Forked three-awned grass (Aristida basiramea) recovery strategy: chapter 2
- 2.1 Recovery feasibility
- 2.2 Recovery goal
- 2.3 Recovery objectives
- 2.4 Approaches to meet recovery objectives
- 2.5 Mitigation measures
- 2.6 Critical habitat
- 2.7 Evaluation
- 2.8 Development of action plans
Recovery of A. basiramea in Canada is determined to be feasible because the species meets all four necessary conditions (Environment Canada 2005), as described below.
- The presence of dense growth of A. basiramea in localized areas suggests that individuals are capable of reproducing at a rate sufficient to improve population sizes and potentially, population growth rate. Furthermore, the presence of adventive populations in the eastern United States indicates that the species is able to grow and survive even if the seeds arrive in only marginal dry, open terrain.
- The species’ habitat in Canada has been described as “dry open sand barrens, on low, sand ridges or dunes, located on post-glacial shorelines” (COSEWIC 2002). The availability of that type of habitat can be limited by overgrowth of vegetation and is assumed to be maintained by recurrent fires or drought. More habitat can be made suitable by creating open ground in sandy areas adjacent to existing populations.
- Significant threats to the species such as sand extraction, changes brought by vegetation succession, permanent habitat losses (through development), conifer plantations, and invasive species (COSEWIC 2002) can be effectively avoided or mitigated through (1) the use of management and stewardship actions to protect and improve habitat; and (2) research and monitoring to support conservation and management decisions.
- Many techniques exist that can contribute to the recovery of this species. While these techniques have not yet been tested on A. basiramea, they have proven effective in conservation of other annual plant species in similar habitats (see for example Pavlik 1993).
- The few populations of Aristida basiramea occurring in Canada form the northern limit of the species’ distribution in southern Ontario and Québec. The species is widely distributed in the United States where its status is secure in most states. However, in some of the U.S ‘outliers’, i.e. New York and New Hampshire, it is considered as S1 or S2 (Oldham 2002).
- There is no evidence that the distribution of the species has diminished or that the number of populations has declined in Canada due to direct or indirect human activities in recent history. However, at least one population has been greatly reduced by housing development in the past few years, and is on the verge of extirpation. Also, the species occurs in Canada as naturally disjunct populations believed to be relicts of past climates, or possibly related to migration of aboriginal peoples. This makes the species of conservation, cultural, and scientific interest.
- The species has shown an ability to colonize disturbed sites.
- There is no specific knowledge about the dynamics of the species’ populations, especially of the soil seed bank, so their long-term viability cannot be assessed.
The conditions stated above do not warrant actively extending its distribution range in Canada, but augmenting local populations may be needed.
The recovery goal for the species is therefore:
“To maintain self-sustaining populations of Aristida basiramea at all the sites where the species is of native origin in Canada.”
Even with good potential for mitigating threats, because habitat for A. basiramea is naturally extremely rare and fragmented, the species may still meet COSEWIC criteria for endangered or threatened species in 2012 when its status will be reassessed. However, it is hoped that the species will be downlisted to “special concern,” if there is evidence that recovery factors have combined to ensure the species' security. Criteria for this assessment could include recovery measures implemented with success, no significant loss in area of occupancy, and ideally, discoveries of a significant number of new occurrences. See section 2.7 Evaluation.
- A. basiramea persists in its natural habitat at the five known sites where the species is thought to be of natural originFootnote 2, with population sizes remaining viable for the next 10 years and beyond.
- Measures necessary to avoid and mitigate threats to the species and its habitat are identified and mitigation has begun by 2007. These would include a range of tools for consideration.
- Research and monitoring of a high scientific standard to document and assess habitat requirements, population trends and viability have started in at least two populations by 2007.
- Educational material necessary to foster good stewardship of the species and its habitat are prepared and distributed to target audience(s) by 2007.
The recommended approach to address threats to the species in Canada is to protect habitats, with site-specific protection measures. The range of tools to be considered include protective park zoning, acquisition, cooperative stewardship with private landowners, conservation easements, Habitat Floristique designation, and educational communications (Appendix 1).
