The rocky upper layer of the solid earth is called the "lithosphere". This rocky part includes the brittle upper portion of the mantle and also of the crust. It is bounded by the atmosphere above and of the asthenosphere which is another part of the upper portion of the mantle.
Population is the answer !
Which abiotic factor most likely controls where the plants live in this environment ?
Oxygen levels for aquatic animals
Oxygen from the air and oxygen produced by aquatic plants dissolves in water. Without this, aquatic animals would suffocate and die. Healthy lakes and rivers have high levels of oxygen, and polluted waters often have low levels of oxygen. This pollution means that only certain species can survive there such as sludgeworms. These are bioindicator species because their presence or absence informs us about the condition of the habitat.
Carbon dioxide levels for plants
Carbon dioxide is a reactant in photosynthesis which means plants need it to survive. Areas with higher levels of carbon dioxide are more likely to have healthy plants growing. Farmers often release carbon dioxide within their greenhouses to maximise their crop yield. Woodlands often have higher carbon dioxide levels than open grassland, so many plants living in open areas have evolved mechanisms to overcome a shortage of carbon dioxide.
