Spoon-leaved Moss (Bryoandersonia Illecebra)
All Canadian specimens of Spoon-leaved Moss are female, and no sporophytes have ever been documented. However, the Canadian population cannot be surveyed in its entirety for male plants because sex determination in bryophytes requires destructive sampling, and the absence of sporophytes in collections does not definitively confirm the inability of Canadian populations to produce them. With respect to asexual reproduction, extant colonies are presumably capable of expansion within their respective sites, and plant fragments are probably capable of dispersal over short distances, particularly with the assistance of water or other local vectors. The extent to which vegetative propagation might be able to improve growth rate or abundance depends on factors such as natural rates and patterns of senescence, extent of available suitable habitat, and current trend in population size, which have yet to be documented. Minimum viable population is not known for Spoon-leaved Moss, or for most bryophytes (if any), and modification of commonly-used methods (e.g. Menges 1990, 1991) would be required before it could be defined.
Without temporal demographic data for Spoon-leaved Moss or data pinpointing reasons for the species’ limitation and its potential decline, it is not clear that protecting current populations will be sufficient to ensure long-term persistence. Spoon-leaved Moss has been known from one or two sites since the early 1980’s, which suggests that persistence is possible without intervention. Intervention-based attempts to recover rare bryophyte populations, such as transplanting colonies, plants, fragments, or spores to manipulate gender ratios or augment populations, are not known in North America (but note that peatland restoration involves re-introducing moss diaspores (e.g. Rochefort & Bastien 1998, Rochefort et al. 2003)). In Europe, however, ex-situ conservation and re-introduction have been applied to several rare bryophytes (e.g. Kooijman & Beltman 1994, UK Biodiversity Action Plan 2005). Their potential for success in the current context cannot be predicted, but this recovery strategy provides an important opportunity for research that may serve future attempts to recover rare bryophyte species. A wide body of literature exists describing bryophyte plant and diaspore propagation for experimental purposes (e.g. references cited in Kallio & Saarnio 1986, Wiklund & Rydin 2004, Cleavitt 2005), and can provide important background information to help increase the chances of success.
Additional considerations for recovery feasibility include the existence of sufficient habitat to support the species, and the ability to reduce threats to the species or its habitat. These criteria appear to be met for Spoon-leaved Moss, as shown by the species’ persistence in the region despite dense human activity, the protective designations placed on all sites where it occurs, and observations that direct human disturbance of the sites is unlikely (R. Gould, personal communication).
In brief, recovery of Spoon-leaved Moss is currently considered to be feasible. This conclusion will be reviewed in the context of future research findings.
Recovery Goal, objectives and corresponding approaches
The goal of this recovery strategy is to conserve existing populations of Spoon-leaved Moss in the long term and, if possible, to restore the species’ long-term stability and self-sustainability in Ontario by increasing the size of existing populations and/or increasing the number of known occurrences. Target population number and size are therefore set at the minimum of current levels for each of the three sites of occurrence in 2005, pending research to determine the feasibility of increased targets.
Without specific demographic information with which to confirm the trends in the Canadian population or to define the minimum viable population, and without a firm understanding of key factors limiting Spoon-leaved Moss, setting realistic, relevant recovery objectives and performance measures is an uncertain process reflecting the best interpretation of available data (Menges 1991, Schemske et al. 1994, Nantel & Gagnon 1999). However, this does not preclude the development of recovery targets or commencement of activities. It is also important to recognize the distinction between rarity, which may be normal for Spoon-leaved Moss as a peripheral species in Canada, and endangerment (e.g. Morse 1996), which the recovery process is designed to reverse. Threat management can only increase the species’ status within the bounds of its naturally limited capacity.
With this in mind, the following objectives are to be addressed within the next five years in support of the recovery goal.
- Monitor habitat to detect potential threats at all three sites of occurrence annually (or more frequently) and address causal agents.
- Maintain or increase current population size (measured as area occupied by moss and number of colonies) at each site of occurrence by protecting plants and critical habitat.
- Identify broad-scale conservation initiatives in the Carolinean life zone relevant to the Spoon-leaved Moss and identify activities on which to collaborate.
