A commentator on my blog brought up this nice idea of how to use the GScholarScraper function for bibliometrics..
I altered the code a little bit which enables to set a year since when results should be returned and added a field to the output collecting the year of publication. With this you can simply do something like this:
input <- "intitle:metapopulation"
df <- GScholar_Scraper(input, since = 1980, citation = 1)
hist(df$YEAR, xlab = "Year",
main = "Frequency of Publications with\n\"METAPOPULATION\" in Title")