Ever heard of a little thing called contraception? Considered the possibility that it could have an effect on the birth rate. Homosexuals are a minority. A reaosnably sized one, but there would have to be a good few more of them to cause a declining population by themselves.
EDIT - In regard to those articles, no one has claimed that we are not facing a declining population in Europe. You have failed to provide any evidence that it has anything to do with people being gay.
And you've just posted the same set of links twice. As a reply to a post that asked about something completely different. You're going to have to get your act together if you want to be taken seriously.
Do visitors of this country (asylum seekers, people on holiday, immigrants etc) have to be testred for STIs? j/w