The Role of Mount Pleasant Cemetery in the ex situ Conservation of Tree Species at Risk of Extinction

by

Alexandra Noel

Submitted in conformity with the requirements for the degree of Master of Forest Conservation

Graduate Department University of Toronto

© Copyright by Alexandra Noel 2016

The Role of Mount Pleasant Cemetery in the ex situ Conservation of Tree Species at Risk of Extinction

Alexandra Noel

Master of Forest Conservation

University of Toronto

2017

Abstract

Protecting tree species at risk of extinction is an important global issue, but there is a lack of

research on the role that Canadian arboretums play in actively conserving these species ex situ

(UNEP, 2009; La Vie et al., 2009). In order to investigate this subject, a case study of Mount

Pleasant Cemetery (MPC) was conducted. MPC acts not only a cemetery, but as an arboretum

home to a wide variety of tree species. This study examines the role of MPC in the ex situ

conservation of tree species at risk by investigating the following questions: i) which tree species

at risk are currently held in the MPC collection? ii) and which species at risk are found in other

Canadian arboretum and botanical garden collections?

The results of this study show that Mount Pleasant Cemetery has the following Canadian tree

species at risk currently held in in their collection: Magnolia acuminate, Castanea dentata,

Fraxinus quadrangulata, Juglans cinerea, Ptelea trifoliate, Gymnocladus dioicus, Pinus flexilis,

and Morus rubra. While the average number of tree species at risk for other Canadian

arboretums and botanical gardens was 7, there are 8 at MPC. These findings demonstrate that

Mount Pleasant Cemetery has tree species at risk in their collection and that these species should

be managed accordingly. Specifically, MPC has the opportunity to play a role in the ex situ

i

conservation of these species through activities such as research, propagation, education, and

display.

ii

Acknowledgements

I would like to acknowledge my faculty supervisor, Professor Anne Koven, for her direction and

guidance. The assistance she provided was extremely helpful throughout the entire process of

completing this project.

I would also like to thank Jeff McMann and the Mount Pleasant Group of Cemeteries for the

opportunity to study this unique site and amazing collection of trees.

iii

Table of ContentsAbstract i

Acknowledgements iii

List of Tables vi

List of Figures vii

Introduction 1

Objectives 4

Methodology 5

Mount Pleasant Cemetery 5

Canadian Arboreta and Botanical Gardens 6

Limitations 6

Results 8

Tree Species at Risk in the Mount Pleasant Cemetery Collection 8

Magnolia acuminata (Cucumber tree) 10

Castanea dentata (American Chestnut) 10

Fraxinus quadrangulata (Blue Ash) 10

Juglans cinerea (Butternut) 11

Ptelea trifoliate (Common Hoptree) 12

Gymnocladus dioicus (Kentucky Coffee Tree) 12

Pinus flexilis (Limber pine) 13

Morus rubra (Red Mulberrry) 13

Species at Risk in Canadian Arboretums 14

Discussion 17

Mount Pleasant Cemetery 17

Canadian Arboreta and Botanical Gardens 18

Conclusion and Recommendations 19

Management 19

The Importance of Monitoring and Inventory 21

Data Sharing 21

iv

Further Research 22

References 23

Appendices 25

Appendix 1 25

Aerial View of Mount Pleasant Cemetery 25

Appendix 2 26

Tree Species at Risk in Canada 26

v

List of TablesTable 1: Tree Species at Risk in Mount Pleasant Cemetery 9Table 2: Species at Risk in Canadian Arboretums 14

vi

List of Figures Figure 1: Mount Pleasant Cemetery 2Figure 2: Mount Pleasant Cemetery Monument 5Figure 3: Number of Threatened, Endangered and Species of Special Concern in Mount Pleasant Cemetery 12

vii

List of AppendicesAppendix 1: Aerial View of Mount Pleasant Cemetery 22

Appendix 2: Tree Species at Risk of Extinction in Canada 23

viii

Introduction

Environmental degradation, particularly destruction of the world’s forests, has severely impacted

tree biodiversity worldwide (UNEP, 2009; Vie et al., 2009). Diversity of species is essential

within an ecosystem for promoting resilience in the face of environmental changes (Cardinale et

al. 2002; Chapin et al., 2000; Naeem et al, 1994). For this reason, there are several global

initiatives to combat the loss of biodiversity worldwide. The largest of these initiatives is the

