A research study was designed to document the types of natural communities developing in aggregate sites on the Oak Ridges Moraine and to identify the critical factors for success in their establishment.
An initial list of known pit sites were grouped into two rehabilitation categories: deliberate rehabilitation or
none; and two age categories: greater than 15 years old or less than 15 years old. Five replicate pits were
randomly chosen from each rehabilitation and age combination and these twenty pits were studied during the
1997 growing season.
Physical and biological data were collected from six hundred quadrats. Vegetation, amphibians, and birds were quantitatively inventoried and occurrences of reptiles and mammals were noted. Site and rehabilitation history and the landscape context were also determined for each pit. Study plot histories range from those which had been rehabilitated within 2 years, to those which had been abandoned for more than SO years.
Ordination of physical and site history data along with the plant species richness and density data identified key factors contributing to the establishment of different communities. A review of literature on site restoration, landscape ecology and conservation biology also contributed to identifying factors which facilitate successful site naturalisation.
This paper describes twelve factors which form the basis of a predictive model for naturalising pits on the Oak Ridges Moraine. Examples of such factors include: site size, history and topography, surface and ground water, soils, existing adjacent biological communities, social and economic factors.
Key steps for implementing pit naturalisation as a rehabilitation option are also described.