BIOLOGY 1AL Chapter Notes - Chapter 55: Terrestrial Ecosystem, Nitrogen Fixation, Bioremediation
Document Summary
Chapter 55 energy flow and chemical cycling in ecosystems. Physical laws govern energy flow and chemical cycling in ecosystems: ecosystem consists of all organisms in community and all abiotic factors with which they interact. The law of physics and chemistry apply to ecosystems, particularly regarding the conservation of energy. Energy is conserved by degraded to heat during ecosystem processes: chemical elements enter and leave an ecosystem and cycle within it, subject to the law of conservation of mass. Inputs and outputs are generally small compared to recycled amounts, but their balance determines whether the ecosystem gains or loses an element over time. Gross primary production is the total energy assimilated by an ecosystem in a given period: net primary production, the energy accumulated in autotroph biomass, equals gross primary production minus the energy used by the primary producers for respiration.