Channel Islands (California)
The Channel Islands form an eight-island archipelago along the Santa Barbara Channel in the Pacific Ocean off the coast of southern California. Five of the islands are part of Channel Islands National Park, the waters surrounding these islands make up Channel Islands National Marine Sanctuary; the islands were first colonized by the Chumash and Tongva Native Americans 13,000 years ago, who were displaced by Spaniards who used the islands for fishing and agriculture. The U. S. military uses the islands as training grounds, weapons test sites, as a strategic defensive location. The Channel Islands and the surrounding waters house a diverse ecosystem with many endemic species and subspecies; the islands harbor 150 unique species of plant that are found only on the Islands and nowhere else in the world. The eight islands are split among the jurisdictions of three separate California counties: Santa Barbara County, Ventura County, Los Angeles County; the islands are divided into two groups. The four northern Islands used to be a single landmass known as Santa Rosae.
The archipelago extends for 160 miles between San Miguel Island in the north and San Clemente Island in the south. Together, the islands' land area totals about 346 square miles. Five of the islands were made into the Channel Islands National Park in 1980; the Channel Islands National Marine Sanctuary encompasses the waters six nautical miles off these islands. Santa Catalina Island is the only one of the eight islands with a significant permanent civilian settlement—the resort city of Avalon and the unincorporated town of Two Harbors. University of Southern California houses its USC Wrigley Institute for Environmental Studies marine lab in Two Harbors. Natural seepage of oil occurs at several places in the Santa Barbara Channel. Tar balls or pieces of tar in small numbers are found on the beaches. Native Americans used occurring tar, for a variety of purposes which include roofing, waterproofing and some ceremonial purposes; the Channel Islands at low elevations are frost-free and constitute one of the few such areas in the 48 contiguous US states.
It snows only on higher mountain peaks. Separated from the California mainland throughout recent geological history, the Channel Islands provide the earliest evidence for human seafaring in the Americas, it is the site of the discovery of the earliest paleontological evidence of humans in North America. The northern Channel Islands are now known to have been settled by maritime Paleo-Indian peoples at least 13,000 years ago. Archaeological sites on the island provide a unique and invaluable record of human interaction with Channel Island marine and terrestrial ecosystems from the late Pleistocene to historic times; the Anacapa Island Archeological District is a 700-acre historic district, listed on the National Register of Historic Places in 1979. The northern islands were occupied by the island Chumash, while the southern islands were occupied by the Tongva. Author Scott O'Dell wrote about the indigenous peoples living on the island in his novel Island of the Blue Dolphins. Aleut hunters visited the islands to hunt otters in the early 1800s.
The Aleuts purportedly clashed with the native Chumash. Aleut interactions with the natives were detailed in O'Dell's book; the Chumash and Tongva were removed from the islands in the early 19th century and taken to Spanish missions and pueblos on the adjacent mainland. For a century, the Channel Islands were used for ranching and fishing activities, which had significant impacts on island ecosystems, including the local extinction of sea otters, bald eagles, other species. Several of the islands were used by whalers in the 1930s to hunt for sperm whales. With most of the Channel Islands now managed by federal agencies or conservation groups, the restoration of the island ecosystems has made significant progress. An example of conservation progress has been the bald eagle, threatened due to DDT contamination, but whose populations are now recovering. With the help of scientists from the USC Wrigley Institute for Environmental Studies, the Catalina Island Fox has recovered from a low of 100 individual foxes to over 1,500 foxes in 2018.
In 1972, in "a bit of political theater”, twenty-six Brown Berets sailed to Catalina Island on tourist boats, set up a small encampment near the town of Avalon, put up a Mexican flag and claimed the island on behalf of all Chicanos, citing the Treaty of Guadalupe Hidalgo. Twenty-four days sheriff's deputies took everyone back to the mainland. Channel Islands National Park's mainland visitor center received 342,000 visitors in 2014; the islands attract around 70,000 tourists a year, most during the summer. Visitors can travel to the islands via public airplane transportation. Camping grounds are available on Anacapa, Santa Rosa, Santa Cruz, San Miguel, Santa Barbara Islands in the Channel Islands National Park. Attractions include whale watching, snorkeling and camping; the United States Navy controls San Nicolas Island and San Clemente Island, has installations elsewhere in the chain. During World War II all of southern California’s Channel Islands were put under military control, including the civilian-populated Santa Catalina where tourism was halted and established residents needed permits to travel to and from the mainland.