Global Strategy for Plant Conservation (GSPC), an international agreement adopted by the

Parties to the Convention on Biological Diversity (CBD) in 2002. The GSPC has 16 distinct

targets for global plant conservation actions through 2020. Among these is Target 8: ‘75% of

threatened plant species in accessible ex situ collections, preferably in the country of origin, and

20% of them included in recovery and restoration programs’” (Sharrock et al. 2011). At the tenth

Conference of the Parties to the Convention on Biological Diversity, countries expressed

increased support for the GSPC and its targets. However, it was noted that, “If North America is

to achieve this Target, the North American botanical and plant conservation community must

work more strategically and more collaboratively” (Sharrock et al. 2011). Specifically, the

necessity of documenting taxa that are not being conserved effectively was emphasized. The

long term goal of the GSPC is to stop the continued loss of plant species, and doing so requires a

local, regional, and global effort.

While in situ conservation is preferable because it involves protecting a species in its natural

habitat, there is an increased focus on the role of ex situ conservation as a complementary

conservation approach (Cavender et al. 2016). Moreover, “the potential application of an ex situ

collection is to directly benefit species survival in the wild through in situ efforts such as

reintroduction or population augmentation.” (Sharrock et al. 2011). However, implementing ex

situ species conservation is easier said than done as it involves the development of genetically

diverse and representative collections (germplasm or living plants) that can be stored long-term.

This not only provides a safety net against extinction, but also supports in situ conservation

efforts (Newton and Oldfield 2012). Ideally, the implementation of ex situ conservation should

be documented and data should be shared in order to coordinate conservation efforts. Studies

have shown that botanical organizations across Canada, Mexico, and the United States make

1

significant but largely

unquantified contributions

toward Target 8 and this lack of

information hinders strategic

planning and collaborative

action to conserve North

America’s flora (Sharrock et al.

2011). Unfortunately, this lack

of coordination could impact

Canada and the rest of North

America’s ability to progress with conservation goals such as Target 8 of the Global Strategy for

Biodiversity Conservation.

In order to reach this target, it is essential for botanical gardens and arboretums to make the

conservation of species at risk of extinction a primary focus in their management plans.

However, the documentation and management of threatened species can be difficult to

accomplish, especially for organizations with large tree collections. Cavender et al. argue that

“Species conservation is mentioned in the mission statements of most major botanical gardens,

yet the actual conservation value of existing ex situ tree collections is low” (2016). For example,

the mission statement of the Royal Botanical Gardens states their commitment to “dedicate our

expertise in horticulture, conservation, science and education – together with our unique gardens,

facilities and natural lands – to inspire and nurture society’s commitment to the environment”

(Royal Botanical Gardens, 2016). Similarly, the mission statement of the Montreal Botanical

Garden is the following: “through its efforts in communication, conservation, education and

research, Space for Life guides humans to better experience nature” (Space for Life, 2016). This

paradox between intent and practice has been recorded in botanical gardens and arboreta across

the United States, however relatively little work has been done on this subject in Canada

(Cibrian-Jaramillo et al., 2013).

In order to gain insight into the role of Canadian botanical gardens and arboreta in the ex situ

conservation of tree species at risk of extinction, a case study was completed of Mount Pleasant

Cemetery (Figure 1). MPC, located in Toronto, Canada is not only a cemetery, but an arboretum

2

Figure 1: Mount Pleasant Cemetery

home to a large diversity of tree species. While the primary purpose of the property has

historically been focused on its role as a cemetery, it has more recently been recognized as a

multi-functional urban green space (Chevalier 2015). In particular, more attention has been

focused on the role of the cemetery as an arboretum holding several rare and endangered tree

species.

In 2015, a comprehensive digital database was created that includes every tree and woody shrub

on the property. This database not only provides information on the health, height, and crown of

each species, but it also includes the identification of each tree to the species level. This data can

be used to determine the number of tree species at risk in the MPC collection. This information

can also be used to maintain and improve upon the collection as well as to contribute data

towards initiatives such as the Global Strategy for Plant Conservation. In the present study, the

issues raised above are addressed, specifically examining the ex situ conservation of species at

risk located in the MPC tree collection.

