Typical tropical savanna in Northern Australia demonstrating the high tree density and regular spacing characteristic of many savannas.

A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses.^[1][2][3] Some classification systems^[which?] also recognize a grassland savanna from which trees are absent.^[4] This article deals only with savanna under the common definition of a grassy woodland with a significant woody plant component.

It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forest. Savannas are also characterized by seasonal water availability, with the majority of rainfall confined to one season. Savannas are associated with several types of biomes. Savannas are frequently in a transitional zone between forest and desert or prairie. Savanna covers approximately 20% of the Earth's land area. The largest area of savanna is in America.

Etymology[link]

San Rafael Gran Sabana, Venezuela.

Although the term savanna is believed to have originally come from an Arawak word describing "land which is without trees but with much grass either tall or short" (Oviedo y Valdes, 1535), by the late 1800s it was used to mean "land with both grass and trees". It now refers to land with grass and either scattered trees or an open canopy of trees.

Spanish explorers familiar with the term "sabana" called the grasslands they found around the Orinoco River "llanos", as well as calling Venezuelan and Colombian grasslands by that specific term. "Cerrado" was used on the higher savannas of the Brazilian Central Plateau.^[5]

Distribution[link]

Many grassy landscapes and mixed communities of trees, shrubs, and grasses were described as savanna before the middle of the 19th century, when the concept of a tropical savanna climate became established. The Köppen climate classification system was strongly influenced by effects of temperature and precipitation upon tree growth, and his over-simplified assumptions resulted in a tropical savanna classification concept which resulted in it being considered as a "climatic climax" formation. The common usage meaning to describe vegetation now conflicts with a simplified yet widespread climatic concept meaning. The divergence has sometimes caused areas such as extensive savannas north and south of the Congo and Amazon Rivers to be excluded from mapped savanna categories.^[5]

"Barrens" has been used almost interchangeably with savanna in different parts of North America. Sometimes midwestern savanna were described as "grassland with trees". Different authors have defined the lower limits of savanna tree coverage as 5-10% and upper limits range from 25-80% of an area.^[6]

Two factors common to all savanna environments are rainfall variations from year to year, and dry season wildfires. In the Americas, e.g. in Belize, Central America, savanna vegetation is similar from Mexico to South America and to the Caribbean.^[7]

Threats[link]

Changes in fire management[link]

Savannas are subject to regular wildfires and the ecosystem appears to be the result of human use of fire. For example, Native Americans created the Pre-Columbian savannas of North America by periodically burning where fire-resistant plants were the dominant species.^[8] Pine barrens in scattered locations from New Jersey to coastal New England are remnants of these savannas. Aboriginal burning appears to have been responsible for the widespread occurrence of savanna in tropical Australia and New Guinea,^[9] and savannas in India are a result of human fire use.^[10] The maquis shrub savannas of the Mediterranean region were likewise created and maintained by anthropogenic fire.^[11]

Prescribed burn; Wisconsin bur oak savanna

These fires are usually confined to the herbaceous layer and do little long term damage to mature trees. However, these fires either kill or suppress tree seedlings, thus preventing the establishment of a continuous tree canopy which would prevent further grass growth. Prior to European settlement aboriginal land use practices, including fire, influenced vegetation^[12] and may have maintained and modified savanna flora.^[3][9] It has been suggested by many authors^[12][13] that aboriginal burning created a structurally more open savanna landscape. Aboriginal burning certainly created a habitat mosaic that probably increased biodiversity and changed the structure of woodlands and geographic range of numerous woodland species.^[9][12] It has been suggested by many authors^[13][14] that with the removal or alteration of traditional burning regimes many savannas are being replaced by forest and shrub thickets with little herbaceous layer.

