Every species has an optimum temperature, the further away from the optimum, the smaller the population can be.
In plants and cold blooded animals:
- The lower the temperature, the slower enzymes work therefore their metabolic rate is reduced.
- At high temp, enzymes start to denature, so again population grows slower.
In warm-blooded animals:
- They can maintain a constant body temp, but this requires energy.
- The further from optimum, the more energy used for homeostasis.
- Therefore there is less energy left for growth, so they mature and reproduce slower.
Other abiotic factors
- Higher light intensity = faster rate of photosynthesis.
- Faster rate of photosynthesis = faster growth and more spores or seeds produced.
- More plants = also more animals supported by feeding on them.
- Each enzyme has an optimum pH, further from this it works less effectively due to kinetic energy or denaturation.
- Enzymes are used for metabolic processes, including growth. Optimum pH = more organisms.
Water and humidity
- Water is needed for photosynthesis. No water = no plants = no animals.
- Humidity affects transpiration, and evaporation from animals. In different humidities, differently adapted plants will grow.
Population growth curve
1. Slow growth because a small number of organisms are reproducing rapidly.
2. Rapid growth because large number of organisms reproducing exponentially.
3. Stable state because of a limiting factor on the population i.e predation, food supply. There are small fluctations due to changes in those factors.