dmcser-ga,
Thanks for an interesting question.
We humans like to think of ourselves as the powers-that-be on planet
Earth, and perhpas we're justified in that.
But in terms of biomass, we're just small potatoes. In fact, although
potatoes don't necessarily outweigh us, the total mass of agricultural
crops amounts to about 9-10 times more weight than the biomass of
humans.
There is twice the biomass of krill as that of humans. Bacteria in
the ocean -- at least 150 times the biomass of we mere human beings.
Overall the combined weight of biological material -- animals, plants,
insects, crops, bacteria, and so on -- has been estimated in one
source at about 75 billion tons. Of this:
--humans comprise about 250 million tons (0.33%)
--krill, about 500 million tons (0.67%)
--farm animals, 700 million tons (almost 1%)
--crops, 2 billion tons (2.7%)
Although these numbers are intriguing, they should be taken with a
very large grain of salt. Although there is a pretty good inventory
of the world's number of people and crops -- hence reasonable
estimates of their total biomass -- this is not the case with most
other biological materials. Hence, the numbers are only educated
guesses (and in some cases, not-so-educated guesses).
Other problems arise with the way people 'measure' biomass -- sometime
total organism weight is used, sometimes only dry weight, which
ignores the part of the organism made up of water. As you can
imagine, that would make for some wildly divergent numbers.
Smaller problems arise with imprecise use of units -- sites are not
always clear when they are using English 'tons' or metric 'tonnes',
although the difference between the two can reasonably be ignored for
such large, imprecise numbers anyway.
In fact, at least one site quotes a total biomass far higher than the
number I used above:
http://www.regensw.co.uk/technology/biomass-faq.asp
Q. How much biomass exists?
A. Worldwide, total biomass is a huge resource estimated as 1,250
billion tonnes of dry plant matter...
Another source puts the amount of oceanic cyanobacteria at 44 billion
tons, a huge chunk of the earth's total living matter.
The best single 'big picture' overview of the world's biomass that I
found comes from Wikipedia:
http://en.wikipedia.org/wiki/Biomass
Some other tidbits from around the web:
http://www.perceptions.couk.com/superants.html
Scientists say that about 15 percent of the Earth's total biomass _
the combined weight of all living things _ is composed of ants.
Another 17 percent is taken up by termites
http://www.uwyo.edu/AgCollege/Strategic_Issues_files/Microbiology_plan.htm
Microbes...include the bacteria, archaea, fungi, protozoan and
metazoan parasites, algae, and sub-cellular entities like viruses,
viroids, and prions...are estimated to comprise over 50% of the total
biomass on planet earth.
http://www.biologie.uni-hamburg.de/b-online/e54/54c.htm
More than 90 percent of the total biomass of the earth is made up by plants
http://www.delta-green.com/comint/dgml/v04/04-113.txt
Even quite conservative estimates suggest that the inclusion of all the
microbes that are likely to be present beneath seafloor hydrothermal systems
could double estimates of the total biomass on Earth
http://www.astrobio.net/news/article307.html
Dive deep beneath the sea; dig even deeper, hundreds of meters below
the sea floor, and you'll find a hidden world of microscopic beings so
numerous that they may make up a third of Earth's total biomass - as
many as a billion cells per cubic centimeter of sediment.
http://www.szgdocent.org/resource/ff/f-rain1.htm
Rainforests account for half the world's total biomass!
The takeaway message here is that there's a huge tonnage of plants,
bacteria, ants, termites and krill on this planet, and a piddling
weight of human beings (though I'm the first to admit I could stand to
lose a few pounds!).
I trust this information fully answers your question.
However, please don't rate this answer until you have everything you
need. If there's anything more I can do for you, just post a Request
for Clarification, and I'm happy to assist you further.
pafalafa-ga
search strategy -- Google searches on:
"world's OR earth's OR planet's total biomass"
"total biomass * earth"
"total biomass" insects billion
"total biomass" insects
"total biomass" "1..1000 billion tons OR tonnes"
"world's OR earth's OR planet's total biomass" |
