Soil and It's Importance!
Savanna Biome -- Yash Reddy, Katherine Roy, Jackson Beasley
Soil Texture and Composition
- Soil has moderately high porosity, which allows for water to be drained rapidly
- Contains a thin layer of humus, which is the organic component of the soil (formed through decomposition of animal and plant matter)
- The humus provides vegetation with nutrients
- Can be considered Mollisols, which are soils the are used primarily for the purpose of agriculture
- Although the Savanna biome is not known for agriculture, it has the ability to provide grazing lands for animals
- Soils in the Savanna are usually reddish, acid latosols
- The red, rusty color of the biome's soil shows that the soil contains relatively high amounts of iron.
- The soil in the Savannah is very infertile. This is because all of the soil's nutrients are located near the top.
- During the wet season, the rainfall hydrates the soil, but it takes up most of the nutrients in the soil that are necessary for plant life.
- The soil of the Savanna biome contains organisms that can reduce the number of plants they grown each year. The rate at which the bacteria breaks down plant matter is greater the rate at which plants reproduce.
Influences of Human Activities on Soil Fertility
- Although farming is too prevalent in the Savanna biome, it can alter soil fertility
- In the modern day, farmers add nutrients (such as organic/artificial fertilizers) in order to make their crops grow more effectively. These fertilizers, however, can make it difficult for the soil's microorganisms to provide natural nutrients.
- Fertilizers can increase the amount of water pollution, as rainwater can carry these nutrients to nearby lakes and rivers.
- Many famers clear tress and plow up soil to plant crops. When this happens, the soil is more susceptible to rain and wind, and may be carried away through various processes.
- Construction, mining, and other human-led developments cause cause vast amounts of soil loss
The Role of Biotic and Abiotic Limiting Factors in the Savanna
- The seasonal period during which rainfall occurs is a limiting factor to many of the plants and animals in the Savanna biome. Rainfall occurs during a 6 month period, and the other 6 month yields almost no rainfall at all. As a result, the soil can become extremely dry, inhibiting plant growth.
- Dry soil may causes fires, which can destroy many plants and demolish animal habitats
- During the dry season, the availability of water is low, so various organisms have to compete for water
- Prominent biotic limiting factors within the biome are the predator-prey relationships between various animals such as elephants, zebras, lions, giraffes, etc...
The transfers, transformations, inputs, outputs, flows and storages within the soil of the Savanna biome
- The soil contains vast amounts of water (absorbs it from rainfall) and makes it available to plant roots
- Decomposers break down dead matter and transfer the nutrients into the soil
- Soil plays a major role in the water cycle, as it allows water to leave through transpiration and evaporation; absorbs water through precipitation. Additionally, the absorbed water is transferred to the plant's leaves, and is then carried away to various parts of the biome (lakes, rivers, etc...)
- Plants absorb water from the soil in order to grow and perform daily life functions
- Soil provides nutrients such as potassium, phosphorous, and nitrogen. These nutrients move throughout the biome as different levels of the food pyramid interact
Soil Ecosystem Succession and Soil Fertility
- The soil of most biome contains numerous organisms (mainly bacteria) through which nutrients are naturally produced and cycled through various parts of the biome. Ultimately, soil ecosystem succession will take an extremely long time as these organisms inhabit the soil through a lengthy process
- A variety of factors can influence the relationship between soil ecosystem succession and soil fertility: removal of trees, lack of rainfall, lack of nutrients derived from plants and trees, overgrazing, urbanization.
- All of these factors cause the soil to become more susceptible to wind and rain, increase the likelihood through which it is carried away into other parts of the biome.
- Urbanization (specifically farming, construction, and mining) can ultimately decreases overall soil fertility by decreasing the total amount of soil within a region
NPP Average of the Savanna Biome
High levels of net primary productivity in comparison to the actual biomass (dry mass of organic matter) of the vegetation at any one time.
Net Primary Productivity - 3000 Kilocalories per square meter per year
The most productivity is found the period following and during the wet season
At this time, water is readily available to plants
In fact, the productivity during this time can exceed the productivity of forests
How Can Soil Be Considered An Ecosystem?
- Soil itself can be considered an ecosystem because it contains an abundance of living and nonliving components that interact in variety of ways.
- Soil has greater diversity within it than any other ecosystem
- Contains numerous organisms that promote plant growth
- Composed of biotic and abiotic limiting factors, just like any other ecosystem
- Soil is incorporated in numerous ecological cycles including the carbon cycle, water cycle, and oxygen cycle
- Soil provides numerous services to the ecosystem: water filtration, break down of waste
- Soil can manage and detoxify wastes; they can decompose organic compounds. This capability of decomposition is an essential characteristic of an ecosystem.