The Early Winter Prairie

This is a slightly edited reprint of my recent column at Bruce Bratton’s online weekly, to which I strongly suggest you subscribe.

Each season life in the coastal prairie changes in hue and character. The many inches of rain and the cold nights fashion the winter’s prairie now turning bright green with life that is gradually emerging from quiescence. Most annual plants have germinated; both annuals and perennials are growing slowly, the sward just 4 inches tall. The first flowers are blossoming, swales and pools abound with water, gophers throw muddy balls out their desperate breathing holes, and frost ices leaf edges, wilting tender new growth. Newborn calves follow their hungrily grazing mothers far to find enough food. Recreational trails through the prairies are frequently stirred muddy messes, destroying life while eroding ancient soils onto the few remaining prairies; bicyclists proudly sport their muddy equipment and clothes. Some signs of early winter prairie are ancient, while others are quite new.

Pop Goes the…

The first native coastal prairie wildflowers are related to broccoli and celery. Popweed and peppergrass are in bloom, relatives of broccoli. These are a tiny plants on shallow soil or along trails and the sparrow-grazed edges of shrubs…or on last year’s badger or gopher mounds. They have little white flowers with 4 petals that seem to twinkle almost like glitter brightening the prairie. After flowering, popweed makes elongated pods that dry and then ‘pop’ sending seeds further than you might think possible from such a small plant. The U.S. gave popweed to the rest of the world…as a pest! You are probably more likely to encounter both of these plants in sidewalk cracks or (popweed) in potted plants in town. I’ve had the unpleasant experience of getting popweed seeds in my eye more than once, a victim of the barrage of flinging seeds from one of these weeds hiding in a pot that I was moving in my nursery.

Who Spilled the Yellow Paint?

The other very early prairie wildflower is starting to show color. It is called ‘footsteps of spring.’ It has the botanical name Sanicula arctopoides – that last word of its name being a botanical pun: “arcto” for bear and “poides” for foot: barefoot (harr harr!) footsteps (guffaw!) of spring … chuckle-chuckle go those goofy botanists. The name seems right somehow if you think Spring leaves footprints when she arrives: the first really bright thing is this plant- the entire 8” across flat plant turns a surprisingly vibrant yellow framing similarly yellow clusters of flowers. These wildflowers tend to make patches on shallow-soiled ridgelets and outcrops in the prairie. And so, Spring seems to have left footprints with her arrival as she danced from ridge to ridge and across rocky pathways to awaken the prairie from its moist green wintery slumber.

Prairies as Wetlands

Many people are surprised that many of our prairies are wetlands, but if you wander out there now, you’ll become a believer. Coastal Terrace Prairies are on flat ground, mostly along the ancient wavecut and uplifted coastal terraces within a few miles of the coast. Housing and agriculture cover most of the first terrace, the one right above the ocean, but there are extensive prairies on the second, third, and fourth terraces. Look uphill and inland of Highway 1 on the North Coast, for instance. Being flat, coastal terraces don’t drain well and so are apt to have long periods of saturated soil, which is a key attribute of wetlands. In some places, there’s water pooled across the soil surface, but mostly the soil is just so wet that only plant species adapted to wetlands can survive. Walk across these areas and you’ll find shimmering rivulets snaking among the grasses downhill to add water to creeks. Along the edges of these squishy grasslands are seeps and springs oozing and gushing with plentiful water now and remaining green late into spring. In mima mounds and on rocky areas on the terraces, you might find vernal pools- small ephemeral ponds with chorus frog or toad tadpoles, festooned with curious alga and teeming with zooplankton.

Grassy Carpet

Looking broadly across the prairies, grasses are mostly what you see, but slimy things are hiding underneath. Perennial grasses, many of them million-year natives, are waking underground with only the slightest sign in their leaves; their tiny leaves are green, but their new white roots have already grown inches into the surrounding soil, quickly claiming as wide an area as possible. They compete against quicker-growing annual grasses, most of them here for just a few hundred years; these get tall faster and shade natives, inhibiting many native plants from establishing from seed. Without something like the ancient megafaunal grazing regimes, the non-native annuals create a (relatively) towering canopy protecting slugs and snails from bird. Under the grassy protection, mollusks devour the nutrient-rich native annual wildflower seedlings before they stand a chance.

Cows = Flowers

In some places, cattle graze the prairies, maintaining some semblance of the evolutionary disturbance regimes that coastal prairie diversity requires. Betting on a better yearling market, some local cattle ranchers set the bulls free among the heifers at a time that makes for calves right now. This is a difficult time for raising a calf – despite the slow growing lush grasses, there’s very little protein in those leaves. To make enough milk, the mothers must constantly graze, cropping the prairie short. Flocks of birds follow the cattle for the food they expose along the way. Research UCSC Professor Karen Holl and I have performed over the past many years has shown that cattle grazing in coastal prairie creates more abundant and more diverse native annual wildflowers than adjoining ungrazed areas. Cattle grazing, cow trails and the lightly driven ranch roads that accompany livestock also make for excellent habitat for the rarest of beetles…the Ohlone tiger beetle.

OTB

The Ohlone tiger beetle is emerging from its burrows now, bright metallic green-blue carapaces like finest jewels of our local prairies. This species is only found in a handful of grasslands near Santa Cruz. On sunny, warmer days, it forages for invertebrates along open trails in only the most diverse coastal prairies. Those sunny warm days also attract mountain bikers who cruise so swiftly along the trails – including miles of trails that are not sanctioned by the landowners – as to smash innumerable of these endangered insects. Just last week, a colleague visited the Mima Meadow at UC Santa Cruz to find many smashed, most probably killed by fast-moving bicyclists. The carcasses were on a trail not sanctioned for bicyclist use and even in an area the University, as a legal mandate from the US Fish and Wildlife Service, has set aside expressly for beetle conservation. If court cases from Florida are any precedent, the University could be held liable for the death of a federally protected endangered species…and penalized. Perhaps that’s what it would take for the University to enforce the protection of this area.

Muddy Mess

Perhaps one could understand a University’s difficulty in managing natural areas, but what about our State Park managers? Many of the coastal prairie trails at Wilder Ranch State Park once had Ohlone tiger beetles, but State Parks destroyed much of that habitat by dumping tons of gravel to ‘harden’ the trails as a ‘solution’ to allowing recreational access during the muddy winters. Parks staff subsequently decided to manage a small remnant area (successfully) for this endangered species. Even so, coastal prairie trails are a muddy mess these days, and use only stirs up that mud, loosening it so that it washes off into the surrounding grasslands. Those extra nutrients spur weedy growth and destroy wildflowers. Meanwhile the incising and eroding trails serve to drain the surrounding wet meadows, an alteration that also degrades the habitat. Shame on users and managers alike for destroying eons of evolution and a legacy for future generations! If you see the (rare) ‘trails closed’ signs…which are almost always (if present) defaced and thrown aside…please prop them back up and go for a forest walk, instead.

One comment

  1. Isn’t most of the pop-weed the non-native Cardamine hirsuta? It came onto my property I believe from plant nursery pots. Wasn’t always here. Awful hard to get rid of. The native species is Cardamine oligosperma. I wouldn’t mind having it if it’s native. I’ve been trying to get a handle on the differences, in ways I can actually see. One difference is number of stamens: nearly always four stamens for C. hirsuta and six for C. oligosperma.

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