World Veg Systems

8/8/2019 World Veg Systems

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World Natural Vegetation

Systems

World Vegetation SystemsIntroduction

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Deciduous Forests, Texas HillCountry

• Vegetation is found nearly everywhere.

Deciduous Forest, Texas Hill Country

Vegetation is found nearly everywhere.

htt ://en.wiki edia.or /wiki/Ima e:S rin F

ary Lee Nolan, PhDified and edited b RK Vermillion



Plants cling to the cold slopes ofmountains.

• Glacier National Park, Montana

http://www.alberta-travel.com/files/Glacier-Park-Avalanche.html



..and struggle to survive in dryconditions of deserts.

• Death Valley NP, California



Where warm air is constant andmoisture abundant,

• As in rainy tropical lands, the land surface

is covered with a dense blanket ofvegetation.

Where warmth is constant and moisture abundant, as in rainy tropical lands,The land surface is covered with a dense blanket of vegetation. (Monteverde,Costa Rica)



Chlorophyll, which gives plants theircharacteristic green tones, allows plants tocombine water, carbon dioxide and solarenergy into biomass through a process called

photosynthesis .



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As photosynthesis occurs, carbon dioxide and water are converted intoorganic compounds and oxygen.



Plants not only provide the basic source of nourishment for all forms of life, but

also perpetuate the earth’s oxygen rich atmosphere.

http://cronkitenews.jmc.asu.edu/?p=176



Natural vegetation consists of the plants that develop in an area due to natura

conditions of soil and climate (Mt. Rainier NP, Washington)

http://travel.webshots.com/photo/2067542510050301256AGtBRD



Although much of the earth’s vegetation at present is either planted or cultivatedor has been greatly modified by human and domesticated animals, it is possible

to generalize about the natural vegetation of a particular place due toclimate and soil (Mendocino, CA)



Plants are typically found with other types of plants

that are adapted to the same kind of environment.These associated plant species, which form the vegetation

of a particular place, make up a plant community.(Desert Botanical Gardens of Phoenix, AZ)

http://travel.webshots.com/photo/221644462



Each plant community is part of an

ecosystem that consists of all the

plants and animals in a place as they

interact with each other and with elementsof the inorganic environment..

https://reader009.{domain}/reader009/html5/0527/5b0a6676534af/5b0a6684bd2bc.jpg



Biomes

The word biome is used by ecologists and biogeographersto refer to highly generalized ecosystem types that can be

described and mapped on a world scale.



Although a biome includes animals along with attributes of the inorganicenvironment such as soil minerals and water, it is usually named after itsdominant vegetation association. These zebras, for example, live

in a tropical savanna biome .



The reason for the emphasis onvegetation is that plants normallymake up the bulk of the biomass,or total weight of the organisms,and are often more conspicuousparts of the visible landscape than

are animals (Tobago).

htt ://www.freewebs.com/vlie tickets-ko en/costarica.htm



http://www.cas.vanderbilt.edu/bioimages/ecoregions/50512.htm

Because biomes are described in terms of plant life,

it is useful to review the major taxonomic categories

of plants.



http://en.wikipedia.org/wiki/Image:RedMoss.jpg

Small low growing plants, such as mosses and liverworts,

are referred to as bryophytes .



http://en.wikipedia.org/wiki/Image:Sa-fern.jpg

Pteridophytes include ferns, horsetails, and club mosses, all of

which are spore bearing plants that thrive in humid environments.



In tropical rainforests, pteridophytes such

as these tree ferns reach heights of 50 feet or more.

Millions of years ago, these plants were far moreprevalent than today.



Gymnosperms , the term meaning “naked seeds”, carry their

seeds in cones. When the cones open, the seeds fall out. As

a group, gymnosperms were also more common in thegeologic past. http://en.wikipedia.org/wiki/Conifer_cone



The most important of these coniferous plants at present are needle-leafevergreen trees such as pines and this Korean fir. The wood of thesetrees a simple cellular and they are often referred to as “softwoods”.

