Here is another example of a small depression that has had ice damage in previous years indicated by the predominance of bluegrass. But you can see the patches of ryegrass that have started to regain a foothold here until this winter. It's a bit early to tell if these patches will partly recover or not. I am expecting that some plants will survive and the bluegrass will expand and many of these areas will be unnoticeable in a month.
It is interesting how each species finds its' sweet spot in the differing microenvironments. On our exposed mounds bluegrass really dominates the sward as it can handle both the droughty soils and winter exposure better than ryegrass. Cart path entries and exits are dominated by ryegrass that can withstand traffic better than the blue. So there is a definite benefit to having a mix of species and varieties as each has its own strengths and weaknesses. This is the time of year when you can see the varietal differences more so as they green up quicker or slower or growth habit is more easily detected. Once they have greened up and begin growing the ryegrass and bluegrass are nearly indistinguishable resulting in a more uniform turf.
More on ice damage in this previous post: