Dwarf hackberry (Celtis tenuifolia) COSEWIC assessment and status report: chapter 8

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Limiting Factors and Threats

Twig-boring insects were found to be associated with a significant level of mortality (10% per year) at Point Pelee (Dunster, 1992). There were no observations of significant mortality in 2002; the bark beetle may be of local and cyclical occurrence. Shade, due to successional forest development, is a potential limiting factor; however, these populations occur on droughty sites (sand spits, dunes and alvars) and with the recent summer droughts they have survived well, as other forest species that could cause shading have been held in check. In 2002, no evidence of decline of individuals due to shade was observed. In eastern Ontario, there is the threat due to habitat being lost to quarry operations; at Stirling Slope, the expansion of the adjacent sand pit is a threat. The intensification of cottage development on Pelee Island is another potential threat.