3

Objectives

The primary objective of this study is to determine the role of Mount Pleasant Cemetery in the ex

situ conservation of tree species at risk of extinction. In order to reach this objective, it is

necessary to answer the following sub-questions: i) which species at risk are currently held in the

MPC collection? ii) and which species at risk are found in other Canadian arboretum and

botanical garden collections?

4

Methodology

Mount Pleasant Cemetery

Mount Pleasant Cemetery occupies approximately 83 hectares and was recognized as a National

Historic Site of Canada in 1876 (Mount Pleasant National Historic Site of Canada, 2015, 2015).

This important designation was given because of the many significant funeral monuments

located on the property as well as the diverse collection of rare tree species.

A digital tree inventory was conducted in 2015 which includes every tree and woody shrub on

the property. The MPC data was collected using ArborPro software installed on a tablet which

allowed for the spatial mapping of each individual tree using Google Earth (Chevalier, 2015).

The inventory includes important information regarding the species identification of each tree

and shrub on the property with a diameter at breast height (DBH) of over 5cm. This inventory

was updated in 2016 to include any changes

that had occurred during the course of the year

and to confirm the work completed during the

previous year.

The Mount Pleasant Cemetery tree species data

collected in 2015 and 2016 was used to

determine the number of tree species at risk in

the MPC collection. The list of tree species was

cross-referenced with the Canadian Species at

Risk Public Registry which includes the

species’ status under the Committee on the

Status of Endangered Wildlife in Canada

(COSEWIC) and the Species at Risk Act

(SARA) as well as the schedule of the species.

The COSEWIC status is determined by a

committee of experts responsible for

designating which Canadian species are at risk

5

Figure 2: Mount Pleasant Cemetery Monument

of going extinct. The following are the five categories that the species can be placed into: extinct

(no longer exists), extirpated (no longer exists in Canada), endangered (facing imminent

extinction or extirpation), threatened (likely to become endangered if nothing is done to curb the

factors influencing the species’ decline), special concern (may become threatened or endangered

based on a combination of biological characteristics and identified threats), data deficient

(available information is insufficient to resolve a species’ eligibility for assessment or permit an

assessment of the species’ risk of extinction), and not at risk (has been evaluated and determined

not to be at risk of extinction). The SARA status refers to the level of protection given to the

species under federal law and uses the same five categories. Schedule 1 of the Act includes the

official list of all wildlife species at risk. Species not placed on Schedule 1 must be reassessed by

COSEWIC before they are listed and protected under SARA. Once a species is listed, the

measures to protect and recover the species are implemented.

Canadian Arboreta and Botanical Gardens

The second part of this paper involves research into the tree species at risk located in major

Canadian arboretums and botanical garden collections. This includes all the tree species at risk

held in the collection as well as the number of individuals of each species, where available. Nine

arboreta and botanical gardens located across Canada were analyzed in this study based on what

information was readily available. Species information was primarily accessed through online

resources, such as the organization’s website as well as the online data sharing site,

Canadadensys. Emails were also sent to several organizations if species information was not

accessible online.

Limitations

There are several important limitations that must be noted in this study. Firstly, it would have

been ideal to include every arboretum and botanical garden in Canada in this study. However,

this was not possible due to time and resource constraints. Secondly, the information gathered

from each arboretum and botanical garden in this study was self-reported and it was not possible

to confirm that all of the information was accurate. It is conceivable that the organizations

included in this study had more or fewer species at risk in their collections than was reported, but

6

this information was not readily available due to a lack of documentation. Finally, it is important

to note that genetic analysis was not performed on any of the tree species at risk at MPC. This

type of analysis can be important in order to confirm the identification of species such as Juglans

cinerea and Morus rubra which often hybridize with other species. Genetic analysis can also be

important for determining the genetic quality of a specific individual and, therefore, its value in

ex situ conservation efforts focused on species at risk.

7

Results

Tree Species at Risk in the Mount Pleasant Cemetery Collection

There are eight tree species at risk present in the Mount Pleasant Cemetery tree collection and 77

individual tree species at risk in total. These species are Magnolia acuminata, Castanea dentata,

Fraxinus quadrangulata, Juglans cinerea, Ptelea trifoliata, Gymnocladus dioicus, Pinus flexilis,

and Morus rubra (Table 1) (Figure 2). Magnolia acuminate, Castanea dentata, and Juglans

cinerea are all listed as endangered by COSEWIC and SARA. Morus rubra and Gymnocladus

dioicus are listed as threatened by COSEWIC and SARA. Fraxinus quadrangulata is listed as

threatened by COSEWIC and by SARA as special concern. Ptelea trifoliata is listed as special

concern by COSEWIC and threatened by SARA. Pinus flexilis is listed as endangered by

COSEWIC and has no status under SARA.