Some conifers, such as the Douglas fir, are considered “hardwoods”.http://en.wikipedia.org/wiki/Image:Abies_koreana_%28szyszki%29.JPG



Angiosperms are flowering plants that develop seeds protected

by a fruit, nut or pod. This is a sweetbay magnolia, common to the

S.E. U.S. http://en.wikipedia.org/wiki/Angiosperms



These plants (angiosperms) include many species of trees, shrubs,grasses, and forbs.Angiosperms have been the dominant vegetation on much of the earth’s

surface for the past 50 to 60 million years.http://en.wikipedia.org/wiki/Image:Morton_Arboretum_woodland.jpg



An important structural distinction between types of plants is made on thebasis of the stem or trunk. Woody plants , such as trees and shrubs, havetrunks composed of a hard fibrous material.

http://en.wikipedia.org/wiki/Image:TJ_harvesteri.jpg



A tree is a woody plant with a

single main trunk that branchesInto a crown toward the top.This is a coastal redwood,

http://en.wikipedia.org/wiki/Image:Coastredwood.jpg



Woody vines that climb trees

Are called lianas.These plants are particularlyCommon in tropical forests.http://en.wikipedia.org/wiki/Lianas



Small, tender plants without woody stems are collectively known as

herbs . Herbaceous vegetation is subdivided into grasses and forbs .



Grasses are characterized by narrow leaves and stems growing from roots.http://upload.wikimedia.org/wikipedia/en/7/78/Grass-plant-structure.png



Forbs are broadleafed herbs that put forth leaves from shoots and generallygrow from the tips rather than their roots.http://en.wikipedia.org/wiki/Image:Cirsium_arvense_with_Bees_Richard_Bartz.jpg



Epiphytes are plants that grow on other plants and are, therefore,

out of contact with the soil. This Costa Rican tree harbors a variety

Of bromeliads.http://en.wikipedia.org/wiki/Image:DirkvdM_epiphytes.jpg



In humid tropical regions, most plants are evergreen . They loose oldLeaves and grow new ones through out the year (Amazon River)http://en.wikipedia.org/wiki/Image:River_in_the_Amazon_rainforest.jpg.



http://en.wikipedia.org/wiki/Image:Alpine_flora_logan_pass.jpg

Plants growing in harsher climates respond to seasonal changes in various

ways. Annuals are plants that go to seed and die before the onset of dry or cold

seasons.



Perennials survive the periods of unfavorable for plant growth in various

Ways. Deciduous trees and shrubs shed their leaves and become

dormant during seasons of cold or too dry to favor growth

(Longleafpine/oak Georgia USA). http://www.cooperativeconservationamerica.org/viewproject.asp?pid=552



The majority of broadleafed woody plants in temperate zones are deciduous.

Euonymous alata ‘Compacta,’ or winged burning bush. It will soon looseits leaves.



The foliage of coniferous needle-leafed plants is tough and thin and most of these

Trees are evergreens even in climates with cold winters as here on the south sideOf Mount Hood Oregon.http://www.seeyououtside.com/mthoodpix/south/mthoodsouthP1290079.jpg



A few species of needle-leafed trees are deciduous. The needles of these

western larches in Oregon have turned golden prior to being shed in thelate fall. The trees in the foreground are evergreen pines.http://www.photoseek.com/01CAN-11-16-GlacierLarch.jpg



Leaf texture vary greatly depending on climate, habitat, and the different degreeswith which water loss from the leaf into the air constitutes a problem for plant growth.

Leaves of average thickness are described as membranous .Sugar maple in the fall. http://landscaping.about.com/od/fallfoliagetrees/ig/Fall-Foliage-Pictures.--1G/Maple-Leaves-Close-Up.htm



Sclerophyllous leaves are hard, leathery and thick, thus reducing moisture loss.

