California Native Oaks: Past and Present

International Oaks International Oaks other hand, black oak acorns often respond display its characteristic bark and growth favorably to a period of cold stratification with form as well as the cycle and quality of mast, rapid germination. the acorn crop. California Native Oaks: Seedling oaks are temporary. Huge popula The life of a tree can be divided into three tions of seedlings come and go following good stages: young, mature and declining. Young seed crops. Seedlings suc Past and Present cumb to a variety of problems including drought, herbivory (both above and below-ground) and fire. Although physiologi by James R. Griffin and Pamela C. Muick call y equipped to sprout University of California at Berkeley, USA after above-ground dam age, very few seedlings survive and grow to the he fossi l record indicates that oaks have been in California for at next stage of maturity, the least the past ten million years. Relat1ves of most of the Cahforn1a short sapling stage. T oaks have been found in late Miocene sediments deposited five Short sapling oaks have to thirteen million years ago. an increased likelihood to There are approximately sixty species of oaks in the United States, survive to adulthood. Short and an estimated three hundred worldwide, primarily in the Northern saplings, under four and Hemisphere. Ten tree and eight shrub species of Quercus grow in one-half feet in height, California. California species fall into three different subgenera: the have a woody stem and a Photo by David Cavagnaro white oaks, Lepidobalanus (now Section or Subgenus Quercus); the well-developed root sys- Huck/eben yoak (Quercus vacciniifolia). intermediate oaks, Protobalanus; and the black oaks, E1y throbalanus tem which serves as a (also known as Section Lobatae of Subgenus Quercus). The prefix reservoir of energy. Short saplings sprout trees usually have a strong ability to sprout Erythro is derived from the Greek word for red. Generally, taxonomists readily after injuries from fire, drought or from the base after injury. Mature trees may and foresters refer to the Erythrobalanus group as red oaks. However, in browsing, and may be kept in a hedged sprout from the stumps of broken branches. California and the northeastern United States, this group is known as condition for decades. Only after the sapling's However, the ability of mature trees to sprout black oaks. The local usage probably arises from Q. kelloggii (California leader reaches above the deer browse line does from the stump is more variable. For instance, black oak), a species in the Erythrobalanus that is physically similar to the sapling proceed to the next level of blue oak (Q. douglasii) and Garry or Oregon the red oaks in the eastern part of the United States. Hybridization, which maturity, the tall sapling stage. oak (Q. garryana) appear to stump sprout well is naturally restricted to crosses within a subgenus, has result in eleven Tall saplings, greater than four and one-half to mid-size classes, while valley oak (Q. named hybrids and ten unnamed hybrids. feet (above the browse line), gain height and lobata) loses this ability earlier. The black and girth rapidly. At this stage, after top death due intermediate oaks, as well as most of the shrub Oak life cycle to burning, they may regain their previous species, sprout vigorously after fire. Oaks are monoecious, bearing male catkins and female flowers upon stature within a few years. Saplings gain height Disease plays a large part in the life of the the same individual plant. Flowers are wind pollinated, and acorns before adding girth, and then develop into the adult oak. To quote the British ecologist M. J. mature in either one- or two-year cycles. The acorns of the white oaks next stage of maturity, young trees. Penistan, in his paraphrase of Dryden: "The characteristically mature in the fall of the same year the flowers Tree status can be considered the beginning monarch oak, the Patriarch of trees, springs bloomed. In contrast, most of the black oaks exhibit delayed ferti li zation of the productive stage of an oak's life. rising up, then spreads by slow degrees; one similar to some of the pines; acorns mature in fall of the second year. Although timing and triggering mechanisms hundred years he grows, one more he stays Cali fornia white oak acorns do not require a period of dormancy and for sexual maturity are unclear, root and shoot supreme in state, then in one more decays." generally germinate in the fall or winter after dropping. In fact, emerging mass, as well as vigor and crown position, are roots are visible on some blue oak acorns while still on the tree. On the components. As an oak matures, it begins to contd. on pg . 42 Page 40 No.1 Republication I March 1999 No . 