Cucumber Tree

Introduction

This chapter provides a review of progress toward protection and recovery of Cucumber Tree in Ontario from 2007 to 2015.

Species information

Cucumber Tree (Magnolia acuminata) is a forest species that can grow up to 30 metres in height. The species has large, toothless leaves that can be 10 to 24 centimetres long and 5 to 12 centimetres wide. Mature trees have grayish-brown bark with scaly ridges. In early summer the species grows large greenish-yellow flowers which mature into a red fruit with bright scarlet-orange seeds by late summer.

Cucumber Tree is the only magnolia species native to Canada, and grows in two regions of Ontario: the Regional Municipality of Niagara and Norfolk County. In Ontario, it generally exists in moist, well drained, deciduous or mixed upland forests with alternating hills and lowlands where canopy cover is partially open.

Cucumber Tree faces several threats to its survival and recovery. The most significant threat is forest clearing and the associated effects of habitat fragmentation. Populations of the species in Ontario are isolated due to habitat fragmentation which makes cross-pollination and seed dispersal difficult. Barriers to pollination and dispersal limit the species' ability to exchange genes, resulting in lower genetic diversity and limitations on the ability to adapt to change.

The survival and recovery of Cucumber Tree is also influenced by the species' biology. One of the main limiting factors for Cucumber Tree reproduction is its inability to disperse its seeds. Cucumber Trees most likely rely on birds to disperse their seeds, but the bird species responsible for dispersal are not known. Cucumber Tree is also limited by its need for small openings in the forest canopy for seedlings to grow effectively. The combined threat of habitat fragmentation and limitations in species biology influences the ability of Cucumber Tree to recover.

Cucumber Tree is listed as endangered at both the provincial (Species at Risk in Ontario List) and federal (Schedule 1 under the Species at Risk Act) levels. Globally, it is considered to be secure.

Provincial status

The Cucumber Tree was regulated under the previous Endangered Species Act and has been listed as endangered since 1987. Under the Endangered Species Act, 2007 (ESA or "the Act"), Cucumber Tree retained its status as endangered. The Committee on the Status of Species at Risk in Ontario (COSSARO) assessed the Cucumber Tree in 2010, and the species maintained its status as endangered on the Species at Risk in Ontario List. In future assessments, COSSARO may consider information gained through protection and recovery actions regarding the species' threats and trends in population and distribution.

Species and habitat protection

Protecting Cucumber Tree and its habitat are key components in the implementation of the ESA, and continue to be government-led actions, as identified in the government response statement. As a species that was regulated under the previous Endangered Species Act, Cucumber Tree has received species and habitat protection since 1987. At that time, the regulation was limited to specific locations for the species in Norfolk County and Niagara Regional Municipality. In 2005, the protection changed to apply to all wild-grown native-origin Cucumber Trees in Ontario, due to the discovery of several new locations for the species since 1987.

As an endangered species, Cucumber Tree has been protected from being killed, harmed, harassed, captured or taken under the ESA since it came into force in 2008. In addition, its habitat has been protected from being damaged or destroyed since 2008. Habitat protection under the ESA for Cucumber Tree is based on the general habitat definition in the Act, as the ESA does not require a habitat regulation to be developed for transition species ^{footnote 1[1]}.

Any person who negatively impacts Cucumber Tree or its habitat without prior authorization may be prosecuted under the ESA.

As a species that was regulated under the previous Endangered Species Act, Cucumber Tree has received species and habitat protection since 1987. The species is currently protected from being killed, harmed, harassed, captured or taken under the ESA.

In addition, the habitat of Cucumber Tree is currently protected from being damaged or destroyed based on the general habitat definition in the ESA.

Recovery strategy

A recovery strategy for Cucumber Tree was published on September 10, 2010, which was in advance of the timeframe required by the ESA. Recovery strategies are advice to government and represent the best available scientific knowledge. The strategy identifies Cucumber Tree habitat needs and the threats that it faces, while recommending objectives and approaches for protecting and recovering the species. The recovery strategy also includes recommendations on the areas of habitat to be considered in the development of a habitat regulation.

Government response statement

The Ministry published the government response statement (GRS) for Cucumber Tree on June 15, 2011, which was within the timeframe required by the ESA. The GRS is government policy that contains the Government of Ontario’s goal for the recovery of Cucumber Tree.