The Beausoleil Island site in Georgian Bay Islands National Park is the only site with legal protection. Park management is currently (December, 2005) discussing the type of protective zoning and management to be put in place for the site to increase the protection for the species, and a proposal to rezone will be made through the Parks Canada Agency park management planning process. This rezoning will require public consultation (Andrew Promaine, pers. comm. 2005). A detailed census and maps of the population and supporting vegetation communities were completed in October 2005 and will serve as a benchmark for monitoring. Given the apparent slow pace of vegetation succession occurring on the site, this population of A. basiramea is likely to remain stable for the next 10 years without any intervention.
The Macey Lake site contains privately owned land as well as land in municipal jurisdiction. Part of the site is within a provincially significant Area of Natural and Scientific Interest (ANSI), the Macey Lake Bog ANSI, and is within 120 m of the Macey Lake Bog Provincially Significant Wetland (PSW) (COSEWIC, 2002, Hanna, 1984). The official plan for Tiny Township treats provincially significant ANSIs, PSWs, and the 120 metres adjacent to PSWs, as “Environmental Protection One.” Permitted uses on lands with this designation are limited to conservation and passive recreational uses. No buildings, structures, or any site alteration are permitted in this designation. The habitat of species designated Threatened or Endangered by COSEWIC and OMNR is also treated as Environmental Protection One. However agricultural use is not excluded (The Planning Partnership, 2000).
Cooperative work with the private landowners and the municipality to develop stewardship plans is the preferred option for this site.
At Anten Mills, one of the three subpopulations is under a conservation easement held by the Nottawasaga Valley Conservation Authority (NVCA). The landowner is a co-signatory of the Conservation Easement Agreement on the property.
The easement prohibits subdivision of land, placement or construction of buildings or structures of any kind, placement or dumping of fill or refuse, grading or altering the land, or harvesting or removal of vegetation except by NVCA in consultation with MNR (David Featherstone, pers. comm. 2005). The landowner is aware of the easement, but there has been little contact between NVCA and the landowner. The easement covers part of an open area between the subdivision and a municipally-owned recreational trail. It is uncertain whether the easement adequately protects the immediate habitat of the sub-population, which may be used by anyone in the subdivision and possibly by users of the adjacent trail. The recommended approach for this sub-population is active stewardship, including informative signage.
From a site inspection in October 2005, it is believed that the other two subpopulations at Anten Mills (which occurred in the area that was degraded during construction) are almost certainly extirpated (Allen and Nantel 2005). In the case that there is any habitat intact, the recommended approach is cooperative stewardship and possibly conservation easements with private landowners under the direction of NVCA. Reintroduction of the species to other proximal areas should also be considered.
Christian Island is part of the Beausoleil First Nation reserve. The accomplishment of the Beausoleil First Nation in protecting and preserving the natural values of their lands should be recognized since their three islands support some of the best remaining examples of natural habitat on the southern Georgian Bay coast (Sharp and Associates Inc. 2003).
In Spring 2005, Beausoleil First Nation Chief and Band Council enacted a Band Council Resolution to protect the parts of the A. basiramea population which are on community-owned land (Melvin King, pers. comm. 2005). On May 9th 2006 Chief and Council enacted another Band Council Resolution approving this Recovery Strategy. They also have planned a complete biodiversity inventory of all reserve land (King 2005).
A detailed survey of A. basiramea on the island was completed in September 2005 (Jones 2005). It indicates that the main threats to the species on Christian Island are the successional closure of its open habitat, and the filling-in of the gaps between grass tufts with other species, especially the weeds mouse-ear hawkweed (Hieracium pilosella) and sheep sorrel (Rumex acetosella). There is probably some level of threat to the patches of the species that are around some houses and in some open spaces in the village. The species is not found at many houses or driveways, but the open areas where it is found are places that people may want to use in the future for activities such as construction, storage of vehicles, boats, stacking of firewood. Since A. basiramea remains present in the village despite years of human use, this threat currently seems low, and it will be difficult to separate the level of activity which is a threat, from the disturbance level which benefits the dispersal and growth of the species.
In the past, the site of one subpopulation at Christian Island was burned annually when band members cleaned up the baseball diamond in the spring. If band members are agreeable to burning, a stewardship plan which continues the annual burning in the surrounding habitat is recommended, especially as this would allow further research on the use of burning as a management tool. Areas for burns may need to be rotated to ensure that other species are not adversely impacted over the long term (e.g., insects, reptiles,).
The recommended approaches at Christian Island are:
- To continue to work cooperatively with Beausoleil First Nation Chief and Council on stewardship that makes sense for both the species and the community members.
- To foster stewardship by owners of Certificate of Possession lands, through outreach and dialogue.
- To respect any culturally sensitive sites when conducting field surveys or monitoring.
At Cazaville, two approaches are recommended. One is to give the site a designation (such as Habitat Floristique, under Québec’s provincial legislation) which would give the habitat some protection in the official land use plans of the three municipalities in the area. The second approach is to provide educational information to private landowners, and later to work with landowners on stewardship actions, including erecting barriers to ATVs and installing interpretive signage.
On Christian Island, a translocation experiment was done at the site of the new recreation centre. In May 2005, sod containing a known patch of A. basiramea that would have been lost was translocated about 150 metres away. During the summer, the translocated sod (with associated seed bank) sustained a large number of plants of A. basiramea that developed well, and were bearing seeds by September. The species’ adaptation to soil disturbance makes removal and reintroduction an appropriate mitigation measure when no other alternative exists and done at a small scale. The translocated patch at Christian Island will continue to be monitored.
Because the species grows on sand, the effort needed to maintain soil integrity for each plant during transportation, and the risk of decreasing survival rates, makes transplantation of individual seedlings and larger plants less appropriate. However, seed collection and seeding at another location would be a reasonable alternative to translocating sod and soil in emergency cases. (It should be stressed that translocation is for “emergency situations” only, and that recovery objectives for A basiramea work towards persistence in its natural sand barren habitat, and protection and management of such communities.)
Finally, creating open, bare, sandy ground adjacent to current populations may work as an emergency measure to promote species growth. On Christian Island, A. basiramea was more abundant in the newly disturbed ground next to the translocation than it was in the translocated plot itself.
Although some of the environmental characteristics of A. basiramea’s habitat are well documented, critical habitat for the species cannot be defined precisely enough at this time without further studies.
Habitat that is known to be occupied can be mapped relatively easily. However, because no habitat model for the species exists, it is currently impossible to accurately predict where suitable ‘potential habitat’ and ‘apparently unoccupied habitat’ (i.e., suitable sites that contain viable seed bank) might occur. Moreover, because the number of individuals that constitute a viable population is not known, the size and spatial configuration of habitat patches which could support such populations cannot be determined. Because of such important knowledge gaps, it is recommended that the species’ critical habitat be identified and delineated in future action plans, after the appropriate studies have been conducted.
In the interim, recovery planning for the species in Canada could consider the available knowledge summarized below.
The types of habitat where the species has been found so far are:
- Sandy barrens on relict dunes and shorelines from post-glacial lake/sea levels;
- Dry, open, un-shaded sandy areas with patches of bare ground exposed;
- Patches of sand and sandy verges of roads and trails through openings in woodlands and conifer plantations; and
- Sandy fallow fields and abandoned sand pits.
These habitats are usually dominated by poverty grass (Danthonia spicata), often with panic grass (Panicum acuminatum var. implicatum), ensheathed dropseed (Sporobolus cryptandrus) and sheep sorrel (Rumex acetosella).
Processes which maintain the openness of the area and the patches of bare ground are considered essential. A burning regime may be needed to clear debris and maintain prime sand barren conditions. Yearly burning has proven to be beneficial at Christian Island. However, it should be noted that very little is understood about the fire history, fire cycle, and the general dynamics of ecological processes in A. basiramea habitat. Until further study is done, the precise need for fire and other ecological processes cannot be defined.
