Chapter 23 Terrestrial Ecosystems

What are the three major vegetation zones of the taiga?

1- Forest-tundra ecotone (with open strands of stunted spruce, lichens, and moss) 2- Open lichen woodland (with strands of lichens and black spruce) 3- Main boreal forest (with continuous strands of spruce and pine broken by poplar and birch on disturbed areas)

A 10km^2 area of tropical rain forest can contain?

1500 species of flowering plants and 750 species of trees

What is the average time for leaf litter to decompose?

24 weeks

What percent of landmass do arid regions occupy? Between where?

25-35 percent. Between 15 and 30 degrees latitude where air from the ITCZ forms semi-permanent high-pressure cells which dominate the climate of tropical desert

Forest covers approx. ___% of Earth's surface

35%

Grasslands are tallest and most productive when mean annual precipitation is greater than _________ and mean annual temperature is above ________

800mm, 15 degrees Celsius

What is a shrub?

A plant with multiple woody, persistent stems but no central trunk and a height from 4.5-8m (under severe environmental conditions many trees don't exceed this size)

Savanna

A range of vegetation types in the drier tropics and subtropics (tropical grassland) characterized by a ground cover of grasses with scattered shrubs or trees

What kind of life do deserts support?

A wide variety of plants and animals (mammals mainly herbivores who tend to be generalists or opportunists that eat seeds; in some cases carnivores have mixed diets that incorporate leaves and fruits)

Much of the diversity of vegetation cover of Grasslands reflects differences in the ______ and _____ of precipitation.

Amount and reliability

What is the end of the growing season for broadleaf deciduous forest marked by?

Autumn colors (resume growth in Spring when temperatures are higher and days longer)

Annual grassland

Grassland in California dominated by exotic annual grasses that reseed every year, replacing native perennial grasses. Associated with a Mediterranean climate (rainy winters, hot/dry summers). Growth occurs in early Spring, most plants are dormant in the summer

Grasslands evolved under the selective pressure of ________

Grazing

What did the African grassveld used to support? Now what does it have?

Great migratory wildebeest herds, zebra, and carnivores. Now the great herds are destroyed and replaced with sheep, cattle, and horses.

Grasslands support a diversity of animal life dominated by _________ species

Herbivorous (most common are large grazing ungulates and burrowing mammals)

What are of great ecological and economic importance in boreal forests?

Herbivorous insects like the spruce budworm (major source of food for summer birds but tend to kill large expanses of forest)

The Eurasian steppes and Argentine pampas lack...

Herds of large ungulates

Problems in industrial forestry are?

Industrial forestry approach treats trees as a crop rather than trying to maintain a forest ecosystem. Forest is clear-cut; the site is sprayed with herbicides, planted/seeded with a single species, and then clear-cut and planted again. This occurs in some national forests and is not sustained-yield management. The economic focus is on the resources, not the forest as a biological community. A managed stand of one or two species of trees is not a forest in the biological sense. Rarely will a naturally regenerated forest, and certainly not a planted one, support the diversity of life found in old-growth forests. By the time the trees reach economic or financial maturity—based on the type of rotation—they are cut again.

Broadleaf evergreen is becoming increasingly present where?

Korea, southern China, the wet foothills of the Himalayas, and Japan

What is a plant characteristic used to further classify forest and woodland ecosystems?

Leaf form

What are some plants conspicuous to tropical rain forests?

Lianas (climbing vines), and epiphytes

The Australian Mediterranean shrub community is called ______ and is dominated by _______ which can quickly become a monoculture

Mallee; Eucalyptus

What kind of organisms do Savannas support?

Many herbivores, insects, carnivores, and scavengers

What kind of shrubs are in Chile?

Matorral shrubs which are mostly evergreen

Biome types form in response to a distinctive pattern based on...

Mean annual precipitation and temperature

Mean annual precipitation decreases with...?

Mean annual temperature decreases (decreases from equator to poles, but seasonal variation of temperature increases in this direction - reflects the systematic latitudinal pattern of change in environmental conditions as a direct result of seasonal variations and solar radiation influx)

Climate of lowland forest zone

Mean annual temperatures typically exceed 25% with an annual range less than 5 degrees Celsius.

Where do the temperate deciduous forests reach their greatest development in the _____ _____ where the number of trees is unsurpassed by any other temperate area in the world

Mesic forest

Where do natural grasslands occur?