To help achieve this goal, the government leads and supports recovery actions identified in the GRS. Common actions for the government to lead as it works toward achieving a species' recovery goal are provided in section 2.5 of the Species at Risk Program Status (2008-2015). The GRS for Cucumber Tree also lists eight actions the Ministry supports others to undertake for the species. These government-supported actions fall under the objectives identified in the GRS, which are:

• Protect and manage existing natural populations and their habitats;
• Enhance the ability of populations to be self-sustaining by restoring habitat connectivity;
• Improve understanding of this species' biology and ecology; and
• Increase public awareness of the Cucumber Tree and the protection of its habitat.

Government funded projects

An important government-led action in the GRS for Cucumber Tree is to support partners to undertake activities to protect and recover the species. Through the Species at Risk Stewardship Fund the Ministry has supported a total of seven projects ($167,866) designed to contribute to the protection and recovery of Cucumber Tree. One of these projects ($7,600) focused exclusively on the species, while the other six projects ($160,266) focused on multiple species at risk, including Cucumber Tree. As well, the partner focusing exclusively on Cucumber Tree was successful in securing additional funding and in-kind support ($20,300) from other sources, as did partners with projects designed to benefit multiple species at risk ($428,781). These amounts include additional funding and in-kind support in the form of time and expertise provided by volunteers.

Stewardship partners reported that provincial funding helped them to secure in-kind support by involving four individuals who volunteered 120 hours of their time toward protection and recovery activities that focused exclusively on Cucumber Tree, which has an estimated value of $4,800. As well, a total of 477 individuals volunteered 4,582 hours of their time toward protection and recovery activities for multiple species at risk, which has an estimated value of $119,610. Stewardship partners reported providing ecosystem-based outreach on multiple species to 1,125 individuals.

The Ministry also supports partners in conducting research that addresses important knowledge gaps for species at risk. Through the Species at Risk Research Fund for Ontario and the Species at Risk Stewardship Fund, the Ministry provided support to Trent University to assist with genetic research on Cucumber Tree.

The remainder of this section highlights work supported through the Species at Risk Stewardship Fund, Species at Risk Research Fund, Conservation Land Tax Incentive Program, and Managed Forest Tax Incentive Program and their corresponding government-supported recovery actions.

To support the GRS action to cooperate with existing initiatives to connect and expand forest fragments to increase potential suitable habitat for Cucumber Tree, a stewardship partner provided woodlot owners with aerial photographs to promote knowledge on the importance of woodlot connectivity for species at risk, including Cucumber Tree. The partner examined an existing database of woodlot owners to identify woodlands with species at risk present on the landscape, and then distributed aerial photographs to landowners. This outreach and awareness work supports the private woodlot owners association’s existing initiatives to promote the conservation of species at risk trees located on private lands. This is an important first step toward identifying opportunities to address the GRS action identified above.

The same project supported a high priority GRS action to promote forest management practices that encourage natural recruitment of the Cucumber Tree, as well as the GRS action to develop and promote information to various sectors to increase awareness and promote the protection and recovery of Cucumber Tree. The partner worked with government, the forest industry, species experts and private landowners to develop best management practices (BMPs) for woodland species at risk, including Cucumber Tree. Using information gathered from this collaboration, recommendations on how to manage woodlands to protect and promote woodland species at risk were provided to private woodlot owners through a newly-launched species at risk web portal. This portal also includes compiled information on Cucumber Tree, including threats to the species, conservation actions, occurrence submissions and a forum to connect with resource experts and other woodlot owners. To address the second GRS action, a series of species information workshops and tours were hosted with participation from private landowners and the forest industry. These activities assisted with species at risk identification, submission of occurrence details, maintaining or creating habitat and monitoring forest health.

The Hamilton Naturalist Club supported the GRS action to increase awareness of the protection and recovery of Cucumber Tree by educating volunteers on how to monitor the species as well as other species at risk. The stewardship partner first gained valuable experience in monitoring the health of endangered species with the help of support from the Species at Risk Stewardship Fund. The partner was able to transfer these skills to volunteers to increase knowledge and understanding of the location, health and abundance of other at-risk species. Monitoring activities by this group led to the discovery of additional Cucumber Tree saplings growing within dense vegetation. University student volunteers also helped to remove the competing vegetation and further protect the trees from disturbance (e.g., deer browse and rubbing). These efforts have proven to be effective as demonstrated by ongoing monitoring of the trees.