The consumption of herbage by introduced grazers in savanna woodlands has led to a reduction in the amount of fuel available for burning and resulted in fewer and cooler fires.^[15] The introduction of exotic pasture legumes has also led to a reduction in the need to burn to produce a flush of green growth because legumes retain high nutrient levels throughout the year, and because fires can have a negative impact on legume populations which causes a reluctance to burn.^[16]

Grazing and browsing animals[link]

Oak savanna, United States

The closed forests types such as broadleaf forests and rainforests are usually not grazed owing to the closed structure precluding grass growth, and hence offering little opportunity for grazing.^[17] In contrast the open structure of savannas allows the growth of a herbaceous layer and are commonly used for grazing domestic livestock.^[18] As a result much of the world's savannas have undergone change as a result of grazing by sheep, goats and cattle, ranging from changes in pasture composition to woody weed encroachment.^[19]

The removal of grass by grazing affects the woody plant component of woodland systems in two major ways. Grasses compete with woody plants for water in the topsoil and removal by grazing reduces this competitive effect, potentially boosting tree growth.^[20] In addition to this effect, the removal of fuel reduces both the intensity and the frequency of fires which may control woody plant species.^[21] Grazing animals can have a more direct effect on woody plants by the browsing of palatable woody species. There is evidence that unpalatable woody plants have increased under grazing in savannas.^[22] Grazing also promotes the spread of weeds in savannas by the removal or reduction of the plants which would normally compete with potential weeds and hinder establishment.^[12] In addition to this, cattle and horses are implicated in the spread of the seeds of weed species such as Prickly Acacia (Acacia nilotica) and Stylo (Stylosanthes spp.).^[15] Alterations in savanna species composition brought about by grazing can alter ecosystem function, and are exacerbated by overgrazing and poor land management practices.

Introduced grazing animals can also affect soil condition through physical compaction and break-up of the soil caused by the hooves of animals and through the erosion effects caused by the removal of protective plant cover. Such effects are most likely to occur on land subjected to repeated and heavy grazing.^[23] The effects of overstocking are often worst on soils of low fertility and in low rainfall areas below 500 mm, as most soil nutrients in these areas tend to be concentrated in the surface so any movement of soils can lead to severe degradation. Alteration in soil structure and nutrient levels affects the establishment, growth and survival of plant species and in turn can lead to a change in woodland structure and composition.

Tree clearing[link]

Large areas of savanna have been cleared of trees, and this clearing is continuing today. For example until recently 480,000 ha of savanna were cleared annually in Australia alone primarily to improve pasture production.^[12] Substantial savanna areas have been cleared of woody vegetation and much of the area that remains today is vegetation that has been disturbed by either clearing or thinning at some point in the past.

Clearing is carried out by the grazing industry in an attempt to increase the quality and quantity of feed available for stock and to improve the management of livestock. The removal of trees from savanna land removes the competition for water from the grasses present, and can lead to a two to fourfold increase in pasture production, as well as improving the quality of the feed available.^[24] Since stock carrying capacity is strongly correlated with herbage yield there can be major financial benefits from the removal of trees.^[25] The removal of trees also assists grazing management. For example in sheep grazing regions of dense tree and shrub cover harbours predators, leading to increased stock losses^[26] while woody plant cover hinders mustering in both sheep and cattle areas.^[27]

A number of techniques have been employed to clear or kill woody plants in savannas. Early pastoralists used felling and girdling, the removal of a ring of bark and sapwood, as a means of clearing land.^[28] In the 1950s arboricides suitable for stem injection were developed. War-surplus heavy machinery was made available, and these were used for either pushing timber, or for pulling using a chain and ball strung between two machines. These two new methods of timber control, along with the introduction and widespread adoption of several new pasture grasses and legumes promoted a resurgence in tree clearing. The 1980s also saw the release of soil-applied arboricides, notably tebuthiuron, that could be utilized without cutting and injecting each individual tree.

In many ways "artificial" clearing, particularly pulling, mimics the effects of fire and, in savannas adapted to regeneration after fire as most Queensland savannas are, there is a similar response to that after fire.^[29] Tree clearing in many savanna communities, although causing a dramatic reduction in basal area and canopy cover, often leaves a high percentage of woody plants alive either as seedlings too small to be affected or as plants capable of re-sprouting from lignotubers and broken stumps. A population of woody plants equal to half or more of the original number often remains following pulling of eucalypt communities, even if all the trees over 5 metres are uprooted completely.

