Quercus tomentella, the island oak, island live oak, or Channel Island oak, is an oak in the section Protobalanus. It is native to six islands off the coast of California and to one Mexican island: five of the Channel Islands of California plus Guadalupe Island. Island oak is a tree growing up to 20 metres in height; the mature tree has a grayish to reddish brown trunk with furrowed bark. The twigs are reddish and covered in woolly hairs; the leathery leaf blades are concave and are an oblong lance shape or oval with pointed or rounded tips. The edges are toothed; the upper surfaces are dark green and hairy when new, losing the hairs over time. The undersides are gray-green and coated in woolly hairs, they are 7 to 10 centimeters long, sometimes up to 12 cm. The acorn grows singly or in pairs; the cup is up to 3 centimeters wide. The nut is up to 3.5 centimeters with a rounded tip. Island oak hybridizes with canyon live oak; this species is a relict. Though it is now limited to the islands, it was once widespread in mainland California, as evidenced by the many late Tertiary fossils of the species found there.
It was found that in Santa Catalina Island, part of Channel Islands of California, there was a high genetic variability in a population of Q.tomentella, but this variation was not evenly distributed. The island oak was listed as an endangered species by the International Union for Conservation of Nature; the species is threatened by overgrazing. The most rapid declines have occurred on Guadalupe Island; the trees there are no longer reproducing. Feral goats have been abundant on the island for at least 150 years; the animals have caused extensive soil erosion. Fenced enclosures have been helpful in the early recovery of some of the local flora. Calflora Quercus tomentella in the CalPhotos Photo Database, University of California, Berkeley photo of herbarium specimen at Missouri Botanical Garden, collected in Guadalupe Island in 1875
Pinus quadrifolia, the Parry pinyon, is a pine in the pinyon pine group native to southernmost California in the United States and northern Baja California in Mexico, from 33° 30' N south to 30° 30' N. It occurs at moderate altitudes from 1,300 metres to 1,800 metres as low as 1,200 metres and as high as 2,500 metres, it is scarce and scattered in this region, forming open woodlands mixed with junipers. Other common names include nut fourleaf pinyon pine. Pinus quadrifolia is a small to medium size tree, reaching 8 to 15 m tall and with a trunk diameter of up to 40 cm more; the bark is thick and scaly. The leaves are in fascicles of 4–5, moderately stout, 2.5–5.5 cm long. The cones are globose, 4–5.5 cm long and broad when closed, green at first, ripening yellow to orange-buff when 18–20 months old, with only a small number of thick scales, with 5–10 fertile scales. The cones open to 5 to 7 cm broad when mature; the seeds are 10–14 mm long, with a thin shell, a white endosperm, a vestigial 1–2 mm wing.
The jay, which uses the seeds as a food resource, stores many of the seeds for use, some of these stored seeds are not used and are able to grow into new trees. The Parry pinyon hybridises with single-leaf pinyon where their ranges meet in southern California and northern Baja California. Hybrids are distinguished by intermediate features, with needles fascicles of 2–3 with some stomata on the outer surface, it has been suggested by some botanists that the holotype specimen of P. quadrifolia is itself from a hybrid. However, there is no proof that these specimens are genetically'purer' than the original type specimen, few botanists accept P. juarezensis as other than a synonym of P. quadrifolia. Despite the ease of hybridisation with single-leaf pinyon, Parry pinyon is genetically more related to the Johann's pinyon and Potosí pinyon, despite being separated from them by well over 1,000 km; the edible seeds, pine nuts, are collected throughout its range, though it is much less important than Colorado pinyon for the crop.
