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Recovery Strategy for Multi-Species at Risk in Garry Oak Woodlands in Canada (Proposed)


2. Recovery

2.1 Key Characteristics of the Group of Species

The species included within this recovery strategy have some common biological characteristics and requirements, aside from sharing similar habitat (see section 1 for characteristics of Garry oak woodland habitat).

Key characteristics include:

  • The species in this strategy all occur over a similar range (California through Oregon to Washington and into southern British Columbia), with the populations in Canada being at the northernmost extent of this range.
  • When mature, all species appear to be well adapted to drought conditions.
  • The species are all relatively shade intolerant and are poor competitors.
  • These species all tend to have either poor germination or poor seedling survival rates.
  • All species have relatively limited dispersal, and the habitat is highly fragmented, making genetic exchange unlikely and limiting the opportunity for unoccupied habitat to be colonized.

2.2 Threats to Populations and Habitat

Threats to Garry oak woodland species have been identified in four major categories: direct human impact, exotic species, grazing and herbivory, and fire suppression. These threats are listed in Table 2 along with the degree to which they affect each species and its habitat. These categories are broad and interrelated, with threats likely having complex and cumulative effects on species at risk and their habitats.

Table 2. Present threats to populations of Garry oak woodland species at risk (P) and their habitat (H). The extent of the threat is described as Low, Moderate, High, or Unknown.
ThreatImpactdeltoid balsamrootwhite-top astersmall-flowered tonellaHowell's triteleiayellow montane violet
1. Direct human impact on habitat
a) Habitat loss (e.g., urbanization and agricultural development)P, HHighHighHighHighHigh
b) Habitat fragmentation and demographic collapsePHighHighHighHighHigh
c) Habitat degradation (e.g., recreation, land use/maintenance)P, HHighModerateModerateHighModerate
d) Restoration activities (e.g., mowing, pulling/cutting of shrubs, pesticide application)P, HLowHighLowHighModerate
2. Fire suppression
Changes to stand structure and plant community composition (shading, accumulation of thatch and woody debris, forest and shrub encroachment)P, HHighHighHighHighHigh
3. Invasion of exotic plant species
a) Exotic shrubs (shading, competition and habitat alteration)P, HHighHighLowHighHigh
b) Exotic grasses and forbs (shading, competition and habitat alteration)P, HLowHighModerateHighHigh
4. Grazing and herbivory
a) Herbivory or seed/bulb predation by exotic species (e.g., slugs, squirrels, rabbits, feral sheep)PHighModerateUnknownUnknownUnknown
b) Grazing by deerP, HHighHighUnknownUnknownUnknown

 

2.2.1 Direct human impact on habitat

The current extent of Garry oak ecosystems is estimated to be to less than 5% of their historical extent in the Victoria area (MacDougall et al. 2004, Lea 2002, Fuchs 2001). In addition, many sites continue to have no legal protection against future development since they occur on private land. Of the eight extant deltoid balsamroot sites in British Columbia, two are known to occur on private land. A significant portion of the deltoid balsamroot population at Tyee Spit was affected by residential development in 2003 (Ennis pers. comm. 2003). Of the 21 extant white-top aster sites, eight occur on private land. The single small-flowered tonella site occurs on private land on Salt Spring Island and could easily be extirpated by house construction on the waterfront property. Previous owners had plans for a residence on the site but these plans did not materialize. In recent years, Salt Spring Island has shown a marked increase in housing development with waterfront property at a premium. The population of the Island has increased by 78% between 1986 and 2001 and future projections indicate a further increase of 43% by 2026 (Adams pers. comm.2003). Of the 13 extant Howell's triteleiasites, five occur on private land. Of the 13 extant yellow montane violetsites, one occurs on private land.

Historical habitat loss has resulted in a matrix of highly fragmented sites, with limited or no dispersal between populations of all species within this strategy. Such small, isolated populations are at risk of inbreeding depression (Primack 1998). Loss of habitat and habitat fragmentation can also lead to pollinator limitation, as has been noted as a concern for white-top aster populations at Fort Lewis in Washington (Bigger 1999). In addition, habitat fragmentation can result in an increased invasion of exotic species, as well as alteration of ecosystem processes such as disturbance, nutrient, and hydrological regimes, due to edge effects.

Habitat loss can also threaten survival in protected areas where management plans have not been implemented, or where management plans do not include specific provisions for rare vascular plants. Road, trail, or other facility construction or maintenance in some municipal parks have had adverse effects on rare vascular plant populations in the recent past, such as at Uplands and Saxe Point Parks (Douglas pers. observ., Penny pers. comm. 2005). In addition, recreational use can result in trampling and removal of plants and/or flowers.

Degradation of habitat and direct damage to individual plants can also unintentionally result from restoration activities. Mowing, even in late summer, could negatively affect white-top aster since it is not dormant in mid-late summer, like most other forbs associated with Garry oak woodlands. Trampling of vegetation, accidental removal or disturbance of at-risk plants, exposure of soil, and inappropriate application of pesticides may all negatively affect the species in this strategy. The largest subpopulation of white-top aster at Mt.Tzuhalem was destroyed when a pile of pulled exotic shrubs were burned on the site. Carefully developed restoration plans and routine monitoring can ensure that restoration activities do not negatively impact plant species at risk in Garry oak woodlands.

2.2.2 Fire suppression

Suppression of both natural and human-induced fires following European settlement threatens all species in this strategy. The most noticeable threat is the expansion of shrub species, particularly common snowberry (Symphoricarpos albus), which effectively shade out native forbs, including those in this strategy. In the past, First Nations regularly burned much of southeastern Vancouver Island to maintain important wildlife and food-producing habitat (Roemer 1972, Turner 1999). Paleoecological evidence indicates that this burning by First Nations allowed for the persistence of Garry oak woodlands over the last several thousand years, by preventing the successional development of coniferous forest (Pellatt et al. 2001). Historical records indicate that the resulting landscape was a matrix of open prairies, rich meadows and shrub thickets (MacDougall et al. 2004). Many Garry oak woodland ecosystems (particularly the more mesic, deeper soil sites) are therefore dependant on fire as a disturbance mechanism to maintain the open canopy and understory, and remove thatch accumulation. Fire suppression also changes hydrological and nutrient regimes, and could negatively affect the species within this strategy.

The expansion of shrubs is evident at the Cowichan Garry Oak Preserve and at Somenos Lake, where snowberry dominates the understory vegetation in portions of these Garry oakwoodlands. Snowberry appears to effectively shade out and eliminate most herbaceous species so it is possible that, historically, the white-top aster, Howell's triteleia, and yellow montane violet populations were larger at these sites, but have been reduced by shrub encroachment. Yellow montane violet is particularly shade-intolerant and takes advantage of the high light levels, warm temperatures, and moist conditions which occur in early spring when leaves have not yet appeared on Garry oak and most shrubs. Yellow montane violet rarely occurs where dense shrub thickets of snowberry and broom dominate the vegetation and strongly shade the forest floor.

The reintroduction of fire could potentially threaten the populations and habitat of woodland species. With the accumulation of thatch and woody debris that has resulted from fire suppression, any fire that does occur will most likely burn at much higher temperatures than did historic fires. This would likely result in increased invasion of exotic plants, particularly common velvet-grass (Holcus lanatus) and/or orchard-grass (Dactylis glomerata). Any reintroduction of fire will need to be carefully conducted, and alternative methods of addressing this threat may be required (such as mowing and hand removal of shrubs, trees and debris). Fire suppression poses a particular problem for small-flowered tonella survival. The vegetation in the area would have naturally been maintained by fires, however, in their absence, high fuel loads have developed and a catastrophic, high-temperature fire could occur, which could completely destroy the entire small-flowered tonella population.

Public safety and potential for damage to property is a major concern in regards to bringing fire back to these ecosystems. Therefore, this will have to be addressed if fire reintroduction is proposed.

2.2.3 Invasion of exotic plant species

Habitat and populations of all five species at risk are threatened by invasive exotic species: the grasses early hairgrass (Aira praecox), sweet vernalgrass (Anthoxanthum odoratum), hedgehog dogtail (Cynosurus echinatus), a number of brome species (Bromusspp.) and orchard-grass are of special concern and, at most Garry oak woodland sites make up over 80% of the vegetative cover. These grasses compete with native plants for nutrients and water and may also alter habitat conditions, such as by increasing the litter layer. Competition from exotic grasses may also inhibit seedling establishment. In addition, shading and crowding by the invasive shrub, Scotch broom (Cytisusscoparius), is a threat to deltoid balsamroot, white-top aster, Howell's triteleia, and yellow montane violetpopulations at several sites.

The small-flowered tonella habitat has been significantly altered by the presence of introduced species which now dominate the vegetation in the area. There is a particularly high cover of introduced grasses, especially bromes, at the site.

The extent of the impact that introduced plant species may have had on yellow montane violet remains unclear. Most grass species in the violet's habitat, except orchard-grass, grow slowly in the spring and do not appear to compete with the violet for light until it has completed flowering and set seed. However, the dense turf formed by grasses may still effectively prevent the successful germination and establishment of the violet's seedlings and may also compete for nutrients and water.

2.2.4 Grazing and herbivory

The effects of grazing and seed or bulb predation are largely unknown for the species addressed in this strategy, particularly for small-flowered tonella, Howell's triteleia, and yellow montane violet, but may have a considerable impact on regeneration and survival, particularly of young plants. An unstudied potential threat to Howell's triteleiais the increasing numbers of the introduced eastern grey squirrel (Sciurus carolinensis), since lily bulbs are known food sources for squirrels.

Grazing by invertebrates and mammals has been observed on deltoid balsamroot, particularly in more disturbed sites, and may threaten the survival of younger balsamroot individuals (Roemer 2005). Some populations of white-top aster in parks have also been observed to be heavily grazed by deer as well as rabbits (Roemer 2005). Grazing may not always be a significant threat, however, since little grazing of white-top aster has been observed at Little Saanich Mountain, despite its high deer population (Fairbarns 2005). Yellow montane violet on Mt. Tuam appears to be heavily browsed by feral sheep, and also likely by deer.

Seed predators may threaten both deltoid balsamroot and white-top aster. Only a few intact seeds are often found in each of the many-flowered balsamroot seed heads. At Fort Lewis, Washington, Bigger (1999) found that two-thirds of the white-top asterramets (essentially clonal stems) in his study were attacked by seed predators, mostly larvae of a coleopteran (beetle) species. This seed predation was also found to be correlated with patch size, with twice as many seeds damaged in large patches as in small. In Canada, seed predation of white-top aster is currently only a moderate threat, since a recent study indicates that few stems appear to flower, apparently due to summer drought (Fairbarns 2005).

2.3 Critical Habitat

No critical habitat, as defined under the federal Species at Risk Act [s2], is proposed for identification at this time in the 'Woodlands Recovery Strategy'.

While much is known about the habitat needs for survival and recovery of the species included within this recovery strategy, more definitive work must be completed before any specific sites can be proposed for protection 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.

A schedule of studies outlining work necessary to identify critical habitat is found below (Section 2.3.4). Notwithstanding the above, information on the current state of knowledge on the habitat needs and sites of occupation of the species included in this recovery strategy are provided below.

This section describes, to the extent possible, the occupied and potential habitat for each species, examples of activities which are likely to destroy critical habitat, and a schedule of studies required to define critical habitat.

Occupied habitat is described for four of the five species included in this strategy. Critical habitat will be proposed in the Recovery Action Plan stage after consultation with land owners and land managers.

2.3.1 Occupied habitat

All currently occupied habitat on federal, municipal lands as well as any sites that are under imminent threat, and are described below.