Exotic plant species[link]

Equatorial savanna in the East Province of Cameroon

A number of exotic plants species have been introduced to the savannas around the world. Amongst the woody plant species are serious environmental weeds such as Prickly Acacia (Acacia nilotica), Rubbervine (Cryptostegia grandiflora), Mesquite (Prosopis spp.), Lantana (Lantana camara and L. montevidensis) and Prickly Pear (Opuntia spp.) A range of herbaceous species have also been introduced to these woodlands, either deliberately or accidentally including Rhodes grass and other Chloris species, Buffel grass (Cenchrus ciliaris), Giant rat's tail grass (Sporobolus pyramidalis) parthenium (Parthenium hysteropherus) and stylos (Stylosanthes spp.) and other legumes. These introductions have the potential to significantly alter the structure and composition of savannas worldwide, and have already done so in many areas through a number of processes including altering the fire regime, increasing grazing pressure, competing with native vegetation and occupying previously vacant ecological niches.^[29][30] Other plant species include: white sage, spotted cactus, cotton seed, rosemary.

Climate change[link]

There exists the possibility that human induced climate change in the form of the greenhouse effect may result in an alteration of the structure and function of savannas. Some authors^[31] have suggested that savannas and grasslands may become even more susceptible to woody plant encroachment as a result of greenhouse induced climate change. However, a recent case described a savanna increasing its range at the expense of forest in response to climate variation, and potential exists for similar rapid, dramatic shifts in vegetation distribution as a result of global climate change, particularly at ecotones such as savannas so often represent.^[32]

Savanna ecoregions[link]

Mediterranean savanna in Alentejo region, Portugal.

Savanna ecoregions are of several different types:

• Tropical and subtropical savannas are classified with tropical and subtropical grasslands and shrublands as the tropical and subtropical grasslands, savannas, and shrublands biome. The savannas of Africa, including the Serengeti, famous for its wildlife, are typical of this type.
• Temperate savannas are mid-latitude savannas with wetter summers and drier winters. They are classified with temperate savannas and shrublands as the temperate grasslands, savannas, and shrublands biome, that for example cover much of the Great Plains of the United States. (See areas such as the Central forest-grasslands transition).
• Mediterranean savannas are mid-latitude savannas in Mediterranean climate regions, with mild, rainy winters and hot, dry summers, part of the Mediterranean forests, woodlands, and scrub biome. The oak tree savannas of California, part of the California chaparral and woodlands ecoregion, fall into this category.
• Flooded savannas are savannas that are flooded seasonally or year-round. They are classified with flooded savannas as the flooded grasslands and savannas biome, which occurs mostly in the tropics and subtropics.
• Montane savannas are high-altitude savannas, located in a few spots around the world's high mountain regions, part of the montane grasslands and shrublands biome. The lowland savannas of the Angolan Scarp savanna and woodlands ecoregion are an example.

See also[link]

References[link]

External links[link]

Media related to Savanna at Wikimedia Commons

• The Savanna

Savanna Samson
Savanna Samson attending the AVN Awards Show at the Palms Casino Resort, Las Vegas, Nevada on January 9, 2010
Born	(1967-10-14) October 14, 1967 (age 44)[1][2]
Other names	Savanah Samson, Savanna
Height	5 ft 5 in (1.65 m)[3]
No. of adult films	83 (per IAFD)
Website
http://www.clubsavannasamson.com/

Savanna Samson, is an American pornographic actress.^[4] The winner of several AVN Awards, she has spent most of her career as a contract performer with major producer Vivid Entertainment, and is known for her roles in acclaimed adult films such as The New Devil in Miss Jones. In addition to performing, she has her own adult film studio, Savanna Samson Productions. A native of upstate New York, she entered the adult film industry in 2000, after working as a dancer at the Manhattan strip club, Scores.

Samson has gained mainstream recognition with appearances on television shows such as Saturday Night Live, The Daily Show and 30 Rock. Her wide range of activities outside pornography include working as a sex-advice columnist, a radio presenter and a political correspondent. She also produces her own line of wines, has a recording contract with E1 Music and is a trained ballerina.