Parry pinyon is occasionally planted as an ornamental tree and sometimes used as a Christmas tree. Due to the limited distribution of the species, the seeds of the Parry pinyon are not gathered commercially, they are more consumed by birds and other mammals. The Cahuilla tribe of southern California used the resin to make a face cream used by girls to prevent sunburn; the nuts were useful as well. For the Cahuilla, the nuts were given to the babies to eat as an alternative from breast milk and were grounded mixed with water as a beverage; the nuts were roasted and made into mush. They were important to the Cahuilla as a trade item with neighboring tribes; the pine needles and roots were used as material for basketry and the bark was a reliable substance for making the roofs of houses. The resin was a glue for mending pottery and reattaching arrowheads to the arrow shafts; the wood was burnt for firewood and incense, since it had high combustibility and it gave a pleasant smell. The Diegueno ate the nuts, but the seeds as well.
Photo of cones. Pinetum.org
An ecoregion is an ecologically and geographically defined area, smaller than a bioregion, which in turn is smaller than an ecozone. All three of these are either greater than an ecosystem. Ecoregions cover large areas of land or water, contain characteristic, geographically distinct assemblages of natural communities and species; the biodiversity of flora and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are large areas of land or water where the probability of encountering different species and communities at any given point remains constant, within an acceptable range of variation. Three caveats are appropriate for all bio-geographic mapping approaches. Firstly, no single bio-geographic framework is optimal for all taxa. Ecoregions reflect the best compromise for as many taxa as possible. Secondly, ecoregion boundaries form abrupt edges. Thirdly, most ecoregions contain habitats. Biogeographic provinces may originate due to various barriers.
Some physical, some climatic and some ocean chemical related. The history of the term is somewhat vague, it had been used in many contexts: forest classifications, biome classifications, biogeographic classifications, etc; the concept of ecoregion of Bailey gives more importance to ecological criteria, while the WWF concept gives more importance to biogeography, that is, distribution of distinct biotas. An ecoregion is a "recurring pattern of ecosystems associated with characteristic combinations of soil and landform that characterise that region". Omernik elaborates on this by defining ecoregions as: "areas within which there is spatial coincidence in characteristics of geographical phenomena associated with differences in the quality and integrity of ecosystems". "Characteristics of geographical phenomena" may include geology, vegetation, hydrology and aquatic fauna, soils, may or may not include the impacts of human activity. There is significant, but not absolute, spatial correlation among these characteristics, making the delineation of ecoregions an imperfect science.
Another complication is that environmental conditions across an ecoregion boundary may change gradually, e.g. the prairie-forest transition in the midwestern United States, making it difficult to identify an exact dividing boundary. Such transition zones are called ecotones. Ecoregions can be categorized using an algorithmic approach or a holistic, "weight-of-evidence" approach where the importance of various factors may vary. An example of the algorithmic approach is Robert Bailey's work for the U. S. Forest Service, which uses a hierarchical classification that first divides land areas into large regions based on climatic factors, subdivides these regions, based first on dominant potential vegetation, by geomorphology and soil characteristics; the weight-of-evidence approach is exemplified by James Omernik's work for the United States Environmental Protection Agency, subsequently adopted for North America by the Commission for Environmental Cooperation. The intended purpose of ecoregion delineation may affect the method used.
For example, the WWF ecoregions were developed to aid in biodiversity conservation planning, place a greater emphasis than the Omernik or Bailey systems on floral and faunal differences between regions. The WWF classification defines an ecoregion as: A large area of land or water that contains a geographically distinct assemblage of natural communities that: Share a large majority of their species and ecological dynamics. According to WWF, the boundaries of an ecoregion approximate the original extent of the natural communities prior to any major recent disruptions or changes. WWF has identified 867 terrestrial ecoregions, 450 freshwater ecoregions across the Earth; the use of the term ecoregion is an outgrowth of a surge of interest in ecosystems and their functioning. In particular, there is awareness of issues relating to spatial scale in the study and management of landscapes, it is recognized that interlinked ecosystems combine to form a whole, "greater than the sum of its parts". There are many attempts to respond to ecosystems in an integrated way to achieve "multi-functional" landscapes, various interest groups from agricultural researchers to conservationists are using the "ecoregion" as a unit of analysis.