- Increase the knowledge base with respect to species demography, biology, distribution, abundance, habitat requirements, critical habitat, threats, transplant/introduction techniques, and/or feasibility of recovery to the extent that long-term sustainability is confirmed or that:
4.1. Recovery goals and activities necessary for long term persistence of Spoon-leaved Moss populations, as outlined in this document, are supported or can be justifiably modified,
4.2. The necessity/feasibility of restoring population size and/or number can be assessed.
Broad strategy to be taken to address threats
Threats of habitat degradation and population decline must be addressed through the broad strategies of monitoring, management and research (Table 3). All activities (Table 3) involve careful on-going planning, re-evaluation and communication throughout the recovery process. They take into consideration the three-step approach advocated by Schemske et al. (1994) for developing efficient recovery strategies: 1) determine the biological status (increasing, decreasing, or stable) of the species through demographic research, 2) identify the life history stages with the greatest effect on biological status, 3) explore the biological reasons for variation in those life history stages. These steps serve to prioritize research and, subsequently, recovery activities according to factors that are of greatest relevance to the species’ persistence.
There is no detailed demographic information on Spoon-leaved Moss, and collecting these data is given first priority (along with threat monitoring) among research and recovery activities. It seems doubtful, however, that sufficient data can be gained from Canadian populations, given their limited number and extent and their long-lived perennial life strategy, to apply population modeling. Monitoring of core (US) populations (Nantel & Gagnon 1999), which are more numerous and thus more conducive to demographic modeling, may help to identify vulnerable life history stages in the species, and the degree to which populations north of the international border are characteristic of the species in general. In the meantime, however, casual observation suggests that important demographic components of the species (male plants, reproducing individuals) are absent or rare in Canada. At least one population has persisted for over twenty years, but overall population decline is inferred. In the absence of hard demographic evidence, it seems most likely that barriers to reproduction (and therefore dispersal) may be greater than those to growth and survivorship, and the proposed research reflects this priority. Investigating these barriers (e.g. through transplant trials, controlled growth experiments) will reveal the human activities likely to affect reproductive ability, and the feasibility and methods of reducing their limiting effect.
Although the results of genetic studies are difficult to relate directly to population viability or demographic ‘fitness’ of a plant population (Ellstrand & Elam 1993, Schemske et al. 1994), they are proposed here as a means of researching dispersal distances and paths, as well as gender, within the Canadian population and between Canadian and US populations. Despite the rationale presented above, reproductive limitation may not be the key limiting factor for Spoon-leaved Moss in Canada. Thus, although studies of factors limiting establishment and growth are not given first priority at this time, all research of ecological requirements (see section 2.3 – data gaps) is encouraged for its potential value in determining current limiting factors (Schemske et al. 1994), or in facilitating re-introduction if it becomes necessary. Although full scientific certainty may never be achieved, measures should be set in place immediately with the understanding that the broad strategy is dynamic and that the results of monitoring, management and research will continually supply information for ongoing development of the recovery strategy.
|Priority||Obj. No.||Broad Approach / Strategy||Threats addressed||Specific Steps||Outcomes or Deliverables (identify measurable targets)|
|U||1,2,3,4||Communication and Co-ordination||All|
· Identify partner organizations (e.g. Ministry of Natural Resources, Niagara Peninsula Conservation Authority and relevant affiliates/associates) in the implementation and facilitation of recovery strategy; identify lead co-ordinating agency; identify land users/stakeholders
· Develop and implement communication strategy among partner organizations (including methods and frequency of activity reports, data submission, and strategy re-evaluation); Develop and implement strategy for communicating with land users/stakeholders with respect to recovery activities as required
· Partner with broad conservation initiatives (e.g. Carolinian Canada programs, Carolinian Canada Woodland Plant Recovery Team) targeting general threats such as habitat fragmentation, atmospheric pollution, acid rain, by restoring ecological integrity of southern Ontario as well as land use planners such as provincial/regional/municipal governments to encourage both direct habitat protection and indirect (e.g. changes to hydrology).
