A long time ago, before colonization, native bunch grasses thrived in California. Bunch grasses, such as squirreltail, or wild rye, Sandberg bluegrass, and Idaho fescue, were native perennial grasses that made good forage for local deer and antelope. Indigenous peoples also valued the grasses as valuable sources of food, medicine, and construction material, and maintained them through burning and tilling. With the arrival of Spanish soldiers and missionaries, grazing livestock was introduced to the area, along with new forage plants and weeds from the Mediterranean. Unfortunately, nonnative invasive grasses do not have same qualities as native grasses. While native perennial grasses smolder instead of igniting into flame, invasive annual grasses burn and allow fire to spread. Native perennial grasses also have deep roots that protect against erosion, while invasive annual grasses have shallow roots that are easily pulled out.
To the untrained eye, the Devil’s Garden is full of grass, but all grasses are different. Some are native perennials, others are invasive annuals. Some are edible, others are not. Hungry wild horses try bunches of Ventenata grass, but they are forced to spit it out because it is inedible. We find clumps of it, partially chewed, on the ground.
The native perennial grasses on the Devil’s Garden have higher forage values than invasive annual grasses and they stay greener longer into the season. Unfortunately, the native perennial grasses here are also less tolerant to disturbance; once disturbed, annual invasive grasses flourish in their place. More and more we are seeing invasive annual grasses replacing native perennial grasses on the Devil’s Garden. This conversion is not without consequence: as a result, there is less forage for wildlife and livestock, increased erosion, and greater fire frequency. Across California, over 99% of original grassland has been destroyed, making California grassland one of the most endangered ecosystems in North America.
Although invasive annuals such as Medusahead and Ventenata have contributed to this destruction, the act of introducing invasive species alone is not enough to change the entire ecosystem. Wild horses have greatly increased the impact of invasive plants on the land. Each and every one of the 3,900 horses on the Devil’s Garden are out on the land—eating, drinking, and loafing—7 days a week, 365 days a year. Horses do not walk on air. They leave their hoofprints on the ecosystem. Loafing results in patches of bare ground. Too many horses eating and drinking results in springs that have murky water and little vegetation. Too many mouths to feed on an already fragile land continues the conversion of nutritious native grasses into volatile invasives. More hungry horses result in more invasive grasses. More invasive grasses result in more fire, less forage, and less wildlife.
Poor forage from inedible grasses presents problems to all wildlife. Neither cattle, nor horses, nor elk, nor deer can find the nutritional value they need if the land turns to invasive annual grasses. This is a fact. For every spring damaged or land overgrazed, there’s an impact. Fewer elk, deer, pronghorn, fairy shrimp, sage grouse, or ibis. Every piece of the greater ecosystem requires management, whether by people or nature. We do not judge the quality of a spring by the presence of a single organism, but rather by the balance of all of them. We cannot maintain a healthy ecosystem without a careful balance. This is a problem for every interest group. If we care about horses, we must also care about the quality of the land that they live on.
Although cattle grazing occurs on the Devil’s Garden, it is a managed activity. Grazing permits allow cattle presence only on designated allotments, with restrictions that address livestock numbers, resource conditions, pasture rotations, and range improvement. At the end of the day, cows have a removal date. They are only grazing in monitored areas for select months out of the year. Permits are affordable, but require that ranchers maintain the land, for example, by repairing fences and monitoring stock tanks. Ranchers with grazing permits and Forest Service Range Specialists are the stewards of the land and they know it better than anyone else. They are the ones on the ground carefully monitoring land quality and use.
Ecological literacy is increasingly important in a day and age of public land battles. Land may be protected, but this does not preclude mismanagement, lack of management, or ecological decline. This unprecedented fire season is a strong reminder of the volatility of our land. Annual invasive grasses are responsible for a lot of this fragility. Annual grasses bloom early, turning from green to golden early in the season. High silica value in the grasses not only make them inedible, but also contribute to a slow decomposition rate and a build up of thatch layer. Between the dryness and thick residual clumps, one lightening strike and the Garden has plenty of fuel to start fire.
As the hot midafternoon sun begins to bake Devil’s Garden, it’s easy to be lulled into a trance. Silence settles over everything, making a single breeze seem incredibly loud. Walking miles across the Garden, we see more than just wild horses; we see the lava rock, juniper, and grasses that are home to so many species. For us it is hard to forget the greater picture of the land when we have our boots on the ground, amongst the grasses.
If you are interested in identifying grasses, I have attached a factsheet about annuals and perennials in the area.
Jenkins, VS. The Lawn: A History of an American Obsession. Washington, DC: Smithsonian Institution Press, 1994
Barry, Sheila et al. 2006. California native grasslands: a historical perspective—a guide for developing realistic restoration objectives. Grasslands, A Publication of the Native Grass Association. XVI (5): 7-11. http://ucanr.edu/sites/UCCE_LR/files/180943.pdf
California Native Grasslands Association
HilleRisLambers, Janneke et al. California Annual Grass Invaders: The Drivers or Passengers of Change? The Journal of Ecology 98.5 (2010): 1147–1156. PMC. Web. 27 Aug. 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936119/
Corbin, Jeffrey D and Carla M D’Antonio. Competition between Native Perennial and Exotic Annual Grasses: Implications for an Historical Invasion. Ecology 85.5 (2004): 1273-1283. Elkhorn Slough. Web. Aug. 2018 http://www.elkhornsloughctp.org/uploads/files/1108491037Corbin04.pdf