The "Global 200" is the list of ecoregions identified by WWF as priorities for conservation. Ecologically based movements like bioregionalism maintain that ecoregions, rather than arbitrarily defined political boundaries, provide a better foundation for the formation and governance of human communities, have proposed ecoregions and watersheds as the basis for bioregional democracy initiatives. Terrestrial ecoregions are land ecoregions, as distinct from marine ecoregions. In this context, terrestrial is used to mean "of land", rather than the more general sense "of Earth". WWF ecologists divide the land surface of the Earth into 8 major ecozones containing 867 smaller terrestrial ecoregions; the WWF effort is a synthesis of
California chaparral and woodlands
The California chaparral and woodlands is a terrestrial ecoregion of lower northern and southern California and northwestern Baja California, located on the west coast of North America. It is an ecoregion of the Mediterranean forests and scrub Biome, part of the Nearctic ecozone; the California chaparral and woodlands ecoregion is subdivided into three smaller ecoregions. California coastal sage and chaparral ecoregion: In southern coastal California and northwestern coastal Baja California, as well as all the Channel Islands of California and Guadalupe Island. California montane chaparral and woodlands: In southern and central coast adjacent and inland California, covering some of the mountains of: the Coast Ranges. California interior chaparral and woodlands: In central interior California surrounding the California Central Valley cover the foothills and the Transverse Ranges and Sierra Nevada. Most of the population of California and Baja California lives in these ecoregions, which includes the San Francisco Bay Area, Ventura County, the Greater Los Angeles Area, San Diego County, Tijuana.
The California Central Valley grasslands ecoregion, as well as the coniferous Sierra Nevada forests, Northern California coastal forests, Klamath-Siskiyou forests of northern California and southwestern Oregon, share many plant and animal affinities with the California chaparral and woodlands. Many botanists consider the California chaparral and woodlands, Sierra Nevada forests, Klamath-Siskiyou forests, Northern California coastal forests as a single California Floristic Province, excluding the deserts of eastern California, which belong to other floristic provinces. Many Bioregionalists, including poet Gary Snyder, identify the central and northern Coast Ranges, Klamath-Siskiyou, the Central Valley, Sierra Nevada as the Shasta Bioregion or the Alta California Bioregion; the ecoregion includes a great variety of plant communities, including grasslands, oak savannas and woodlands and coniferous forests, including southern stands of the tall coast redwood. The flora of this ecoregion includes tree species such as Gray or foothill pine, Scrub oak, California buckeye, the rare Gowen cypress, the rare Monterey cypress, a wealth of endemic plant species, including the rare San Gabriel Mountain liveforever, Catalina mahogany, the threatened most beautiful jewel-flower.
Hesperoyucca whipplei, colloquially known as Chaparral Yucca, is commonplace throughout the lower elevations of the climate zone. Species include the California gnatcatcher, Costa's hummingbird, coast horned lizard, rosy boa. Other animals found here are the Heermann kangaroo rat, Santa Cruz kangaroo rat, the endangered white-eared pocket mouse. Another notable insect resident of this ecoregion is the rain beetle It spends up to several years living underground in a larval stage and emerges only during wet-season rains to mate. Chaparral, like most Mediterranean shrublands, is fire resilient and burned with high-severity, stand replacing events every 30 to 100 years. Native Americans burned chaparral to promote grasslands for textiles and food. Though adapted to infrequent fires, chaparral plant communities can be exterminated by frequent fires with climate change induced drought. Today, frequent accidental ignitions can convert chaparral from a native shrubland to nonnative annual grassland and drastically reduce species diversity under global-change-type drought.