Midlatitudes in the midcontinental regions (where annual precipitation declines as air masses move inward from coastal environments) like the prairies of North America and the steppes of central Eurasia (for the northern hemisphere), the pampas of Argentina and the veld of the high plateaus of southern Africa (for the southern hemisphere)

The ___ and ___ climate of the Pacific Northwest supports a highly productive coastal forest extending along the coastal strip from Alaska to northern California

Mild and moist

What are the several deciduous forest types of eastern North America?

Mixed mesophytic, beech-maple, pine-hemlock/northern hardwood, maple-basswood, oak-chestnut/central hardwood, magnolia-oak, oak-hickory

What controls the density of woody vegetation in Savannas? Yearly plant activity cycle and subsequent productivity?

Moisture as a function of both rainfall (amount and distribution) and soil (texture, structure, and water-holding capacity). Seasonal precipitation and changes in available soil moisture affect the plant activity cycle and subsequent productivity

What is cryoplanation? Why is it important for the tundra?

Molding of the landscape via frost action. It is more important than erosion in wearing down the Arctic landscape

Cerrado

More densely wooded areas of savanna in South America

Where do you find savannas?

On land surfaces of little relief (like old plateaus), interrupted by escarpments and dissected by rivers.

What are buttresses?

Plank-like outgrowths that large trees form to serve as prop roots for support in shallow soil

Removal of trees in clear cutting increases... (cascade of effect)

Radiation (including direct sunlight) reaching soil surface--> Increase in soil temperature-->Promotion of decomposition-->Increase in net mineralization rates-->Increase in nutrient availability at the same time demand is low and NPP is low due to plant removal-->Dramatic increase in leaching (basically all this happens due to the decoupling of nutrient release in decomposition and nutrient uptake in net primary productivity)

What does coppice mean?

Resprout from the stump

Where are the forest ecosystems for the Southern Hemisphere?

Southern Chile (broadleaf evergreen), New Zealand (evergreen forests), Tasmania, and parts of southeastern Australia

Microenvironments associated with tree canopies can influence...

Species distribution, productivity, and soil characterisitics

What is the key concept in forestry?

Sustained yield

Where is the easternmost limit of the Mediterranean areas?

Syria, Lebanon, and Israel

What are the native grasslands of North America?

Tallgrass prairie, Mixed-grass prairie, and shortgrass prairie

What are some differences among deserts?

Temperature, moisture, soil drainage, topography, alkalinity, salinity (these affect vegetation cover, dominant plants, and groups of associated species)

What is the largest most continuous region of rain forest in the world? Second? Third?

The Amazon basin of South America; Southeast Asia; West Africa (around the Gulf of Guinea and the Congo basin).

Give some examples of cool deserts

The Great Basin of North America, the Gobi, Takla Makan, and Turkestan deserts of Asia

What are the three desert regions of South Africa?

The Namib, The Karoo, and the Kalahari

Globally, about half of the forest that was present under post-modern climatic conditions (and before the spread of human influence) has largely disappeared due to...

The impact of human activities (spread of agriculture, animal husbandry, harvest of forests for timber or fuel, expansion of populated areas)

What is considered northern desert scrub?

The northern arid region of the Great Basin of North America

The broad categorizations of the major terrestrial biomes reflect...?

The relative contribution of trees, shrubs, and grasses (these exhibit fundamentally different patterns of carbon allocation and morphology)

As temperatures become more extreme and the growing season shorter, trees can no longer be supported and...

The short-stature shrubs and sedges (grass-like plants of the family Cyperaceae) characteristic of the tundra which dominates the landscape ecosystems of the arctic region

Climatically what is the taiga like?

The taiga is dominated by a cold continental climate with strong seasonal variations. Summers are short, cool, and moist. Winters are long, harsh, and dry with prolonged snowfall. (Interior Alaska and central Siberia experience some of the most extreme seasonal temperature fluctuations)

Differences in climate, bedrock, and drainage for forests are reflected in ....

The variety of soil conditions present (Alfisols, inceptisols, and ultisols)

Explain tundra vegetation

The vegetation structure of the tundra is simple, with few species and slow growth. (Only species that can withstand constant soil disturbance, buffeting by the wind, and abrasion by wind-carried particles of soil and ice can survive) Arctic plants propagate almost entirely by vegetative means but viable seeds hundreds of years old exist in the soil

Most leaf litter decomposes in what season for Savanna's?

The wet season

What are some plant adaptations to drought conditions?

They could have root systems that reach the water table (like mesquite and Tamarix) which allows them to be independent from water supplied by rainfall

What are islands of fertility in deserts?

