What Are Abiotic Factors of the Grassland Biome?

Overview of Grassland Abiotic Factors

• Though the term "grassland" is typically associated with dry, grassy areas with few trees, in reality, grassland is a very broad term that encapsulates several subclasses of biomes. The World Wildlife Fund recognizes four categories of grasslands; tropical and subtropical grasslands, temperate grasslands, flooded grasslands and montane (mountainous) grasslands. These grassland biomes can be distinguished based on four main abiotic factors: temperature, precipitation, humidity and topography.

Temperature

• Temperature is the first abiotic factor that distinguishes grassland biomes. Grasslands occur in both high-temperature areas near the Equator and mid-to-low-temperature areas nearing subarctic regions. Grasslands are not, however, found in the Arctic regions near the North and South poles. Grasslands that are near the Equator are generally either tropical grasslands (with very warm temperatures year-round) or temperate grasslands (with warm temperatures most of the year). Grasslands that are further from the Equator are mostly temperate grasslands and montane grasslands.

Precipitation

• The second abiotic factor of grassland biomes is precipitation, the amount of water (in the form of rain or snow) that the area receives. Tropical grasslands receive the most rain out of all the grassland biomes, up to 60 inches a year. Temperate grasslands receive much less annual rainfall on average (no more than 40 inches a year). Flooded grasslands, though they are very wet, also receive less annual rainfall than tropical grasslands, around 30 to 40 inches per year. Montane grasslands receive the lowest amount of precipitation, no more than 30 inches per year, and often, that precipitation is in the form of snow.

Humidity

• Humidity, the percentage of moisture in the air, is another abiotic factor of grassland biomes. Tropical grasslands and flooded grasslands are very humid, meaning there is a very high percentage of moisture in the air. Temperate grasslands are somewhat humid, but can also be arid, meaning dry or little moisture in the air. Montane grasslands are typically very arid; however, some are mildly humid.

Topography

• Topography is the final abiotic factor of grasslands. It includes the elevation and land features of the biome. Tropical grasslands vary widely in topography, with some in areas of high elevation and some in areas of very low elevation. They also generally occur in very hilly, uneven landscapes. Temperate grasslands are usually more flat and occur in areas of mid-to-low elevation. Flooded grasslands are almost all flat and in areas of low elevation. Montane grasslands are very mountainous and usually in areas of high elevation.