This post is something I just was wondering about. It's not a problem I am facing but I was thinking about it and I simply don't know the answer. What would happen to a web site in the search engine rankings if a high page rank web site suddenly lost most of its links? Obviously this is not likely to happen, but it is more of a hypothetical that I was pondering. Would the web site maintain decent pagerank and rankings in the search engines? Would it plummet or trickle down over time? I simply don't know...
could be.. only google know the exact answer.. so i suggest to continue building more links to avoid it.
It will decrease in PR in the next PR update. PR is based on the quality of the inbound links in respect to how many outbound links on that incoming site. If you lose that backlink from that PR5 site then you lose a portion of your final PR.
It could affect that site but it depends on how the site established like being a much authority site, no direct big effect will happen to it...