Areas underneath established plants that develop due to high litter input and enrichment by wastes from animals that seek shade

Arid hummock grasslands

Areas with less than 20cm rainfall

Desert is a general category of...?

Areas with scarce plant cover

4 types of Australian grassland

Arid tussock; Arid hummock; Coastal; Subhumid

What kind of soils in deserts?

Aridisols and entisols

Cool deserts and highly elevated hot deserts are dominated by what plants?

Artemisia and chenopod shrubs (so these areas may be considered shrub steppes or desert shrub)

Where are Mediterranean climates found?

Between 30 and 40 degrees latitude

In the North American Grasslands what helped to develop and maintain ecological structure of the shortgrass prairie?

Bison, Gophers, mound-building harvester ants

Boundaries between biomes can be...?

Broad and indistinct

What are the two sub-classifications of the evergreen leaf type?

Broadleaf evergreen (characteristic of environments with no distinct growing season where photosynthesis and growth continue year round, warm and wet climates with no direct seasonality) and Needle-leaf evergreen (characteristic of environments where the growing season is very short - northern latitudes- or nutrient availability severely constrains photosynthesis and plant growth)

Progression with increased seasonality and decreased temperatures

Broadleaf evergreen forests-->Winter-deciduous (now in temperate deciduous forest)

Where is the largest proportion of tropical dry forest?

Africa and South America (to the south of zones dominated by rain forests)

Where is the boreal forest of North America?

Alaska, Canada, and northern New England

Subhumid grasslands

Along coastal areas where annual rainfall is between 50-100cm

Where is the Asiatic broadleaf forest found?

Eastern China, Korea, Taiwan, and Japan

The five vertical layers of the tropical rainforest are?

Emergent trees, upper canopy, lower canopy, shrub understory, and a ground layer of herbs and ferns.

Deciduous leaves are characteristic of..?

Environments with a distinct growing season

Steppes

Eurasian grasslands that extend from eastern Europe to western Siberia and China. They are treeless except for ribbons and forest patches, and are divided into 4 belts of latitude from the mesic meadow steppes in the North to the semiarid (mesic) grasslands in the South

Velds

Extensive grasslands in the East of the interior of South Africa, largely confined to high terrain

Other characteristics of tropical rain forest?

High plant and animal life diversity (accounts for more than 50% of all known plant and animal species- tree species number in the thousands), covers 6% of land surface. Nearly 90% of nonhuman primate species live here.

In the Rocky mountains explain what grows at high, middle and lower altitudes

High- Engelmann spruce, Middle- Douglas fir, Lower- Ponderosa pine and lodgepole pine

What is the Mediterranean climate like?

Hot, dry summers (at least 1 period of protracted drought, these summers are the result of seasonal change from the semi-permanent high pressure zones over tropical deserts), and moist winters (65% annual precipitation during winter)

Forest arthropods spend most of their lives...

In a single stratum

Arid tussock grasslands

In the northern part of Australia where rainfall averages 20-50cm

Temperate deserts are located where?

In the rainshadow of mountain barriers or far inland (Mostly in the Northern Hemisphere but also located in the subtropical high pressure belt in the Southern Hemisphere that mirrors the Northern Hemisphere)

Coastal grasslands

In the tropical summer rainfall region

Why is the productivity of grasslands complicated by temperature?

Increase in temperature can have a positive effect on photosynthesis but in reality reduce productivity by increasing water demand

Life present in the tundra

Invertebrates near the surface (segemented whiteworms, flies etc...). Dominant invertebrates are herbivores (ex: lemmings, arctic hares, Caribou, Musk oxen, some birds). Major arctic carnivore: wolf (secondary carnivores: Arctic fox, Snowy owls)

What are temperatures like in temperate deserts?

It can be high during the Summer and freezing during winter months

What is the floor of a tropical rain forest like?

It is thinly laced with roots, both large and small, which forms a dense mat on the ground.

What species is the dominant grazer in Australia?

Kangaroo

Dry tropical forests undergo a dry season whose length is based on ________

Latitude (The most distant the forest is from the equator, the longer the dry season)

How is primary productivity in deserts?

Low because of infrequent rainfall and high rates of evaporation

NPP boreal forest

Low with slow rates of decomposition due to cold and wet conditions (organic matter accumulates)

Pampas

Major grasslands in Southern Africa and Southern South America. Temperate and dominated by bunchgrasses; much of the moister pampas are under cultivation

What are coniferous forests dominated by?