Budd et al. (2015) investigated conservation genetics of the Cucumber Tree at the northern edge of the species' range by assessing patterns of genetic diversity and differentiation within and among Canadian populations. Additional samples (e.g., leaves) from Cucumber Trees in the United States were obtained in order to compare genetic composition of the Canadian populations with those from the more central distribution of the species' population. Researchers found that genetic diversity in mature trees in Ontario is similar to that in the United States population of Cucumber Tree. Another important finding by Budd et al. (2015) demonstrates that there is lower diversity in seedlings than that of mature trees in Ontario. This suggests that in recent time periods there have been relatively low levels of gene flow among the Canadian populations. Researchers explain that without intervention in a fragmented landscape, the species would likely become increasingly isolated and less genetically diverse. Important data and increased knowledge gathered as part of this research contributed progress toward the genetic portion of the GRS action to conduct detailed pollination, demographic and seed dispersal studies and determine the genetic composition of Cucumber Tree populations.

Species at Risk Stewardship Fund

• 
  $7,600

  for Cucumber Tree exclusively

• 
  $160,266

  for multi-species projects that included Cucumber Tree

• 
  $449,081

  in additional funding and in-kind support

• 
  7

  projects included the Cucumber Tree

• 
  481

  volunteers

• 
  4,702

  volunteer hours

• 
  1,125

  people received outreach

Efforts to minimize adverse effects on Cucumber Tree

Supporting partners through permits and their associated conditions, is an important government-led action. One permit has been issued for Cucumber Tree since the species has been protected under the ESA. This protection and recovery permit (i.e., 17(2)(b) permit) was issued for activities associated with a conservation genetics study of the species. 'Protection or recovery permits' are issued if the purpose of the activity is to assist the protection or recovery of a species at risk. One activity that may affect Cucumber Tree or its habitat has been registered for under 'Threats to health and safety, not imminent' (section 23.18) of Ontario Regulation 242/08 under the ESA, and includes work associated with rehabilitating a culvert. This registration requires the registered individual to comply with all conditions of the regulation, such as:

• Ceasing the activity if a person encounters a Cucumber Tree to create a protective zone around the species, and continue the activity in a manner that does not impair the ability of the species to carry out its life processes;
• Having an expert on the species develop a mitigation plan for the activity and implementing the actions outlined in the mitigation plan to minimize adverse effects of the activity;
• Reporting observations of the species to the Ministry using the Natural Heritage Information Centre Rare Species Reporting Form within three months.

Occurrences of Cucumber Tree in Ontario

9.1 Natural Heritage Information Centre (NHIC)

Cucumber Tree is found only in two very restricted areas in southwestern Ontario. Within these areas, the total provincial population consists of approximately 200 trees with many sites having only a few mature individuals.

Since 2008, when Cucumber Tree became protected under the ESA, the Ministry has received approximately 111 records of the species. These records are based on observations between 1904 and 2015 and come from a variety of sources. Records submitted have helped to redefine where the species is known and has been known to occur and have provided additional information on the species' habitat and threats. Thirteen populations ^{footnote 1[1]} of Cucumber Tree have been documented in Ontario, with seven populations classified as extant (i.e., observed within the past 20 years), one population classified as historical ^{footnote 2[2]} and five populations classified as extirpated (i.e., no longer in existence). No new populations have been found since 2008, when Cucumber Tree first became protected under the ESA. However, due to our increase in knowledge, one population previously thought to be extirpated and two populations previously thought to be historical are now classified as extant. Conversely, based on searches conducted prior to the ESA coming into force, one population of Cucumber Tree that was previously considered extant is now considered extirpated.

Everyone is encouraged, or may be required by an authorization or approval, to submit observations of the Cucumber Tree, as well as every other species at risk, to the Ministry’s Natural Heritage Information Centre for incorporation into the provincial record of observations.

