I don't see a resume attachment, is there one? Check out a website called jobscan.co for some help tailoring your keywords. It allows you to 'test' your resume as if it were going through an automated resume scanner. My husband used it in his search this summer with great results, and you get 5 free runs a month.
I also learned a lot this year about the new world of resumes, which is definitely contradicting everything I learned 10 years ago in college. With private sector and local govt jobs there is a strong possibility your application and resume will be scanned by an ATS. Google terms like resume advice ats, or getting past automated tracking systems, new resume rules, etc. A lot of old advice like 1 page max is no longer true in many fields including yours. If you have a lot of good experience, you may need 2 pages. What you can't do is have fancy layouts, crazy formatting, exotic fonts, columns or tables... The resume scanning software can't read it and will discard your application. You need standard web-safe fonts, all left justification, etc. Apparently even something so innocent as a horizontal line separating sections can throw it off. And no tiny little font to make it 1 page, PDF isn't necessarily best, clear format with job, title, years, all easy to find; read up on it. Also google docs format might be risky, if you don't have access to word consider making it as simple as possible or even a .txt version or something. It is insane how much has changed.
As for what to include, I would say be precise but brief with training and certification. They won't care about your irrelevant experience if you clearly have plenty of relevant stuff on there. I am in ecology/conservation field too and I think managing volunteers in your field trumps food service by far if you run out of room.
Good luck!!