Mojave Plants Flee Climate Change

DSC_0754Second in our series of reports on the most obvious effects of climate change on public lands in California
At 1,310-acre Devil’s Punchbowl, part of Angeles National Forest in the Mojave High Desert region of the state, casual visitors see plants with lifespans of up to 1,000 years dying.  Brown color supplants green along the park entrance road.  They see it in the parking lot and at trailside.

“There used to be junipers all over there,” says David Numer of the entrance road flora.  Numer, superintendent of Devil’s Punchbowl, has observed the local flora for 42 years and cites a “15-20-year” dry period causing plant migration upslope into cooler sections of the park.  Devil’s Punchbowl is located on a Mojave Desert mountainside, elevation 4,750 feet.

This is one of the most accommodating of parks for tourists curious about climate change.  Numer points to a a tree trunk cross-section at the nature center.  Thin rings indicate dry years, wide rings wet years.  This is formal Exhibit A of climate change, but informal exhibits abound.

A dead pinyon pine ( Pinus monophylla ) at the center of the parking lot vista appears in countless photos.  David explains that bark beetles caused this death but that climate change brought the bark beetles.  Excessive heat causes a reduction in pine sap levels.  Bark beetles no longer become trapped in the sticky sap.  They prey unmolested on the tree.  “Bark beetles actually eat the cambium layer of the tree.  On dead pinyon pines, you find beetles, but not the bark beetles, which have already moved to the next tree.”

Hikers immediately encounter dead manzanita shrubs.  They fringe the trail into the “punchbowl,” a canyon rimmed with spectacular rock formations.

Climate change at the Punchbowl results in a migration of animals inverse to that of plants.  Bighorn sheep and mule deer abandon surrounding high country springs as they dry up.  They resort to the relatively lower elevations of the park itself.

Since water flows downhill, springs at higher elevations disappear first.  The water, upon reaching the gentler angle of slope, spreads outward.  A life-sustaining aquifer develops there.  The hydrological refuge now allows unusual views of wildlife attracted to browse plants supported by the aquifer.  “We see bighorn sheep at Devil’s Chair,” a popular vista in the park, Numer notes.

The life response to heat and dryness here is elevational, a flight to moisture zones at different levels.  This reaction leads to potential species eradication.  What happens when the junipers and pinyon pines migrate into bare rock?  The life of Devil’s Punchbowl has paralleled  human life since the beginning and demonstrates only one of many ways that both are changing.2015-06-17 23.04.03











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