8

Table 1: Tree Species at Risk in Mount Pleasant Cemetery

Common

Name

Scientific

Name

Committee on the

Status of

Endangered

Wildlife in

Canada

(COSEWIC)

Status

Schedule

Species at

Risk Act

(SARA)

Status

Number of

Individuals at

Mount

Pleasant

Cemetery

Cucumber

Tree

Magnolia

acuminataEndangered

Schedule

1Endangered 3

American

Chestnut

Castanea

dentataEndangered

Schedule

1Endangered 3

Blue AshFraxinus

quadrangulataThreatened

Schedule

1

Special

Concern5

ButternutJuglans

cinereaEndangered

Schedule

1Endangered 5

Common

Hoptree

Ptelea

trifoliataSpecial Concern

Schedule

1Threatened 3

Kentucky

Coffee

Tree

Gymnocladus

dioicusThreatened

Schedule

1Threatened 46

Limber

PinePinus flexilis Endangered

No

ScheduleNo Status 9

Red

MulberryMorus rubra Threatened

Schedule

1Threatened 3

Magnolia acuminata (Cucumber tree)

There are three Magnolia acuminata trees located at Mount Pleasant Cemetery. This striking tree

is found in southwestern Ontario as well as areas of the eastern United States. The most recent

9

population estimation was completed in 2001 and concluded that 226 Magnolia acuminata trees

were present in 15 sites across Canada. Magnolia acuminata is a shade-intolerant species and

requires good light conditions for regeneration. The main limiting factor for this species is

habitat loss due to logging and clearing for agriculture and the species is listed as endangered by

both COSEWIC and SARA (Government of Canada, 2016).

Castanea dentata (American Chestnut)

There are three Castanea dentata trees in Mount Pleasant Cemetery. It is a deciduous tree found

almost exclusively in the United States, but can also be found in southern Ontario due to the

moderating effect of the Great Lakes. There are currently only 140 documented sites in Canada

where this tree can be found. Blight fungus, which establishes itself as cankers on the trunk of

the tree, is the leading threat to this tree species. Castanea dentata has been identified by

COSEWIC as an endangered species and is protected under the SARA. Aside from the three

trees located at MPC, most of these trees are located on land belonging to public agencies such

as conservation authorities, counties and districts, and the Ministry of Natural Resources

(Government of Canada, 2016).

Fraxinus quadrangulata (Blue Ash)

Mount Pleasant is home to 5 Fraxinus quandrangulata trees. This species is native to the

Carolinian forest and can be found in the southern part of Canada and much of the United States.

In Canada, the habitat for blue ash is either rich floodplain forest, shallow soil over dry

limestone, or well-drained sand. Areas with this type of habitat, such as southern Ontario, are

highly developed which limits the land available for blue ash. In some places, the clearing of

floodplain forests removes blue ash trees and cattle grazing can prevent seedling establishment.

Moreover, vineyard expansion and low reproduction levels negatively influence the population

numbers of this species. In 2015, it was noted that browsing from white-tailed deer and the

presence of the invasive Emerald Ash Borer had caused further decline of this species at most

sites. The small population size and fragmentation of this species has made it difficult to recover.

This species is listed as threatened by COSEWIC and is considered special concern under SARA

(Government of Canada, 2016).

10

Juglans cinerea (Butternut)

There are five Juglans cinerea trees located in Mount Pleasant Cemetery. This species is found

in deciduous stands in northeastern and north central North America. In Canada, Juglans cinerea

is native to the provinces of Ontario, Quebec, and New Brunswick. While there are several

threats to Juglans cinerea such as logging, urban development, leaf spot, and root disease, the

most severe of these is Butternut canker which kills a large number of individuals each year. The

canker has spread from the United States to Canada and there has been no progress in curbing its

progression. There is a provincial Butternut recovery team in Ontario that is working towards the

development and distribution of a standardized tree assessment form and a regional program to

collect seed from healthy Butternut trees that have not been stricken with Butternut canker.

Juglans cinerea is currently listed as endangered by both COSEWIC and SARA (Government of

Canada, 2016).