Deltoid balsamroot

Occupied habitat for deltoid balsamroot is found on the southeast coast of Vancouver Island, in Garry oak woodlands from Langford and Colwood to Victoria, as well as at Duncan and Campbell River. These sites (see "Description of the needs of the species" section for details) are typically dry in summer and well-drained in winter, and exposed or only partially shaded by shrubs or trees.

Occupied habitat for Deltoid balsamroot occurs in eight locations in Canada; one location atis Fort Rodd Hill National Historic Site has the species' only population on federal land (other than Indian Reserve land). Of the seven remaining balsamroot sites, two are on private land and therefore lack any sort of protection, one occurrence is on an Indian Reserve (Tyee Spit) where active protection and restoration of the species occurs, and the others are within protected areas.

White-top aster

Occupied habitat for white-top aster is found on the southeast coast of Vancouver Island and on Trial Island and Hornby Island. It occurs in Garry oak woodlands, or in meadows from Trial Island and Victoria, west to Colwood, Langford and Sooke, and north to Duncan, and Nanaimo. In addition, one population is known from the Port Alberni area. These sites (see "Description of the needs of the species" section for details) are dry in summer and well-drained in winter, and exposed or only partially shaded by shrubs or scattered trees. Soils are typically shallow (i.e. < 30 cm).

White-top aster is currently known from 21 extant sites. Sites with strong potential for protection or that have inordinately high value for the survival of the species in Canada include the federally-owned land on Trial Island and on Little Saanich Mtn. The percentage of the white-top aster population that is on the federally-owned land at these sites is unknown, therefore, mapping and inventory will be required to ensure that sufficient critical habitat can be designated at these sites. Important occupied habitat also occurs on private land in the Harmac area southeast of Nanaimo. This property is slated for development (Christy 2005, Fairbarns 2005) and contains the largest population of white-top aster in Canada.

Small-flowered tonella

Small-flowered tonella only occurs on one steep talus slope near Sansom Narrows, Salt Spring Island. This site (see "Description of the needs of the species" section for details) occurs on talus in open bigleaf maple-arbutus (Acer macrophyllum-Arbutus menziesii) forests, is dry in summer, well-drained in winter, and exposed. Additional habitat may be required for this species, and will be identified in the Recovery Action Plan after consultation with relevant landowners.

Howell's triteleia

Occupied habitat for Howell's triteleia is found along the southeast coast of Vancouver Island, between Victoria and Metchosin, including Langford and Saanich, north to Duncan. Howell's triteleiaoccurs on moderately deep soils and rock outcrops in Garry oak woodlands. These sites (see "Description of the needs of the species" section for details) are dry in summer and well-drained in winter, and may be shaded by shrubs and scattered trees.

Of the 13 extant Howell's triteleia sites, seven occur within parks or other protected areas. One occurs on an Indian Reserve, and five are found on private property. There are no known development plans for the sites on private properties.

Yellow montane violet

Occupied habitat for yellow montane violetis found along the southeast coast of Vancouver Island, between Victoria and Metchosin, including Langford and Saanich, north to Duncan and Nanaimo, as well as on Salt Spring Island. One historical location was reported from the Comox area. Yellow montane violet habitat occurs in Garry oak woodland and meadows with deeper soils and less exposed bedrock (see "Description of the needs of the species" section for details). Habitat also includes some relatively steep rocky slopes, with pockets of soil, as well as some open (very little or no Garry oak or other tree cover) grass-dominated meadows where soils are relatively deep and likely retain some moisture during summer drought conditions.

Yellow montane violet is known from 13 sites in Canada: one site federal land on Little Saanich Mountain, nine are in parks or other protected areas, and three are on private land.

2.3.2 Potential habitat

The previously discussed occupied habitat is insufficient for the full recovery of the species within this strategy as defined under the species-specific recovery goals. Additional habitat will be required to meet these goals. However, further research is required before appropriate additional habitat can be proposed as critical habitat, and to determine feasibility of translocations including re-introductions. Selected potential habitat will also likely require restoration actions before recovery is attempted.

Ideally, all remaining Garry oak woodlands should be considered as potential habitat for one or more of deltoid balsamroot, white-top aster, Howell's triteleia, and yellow montane violet throughout their known historical range (see Section 3 for details on historical sites). Quality habitat should have an open tree canopy, well drained or seasonally dry soils, and a relatively low amount of invasive exotic species (particularly grasses and Scotch broom). Since these four species at risk sometimes occur together and require similar habitat, recovery actions for all four could be implemented simultaneously. In addition, populations of Howell's triteleia and yellow montane violetat extant sites could be increased dramatically, with the removal or reduction of threats to the populations and habitat.

Since small-flowered tonella is only known from one site in Canada, additional habitat on Salt Spring Island may need to be identified in order to increase the potential for this species' recovery.

2.3.3 Examples of activities likely to destroy any critical habitat identified in the future

Habitat loss through urbanization or agricultural development and other land use change is the most obvious activity that can destroy critical habitat. However, this threat can be effectively eliminated through habitat protection including stewardship. Maintenance activities (e.g., trail building and repair) and recreational use (e.g., hiking, mountain biking, ATV's) also can destroy critical habitat, and protection of critical habitat will require the cooperation of land owners or land managers.

Protection of critical habitat will involve restoration activities at most sites following guidelines provided by the Garry Oak Ecosystems Recovery Team to support land owner stewardship. Invasive exotic species are a serious threat to critical habitat, changing the plant community composition and structure and nutrient and water cycling regimes, essentially making the habitat unsuitable for the species at risk addressed in this strategy. Fire suppression is also resulting in a loss of critical habitat, by allowing conifers and shrubs to invade the open understory that was previously maintained by natural fires and by First Nations burning. However, restoration activities such as invasive plant removal (weeding or pesticide use), thatch removal (mowing or fire) and shrub and conifer removal (cutting or prescribed burning) can trample or otherwise destroy critical habitat, particularly if such activities are conducted during the growing season. Restoration activities may also be unsuccessful and therefore may have an overall deleterious effect on critical habitat (e.g., removal of shrubs resulting in erosion or invasion by exotic grass species).

