Understanding Ecology: Ecosystems, Biodiversity, and Energy Flow

 
Ecology Basics (Lecture 9)
 
(Photo by M. Rapien)
Developed for General Biology for non-majors, by Dr. Mary Rapien, Associate Professor of Biology, Bristol Community College
(Mary.Rapien@bristolcc.edu) .  This work is licensed under a 
Creative Commons Attribution 4.0 International License
.
 
 
Ecosystems
 
An 
ecosystem
 includes all of the plants and
animals, plus their physical surroundings (i.e.
both biotic and abiotic factors).
Each organism in a community occupies its own
niche.
Niche
:  the place occupied by a species in its
ecosystem - where it lives, what it eats, its
foraging route, the season of its activity, etc.
More abstractly, a potential role within an
ecosystem.
Definitions from E.O. Wilson, 1992
 
 
 
 
Biodiversity
 
The variety of organisms considered at all levels,
from genetic variants belonging to the same species
through arrays of species to arrays of genera, families, and still
higher taxonomic levels; includes the variety of ecosystems,
which comprise both the communities of organisms within
particular habitats and the physical conditions under which they
live
.
2 components of species diversity:
 
1) Species Richness
 
2) Relative Abundance
Approximately 1.8 million species have been described.
Scientists estimate there are between 10 and 100 million species
on Earth.
 
 
 
Energy Flow and Materials Cycling
 
We can talk about ecosystems in terms of
ENERGY FLOW and MATERIALS CYCLING
Nutrients such as nitrogen, phosphorous and
carbon cycle
Energy flows through food webs – predator/prey
relationships
 
 
The Nitrogen Cycle
 
Figure 20.12 OpenStax Concepts of Biology.  Nitrogen enters the living world from the atmosphere through
nitrogen-fixing bacteria. This nitrogen and nitrogenous waste from animals is then processed back into gaseous
nitrogen by soil bacteria, which also supply terrestrial food webs with the organic nitrogen they need. (credit:
modification of work by John M. Evans and Howard Perlman, USGS)
 
The Carbon Cycle
 
Figure 20.11 OpenStax, Concepts of Biology.  Carbon dioxide gas exists in the atmosphere and is dissolved in water.
Photosynthesis converts carbon dioxide gas to organic carbon, and respiration cycles the organic carbon back into
carbon dioxide gas. Long-term storage of organic carbon occurs when matter from living organisms is buried deep
underground and becomes fossilized. Volcanic activity and, more recently, human emissions bring this stored carbon
back into the carbon cycle. (credit: modification of work by John M. Evans and Howard Perlman, USGS)
 
Food Chains
 
Figure 20.4 OpenStax Concepts of Biology.  These
are the trophic levels of a food chain in Lake
Ontario at the United States–Canada border.
Energy and nutrients flow from photosynthetic
green algae at the base to the top of the food
chain: the Chinook salmon. (credit: modification of
work by National Oceanic and Atmospheric
Administration/NOAA)
 
Predator-prey Dynamics
 
Figure 19.13 OpenStax Concepts of Biology.  The cycling of snowshoe hare and lynx populations in
Northern Ontario is an example of predator-prey dynamics.
 
Relative Energy Content in Trophic Levels
 
Figure 20.5 OpenStax Concepts of Biology.  The relative energy in trophic levels in a Silver Springs, Florida,
ecosystem is shown. Each trophic level has less energy available, and usually, but not always, supports a smaller
mass of organisms at the next level.
 
Food Webs
 
Relationships between soil food web, plants, organic matter, and birds and mammals.
Image courtesy of USDA Natural Resources Conservation Service.
https://www.nrcs.usda.gov/wps/portal/nrcs/photogallery/soils/health/biology/gallery/?cid=1788&position=Promo
 
Keystone Species
 
A 
keystone species 
is one that has a disproportionate
effect on the ecosystem: i.e. a greater effect than its
abundance would suggest.  Often, this position is
occupied by an apex predator.
 