Needle-leaf evergreen trees (found primarily in a broad circumpolar belt across the Northern hemisphere and mountain ranges where lower temperatures limit the growing season)

Moving poleward, temperate deciduous forest gives way to...

Needle-leaf-dominated forests of the boreal region (conifer forest or taiga)

What do North American and Australian shrub communities support?

North America- mule deer, coyotes, jackrabbits, sage grouse. Australian mallee- birds, kangaroo, wallaby

What are the European coniferous forests dominated by?

Norway spruce

The greatest concentration and variety of life in the forest occurs...

On or just below the ground layer (many animals remain in the subterranean stratum, others burrow into the soil or litter for shelter or food, large mammals live on the ground layer, birds move freely among several strata but tend to prefer one)

Boreal forest animals

Caribou, moose, arboreal red squirrel, wolf, lynx, owls, and a nesting ground for migratory neotropical birds

The ____ and _____ of forest loss are different for different regions and forest types

Cause and timing

What helps to contribute to the development of arid coastal regions too?

Cold ocean currents

What are the characteristic soils of tropical rainforests?

Oxisols.

What are 2 major large herbivores of the pampas?

Pampas deer and the guanaco (small relative of the camel)

Most of the taiga is under the controlling influence of...?

Permafrost

Explain permafrost

Permafrost is the perennially frozen subsurface that develops where the ground temperatures remain below 0C for extended periods. It may be hundreds of meters deep. (Upper layers may thaw in summer and refreeze in winter) Because the permafrost is impervious to water, it forces all water to remain and move above it (The ground stays soggy even though precipitation is low, allowing plants to exists in the driest areas).

What are shrublands?

Plant communities where shrub growth form is dominant or codominant (difficult to categorize)

What are the two broad categories of leaves based on their longevity?

Deciduous (leaves that live for only a single year or growth season) and Evergreen (leaves that live beyond a year)

What is primary productivity like for forests and when do leaves fall?

Primary productivity varies (influenced by temperatures and length of growth season). Leaves fall in autumn.

In Mediterranean shrubland, similarity in habitat structure has resulted in?

Pronounced parallel and convergent evolution among bird species and some lizard species (Chile and California)

The thickened cuticles, glandular hairs, and sunken stomata of the sclerophyllous vegetation helps...

Reduce water loss

The highly developed _____ layer of grasslands can make up more than half of the total plant biomass and typically extends fairly deep into the soil

Root

What is the most visible feature of grassland?

Tall, green, ephemeral herbaceous growth that develops in Spring and dies back in Autumn.

Where are coniferous forests in North America?

The Rocky, Wasatch, Sierra Nevada, and Cascade mountains

What is the largest desert in the world?

The Sahara

What is both the largest expanse of conifer forest and the largest vegetation formation on Earth?

The boreal forest or taiga (land of little sticks) which encompass the high altitudes of the Northern Hemisphere (11% Earth's terrestrial surface)

Characterize the Great Basin

The climate is continental. It has warm summers, prolonged cold winters. Vegetation falls into two main associations sagebrush (dominated by Artemisia) and shadscale (a C4 species) and other chenopod shrubs

Woodland and savanna ecosystems are categorized by?

The codominance of grasses and trees (or shrubs).

What has changed the grasslands of Australia?

The introduction of fertilizers, nonnative grass, legumes, and sheep grazing

What else can influence the occurrence of a biome in a location?

Topography, soil type, and disturbance

Rotation time depends on...?

Tree species, site conditions, type of management, and intended use of harvested trees

Areas of Central America, northern Australia, India, and Southeast Asia are also classified as...?

Tropical Dry Forest

Types of Tundra

Tundra (a) has up to 100 percent plant cover and wet to moist soils; Polar desert (b) has less than 5 percent plant cover and dry soil

Mixed-grass prairie

Typical of Great Plains, is composed largely of needlegrass-grama grass (Bouteloua-Stipa). Characterized by great variation in precipitation and a mixture of largely cool-season shortgrass and tallgrass species.

Main type of soil for forested regions

Ultisols (due to seasonal soil moisture deficits)

Mediterranean shrublands lack...and therefore are?

Understory and ground litter; so they are highly flammable (lots of species have seeds that require heat and scarring from fire to induce germination, without the fire the shrublands get more potentially volatile as they grow and build large fuel loads)

What are the 4 strata of highly developed, unevenly aged deciduous forest?