· Submit all new data to the Ontario Natural Heritage Information Centre in a timely manner
· Recovery activities are consistent and co-ordinated
· Data are pooled and evaluated regularly
· Land-users and stakeholder activities are compatible with recovery activities
· Maximize availability of resources for recovery and efficiency of resource use
· Develop and implement monitoring protocol to detect human and natural threats at each known site of occurrence (adding sites if they are discovered), especially those to which Spoon-leaved Moss is particularly vulnerable as described in this report
· Monitor sites to assess the effects of any management actions
|· Annual summary of threat monitoring results (description, magnitude, action initiated) and mitigation efforts by site|
· Develop and implement monitoring protocol for Spoon-leaved Moss distribution / abundance / sporophyte occurrence (census) at each site (adding sites and colonies if they are discovered)
· Correlate monitoring results with threat monitoring and management activities
· Annual summary of population monitoring results (distribution and abundance) by site
· Documentation of local population dynamics
· Develop population-specific management plans to reduce / remove threats to populations and to critical habitat as it is incrementally identified (e.g. trampling, removal of overstory and /or ground vegetation by humans or wildlife)
· Adapt management plan annually (or more frequently) to take new information into account
· Identify criteria with respect to rate of population decline (size/distribution) that would trigger immediate re-evaluation of recovery priorities and activities, and incorporate them into the management plans
· Incorporate management plans into existing management documents for the protected areas in which the sites occur
· Management plans developed and implemented for all populations and their critical habitat
· Population-specific management plans fully integrated into site management plans
· Annual summary of management activities and outcomes
· Habitat and populations maintained or increased at managed sites
Habitat Destruction and Fragmentation
· Develop, prioritize, and initiate a research schedule to:
o Implement research schedule to identify critical habitat
o Determine demographic status and trends in Canada and the nearby US
o Pinpoint factors affecting reproduction and dispersal ability in Canada
o Explore reproduction and dispersal patterns / ability through genetic relationships
o Characterize species’ biology and ecology at all life history stages in Canada and the adjacent northern US (especially New York, Michigan)
o Modify Minimum Viable Population methods and determine MVP for Spoon-leaved Moss
o Research re-introduction attempts in European jurisdictions and experimental transplant methods; initiate trials (e.g. transplant, spore plot) with potential source populations and target sites (e.g. historical sites) in Canada
· Incorporate research findings into population-specific management plans
· Incremental critical habitat identification progresses
· Detailed distribution and abundance of Spoon-leaved Moss among and within Canadian populations, and their temporal dynamics, are used to identify limiting life history stages and place Canadian populations in context of general species patterns
· Factors limiting distribution/abundance are confirmed or discounted
· Spoon-leaved Moss biology and needs are characterized
· Feasibility and potential strategies of (re)introduction to restore or augment Canadian population are justified and documented when they become relevant
· Recovery potential is determined
Habitat Destruction and Fragmentation
· Evaluate need for (re)introduction to restore Canadian population based on research and monitoring results
· Develop (re)introduction strategy according to research results and incorporate into population-specific management plans as required
|· Canadian population is restored to more stable, self-sustainable levels|
Effects on other species
No immediate negative impacts on non-target species, natural communities or ecological processes are anticipated to result from the proposed recovery activities. Generally speaking, the protection of Carolinian habitat from degradation will benefit all species at affected sites.
Research and monitoring activities that take place at Spoon-leaved Moss sites should be structured in such a way that neither site access nor the activities themselves significantly modify or damage the site or its resident biota (including Spoon-leaved Moss), and the effects of recovery activities should themselves be monitored to ensure that this is the case. The need to collect Spoon-leaved Moss, for genetic studies for example, will be carefully evaluated and regulated so as to minimize impact on the populations.
Performance measures for evaluating success in meeting the stated recovery objectives will include the extent to which each objective has been met, using the broad strategies identified above.
Performance measures of biological effect of recovery activities:
· Status and condition of known populations
- Population number, colony number, and area occupied at minimum of 2005 level
- National status maintained or upgraded at next assessment (2013)
- Stable or increasing provincial and local populations in terms of number of localities and local abundance
Performance measures of recovery activity process:
· Establishment and ongoing implementation of threat monitoring
- Annual monitoring and documentation complete
- Management and research plans reflect results of threat monitoring
· Establishment and ongoing implementation of population monitoring
- Temporal trend or fluctuation (or lack thereof) in local population size (colony number, area occupied) has been described
- Annual monitoring and documentation complete
- Management and research plans reflect results of population monitoring
· Establishment and ongoing implementation of research
- Critical habitat identification has progressed beyond 2005 level
- Recovery feasibility is established with respect to at least one additional criterion
- Additional populations found are mapped and incorporated into the recovery program and areas searched are fully documented
- Identification of limiting factors has progressed beyond 2005 level
- Species biology and ecology can be described in greater detail than in 2005
- Research results are incorporated into updated research schedule
- The necessity of and approaches to re-introduction has been evaluated in preparation for incorporation into management plans
- Published research articles reflect research results
· Establishment and ongoing implementation of communication strategy
- Spoon-leaved Moss management activities incorporated into all relevant management/planning documents
- All land use compatible with recovery activities
· Establishment and ongoing implementation of management plans
- Management plans and activities reflect most recent available data from within and outside the recovery program
As stated above, although recovery activities should commence immediately based on the available information, the recovery objectives and activities are designed in this recovery strategy to undergo regular revision based on new information arising from research and monitoring. Four main knowledge gaps have been suggested throughout this document (Table 4) and are addressed in the preceding research schedules.