 
Sea Otter
    
Sea Urchin
    
Kelp
 
 
Symbiosis
 
In addition to food web relationships, organisms
can relate in other ways:
 
Symbiosis –
  
Mutualism
  
Commensalism
  
Parasitism
 
Competition
 
Competition in Paramecium spp.
 
Figure 19.19 OpenStax Concepts of Biology
 
Commensalism
 
Figure 19.20 OpenStax Concepts of Biology.  The southern masked-weaver is starting to make a nest in a tree in
Zambezi Valley, Zambia. This is an example of a commensal relationship, in which one species (the bird)
benefits, while the other (the tree) neither benefits nor is harmed. (credit: “Hanay”/Wikimedia Commons)
 
Mutualism
 
Figure 19.21 OpenStax Concepts of Biology
 
(a)
Termites form a mutualistic relationship with symbiotic protozoa in their guts, which allow both organisms
to obtain energy from the cellulose the termite consumes.
(b)
Lichen is a fungus that has symbiotic photosynthetic algae living in close association. (credit a:
modification of work by Scott Bauer, USDA; credit b: modification of work by Cory Zanker)
 
 
 
Parasitism
 
Figure 19.22 OpenStax Concepts of Biology.  This diagram shows the life cycle of the tapeworm, a human
worm parasite. (credit: modification of work by CDC)
 
Invasive Species
 
A species of plant or
animal that is expanding
its range to the detriment
of the local ecosystem.
 
 
 
 
 
Figure retrieved from Wikicommons, by user
Anonymous Powered
Asian Shore Crab
 
Funding
 
This workforce product was funded by a TAACCCT grant awarded
by the U.S. Department of Labor’s Employment and Training
Administration.  The product was created by the grantee and
does not necessarily reflect the official position of the U.S.
Department of Labor.  The U.S. Department of Labor makes no
guarantees, warranties, or assurances of any kind, express or
implied, with respect to such information, including any
information on linked sites and including, but not limited to,
accuracy of the information or its completeness, timeliness,
usefulness, adequacy, continued availability, or ownership.
 
Slide Note

Note: for all figures from OpenStax, Concepts of Biology, alt text can be found in the original text at https://cnx.org/contents/s8Hh0oOc@9.22:Pj8cW7X1@4/

Embed
Share

Explore the intricate world of ecology through topics such as ecosystems, biodiversity, energy flow, and nutrient cycling. Delve into the concept of niches, biodiversity levels, and the importance of energy flow and materials cycling in sustaining ecosystems. Learn about the nitrogen and carbon cycles, which are vital processes in maintaining the balance of elements within ecosystems.


Uploaded on Sep 02, 2024 | 1 Views


Download Presentation

Please find below an Image/Link to download the presentation.

The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.

E N D

Presentation Transcript


  1. Ecology Basics (Lecture 9) (Photo by M. Rapien) Developed for General Biology for non-majors, by Dr. Mary Rapien, Associate Professor of Biology, Bristol Community College (Mary.Rapien@bristolcc.edu) . This work is licensed under a Creative Commons Attribution 4.0 International License. Creative Commons logo Creative Commons logo

  2. Ecosystems An ecosystem includes all of the plants and animals, plus their physical surroundings (i.e. both biotic and abiotic factors). Each organism in a community occupies its own niche. Niche: the place occupied by a species in its ecosystem - where it lives, what it eats, its foraging route, the season of its activity, etc. More abstractly, a potential role within an ecosystem. Definitions from E.O. Wilson, 1992

  3. Biodiversity The variety of organisms considered at all levels, from genetic variants belonging to the same species through arrays of species to arrays of genera, families, and still higher taxonomic levels; includes the variety of ecosystems, which comprise both the communities of organisms within particular habitats and the physical conditions under which they live. 2 components of species diversity: 1) Species Richness 2) Relative Abundance Approximately 1.8 million species have been described. Scientists estimate there are between 10 and 100 million species on Earth.

