A&O SCI 1 Lecture 16: A&O SCI 1: Lecture Titled "Impacts on Terrestrial Ecosystems"
Impacts on Terrestrial Ecosystems
An ecosystem is a community of living organisms that interact with one another and with abiotic
components in their environment (sunlight, air, water, minerals)
• System by which energy and nutrients flow and are recycled among the living and nonliving
components
• Each specials fulfills one of three roles:
o Producer
o Consumer
o Decomposer
• Think pyramid of food chain!
Food web which shows the interrelationships among species
• Highly dependent on one another for survival
• What would happen if we lost or gained species???!!
Stability
• Ecosystems sustain themselves when species are playing their roles:
o Producers convert energy and nutrients into food
o Consumers eat this food, themselves becoming food for consumers higher up the food
chain; keep populations of species they consume in check
o Decomposers return nutrients to a form that can be taken up by producers 7 the cycle
begins anew
• Ecosystem with higher biological diversity ("biodiversity") are more resilient
o Multiple species play a role and can pick up slack of others if necessary
o Less diverse ecosystems are sensitive to disruption
• Evolve around a particular set of physical circumstances, such as availability of sunlight, water,
and range of temperature
o Abrupt changes to these circumstances can disrupt the ecosystems that have adapted to
them
Climate and Terrestrial Ecosystems
• Temp and precipitation are climatic factors that shape terrestrial ecosystems
• Major biomes are distributed across the globe based on temp and precipitation!!
Effects of climate change --
• Rising temperatures
• Changes in seasons
• Acceleration of hydrologic cycle
• Increased frequency and magnitude of extreme events
These can lead to…
• Shifts in ecosystem types
• Migration of species
• Changes in species interactions and food webs
• Spread of diseases
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Document Summary
An ecosystem is a community of living organisms that interact with one another and with abiotic components in their environment (sunlight, air, water, minerals) System by which energy and nutrients flow and are recycled among the living and nonliving components: each specials fulfills one of three roles, producer, consumer, decomposer, think pyramid of food chain! Food web which shows the interrelationships among species: highly dependent on one another for survival, what would happen if we lost or gained species???! Climate and terrestrial ecosystems: temp and precipitation are climatic factors that shape terrestrial ecosystems, major biomes are distributed across the globe based on temp and precipitation! Effects of climate change -: rising temperatures, changes in seasons, acceleration of hydrologic cycle. Shifts in ecosystem types: migration of species, changes in species interactions and food webs. In mountain landscapes, temp decreases w increasing alt --> warming lead to upward shift. Species suited to coldest environments could lose their habitat.