not as many young ones as the week before.

I forgot to mention in a previous report that on 2-18 I saw the largest fairy shrimp ever. A vernal pool fs 1 3/4 -2 inches long!! It had this huge tail. At first I thought it was a mating pair but further observation showed it to be a single shrimp. When he would make a sharp turn he almost ran into his own tail!

It was soooo cold that I left the pool after less than an hour and walked down the vp trail to the bench below the mesa. That trek rewarded me with the first owls clover in bloom. Nancy Backstrand had told me at the trail head that someone had seen a brodiaea in bloom, describing it to her. I looked but didn't see any in bloom and none even with any scapes yet. It was warmer off the mesa so I just rested on the bench awhile and enjoyed the beautiful view. Feeling the cold getting worse, I decided not to do any hiking in the chilly, windy air. A bunch more people had shown up on the boardwalk so I spent some time helping them. But again the cold got the best of me so I headed home. Kevin met me on the trail and we walked out together. There were a lot more people coming now; I was amazed they wanted to be here enough to be out in the cold air.

Another wonderful but chilly day at SRP.

18 March 2008: Vernal Pool Trail, S. Trans Preserve Trail, Hidden Valley Road, S. Los Santos Trail

From 10 a.m. to 1 p.m., Carole Bell and I gave a tour to the Land Steward Group from Orange County. Afterward, a group of ten of us took the Vernal Pool Trail to the Adobes, with three of returning by the S. Los Santos Trail and the rest by the Vernal Pool or S. Trans Preserve Trails.

The SRP is ablaze with color right now nearly everywhere! We are not only getting the expected "double bloom" this year, but the blooms are much more visible because the non-native grasses are not hiding them as much as usual.

The "double bloom" is because every year only some fraction of annual seeds are primed to grow. Our native annuals do not germinate all their seeds every year, similar to the habit of many successful weeds. (Every gardener knows the phrase One year's seeding, seven year's weeding.) This year, not only are we getting the germination of seeds primed to grow this year, we are also getting the germination of seeds scheduled to grow last year but that never got enough rain to germinate then.

The non-native annual grasses also didn't grow last year, so their dead stalks are not present to hide this year's bloom. The current year's growth of non-native annual grasses is lower than normal (italian rye grass is not present at all, since its seeds are an exception to the general rule and only last a single year), and many of them are not very tall so far this year.

As Dave Stith pointed out, the flower of the day was clearly blue dicks. They were everywhere, and in places were producing quite a show. Red maids are a close second, being more abundant this year than in any year in the last decade nearly everywhere in southern California.

Ground pinks and blennosperma are roughly twice as abundant and showy as usual.

The chocolate lilies are having a superb year. Some stalks have seven flowers on them instead of the usual two flowers! They are at peak bloom now on the route we took, and will be declining soon, since there are few buds yet to open. Milkmaids are also having a good year.

We saw warty spruge, Euphorbia spathulata, coming up in numbers not seen since 2003, which again was a year after a severe drought. Perhaps this species is a drought follower!

One species not having a good year is western buttercup. It seems to never like good rainfall years. Instead, it has had its best displays in low-rainfall years. Go figure!

While a number of bush lupines look good, overall their display is decreased this year because a number of big bushes died last year from the drought. It will be at least several years before they produce a great display again like they did in 2005, since we will have to wait for seedlings to become big bushes.

The Main Pool is also having an exceptional year. The pool is absolutely teeming with Santa Rosa Fairy Shrimp and orange-red copepods (Cyclops). The shrimp are all either mating or carrying eggs. It is so cute to see the "double pairs of eyes" on what look like especially long shrimp, with the "extra" pair of eyes in the middle!

Carole Bell had an amazing experience. While standing on the boardwalk, a two-striped garter snake came out of the water, laid at her feet and proceeded to check her out with tongue flicking madly! Neither she nor I had ever seen such behavior before.

The pool is also still full. Groundwater obviously continues to pour into it to keep it full.

The pool has an unusual "mud bank" surrounding the edge of the water where nothing is growing. Normally that area would be filled with vernal pool popcorn flower or annual hairgrass. It looks like tons of algae were deposited there, smothering the area. I've never seen such a mud bank in my 12 years or so of observing the pool.

Go to:

Copyright © 2008 by Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
Comments and feedback: Tom Chester
Updated 18 March 2008.