The Acadian Forest Region of eastern Canada has experienced a pronounced shift in age structure and successional patterns as a result of human disturbance during the last 400 years. Since European settlement, Nova Scotia has experienced land clearing for the purposes of agriculture, shipbuilding, town and road construction, mining as well as small scale and industrial forestry.

The pre-European condition of the Acadian forest was one of uneven aged climax forest under a predominantly gap-disturbed regime. Typically, lands cleared for agriculture were often composed of the climatic climax forest type for the region, which consists of tolerant broadleaf (hardwood) and coniferous (softwoods) species in separate distinct communities, as well as in mixed stands. Tolerant hardwood species include sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britt.) and American beech (Fagus grandifolia Ehrh.). Tolerant softwood species include white pine (Pinus strobus L.), red spruce (Picea rubens Sarg.) and eastern hemlock (Tsuga canadensis (L.) Carrière). Following the first major settlement in the early 1600’s by French colonialists, the forests of Nova Scotia have been under steadily increasing management for forest products, as well as gradual conversion of forested land to serve agricultural purposes. Both of these types of activities represent types of disturbance unprecedented in post-glacial Nova Scotia. Over large tracts of land, the characteristic gap disturbance regime was, and continues to be, overridden by human activities such as agriculture and large scale forestry.

Divergence from a gap disturbance regime in the initial stages of agricultural development have led to dramatic structural and ecological divergence from the relatively stable state that existed in this previously forested land. Activities such as land clearing, stumping and burning of woody debris, plowing, leveling, removal of stones and boulders, grazing, cropping and alteration or redirection of natural drainages all play a role in this divergence.

Based upon Nova Scotia’s Ecological Land Classification (ELC), up to 58% of the land base of Nova Scotia has potential to sustain climax forests consisting of Acadian species. Included in this 58% of the land base are lands currently in a post-agricultural forest condition. B.E. Fernow indicated that in 1909-1910, Nova Scotia contained 918,759 ha designated as agricultural land. As of 2001, 407,046 ha were in agricultural production province wide. Clearly, much of the balance of this discrepancy currently exists in various stages of regenerating forest land, as well as recent cutovers and planted cutovers. The question remains as to the timeframe and pathways by which these lands succeed to a climax forest.

While post-disturbance changes in soil properties may be minimal at the landscape (or ecosection) level, site level variations in microtopography, mineral soil exposure and light environment may be creating unique opportunities for vegetative establishment. These variations shall be considered as defining characteristics in my definition of microsite in this study. In a steady state gap disturbed system such as a climax forest, typically both seed supply and microsite requirements are present. Disturbance events always assure the presence of microsites, as well as an ever present supply of propagules ready to establish within them. In larger scale disturbance, both of these factors are diminished. In the case of agricultural fields for example, the deliberate removal of microsite features as well as propagule sources is inherent. Clearly, this type of landscape faces obstacles in the regeneration of the type of climax forest which is potential for any given ELC unit. This becomes particularly apparent in the context of natural regeneration on old-field sites, which is unpredictable at best.

This study endeavors to obtain additional knowledge on the post-white spruce successional ecology of old-field sites, and potentially provide a foundation for best management practices in restoration ecology for the Acadian Forest Region.