"green vegetation crap"?? - Please refine your language. We refer to that material as "biofouling."(a term I done larned in schul) Whatever you call it, it definitely hides the good stuff.

I once took a walk with one of the park biologists. We were both on point, looking for, and commenting upon, our respective sphere of interest. It was quite interesting, because, although we were walking side by side, we might as well have been on different planets. Both of us were disregarding the trivial junk to check on important things.