11

Ptelea trifoliate (Common Hoptree)

Three Ptelea trifoliate are currently held in the Mount Pleasant Cemetery tree collection. This

species is shade intolerant and often grows in highly disturbed areas such as a shoreline or sand

point. Due to its unique habitat requirements, one of the main threats to this species is habitat

loss from cottage development. Ptelea trifoliate is listed as threatened by SARA and special

concern by COSEWIC (Government of Canada, 2016).

Gymnocladus dioicus (Kentucky Coffee Tree)

Mount Pleasant Cemetery is home to 46 Gymnocladus dioicus trees. The habitat of this species

includes floodplains and the edges of wetlands in southern Ontario. Gymnocladus dioicus usually

reproduces vegetatively by sending up root suckers rather than by seed. Therefore, most

populations consist of single-sex clones. Climate change, suitable habitat, and lack of seed

reproduction are all limiting factors for this species. Current recovery initiatives are numerous

and include living gene bank collections and stewardship initiatives. The species is listed as

endangered by both COSEWIC and SARA (Government of Canada, 2016).

12

Threatened Endangered Special Concern0

1020304050

Number of Threatened, Endangered, and Species of Specieal Concern in Mount Pleasant Cemetery

Fraxinus quadrangulata Magnolia acuminata Castanea dentataJuglans cinerea Ptelea trifoliata Gymnocladus dioicusPinus flexilis Morus rubra

COSEWIC Species Listing

Num

ber o

f Ind

ivid

uals

Figure 2: Number of Threatened, Endangered and Species of Special Concern in Mount Pleasant Cemetery

Pinus flexilis (Limber pine)

Nine Pinus flexilis trees can be found at Mount Pleasant Cemetery. This species is a keystone

species, otherwise known as a species depended upon by other species in an ecosystem such as

bears, small mammals, and birds. White Pine Blister Rust, an introduced pathogen, is a severe

threat to this species as is Mountain Pine Beetle. Pinus flexilis is currently listed as an

endangered species by COSEWIC (Government of Canada, 2016).

Morus rubra (Red Mulberrry)

There are three Morus rubra trees at Mount Pleasant Cemetery. This species has been found in

18 locations in southern Ontario, but only 8 of these sites contain five or more individuals. Land

clearing and the altering of drainage patterns are the main threats to Morus rubra. However, the

presence of Morus alba (white mulberry), an aggressive exotic, is also thought to have a negative

impact on this species as the two often hybridize. While the culling of Morus alba has been

attempted, it did not prove successful due to the competitive advantage of Morus alba which

allows the species to outcompete Morus rubra. This species is currently listed as threatened by

COSEWIC and SARA (Government of Canada, 2016).

13

Species at Risk in Canadian Arboretums

Table 2 gives a list of every tree species at risk found in each of the nine arboreta and botanical

garden collections. This table also includes the total number of tree species at risk found in each

of the nine collections as well as the total number of individual tree species at risk found in each

collection.

Table 2: Species at Risk in Canadian Arboretums

Arboretum or

botanical

garden

LocationTree species at risk held

in the collection

Total

number

of tree

species at

risk

Combined

total number

of individuals

of these

species

Mount Pleasant

Cemetery

Toronto,

Ontario

Castanea dentata,

Magnolia acuminata,

Fraxinus quadrangulata,

Juglans cinerea, Morus

rubra, Gymnocladus

dioicus, Pinus flexilis,

Ptelea trifoliata

8 77

University of

Guelph

Arboretum

Guelph, Ontario

Magnolia acuminata,

Fraxinus quadrangulata,

Juglans cinerea, Morus

rubra, Gymnocladus

dioicus, Quercus

shumardii, Cornus florida,

Betula lenta, Ptelia

trifoliata

9 103

14

University of

British

Columbia

Botanical

Garden

Vancouver,

British

Columbia

Ptelia trifoliate, Fraxinus

quadrangulata, Quercus

shumardii, Gymnocladus

dioicus, Magnolia

acuminata, Betula lenta,

Cornus florida

7 27

VanDusen

Botanical

Garden

Vancouver,

British

Columbia

Castanea dentata, Fraxinus

quadrangulata, Juglans

cinerea, Betula lenta,

Magnolia acuminata,

Celtis tenuifolia, Cornus

florida, Pinus flexilis,

Quercus shumardii, Pinus

albicaulis

11 17

Memorial

University

Botanical

Garden

St. John’s

NewdoundlandN/A 0 0

Royal Botanical

Gardens (RBC)

