Friday, June 6, 2014

Wildflowers, Drought, and Other Important Matters



Striped adobe lily in March 2013
              When I think of the term “extreme drought year,” my mind’s eye tends to conjure an image of scorched landscapes, bare ground, and brown as far as you can see. So, when I look at the data from the US Drought Monitor and confirm the depth of this year’s drought, there’s a little bit of cognitive dissonance. You see, of the three springs I have spent on Tejon Ranch, this year’s crop of Antelope Valley wildflowers was by far the nicest I’ve seen. Admittedly, these have not been the greatest three springs for flowers, but it superficially stands to reason that the year with the poorest rain should have the poorest wildflowers.

Striped adobe lily in 2014
                Last year, despite mediocre rainfall, we wound up having a pretty nice spring in the San Joaquin Valley. We were the beneficiaries of several December storms on the San Joaquin side of the ranch. Throughout the San Joaquin fringe, Tejon Hills, and Old Headquarters we were pleased to see extensive color and blooms of some of our rare taxa, such as striped adobe lily (Fritillaria striata), Comanche Point layia (Layia leucopappa), and Tejon poppy (Escholzia lemmonnii ssp. Kernensis). 2014 in contrast has only yielded  brown fields with green highlights.


The "Tejon Milky Way" on April 1st, 2013

The "Milky Way" on April 9th, 2014
                So, what does the state of drought in California tell us about the extent of wildflower blooms in the region? The answer as far as I can tell, is nothing, which complicates my heretofore simplistic understanding of precipitation dynamics. Until now, my assumption had always been that if we receive a lot of rain in winter, there will be a lot of flowers in spring. If there is little rain in the wintertime, no flowers should germinate in the springtime.

Looking south towards Cordon Ridge on April 1st, 2013


Same view as above, but on April 9th, 2014


                BUT many of the plants we count on to produce spring wildflowers are annuals. Their life span can be as short as just a few months and flowering is only a fraction of their life history. We would be remiss to mention the vast diversity of these plants, too. Over 2400 species of wildflowers are native to California. Naturally, their blooms are highly variable. From what we can tell, some species will bloom heavily in certain specific conditions, while others require completely different sets of circumstances to be dominant.
After a non-blooming year in 2013, the Antelope Valley was painted with color in 2014
              With such a short time to live in a year, they are not as dependent on the full rain year (July-June). Instead, annual wildflowers- especially in drier environments, such as ours- have the flexibility to respond to smaller pulses of rain. This is exactly what it looks like have experienced this year. Some research shows that the wildflowers of the San Joaquin Valley rely heavily on December/January precip. With almost no precipitation until March, the window for germination of SJV flowers pretty much closed. However, the March and April rains were favorable to the Antelope Valley blooms.
Pescado Creek had fabulous displays from March-May 2014
                Another important aspect of the wildflower bloom has to do with soils. It always comes back to soils. For the most part, the most impressive wildflower spots on Tejon Ranch occur on deep sandy soils, which are excessively well-drained. This means that when rain falls on these areas, it doesn’t stay locked up near the surface as would be true with clay soils. Instead, it just drains down into the water table and away from the wildflower seeds. Water, therefore, is only available to the wildflowers for short periods of time. When the rain falls at the right time for flower germination as it did in the Antelope Valley this year, plants are able to germinate. When the timing is right like this, it doesn’t take much water to have impressive results.   

Poppies persisted through may in the Antelope Valley. Photo courtesy of Chuck Noble
                 In comparison, many of the perennial plants and trees seem to be more dependent on the rain year as a whole. The manzanita (Arctostaphylos sp.), for instance is typically one of the  toughest, most drought-resistant genera in the state hardly bloomed at all in our neck of the woods this year. The few flowers I did see appeared small, slightly shriveled, and had all been attacked by either a wasp or beetle, evidenced by a discreet hole in each individual flower. Likewise, many of the ponderosa pines (Pinus ponderosa) on the ranch appear to be dying from bark beetles- typically a sign of drought conditions.


Photo courtesy of Chuck Noble
                Whether we wind up experiencing El Nino for the 2014-2015 rain year or not, we are unlikely to escape the throes of this current drought. However, if the timing is right for our rains, we might end up with a great wildflower year. At least that’s some form of consolation!

Hopefully spring 2015 will give nice flowers to enjoy throughout Tejon Ranch. Photo courtesy of Chuck Noble