High Park contains some of the most significant natural areas in the City of Toronto including:
23 vegetation communities:
136 L1 to L4 flora species
41 L1 to L4 fauna species
260 species of flora (incomplete list)
NOTE: The same area may be included in more than one category listed below.
Total park area: 161 ha
Total area designated as Environmentally Significant Area (ESA): 83.25 ha
Total area designated Area of Natural and Scientific Interest (ANSI): 73 ha
Total terrestrial areas considered "natural areas": 79 ha
Total aquatic environments: 24 ha
1 27.5 ha of black oak savannah per personal communication with Lisa McLean, Forestry, City of Toronto, May 2, 2016
Much of High Park is designated provincially significant Area of Natural and Scientific Interest (ANSI) and thus is protected for the long term by the Provincial Policy Statement and its guideline the Natural Heritage Reference Manual (NHRM). (Municipalities need to either follow the guideline or take measures that have the same effect and explain how the effect is achieved.)
The plant community in High Park is ranked G1, i.e. critically imperilled on a global basis (see G–ranks).