A dataset becomes a map layer when it is included as a layer in a map (that is, represented cartographically). A dataset is any set of data (which could mean geographic or otherwise). It can be analysed, edited etc all without it ever being cartographically displayed... and so it remains a dataset and not a map layer until you pull it into your GIS GUI. So, "Ecological Integrity Dataset", sound like it is the correct term (until you display it, when you can legitimately call it a map layer - although it is STILL a dataset). By definition a map layer is geographic data. A table of non-geographic data in a map would still be a dataset, therefore, and so on. Everything else on the map is usually called map furniture.
TBH, it is splitting hairs a little in this case and many people use the terms interchangeably where GIS data is concerned. I wouldn't get too hung up on it.