Vegetation
Semi-arid regions usually can't support forests or large vegetation. Semi-arid climates are dominated by small plants, usually grasses, shrubs, and small trees. Certain plants in semi-arid regions may have some of the same adaptations as desert plants, such as thorny branches or waxy cuticles to reduce evaporative water loss through their leaves.
Animals
The animals in a semi-arid region are usually those which are adapted to grassland ecosystems. This usually means large ungulates or herd animals such as bison, antelope, gazelle, zebra, and so on. Predators such as wolves, lions, jackals or coyotes are also found in these regions, depending on the continent in question and whether the area is sub-tropical or temperate.
Hot and Cold Semi-Arid Climates
Hot semi-arid climates are found in the tropic or sub-tropics, often on the fringe of sub-tropical deserts. They have very hot summers and mild or warm winters. Cold semi-arid regions are usually found in temperate zones. Furthermore, they are more likely to occur inland, away from large bodies of water. Summers are usually hot and dry, and winters are often cold enough for snow.
Examples
Hot semi-arid climates are found in much of the Australian outback, as well as parts of southern Africa, and a large area of land on the southern edge of the Sahara Desert. Cold semi-arid climates include the Great Plains of North America, as well as large areas of Mongolia and Kazahkstan.