They are distinct biomes but frequently border each other.
Bacteria and fungi are the main decomposers in a desert as well as in other biomes.
The dominant plants of the desert biomes would depend on what desert you are referring to. In the Mojave, for instance, the more dominant plants would be cacti, mesquite trees and Joshua trees. In other deserts, only sand exists. The dominant plants of the grassland biomes is grass.
Deserts are hot and rainforests are temperate.
There is no such thing as a Savanna Desert. The savanna is a distinct biome from a desert. It is a transition zone between two biomes. In this case, between the Sahara Desert and the Serengeti plains (grasslands). Savannas generally receive more rainfall than a desert.
Trees do grow in the desert. They are just not as common in deserts as in some other biomes.
Australia has forests as well as deserts and a number of other biomes.
In North America there is no such species as the 'desert porcupine.' There is one species that happens to sometimes live in the desert as well as a number of other biomes.
The sun is the major source of energy in the desert as well as most other biomes on earth.
No, Africa contains several deserts: The Sahara which is subdivided into other deserts The Namib Desert The Kalahari Desert Africa also has savannah, grasslands, rainforests and other biomes besides desert.
The deserts usually have fewer numbers of amphibians than most other biomes.
The 2 biomes that are not in Canada are the tropical forest and the desert. The other 4 are definitley in Canada. *Edit* Actually Canada has a very little desert biome in southern B.C. so I think it could be tropical rain forest and chaparral. It depends which list of biomes you are choosing from.