comma before 'while' [conjunction]; dash to mark ellipsis

[sergtab]

Please tell me, should I use the comma before "while"?
Is it gramatically correct to omit were and insert the dash in this place? Thank you!

The most abundant trophic groups of soil fauna in the field 1 were omnivores, predators, and bacterivores, while in the field 2 - plant parasites and fungivores.

 

[Copyright]

Since you asked, here's what I would do:
The most abundant trophic groups of soil fauna in Field 1 were omnivores, predators and bacterivores; and in Field 2, plant parasites and fungivores.

• Don't substitute a dash for "were."
• I'm more comfortable with "in field 2, plant parasites" when the two major thoughts are connected by "and" rather than "while" -- which doesn't seem necessary, in any case.
• You don't have to uppercase "field" but I would do it to make it stand out for the reader.
• And I used a semicolon because of the number of commas in the sentence. If you wanted to use a dash somewhere, you could replace the semicolon with one.

 

[Apophis]

The most abundant trophic groups of soil fauna in the field 1 have been omnivores, predators and bacterivores. In the field 2, plant parasites and fungivores.

The most abundant trophic groups of soil fauna in the field 1 have been omnivores, predators and bacterivores while, in the field 2, plant parasites and fungivores.

Hi,
I'm only a student and that's how I'd say that in my native language. Some times, the sentence construction in Portuguese is very similar to English.