Microsite conditions determine differences in regeneration density of Scots pine and birch following the reduction in deer grazing pressure

In 2019, 48 plots were surveyedwithin naturally regenerating areasof Caledonian pine and upland birchwoodlands at Mar Lodge Estate, inthe eastern Cairngorms. We aimed todetermine whether there are differencesin microsite environmental conditionsand ground flora composition betweenthese areas of Pinus sylvestris and Betulaspp. regeneration, where densitiesof < 3.5 red deer per km2 have beenmaintained since 2009.Natural regeneration was found tobe greater on northeast-facing slopesand both species had established inmicrosites with similar EllenbergIndicator Values for light, nutrientavailability and acidity. Shorter heather,shallow moss/litter and bare groundenable greater P. sylvestris regenerationbut did not limit Betula regeneration.Instead greater Betula regeneration wasassociated with wetland flushes andgrasslands with less acidic, more fertileconditions.Future management for ongoing,widespread native woodlandregeneration is considered timedependent.Further managementintervention to improve micrositeconditions could be undertaken topotentially rapidly enhance regeneration.Alternatively, niche creation via heatherdegeneration would facilitate moregradual natural regeneration with thesame long-term outcome if currentherbivore control is maintained.