2.3.4 Schedule of studies to identify critical habitat

Currently known important habitat attributes are discussed in detail in Section 3 of this strategy. A table of Garry oak woodland sites occupied by one or more of the species in this strategy has been compiled (Table 3) as a starting point for identification of critical habitat. The known population size, quality of habitat, and level of protection, were used to qualitatively assess each site's potential for recovery.

Further research is required to define proposed critical habitat for the five species in this recovery strategy. Research projects include:

  • Use established mapping techniques (applied during phenologically appropriate periods), to delimit the boundaries of all occupied habitats and to confirm and consult with landowners. Suggested completion date: 2008.
  • Conduct detailed surveys of occupied habitats to better understand habitat attributes of critical habitat, including: soil depth and texture, slope and aspect, and plant community composition. Suggested completion date: 2009.
  • Identify, map, and classify unoccupied Garry oak woodlands on southeastern Vancouver Island and the adjacent Gulf Islands. Suggested completion date: 2010.
    • Identified potentially suitable habitat for Garry oak woodland species at risk should be assessed both for possible unknown extant populations of species at risk and for suitability of establishing new populations if necessary.
  • Compile information and research to propose critical habitat. Suggested completion date: 2010.
Table 3. Garry oak woodland species land tenure, population size, and qualitative assessment of site potential for recovery
SiteLand TenurePopulation Size (# of stems)Assessment of Site Potential for Recovery
deltoid balsam-
root
white-
top
aster
small-flowered tonellaHowell's triteleiayellow montane violetExcel-lentGoodMode-ratePoorUn-known
Albert HeadRegional Park   9     X
Beacon HillMunicipal Park1  200465  X  
Bear Hill Regional Park 300  78    X
Camas HillPrivate 30       X
Canoe CovePrivate   2    X 
Christmas HillPrivate?    86   X 
Cordova BayPrivate 560      X 
Cowichan Garry Oak PreserveNature Conservancy of Canada 858 4503200X    
Cowichan River EstuaryPrivate   62    X 
Darnley Rd.Private Not recorded       X
Downes Pt.Private 7,300     X  
Falaise ParkMunicipal Park    59   X 
Fort Rodd HillNational Historic Site5       X 
Francis-King ParkRegional Park 438-478     X  
Francis-King Park, SW ofPrivate36Unknown      X 
Gordon HeadPrivate   51     X
HarmacPrivate 24,000     X  
Holmes PointPrivate?    Un-
known
    X
Horth HillRegional Park   3    X 
Island View BeachIndian Reserve   1    X 
Kangaroo Rd.Private Unknown       X
Little Saanich Mtn.Federal 12,000-45,000  25 X   
Maple Mtn.Municipal Park 20        
Mary HillDND    Un-
known
    X
Mill HillRegional Park553,990    X   
Mt. FinlaysonProvincial Park 200     X  
Mt. MaxwellProvincial Park & Ecological Reserve    Possi-
bly
extir-
pated
 X   
Mt. TolmieMunicipal Park 30  Un-
known
   X 
Mt. TuamPrivate (Federal lease?)    53+   X 
Mt. TzuhalemEcological Reserve463850  55X    
Mt. Tzuhalem, base ofPrivate   6   X  
Mt. WellsRegional Park 158    X   
Playfair ParkMunicipal  Park    282  X  
Sansom NarrowsPrivate  236-316   X   
Skirt MountainPrivate1       X 
Smith HillCity Park    490  X  
Somenos LakeProvincial Park   12640,000+X    
St. Peter's ChurchPrivate    5   X 
Thetis LakeRegional Park100  1   X  
Trial IslandFederal & Provincial 3000-8000     X  
Tyee SpitIndian Reserve500     X   
Uplands ParkMunicipal Park 600  95  X  
White Rapids Rd.Private 15      X 
William Head Rd.Private   14    X 
Witty's Lagoon Regional Park   43   X  
Woodley RangeEcological Reserve 500       X

2.4 Recovery Feasibility

Recovery is broadly defined as "any improvement in a species' probability of long-term persistence in the wild" (Environment Canada et al. 2004). Recovery of species at risk to historical extent may not be feasible due to habitat loss, or inability to completely eliminate all threats or other limitations. Further study will be required to determine whether there are barriers to restoration of specific populations of the species, or to reintroduction of new populations. The premise of this strategy is that recovery is technically and biologically feasible (Table 4).

Table 4. Recovery feasibility for all species
Criteriadeltoid balsamrootwhite-top astersmall-flowered tonellaHowell's triteleiayellow montane violet
1. Are individuals capable of reproduction available to support recovery?YesYesYesYesYes
2. Is habitat available for recovery or could it be made available through recovery actions?YesYesYesYesYes
3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?YesYesYesYesYes
4. Do the necessary recovery techniques exist and are they demonstrated to be effective?YesYesYesYesYes

2.5 Goals, Objectives and Broad Approaches/Strategies

2.5.1 Goals

Recovery goals are presented in Table 5 for all five species included in this strategy. Although these species differ in some respects of life history and microhabitat requirements, the overlying goals remain relatively constant for all. Since persistence of species at risk is the basic goal of recovery (see "Recovery feasibility" above), the first goal for all species is to maintain existing populations at existing or greater numbers. This ensures short-term persistence of the species in the strategy and provides a baseline standard for Goal 3 (see description of Goal 3 below). In most cases, removal of threats should allow populations to stabilize or increase in size. However, if monitoring indicates a population decline, augmentation may be required to increase population numbers.

