Energy Transfer & Nutrient Cycling

How is energy transferred in an ecosystem? Organisms in a community survive by either producing or consuming food

How is energy transferred in an ecosystem? Trophic levels - levels of feeding in a community

How is energy transferred in an ecosystem? Producers - produce food for themselves (ex. plants), Other organisms may eat producers.

How is energy transferred in an ecosystem? Consumers - must take in food (ex. fungi) Primary Consumers - also called herbivores (ex. cow)

Energy Flow Consumers- organism that relies on other organisms for its energy and food supply (Heterotrophs) Herbivores- eat only plants Carnivores- eat animals Omnivores- eat both plants and animals Detritivores- feed on plant and animal remains and other dead matter (mites, earthworms) Decomposers- breaks down organic matter (bacteria and fungi)

What is it?

What is it?

What is it?

What is it?

What is it?

How is energy transferred in an ecosystem? Secondary and Tertiary Consumers - may be carnivores (ex. lion) or omnivores (ex. bear)

How is energy transferred in an ecosystem? Decomposers - as they consume, they break down wastes and dead organisms and return nutrients to the soil.

Food Webs Made up of overlapping food chains.

Food Webs Shows feeding connections; arrows illustrate energy transfer Ex:

Food Web A network of complex interactions that links all the food chains in an ecosystem together

Fill It In … Answer using the food web: Organisms that eat grass. Food sources for the fox. An “omnivore”. An “herbivore”. A “carnivore”.

Ecological Efficiency Producers have the most available energy (sun). Energy is lost as it moves up through the food web; 10% rule - only 10% of the available energy is passed to the next trophic level.

Biomass Pyramid Biomass- the total amount of living tissue within a given trophic level Pyramid represents the amount of potential food available at each trophic level

Pyramid of Numbers B. Energy is lost from level to level as: 1. Heat (due to cellular respiration conversions) 2. Unused material 3. Waste Based on the number of organisms at each level Could this pyramid look any differently?

Ecological Efficiency The “lost” energy is used to catch, eat, and digest food

Fill It In … 10% Rule: Carnivores (_____ cal) Herbivores (_____ cal) Plants (1000 cal)

Bioaccumulation in NC Bioaccumulation: the build up in higher trophic levels of certain chemicals like mercury and pesticides. Almost all samples of fish taken from NC rivers contain some level of mercury. Large mouth bass has been placed on a consumption advisory.

Check Yourself! What is a trophic level? What is the difference between an omnivore and a carnivore? From the food web above, write out a food chain that includes the rat. Which level in a food web has the most energy?

Check Yourself! What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY What is the difference between an omnivore and a carnivore? From the food web above, write out a food chain that includes the rat. Which level in a food web has the most energy?

Check Yourself! What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT From the food web above, write out a food chain that includes the rat. Which level in a food web has the most energy?

Check Yourself! What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT From the food web above, write out a food chain that includes the rat. (ANSWERS WILL VARY) Which level in a food web has the most energy?

Check Yourself! What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT From the food web above, write out a food chain that includes the rat. (ANSWERS WILL VARY) Which level in a food web has the most energy? PRODUCER

How is matter reused in an ecosystem? Role of decomposers Decomposers break down wastes and dead organisms Decomposition allows nutrients to be returned to the soil and atmosphere; this allows nutrients to be reused. Decomposers include fungi, bacteria, and invertebrates

How is matter reused in an ecosystem? Biogeochemical Cycles - the pathway through which a substance is recycled Water cycle Enters ecosystem by precipitation; may infiltrate the soil (be absorbed) or run-off into surface water

How is matter reused in an ecosystem? Water cycle Returned to atmosphere by evaporation or transpiration (the loss of water by plants)

Fill It In … Diagram of water cycle:

How is matter reused in an ecosystem? Carbon cycle Powered by two main processes Photosynthesis - plants and algae capture CO2 from the air and change it into sugar (which have carbon)

How is matter reused in an ecosystem? Carbon cycle Respiration - all living things break down sugars for energy, which returns CO2 to the atmosphere

How is matter reused in an ecosystem? Carbon cycle Other factors in the carbon cycle: Decomposition returns carbon to the soil and atmosphere

How is matter reused in an ecosystem? Carbon cycle Humans burn fossil fuels which adds CO2 to the atmosphere Deforestation removes tress which normally photosynthesis and remove CO2 from the atmosphere

How is matter reused in an ecosystem?

CARBON CYC LE

Fill It In … Factors that ADD carbon to atmosphere: Factors that REMOVE carbon from atmosphere:

Using the Carbon Cycle diagram on page 77 of textbook: What are the 4 sources/processes that ADD carbon to the atmosphere? What are the 2 sources/processes that REMOVE carbon from the atmosphere? What process do animals carry out that adds CO2 to the atmosphere? What process do plants carry out that removes CO2 from the atmosphere? The combustion of _______ by humans can add CO2 to the atmosphere. ______ of dead organisms may return carbon to the soil. How is carbon stored in plants transferred to animals?

How is matter reused in an ecosystem? Nitrogen Cycle Nitrogen is essential for living organisms so that they can build proteins; nitrogen is plentiful in the atmosphere, but is not usable in this form.

How is matter reused in an ecosystem? Nitrogen Cycle Nitrogen fixation - bacteria living in the root nodules of bean plants (legumes) convert nitrogen from the air into a more usable form.

How is matter reused in an ecosystem? Nitrogen Cycle Nitrogen fixation is the first of many steps that involves bacteria and changing the form of nitrogen.

Nitrogen Cycle Questions What are the main nitrogen containing nutrients in the biosphere? ammonia, nitrate, nitrite What controls the primary productivity of an ecosystem? the amount of available nutrients What is a limiting nutrient? a single nutrient that is scarce or cycles very slowly Why do algal blooms occur? when more nutrients are available and producers can produce more than consumers can eat What does “equilibrium” of an ecosystem mean? equilibrium = balance

Check Yourself! How do decomposers help with the recycling of nutrients? How do plants return water to the atmosphere? What two processes drive the carbon cycle? What organisms are essential for the conversion of nitrogen?

Check Yourself! How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE How do plants return water to the atmosphere? What two processes drive the carbon cycle? What organisms are essential for the conversion of nitrogen?

Check Yourself! How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE How do plants return water to the atmosphere? TRANSPIRATION What two processes drive the carbon cycle? What organisms are essential for the conversion of nitrogen?

Check Yourself! How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE How do plants return water to the atmosphere? TRANSPIRATION What two processes drive the carbon cycle? PHOTOSYNTHESIS & RESPIRATION What organisms are essential for the conversion of nitrogen?

Check Yourself! How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE How do plants return water to the atmosphere? TRANSPIRATION What two processes drive the carbon cycle? PHOTOSYNTHESIS & RESPIRATION What organisms are essential for the conversion of nitrogen? BACTERIA