In the absence of fire or other natural disturbance, anthropogenic intervention may be needed to maintain critical habitat. In some cases, human disturbance that clears ground and provides new bare sand has proved beneficial to this species. In parts of the Macey Lake site, plants have colonized disturbed ground adjacent to natural habitat, and at Cazaville, plants have colonized old sand quarries. At Anten Mills the species is present along margins of old tote roads and trails.
Unoccupied but suitable habitat patches are also important for population maintenance for several reasons. First, A. basiramea is an annual, and population sizes and even presence/absence may fluctuate from year to year. Consideration should be given to sand barrens where the species may disperse, or where it may be present in the ground as seed bank, even if there are no living plants. Second, the species’ preferred micro-habitat is an open sand substrate which can shift and blow, causing some natural movement of colonies (including loss and re-colonization) over a period of time. This means the species may move in and out of an area as conditions allow, but may not be present all the time. Finally, adjacent sandy habitat which may be overly vegetated (presently unsuitable) could be considered as potential habitat because it may become suitable through disturbance which creates bare ground (fire, blow-downs, etc.).
Therefore, critical habitat for recovery should include unoccupied sandy openings adjacent to current populations/sub populations and sandy areas with somewhat grown-in vegetation adjacent to current populations. Areas which are not included in the definition of Critical Habitat could become Critical Habitat if A. basiramea moves into them after a new disturbance.
Critical Habitat will be identified after completion of the schedules of studies below. Results of these studies will be shared with each jurisdiction responsible to produce an Action Plan as described under section 47 of the Species at Risk Act. The identification of Critical Habitat for Aristida in no way implies that such areas become “no touch” zones, where human use is not encouraged. Rather, some human activities may be entirely appropriate in the habitat, and in fact, in some cases, may be deemed necessary to perpetuate the desired site conditions.
Map suitable but apparently unoccupied habitat at Cazaville: Analyze previously mapped relict shorelines in SW Québec to locate areas where additional populations and potential habitat could exist; Survey these areas.
Studies on the role of fire and other ecological processes which maintain the openness of habitat will be part of future action plans.
Table 3 lists the recommended steps to achieve the recovery objectives.
|#||Priority||Obj. #||Broad Approach||Threats Addressed||Specific Steps||Anticipated Results|
|1||Urgent||II, I||Analysis||All||Assess threats and level of urgency at all sites||Action plans can target most urgent threats first|
|2||Urgent||III||Monitoring||All||Design and implement a monitoring program for all sites||Changes in populations are trackable; emergency intervention is possible|
|3||Urgent||III||Research||All||Complete studies to determine critical habitat||Establish legal protection for species and habitat|
|4||Urgent||IV||Protection||Limited habitat, Dumping of Garbage||Inform Municipality of Tiny Township of species presence||Maintain population|
|5||Urgent||I, II||Protect, Conserve and Recover Populations||All||Assess best options for protection, conservation and recovery of individuals and habitats for A. basiramea on a site by site (or subpopulation) basis||Appropriate agreements and protocols can be planned|
|6||Urgent||II, I||Protect, Conserve and Recover Populations||All||Evaluate how best to address concerns and mitigate threats at culturally significant sites, potential development sites, or sites with other identified threats||Site-appropriate solutions can be worked out|
|7||Urgent||II, I||Protect, Conserve and Recover Populations||All||Establish any necessary agreements, SARA permits or protocols to address these concerns||Necessary agreements and protocols in place for protection and recovery of the species|
|8||Urgent||I||Policy||Seccession||Apply protective park zoning to Beausoleil Island site||Enhanced management attention possible|
|9||Urgent||III, IV||Define target audience for stewardship discussion||All||Look up contact information for all Cazaville landowners||Contact with landowners becomes possible|
|10||Urgent||IV||Stewardship||Development Sand Extraction Dumping of Garbage ATV use Conifers Agriculture||Prepare informative materials for Cazaville landowners||Increased awareness of species and habitat; landowners become interested in stewardship|
