I will have to get the Sector Construction Guide and check out that table set.There's a biocomplexity rating, from simple single celled organisms (like prokaryotes) to "Ecosystem-wide superorganisms" but other than some generic earthlike examples, no particular details.
It's probably worth a whole book to do ecosystems right - flora, fauna, things in-between or neither, with some rules on design based on environment - not another 'Animal Encounters' (Classic Supplement 2 and MgT v1 Supplement 11), but something to build a native ecosystem. And perhaps deal with mixed ecosystems - in The Third Imperium, there's 300K years of Ancients interference and consequences, 10K years of Vilani imported invasive species, and 3K years of Solomani imports and geneering. And then a bunch of tables for those who just want something quick and easy.
Existing, but hardly sufficient is a table I put in the Sector Construction Guide dealing with sophont physical characteristics (p.51 if you have it). That table is more 'prompts' to to stimulate Referee imagination than any sort of design system.
I think even having a similar prompt table repeated in this book would be useful if to stimulate the imagination to do things like
"Welcome to planet 123-789, one of the major organisms on this primarily water planet is an amphibious squid like creature call.... It isn't that dangerous to visitors and colonists. While the rest of the planet is covered in swamp like brush...."