Burlington,

Ontario

Betula lenta, Castanea

dentata, Juglans cinerea,

Morus rubra, Cornus

florida, Gymnocladus

dioicus, Magnolia

acuminata, Ptelia trifoliata

8Data not

available

Montreal

Botanical

Garden

Montreal,

Quebec

Pinus flexilis, Juglans

cinerea, Betula lenta,

Fraxinus quadrangulata,

Cornus florida, Ptelia

trifoliate, Celtis tenuifolia,

Castanea dentata,

Gymnocladus dioicus,

10 26

15

Magnolia acuminata

Morgan

Arboretum

Sainte-Anne-de-

Bellevue,

Quebec

Gymnocladus dioicus,

Betula lenta, Juglans

cinerea, Magnolia

acuminata, possibly Pinus

flexilis

4 or 5 Approx. 287

University of

Saskatchewan

Patterson

Arboretum

Saskatoon,

Saskatchewan

Fraxinus quadrangulata,

Juglans cinerea, Betula

lenta, Ptelia trifoliate,

Magnolia acuminata,

Celtis tenuifolia,

Gymnocladus dioicus,

Pinus flexilis, Morus rubra,

Pinus, albicaulis

10Data not

available

Hariet Irving

Botanical

Gardens

Wolfville, Nova

ScotiaJuglans cinerea 1 1

Average 6.7 51.2

16

Discussion

Mount Pleasant Cemetery

Of the 13 tree species at risk in Canada, Mount Pleasant Cemetery was found to have eight of

these in their collection (Table 1). This includes 3 Magnolia acuminata, 5 Juglanc cinerea, 46

Gymnocladus dioicus, 3 Morus rubra, 5 Fraxinus quadrangulata, 3 Castanea dentata, 9 Pinus

flexilis, and 3 Ptelea trifoliata. All of these species are protected under SARA except for Pinus

flexilis which is considered to be endangered by COSEWIC but has not yet been added to

Schedule 1. Keeping these species in the cemetery tree collection is important for the ex situ

conservation of the species as it provides a ‘safety net’ or insurance against the extinction of

these species in the wild. This is especially important in light of climate change as habitats are

shifting at a rate that is faster than species can adapt (Global Strategy for Plant Conservation,

2012). “Rapid climate change puts species at risk of extinction by shifting the ‘climate envelope’

within which they can persist outside of their current geographic range (Davis and Zabinski

1992, Thomas et al. 2004)” (McLachlan et al. 2005). If trees are pushed to migrate outside of

their original habitat, this could have profound impacts on tree species, particularly those that are

already at risk of extinction. Holding these species in an ex situ collection affords a safeguard

and lessens the danger of losing the species altogether.

Target 8 of the Global Strategy for Plant Conservation recommends that at least 75 per cent of

threatened plant species be held in ex situ collections, preferably in the country of origin, and at

least 20 per cent available for recovery and restoration programmes (Sharrock et al. 2011). In

terms of tree species, Mount Pleasant Cemetery is contributing to this initiative and currently

holds 61.5% of Canada’s tree species at risk in their collection. Living collections of at risk tree

species can be used for several important functions. These functions include, but are not limited

to, the following: horticulture and research, propagation of plants to remove or reduce pressure

from wild harvesting, display, education and community engagement activities, species

reintroduction and habitat restoration programs (Global Strategy for Plant Conservation, 2012).

17

The knowledge of what species at risk are currently present in the MPC collection can be used to

improve upon the collection and potentially add species at risk to the collection or more

individuals of a particular ‘at risk’ species. The digital tree and shrub database used by MPC

makes it relatively easy to record and update information related to any new individuals added to

the collection over time so that the collection can be managed and, ideally, improved upon.

Maunder et al. argue that the following important factors should be considered in order to

increase the conservation value of a tree collection: available resources and space, the existing

collection, local scientific expertise, regional habitat and climate (and predicted future climate),

and the interests of the local community (2004). MPC is a site with a unique set of challenges

and opportunities that must be addressed in its tree care and management. For MPC, an

organization with many competing interests, it is doubly important that each tree added to the

collection be chosen pragmatically with care and consideration.