Population viability analyses (PVA) have not been conducted for the species within this strategy. Until these analyses are conducted, specific recovery targets are instead based on historical records and the best available knowledge on the species. Goal 2 aims to restore or maintain the area of occurrence and area of occupancy of the species, based on estimations of historical abundance and distribution, to provide a greater likelihood of long-term persistence.

The aim of Goal 3 is to achieve viable populations of all species, with either a high or moderate (in the case of small-flowered tonella) probability of persistence. Probability of persistence can be predicted through demographic models which integrate birth and death rates that determine changes to population size (Caswell 2001 in Miller 2004). The discrete population growth rate, l, is the most critical demographic parameter for species at risk management. When λ <1, the population is projected to decline; when λ = 1, the population is stable; and when λ >1, the population is projected to grow. Due to variation in λ, a single estimate is not usually a reliable predictor of long-term population dynamics. Stochastic simulations are used to provide more accurate indicators of long-term trends, by accounting for yearly variation in λ (indicated by log λs) (Caswell 2001 and Caswell and Kaye 2001 in Miller 2004).

Table 5. Recovery goals for all species
SpeciesRecovery goals
deltoid balsamroot
  • To maintain extant populations of deltoid balsamroot at current levels of abundance or greater.
  • To restore deltoid balsamroot to its estimated approximate historical extent of occurrence and area of occupancy [establish a minimum of two new self-sustaining populations (in the Victoria and Metchosin area)].
  • Attain, with a high probability of persistence3, a fully viable Canadian population of deltoid balsamroot.
white-top aster
  • To maintain extant populations of white-top aster at current levels of abundance or greater.
  • To restore white-top aster to its estimated approximate historical extent of occurrence and area of occupancy (establish a minimum of two new self-sustaining populations in the Victoria area).
  • Attain, with a high probability of persistence4, a fully viable Canadian population of white-top aster.
small-flowered tonella
  • To maintain the extant population of small-flowered tonella at the current level of abundance or greater.
  • To maintain the approximate current extent of occurrence and increase the area of occupancy (at least two additional subpopulations on Salt Spring Island).
  • Attain, with a moderate probability of persistence5, a fully viable Canadian population of small-flowered tonella.
Howell's triteleia
  • To maintain extant populations of Howell's triteleia at current levels of abundance or greater.
  • To restore Howell's triteleia to its estimated approximate historical extent of occurrence and area of occupancy [establish a minimum of two new populations (in the Victoria and Metchosin area)].
  • Attain, with a high probability of persistence4, a fully viable Canadian population of Howell's triteleia.
yellow montane violet
  • To maintain extant populations of yellow montane violet at current levels of abundance or greater.
  • To restore yellow montane violet to its estimated approximate historical extent of occurrence and area of occupancy [establish a minimum of two new populations (in the Victoria and Metchosin area)].
  • Attain, with a high probability of persistence5, a fully viable Canadian population of yellow montane violet.

3 After 10 years, population size at four protected localities is stable or increasing, with the combined population exhibiting a projected stochastic population growth rate (log λs) ≥1.0. (Population trends will be estimated using data collected from annual monitoring. Prior to the initiation of detailed monitoring surveys and/or demographic study, a pilot study should be undertaken to determine if 10 years represents an appropriate time scale to measure population changes for individual species at risk and to guide the development of sampling designs with the statistical rigor to detect such changes.)

4 After 10 years, population size at 10 protected localities is stable or increasing, with the combined population exhibiting a projected stochastic population growth rate (log λs) ≥1.0. (Population trends will be estimated using data collected from annual monitoring. Prior to the initiation of detailed monitoring surveys and/or demographic study, a pilot study should be undertaken to determine if 10 years represents an appropriate time scale to measure population changes for individual species at risk and to guide the development of sampling designs with the statistical rigor to detect such changes.)

5 After 10 years, total population size at Salt Spring Island is at least 1000 individuals, with the population exhibiting a projected stochastic population growth rate (log λs) ≥1.0.

2.5.2 Objectives

The short-term recovery objectives outlined in Table 6 apply to all species in this strategy and contribute to achieving the recovery goals. The first objectives are clearly focused on protecting species and habitat, acquiring information, and monitoring extant sites. These first steps are important requirements for appropriate recovery implementation over the long term, especially in regard to habitat restoration and augmentation of current populations and establishment of additional populations.

Table 6. Common recovery objectives for Garry oak woodland species at risk
ObjectiveSuggested Time to Completion
1) Establish protection for existing populations through stewardship and other mechanisms..5 years
2) Involve landowners in habitation protection and species recovery.5 years
3) Monitor populations and habitat to determine population trends and demography, and assess threats and habitat conditions.ongoing
4) Identify and define habitat attributes of populations including: soil depth and texture, slope and aspect, and associated plant communities.5 years
5) Conduct biological and ecological research to better understand species at risk biology and ecological requirements and effects of exotic species and fire suppression.ongoing
6) Establish site-specific, adaptive management plans for habitat restoration.5 years
7) Identify and rank recovery (translocation) sites for each species.5 years
8) Augment population numbers where required as per recovery goals.5-10 years
9) Establish new populations or subpopulations of each species as per recovery goals.5-10 years
Effective protection of existing populations

Long-term protection for extant populations of species at risk needs to be secured whenever possible. This may be conducted through a variety of mechanisms, including land acquisition by public agencies or private conservation organizations, development of formal stewardship agreements or conservation covenants with landowners, or legislative protection through the Wildlife Act.

Landowner participation

Landowner cooperation and participation in habitat protection and species recovery is crucial for effective recovery. This will require proactive communication between recovery teams and stewards, including land managers and property owners. Stewards should also be involved in the recovery process, and encouraged to participate in restoration projects and species monitoring and collaborate with researchers.

Monitoring of populations and habitat

A monitoring program for all species at risk in this strategy will be required in order to determine population trends, and identify new and ongoing threats to species and habitats. Monitoring programs should be developed in conjunction with land managers and owners and should focus on habitat condition, threats, and associated population responses, as well as on providing detailed assessments of population size and demography. Monitoring should be conducted on an annual basis, at a minimum. Information gathered through monitoring should be forwarded to relevant stakeholders and agencies, and incorporated into site management plans.