San Miguel Island was used as a bombing range and Santa Barbara Island as an early warning outpost under the presumed threat of a
Arbutus menziesii, the Pacific madrone or madrona, is a species of tree in the family Ericaceae, native to the western coastal areas of North America, from British Columbia to California. It is known as the madroa, madroño, madroña, or bearberry; the name "strawberry tree" may be found in relation to A. menziesii. According to the Sunset Western Garden Book, in the United States, the name "madrone" is more common south of the Siskiyou Mountains of southern Oregon and Northern California and the name "madrona" is more common north of the Siskiyous; the Concow tribe calls the tree dis-tā' - kou-wät ′ - chu. In British Columbia it is referred to as arbutus, its species name was given it in honour of the Scottish naturalist Archibald Menzies, who noted it during George Vancouver's voyage of exploration. Arbutus menziesii is an evergreen tree with rich orange-red bark that when mature peels away in thin sheets, leaving a greenish, silvery appearance that has a satin sheen and smoothness. In spring, it bears sprays of small bell-like flowers, in autumn, red berries.
The berries have hooked barbs that latch onto larger animals for migration. It is common to see madronas of about 10 to 25 metres in height, but with the right conditions trees may reach up to 30 metres. In ideal conditions madronas can reach a thickness of 5 to 8 feet at the trunk, much like an oak tree. Leaves are thick with a waxy texture, oval, 7 to 15 centimetres long and 4 to 8 centimetres broad, arranged spirally; the leaves are evergreen, lasting a few years before detaching, but in the north of its range, wet winters promote a brown to black leaf discoloration due to fungal infections. The stain lasts until the leaves detach at the end of their lifespan. Madrones are native to the western coast of North America, from British Columbia to California, they are found in Puget Sound, the Oregon Coast Range, California Coast Ranges. They are rare south of Santa Barbara County, with isolated stands south to Palomar Mountain in California. One author lists their southern range as extending as far as Baja California in Mexico, but others point out that there are no recorded specimens collected that far south, the trees are absent from modern surveys of native trees there.
However other Arbutus species are endemic to the area. The trees are difficult to transplant and a seedling should be set in its permanent spot while still small. Transplant mortality becomes significant; the site should be sunny, well drained, lime-free. In its native range, a tree needs no food once it has become established. Water and nitrogen fertilizer will boost its growth, but at the cost of making it more susceptible to disease; this plant has gained the Royal Horticultural Society's Award of Garden Merit. Native Americans ate the berries, but because the berries have a high tannin content and are thus astringent, they more chewed them or made them into a cider, they used the berries to make necklaces and other decorations, as bait for fishing. Bark and leaves were used to treat stomach aches, skin ailments, sore throats; the bark was made into a tea to be drunk for these medicinal purposes. Many mammal and bird species feed off the berries, including American robins, cedar waxwings, band-tailed pigeons, varied thrushes, mule deer, ring-tailed cats, bears.
Mule deer will eat the young shoots when the trees are regenerating after fire. It is important as a nest site for many birds, in mixed woodland it seems to be chosen for nestbuilding disproportionately to its numbers; the wood is durable and has a warm color after finishing, so it has become more popular as a flooring material in the Pacific Northwest. An attractive veneer can be made from the wood. However, because large pieces of madrona lumber warp and unpredictably during the drying process, they are not used much. Madrone is burned for firewood, since it is a hard and dense wood that burns long and hot, surpassing oak in this regard. Although drought tolerant and fast growing, Arbutus menziesii is declining throughout most of its range. One cause is fire control. Mature trees survive fire, can regenerate more after fire than the Douglas firs with which they are associated, they produce large numbers of seeds, which sprout following fire. Increasing development pressures in its native habitat have contributed to a decline in the number of mature specimens.
This tree is sensitive to alteration of the grade or drainage near the root crown. Until about 1970, this phenomenon was not recognized on the west coast; the species is affected to a small extent by sudden oak death, a disease caused by the water-mold Phytophthora ramorum. During the Soberanes Fire in the summer of 2016, the largest known specimen of madrone was burned and killed; the tree, 125 feet tall and more th
Quercus chrysolepis termed canyon live oak, canyon oak, golden cup oak or maul oak, is a North American species of evergreen oak, found in Mexico and in the western United States, notably in the California Coast Ranges. This tree is found near creeks and drainage swales growing in moist cool microhabitats, its leaves are a glossy dark green on the upper surface with prominent spines. They are sympatric with Quercus agrifolia and several other oak species. Fossil data supports a much wider distribution throughout the western United States during the early Holocene period. Native Americans used the acorns of this species after leaching of the tannins. After forest fires, canyon live oak regenerates vigorously by basal sprouting, the clonal diversity of this species has been shown to be high. Quercus chrysolepis is an evergreen tree with significant-sized spreading, horizontal branches, a broad, rounded crown; the trunk diameter can range from 30 to 100 centimeters. The elliptical to oblong leaves are 2.5 to 8.0 centimeters in length with widths of about half that dimension.
Although the leaves appear flat, they may have edge margins turned under with spiny teeth on young twigs. These leathery leaves are a glossy dark green above, with a nether surface a dull golden down becoming gray and nearly glabrous the second year. Bark of the canyon live oak is of a light gray coloration, is rather smooth or sometimes scaly. Acorns occur solitarily or in pairs. Quercus chrysolepis is found in a variety of forest communities in the southwestern United States, it is common in the mountainous regions of California with additional populations in southwestern Oregon, western Nevada, northern Baja California, southwestern New Mexico, Chihuahua. Canyon live oak is tolerant of a variety of soil types, including rocky or cobbly environments, it is hardy to cold temperatures down to −11 °F, will grow in neutral to moderately acidic soils with pH ranges of 4.5 to 7.5. An example of rocky and serpentine soil tolerance is the species occurrence at the Cedars of Sonoma County, California.
Canyon live. Quercus chrysolepis can be the dominant tree on steep canyon walls in locations of shallow rocky soils. In areas of moderate to high rainfall, it occurs on south facing slopes, in the hotter, drier parts of its distribution, on northerly slope faces. Besides the prehistoric use of canyon live oaks as a human food source, the acorns are consumed by a variety of wildlife as diverse as acorn woodpecker, California ground squirrel, dusky-footed wood rat, western harvest mouse and black-tailed deer. There seems little difference in food preference by wildlife among different oak species. Extensive hybridization of Quercus chrysolepis has been documented with several other sympatric oak species to a greater extent than for any other Quercus species; the ability of Quercus chrysolepis to compete with other dominant trees within its range has been analyzed from the standpoint of leaf architecture and photosynthetic capability. The study results explain that, in low light environments, Q. chrysolepis out-competes species with superior leaf size and crown mass per unit volume by its greater photosynthetic efficiency and leaf lifespan.
Canyon live oak gives functional habitat for many fauna by providing perching, resting, or foraging sites for numerous species of birds, shade and cover for diverse other mammals. Young Q. chrysolepis available browse. Canyon live oak woodlands serve as excellent mountain lion habitat because of the large population of deer frequenting these areas. Many species forage on canyon live oak foliage including black-tailed jackrabbit, brush rabbit, red-backed vole, Sonoma chipmunk, cactus mouse, deer mouse, porcupine. Pocket gophers feed on the cambium of young canyon live oaks. In southern California Q. chrysolepis is the food plant of Neocrania bifasciata. Canyon Live Oak is a severe allergen. Pollination: Occurs in following seasons depending on latitude and elevation: Spring. Jepson Manual treatment Record Canyon Live Oaks of Southern California's Transverse Ranges
Santa Rosa Plateau
The Santa Rosa Plateau is an upland plateau and southeastern extension of the Santa Ana Mountains in Riverside County, southern California. It is bounded by the urbanizing Inland Empire cities of Murrieta to the northeast, Temecula to the southeast; the Santa Rosa Plateau Ecological Reserve preserves 8,400 acres of the plateau, includes the Moreno and Machado Adobes, Riverside County’s oldest standing structures, other buildings from the 19th century Mexican land grant Rancho Santa Rosa. The Santa Rosa Plateau is home to several native plant communities and habitats, including purple needlegrass prairie, California oak woodland, montane chaparral, coastal sage scrub, vernal pools, which are rare in urbanized Southern California; the Engelmann oak was once widespread throughout the western U. S. Now the farthest north they are found is Pasadena; the Reserve has reproducing Engelmanns in the states. A vernal pool is a shallow depression in the soil. Fairy shrimp and other minute crustaceans hatch during lay eggs.