|Gap||Value of Research|
|Demography (rates of population and metapopulation growth/decline, gender ratio, sporophyte production) in Canada and the nearby US||As discussed in section 2.2.3, demographic data are key to establishing status and to revealing life history stages with the greatest effect on status. They are also vital to the identification of critical habitat (section 1.4.1). Routine (annual, if possible) census of each Canadian population, and of northern US populations, is recommended, as is the development of minimum viability population methods for Spoon-leaved Moss (research in the US is necessary to inform recovery in Canada). Vulnerability to stochastic events may also be partly revealed through demographic studies.|
|Dispersal ability of sexual and asexual diaspores||As outlined in sections 1.2 and 2.2.3, dispersal ability may be a critical limiting factor for Spoon-leaved Moss, in view of the apparent rarity of sporophyte production. Other approaches to determining dispersal limitation may be to introduce plants or diaspores to suitable habitat and cross-reference results with propagule viability to exclude establishment/habitat limitation. Dispersal ability may also be inferred from characters such as spore size or viability after storage (Cleavitt 2002, references in Cleavitt 2005). Genetic data could also help to reveal the species’ local and regional reproductive and dispersal patterns.|
|Ecological preference / tolerance associated with each life history stage (reproduction, dispersal, establishment, growth)||It is emphasized throughout this report that very little is known about the biology or ecology (e.g. substrate composition and chemistry; water chemistry; moisture, temperature, & light regimes; neighbour effects; overstory vegetation) of Spoon-leaved Moss. Regional, local, and micro-habitat scale preferences and tolerances should be explored, in both Ontario and in the northern US, where the species is more common and available for study. These studies would both provide information on the species as a whole and reveal ecological peculiarities of peripheral populations. It would also help to reveal the relative significance of potential threats.|
|(Re)introduction feasibility and methods||If it becomes necessary to consider intervention (introduction of plants or propagules) to augment populations or gender ratios in Canada, as mentioned in sections 1.2, 2.1 and 2.2, the feasibility, source populations, target sites, and methods of these activities will need to be established. This requires full exploration of moss re-introduction literature (mainly in Europe) and field trials. Genetic differences between Canadian and US populations could affect the sexual or ecological compatibility of introduced plants (Barrett & Kohn 1991, Kutner & Morse 1996, Helenurm 1998).|
Recommended Approach for Recovery
It has already been emphasized that recovery goals and activities for Spoon-leaved Moss should be incorporated into the management plans of the organizations (Ontario Ministry of Natural Resources, Niagara Peninsula Conservation Authority, Ontario Parks) that own and manage the land on which the species resides. No recovery strategies for individual species currently overlap with that of Spoon-leaved Moss, but there may be other opportunities for integrating species-specific recovery into other recovery or conservation efforts. For example, the plight of Carolinian species in southern Ontario is the object of considerable, well-publicized concern, and research and recovery activities have been initiated on many scales. The accessibility of the recovery goal for Spoon-leaved Moss, as for all rare Carolinian species, will be affected by the success of management activities directed to preserving other Carolinian species and to restoring ecological integrity to the landscape of southern Ontario (e.g. Ambrose & Kirk 2004). Consultation with the Carolinian Woodland Plant Recovery Team, which isattempting to address the ecosystem approach to recovery of Carolinian woodland habitat, and the associateddraft recovery strategy (in preparation) would also be productive.
Some of the research recommended in this strategy involves monitoring or measuring populations in the United States. Cross-border initiatives such the Canada-US Framework for Co-operation in identifying and recovering shared species at risk (Environment Canada 2001) highlight the potential for data exchange and resource sharing with respect to rare plants. While Spoon-leaved Moss is not rare in the United States, opportunities for the Framework or other programs to facilitate co-operation should be explored. For example, the genetic or adaptive features of Canada’s peripheral populations may be of conservation significance in the global context.
Statement of When One or More Action Plans in Relation to the Recovery Strategy Will Be Completed
In the absence of a recovery team for Spoon-leaved Moss, a Recovery Implementation Group will need to be formed to develop an Action Plan and implement the recovery activities. It is suggested that an Action Plan to implement the broad strategies identified in this recovery strategy be developed by 2008.
- Date Modified: