2. Currently deserts cover 20% of the world's land.
3. The giant saguaro cactus can grow 50 feet tall and live for for 200 years. 
4. The elf owl can live sometimes in a cactus 

5.  A camel that is thirsty can drink 30 gallons of water, less than 15 minutes.
6.

(2) It is the ecosystem of vegetation and insect/animal life that distinguishes one type of wetland from others.

(3) Wetlands have aquatic plants that are adapted specifically for a type of soil called hydric soil (hydro = water), that is, soil saturated with water either seasonally or on a more permanent basis, and that has a lot of anaerobic (opposite of aerobic, meaning lack of oxygen) conditions.

(4) Wetlands are important and must be preserved because they impact various environmental aspects.  They act as a carbon sink, control floods, provide shoreline stability, and help preserve water purity.

(5) Did you know that wetlands have the most biologically diverse ecosystem among different types of land environments?

(6) Wetlands are found in all continents of Earth, with the exception of Antarctica.

(7) Based on the type of water found, wetlands can be classified as freshwater wetland, brackish water wetland, or seawater wetland.

(8) According to an UN assessment, environmental degradation in wetlands is more prominent than degradation in any other ecosystem.

[9] Wetlands typically have lower economic property value compared to other land types such as prairies, fields, or woodlands.

[10] Did you know that Europe has already lost more than 50% of its wetlands?  This is one reason why European governments have increasingly passed laws to protect wetlands.

(11) The main wetland types are: swamps, marshes, bogs, and fens.

(12) A swamp is a forested wetland with forests or shrubs, and they mostly occur along large rivers and sometimes along large lakes.

(13) Some of the largest swamps are found along the Amazon river basin, the Congo river basin, and the Mississippi river basin.

(14) One important characteristic of swamps is that the water (river or lake) is either stagnant or slow-moving.

(15) Marshes are a type of wetland that is characterized by the presence of herbaceous plants (shrubs such as grasses or reeds) rather than woody plants as in swamps.  

(16) Marshes have unique ecosystems, that act as transition systems to aquatic and terrestrial ecosystems.  They are typically seen at the edges of lakes and streams (not large rivers but streams).

(17) Bogs are wetlands with accumulated acidic peats, and are a characterized by brownish-looking water runoffs.  They are typically found with low mineral content in areas that are colder and with low fertility.  (Think parts of England or Canada; some bogs are found in the Appalachian in the US.)

(18) Fens are a contrast to bogs in that they are found in alkaline, high mineral content areas.  Another name for them is minerotrophic (that is water that has collected minerals and is therefore basic or alkaline) peatlands.  Thus both bogs and fens are peatlands, but with contrasting nature of peat.

(19) The nature of plants in a fen ecosystem depends on the nature and concentration of minerals in the water found in fens!  Some of the largest fens are found in Estonia.

(20) An easy way to remember these ecological types is to append a prefix, like in "forested swamps, grassy marshes, peaty bogs, and minerotrophic fens."