Summary of progress towards meeting the recovery goal

Summary of progress

Progress has been made toward all government-led actions and the majority of government-supported actions outlined in the GRS for Cucumber Tree. The Government of Ontario has directly undertaken actions to:

• Encourage submission of Cucumber Tree data to the Natural Heritage Information Centre;
• Protect the species and its habitat through the ESA;
• Support partners to undertake activities to protect and recover the species;
• Establish and communicate annual priority actions for support;
• Educate other agencies and planning authorities on the requirement to consider the protection of the species and its habitat; and
• Undertake communications and outreach to increase public awareness of species at risk in Ontario.

Government-supported actions are organized under over-arching recovery objectives. Progress has been made toward the majority of the government-supported recovery objectives and five of the associated actions that are identified in the GRS for Cucumber Tree.

Under the objective to protect and manage existing natural populations and their habitats, progress has been made toward two of the three actions:

• Encourage stewardship of Cucumber Trees, including landowner participation in the Conservation Land Tax Incentive Program and the Managed Forest Tax Incentive Program (Action No. 1; High Priority); and
• Promote forest management practices that encourage natural recruitment of the Cucumber Tree (Action No. 2; High Priority).

The first action was implemented through landowner participation in the Conservation Land Tax Incentive Program and Managed Forest Tax Incentive Program which provide stewardship for Cucumber Tree, whereas a project supported by the Species at Risk Stewardship Fund in which a partner worked with various forest industry and species experts to develop and deliver best management practices for woodland species at risk supported progress toward the second action.

Under the objective to enhance the ability of populations to be self-sustaining by restoring habitat connectivity, initial progress has been made toward one of the two actions:

• Co-operate with existing initiatives to connect and expand forest fragments to increase potential suitable habitat (Action No. 5)

Important first steps toward addressing this action were implemented through a project supported by the Species at Risk Stewardship Fund in which a partner worked with woodlot owners to identify, monitor and manage or increase habitat on their lands for woodland species at risk, including Cucumber Tree.

Under the objective to improve understanding of this species' biology and ecology, initial progress has been made toward one of the two actions:

• Conduct detailed pollination, demographic and seed dispersal studies and determine the genetic composition of populations (Action No. 6).

Collectively, portions of the action were implemented through projects supported by the Species at Risk Stewardship Fund and the Species at Risk Research Fund in which a researcher examined the genetic composition of Ontario Cucumber Trees with one another and with those distributed in the central United States.

Under the objective to increase public awareness of Cucumber Tree and the protection of its habitat, considerable progress has been made toward the action:

• Develop and provide information to landowners, forestry associations and other sectors to increase awareness and promote protection and recovery of the species (Action No. 8). This action was implemented through projects supported by the Species at Risk Stewardship Fund in which partners offered workshops, tours, maps, factsheets and website content for woodland species at risk, including Cucumber Tree, to landowners, as well as engagement with volunteers on managing invasive species to protect species at risk.

The government’s recovery goal for Cucumber Tree is to conserve and achieve a self-sustaining population in Ontario. Efforts made toward the government-led and government-supported GRS actions have helped to make progress toward this goal. In addition, the provincial record of observations indicates that Cucumber Tree is exhibiting trends that are consistent with the GRS recovery goal. Although it is unknown what population size may be required to maintain a self-sustaining population, since 2008, observations have confirmed occupancy at seven of the provincial populations. The estimated viability of these populations ranges from good to poor, indicating that some populations are in good condition while a few are at risk of declining.

Recommendations

As stated in the GRS, the review of progress toward protecting and recovering Cucumber Tree can be used to help identify whether adjustments are needed to achieve the protection and recovery of the species. Based on progress to-date, the overall direction provided in the GRS for Cucumber Tree should continue to guide protection and recovery actions for the species, particularly actions identified as high priority in the GRS. Relative to actions that have received a high level of support, the following actions have received support to a lesser degree and may be considered in future decisions regarding the protection and recovery of Cucumber Tree:

• Actions for which progress has been limited should be supported in future implementation planning, such as supporting the securement of land where Cucumber Trees occur through existing land securement and stewardship programs (Action No. 3), assessing best opportunities for restoring connections between small populations to increase recruitment (Action No. 4) and investigating the potential impact on the Cucumber Tree of land-use activities that alter drainage patterns, groundwater and soil moisture (Action No. 7).
• Initial progress has been made toward conducting detailed pollination, demographic and seed dispersal studies and determining the genetic composition of populations (Action No. 6) and cooperating with existing initiatives to connect and expand forest fragments to increase potential suitable habitat (Action No. 5), Further work is still needed to fully address these actions for Cucumber Tree.

