When I am out hiking this time of year I am constantly reminded, especially as I look at the golden hills of California, how much the landscape has been altered since the Europeans first arrived in the New World. 500 years ago the sunny, baked hills above Livermore would have been greenish not yellow. Perennial bunch grasses with taproots penetrating down 18 feet took full advantage of permanent groundwater. And the plants would continue to photosynthesize throughout the extended drought of our Mediterranean climate maintaining their vibrant living color until the first invigorating rains of the autumn arrived. Grazing animals certainly existed here 20,000 years ago and impacted the grasslands. There would have been mastodons, giant ground sloths, as well as modern animals such as Tule elk, pronghorn, and black tailed deer. When the Native Americans arrived they also encouraged the grassland by periodically burning it. Grass has evolved to not only tolerate but often thrives under continued grazing and periodic fire. Agronomists suspect that some of our native grasses regularly live to 200 years and perhaps as long as 1000 years!
The most significant change in California’s biodiversity was the transformation of these bunchgrass-dominated ecosystems to the near total replacement by Eurasian annual grasses. The Spaniards brought horses, cattle, sheep, and their attendant European barnyard weeds into California in the late 1700s. These aggressive, non-native, annual grasses could germinate, flower and fruit in the short growing season and were already adapted to the heavy grazing of domesticated animals. Wherever livestock was introduced, the new grasses quickly outcompeted and replaced the perennials in an incredibly short period of time. This occurred so rapidly that there were basically no scientifically trained witnesses to record the startling conversion.
99% of the native grasses in California are gone. California’s early settlers transformed this place in so many ways – culturally, economically, ethnically – and they even gave us our golden hills.
This is Michael Ellis with the Perspective.