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Recovery Strategy for Multi-Species at Risk in Vernal Pools and other Ephemeral Wet Areas Associated with Garry Oak Ecosystems in Canada (Proposed)
This multi-species Recovery Strategy addresses the recovery of six endangered plant species inhabiting vernal pools and other ephemeral wet areas: bog bird's-foot trefoil (Lotus pinnatus), tall woolly-heads (Psilocarphus elatior), Juncus kelloggii (Juncus kelloggii), Ranunculus alismifolius var. alismifolius (water-plantain buttercup), rosy owl-clover (Orthocarpus bracteosus), and dwarf sandwort (Minuartia pusilla). In Canada, these species occur (or occurred) primarily in Garry oak and associated ecosystems on Vancouver Island and nearby Gulf Islands where they are largely restricted to low elevation, coastal areas. Although the range of all species extends into the United States, many of the species are widely disjunct from the U.S. populations. The Recovery Strategy comprises one component of the recovery program for Garry oak and associated ecosystems as outlined in the Recovery Strategy for Garry Oak and Associated Ecosystems and their Associated Species at Risk in Canada: 2001-2006.
Four main habitat types are distinguished in this strategy: vernal pools, vernal swales, vernal seeps, and seasonally wetted wetland margins. Vernal pools are spatially discrete, seasonally flooded depressions that form on top of impermeable layers such as hardpan, claypan, or bedrock. They occur under Mediterranean-type climatic conditions that provide for winter and early spring inundation, followed by complete or partial drying in summer. Vernal swales are similar to vernal pools, but are usually shallower with less defined boundaries and shorter inundation periods. Vernal seeps are shallow flows that occur where groundwater emerges on sloping terrain, usually on the lower slopes of hillsides. Seasonally wetted wetland margins are low-lying areas next to perennial streams, lakes, or marshes that experience temporary flooding during high water periods in the winter or spring, becoming dry again during the summer. These habitats are all naturally highly fragmented, occurring as small isolated patches along shorelines and on small islands. Urbanization has intensified their natural fragmentation, and species occurring within them face a diverse array of threats.
For successful implementation in protecting species at risk there will be a strong need to engage in stewardship on a variety of land tenures, and in particular on private land and on Indian Reserves. Stewardship involves the voluntary cooperation of landowners to protect Species at Risk and the ecosystems they rely on. It is recognized in the Preamble to the federal Species at Risk Act (SARA) that "stewardship activities contributing to the conservation of wildlife species and their habitat should be supported" and that "all Canadians have a role to play in the conservation of wildlife in this country, including the prevention of wildlife species from becoming extirpated or extinct." It is recognized in the Bilateral Agreement on Species at Risk, between British Columbia and Canada that:
"Stewardship by land and water owners and users is fundamental to preventing species from becoming at risk and in protecting and recovering species that are at risk" and that "Cooperative, voluntary measures are the first approach to securing the protection and recovery of species at risk."
Vernal pools and associated habitats are likely greatly diminished from their former abundance due to habitat conversion. Remaining habitat patches continue to be threatened by urban development and recreational demands, as well as by the encroachment of invasive alien shrubs, grasses and forbs. Fire suppression has further altered vegetation composition, hydrologic regimes and nutrient cycling, and increased fuel loading. Activities such as wetland draining, ditching, mowing, biking, dog-walking, utility maintenance, and garbage dumping also pose potential threats. Finally, as most populations are small and cover small areas, they may be inherently at risk from stochastic demographic and environmental events.
Further studies and trials will be needed to determine whether there are insurmountable barriers to the restoration of existing populations, the re-establishment of extirpated populations, and the establishment of new populations. However, following the precautionary nature of SARA, and to prevent undue extinctions or extirpations, the premise of this strategy is that recovery is technically and biologically feasible for all species.
Recovery goals and objectives
The long-term goals for recovery of each species include maintaining existing populations at current levels of abundance or greater, restoring species to their approximate historical area of occupancy and extent of occurrence through reintroductions or translocations, and ensuring longterm population viability.
The short-term (5-10 year) objectives for meeting the long-term goals are:
- To establish protection1 for existing populations through stewardship and other mechanisms.
- To engage the cooperation of all implicated landholders in habitat protection.
- To mitigate threats to habitat and survival from recreational activities, hydrologic alterations, and eutrophication.
- To mitigate threats to habitat and survival from secondary succession and invasive species encroachment.
- To restore to functioning condition a minimum of 10 historical (presently non-functional) vernal pools sites.
- To identify and rank 5-10 potential recovery (translocation) sites for each species at risk.
- To establish new populations (or subpopulations) of each species as per the recovery goal.
- To increase plant population sizes and/or population growth rates at extant sites as per the recovery goal.
- To establish Vernal Pool Conservation Areas at Uplands Park, Trial Island, Rocky Point, and Harewood Plains.
- To increase public awareness of the existence and conservation value of vernal pools and associated species at risk.
Broad strategies to address the threats and meet the recovery objectives include:
- Habitat protection and stewardship
- Landholder contact
- Ecological research
- Habitat restoration and site management
- Population augmentation and establishment
- Inventory and monitoring
- Public outreach and education
No critical habitat, as defined under the federal Species at Risk Act [s2], is proposed for identification at this time.