Young Manzanitas leaf, San Francisco, CA http://www.nativespaces.org/2006/08/manzanitas_of_brotherhood.html



Succulent leaves and stems can hold large amounts of water in their spongy

tissues and are characteristic of plants growing in arid conditions. Agave, AZ



These varied types of leaves are all adaptations to particular types ofenvironments. The amount of moisture available for plant growth is

especially important. Fall in New England.http://www.atpm.com/13.04/new-england/



The higher the temperature, the greater the amount of moisture needed tosustain a given type of community. Thus in the very hot region of the SW of the US,desert conditions may be found in areas with close to 10 inches of annual rainfall.Joshua Tree, Nevada. http://www.dustydavis.com/blogimages/joshua_tree_large.jpg



Under subarctic conditions, the sameamount of precipitation may support

forest vegetation. Evapotranspiration Is low. Boreal Forest, Canada.http://staffwww.fullcoll.edu/tmorris/elements_of_ecology/chapter_6.htm

http://www.ffdp.ca/hww2.asp?id=354



Hydrophytes are plants that can grow in water or in boggy habitats where hight t bl t i t th th f l t Pit h Pl t B E t T



water tables restrict the growth of many plants. Pitcher Plant Bog, East Texashttp://www.fs.fed.us/wildflowers/regions/southern/BoykinSprings/images/pitcher_plant_bog_lg.jpg



Mesophytes , such as these ponderosa pines, are plants found in place

with intermediate amounts of water available on a fairly regular basis.http://www-mtl.mit.edu/~fana/Alaska_trip/Seattle_louise/kamloops_ponderosa_camp_medium.jpg



This African baobab treerepresents plants that are

adapted to areas with ayearly cycle of droughtfollowing adequate moisture.These are called

t ropophytes after

The Greek word tropo



In wet-dry tropical regions tropophytes may lose their leaves as the dry season

advances and bear foliage again during times of rain. Here in Botswana,

in southern Africa, trees tapping water from the Chobe River are green during

the dry season in contrast with the low forest on higher ground.http://farm2.static.flickr.com/1185/1436293519_97deaba9f3.jpg



Temperature directly affects the rates at which physiological processes take place.Many tropical plants can not withstand cold temperatures and thus are restricted

to regions with mild temperatures year-round such as here in Roatan, Honduras.http://www.tulum.com/list_hotel_graphic.cfm?1=1&STARTROW=141&txtCountry=&intCategory=&txtHotelName=



htt :// en.wiki edia.or /wiki/Ima e:Icebreaker in reenland 2.JPG

Other plants adapted to colder climates,fail to flourish in tropical regions. In

general, however, the cooler the averageannual temperature, the smaller thenumber of plant species capable ofsurviving as here in Greenland.



Biogeograghers often describe and map plant communities in terms of

their structure, general appearance and coverage of the dominant plants.On the map the dark green tones represent Taiga (boreal forest); thelighter green, temperate deciduous forests ; yellow, grasslands ; orange, deserts ;

bright green, tropical rain forests ; and pink, Woodland/shrubland sMediterranean .



Forests are dominated by trees growing close enough together that their leafy

canopies generally touch or overlap as in this German broadleaf deciduous

forest. http://www.abc.net.au/news/photos/2007/04/10/1893352.htm



Forests require aconsiderable amountof moisture, but

can survive under

a wide range oftemperatures.There are severalforest biomes.

sa e woo ores

Mendocino County, CAhttp://www.rffi.org/Usal-location.html



Although each biome is named for a dominant vegetation association, the concept

also includes all forms of animal life as well as the relationship between living thingsand other aspects of the environment such as soils, topography, and climate .

http://www.anoige.ie/Editor/assets/kangaroos.jpg



The tropical rainforest biome is found in areas of year-round heat and moisture

as here on the Amazon River. These forests, sometimes called selva , arecomposed of numerous species of tall, broadleaf evergreen trees.

