The Lawson Nature Reserve (LNR) is situated within the Carolinian Life Zone, a unique ecosystem which has the warmest average annual temperatures, the longest frost-free seasons, and the mildest winters in Ontario. This area is on the northernmost edge of the deciduous forests of eastern North America. Many species of plants, trees, animals and amphibians known to this Carolinian Zone can be found at the LNR. Two distinct geographical features make up the physical characteristics of the LNR – The Ingersoll Moraine and the Salford Swamp.
The Ingersoll Moraine is made up of hilly ridges pushed ahead by glacial ice lobes. Soil debris was left behind when the glaciers receded. These ridges then eroded away. New vegetation grew on top of these ridges thereby stablizing the environment. The LNR has two ridges that cross the property.
The Salford Swamp covers 18.8 ha of land in and around the LNR. There are rare species of flora in this area. Two ponds are present on the property. The larger pond, visible from the road, dries up during the summer months. A smaller second pond is located just behind the picnic site.