Upper canopy (with a dominant tree species), lower tree canopy/understory, shrub layer, ground layer (herbs, ferns, and mosses) (diversity of animal life is associated with these 4 strata)

Describe the climate of the tropical rain forest?

Varies geographically but is typically characterized by a mean temperature of all months exceeding 18 degrees Celsius and a minimum monthly precipitation above 60mm.

Where do Grasslands do the least well?

Where precipitation is lowest and temperatures are high

What are the two further sub-classifications of the deciduous leaf type?

Winter-deciduous (characteristic of temperate regions), and Drought-deciduous (characteristic of environments with seasonal rainfall especially in subtropical and tropical regions). Leaves are lost in response to low temperatures; leaves are lost in response to drought conditions.

Lowland tropical forest of peninsular Malaysia contains...?

~7900 species

What are some foresting techniques (silvicultural and harvesting techniques)

1) Clear- cutting (involves removing forest and reverting it to an early stage of succession; postharvest management varies and clear cut areas can be badly disturbed by erosion which can affect adjacent aquatic communities too, herbicides also used often which compete with seedlings for resources) 2) Seed-tree (shelterwood) (regenerating a new stand by removing all trees from an area except a small # of seed bearing trees. Similar to clear cutting, generally not enough trees left to affect microclimate of harvested area, advantage is that the seed source for natural regeneration is not limited to adjacent strands which can improve distribution/stocking of seedlings and mix species desirably) 3) Selection cutting (mature single trees or groups of trees scattered throughout the forest are removed. Produces only small gaps in the forest canopy. Can minimize scale of disturbance caused by direct tree removal, but trails and roads necessary to provide access can cause lots of disturbance to plants and soils)

Conditions for sustainable harvesting

1) For a tree stand to be considered to be in an operative state (economically available), minimum thresholds must be satisfied for the harvestable volume of timber per hectare and average tree size (varies) 2) After harvesting, significant time must pass for the forest to regenerate (to return to the level of biomass it reached at the time of the previous harvest) (paper products have a short rotation period whereas timber is much longer) 3) Sustained forestry of hardwood species (which require decades for their rotation time) works best in areas where blocks of land are designated by age

What are the conditions unique to the Arctic tundra a product of?

1) Permanently frozen deep layer of permafrost (Permafrost chills the soil, retarding plant growth, limits soil microorganism activity, and diminishes soil aeration and nutrient content) 2) Overlaying active layer of organic matter and mineral soil that thaws each summer and freezes in winter 3) Vegetation that reduces warming and retards thawing in summer

Tropical rainforests are restricted primarily to the equatorial zone between latitudes...

10 degrees N and 10 degrees S (where temperatures are warm throughout the year and rainfall occurs almost daily)

What creates the unique symmetrically patterned landforms of the tundra?

Alternate freezing and thawing of the upper layer of soil (frost pushes stones and other material upward and outward from the mass to form a patterned surface of frost hummocks, frost boils, earth stripes, and stone polygons)

Main type of soil for areas with volcanic activity

Andosols

Progression with increased seasonality and drier temperatures

Broadleaf evergreen-->Drought-deciduous-->Woodlands and Savannas-->Shrublands and desert

How do animals adapt to drought conditions?

By changing behavior or could even adapt to become nocturnal (in extreme drought some animals do not reproduce)

What is the sclerophyllous shrub community of North America called?

Chaparral

Why has deciduous forest largely disappear?

Clearing over centuries for agriculture

All 5 Mediterranean regions have?

Communities of xeric broadleaf shrubs, dwarf trees, and a herbaceous understory

What is the reason why natural grasslands have shrunk to 12% their original size?

Conversion to cropland and grazing lands

The largest area of Mediterranean ecosystem forms a ______________ ________ around the Mediterranean Sea from southern Europe through North Africa

Discontinuous belt

What is the soil like in Mediterranean regions?

Diverse but typically alfisols (nutrient-deficient, low temperatures limit litter decomposition, low soil moisture)

Tallgrass prairie

Dominated by big bluestem (Andropogon gerardi) growing 1 meter tall with flowering stalks 1-3.5m tall. Once ran north and south adjacent to the deciduous forest of eastern North America; presence maintained by fire; has largely been destroyed by cultivation

Short-grass prairie

Dominated by sod-forming blue grama (Bouteloua gracilis) and buffalo grass (Buchloe dactyloides). The westernmost grasslands of the Great Plains characterized by infrequent rainfall, low humidity, and high winds; dominated by shallow-rooted, sod-forming grasses

What recurs in temperate grasslands?

