Abiotic and biotic factors

Video transcript

Hello, welcome to video 5. By now you should know a little bit about the Field of Mars Reserve site that you will be studying in your excursion. Right now we're going to have a look at the abiotic and biotic factors that can contribute to the functioning of an ecosystem so that when you're in the field you'll know what to look for. Here are some of the abiotic or non-living factors that influence an ecosystem. 

Light intensity is the amount of visible life that is present in an area. Depending on where you're standing on the forest floor, the light may vary due to the canopy cover or shrub layer. 

Air temperature is a measure of how hot or cold the air is. This should be recorded in the forested area rather than in the areas of human impact, such as the track. 

Aspect refers to the compass direction that the slope of the site is facing. This is important as it influences how much sun the plants are getting and their exposure to different winds. 

Slope is the angle of the incline at the site. Generally the steeper the slope the more potential for erosion to occur. 

Wind speed is the rate at which air is moving in a particular area and can affect the growth, reproduction and distribution of plants. It is important to remember that the wind speed at ground level is often different at the canopy level. 

Relative humidity is a measure of how much water vapour is present in the air. 

Soil temperature is the measure of how hot or cold the soil is. This can affect the germination and other processes in plants.

Soil pH is a measure of the acidity or alkalinity of the soil with the optimal pH for most plants being slightly acidic. 

Soil moisture is the quantity of water present in the soil and can vary depending on the area you are measuring, with more moisture expected to be around the base of plants. 

Soil texture is determined by feel and records the amount of clay, sand or silt that is present in the mineral part of the soil. 

Parent material is the underlying geological material that forms the soil of an area.

The biotic or living factors that affect an ecosystem are many and varied with living things working both with and against each other in order to survive. Interactions between living things are all at play even if we can't always see it. But the particular way in which an organism interacts with other living things will depend on whether they are producer, a first order consumer, a second order consumer or a decomposer.

Hopefully now you should be able to recognise these factors when you're out in the field. In later videos you are going to be shown how to use various instruments so that you can record these factors when you're at our study site.

End of transcript.