|11||Urgent||II, I, IV||Stewardship||ATV use||Work with private landowners to erect barriers to ATV use by trespassers||Maintain habitat quality|
|12||Urgent||II||Policy and Legislation||Development Sand Extraction Conifers Agriculture||Designate the species as threatened in Québec||Legal protection for species; Steps 13 and 14 become possible|
|13||Urgent||I||Policy||Development Sand Extraction ATVs Dumping of Garbage Agriculture||In consultation with appropriate stakeholders, consider using an appropriate designation for Cazaville site such as Habitat Floristique or Natural Reserve on Private Land||Protection during the land use planning process|
|14||Urgent||IV, I||Policy||Development Sand Extraction Dumping of Garbage Agriculture||Consult and liaise with municipalities at Cazaville to assure protection of the species in official plans||Protection during the land use planning process|
|15||Urgent||IV||Stewardship||ATVs Dumping of Garbage Conifers Invasive spp.||Meet with landowner about stewardship of Anten Mills easement||Active stewardship visible to surrounding community|
|16||Urgent||III||Stewardship||ATVs Dumping of Garbage Conifers Invasive spp.||Assess whether any other subpopulations still exist at Anten Mills||Cooperative stewardship can be put in place|
|17||Urgent||I, III||Research, Knowledge gaps||Limited Habitat, Development (habitat loss)||Analyze mapped relict shoreline areas and survey these areas for other potential populations of A. basiramea||Distribution of A. basiramea and critical habitat better understood|
|18||Urgent||IV||Stewardship||ATV's, Dumping of Garbage||Contact utility companies about A. basiramea presence in corridors on Christian Island||Appropriate management can be put in place|
|19||Necessary||I||Management||Succession||Prepare management plans for Beausoleil Island site||Site managed to maintain habitat|
|20||Neccessary||II, I||Policy and Legislation||Development Sand Extraction Conifers||Legally regulate A. basirameaunder Endangered Species Act in Ontario||Legal protection for species and habitat|
|21||Neccessary||III, I||Research and Management||Limited Habitat Succession||Study fire history of sites and controlled burning as possible habitat improvement tool||Determine if burning may be needed|
|22||Neccessary||III, I||Research and Evaluation||All||Use monitoring data to determine if size of populations are changing||Results of recovery efforts known|
|23||Beneficial||III, II||Management||Conifer Plantations||Assess age of conifer plantations for possible harvest||Increased open habitat available|
- Once a monitoring program is in place (Objective III), a measurable criterion of recovery will be no significant decline in population size and no local extirpation (Objective I).
- Some policy-oriented forms of protection will be in place by 2008 (Objective I), including any of the following: legal regulation or listing of the species by the provinces of Québec and Ontario, recognition of species and supporting habitat in municipal level planning approvals, protective park zoning, Habitat Floristique or Natural Reserve on Private Land status for the Cazaville site (under Québec’s legislation), etc.
- Definition of critical habitat should be completed by 2008 (Objective III).
- There should have been some direct contact with all private landowners and at least the presence of the species and its habitat should be known to them, by 2007 (Objective IV).
- Threats to the populations and habitats have begun to be addressed in 2006 (Objective II).
- Research initiated and development, testing, and monitoring of draft protocols for high priority protection and recovery begun by 2008 (Objective III).
Because there are several jurisdictions involved, with different species at risk legislation, regulations, policies, and priorities, it is recommended that each jurisdiction prepare the following action plans under its respective legislation or program by June 2009, subject to the availability of funding or other required resources:
|Action Plan||Jurisdiction||Targeted Population(s) or Site(s)|
|1||Province of Ontario (Ministry of Natural Resources), Nottawasaga Valley Conservation Authority, Municipality of Tiny Township||Anten Mills
|2||Province of Québec (Ministère du Développement durable, de l’Environnement et des Parcs)||Cazaville|
|3||Parks Canada Agency||Beausoleil Island|
|4||Beausoleil First Nation Environment Canada||Christian Island|
Recovery Implementation Groups (RIGs) could be formed and given the task of implementing action plans, with the Aristida Recovery Team playing an advisory role and providing a forum for sharing knowledge and experience.
Recovery actions already underway or completed are listed in Appendix 1.
- Date modified: