Approaches To Conservation And Sustainable Use Of Biodiversity- A Review
Senior Thesis Paper
1. AN ANALYSIS OF THE BIODIVERSITY AND TREE AGE STRUCTURE IN
CLINTON, IOWA’S URBAN FOREST
by
Jacob Michael Smith
A senior thesis submitted in partial fulfillment
of the requirements for the degree
of
Bachelor of Arts
in
Environmental Studies
AUGUSTANA COLLEGE
Rock Island, Illinois
February 2016
3. ii
ACKNOWLEDGEMENTS
I would like to thank Dr. Matthew Fockler for mentoring and assisting me in the research,
writing, and map making process of my senior inquiry. I would also like to thank Dr. Michael
Reisner for his aid throughout my research project. A special thanks to the faculty and students
of Augustana College’s Environmental 380 Special Topics course, the Davey Resource Group,
and the Upper Mississippi Center for their aid in collecting and providing me with the necessary
tree inventory data that made my research possible. I also would like to thank my fellow
colleagues for listening to my research presentation and providing beneficial feedback. Lastly, I
would like to thank Dr. Reuben Heine for his help in developing a methodology for this research.
4. iii
TABLE OF CONTENTS
Introduction…………………………………………………………………………………….....1-2
Study Area………………………………………………………………………………...............3-5
Literature Review…………………………………………………………………………………6-10
Biodiversity………………………………………………………………….....6-7
Urban Forests and Stresses……………………………………………………..8-9
Biodiversity Management…..…………………………………………………..9-10
Methodology…………………………………………………………………..………………....9-13
Results……………………………………………………………………………………………15-18
Discussion………………………………………………………………………………………..19-22
Bibliography……………………………………………………………………………………...23-24
Appendix 1……………………………………………………………………………………….25- 29
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LIST OF TABLES
Table Page
1. Table 1: Analysis Areas’ Shannon Values…….…………………………………….17
LIST OF FIGURES
Figure Page
1. Figure 1: Study Area Map………………………………………………………...5
2. Figure 2: Analysis Area Map……………………………………………………..12
3. Figure 5: Private Tree Map……………………………………………………….13
4. Figure 6: Public Tree Map………………………………………………………..14
5. Figure 5: Shannon Diversity Map………………………………………………..17
6. Figure 6: Tree Age Structure Map……………………………………………….18
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ABSTRACT
Biodiversity and tree age structure diversity are key components to maintaining and/or
enhancing the aesthetic and ecological value that urban forest ecosystems provide for human
well-being. This study analyzes the current state of Clinton, Iowa’s urban forest in terms of tree
genus diversity and age structure diversity in order to develop an urban forest planting regime
that aims to foster species and genus richness, while also planting for an even tree age structure.
Using Clinton’s tree inventory, the Shannon’s Diversity Index, and spatial interpolation, it could
be concluded that Clinton, like other cities in the Upper Mississippi River Valley, has a lack of
biodiversity and an uneven age structure throughout its urban forests. As a result of this study,
specific areas in Clinton have been identified as areas of concern due to their high public
visibility, large numbers of trees, low levels of diversity, and lack of an even age structure.
These areas of concern could benefit significantly from the implementation and management of
an urban forest planting regime that aims to foster biodiversity and tree structure diversity, with
the overall goal of enhancing tree genus and age diversity throughout Clinton’s urban forest.
7. 1
Introduction
Biodiversity is a critical ecosystem service that is in dire need of management. Human
well-being and other ecosystem services are directly dependent upon it (Naeem et al. 1999;
Alvey 2006; Chapin lll et al. 2009; Cardinale et al. 2012). High levels of biological diversity
within social-ecological system functional groups promote resilience and sustainability (Chapin
lll et al. 2009). A biodiverse functional group acts as insurance against the loss of a species, thus
well-being and vital ecosystem services are preserved.
Biodiversity loss is a global phenomenon that threatens ecosystem services and human
well-being (Cardinale et al. 2012). Knowing the importance of biodiversity is important in order
to maintain and/or enhance current levels of biodiversity within social-ecological systems across
the globe. By 2100, global biodiversity losses could be between 50 and 75 percent (Naeem et
al. 1999). Biodiversity loss mostly occurs from human induced habitat loss by means of
deforestation, urban sprawl, and introduction of pest and diseases caused by biotic
homogenization (McKinney 2006). When humans design cities we tend to only develop them to
meet the needs of our species and this plays a large role in biodiversity loss and the degradation
of critical ecological services within our urban forests (McKinney 2006).
Urban forests are any collection of trees that live within an urban environment. These
forests are comprised of private land trees, public park and right of way trees, and trees that
naturally exist within an urban boundary. Urban forests play a vital role in the maintenance of
biodiversity and critical ecosystem services, such as water regulation and air filtration, nutrient
cycling, carbon sequestration, microclimatic regulation, and soil maintenance (Bolund and
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Hunhammar 1999). Therefore, urban forests greatly contribute to the resilience and
sustainability that comes with high levels of functional group biodiversity (Nyström 2006).
A majority of the world’s population now resides in urban areas and these populations
depend on healthy and intact ecosystem services that urban forests provide for survival (Collinge
1996; Alvey 2006). However, biodiversity in urban forests is threatened by habitat
fragmentation, climate change, and introduction of invasive species (Collinge 1996; Alvey
2006). Many urban forests are under attack from anthropogenic sources and require an in-depth
urban forest management plan to preserve the integrity of their ecosystem services (Chapin lll et
al. 2009).
This paper focuses on urban forests and their importance within a social-ecological
system. This research makes use of the Shannon Diversity Index and spatial interpolation in
ArcGIS to interpret the level of tree diversity within Clinton, Iowa’s urban forest. The analysis
of this information will allow an urban forest planting regime to be designed and incorporated.
The planting regime will be based on areas of concern in order to enhance tree species’ diversity,
tree age diversity, resilience, and sustainability in Clinton’s urban forest.
Clinton’s urban forest is currently dominated by the maple genus and is also lacking tree
age evenness. Both stresses pose serious threats to the biodiversity, resilience, and sustainability
of Clinton’s urban forest. Many other urban forests throughout the Upper Mississippi River
Valley are suffering from these same ailments. The methods as well as the planting regime
itself can act as a template for other cities facing similar stresses who wish to analyze the health
of their urban forest and implement an urban forest management plan that addresses
9. 3
enhancement and/or preservation of their urban forests and the vital ecosystem services they
provide.
Study Area
This study was conducted in Clinton, Iowa which is located in the Upper Mississippi
River Valley in the eastern part of Clinton County (Figure 1). Clinton is located along the
western shores of the Mississippi River and spans a total area of 38.01 square miles (U.S. Census
Bureau 2014).
The Upper Mississippi River Valley is currently under threat of losing species diversity.
In floodplain forests of the Upper Mississippi River Valley, oak and hickory species are in
decline, and flood and shade-tolerant silver maple is to dominant. These forests are also losing
the green ash species of trees as the Emerald Ash Borer (EAB) beetle continues to migrate
westward (Romano 2010).
Clinton is a critical location to conduct urban forest biodiversity and resilience research
because the city of Clinton is currently encountering a lack of urban forest biodiversity.
Increasing the tree species’ diversity within Clinton’s urban forest is critical because enhancing
biodiversity will act as ecological insurance in the face of stresses and disturbances (Nyström
2009). Other cities within the Upper Mississippi River Valley are currently dealing with an EAB
infestation and maple dominance. The biodiversity, resilience, and EAB research that has been
conducted for the urban forest planting regime for Clinton is important because they allow for
replication and implementation of similar urban forest planting regimes for any cities that
currently do not have an urban forest plan. Such a plan may help them prevent a further decline
in tree diversity due to disease or pest infestation and/or a tree monoculture presence.
10. 4
The goal of this study is to analyze the biodiversity of Clinton’s urban forest in greater
depth to determine areas of biodiversity concern in order to establish an effective urban forest
planting regime. This planting regime can then be implemented to enhance species diversity in
areas of concern in order to foster biodiversity and resilience within Clinton’s social-ecological
community.
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Figure 1: This figure represents a map of Clinton,IA including its city limits and proximity to the
Mississippi River. Map by author.
12. 6
Literature Review
Biodiversity
Biodiversity plays an important role in fostering resilience in social-ecological systems
by stabilizing certain ecosystem services (Alvey 2006; Chapin lll et al. 2009). Human well-
being is dependent on a multitude of ecosystem services, including regulating, supporting,
provisional, and cultural services. Biodiversity is a supporting service that other ecosystem
services are dependent upon (Chapin lll et al. 2009). Ecosystems with higher levels of
biodiversity tend to be more resilient to exogenous stresses and disturbances than systems with
lower levels of biodiversity (Peterson et al. 1998). High orders of biodiversity at the species
level act as an insurance policy for ecosystem services against stresses and disturbances such as
disease and pest infestation, drought, flooding, and invasive species. Biodiversity degradation
can then have a negative impact on human well-being, increase social-ecological systems
vulnerability to stresses, thereby lowering their resilience (Peterson et al. 1998). Proper
management techniques to maintain or foster biodiversity should be taken (Chapin lll et al.
2009).
Biodiversity is typically thought of as the number of species, or species richness, present
in an ecosystem. This is an important part of biodiversity because as species richness increases
in an area, the invasibility of invasive species decreases due to increased competition for
nutrients (Hooper et al. 2005). Species richness is a critical aspect, but it is not the only
important aspect of biodiversity (Thompson et al. 2009). Chapin lll et al. (2009) explains that
the maintenance of biodiversity factors such as effect diversity, response diversity, keystone
species, functional types, and functional redundancy all play vital roles in fostering ecosystem
resilience. Functional redundancy and response diversity are two imperative elements of
13. 7
biodiversity that are enhanced by species richness (Chapin lll et al. 2009). The maintenance of a
large diversity of species that contributes to the same ecosystem function, or functional
redundancy, increases the capacity of multiple species to compensate for the loss of another
species within that functional group. This conservation of diversity among functional groups
acts as a preventative measure to stresses and disturbances and can increase resilience in
ecological services (Nyström 2006). However, functional groups containing high functional
redundancy can actually increase vulnerability to stresses and disturbances if there is low
response diversity within the group (Nyström 2006). High response diversity mixed with high
functional redundancy within a functional group reduces the vulnerability of a social-ecological
system while increasing its resilience (Nyström 2006).
Effect diversity is another aspect of biodiversity that should be taken into account when
evaluating the overall biodiversity of an ecosystem. In agricultural landscapes, high effect
diversity can have ecological and economic benefits by reducing exposure to herbivores,
pathogens, weeds, and the invasion of invasive species by increasing the amount of natural
predators present in an ecosystem. This in turn enhances the overall resilience of that
ecosystem. Polycultures not only create biodiversity within an ecosystem they also reduce the
cost of pest and disease control for agriculturists while increasing the amount of pollinators that
food crops depend on. Biodiversity has economic and ecological benefits as aforementioned
above, but when considering human well-being it is also important to evaluate the biodiversity of
urban forests and the multitude of benefits that it provides for humans residing in urban
communities (Chapin lll et al. 2009).
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Urban Forests and Stresses
Human health is dependent on urban forests for ecosystem services and well-being
(Bolund and Hunhammar 1999). These urban ecosystems provide the following services that are
beneficial to human welfare: air filtration, microclimatic regulation, reduced water runoff,
recreational and cultural values, carbon sequestration, and noise reduction (Bolund and
Hunhammar 1999). These benefits can be mitigated by exogenous and endogenous stresses and
disturbances endemic to urban landscapes (Collinge 1996; Alvey 2006). These stresses and
disturbances can result in habitat loss and isolation.
Habitat loss and isolation from land development poses a serious threat to the
biodiversity of urban forests. The conversion of continuous forest habitat into discrete habitat
fragments reduces biodiversity by creating edge habitats, decreasing habitat size, and/or isolating
habitats. Research suggests that edge habitats can create different microclimatic conditions e.g.
higher wind velocities, warmer temperatures, and lower moisture along the edges of forest.
These conditions often penetrate multiple meters into the forest. These micro changes in climate
can further reduce the size of the already fragmented habitat and create opportunities for invasive
species (Collinge 1996).
The size and shape of a habitat remnant are crucial for determining the area of interior
habitat available for animal and plant species that are dependent on continuous habitat.
Rectangular and smaller fragments tend to have less interior habitat available. This reduces the
biodiversity within these remnant patches and could potentially lead to local species extinction
(Collinge 1996). Conversely, larger and square remnant patches have more interior habitat and
less edge habitat that allow for greater biodiversity in these fragments (Collinge 1996).
