Conservation Grazing for Grassland Diversity

My dissertation research, others’ research, and years of observation supports a need to seriously consider conservation grazing as a tool for managing the incredibly diverse grasslands of our region.

Ancient Habitat

We owe the existence of almost every bit of our local grasslands to human management of ecological disturbance regimes. For millions of years, California’s grasslands co-evolved with megafauna. 20,000 years ago, the prairies near Santa Cruz would have had herds of mastodon, mammoth, bison, ground sloth, elk, pronghorn, as well as camel and horse relatives. There were probably mastodon and mammoth trails the size of highways; like their African kin, these critters pushed over trees when drought or fire deprived them of ground-based forage.

The biomass of those herbivores was enough to evolve some amazing predators: saber tooth cats and their bigger kin the scimitar cats, a lion very close to the African lion, wolves, short-face bears, grizzly, jaguar, coyote and cougar.

About 15,000 years ago, most of that fauna disappeared, but the native peoples were stewarding the grasslands with frequent fire. Fires kept the grasslands open.

Without fire or grazing, our coastal grasslands turn to shrublands and the shrublands to forest.

Here Come the Shrubs!

First comes the coyote bush, seeds blown on the wind way downstream. First one shrub, then the next and soon there is more coyote bush than grass. As the shrubs thicken, coast live oaks take root, and they look like shrubs for years and years until they get wide enough that the deer can’t reach the center shoot, and that becomes a tree. Meanwhile, while oaks get shrubbier, here comes the poison oak and their injector friends the blackberry vines. Now, things are getting pretty impenetrable. After about 15 years, we start to see some more diversity: coffeeberry, California sage, sticky monkeyflower, honeysuckle, and others.

All the coastal prairies that aren’t on nearly pure, soil-less rock disappear to shrubs after 15-40 years. There are fencelines and aerial photos aplenty to show you this.

And Next…the Onset of Trees

As the shrub community closes in, the tree seedlings escape deer browse. Coast live oaks and Douglas fir rocket up from the shrub layer. Some toyon start getting tree like, too. Madrones join in.

Check out a mixed hardwood/Douglas fir forest next time you happen across one. Look at the understory and see if you can see shrub skeletons- they are likely there as a reminder from whence the trees emerged.

So, What’s the Problem? Trees are GOOD! “never enough trees….” (sigh)

California’s grasslands support the vast majority of rare plant and animal species. Globally, grasslands have been underappreciated for their diversity and function. California’s coastal prairies are one of the top ten most endangered habitats in the US. These grasslands have been converted to urban areas more than any other plant community. I bet we are still more likely to see grasslands developed locally than any other habitat type. For instance, the meadows at UC Santa Cruz are constantly under threat.

Many of your favorite wildlife species love our meadows. Deer, bobcat, fox, weasel, badger, eagle, hawk, kite, falcon, kestrel, owl, and tule elk are grassland friends. Predators require the vast production of mice, voles, gophers, and moles that grasslands create.

Even if wildlife aren’t your thing (and you’d be very much in the minority there), you might appreciate the functions that grasslands play. Grasslands can break up and cool down wildfires that would otherwise move catastrophically across the landscape. Prairies can be huge carbon and water sponges, soaking up climate change pollutants and soaking in precipitation to replenish groundwater and meter out rains to keep springs, creeks, and rivers flowing later in the season. Many folks love grasslands for recreation: picnics, lying in the sun, walking through them – all worthwhile and important activities. Grassland openness makes way for many of those favorite views. Masses of spring wildflowers create giddy laughter and attract tourists.

Oh, and grasslands raise cows…

Cows on the Prairie: Moooo!

After the genocide of native peoples, after they were driven from their ancestral homes, the prairies would have disappeared were it not for cows. The next era of grassland disturbance was the ranching era. Yes, there was a prohibition against fire. No, there were no limits to grazing. The early ranchers put way too many cows on the landscape: there were famous drought incidents early in California where dead cows littered the landscape. There is a huge slug of sediment in the Monterey Bay that is thought to be erosion from poor grazing and agricultural practices of that era.

Gradually, we have adapted cattle management to this variable climate. Our grasslands create beef. Some of that is grassfed/grass finished beef where cattle live their entire lives on open range. That beef production keeps the meadows open. And the fact that cows make money keeps the land grazed.

What About Elk?

Tule elk graze much like cows, and so would keep the meadows open if they could. Studies at Point Reyes where tule elk roam show that that species does about the same thing as cows: they keep open areas where grasses and wildflowers flourish.

The trouble is, we don’t have any elk on the Monterey Bay. Why not?

There are tule elk just east and south of us- not very far if they wanted to get here. But, apparently tule elk don’t like going through forest…not like their close relatives Roosevelt elk. At the same time, some of those tule elk already crossed 101 down along Coyote Creek in the Coyote Valley south of San Jose, but they turned back. Those elk are closer than the ones across 101 from Prunedale or the ones at Ft. Hunter Liggett. If the tule elk crossed the highway in Coyote Valley and kept going westward, they would have to get around a bunch of houses here and there, but they’d have lots of good grasslands across the east range of the Santa Cruz Mountains. If they tried going more west, there isn’t a good chance that they would find a grassy corridor to our coast side grasslands. So, it will be many, many years until we get elk, unless someone finds a way to truck them here, and then they’d have to want to stay. Meanwhile, let’s find a way to support the types of grassland management we need to keep our meadows open.

-this post originally a part of Bruce Bratton’s web blog, where I often contribute columns of ecological information from the Monterey Bay region.