Biomes in South Africa

Only available on StudyMode
  • Download(s): 38
  • Published: May 20, 2013
Read full document
Text Preview
Climate, vegetation and fire influence positive and/or negative actions imposed on one another. Climate affects vegetation by means of any form of precipitation (rain, snow, fog, etc). Climate also affects the different types of vegetations that will burn after long periods or seasonally due to the variables of precipitation. Fires can be caused through natural impacts or through human endeavors. Fires usually arise after long dry hot periods in windy weather when humidity is relatively low. Under such extreme conditions intense fires occur. These fires can spread to far distances with burning everything in its path. Lightning is another natural way to cause fire. Human activities in contrast either deliberately or unintentionally ignite fires. With respect to the deliberate fuelling of fires, certain biomes require fire to germinate and adapt to living under these conditions, therefore humans have to ignite fires to maintain the routine of fire in fire-scarce biomes.

The biomes of South Africa that fire plays the most important role in are the Fynbos, Savanna, and Grassland biomes. There are four other biomes that rarely burn. Fire is the most important in the Fynbos biome; the reasons will be touched upon in the following paragraph.

Fynbos (fine-leaved bush) biome

This biome describes evergreen scrublands with a deficiency in trees and grasses. There are two major types of vegetation: Fynbos and Renosterveld. There is high endemism of 80%. The range of the mean annual precipitation is between 250-800mm. Due to the high rainfall occurrence fires are then important to allow for the specific fynbos vegetation growth. There are several factors influencing fire dynamics in fynbos: global warming, grazing practices, and fire management. Fynbos must burn between 6 and 46 years of age in order to uphold its plant species. With the above said, plants have become adapted to two ways in which to manage fires: re-seeders or re-sprouters. Re-seeders are mostly practiced. Cones encase seeds that are fire-resistant hence protecting the seeds from desiccation and burning completely. These seeds are then released after the fire. The fire enables the seed to then germinate and become adapted to that environment. Most fynbos are flammable due to them containing flammable oils. These oils come from the seeds of the plant which get their nutrients from the soil and precipitation. The parent plant species die after the fire indicating a low life span and reproduction can only occur with seeds there-on-after. There are also many species that are adapted to re-sprout after the fire. Without the presence of fire, the fynbos species will age and die out. To great extents of fire burning, fynbos can become eliminated.

Grassland biome

Grasslands are biomes that dominate in large quantities of grass. Grasslands do not get high rainfall therefore they are said to be semi-arid. Precipitation ranges between 400-1200mm per annum. In the grassland biome fire is regarded as a secondary determinant. Fires and grazing are important factors influencing grass dominance given that under wet conditions it helps prevent trees from thriving in this region. In drier areas, trees may not grow but fire still plays a role in allowing other species to grow as well as recycle nutrients to the soil. Burning of grasslands is prescribed in areas of high biomass where grassland curing poses a wildfire threat. Farmers and nature conservators also burn grass masses to provide grazing and is known as a method called maintenance burning. There is great biodiversity in the grassland biome. These organisms are well-adapted to the environment and are fire-tolerant.

Savanna biome

The savanna biome is identified as a ground layer consisting of grass whilst the upper layer consists of woody plants and a lack of trees. The mean annual precipitation is in the range of 230-1250mm. Grasses fuel fire. The temperatures in savannas are high therefore savannas are...
tracking img