1 Republication I March 1999 Page 41 International Oaks International Oaks California Native Oaks . bers of gold miners also • • had a lasting and negative effect on California oaks. contd. from pg. 41 Sonora and Auburn are two classic examples of foothill sixty-seven different types of oak habitat. oak woodland gold-mining Wildlife and oak habitats Oaks dominate or co-dominate in twenty-five communities. The Gold During their long history in California, oaks natural plant communities, and are character Rush also adversely af have evolved strong interrelationships with istic members of forty-three others. fected the Central Valley wildlife. Today, an estimated 5000 species of oak savannas where agri insects use oaks, and 1000 are dependent upon Humans and oaks culture rapidly developed oaks. Approximately 170 species of birds use California's human history is inextricably to support the growing oaks at some point in their life cycle. Fifty interwoven with its landscape and vegetation. population of gold miners. eight species of li zards, snakes and amphibians Over millennia, native Californians developed Even some mining ven are associated with oak habitats. One hundred many uses for oaks. Acorns were a major item tures well up into the Photo by David Cavagnaro five species of mammals, including most of the in their diet; acorns were also important for the conifer forests seriously game species in the state, use the oak resource. animals they used for food. Many native affected the Central Valley CoasT live oak (Quercus agrifolia). Interactions between diseases, wildlife American cultures acknowledged their depen riparian oak forests. For (including feral hogs), and introduced annual dence upon oaks through ritual and legend. example, massive hydraulic mines above Before we enter the next century, Californians plants are avenues of research being explored The near extinction of these indigenous Nevada City led to long-term flooding should critically evaluate the role of oaks in by contemporary researchers. However, peoples from their ancestral oak populations problems in the lower Sacramento Valley. modern society and how these ancestral research efforts are uneven across the species marked a loss of a sophisticated understanding Siltation from the Malakoff Diggings and landscapes can be preserved amid rapid in the state. about oak stewardship. Today we cannot fully associated placer mines raised the Yuba River population growth and land speculation. Approximately ten million acres of Califor recover the loss of oak management lore that bed on the valley floor well above the its Although it is difficult to imagine California nia are habitat to the nineteen native species of passed away with these people. normal level. Graphic reminders of this devoid of oaks, with treeless foothills or oak. The California Department of Fish and When Franciscan missionaries arrived in problem still occur in wet years, when the coastal landscapes, the history of Europe and Game Natural Diversity Data Base recognizes 1769 they often located missions in oak Yuba River floods Marysville and Yuba City. the British Isles gives us pause. At one time woodlands. These missions, Riparian oaks in the Central Valley were Ireland, England and Wales were almost and the associated Mexi first cut to fuel steam boats. As agriculture entirely covered with trees-mostly oaks. For can ranchos, had a pro expanded, there was increasing pressure from many Californians, blue gums and other exotic found impact on oak wood powerful farming interests to control flooding. trees are not an acceptable alternative for our lands. The introduction of Much of the riparian forest, which included native oaks. aggressive Mediterranean impressive valley oaks, was cleared following annual grasses and forbs various flood control projects. Kenneth Historic glimpses of California Oaks along with Mex ican cattle Thompson, a great student of Sacramento Many California explorers and botanists changed forever the nature Valley riparian forests, wrote that "with the recorded observations of the oak-filled of the California grassland coming of white man the pristine vegetation landscapes they encountered. Their comments and oak woodlands. How (of the Sacramento Valley) was modified with remind us of the rich diversity of California many current California a rapidity and completeness unmatched in oaks, ranging from low, arid Mojave Desert residents know, or care, other parts of the United States." slopes to high, wet ridges in the Klamath that much of the green Throughout California, major areas of oak ranges. woodland understory in woodland remain; but locating healthy, George Vancouver, commander of the spring has been here for mature, or young regenerating oak stands, English ship Discovery, described valley oaks in the Santa Clara Valley in 1792: "For about Photo by David Cavagnaro less than two centuries? unthreatened by agricultural or urban develop ment, is becoming increasingly difficult. Ca/i/(ml.ia black oak (Quercus kelloggii). The arrival of vast num- contd. on pg. 44 Page 42 No.1 Republication I March 1999 No.1 Republication I March 1999 Page 43 International Oaks International Oaks and dusty trails, although for a few brief days Castroville: "On the uplands and low hills east California Native Oaks ..

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