The region has been affected by grazing, logging and water diversions, intensive agriculture and urbanization, as well as competition by numerous introduced or exotic plant and animal species. Some unique plant communities, like southern California's Coastal Sage Scrub, have been nearly eradicated by agriculture and urbanization; as a result, the region now has many endangered species, including the California condor. World Wildlife Fund: California Chaparral and Woodlands ecoregion California Chaparral Institute website California Coastal Sage and Chaparral images at bioimages.vanderbilt.edu California Interior Chaparral and Woodlands images at bioimages.vanderbilt.edu — California Montane Chaparral and Woodlands images at bioimages.vanderbilt.edu —
An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae. There are 600 extant species of oaks; the common name "oak" appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta and the Casuarinaceae. The genus Quercus is native to the Northern Hemisphere, includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia and North Africa. North America contains the largest number of oak species, with 90 occurring in the United States, while Mexico has 160 species of which 109 are endemic; the second greatest center of oak diversity is China, which contains 100 species. Oaks have spirally arranged leaves, with lobate margins in many species. Many deciduous species are marcescent. In spring, a single oak tree produces small female flowers; the fruit is a nut called an oak nut borne in a cup-like structure known as a cupule. The acorns and leaves contain tannic acid, which helps to guard from insects.
The live oaks are distinguished for being evergreen, but are not a distinct group and instead are dispersed across the genus. The oak tree is a flowering plant. Oaks may be divided into two genera and a number of sections: The genus Quercus is divided into the following sections: Sect. Quercus, the white oaks of Europe and North America. Styles are short; the leaves lack a bristle on their lobe tips, which are rounded. The type species is Quercus robur. Sect. Mesobalanus, Hungarian oak and its relatives of Europe and Asia. Styles long; the section Mesobalanus is related to section Quercus and sometimes included in it. Sect. Cerris, the Turkey oak and its relatives of Europe and Asia. Styles long; the inside of the acorn's shell is hairless. Its leaves have sharp lobe tips, with bristles at the lobe tip. Sect. Protobalanus, the canyon live oak and its relatives, in southwest United States and northwest Mexico. Styles short, acorns mature in 18 months and taste bitter; the inside of the acorn shell appears woolly.
Leaves have sharp lobe tips, with bristles at the lobe tip. Sect. Lobatae, the red oaks of North America, Central America and northern South America. Styles long; the inside of the acorn shell appears woolly. The actual nut is encased in a thin, papery skin. Leaves have sharp lobe tips, with spiny bristles at the lobe; the ring-cupped oaks of eastern and southeastern Asia. Evergreen trees growing 10–40 m tall, they are distinct from subgenus Quercus in that they have acorns with distinctive cups bearing concrescent rings of scales. IUCN, ITIS, Encyclopedia of Life and Flora of China treats Cyclobalanopsis as a distinct genus, but some taxonomists consider it a subgenus of Quercus, it contains about 150 species. Species of Cyclobalanopsis are common in the evergreen subtropical laurel forests which extend from southern Japan, southern Korea, Taiwan across southern China and northern Indochina to the eastern Himalayas, in association with trees of genus Castanopsis and the laurel family. Interspecific hybridization is quite common among oaks but between species within the same section only and most common in the white oak group.
Inter-section hybrids, except between species of sections Mesobalanus, are unknown. Recent systematic studies appear to confirm a high tendency of Quercus species to hybridize because of a combination of factors. White oaks are unable to discriminate against pollination by other species in the same section; because they are wind pollinated and they have weak internal barriers to hybridization, hybridization produces functional seeds and fertile hybrid offspring. Ecological stresses near habitat margins, can cause a breakdown of mate recognition as well as a reduction of male function in one parent species. Frequent hybridization among oaks has consequences for oak populations around the world. Frequent hybridization and high levels of introgression have caused different species in the same populations to share up to 50% of their genetic information. Having high rates of hybridization and introgression produces genetic data that does not differentiate between two morphologically distinct species, but instead differentiates populations.
