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In this module, the following topics are covered: 1) biodiversity, 2) trends in biodiversity loss with reference to species and ecosystems, 3) ways human activity affects biodiversity, and 4) biodiversity loss effects on people

Learning objectives

After reading this module, students should be able to

  • define biodiversity
  • articulate current trends in biodiversity loss with reference to species and ecosystems
  • explain some of the ways human activity affects biodiversity
  • explain how biodiversity loss concerns people

What is biodiversity?

You're probably familiar with the word, biodiversity    , whether or not you can give an exact definition of it. It's common on the signs at zoos, parks, and nature centers, and it's often used without explanation or definition. Most people understand biodiversity in general terms as the number and mix of plant and animal species that occurs in a given place. Scientists are more precise and include more in their definition. The International Union for the Conservation of Nature (IUCN) , which coordinates efforts to catalogue and preserve biodiversity worldwide, defines biodiversity as "the variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems, and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems." Rather than just species, biodiversity therefore includes variation from the level of genes and genomes to that of ecosystems to biomes.

Even within a single ecosystem, the numbers of species can be impressive. For example, there is a large region of dry forest and savanna in Brazil known as the Cerrado (see Figure Cerrado Forest ). This ecosystem alone hosts over 10,000 species of plants, almost 200 species of mammals, over 600 species of birds, and about 800 species of fish.

Cerrado Forest
Cerrado Forest . Photograph of the Cerrado Forest. Source: C2rik via Wikimedia Commons .

Generally, biodiversity is greatest in tropical areas–especially "rainforests"—but there are terrestrial biodiversity "hotspots" on all the major continents. (View an interactive map of hotspots .)

One way scientists gauge trends in biodiversity is by monitoring the fate of individual species of animals and plants. For more than 40 years, the IUCN has compiled information in the "Red List of Threatened Species," which "provides a snapshot of what is happening to species around the world." Updates to the Red List are released every four years. Here is how the authors of the most recent one, released in 2008, characterize the news it holds: "The overwhelming message" from the 2008 Red List, they write, "is that the world is losing species and that the rate of loss appears to be accelerating in many taxonomic groups" ( Vie, Hilton-Taylor,&Stuart, 2008, p. 38 ).

Summary of Threatened Species . Table lists the numbers and proportions of species assessed as threatened on the 2008 IUCN Red List by major taxonomic group. Source: IUCN Red List, Wildlife in a Changing World 2008 , p. 17. Please see IUCN Terms of Use for copyright restrictions.

Questions & Answers

how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
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Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Sustainability: a comprehensive foundation. OpenStax CNX. Nov 11, 2013 Download for free at http://legacy.cnx.org/content/col11325/1.43
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