Moving forward, protecting and recovering Cucumber Tree will continue to be a shared responsibility that will require the involvement of many individuals, organizations and communities. Financial support for the implementation of actions may be available through the Species at Risk Stewardship Fund, Species at Risk Research Fund for Ontario or the Species at Risk Farm Incentive Program. The Ministry can also advise if any authorizations under the ESA or other legislation may be required to undertake a project. By working together, progress can continue to be made toward protecting and recovering Cucumber Tree in Ontario.

Summary of progress toward the protection and recovery of Cucumber Tree (2007-2015)

Provincial status:

• Cucumber Tree is classified as endangered under the Endangered Species Act, 2007 (ESA). Cucumber Tree was also listed under the previous Endangered Species Act, and has retained the same status since transition to the ESA. Cucumber Tree has received species and habitat protection since 1987.

Species-specific documents and guidance published by the government:

• Recovery Strategy for the Cucumber Tree (Magnolia acuminata) (2010)
• Cucumber Tree: Ontario Government Response Statement (2011)

Government-supported stewardship projects:

• Through the Species at Risk Stewardship Fund, the Ministry of Natural Resources and Forestry ("the Ministry") has enabled its stewardship partners to conduct a total of seven projects that have supported the protection and recovery of Cucumber Tree. One project ($7,600) focused exclusively on Cucumber Tree, while the other six projects ($160,266) focused on multiple species at risk, including Cucumber Tree.
• The Ministry’s support helped its stewardship partners to involve 481 individuals who volunteered 4,702 hours of their time toward protection and recovery activities for species at risk, including Cucumber Tree. The estimated value of these voluntary contributions, as well as additional funding and in-kind support, is $449,081.
• Stewardship partners reported providing outreach on multiple species at risk, including Cucumber Tree to 1,125 individuals.
• Through the Species at Risk Research Fund for Ontario the Ministry supported one research partner in conducting a conservation genetics study on Cucumber Tree that improved understanding of the species' biology and ecology.
• Through participation in the Conservation Land Tax Incentive Program (CLTIP; 20 properties) and Managed Forest Tax Incentive Program (MFTIP; 2 properties), private landowners protected natural heritage values and biodiversity, including Cucumber Tree on their land.

Supporting human activities while ensuring appropriate support for species recovery:

• The Ministry has issued one 'protection and recovery permit' issued under clause 17(2)(b) of the ESA.
• One activity has been registered for this species. The activity was registered under 'Threats to health and safety, not imminent' (section 23.18), under Ontario Regulation 242/08 of the ESA.

Occurrences and distribution:

• Thirteen populations of Cucumber Tree have been documented in the Niagara region and Norfolk county region. Currently, seven of these populations are extant, one is considered historical and the remaining five are considered extirpated. Since 2008, no new populations of Cucumber Tree have been identified; however, one population that was presumed to be extirpated was confirmed to exist. In addition, two populations that did not have observations for 20 years were confirmed to exist through monitoring efforts.

Related Information

• Categorizing and Protecting Habitat under the Endangered Species Act
• Natural Heritage Information Centre
• Ontario’s Endangered Species Act
• Ontario’s Endangered Species Act Regulation 242/08
• Ontario Recovery Strategy and Government Response Statement for Cucumber Tree
• Policy Guidance on Harm and Harass under the Endangered Species Act
• Species at Risk in Ontario List
• Species at Risk Stewardship Fund

References

Budd, C., E. Zimmer, and J.R. Freeland. 2015. Conservation genetics of Magnolia acuminata, an endangered species in Canada: Can genetic diversity be maintained in fragmented, peripheral populations? Conservation Genetics, 16(6), 1359-1373.

COSEWIC. 2010. COSEWIC assessment and status report on the Cucumber Tree Magnolia acuminata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 18 pp.