From this thread:
In terms of sheer biomass and resources consumed, what is the most predominant lifeform? Alge? Some bacterium? Clostridium botulinum?
Viruses and prions need not apply. (And we’ll just dispense with the obligatory lawyer joke, 'kay? 
)
Stranger
I don’t have any answers, just wanted to ask for a clarification… how do we define ‘life form’.
Are you asking for the species with the greatest biomass on the earth and/or that ingests the greatest total mass on a daily basis??
I’m not sure, but I think leading condenders would be ocean algae and possibly even…
grass?? 
I’ve heard that ants make up 10% of the Earth’s biomass, and termites make up another 10%. Depending on how narrowly or broadly you define “lifeform,” I’d think that these would be contenders.
Let’s define lifeform as prokaryotic bacteria and above.
Either/or. I’m just curious about the real contenders for the title of “Dominant Form Of Life On Planet Earth”, as opposed to “Those Uptight Pink Monkeys Who Walk Upright But Can’t Talk About The Basic Steps Of Sexual Reproduction”.
Yeah, that’s an evolutionarially valuable trait. :rolleyes:
Stranger
I wasn’t actually asking how to recognize an organism as a lifeform so much as how to determine if two different organisms count as the same lifeform. For instance… zut mentioned ants. Do we group all ants into the same category or seperate ‘black ant’ from ‘red robber ant’??
(I doubt that 10% figure since all the cite seems to give as backing evidence is ‘Some scientist said…’)
I think data on this question will not be easy to find. 
Oh, let’s limit the distinction to the genus or at most, family, level. So, all ants would be lumped together and so forth.
Just swag a miss at it; don’t worry about being too pedantic.
Stranger
No cite, but I remember reading (probably in a Stephen Jay Gould book) that the total biomass of bacteria exceeds that of all the other forms of life combined.
You asked “most biomass/resources consumed” and that’s a little difficult to answer. But when questions like this come up, I like to wheel out a surprising piece of trivia learned from my college Invertebrate Zoology professor. The most numerous animal group in the world is thought to be copepods, a kind of tiny crustacean zooplankton. (Note that this restricts the discussion to animals and the numbers thereof, and doesn’t exactly satisfy your OP. But I thought you might find it interesting).
A previous thread
I’m not sure who that is thought by. The phylum nematoda is found free-living in all marine and terrestrial environments as well as parasitic in every macroscopic organism. The simple fact that almost every individual copepod will have an individual nematode parasite and there are still billions more living free and infecting other species makes the claim impossible.
I think the problems with these claims is that they are very loose with the useof the term group. Nematodes are group, they are a phylum, while copepods are simply a class within a phylum.
This cannot be true, as “biomass” would include all algae, bacteria, fungi, plants, zooplankton, all other invertebrates, etc. I highly doubt even all the Hymenoptera (termites, ants, bees, and wasps) combined would account for 10% of earth’s biomass.
I would not be surprised to learn that the most numerous, and overall “dominant” living thing in terms of biomass is chemosynthetic bacteria living in soil and the Earths crust.
It’s completely irrelevant to your point, but termites are not Hymenoptera, despite being eusocial (interestingly, they’re not haplodiploid either).
Beetles???
I always thought the dominant form of life on Earth was stupidity.
Or is that the “most powerful force in the universe”?