15. 9
Climate change poses a potential threat to urban areas and their forests and must be
assessed when considering the conservation of urban forest and biodiversity. Patterns of
warming have become more prevalent in cities and temperate zones of the world. These patterns
have created observable poleward and elevational shifts in certain species in response to
warming climates (Wilby and Perry 2006; Hunter 2011). Warming climate patterns have also
induced phenological shifts in certain species (Wilby and Perry 2006; Hunter 2011). These
movements and phenological shifts of species can reduce biodiversity in urban forests because
warmer and drier climates can potentially increase the amount of disease and pests present within
an area (Wilby and Perry 2006). A specific example of pest abundance due to warming winters
is the increased presence of the EAB (Crosthwaite et al. 2010). Research has shown EAB
prepupae to be freeze-intolerant, hence warmer winter temperatures increase survival rates of
this particular species of insect. An abundance of EAB presence endangers the ash trees within
urban forests, thus reducing biodiversity and tree canopy cover (Crosthwaite et al. 2010).
Research on fostering biodiversity and social-ecological system resilience in light of biodiversity
loss and climate change in urban environments have brought about different management and
adaptive strategy plans to mitigate these effects in urban forests.
Biodiversity Management
Management and planting regime strategies for urban forests should be designed to foster
and/or maintain ecological resilience to preserve or increase ecosystem health. Ways to
incorporate this concept is to increase functional and response diversity within urban forest
ecosystems (Chapin lll et al. 2009; Hunter 2011). Other concepts to consider when designing
urban forest planting regimes are the plasticity of specific tree species and structural diversity
16. 10
(Hunter 2011). When considering specific species of trees to plant when promoting diversity
and resilience native species are typically preferred, but non-native or cultivar species that are
not invasive should also be considered in the planting regime (Alvey 2006). Developing an
urban forest planting regime is important for fostering resilience and biodiversity of a social-
ecological system. Humans play a large role in social-ecological systems, thus human tree
values should be taken into consideration when designing a feasible urban forest planting regime
(Dywer et al. 1991; Chapin lll et al. 2009). Once urban forest plans are implemented it is
important to manage the entire social-ecological system as a whole and not just the urban forest
aspect of the plan (Chapin lll et al. 2009).
Methodology
For this project, a methodology was developed to determine the estimated biodiversity
values throughout Clinton’s urban forest using its tree inventory data. Understanding the current
tree inventory and the estimated biodiversity values are vital to analyzing the state of Clinton’s
urban forest in terms of resilience and sustainability. To enhance the understanding of Clinton’s
urban forest, a multi-step process was developed.
To interpret the biodiversity of Clinton’s urban forest, a tree inventory was first
completed in the fall of 2015. The inventory involved the surveying of private and public trees
within Clinton. Semi-randomly selected city blocks were surveyed for private tree information
and the public trees were surveyed in total by the Davey Resource Group.
To complete the necessary biodiversity calculations, the Shannon Diversity Index was
chosen as the biodiversity metric. The Shannon Index is a commonly used calculation that
measures diversity based on the species richness and evenness within an area and is calculated
17. 11
by 𝐻′ = − ∑ 𝑅
𝑖=1 𝑝𝑖 ∗ (𝑙𝑛 ∗ 𝑝𝑖), where 𝑝𝑖is the proportion of individuals belonging to the ith
genus and R is the genus richness (Tramer 1969). To prevent misrepresentation of the
calculated diversity values, genus richness and evenness were used instead of species richness
and evenness. This prevents the diversity data from appearing more diverse than it actually is by
removing the weight on the presence of multiple species located within the same genus.
In order to successfully implement the Shannon Index, the city of Clinton was divided up
uniformly into 60 analysis areas (Figure 2). The Shannon index was calculated and then
assigned for any of the areas containing tree data. These Shannon Index values were input into
ArcGIS, where spatial interpolation was used to generate estimated biodiversity values based on
neighboring area values for any areas with insufficient data.
18. 12
Figure 2: A visual representation of the 60 analysis areasused to generate individual Shannon Index
values. Map by Jacob Smith.
19. 13
Figure 3: This map displaysthe semi-randomly surveyed private trees in Clinton’s urban forest. Map by author.
20. 14
Figure 4: This map displays the locationsof all of the public trees surveyed in Clinton. Map by author.
21. 15
Results
The Shannon values range from 0.0-2.66. The Shannon diversity scale itself ranges from
0.0-3.5, where 0.0 represents an absolute lack of biodiversity, or monoculture, and 3.5 exhibits
an evenly-spaced and a high level of biodiversity within an area. A total of 13 areas had a
Shannon Diversity of 0.0. This is not due to a monoculture presence in these areas and instead,
are a result of a lack of private tree data (Table 1) .
