Many of the best winter climbing venues are sheltered or north-facing cliffs which hold considerable amounts of vegetation. Some are locations of rare alpine plants. It is important that vegetation and turf is completely frozen to minimise damage to the plants.
Ensure the cliff has a 'winter' appearance with snow, ice or verglas completely covering rock, not just snow on the ledges.
Winter ascents of summer rock routes with crampons, peg placements and axes in cracks can cause damage, like chipping the rock, and potentially ruining the summer rock route.
Skiing on incomplete snow cover can have the effect of skis slicing through the vegetation and compacting remnants of snow can further damage it.
So, only ski when you are sure conditions are generally good and keep to stretches of complete snow cover.
Be aware of how you move through the managed ski resorts; always follow the Snowports Touring Code.
Popular sites can suffer from litter and human waste appearing when the snow thaws. You should be prepared to carry everything out that you carry in.