GWD-31-Q30-Q33 这句话怎么翻译？？？

allen0018

    

        

It might seem that certain traits
would clearly define a species as a keystone species;
for example, Pisaster ochraceus is
often a keystone predator because it consumes and suppresses mussel
populations, which in the absence of this starfish can be a dominant
species. 

    

下面这句怎么翻译？？？

But
such predation on a dominant or potentially dominant species occurs in systems
that do as well as in systems that do not have species that play keystone roles？？？？？？？？？？？？？？.

谢谢