While much is known about the habitat needs of the species included within this recovery strategy, more definitive work must be completed before any specific sites can be formally proposed as critical habitat. It is expected that critical habitat will be proposed within one or more recovery action plans following: 1) consultation and development of stewardship options with affected landowners and organizations and 2) completion of outstanding work required to quantify specific habitat and area requirements for these species.
Following completion of key work such as development and implementation of a landowner contact program including stewardship activities, it is anticipated that proposed critical habitat may include habitat currently occupied by one or more species addressed within this recovery strategy, together with the adjacent upland areas that contribute directly to sustaining hydrologic functions within the primary habitat. A more complete definition of proposed critical habitat that also incorporates potential habitat will be addressed at a later date in the Recovery Action Plan stage. Based on current state of knowledge, potential critical habitat for recovery of these species may also include:
- Intact, naturally-occurring vernal pool, seep, or other ephemeral wet area greater than 1 m² on southeastern Vancouver Island and the Gulf Islands having the necessary ecological characteristics to serve as future recovery habitat for species at risk, along with assessment of a 20 m buffer zone around said feature
- The associated watershed and hydrologic features, including upland habitat, that contribute to the filling and drying of the above vernal pool or ephemeral wet area, and that maintain suitable periods of inundation, water quality, and soil moisture for species at risk germination, growth and reproduction, and dispersal.
Examples of activities likely to result in the destruction of critical habitat identified in the future
Examples of types of activities that would be expected to result in the destruction of any critical habitat that may be proposed in a recovery action plan include residential development, recreational off-road vehicle use, garbage dumping, logging road construction, utility corridor maintenance, wetland draw-down, draining, ditching and dredging, and bicycle jump construction.
Existing and recommended approaches to habitat protection
Current levels of protection for sites in this strategy range from "none" to "effectively protected." Potential approaches to habitat protection include stewardship agreements such as conservation covenants (a legal agreement by which a landowner voluntarily restricts or limits the types and amounts of development that may take place on the land to protect its natural features), direct land acquisition.
Schedule of studies to identify critical habitat
A formal definition of critical habitat will not be made until after a multi-step process to:
- determine the physical boundaries, biological attributes, and current ownership of occupied and potential habitat
- estimate the proportion of such habitat required to meet recovery targets
- identify threats to this habitat
- work with land owners and land managers to protect the species through stewardship and other mechanisms
- obtain peer review
The recommended completion date for these and other necessary steps is 2009.
Anticipated impacts on non-target species
This strategy recognizes the importance of the entire vernal pool community and also that of associated Garry oak ecosystems. By focusing on habitat protection, maintenance of hydrologic regimes, habitat restoration, and public outreach, it is expected that the approaches recommended here will benefit not only individual species at risk but the wider ecological community as well. A program of research to identify specific impacts on associated species at risk will be provided in the Recovery Action Plan.
Social and economic considerations
Recovery of species at risk and restoration of imperiled habitats associated with Garry oak ecosystems will contribute to biodiversity, health and functioning of the environment and enhance opportunities for appreciation of such special places and species thereby contributing to overall social value in southwestern British Columbia. The natural beauty of Garry oak ecosystems in the lower mainland, Gulf Islands and Vancouver Island are an important resource for British Columbians that provide for a robust tourism and recreation industry. Protecting these natural spaces, biodiversity and recreation values has enormous value to the local economy.
Some activities occurring in and around vernal pools and other ephemeral wet areas can impact sensitive species at risk. Deleterious impacts on species at risk and the integrity of these spaces may occur through activities that:
- modify or damage hydrologic processes important for maintenance of these sites,
- directly or indirectly introduce species, native or non-native, that alter the biotic or abiotic environment in a manner detrimental to processes important for the perpetuation of the vernal pool complex,
- directly damage or destroy an individual species at risk (such as through trampling or wheeled activities), or
- modify or destroy vernal pools or other ephemeral wet areas (such as through in-filling)
Vernal pools and other ephemeral wet areas are rare on the landscape and the overall land area required for physical protection of these sites is relatively small. Effective mitigation of potentially detrimental activities can be accomplished through careful planning and environmental assessment of proposed developments and site activities and sensitive routing of travel corridors and recreational activities.
Recovery actions could potentially affect the following socioeconomic sectors: recreation; private land development; forestry; operational and maintenance activities. The expected magnitude of these effects is expected to be low in almost all cases.
To address current knowledge gaps, further information on the following is needed: species distributions and population status; vernal pool distribution and status; appropriate restoration targets for vernal pool communities; species demography and population dynamics; microsite attributes; optimal disturbance regimes; response of habitats and species (including non-plant species) to restoration activities; seed storage and propagation techniques; and impacts of climate change.
Evaluation and measures of success
Performance measures that can be used to evaluate the progress of recovery include:
- Stated targets for plant abundance, viability, and occupied range
- Formalization of critical habitat designations through a Recovery Action Plan
- Level of protection achieved for proposed critical habitat
- Knowledge gaps addressed
- Number of high priority sites protected by acquisition, conservation covenants, or other stewardship actions
- Number of vernal pool sites improved through restoration activities
Timeline for completion of recovery action plan (RAP)
It is recommended that a draft Recovery Action Plan be completed by October 2009.
1 This may involve protection in any form including stewardship agreements and conservation covenants on private lands, land use designations on crown lands, and protection in federal, provincial and local government protected areas.
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