Drought

Plants and animals in the desert have what common characteristic?

Drought adaptations via drought evasion or resistance

How does fire affect the taiga?

During periods of drought, fires can affect large portions of the taiga. (Boreal species, both broadleaf trees and conifers, are well adapted to fire) Fire is a source of regeneration

Soil boreal forest

Spodosols with a thick organic layer; mineral soils beneath mature coniferous forests are pretty infertile in comparison

The warm wetter conditions of the tropical rainforest contribute to...?

Strong chemical weathering, rapid leaching of soluble materials, high rates of net primary productivity and subsequent high annual rates of litter input to the forest floor (litter input does not accumulate that much though, yes a lot may fall but the decomposers get to it really fast)

Tundra climate

Strong winds, snow, cold, and widely fluctuating temperatures dominate these mountainous areas Because the atmosphere is thin at high elevations, ultraviolet light is especially intense on clear days Summer soil surface temperature ranges from 40C to 0C. Little permafrost except at very high elevations, so the soil is drier. These areas receive precipitation, but the steep topography induces rapid runoff (and loss) of water.

Three strata of grassland

Tall, green herbaceous growth. Ground layer. Belowground layer.

Biomes are classified based on?

The predominant plant types

Characterize grasses

They maintain a higher proportion of biomass in photosynthetic tissue (leaves) because little energy is required for support tissues (stems)

In the face of increasing demand and declining forest cover, sustainable production of forest resources requires a balance between _____ _______ and ______

net growth and harvest

Natural grasslands occupy regions where rainfall is between ___ and ___ cm a year

25-80

Reasoning behind the different leaf types

Cost of production should be less than the payback

What 3 things cause the formation of solifluction terraces?

Creep, frost thrusting, and downward flow of super saturated soil on sloping ground (soil creep and rocks eventually round off ridges and other topographical irregularities)

What is a frequent hazard during the summer in the Mediterranean regions?

Fire

What are some of the major terrestrial biome types?

Forest (Tropical forest, temperate forest, conifer forest (taiga, and boreal forest)), tropical savanna, temperate grasslands, chaparral (shrublands), tundra, and desert.

Climatic conditions in humid midaltitude regions give rise to?

Forest dominated by broadleaf deciduous trees

Taiga primarily occupies _____ _____ ____ but also is a region of cold lakes, bogs, rivers, and alder thickets

Formerly glaciated land

Tundra

Frozen plain (clothed in sedges, heaths, and willows, dotted with lakes and crossed by streams)

In the Mediterranean region of South Africa, what is the vegetation called and composed of?

Fynbos- broadleaf proteoid and ericoid

What is the largest coniferous tree?

Giant sequoia

What threatens boreal forest?

Global demand for timber and pulp

In regions of the temperate region where precipitation is insufficient to grow trees...

Grasses dominate and this gives rise to the prairies of North America, steppes of Eurasia, and pampas of Argentina.

Where is the boreal forest of Eurasia?

Scotland, Scandinavia, much of Siberia up to northern Japan

What is California chaparral dominated by? Rocky mountain chaparral?

Scrub oak and chamise which are evergreen (not much vertical growth because low moisture support, take up and hold soil back (a significant adaptation)), winter active, summer dormant; winter-deciduous Gambel oak

Tropical Savannas are characteristic of...?

Semiarid regions (warm) with seasonal rainfall and large interannual (year to year) variation in total precipitation. Have a 2 layer vertical structure due to its ground cover made up of grasses and some shrubs and trees. Usually have nutrient-poor oxisols (phosphorous deficiency) or alfisols in drier savanna, entisols in the driest savanna. Have fire-adapted plants due to having a fire regime. Woody vegetation is short-lived.

What are the 5 regions of Mediterranean ecosystems?

Semiarid regions of western North America, regions bordering the Mediterranean Sea, central Chile, cape region of South Africa, and southwestern and southeastern Australia

Characterize shrubs and trees (woody plants)

Shrubs invest fewer resources in stems and other supporting structures than trees. An advantage of woody tissue is increased height and access to light/ability to compete for light. (there is an associated cost of maintenance and respiration) As environmental conditions are less favorable for photosynthesis, trees decline in height and density

Desert grassland

Similar to shortgrass plains but has three-awn grass. Grassland of hot, dry climates, with rainfall varying between 200-500mm, dominated by bunchgrasses and widely interspersed with other desert vegetation