Identification of habitat attributes

A detailed inventory and survey, including mapping, of Garry oak woodland species at risk habitat on southern Vancouver Island and the adjacent Gulf Islands is necessary to understand habitat requirements of the species. The information gathered should be utilized in conjunction with monitoring information to aid in identifying appropriate critical habitat and establishing research priorities. Data collected should include:

  • numbers of plants, including general age classes
  • area of occupancy ()
  • substrate type (e.g., soil texture, depth, presence of organics)
  • site, slope and aspect
  • stand structure and age
  • plant community composition including vegetative cover and/or numbers of community associates, especially exotics
Biological and ecological research

In addition to investigating population trends and habitat attributes, research on the biology and community ecology of the species in this strategy is necessary for effective site management and recovery. Permanent study plots should be established at one or more sites for each species at risk in this strategy, for use in addressing research questions.

Information on demographics (including seedling and juvenile survival, individual plant longevity, and seed bank longevity), genetics, germination characteristics, pollination, and dispersal is required to better understand population dynamics. To address threats posed by exotic species, research on exotic species biology, eradication, and effects on species at risk is necessary. Effects of fire suppression, and impacts of fire reintroduction or other disturbances or maintenance methods (such as mowing and cutting of shrubs and/or trees), should also be studied.

Habitat restoration and management plans

Habitat restoration is required at all sites to address threats from exotic and native shrubs, including thatch accumulation as a result of invasion by exotic grasses and fire suppression. This may require various treatments including cutting of trees and/or shrubs, weeding, mowing, and/or controlled burning to restore habitat and enhance germination and seedling survival and reduce competition. Restoration activities should be based on site-specific management plans, and should be adapted as required (from information provided by monitoring and research).

Identification and ranking of recovery sites

Upon completion of Objective #4, in conjunction with information gathered through Objective #5, additional habitat for the species at risk in this strategy should be identified and ranked in order of priority and feasibility.

Population augmentation and establishment

Population monitoring may indicate a decline in individuals at extant sites, despite recovery action to reduce threats. In order to meet recovery goals, planting of seedlings or cuttings at extant sites may therefore be required to augment existing populations. Additional populations may also need to be established at formerly occupied sites in order to restore the species to an approximation of its historical extent of occurrence. Prior to any population augmentation or establishment, site restoration will likely need to be conducted and any potential or actual threats to the species and/or habitat will need to be addressed.

The Recovery Action Plan will include augmentation and translocation plans for the species in this strategy. These plans will further outline the specific conditions under which augmentation translocations should be implemented, and will provide guidance based on the "Guidelines for Translocation of Plant Species at Risk in British Columbia" (BC Ministry of Environment, in draft.)

2.5.3 Broad Approaches to Address Threats

The similar goals and objectives for the species included in this strategy can be addressed through four broad approaches that can be applied to all species: habitat protection/stewardship, site management, information collection, and population augmentation/establishment. The use of these broad approaches can increase efficiency and cost-effectiveness of recovery actions. The approaches to effect recovery of the species included in this strategy are listed in Table 7 and are linked to the objectives and threats of the species. In addition, examples of specific steps and outcomes or deliverables are identified.

Table 7. Broad approaches to effect recovery for all species within the strategy
PriorityObj. No.Broad ApproachThreat(s) addressedSpecific StepsOutcomes or Deliverables
(identify measurable targets)
High1,2Habitat Protection and Steward-ship1 - 4
  • Prioritize sites for urgency (see Table 3) of attention
  • Identify and contact private owners
  • Determine and implement ideal protection strategies for individual sites (acquisition, easement, stewardship, etc.) when feasible
  • Establish communication and cooperation with land owners and stewards and engage in recovery
  • Prioritized list of private sites for potential securement
  • Contact established with landowners and protection measures in place where feasible
  • Where protection of private land not feasible, stewardship roles established when possible
  • All protected areas implement specific provisions for species at risk management
High2, 3, 4, 5, 6, 8Site Manage-ment1b, 1c, 1d, 2, 3, 4
  • Implement actions to reduce impact of invasive exotic species on habitat and individual plants (based on research)
  • Minimize damage to individual plants through application of netting and/or diatomaceous earth or other means when necessary
  • Implement and adaptively manage a mowing, weeding and/or controlled burning regime where determined appropriate
  • Increased health of extant individuals and populations
  • No decrease in population sizes over 5-10 year period
High3,4,5,6,7

Information collection

  • inventory
  • monitoring
  • research
1b, 1c, 1d, 2, 3, 4
  • Conduct baseline inventory of sites and habitat attributes
  • Map sites accurately for long term monitoring
  • Conduct research to better understand demographic patterns
  • Conduct research on non-native species biology, eradication, and interaction with species at risk
  • In situ and ex situ experiments to address knowledge gaps regarding competition, germination, survival etc.
  • GIS database of accurate baseline site information
  • Completion of basic research on habitat attributes, phenology, seed bank longevity, germination characteristics, seedling and juvenile survival, and individual plant longevity
  • Basic understanding of threat from non-native species at sites
Medium3,4,5,7, 8, 9Population Augmentation and Additional Population Establishment1a, 1b, 1c, 3b, 4a
  • Apply experimental data from research to create recovery strategies for extant populations
  • Implement population recovery actions at extant sites by enhancing recruitment and survival
  • Apply knowledge gained from research, experiments, and population recovery to create strategies for additional population establishment
  • Implement establishment of new populations at suitable sites if required and feasible
  • Increased health of extant individuals and populations
  • No decrease in population sizes over 5-10 year period
  • Experimental populations established
Habitat Protection and Stewardship

Habitat loss and fragmentation has historically been the most serious threat affecting the species in this strategy. Habitat protection and stewardship agreements can be used to effectively address this threat. Sites should be prioritized by urgency of attention, after mapping and surveying of populations and habitats. Landowners should be identified and contacted to discuss feasible protection strategies, and to establish open communication and cooperation in protecting species at risk in Garry oak woodlands.