All of the trees that were surveyed in Clinton were condensed into their common name
genus (Appendix 1). Tree genus was selected over species type because using tree species would
give a false sense of diversity in areas with multiple species that fall under the same genus.
Overall, 6,807 trees were surveyed falling under 68 different genera. The gamma diversity of
Clinton is 2.82. This value depicts Clinton’s urban forest as diverse, but the top ten genera make
up 76 percent of the surveyed trees. The maple genus made up 29.4 percent of all surveyed
trees in Clinton, indicating a maple dominance in the city (Appendix 1).
The age structure of Clinton’s surveyed urban forest is fairly uneven with a majority of
its trees being mature. Planting efforts appear to have been focused on in northeastern Clinton as
there are a large number of younger trees in this region. Southeastern Clinton, conversely, is
dominated by mature trees. Areas 17, 18, 46, and 55 are sections of structural concern as these
are public areas where a majority of their trees are mature (Figure 2; Figure 6).
A majority of the surveyed trees in Clinton are located on the eastern side of town, yet
these areas have a low diversity index and a mature tree age structure (Figure 5; Figure 6).
Despite these low Shannon values, these eastern urban areas yield higher levels of biodiversity
than the western semi-rural areas. Areas 49, 50, 46, and 47 are of concern as they are located in
22. 16
a downtown area with many trees, but they have poor Shannon values of 2.06, 2.03, 1.64 and
2.03. Areas 21 and 16 have the highest Shannon values 2.66 and 2.65 and are evidence that
higher levels of diversity are attainable in the urban areas of Clinton (Figure 5; Table 1).
Table 1: Shannon diversity Index foreach of the 60 analysisareas in Clinton, IA. JJJ Represent areas of
Concern where ABC represent areas of higher biodiversity.
Analysis
Area
Shannon's
Diversity
Analysis
Area
Shannon's
Diversity
Analysis
Area
Shannon's
Diversity
Analysis
Area
Shannon's
Diversity
1 0 16 2.65 31 0 46 1.64
2 1.59 17 2.47 32 1.9 47 2.03
3 1.66 18 2.13 33 1.76 48 2.38
4 1..96 19 0 34 1.05 49 2.06
5 2.16 20 0 35 1.87 50 2.03
6 0 21 2.66 36 0 51 2.5
7 0 22 2.38 37 2.12 52 2.4
8 1.75 23 0 38 0 53 1.27
9 1.72 24 2.12 39 1.9 54 1.67
10 0 25 1.51 40 1.24 55 2.22
11 1.8 26 1.09 41 1.68 56 1.42
12 2.4 27 1.61 42 1.16 57 2.39
13 1.59 28 0 43 1.5 58 2.15
14 2.18 29 0 44 2.46 59 1.89
15 1.91 30 0 45 2.5 60 2.56
23. 17
Figure 5: This map exhibits the tree diversity and estimated tree diversity in terms of the shannon diversity. Green represents
areas of low levels of biodiversity and red represents areas with higher levels of diversity. Areas outlined in magenta are areas
of biodiversity concern, where areas outlined in white are areas with a fair amount of diversity.
24. 18
Figure 6: This map displaysthe locationsand sizes of each surveyed tree in Clinton’s urban forest canopy.
25. 19
Discussion
The map in Figure 5 reveals the Shannon Diversity for areas of Clinton’s urban forest.
The higher levels of biodiversity in the urban forest occur on the eastern side of Clinton where a
majority of Clinton’s public trees are located. The southeastern portion of Clinton along
highway 30 holds the areas of greatest diversity with the highest recorded Shannon value there
being 2.66 in area 21 (Table 1; Figure 5). Ironically enough, these areas along highway 30 were
planted at roughly the same time, creating an uneven age structure (Figure 6). Despite the higher
levels of diversity, the trees in these areas are unevenly aged and when these trees reach maturity
they will be less resilient to pests, disease, and death due to old age, putting these areas at risk of
mass canopy loss in a short period of time.
Figure 5 is misleading and indicates that values such as 2.66 in area 21 are high.
However, the Shannon Diversity Index is on a scale from 0.0-3.5 and is sensitive to changes in
the hundredths place. Analysis of Figure 5 and Appendix 1 make it evident that Clinton has a
tree diversity issue in its urban forest due to a maple dominance and an uneven distribution
amongst tree genera present within Clinton. The top ten tree genera in Clinton account for 76
percent of the urban forest canopy (Appendix 1).