Early life[link]

One of five daughters, Samson grew up Roman Catholic in Watertown, New York.^[4][5] She began dancing at a young age,^[5] and at 17 moved to New York City to pursue a career in ballet. However, she eventually gave this up, admitting she "wasn't good enough", and took a job dancing at the Manhattan strip club Scores,^[4] on the recommendation of her sister who worked there.^[5] When starting at the club, she chose the stage name Savanna in homage to a character in The Prince of Tides. The surname Samson, taken from the biblical figure, was added later in her career to distinguish her from porn actress Savannah.^[6] While at Scores, she met her future husband, wine merchant Daniel Oliveros, with whom she now has a son.^[5]

Adult film career[link]

Samson's move into the adult film business began in 2000, after she wrote a letter to Italian porn actor and director Rocco Siffredi, asking to work with him. She initially wanted to make a movie in order to fulfill a fantasy, after her husband had given her the idea, and hoped no one she knew would find out. However, after her first movie, Rocco Meats An American Angel In Paris, which was nominated for "Best Foreign Release" at the AVN Awards, she got what she described as "porn fever" and went on to make further movies.^[4][5][7] Her family soon discovered her film career when she appeared on The Howard Stern Show and Entertainment Tonight. Samson stated in 2006, "My parents are devastated by my career choices".^[4][5]

In April 2002, she signed an exclusive contract with Vivid Entertainment. She continued to live in New York, and commuted to California to shoot films for the company.^[8] Samson was among three Vivid Girls to be profiled in an early-2003 issue of Vanity Fair, as part of an annual roundup of the entertainment industry. The Girls were featured alongside other entertainers, such as Daniel Day-Lewis and Julianne Moore, in a double-page photograph taken at Elton John's home on the French Riviera.^[9] She was also one of several Vivid Girls to provide content for the book How to Have a XXX Sex Life: The Ultimate Vivid Guide, published by ReganBooks on July 20, 2004.^[10][11] Samson helped promote the book with appearances on The O'Reilly Factor and The Howard Stern Show.^[12][13] In May 2004, she joined several other porn actresses as a columnist for AVNInsider.com.^[14] At the 2004 AVN Awards, Samson won "Best Actress – Film" and "Best Group Sex Scene – Film" for her role in Looking In, a 2003 film about four suburban couples who have a view into each other's houses.^[15][16]

Along with comedian Thea Vidale, Samson hosted the 2005 AVN Awards,^[17] at which she won awards herself for "Best All-Girl Sex Scene – Film" and "Best Group Sex Scene – Film".^[18] In February 2005, Samson began co-hosting a daily music-and-talk radio show on the Internet station Electric Eye Radio.^[19] Later in the year, she featured alongside Jenna Jameson in Vivid's high-budget remake of the classic adult film The Devil in Miss Jones.^[20] Samson's role as Miss Jones earned her the 2006 AVN Awards for "Best Actress – Film" and "Best All-Girl Sex Scene – Film".^[21] During her acceptance speech, she revealed the importance of support from her peers and said "most of my family is pretty ashamed of what I do".^[22][23]

Samson announced in early 2006 that she had started her own production company, Savanna Samson Productions, which would release one film a year, distributed exclusively by Vivid.^[24] During 2006, Samson appeared on The Tyra Banks Show, The Dr. Keith Ablow Show, Secret Lives of Women, and for the second time, Saturday Night Live.^{[25][26][27][28]} Michael Lucas' 2006 gay-porn remake of La Dolce Vita featured a cameo appearance by Samson,^[29][30] which in 2007 won her the GayVN Award for "Best Non-Sexual Performance".^[31]

Early in 2007, Samson signed a record contract with Koch Records, now known as E1 Music, who approached her after hearing her sing during a radio tour.^[32] On May 3, 2007, she appeared as a guest on the WNYC radio series, The Tristan Mysteries, to discuss Richard Wagner's opera "Tristan und Isolde". A long-time Wagner fan, Samson stated "I think I'm in a unique position to discuss the sensual aspects of the 'Tristan and Isolde' characters and of opera in general".^[33][34][35] In June 2007, Savanna Samson Productions released its first title, Any Way You Want Me, an interactive movie directed by and starring Samson.^[36][37] She also appeared in the 2007 film Debbie Does Dallas ... Again, a sequel to the 1978 classic Debbie Does Dallas, as well as its "making of" series that was broadcast weekly on Showtime.^[38] The film gained her a 2008 AVN Award for "Best Group Sex Scene – Film".^[39]