Canadian Arboreta and Botanical Gardens

Every arboretum and botanical garden included in this study has at least one species at risk in

their collection with the exception of Memorial University Botanical Garden. The average

number of species at risk held in the arboreta and botanical garden collections was 6.7 and the

average number of ‘at risk’ individuals was 51.2. MPC had a higher than average number of

species at risk in their collection with 8 species at risk in total and a higher number of ‘at risk’

individuals with 77 in total. This information suggests that MPC has a valuable collection of

trees when it comes to ex situ conservation of tree species at risk as is above average when

compared with other organizations in Canada. This is especially impressive when considering

that MPC has the added challenge of balancing the allocation of grave space and space for trees

which is not an issue for other botanical gardens and arboreta. While the other organizations

included in this study identify primarily as botanical gardens or arboreta, with mandates

reflecting their respective title, MPC is predominantly focused on its role and management as a

cemetery. The above average number of tree species at risk in the MPC collection is particularly

notable when considering the other priorities that the organization is faced with.

18

Conclusion and Recommendations

Management

It is recommended that the protection and management of the tree species at risk highlighted in

this study become a more central aspect of the management of the cemetery as a whole. As was

demonstrated, MPC has a valuable collection of tree species at risk that is above average when

compared with the other Canadian botanical gardens and arboreta examined in this study. Taking

full advantage of these trees for research, education, and propagation is an important next step as

well as sharing this data with other organizations so that these species can be protected and

recovered on a regional scale. MPC is already involved in many initiatives such as scientific

research, education, and community engagement activities. The large number of diverse trees at

MPC make it an ideal location to conduct research on trees and several universities have already

taken advantage of this excellent opportunity. Mount Pleasant is also open to the public every

day and hosts a large number of people who come to walk, run, or simply enjoy the picturesque

setting. Moreover, the cemetery hosts a tree tour bi-annually showcasing a few of the many

interesting trees on the property. This is an excellent opportunity to engage the public and

display some of the rarer species at MPC.

There is also room for MPC to improve its efforts towards the ex situ conservation of tree species

at risk and to utilize its unique collection to the fullest extent. The propagation of ‘at risk’ tree

species and the reintroduction of these species into their natural habitat presents a chance to work

in conjunction with local Universities. This is not only an opportunity to reduce the risk of these

species going extinct in the wild, but provides a unique learning opportunity for students. There

are no propagation programs currently taking place at MPC and this is an area that could be

expanded upon in the future. There is the potential to create projects aimed at specific species

such as Morus rubra. This species freely hybridizes with Morus alba, controlled pollination is

necessary in order to make sure that red mulberry pollen reaches the flowers. This method has

been implemented at the Royal Botanical Gardens and involves collecting pollen from one plant

with desirable traits and using this to pollinate the mother or seed producing plant (Caddy and

Iwanycki, 2012). While Mount Pleasant may not have the time and resources to implement this

19

type of initiative on their own, it could be a chance to work in conjunction with educational or

horticultural institutions.

There are several funding options available to organizations and businesses that wish to actively

engage in the protection and recovery of species at risk. One such opportunity is Canada’s

Habitat Stewardship program (HSP) which is administered by Environment and Climate Change

Canada and managed co-operatively with Fisheries and Oceans Canada and the Parks Canada

Agency. The program was established in conjunction with Canada’s national strategy for the

protection of species at risk with the goal of “contributing to the recovery of endangered,

threatened, and other species at risk, and to prevent other species from becoming a conservation

concern, by engaging Canadians from all walks of life in conservation actions to benefit

wildlife” (Government of Canada, 2016). Additionally, the program fosters partnerships among

organizations interested in the recovery of species at risk. HSP has two streams of funding. The

first deals with projects focusing on the recovery of species at risk listed under Schedule 1 of

SARA. Seven of the eight species at risk in the MPC collection are listed under Schedule 1 and

would, therefore, be eligible under this stream of funding. The second stream addresses projects

focused on other species that are not listed on SARA to prevent them from becoming a

conservation concern (Gov’t of Canada, 2016). This stream may apply to other trees in the MPC

collection that are not yet considered to be species at risk, but require conservation efforts in

order to maintain their population numbers.

