Middlesex Natural Heritage Systems Study (2014)

The 2014 Middlesex Natural Heritage Systems Study (MNHSS) is an update to the 2003 Middlesex Natural Heritage Study. The 2003 study was one of the first natural heritage studies completed in Ontario that used landscape-level ecological parameters and a set of criteria to determine significant natural heritage features at the county level.

The County of Middlesex recognized that an update would be beneficial to make use of more recent, better quality aerial photography and to have regard for the changing natural heritage science including the updated Provincial Natural Heritage Reference Manual and natural heritage studies completed for Oxford and Huron counties. Also, land use planning has moved towards a ‘systems approach’ to natural heritage planning where the connections between patches are considered in addition to the content of individual patches.

The five Middlesex conservation authorities (ABCA, SCRCA, LTVCA, KCCA, UTRA), with the UTRCA as the lead, completed the MNHSS on behalf of the County. The process was overseen by a Steering Committee and assisted by a Technical Advisory Committee with expertise in ecology, biology, mapping and planning.

The process included detailed and comprehensive mapping using Geographic Information Systems (GIS) based on current (2010) aerial photography. This mapping was undertaken at the Vegetation Community level, being the smallest mapped natural heritage feature at 0.5 ha in area. Then, the 18 Vegetation Community types were lumped into eight Vegetation Groups. Finally, the Vegetation Groups were assembled into three Vegetation Ecosystems.

A list of 15 significance criteria was developed that defines what specific features, functions, sizes, habitats, etc. are important. These criteria were mapped separately and then a summary map was produced. The Study included a peer review component whereby information was taken to an outside consultant to review and provide input at two stages of the process before the document was finalized.

The MNHSS concluded that 20.1% of the County (including City of London and First Nation Reserves) is in natural vegetation cover and that 98% of this natural cover (by land area) meets one or more criteria, resulting in 19.7% of the County being significant natural heritage. Woodlands are by far the largest component but there are also significant amounts of meadow, especially along major watercourses.

The report was endorsed by County Council.

Report

• Executive Summary, Chapters 1-2
• Chapters 3-5
• Appendices

Maps

The links below are for high resolution versions of the maps within the report.

• Figure 14. Patches that meet one or more criterion in geographic Middlesex
• Figure 15. Patches that meet one or more criterion in Middlesex Centre
• Figure 16. Patches that meet one or more criterion in Thames Centre
• Figure 17. Patches that meet one or more criterion in Strathroy Caradoc
• Figure 18. Patches that meet one or more criterion in North Middlesex
• Figure 19. Patches that meet one or more criterion in Lucan Biddulph
• Figure 20. Patches that meet one or more criterion in City of London
• Figure 21. Patches that meet one or more criterion in Southwest Middlesex
• Figure 22. Patches that meet one or more criterion in Newbury

• Appendix I-1. Criterion 1 Map, Significant Valley Systems
• Appendix I-2. Criterion 2 Map, Areas of Natural and Scientific Interest
• Appendix I-3. Criterion 3 Map, Group within 30 m Watercourse
• Appendix I-4. Criterion 4 Map, Wetlands
• Appendix I-5. Criterion 5 Map, Woodlands Size ≥ 4 ha
• Appendix I-6. Criterion 6 Map, Woodland Proximity
• Appendix I-7. Criterion 7 Map, Thicket Size ≥ 2 ha
• Appendix I-8. Criterion 8 Map, Meadow Size ≥ 10 ha
• Appendix I-9. Criterion 9 Map, Meadow Proximity
• Appendix I-10. Criterion 10 Map, Patches that meet a Group Criteria
• Appendix I-11. Criterion 11 Map, Diversity
• Appendix I-12. Criterion 12 Map, Proximity
• Appendix J-1. Map showing patches ≥ 100 ha
• Appendix J-2. Map showing patches that contain Woodland Interior