  4. Energy Flow and Materials Cycling We can talk about ecosystems in terms of ENERGY FLOW and MATERIALS CYCLING Nutrients such as nitrogen, phosphorous and carbon cycle Energy flows through food webs predator/prey relationships

  5. The Nitrogen Cycle Figure 20.12 OpenStax Concepts of Biology. Nitrogen enters the living world from the atmosphere through nitrogen-fixing bacteria. This nitrogen and nitrogenous waste from animals is then processed back into gaseous nitrogen by soil bacteria, which also supply terrestrial food webs with the organic nitrogen they need. (credit: modification of work by John M. Evans and Howard Perlman, USGS)

  6. The Carbon Cycle Figure 20.11 OpenStax, Concepts of Biology. Carbon dioxide gas exists in the atmosphere and is dissolved in water. Photosynthesis converts carbon dioxide gas to organic carbon, and respiration cycles the organic carbon back into carbon dioxide gas. Long-term storage of organic carbon occurs when matter from living organisms is buried deep underground and becomes fossilized. Volcanic activity and, more recently, human emissions bring this stored carbon back into the carbon cycle. (credit: modification of work by John M. Evans and Howard Perlman, USGS)

  7. Food Chains Figure 20.4 OpenStax Concepts of Biology. These are the trophic levels of a food chain in Lake Ontario at the United States Canada border. Energy and nutrients flow from photosynthetic green algae at the base to the top of the food chain: the Chinook salmon. (credit: modification of work by National Oceanic and Atmospheric Administration/NOAA)

  8. Predator-prey Dynamics Figure 19.13 OpenStax Concepts of Biology. The cycling of snowshoe hare and lynx populations in Northern Ontario is an example of predator-prey dynamics.

  9. Relative Energy Content in Trophic Levels Figure 20.5 OpenStax Concepts of Biology. The relative energy in trophic levels in a Silver Springs, Florida, ecosystem is shown. Each trophic level has less energy available, and usually, but not always, supports a smaller mass of organisms at the next level.

  10. Food Webs Relationships between soil food web, plants, organic matter, and birds and mammals. Image courtesy of USDA Natural Resources Conservation Service. https://www.nrcs.usda.gov/wps/portal/nrcs/photogallery/soils/health/biology/gallery/?cid=1788&position=Promo

  11. Keystone Species A keystone species is one that has a disproportionate effect on the ecosystem: i.e. a greater effect than its abundance would suggest. Often, this position is occupied by an apex predator. Sea Otter Sea Urchin Kelp

  12. Symbiosis In addition to food web relationships, organisms can relate in other ways: Symbiosis Mutualism Commensalism Parasitism Competition

  13. Competition in Paramecium spp. Figure 19.19 OpenStax Concepts of Biology

  14. Commensalism Figure 19.20 OpenStax Concepts of Biology. The southern masked-weaver is starting to make a nest in a tree in Zambezi Valley, Zambia. This is an example of a commensal relationship, in which one species (the bird) benefits, while the other (the tree) neither benefits nor is harmed. (credit: Hanay /Wikimedia Commons)

  15. Mutualism Figure 19.21 OpenStax Concepts of Biology (a) Termites form a mutualistic relationship with symbiotic protozoa in their guts, which allow both organisms to obtain energy from the cellulose the termite consumes. (b) Lichen is a fungus that has symbiotic photosynthetic algae living in close association. (credit a: modification of work by Scott Bauer, USDA; credit b: modification of work by Cory Zanker)

  16. Parasitism Figure 19.22 OpenStax Concepts of Biology. This diagram shows the life cycle of the tapeworm, a human worm parasite. (credit: modification of work by CDC)

  17. Invasive Species A species of plant or animal that is expanding its range to the detriment of the local ecosystem. Figure retrieved from Wikicommons, by user Anonymous Powered Asian Shore Crab

  18. Funding This workforce product was funded by a TAACCCT grant awarded by the U.S. Department of Labor s Employment and Training Administration. The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The U.S. Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.

More Related Content

giItT1WQy@!-/#giItT1WQy@!-/#giItT1WQy@!-/#giItT1WQy@!-/#