As of 2006, conservationists have labeled polar bears a vulnerable species.

Hi,
I'm interested in your question.

My dictionaries say "as of" means "starting from a particular time

Starting from 2006 is the correct interpretation of As of 2006.

an susceptible animal won't do, however -- and neither will a susceptible animal.

Close, but no cigar!

Hmm, is that the only meaning of "as of"?
I think I often come across another meaning, which to me seems "considering the situation at that point in time...".
Some examples:

By Brian Santo, Editor - CedMagazine.com - October 01, 2007
[...] As of June, there were approximately 65.5 million cable subscribers, according to the National Cable & Telecommunications Association

Hmm, is that the only meaning of "as of"?

No, but it's the best one for the original example, I think, because of the present perfect.

With a past tense it's more likely to mean by (by the time of), or, in more words, 'considering the situation as it had already developed up to that point in time', which is essentially what you said.

Ah! Then I'm not completely nuts! Because it seems no learner's dictionary lists that meaning...

Thanks a lot.

No, not completely! (Like the rest of us!)

CJ

Thanks, kooyeen and Jim.

Got it.

AngliholicAs of 2006, conservationists have labeled polar bears a vulnerable species.

The following is how I render the above. Correct me if I am wrong. Thanks.

Starting from 2006, conservationists have labeled polar as bears an susceptible animal.

Sorry! I still have a point for you to tidy up, that is, is "as"

I assumed it was a typo for

labeled polar bears as a susceptible animal.

(The as is optional, yes.)

CJ

CalifJimI assumed it was a typo for

labeled polar bears as a susceptible animal.

(The as is optional, yes.)

CJ

Thanks, Jim.