Ecosystems - 06/09/17


A level Biology (Chapter 23 - Ecosystems) Note on Ecosystems - 06/09/17, created by Chloe Drewery on 06/09/2017.
Chloe Drewery
Note by Chloe Drewery, updated more than 1 year ago
Chloe Drewery
Created by Chloe Drewery almost 7 years ago

Resource summary

Page 1

Biotic and Abiotic factors An ecosystem is the area where living organisms and non-living conditions interact with each other.  Why do we need to maintain biodiversity?Aesthetic - Artists, musicians and writers get inspired by areas with high biodiversity. It makes people happy.Economic - Resources are used for medicines, etc and used for trading. Areas rich in diversity are thriving with tourism. Ecological - Important for keystone species and maintains ecosystems and habitats. Abiotic factors Soil pH - Causes soil erosion if increased. Any change can disrupt enzymes which intern affects metabolism. Temperature - Species will migrate away from the area to warmer/cooler climates if they change. Also can cause flooding due to ice melting, etc. It also affect enzymes and metabolic reactions. Temperature changes causes a change in seasonal species movement. Also it can trigger early migration as well as blossoming and leaf fall. Light intensity - Affects photosynthesis. Plants grow taller and with bigger leaves to maximise sunlight intake in densely populated areas. Humidity - Increased humidity encourages bacteria and fungi growth which causes disease.  Oxygen - This is in terms of water. Moving water contains more oxygen. The colder the water, the more oxygen it has. Water logging is a problem for organisms too.  Edaphic (soil) - There are three types of soil: clay, loam and sandy. Clay: contains very fine particles which clump together. Loam: good for growing plants. It contains different sized particles ideal for growth. Sandy: Well separated particles, easily eroded.  Biotic factors Disease - Food chain disruption. Invasive species - Introduces disease. They create competition, compete with native species. Such as shrimp in Grafham, red squirrels, and goats in the Galapagos.  Reproduction - More species, more competition for mates, food and territory. 

Page 2

Explain why abiotic factors have a greater affect on the plant species than on animal species in an ecosystem.  Animals are able to migrate to cooler/warmer conditions if there is a temperature change, unlike plants, meaning they are affected by temperature change.  Animals can move to find shelter/search for water. Plants can't regulate their internal temperature so are more affected by temperature change than animals. Many animals are able to survive using a range of food sources unlike plants, meaning they are less affected by a decline in a certain species. 

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