Numerous hypotheses have been proposed to explain how oak species are able to remain morphologically and ecologically distinct with such high levels of gene flow, but the phenomenon is still a mystery to botanists. The Fagaceae, or beech family, to which the oaks belong, is a slow evolving clade compared to other angiosperms, the patterns of hybridization and introgression in Quercus pose a gre
Washingtonia filifera known as desert fan palm, California fan palm or California palm, is a flowering plant in the palm family native to the far southwestern United States and Baja California. Growing to 15–20 m tall by 3–6 m broad, it is an evergreen monocot with a tree-like growth habit, it has waxy, fan-shaped leaves. Other common names include California fan petticoat palm; the specific epithet filifera means "thread-bearing". W. filifera is the only palm native to the Western United States and the country's largest native palm. Primary populations are found in desert riparian habitats at spring-fed and stream-fed oases in the Colorado Desert and at a few scattered locations in the Mojave Desert, it is found near watercourses in the Sonoran Desert along the Gila River in Yuma, along the Hassayampa River and near New River in Maricopa County, in portions of Pima County, Pinal County, Mohave County, several other isolated locations in Clark County, Nevada. It is a naturalized species in the warm springs near Death Valley and in the extreme northwest of Sonora.
It is reportedly naturalized in the Southeast, Hawaii, the U. S. Virgin Islands, Australia. W. filifera grows to 18 m in height in ideal conditions. The California fan palm is known as the desert fan palm, American cotton palm, Arizona fan palm; the fronds are up to 4 m long, made up of a petiole up to 2 m long, bearing a fan of leaflets 1.5–2.0 m long. They have long, thread-like, white fibers, the petioles are pure green with yellow edges and filifera-filaments, between the segments; the trunk is gray and tan, the leaves are gray green. When the fronds die, they remain drop down to cloak the trunk in a wide skirt; the shelter that the skirt creates provides a microhabitat for invertebrates. If any red color is present on petioles or trunk, it is not a pure W. filifera, but a W. fila-busta hybrid. W. filifera lives from 80 to 250 years or more. Desert fan palms provide habitat for the giant palm-boring beetle, western yellow bat, hooded oriole, many other bird species. Hooded orioles places to build nests.
Numerous insect species visit the hanging inflorescences. The palm boring beetle Dinapate wrightii can chew through the trunks of other palms. A continued infestation of beetles can kill various genera and species of palms. W. filifera appears to be resistant to the red palm weevil via a mechanism of antibiosis — production of compounds lethal to the larvae. The desert fan palm is experiencing a population and range expansion due to global warming or removing excess mustangs. Natural oases are restricted to areas downstream from the source of hot springs, though water is not always visible at the surface. Grazing animals can kill young plants through trampling, or by eating the terminus at the apical meristem, the growing portion of the plant; this may have kept palms restricted to a lesser range than indicated by the availability of water. Today's oasis environment may have been protected from colder climatic changes over the course of its evolution. Thus, this palm is restricted by both water and climate to separated relict groves.
The trees in these groves show little if any genetic differentiation, suggesting that the genus is genetically stable. Joshua Tree National Park in the Mojave Desert preserves and protects healthy riparian palm habitat examples in the Little San Bernardino Mountains, westward where water rises through the San Andreas Fault on the east valley side. In the central Coachella Valley, the Indio Hills Palms State Reserve and nearby Coachella Valley Preserve, other large oases are protected and accessible; the Santa Rosa and San Jacinto Mountains National Monument, Anza-Borrego Desert State Park both have large and diverse W. filifera canyon oasis habitats. The fruit of the fan palm was eaten raw, cooked, or ground into flour for cakes; the Cahuilla and related tribes used the leaves to make sandals, thatch roofs, baskets. The stems were used to make cooking utensils; the Moapa band of Paiutes and other Southern Paiutes have written memories of using this palm's seed, fruit, or leaves for various purposes including starvation food.