While there are many positive aspects associated with the presence of tree species at risk at

MPC, there are also potential negatives. This could include prohibited actions related to these

species. While SARA prohibitions apply only to aquatic species and migratory birds, the Ontario

Endangered Species Act includes several prohibitions pertaining to species at risk of extinction

(SARA, 2016). The most relevant to MPC is number nine which states that “no person shall kill,

harm, harass, capture or take a living member of a species that is listed on the Species at Risk in

Ontario List as an extirpated, endangered or threatened species” (Gov’t of Ontario, 2015). Of the

eight species at risk in MPC this applies to Magnolia acuminata, Castanea dentata, Juglans

cinerea, Ptelea trifoliata, Morus rubra, Gymnocladus dioicus and Fraxinus quadrangulata. It

does not apply to Pinus Flexilis as it is not currently listed as an endangered or threatened

species in Ontario. As Mount Pleasant is a cemetery, there is often competition for space

20

between graves and trees. However, due to this prohibition it will not be possible to cut down

any of the tree species at risk on the property regardless of their location or their infringement

upon graves, potential grave space, or other development projects.

The Importance of Monitoring and Inventory

The importance of monitoring and inventory cannot be overstated when it comes to the

management of tree collections. Knowing what is in a collection is the first step towards

maintaining the integrity of the collection and building upon it. While Mount Pleasant Cemetery

has a relatively advanced inventory system which includes a digital database with every tree on

the property, this is not the case for many arboreta and botanical gardens in Canada which have

not completed an inventory or use a non-digitized system which is difficult to update and

maintain. These organizations are not able to specify the number of tree species at risk in their

collections. Since the protection of these species requires the combined efforts and data sharing

between multiple organizations, it is essential that collections be inventoried and remain up to

date.

Data Sharing

There are several ways in which organizations with significant tree collections, such as MPC,

can share their data. Websites such as Canadensys allow organizations to make their data public

so that anyone can access and use this information. This is important for larger research

initiatives that require data from multiple organizations across Canada. Botanical Gardens

Conservation International (BGCI) is the largest plant conservation network in the world and is a

forum for collaboration between botanical gardens, arboreta, and related institutions (Plant

Conservation in Canada, 2016). An important feature offered by BGCI is the PlantSearch

database which is the only global database of plant species in botanic gardens and similar

organizations. PlantSearch is the primary tool by which progress towards Target 8 of the Global

Strategy for Plant Conservation is measured. It also serves to connect collections directly to

relevant groups such as conservationists, educators, and policy makers (BGCI, 2016).

Organizations such as this offer an opportunity to share knowledge and participate in

conservation activities at a regional and global scale.

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Further Research

It is recommended that further research on this subject include a larger number of botanical

gardens and arboreta. While Mount Pleasant Cemetery represents an interesting case study, there

are between 70 and 100 botanical gardens, arboreta, and related facilities in Canada (Plant

Conservation in Canada, 2016). There are also likely to be other organizations such as MPC that

are not classified as botanical gardens or arboreta, but have a number of tree species at risk in

their collections that have yet to be recognized. By determining the current contribution of

Canadian arboreta, botanical gardens, and other organization towards ex situ tree species

conservation, it will be possible to make recommendations that will improve their management

practices and improve conservation strategies for the future.

22

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McLachlan, J. S., Clark, J. S., & Manos, P. S. (2005). Molecular indicators of tree migration capacity under rapid climate change. Ecology, 86(8), 2088-2098.

M.Maunder , E.O.GuerrantJr , K.Havens & K.Dixon (2004) Realizing the full potential of ex situ contributions to global plant conservation. In Ex Situ Plant Conservation: Supporting Species Survivial in the Wild (eds E.O. Guerrant Jr , K. Havens & M. Maunder ). Island Press, Washington, DC, USA.

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Appendices

Appendix 1

Aerial View of Mount Pleasant Cemetery

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Appendix 2

Tree Species at Risk in CanadaBetula lenta (Cherry Birch)

Castanea dentata (American Chestnut)

Juglans cinerea (Butternut)

Morus rubra (Red Mulberry)

Cornus florida (Eastern Flowering Dogwood)

Gymnocladus dioicus (Kentucky Coffee Tree)

Magnolia acuminate (Cucumber Magnolia)

Ptelea trifoliata (Common Hoptree)

Pinus flexilis (Limber Pine)

Fraxinus quadrangulata (Blue Ash)

Celtis tenuifolia (Dwarf Hackberry)

Pinus albicaulis (Whitebark pine)

Quercus shumardii (Shumard Oak)

26