These eggs remain dormant during the dry months. The Santa Rosa Plateau Ecological Reserve was assembled in several stages; the intervening parcels were purchased in the 1990s by the State of California, the Riverside County Regional Park and Open Space District, the Metropolitan Water District of Southern California. Although the parcels remain under the ownership of separate agencies, they are managed cooperatively, with biological resource management, which includes prescribed fire and habitat restoration programs managed by the Nature Conservancy, visitor management; this includes operation of a visitor center and a 40-mile trail system, managed by the Riverside County Regional Park and Open-Space District. A non-profit organization, the Santa Rosa Plateau Nature Education Foundation, provides funding for field trips to the Reserve for all third graders in the area; the Reserve is home to many species of flowers. In one month, March 50 different wildflowers were reported in bloom; the best time to view the flowers is in the spring and the best trail for flowers at this time is the Vernal Pool Trail.
The one flower people come to the Reserve to see is the Chocolate Lily. It is most seen in April on the slopes of the Coronado Plateau; as the vernal pools start to evaporate, flowers grow in concentric circles around them. The most common flower around the vernal pools is the California poppy; the Reserve is known to be home to 27 species of mammal. This includes 12 species of rodents; the mammals include: badger, California myotis, gray fox, mountain lion, California mule deer, black-tailed jackrabbit, desert cottontail, brush mouse, cactus mouse, California ground squirrel, California mouse, California pocket mouse, California vole, deer mouse, desert woodrat, dusky-footed woodrat, Pacific kangaroo rat, pocket gopher, western harvest mouse, gray shrew, striped skunk, long-tailed weasel. Most mammals are nocturnal and so are seen by visitors. However, ground squirrels are diurnal and are seen. Coyotes are the second most common seen mule deer. There have been at least 185 species of bird spotted on the Reserve.
Among the larger birds, the mallard, black-shouldered kite, Cooper's hawk, red-shouldered hawk, golden eagle and American kestrel are known to nest on the site. The barn owl and great-horned owl have had their nestings confirmed. Anna's hummingbird are found year around on the Reserve while the black-chinned hummingbird is common in the spring and into the summer. If you hear a knocking on wood, it's an acorn woodpecker. Although, if it's followed by what sounds like a laugh, it may be a northern flicker. If you hear a commotion in the bushes, it may just be a rufous-sided towhee scratching through the leaf litter for insects and other invertebrates; the reserve is home to the Southwestern pond turtle. They are on the list of Species of Special Concern, they are not allowed to be taken from their habitat. The longest turtles found on the Reserve are five and a half inches; when they are wet, they are dark, making it easy for them to blend in with the mud at the bottom of ponds. They have webbed feet for efficient swimming and claws, which are used for digging nests, tearing meat, during courtship.
They feed on aquatic invertebrates. They spend most of their lives underwater, where they mate, they leave the water on a daily basis to bask. In southern California, pond turtle populations have declined 95-99%; the Reserve is one of only four to six reproductively viable populations of the Southwestern pond turtle in southern California. Snakes found on the Ecological Reserve include: San Bernardino ring-necked snake, Hammond's two-striped garter snake, coastal rosy boa, Western yellow-bellied racer, California striped racer, San Joaquin coachwhip, red diamond rattlesnake, Southern Pacific rattlesnake, San Diego gopher snake, California kingsnake. Other reptiles include: San Diego horned lizard, western fence lizard, granite spiny lizard, side-blotched lizard, western skink, western whiptail, San Diego alligator lizard. Amphibians found on the Ecological Reserve include: coast range newt, garden slender salamander, black-bellied salamander, western spadefoot toad, Pacific treefrog, California red-legged frog, bullfrog.
Bullfrogs are an invasive species, which because of their superior size, ta
Human overpopulation occurs when the ecological footprint of a human population in a specific geographical location exceeds the carrying capacity of the place occupied by that group. Overpopulation can further be viewed, in a long term perspective, as existing if a population cannot be maintained given the rapid depletion of non-renewable resources or given the degradation of the capacity of the environment to give support to the population. Changes in lifestyle could reverse overpopulated status without a large population reduction; the term human overpopulation refers to the relationship between the entire human population and its environment: the Earth, or to smaller geographical areas such as countries. Overpopulation can result from an increase in births, a decline in mortality rates, an increase in immigration, or an unsustainable biome and depletion of resources, it is possible for sparsely populated areas to be overpopulated if the area has a meagre or non-existent capability to sustain life.
