Don River Watershed Plan Terrestrial Natural Heritage – Report on Current Conditions and Refinement of a Target System 2009 Prepared by: Toronto and Region Conservation Don River Watershed Plan: Terrestrial Natural Heritage – Report on Current Conditions and Refinement of a Target System Table of Contents Table of Contents............................................................................................................................ 2 List of Tables................................................................................................................................... 3 List of Figures.................................................................................................................................. 3 1.0 Introduction............................................................................................................................... 4 2.0 Terrestrial Natural Heritage in an Urban Watershed................................................................ 5 2.1 Terrestrial Natural Heritage System Strategy ....................................................................... 5 3.0 Data Sources and Methods...................................................................................................... 7 3.1 Vegetation Communities and Species of Concern .............................................................. 7 3.2 Landscape mapping ............................................................................................................. 8 3.3 Quality Distribution and Quantity of Natural Cover .............................................................. 9 4.0 Current Conditions in the Don River Watershed...................................................................... 9 4.1 Physiographic Regions......................................................................................................... 9 4.1.1 The Oak Ridges Moraine ............................................................................................. 12 4.2 Selected Policy Areas ......................................................................................................... 12 4.3 Natural Cover Landscape Analysis..................................................................................... 14 4.3.1 Quality Distribution of Natural Cover ........................................................................... 14 4.3.2 Quantity of Terrestrial Natural Cover............................................................................ 21 4.4 Vegetation Community Findings ........................................................................................ 23 4.4.1 Vegetation Communities of Concern........................................................................... 24 4.4.2 Threats to Vegetation Communities............................................................................. 26 4.5 Flora Findings ..................................................................................................................... 28 4.5.1 Flora Species of Concern............................................................................................. 28 4.5.2 Threats to Flora Species .............................................................................................. 32 4.6 Fauna Findings ................................................................................................................... 35 4.6.1 Fauna Species of Concern........................................................................................... 36 4.6.2 Threats to Fauna Species ............................................................................................ 40 4.7 Summary of Current Conditions and Ratings for the Natural Heritage Indicators ............ 42 5.0 Regenerating the Don............................................................................................................. 45 5.1 Refinement of the Target System for the Don River Watershed ........................................ 45 5.2 Management Considerations ............................................................................................. 48 5.2.1 Implementing the Terrestrial Natural Heritage System Strategy................................. 48 5.2.2 Mitigate the Matrix Influence ........................................................................................ 49 5.2.3 Urban canopy............................................................................................................... 50 5.2.4 Regeneration of Mature and Old-growth Forests........................................................ 52 5.2.5 Take a Long-term Approach ........................................................................................ 52 5.2.6 Special Wetland Considerations.................................................................................. 52 5.2.7 Opportunities outside the Target System.................................................................... 53 5.2.8 Opportunities for Native Terrestrial Species within the Don River Watershed............ 54 6.0 References .............................................................................................................................. 56 Appendix A: Summary of the habitat type and land use patch definitions used in landscape analysis. ........................................................................................................................................ 59 Toronto Region Conservation CFN: 37590 2 2009 Don River Watershed Plan: Terrestrial Natural Heritage – Report on Current Conditions and Refinement of a Target System Appendix B: List of vegetation communities mapped in the Don River watershed 1996-2005.. 60 Appendix C: List of flora species found in the Don River watershed from 1996-2005................ 68 Appendix D: List of fauna species found in the Don River watershed. ....................................... 89 List of Tables Table 1: Terrestrial natural heritage data sources and years collected. ....................................... 8 Table 2: Existing conditions (2002) for terrestrial natural heritage by subwatershed based on 2002 remote sensing and LAM. ............................................................................................ 14 Table 3: Severe disturbances in natural areas based on data collected for ELC polygons (2000- 2005 data).............................................................................................................................. 19 Table 4: Woodlands, wetlands and meadows by subwatershed in the Don River watershed... 21 Table 5: Objectives, indicators, measures, and targets for terrestrial natural heritage in the Don River watershed..................................................................................................................... 44 Table 6: Refined target terrestrial natural heritage system by subwatershed............................. 48 List of Figures Figure 1: Natural cover and urbanization across TRCA's jurisdiction. .......................................... 6 Figure 2: Natural habitat types in the Don River watershed (based on 2002 aerial photo interpretation). ....................................................................................................................... 10 Figure 3: Physiographic regions in the Don River watershed. .................................................... 11 Figure 4: Policy areas in the Don River watershed...................................................................... 13 Figure 5: Existing natural habitat quality in the Don River watershed (2002 conditions). .......... 15 Figure 6: Forest interior in the Don River watershed. .................................................................. 17 Figure 7: Surveyed vegetation communities severely disturbed by trampling, trash, or non- native species (2000-2005 data). .......................................................................................... 20 Figure 8: Flora species of concern in the Don River watershed.................................................. 30 Figure 9: Fauna species of concern in the Don River watershed................................................ 37 Figure 10: Refined target terrestrial natural heritage system for the Don River watershed. ....... 47 Toronto Region Conservation CFN: 37590 3 2009 Don River Watershed Plan: Terrestrial Natural Heritage – Report on Current Conditions and Refinement of a Target System 1.0 Introduction The Toronto and Region Conservation Authority (TRCA), in consultation with the multi- stakeholder Don Watershed Regeneration Council and watershed municipalities, is developing a watershed plan for the Don River. This watershed planning process has been initiated in response to a number of recent policy and planning developments, including the need to fulfill York Region’s watershed planning requirements under the Oak Ridges Moraine Conservation Plan (ORMCP, Ontario Regulation 140/02) and to update the original management strategy outlined in Forty Steps to a New Don (Metropolitan Toronto and Region Conservation Authority [MTRCA], 1994). The goal of the watershed planning study is to recommend updated management strategies that will guide land and water use decisions, such that the overall ecological health of the Don River watershed is protected and improved. The aim is to build on the Forty Steps’ principles to protect what is healthy, regenerate what is degraded, and take responsibility for the Don. Recognizing the significant watershed planning work that has already been completed,