| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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a trail less traveled Jughandle State Reserve If you stand on a sea bluff almost anywhere on California's wild coast, you can't help but notice the forces that are constantly reshaping the shore. Cliffs crumble, waves smash against rocks that not long ago were under the ocean. You can almost hear the tectonic plates push and grind against each other, lifting the continent's edge. Nowhere is this process more clearly visible than at Jughandle State Reserve, five miles north of Mendocino. Here along a steep four-mile-long watershed, you can actually see, step by step, how land has emerged from the ocean during the past half million years. A 2.5-mile trail leads from the seacliffs up a five-step ecological staircase. Each wave-cut step is roughly one hundred feet higher and 100,000 years older than the one below. Each was carved into the dark sandstone bedrock as the sea level rose after each ice age. When the polar ice thickened again and glaciers advanced, the sea level dropped and the waves covered the new terrace with gravel, sand, and clay. Meanwhile, this stretch of coast was steadily rising, at a rate of about one inch per century. As ice ages came and went, the steps moved up as a single unit, like an escalator. The youngest terrace, which now extends about a mile inland from the sea bluffs, was a sand and gravel beach 100,000 years ago. It will, in turn, be displaced by the terrace now forming underwater. The Jughandle Ecological Staircase is considered the most complete demonstration of soil evolution in the world. But you don't have to be a scientist to follow the story it tells. Pick up an interpretive leaflet at the kiosk in the parking area (or get a map at Jughandle Farm across the road), and walk the trail. The trail begins along the bluff, leads down into the creek bed and then onto the east end of the first terrace. Over the next half mile the trail passes from prairie grass to conifer forest, and eventually to the pygmy forest, where stunted trees with trunks no bigger than a person's forearm can be more than a hundred years old. The second terrace presents a climax conifer forest of Sitka spruce, lowland fir, and bishop pine, crowded with trees. But drainage is poor and there are places where an orange-brown hardpan has formed as the acidic soil combines with silica. This layer continues to thicken as it moves upward through the terraces. The steep trail that leads over rolling terrain to the third terrace passes through a dense forest of redwoods, firs and hemlock. These tall trees grow on the eroding remnants of ancient dunes, in soil built by pine needle and leaf compost. The trail emerges into what seems, at first, to be a clearcut forest. Then you notice the trees, no higher than your knees, and feel like Alice after eating her mushroom in Wonderland. This is the pygmy forest, where few trees can survive, and even the dwarf redwoods are no more than six feet high, and have red-brown needles. The plants here can no longer penetrate the hardpan. It's as though the entire forest has been planted in a pot with no hole on the bottom. The fourth and fifth terraces repeat the conditions of the third except that the trees are still smaller. On the west side of the remnant dunes are sphagnum bogs, where the insect-eating sundew plant grows. The trail does not continue to these last two terraces, however. Instead it loops back through the Jackson Forest Pygmy Forest Reserve. Beside a newly built boardwalk is a cross-section of pygmy forest soil alongside a drainage ditch. The humus is less than one inch thick, underlain by a foot of white quartz podsol, then two feet of sandstone-like hardpan. Below the hardpan, out of sight, is a ten-foot layer of beach sand and gravel atop graywacke sandstone bedrock--the same soil profile as in today's seacliffs.
He would start on the seacliff above the mouth of the creek by pointing out that the sand on the beach below was whiter than sand on beaches nearby. It had been washed down from the pygmy forest and had been bleached in the course of the past half million years. Now it was about to begin another half-million-year return journey upward. Then, moving briskly in his long-legged stride, he would lead the group upstream, explaining what lay before them in metaphors that spoke to everyone. If this were a city, he would say, reaching the third terrace, these redwoods would be the very rich, for they have the best of everything. They grow in good, well-aerated soil, where the drainage is excellent, and nutrients plentiful. They benefit from the work of the waves, which brought the sand that formed these old dunes they grow on, and from the organic matter washing down from the higher terraces. In contrast, the pygmy forests grow in the poorest neighborhoods, where nearly everyone is malnourished and those who survive tend to grow up stunted. Had these same trees taken root on one of the lower terraces, some would now loom high above us. Some weeks ago, I walked the staircase with Tina Fabula, assistant ecologist with the State Parks Department, who wanted to check on some trail work by the California Conservation Corps. A few steps west of the parking area, through a pine grove and past a picnic table, and we were in the dazzling light, looking out across the grassland, over the bluffs and toward the ocean horizon. Directly ahead, two white plumes signaled that the gray whales were migrating. To the north and the south, nothing impeded the views across the coastal terrace. Soon it would be spring again, and this entire expanse would once more be covered with wildflowers. Fabula pointed out the blackberry tangle where a northern harrier nests, and the place where Alaska meets Mexico, represented by a Sitka spruce growing next to a bishop pine. Only here will you see these trees side by side. We walked upstream, following geological time zones. When we returned three hours later, the sky was glowing green and red in the sunset. The Ecological Staircase is in good hands, though more hands would help. State Parks lacks the money to keep a ranger here to continue the walks Olmsted began. Rasa Gustaitis is Editor of Coast and Ocean. |
Spring 1997
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