http://www.digi-hound.com/wp/img_wp2/amazon2.jpg



Tropical regions with a marked dry season support similar forests, but in

these regions the tree canopies tend to be more open and many of the treespecies mat lose some or all of their leaves during the dry season. This

biome is referred to as the tropical monsoon forest or the tropical

deciduous forest. Trinidad during the dry season.http://commons.wikimedia.org/wiki/Image:Chacachacare_dry_forest_3.JPG



Mid-latitude forests are adapted to seasonal changes in temperature and arecomposed of fewer tree species than are found in tropical forests. Lower LewisRiver Falls, Gifford Pinchot National Forest, Washington .By Mauz Khatree



Broadleaf deciduous forests Once covered most of the eastern

U.S., Europe, and eastern Asia.These are all humid regions withcool-to- cold winters and mild-to-hotsummers. Giant panda

(Ailuropoda melanoleuca ),

Qin Ling Mountains, Sichuan, Chinahttp://www.worldwildlife.org/wildworld/profiles/terrestrial/pa/pa0434_full.html



Middle-latitude coniferous forests are particularly extensive

In North America. “Bluebells in a Coniferous Forest”www.cofnod.org.uk/piclib.asp?lang=2



The boreal forest is a coniferous forest adapted to harsh sub-artic regions.



The taiga is a biome that borders the boreal forest, separating it from the tundra.

The taiga is park-like, with just a few tree species that can withstand the cold

temperatures.



Throughout most temperate zones, as moisture available for plant usedeclines,forests give way to woodlands in which trees are lower in

height and spaced further apart as you can see in this photo of Acacia

trees in the Southern Highlands of Tanzania.http://www.worldbotanical.com/african_plants.htm



Shrublands , represented by this assemblage of shrubs,`

and small trees, is representative of many regions of southern Africa.



Because many of the shrubland plantsin the tropics and subtropics have thorns,this type of low, thick woody vegetation

cover is sometimes referred to as thorn forest .Umbrella Thorn Acacia , Africahttp://www.veeriku.tartu.ee/~ppensa/plant_adaptation.html



A woody drought-resistant vegetation found along the shores of the MediterraneanSea and in other subtropical regions with mild, wet winters and hot, dry summers.This biome, which has been greatly modified by human occupation, is probably

Best known as Mediterranean woodland and shrub although it may also be

called sclerophyll forest or chaparral . Santa Susanas Mts.,CA.http://en.wikipedia.org/wiki/Image:Santa_Susana_Mts.jpg



The classic savanna , landscape of grasses and scattered trees is seen here

in Kenya’s Masai Mara National Park. The grassy savanna is one of several

variations found in the tropical grassland biome.http://kentsimmons.uwinnipeg.ca/16cm05/1116/16biomes.htm



Mid-latitude grasslands include prairies characterized by tall to mediumgrasses (tall grass prairies) with trees along the water courses…Tallgrass Prairie Preserve, Northern OK.www.netl.doe.gov/.../FEW0067.htm



…. And steppes of drier regions where short grasses

frequently grow in bunches (shortgrass prairies) ashere on the Anatolian Plateau in Turkey.

guest-chef.com/hollychase/guiding-in-turkey/



Deserts are aria regions where bare ground shows between widely spaced

individual plants. Some areas as rock faces and sand dunes may be barren,Sonoran Desert, Arizona.www.bedrick.org/album.html



Tundra is the low-growing, largely herbaceous

vegetation of artic regions

and mountainous heights. Herea musk ox has been grazing on this seasonalfood source. Much of the tundra is undergoinga “meltdown” of the underling permafrost.



Reducing the complexity of world natural vegetation into a few broad categories

requires extensive generalization.

The concept of biomes is merely a useful way to organize information as aprelude to gaining more understanding of the great diversity of life on earth.

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