Site Management

Site maintenance and restoration activities need to be implemented to reduce the impact of invasive exotic species on habitat and individual plants. Caution must be used to minimize damage from herbivores and detrivores to individual plants (particularly younger deltoid balsamroot plants) through application of netting and/or diatomaceous earth or other means when necessary. An adaptive management approach may be implemented to design the most effective site management approach for each location.

Information collection: inventory, monitory and research

Baseline inventory, monitoring and research on populations and habitats is required to better understand species at risk in Garry oak woodlands. Necessary studies include:

  • an accurate assessment of current populations to establish baseline population numbers for long term monitoring
  • research to better understand species at risk biology, population dynamics and demographic patterns, and ecological requirements
  • research on exotic species biology, eradication, and interaction with species at risk
  • In situ and ex situ experiments to address knowledge gaps regarding competition, germination, survival etc.
Population Augmentation and Establishment

The first priority for recovery of the species in this strategy is the protection and management of currently occupied habitats. The Canadian Botanical Association (2004) recommends that existing populations should not be moved to more convenient locations as compensatory mitigation planting. Translocations and reintroductions should be used as a tool for augmenting the number of individuals at existing sites and increasing the number of existing populations (as well as the extent and area of species occurrence). In addition, populations used as source material should be carefully monitored to ensure that collection does not damage donor populations. Reintroduction of plants at extirpated sites should not replace protection and management of existing populations.

Successful introductions/reintroductions require the active participation of the GOERT Plants at Risk RIG and must follow augmentation and translocation plans to be provided in the Action Plan (see "Objectives" section above). It must be ensured that appropriate habitat exists at reintroduction sites and that threats to new populations have been adequately managed or eliminated. (e.g., through site preparation and restoration, control of competition, watering, fencing, etc.).

2.6 Effects on Other Species

Garry oak woodland species are inherently tied to ecosystem processes which have been significantly altered since the arrival of European settlers (e.g., changes to fire regime and stand dynamics and spread of invasive exotic species). As a result, most of the activities suggested in this strategy will also benefit other species within the ecosystem. However, this assumption should not necessarily be accepted, and specific recovery activities should always consider effects on other species, particularly other species at risk. Because of the large number of species at risk and the high concentrations of rare species at some locations, it is not possible to describe all possible positive and negative impacts associated with recovery. These management impacts must be addressed at a later stage either in the Recovery Action Plan (RAP), or during on-site evaluations.

To avoid potential conflicts with other recovery actions planned or underway, open communication should be maintained with the following GOERT Recovery Implementation Groups (RIGs) and Steering Committees:

  • Inventory, Mapping & Plant Communities RIG
  • Conservation Planning & Site Protection RIG
  • Restoration and Management RIG
  • Invertebrates at Risk RIG
  • Vertebrates at Risk RIG
  • Research RIG
  • Communication, Coordination & Public Involvement RIG
  • Invasive Species Steering Committee
  • Native Plant Propagation Steering Committee
  • Fire & Stand Dynamics Steering Committee

2.7 Knowledge gaps common to all or most species

The strategic approaches outlined in the umbrella Garry oak and associated ecosystem strategy (GOERT 2002) identify and discuss knowledge gaps that pertain to Garry oak ecosystems. Particular information gaps that may inhibit recovery of the species included in this strategy will be addressed through research activities as discussed in the objectives and broad approaches sections. The most pressing concerns regarding recovery of woodland species are the lack of information on species distribution and population status, species demography, and effects of fire suppression, exotic species and restoration activities on species and habitats.

Species-specific biological information gaps common to all species within the report include: understanding of competition (especially with exotic species), and demographic patterns (e.g., seed bank longevity, germination characteristics, seedling and juvenile survival, individual plant longevity). Little or no information is available regarding the population dynamics of these species including the extent to which seed remains viable in the soil, the frequency with which recruitment occurs from established seedlings, and the longevity of mature plants (for perennials).

In addition, research on white-top aster in the U.S. has been unable to find a correlation between the species' reproductive biology and its rarity since seed production has been found to be within the normal range for Asteraceae (Clampitt 1987, Giblin and Hamiliton 1999). Douglas and Illingworth (1996) report a relatively high percentage of flowering stems (30-50%), though Fairbarns (2005) found very few flowering stems. There is little known about Howell's triteleiain terms of biology or ecology throughout its range. No information is available regarding the population dynamics of this species including the extent to which seed remains viable in the soil, the frequency with which recruitment occurs from established seedlings, and the longevity of mature plants.

2.8 Actions already completed or underway

This section describes some of the relevant recovery actions already completed or underway that directly apply to one or more of the species at risk. Some actions listed have been adapted from Maslovat and Fairbarns (2005) and Miller (2005). Several actions are from a list of active research compiled by Mike Meagher of the GOERT Research RIG (Meagher pers. comm.2004). In addition to these local actions, research and management or restoration techniques in the United States should be considered, such as those outlined by Fitzpatrick (2004).

2.8.1 Other recovery strategies

2.8.2 Public outreach and education

  • Preparation and distribution of Fact Sheets for Species at Risk in Garry Oak and Associated Ecosystems in British Columbia (GOERT 2003).
  • Public education, including workshops, hosted by GOERT
  • Mount Tzuhalem stewardship co-ordinator hired by Cowichan tribes for off-reserve outreach and public education on species at risk.
  • CRD Parks has developed a draft communications plan for the Sooke Hills Wilderness Area and Mount Wells Regional Park which calls for installation of interpretive signs at Mount Wells explaining the presence of rare species and the need for park users to stay on trails. This information will also be posted at their website.