W. filifera is cultivated as an ornamental tree. It is one of the hardiest Coryphoidiae palms, rated as hardy to USDA hardiness zone 8, it can survive brief temperatures of −10 °C with minor damage, established plants have survived, with severe leaf damage, brief periods as low as −12 °C. The plants grow best in Mediterranean climates, but can be found in humid subtropical climates such as eastern Australia and the southeastern USA, it has gained the Royal Horticultural Society's Award of Garden Merit. Johnson. "Washingtonia filifera". IUCN Red List of Threatened Species. Version 2006. International Union for Conservation of Nature. Retrieved 11 May 2006. Floridata.com: Washingtonia filifera Cornett, J. W. 2010. Desert Palm Oasis. Nature Trails Press, Palm Springs, California. Interactive Distribution Map for Washingtonia filifera USDA Plants Profile: Washingtonia filifera UC Jepson Manual treatment — Washingtonia filifera Calflora Database: Washingtonia filifera Washingtonia filifera in Flora of North America Washingtonia filifera — U.
C. CalPhotos Gallery
Cupressus arizonica, the Arizona cypress, is a North American species of trees in the cypress family. It is native to the southwestern United States, in Mexico. In the wild, the species is found in small, scattered populations, not in large forests. An example occurrence is within the Sierra Juárez and San Pedro Mártir pine-oak forests of Mexico, where it is found along with canyon live oak and California fan palm. Cupressus arizonica is a coniferous evergreen tree with a conic to ovoid-conic crown, it grows to heights of 10–25 m, its trunk diameter reaches 0.5 m. The foliage grows in varying from dull gray-green to bright glaucous blue-green; the leaves are scale-like, 2–5 mm long, produced on rounded shoots. The seed cones are globose to oblong, 15–33 mm long, with 6 or 8 scales, green at first, maturing gray or gray-brown about 20–24 months after pollination; the cones remain closed for many years, only opening after the parent tree is killed in a wildfire, thereby allowing the seeds to colonize the bare ground exposed by the fire.
The male cones are 3–5 mm long, release pollen in February–March. Up to five varieties are distinguished by some botanists, these are sometimes treated as distinct species: Cupressus arizonica var. arizonica, Arizona Cypress - secure. Southern Arizona, southwest New Mexico, south to Durango and Tamaulipas, Chisos Mountains of west Texas. Cupressus arizonica var. glabra, Smooth Arizona cypress - secure. Central Arizona. Cupressus arizonica var. montana, San Pedro Martir cypress - Vulnerable. Sierra Juárez and San Pedro Mártir pine-oak forests of Northern Baja California. Cupressus arizonica var. nevadensis, Piute cCypress - Least Concern. Southern California. Cupressus arizonica var. stephensonii, Cuyamaca cypress - Critically endangered. Southern California. Most of this population was burnt in the October 2003 Cedar Fire, though subsequent regeneration has been good. Arizona cypress the glaucous C. arizonica var. glabra, is cultivated as an ornamental tree. Unlike Monterey cypress, it has proved resistant to cypress canker, caused by the fungus Seiridium cardinale, growth is reliable where this disease is prevalent.
The cultivar'Pyramidalis' has gained the Royal Horticultural Society's Award of Garden Merit. World Wildlife Fund, ed.. "Sierra Juarez and Sierra Pedro Martir Pine-oak Forests". WildWorld Ecoregion Profile. National Geographic Society. Archived from the original on 2010-03-08. Conifer Specialist Group. "Cupressus arizonica". IUCN Red List of Threatened Species. Version 2006. International Union for Conservation of Nature. Retrieved 12 May 2006. USDA Plants Profile for Hesperocyparis arizonica Calflora as Hesperocyparis stephensonii Jepson eFlora, The Jepson Herbarium, University of California, Berkeley as Hesperocyparis stephensonii Hike Arizona.com: Photos of Arizona Cypress Cupressus arizonica in the CalPhotos Photo Database, University of California, Berkeley