Advocates of population moderation cite issues like quality of life, carrying capacity, risk of starvation as a basis to argue for population decline. Scientists suggest that the human impact on the environment as a result of overpopulation, profligate consumption and proliferation of technology has pushed the planet into a new geological epoch known as the Anthropocene. Human population has been rising continuously since the end of the Black Death, around the year 1350, although the most significant increase has been since the 1950s due to medical advancements and increases in agricultural productivity; the rate of population growth has been declining since the 1980s, while the absolute total numbers are increasing. Recent rate increases in several countries enjoying steady declines are apparently contributing to continued growth in total numbers; as pointed out by Hans Rosling, the critical factor is that the population is not "just growing", but that the growth ratio reached its peak and the total population is now growing much slower.
The UN population forecast of 2017 was predicting "near end of high fertility" globally and anticipating that by 2030 over ⅔ of world population will be living in countries with fertility below the replacement level. And for total world population to stabilize between 10-12 billion people by year 2100; the United Nations has expressed concerns on continued population growth in sub-Saharan Africa. Recent research has demonstrated; as of April 14, 2019 the world's human population is estimated to be 7.699 billion. Or, 7,622,106,064 on May 14, 2018 and the United States Census Bureau calculates 7,472,985,269 for that same date, and over 7 billion by the United Nations. Most contemporary estimates for the carrying capacity of the Earth under existing conditions are between 4 billion and 16 billion. Depending on which estimate is used, human overpopulation may or may not have occurred; the rapid recent increase in human population is causing some concern. The population is expected to reach between 8 and 10.5 billion between the years 2040 and 2050.
In 2017, the United Nations increased the medium variant projections to 9.8 billion for 2050 and 11.2 billion for 2100. The recent rapid increase in human population over the past three centuries has raised concerns that the planet may not be able to sustain present or future numbers of inhabitants; the InterAcademy Panel Statement on Population Growth, circa 1994, stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, pollution, are aggravated by the population expansion. Other problems associated with overpopulation include the increased demand for resources such as fresh water and food and malnutrition, consumption of natural resources faster than the rate of regeneration, a deterioration in living conditions. Wealthy but populated territories like Britain rely on food imports from overseas; this was felt during the World Wars when, despite food efficiency initiatives like "dig for victory" and food rationing, Britain needed to fight to secure import routes.
However, many believe that waste and over-consumption by wealthy nations, is putting more strain on the environment than overpopulation. In spite of concerns about overpopulation, widespread in developed countries, the number of people living in extreme poverty globally shows a stable decline though the population has grown seven-fold over the last 200 years. Child mortality has declined, which in turn has led to reduced birth rates, thus slowing overall population growth; the global number of famine-related deaths have declined, food supply per person has increased with population growth. Most countries have no direct policy of limiting their birth rates, but the rates have still fallen due to education about family planning and increasing access to birth control and contraception. Concern about overpopulation is an ancient topic. Tertullian was a resident of the city of Carthage in the second century CE, when the population of the world was about 190 million, he notably said: "What most meets our view is our teeming population.
Our numbers are burdensome to the world, which can hardly support us.... In deed and famine, wars, earthquakes have to be regarded as a remedy for nations, as the means of pruning the luxuriance of the human race." Before that, Plato and others broached the topic as well. Throughout recorded history, population growth has been slow despite high birth rates, due to war and other diseases, high infant mortalit
Cercis occidentalis, the western redbud or California redbud, is a small tree or shrub in the legume family. It is found from California to Utah and Arizona, it is recognized when it is in bloom from March to May, when it is covered with small pink to purple flowers. Cercis occidentalis has thin, shiny brown branches that bear shiny heart-shaped leaves which are light green early in the season and darken as they age. Leaves on plants at higher elevation may turn red as the weather cools; the showy flowers are bright pink or magenta, grow in clusters all over the shrub, making the plant colorful and noticeable in the landscape. The shrub bears 3-inch-long brown legume pods which are thin and dry. Indigenous Californians use the twigs of the western redbud to weave baskets, prune the shrub to encourage growth of new twigs; the bark provides a faint reddish dye for the finished basketry. The Concow tribe calls the tree dop or tal'k. Cercis occidentalis is cultivated as an ornamental plant and tree, for planting in parks and gardens, as a street tree.
It is used in drought tolerant, native plant, wildlife gardens. Casebeer, M.. Discover California Shrubs. Sonora, California: Hooker Press. ISBN 0-9665463-1-8 Jepson Manual Treatment — Cercis occidentalis CalFlora Database: Cercis occidentalis USDA Plants Profile: Cercis orbiculata Interactive Distribution Map for Cercis occidentalis
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