2.8.3 Landowner contact

  • Oak Bay Parks has been contacted regarding protection of species at risk in Uplands Park.

2.8.4 Habitat protection

  • GOERT has inventoried and compiled a list of priority unprotected Garry oak woodland sites and sponsored and facilitated workshops with potential partners to discuss their protection and securement.

2.8.5 Habitat mapping, surveying, and inventory

  • Numerous surveys of Garry oak woodlands have been conducted on behalf of the BC Conservation Data Centre, Interdepartmental Recovery Fund, GOERT, and other agencies by experienced botanists.
  • A Sensitive Ecosystem Inventory has been completed for east Vancouver Island and the Gulf Islands (Ward et al.1998).
  • A rare plant inventory and mapping has been completed at Uplands Park/Cattle Point, Oak Bay (Collier et al. 2004) and rare plant inventory and mapping has been conducted in Beacon Hill Park, Victoria.

2.8.6 Plant Species at Risk Research

  • GOERT has supported, initiated and/or continued research on
  • restoration strategies
  • effects of mammalian herbivores and exotic plants on plant diversity
  • indigenous ecological management
  • fire history
  • Staff from the Pacific Agri-Food Research Centre have tested propagation techniques for deltoid balsamroot, white-top aster, and yellow montane violet (Ehret et al. 2004).
  • Deltoid balsamroot seeds from Mt.Tzuhalem have been propagated by Sylvan Vale Nursery, and planted at Somenos.

2.8.7 Invasive Species Research and Removal

  • GOERT has compiled an annotated bibliography of invasive species in Garry oak ecosystems, as well as developed and piloted a Decision Support Tool for invasive species management.
  • GOERT has supported, initiated and/or continued research on Scotch broom and common snowberry encroachment, regeneration and management.
  • Research at the Pacific Forestry Centre has been conducted on impact and management of the exotic invasives: Scotch broom, gorse (Ulex europaeus), daphne (Daphne laureola), and English ivy (Hedera helix), as well as monitoring spread of Scotch broom and gorse in British Columbia. Removal of invasive species at Fort Rodd Hill National Historic Site, including at the deltoid balsamroot site (Reader, pers. comm.), invasive species removal at Mt. Tzuhalem Ecological Reserve, removal of Scotch broom and gorse from Trial Island.

2.8.8 Management Plans

  • Somenos Marsh Management Plan (Williams and Radcliffe 2001). Website: http://www.northcowichan.bc.ca/pdf/somenos_mgt_plan.pdf
  • CRD Parks Master Plan (PDF Format, 4.72MB) (Capital Regional District Parks 2000) and associated management plans for invasives, rare plant monitoring, and individual park issues.
  • Uplands Park/Cattle Point Rare Species Management Plan (in progress).
  • Mount Tzuhalem Ecological Reserve: Purpose statement (BC Parks 2003a).
  • Trial Islands Ecological Reserve: Purpose statement (BC Parks 2003b).
  • In 2003-4 and 2004-5 the municipality of Oak Bay and HSP are developing guidelines for the long-term management of all rare species at Uplands Park and Cattle Point.

2.8.9 Habitat Restoration

  • Mill Hill Regional Park Restoration Plan: pilot project for future restoration in CRD Parks by removing Scotch broom and daphnefrom Garry oak ecosystems, and monitoring and restoring species at risk plant populations (CRD Parks 2003).
  • The Nature Conservancy of Canada (NCC) has conducted shrub removal (Scotch broom and common snowberry) and established experimental plots at the Cowichan Garry Oak Preserve and at the deltoid balsamroot site in Campbell River (Ennis pers comm).

2.9 Socioeconomic Considerations

The species addressed in this recovery strategy do not have specific economic or social values, other than the historical, cultural and aesthetic values associated with intact Garry oak woodlands. The effects of implementing this recovery strategy are therefore low except on particular sites, and the extent of the affect will have a minimal area involved.

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 Garry oak woodlands 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 ecological 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 Garry oak woodlands,
  • directly damage or destroy an individual species at risk (such as through trampling or wheeled activities), or
  • modify or destroy Garry oak woodlands (such as through complete terra-forming).

Recovery actions could potentially affect the following socioeconomic sectors: recreational activities, private land development, parks operations and maintenance. The expected magnitude of these effects is expected to be low in almost all cases.

Garry oak woodlands 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 of Garry oak woodlands and their associated species at risk will require intelligent planning for any development, and determination of appropriate uses for sensitive locations. Managers of public lands such as parks may need to consider access and facilities management in order to maintain and improve Garry oak woodlands under their stewardship.

2.10 Statement of when Recovery Action Plan (RAP) will be completed

A Recovery Action Plan for Garry oak woodland species at risk has not yet been initiated. A draft recovery action plan will be completed by March 2010.

2.11 Evaluation and measures of success

Evaluation of the recovery objectives and approaches will largely be accomplished through routine monitoring of populations and habitat trends, with maintenance or increase in current population sizes, and extent and area of occurrences, being a minimum requirement for acceptable progress toward recovery goals. The Recovery Strategy will be reviewed after five years to evaluate the progress on recovery objectives and to identify additional approaches and other changes that may be required.

Additional performance measures that may be used to evaluate recovery progress include:

  • Formalization of critical habitat designations in the Recovery Action Plan
  • Knowledge gaps addressed
  • Level of proposed critical habitat protection achieved
  • Percentage of protected areas with species-specific management practices included in their management plans
  • Number of additional populations protected through land acquisition or stewardship agreements
  • Establishment of a research strategy to better understand invasive species biology and eradication
  • Number of sites with effective habitat restoration actions completed, including non-native species removal, and removal of shrubs and conifers where appropriate
  • Completed analysis of population sizes and trends at existing sites to determine whether augmentation is necessary
  • Completion of surveying and ranking of potential Garry oak woodland recovery sites
  • Designation of the five species under the provincial Wildlife Act as Species at Risk