In April 2008, Samson became a political correspondent on Fox News Channel's late-night talk show Red Eye w/ Greg Gutfeld.^[40] She had made several previous appearances on the show, and in 2007 had endorsed New York mayor Rudy Giuliani's Republican presidential candidacy.^[41][42] September 2008 saw the unveiling of her debut album, Possession,^[43] and her first single, a title track co-written by Samson during the breakup of her marriage. Commenting on the theme of the song, she said, "People see me nude and having sex and think they know me and that I'm available, but I'm no more available than Angelina Jolie".^[44] Later in the month, she had a cameo role on The Daily Show, in which she portrayed CBS Evening News anchor Katie Couric in a commercial for a fictional action-adventure show. In the appearance, Samson asks Daily Show correspondent Jason Jones, "Hey, Jones, you really think you've got the balls for that story?"^[45][46] She began writing a sex-advice column for the adult entertainment site XCritic.com in June 2009, having previously written such columns for Men’s Fitness magazine and AdultFriendFinder.com.^[47][48] Samson made her mainstream acting debut in the 30 Rock episode, "Into the Crevasse", which first aired on October 22, 2009. In the episode, she plays a porn version of Tina Fey's character, Liz Lemon.^[49][50] In 2011, Samson will be inducted into the AVN Hall of Fame. ^[51]

According to the Internet Adult Film Database, as of May 2010 Samson had appeared in 90 adult movies, including compilations containing recycled scenes.^[3] A 2006 article in The New York Times reported that she earns from $20,000 to over $100,000 per film, depending on sales, with each one taking from three days to two weeks to make.^[4] An Adult Video News article written in February 2006 stated that Samson had five years left on her contract with Vivid.^[24]

Winemaking[link]

Samson at the 2008 Adult Entertainment Expo

Despite enjoying her career in the adult film industry, Samson felt it left her unfulfilled. In 2005, while on vacation in Tuscany, Italy, she decided she could "leave a mark on this world" by making wine.^[4] The wife of a wine merchant,^[52] she had frequently traveled to Italy and France, and often fantasized about owning her own vineyard. When she was a child, she had helped her family make wine in their basement.^[7]

She formed the company, Savanna Samson Wines, and asked Italian winemaker and consultant Roberto Cipresso to help find a blend of grapes local to Tuscany that would produce her ideal flavor. They eventually chose a mixture of 70 percent Cesanese, 20 percent Sangiovese and 10 percent Montepulciano, which produced a red wine that she named Sogno Uno, meaning Dream One. Its label played on Samson's notoriety as a porn star, featuring a side view of her wearing only a see-through gown and high heels.^[4][5][53] Wine critic Robert M. Parker, Jr. gave Sogno Uno a rating of 90 to 91 out of 100, and described it as "awfully good".^[4] A gala launch was held for the wine at a Manhattan restaurant on February 27, 2006.^[54] On the following Saturday Night Live, a news parody segment poked fun at Samson’s new venture, commenting that the wine "goes well with meat... and fish".^[55] By June 2007, her company had produced a further two wines.^[56]

Awards[link]

• 2004 AVN Award for Best Actress for Looking In^[15]
• 2004 AVN Award for Best Group Sex Scene – Film for Looking In^[15]
• 2005 AVN Award for Best All-Girl Sex Scene – Film for The Masseuse (with Jenna Jameson)^[18]
• 2005 AVN Award for Best Group Sex Scene – Film for Dual Identity^[15]
• 2005 Eroticline Award for Best Erotic Actress in the World^[57]
• 2006 XRCO Award for Best Single Performance – Actress for The New Devil in Miss Jones^[58]
• 2006 AVN Award for Best Actress – Film for The New Devil in Miss Jones^[21]
• 2006 AVN Award for Best All-Girl Sex Scene – Film for The New Devil in Miss Jones^[21]
• 2007 GayVN Award for Best Non-Sexual Performance for Michael Lucas' La Dolce Vita
• 2008 AVN Award for Best Group Sex Scene – Film for Debbie Does Dallas ... Again^[39]
• 2011 AVN Hall of Fame^[59]

See also[link]

• List of celebrities who own wineries and vineyards

References[link]

External links[link]

Wikimedia Commons has media related to: Savanna Samson

• Official website
• Savanna Samson at the Internet Movie Database
• Savanna Samson at the Internet Adult Film Database
• Savanna Samson at the Adult Film Database
• Savanna Samson exclusive interview on Adversus
• Adult DVD Talk interview (audio)