Deerberry Recovery Strategy Executive Summary
This document provides a summary of the recovery strategy for the deerberry, which advises the ministry on ways to ensure healthy numbers of the species return to Ontario.
Prepared by the National Deerberry Recovery Team
Deerberry (Vaccinium stamineum) is a short, colonial shrub in the Heath family, in the genus Vaccinium which includes blueberries and cranberries. Deerberry is designated as threatened by both the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and by the Committee on the Status of Species at Risk in Ontario (COSSARO). Deerberry is listed as threatened under Schedule 1 of the federal Species at Risk Act (SARA) and under the Species at Risk in Ontario List (Ontario Reg. 230/08).
Less that one percent of the global range of Deerberry occurs in Canada, where it is located in only two areas, both in Ontario: the Niagara region and the Thousand Islands region. There are a total of six sites with extant populations in Ontario, one in the Niagara region and five in the Thousand Islands region. At least six additional populations in the Niagara region have been extirpated in the last 70 years. The overall population in the Thousand Islands region has been fairly stable for the last 40 years. The extant Niagara population consists of only three colonies with a total of nine stems and is protected by the Niagara Parks Commission. The population in the Thousand Islands region is larger. There, St. Lawrence Islands National Park protects four of the five sites. Two of these sites contain populations that originated from introductions. One site in the Thousand Islands region is located on private property.
Deerberry occurs in open oak woodland in the Niagara region and in woodland containing Red Oak (Quercus rubra), Pitch Pine (Pinus rigida), and White Pine (Pinus strobus) in the Thousand Islands region. These vegetation types are usually considered to be associated with past fires and are seral communities (intermediate successional stages).
Several inherent characteristics may be limiting factors for Deerberry at its northernmost range limit. These include low reproductive success, lack of winter hardiness, low genetic diversity, a possible lack of seed or pollen vectors, and competition from other plant species such as blueberries. The lack of reproductive success is the most serious challenge for Deerberry recovery. No natural seedling establishment has been observed in Ontario to date although plants set fertile fruit.
Threats to Deerberry include a lack of available habitat due to natural succession or fire suppression, trampling, and erosion or soil slumping. In some areas deer browsing may be a significant threat. Several factors not currently thought to seriously affect populations may actually be or become potential threats, including invasive species, urbanization, and disease pathogens.
Many recovery actions have already been completed or are underway, most notably reintroductions at St. Lawrence Islands National Park, research on germination and genetics, and spraying to eliminate European Buckthorn (Rhamnus cathartica) at the Niagara site.
Knowledge gaps that must be filled in order to make recovery efforts more effective include determining the cause of Deerberry’s low reproductive success, the habitat requirements of the species, the role of fire in habitat creation and maintenance, the genetic variability of local populations, the environmental conditions necessary for seedling establishment, and the life history of Deerberry such as knowledge of vectors, mycorrhizal associations and pathogens.
The goal of this recovery strategy is to ensure that Deerberry persists in its natural habitat at known sites with no decline in population sizes over the short term and with increases in both the number of populations and population sizes until it is deemed that the species is no longer at risk in either of the two regions where it is found in Ontario.
The recovery objectives are:
- Persistence of Deerberry in its current habitat at all known natural and viable reintroduction sites, with population sizes remaining stable or increasing for the next 10 years and beyond.
- Identification of measures necessary to mitigate threats to the species and its habitat, and implementation of mitigation as appropriate.
- Completion of research and monitoring needed to document and assess habitat requirements, genetic diversity, life history, and population trends.
- Provision of adequate habitat for species recovery through planning for, protecting and restoring existing and potential habitat, and the augmentation, reintroduction and introduction of populations into suitable habitat.
Recommended approaches to help achieve these objectives are outlined in areas of management and stewardship, research and monitoring, restoration, and outreach and collaboration. Performance measures are given which tie recovery milestones to timelines over the next five years.
It is recommended that areas where natural populations or successfully introduced populations occur be prescribed as habitat within a habitat regulation. It is further recommended that the area within 30 metres around the external extent of each occurrence be prescribed as habitat within the regulation. Where occurrences are separated by more than 30 metres but there is contiguous suitable habitat in the intervening area (based on Ecological Land Classification), this area should also be included in the habitat regulation.