Specific areas of biodiversity concern indicated by Figure 5 and Table 1 were areas 46,
47, 49, 50, and 55. These areas are highly visible and each contain a large number of trees, but
have low levels of biodiversity within them. This makes them vulnerable to loss of biodiversity
and the degradation of other ecosystem services through exogenous and endogenous stresses,
making these priority areas for management.
26. 20
Analysis of Figure 6 revealed that Clinton has an unevenly aged urban forest, with the
majority of its trees being mature in age. Areas in northeastern Clinton have a large number of
younger trees, where in southeastern Clinton, a majority of the trees are mature in age. This
uneven age structure throughout Clinton places specific sections such as areas 17, 18, 46, and 55
at risk of severe canopy loss. These areas are highly visible to the public and contain a large
amount of mature trees, making them more vulnerable to pests, diseases and death in a short span
of time. Significant canopy loss in these areas could severely damage the aesthetics and the
ecological processes occurring here. Like areas 46, 47, 49, 50, and 55, these are priority
management areas.
The areas of immediate management concern are areas 46 and 55. These sections both
have low levels of biodiversity and are dominated by mature-aged trees. Area 46 is a downtown
area that is highly visible to the public. Any mass loss of canopy coverage in this area would
have detrimental aesthetic effects and would result in the degradation of critical ecological
processes. Area 55 is a densely wooded section in Eagle Point Park. This area is also visible to
the public and a significant loss of trees here would result in forest fragmentation, leading to
further loss of biodiversity and the depreciation of area aesthetics.
The spatial diversity and tree inventory data acquired as a result of this study are critical
because they provide information on areas of diversity concern and allow for the development of
an urban forest planting regime that fosters and restores diversity and resilience to specific areas
of Clinton’s urban forest.
Clinton is not the only area in the Upper Mississippi River Valley suffering from a maple
dominance and an uneven forest age structure. River floodplain forests throughout the Upper
27. 21
Mississippi River Valley have seen a shift from heliophilic oak and hickory forests to mesophilic
maple dominated forests (Nowacki and Abrams 2008; Romano 2010). The findings observed in
this study appear consistent with research on the mesophication of forests in the Eastern U.S. and
in the Upper Mississippi River floodplain forests. As forests in these regions become more
dominated with shade-tolerant species, they are more vulnerable to reductions in diversity and
resilience (Nowacki and Abrams 2008; Romano 2010). The methods in this study can possibly
contribute to the way that forests in the Eastern U.S. and Upper Mississippi River Valley are
managed by identifying areas of biodiversity and age structural concern. As these areas are
identified, forest planting regimes can be developed to improve the resilience of these regions
while also maintaining areas with significant amounts of biodiversity and age diversity.
A significant limitation of this study was the overall lack of private tree inventory data
(Figure 3). Figure 5 identifies many areas with a Shannon Diversity of 0.0 or values below 1.0.
These values only occur due to the lack of private tree information available in the absence of
public tree data. While Clinton’s urban forest does have tree diversity issues, this lack of private
tree information makes the diversity of Clinton’s urban forest appear worse than it actually is.
To build upon this study, more effective methods of surveying private yard trees need to be
developed, along with the public education on the importance of tree identification in hopes to
improve the Clinton’s current urban forest inventory.
Clinton’s urban forest is suffering from a lack of biodiversity and tree age diversity. No
analysis areas had a Shannon value greater than 2.66 and 76 percent of all the surveyed trees in
Clinton were classified under the top ten tree genera as well as a large portion are mature in age,
creating an uneven age structure of trees throughout Clinton (Table 1; Appendix 1; Figure 6).
28. 22
Due to a lack of private tree information this plan should look to improve conditions within the
public tree realm (Figure 4). To address these issues, adaptive management techniques will be
need to be taken. These techniques should be determined and taken by an agency and the
stakeholders of Clinton to develop a planting regime that incorporates the following: Increasing
functional redundancy and response diversity and planting for species plasticity and structural
diversity within Clinton’s urban forest, all while taking into consideration the human values on
trees. These are all aspects that a planting regime should have in order to foster the biodiversity
and resilience within Clinton’s social-ecological system (Chapin lll et al. 2009).
29. 23
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