tailieunhanh - Lecture Biology (7th edition) - Chapter 54: Ecosystems

This chapter explain how the first and second laws of thermodynamics apply to ecosystems; define and compare gross primary production, net primary production, and standing crop; explain why energy flows but nutrients cycle within an ecosystem; explain what factors may limit primary production in aquatic ecosystems;. | Chapter 54 Ecosystems Overview: Ecosystems, Energy, and Matter An ecosystem consists of all the organisms living in a community As well as all the abiotic factors with which they interact Ecosystems can range from a microcosm, such as an aquarium To a large area such as a lake or forest Figure Regardless of an ecosystem’s size Its dynamics involve two main processes: energy flow and chemical cycling Energy flows through ecosystems While matter cycles within them Concept : Ecosystem ecology emphasizes energy flow and chemical cycling Ecosystem ecologists view ecosystems As transformers of energy and processors of matter Ecosystems and Physical Laws The laws of physics and chemistry apply to ecosystems Particularly in regard to the flow of energy Energy is conserved But degraded to heat during ecosystem processes Trophic Relationships Energy and nutrients pass from primary producers (autotrophs) To primary consumers (herbivores) and then to secondary consumers (carnivores) Energy flows through an ecosystem Entering as light and exiting as heat Figure Microorganisms and other detritivores Detritus Primary producers Primary consumers Secondary consumers Tertiary consumers Heat Sun Key Chemical cycling Energy flow Nutrients cycle within an ecosystem Decomposition Decomposition Connects all trophic levels Detritivores, mainly bacteria and fungi, recycle essential chemical elements By decomposing organic material and returning elements to inorganic reservoirs Figure Concept : Physical and chemical factors limit primary production in ecosystems Primary production in an ecosystem Is the amount of light energy converted to chemical energy by autotrophs during a given time period Ecosystem Energy Budgets The extent of photosynthetic production Sets the spending limit for the energy budget of the entire ecosystem The Global Energy Budget The amount of solar radiation reaching the surface of the Earth Limits the photosynthetic output of ecosystems Only a | Chapter 54 Ecosystems Overview: Ecosystems, Energy, and Matter An ecosystem consists of all the organisms living in a community As well as all the abiotic factors with which they interact Ecosystems can range from a microcosm, such as an aquarium To a large area such as a lake or forest Figure Regardless of an ecosystem’s size Its dynamics involve two main processes: energy flow and chemical cycling Energy flows through ecosystems While matter cycles within them Concept : Ecosystem ecology emphasizes energy flow and chemical cycling Ecosystem ecologists view ecosystems As transformers of energy and processors of matter Ecosystems and Physical Laws The laws of physics and chemistry apply to ecosystems Particularly in regard to the flow of energy Energy is conserved But degraded to heat during ecosystem processes Trophic Relationships Energy and nutrients pass from primary producers (autotrophs) To primary consumers (herbivores) and then to secondary consumers (carnivores) .

• Sinh học
• Campbells Biology
• Lecture Biology
• Biological sciences
• Biological organization
• Systems biology
• Ecosystem energy budgets
• Restoration ecology
• Conservation biology
• Ecosystem dynamics
• The chemical context of life
• Water molecules
• The molecular diversity of life
• Function of macromolecules
• Membrane structure
• Metabolism transforms matter
• Cellular respiration
• Chemical energy of food
• Cell communication
• The cell cycle
• Sexual life cycles
• The gene idea
• Locating genes
• The molecular basis of inheritance
• Genetic information
• Microbial model systems
• Eukaryotic genomes
• DNA technology
• The genetic basis of development
• Darwin’s theory
• The evolution of populations
• The origin of species