Marsh•A marsh is a wetland that is dominated by herbaceous

rather than woody plant species. Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds.

•Marshes provide habitat for many types of plants and animals that have adapted to living in flooded conditions

•Types of marshes •Marshes differ depending mainly on their location and

salinity. The three main types of marsh are salt marshes, freshwater tidal marshes, and freshwater marshes.

•Salt marshes •Saltwater marshes are found around the world

in mid to high latitudes, wherever there are sections of protected coastline. They are located close enough to the shoreline that the motion of the tides affects them, and, sporadically, they are covered with water.

•Freshwater tidal marshes •Although considered a freshwater marsh, this

form of marsh is affected by the ocean tides. However, without the stresses of salinity at work in its saltwater counterpart, the diversity of the plants and animals that live in and use freshwater tidal marshes is much higher than in salt marshes.

•Freshwater marshes •Ranging greatly in both size and geographic

location, freshwater marshes make up the most common form of wetland in North America.

Sea level•Sea level is generally used to refer to mean sea level (MSL), an average level for the surface of one or more of Earth's oceans from which heights such as elevations may be measured.

Changes in sea level•Sea level may vary with changes in climate. During past ice ages, sea level was much lower because the climate was colder and more water was frozen in glaciers and ice sheets.

Global warming and sea levelAn increase in the earth's average

atmospheric temperature that causes corresponding changes in climate and that may result from the greenhouse

effect.

Praire•Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type.

•Formation •The formation of the North American Prairies started with the upwelling of the Rocky Mountains. The mountains created a rain shadow that killed most of the trees

•Types •Prairie in North America is usually split into three groups: wet, mesic, and dry.[7] They are generally characterized by tallgrass prairie, mixed, or shortgrass prairie, depending on the quality of soil and rainfall.

•Wet • In wet prairie, the soil is usually very moist most of the growing season and has

poor water drainage. This can possibly contain a bog or fen, since it often has plentiful stagnant water. This type of prairie has the best type of farming soil.

•Mesic •Mesic prairie has good drainage, but good soil during the growing season. This

type of prairie is the most often converted for agricultural usage, consequently it is one of the more endangered types of prairie.

•Dry •Dry prairie has somewhat wet to very dry soil during the growing season because

of good drainage in the soil. Often, this prairie can be found on uplands or slopes. Dry soil usually doesn't get much vegetation due to lack of rain. This is the dominant biome in the Southern Canadian agricultural and climatic region known as Palliser's Triangle.

Steppe•Ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes.Usually characterized by a semi-arid and continental climate. Summer: Up to 40 °C winter: –40 °C

Types of Steppes•Temperate steppe: the "true" steppe, found in continental areas of the world.

•Subtropical steppe: a similar association of plants that can be found in the driest areas; it usually has a short wet period

Steppes around the world

1. Eurasian steppe, from Hungary to China. It reaches almost one-fifth of the way around the Earth.

2. The dry shortgrass prairie, from the U.S. state of Texas to Canada.

Mountains

Landform that rises high above the surrounding terrain in a limited area. They are made from rocks.They are higher than 600 metres.

How are mountains formed?•Mountains are formed by slow but gigantic movements of the earth's crust

Types of MountainsThere are three main types of mountains:•Volcanic•Fold•Block

Greatest Mountains1. Mount Everest, Nepal and Tibet; 8848

mts.2. The Matterhorn, emblem of Swiss Alps.

Switzerland and Italy; 4478 mts.3. Table Mountain, South Africa; 1086 mts.4. K2, China and Pakistan; 8611 mts.5. Mount Kailash, Tibet; 6638 mts.