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Anna L. Johnson1, Daniel J. Bain2, Erin M. Copeland3, and Christopher M. Swan1 1Department of Geography and Environmental Systems, UMBC, Baltimore, MD, 21250; 2Department of Geology and Planetary Science, University of
Pittsburgh, Pittsburgh, PA, 15260; 3Pittsburgh Parks Conservancy, Pittsburgh, PA, 15219!
Acknowledgments Many thanks to the Pittsburgh Parks Conservancy for making available this data, the UMBC IGERT program, grant# for funding this internship experience, and field assistants MT and KG.
Conclusions/Future Directions"1. The average number of reported invasive
species in plots decreased significantly after one year of EcoSteward management. There was no additional decrease seen with additional years of management.
2. Resurveys of a subset of plots showed a consistent increasing trend in non-invasive species diversity in plots with additional years of management.
3. Species varied in their response to removal, but the only significant difference between functional groups was between small and med. seeded, and between annuals and biennuals.
Assessing the ecological results of environmental stewardship programs is an important and often over-looked component of stewardship groups efforts, due to time, money, and expertise limitations. These findings suggest that there is substantial potential to improve urban ecosystems through such management effort.
"
Literature cited"1. Grimm, Nancy B. et al. “Global Change and the Ecology of
Cities.” Science 319 (2008) : 756-760. !2. Williams, Nicholas S.G. et al. “A Conceptual Framework for
Predicting the Effects of Urban Environments on Floras.” Journal of Ecology 97 (2009) : 4-9.!
3. Chiesura, Anna. “The Role of Urban Parks for the Sustainable City.” Landscape and Urban Planning 68 (2004) : 129-138. !
" For further information"Please contact Anna Johnson, annaj1@umbc.edu!"
Volunteer urban environmental stewardship: "An effective way to manage plant communities in city parks"
!
Introduction" Urban areas are increasingly viewed as diverse ecosystems that provide a wide array of valuable ecosystem services1,2. Urban parks and greenspaces are often city residentsʼ primary access to nature, and provide a valuable space for recreation and relaxation3. Urban parks, however, tend to be particularly vulnerable to invasion by aggressive non-native plant species. These invasive species can significantly reduce plant community diversity and disproportionately harm rarer native plant species. Many cities rely on programs that recruit and train volunteer citizens to perform environmental stewardship work, including invasive species removal. The extent to which these programs are ecologically successful, however, is rarely assessed. !!The Urban EcoStewards program is an initiative of a group of
Pittsburgh, PA nonprofits, coordinated by the Pittsburgh Parks Conservancy, with the goal of “building sustainable urban ecosystems through citizen stewardship.” The objective of this project was to assess the success of the Urban EcoStewards program in encouraging diverse, native communities of plants in Pittsburghʼs urban parks. "!
Materials and methods Volunteer-reported data were analyzed for trends in
invasive species presence/absence with management duration (measured in years of EcoSteward monitoring) and plant functional traits in 81 EcoSteward plots. Additional plant community surveys, using a line-transect intercept approach, were performed in a subset of 6 EcoSteward plots during the summer of 2010. These plots were selected to be forested and to span a management gradient measured in years of stewardship. Data was collected to answer the following questions: Does the Urban EcoStewards program: "1. reduce the prevalence of invasive plant species in
EcoSteward plots?"2. increase native plant species diversity in
EcoSteward plots?"And, "
3. is small-scale invasive species removal more successful for some species than others?
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0
20
40
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120
Snyder's point, slope Forbes Bridge Wetland 2
Yarrow Hill Canopy Gap Snyder's point BB#2 BB#4
Rel
ativ
e de
nsity
of h
erba
ceou
s cov
er
Relative Density of Invasive vs. Non-Invasive Herbaceous Plants along a Gradient of Management in UES Plots
Invasive
Noninvasive
n=79 n=48 n=36 0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0.0014
1 Year 2 Years: 3-5 Years Nor
mal
ized
Num
ber o
f Spe
cies
per
Plo
t Recorded Years of Ecosteward Management Plot has Received
Average Number of Invasive Species Per Plot, Normalized by Plot Area, for plots experiencing
different lengths of management
Reference, no UES Management
3 yrs recorded management, inactive
4 yrs management, inactive
3 yrs recorded management, active
3 yrs recorded management, active
5 yrs of management, active
3 yrs recorded management, active
Management Gradient"
1. Q: Does the Urban EcoStewards program reduce the prevalence of invasive plant species?"
1: A: Yes—after at least two years of management, there is a significant reduction in the number of observed invasive plant species that occur in EcoSteward-managed plots!
2. Q: Does the Urban EcoStewards program increase non-invasive plant species diversity?"
2. A: Yes—based on a small subset of plots spanning a management gradient, there does appear to be an increasing trend in native species diversity and a decreasing trend in invasive species diversity, in managed, forested Urban EcoSteward plots. !
Confidence intervals are 95%!
Removal success* vs. functional traits!
0 20 40 60 80 100 120
0.10
0.15
0.20
0.25
0.30
0.35
0.40
number of plots species occurs in
prop
. of y
ears
it w
as s
ucce
ssfu
lly re
mov
ed
ARSPALPE
LYSA
LOMAPOPE
ACPL
CIAR
SEVA
AEPO
POCU
ARVU
BETH
RHSC
ROMULISPHEHE LOJA
CEOR
AMBR
AEAL
Removal success vs. plot occurrence, by speciesRemoval success* vs. plot occurrence, by
species!Common Name CODE Burdock ARSP Garlic mustard ALPE Purple loosestrife LYSA Bush honeysuckle LOMA Mile a minute POPE Norway Maple ACPL Canada Thistle CIAR Crown Vetch SEVA Goutweed AEPO Japanese knotweed POCU Mugwort ARVU Japanese barberry BETH Jetbead RHSC Multiflora rose ROMU Privet LISP English ivy HEHE Japanese honeysuckle LOJA Oriental bittersweet CEOR Porcelainberry AMBR Native grape VISP Tree of Heaven AIAL !
3. Q: Is small-scale invasive species removal more successful for some species than others?
3. A: Yes—Both garlic mustard and burdock were extremely common in the EcoSteward plots and also were rarely removed successfully. Species such as jetbead and oriental bittersweet, however, were rarer in plots and also removed successfully more often. There were, however, no strong relationships between removal success and the measured functional traits, except for a significant difference between small and medium-seeded plants, and annuals and biennuals.!
Acknowledgments This research was supported by the National Science
Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) ʻWater in the Urban Environmentʼ program (Grant No. 0549469). Many thanks to the Pittsburgh Parks Conservancy (PPC) for hosting the internship and making the data available, to PPC’s Adam Fedyski’s organizational help, and to field assistants Margaret Tully, Heather Goodwin, and Kurt Garrison.
Notes: *”Removal Success” calculated as the percentage of times that a species was present in a plot and absent the following year. :
Nonclonal Clonal
0.05
0.10
0.15
0.20
rem
oval
suc
cess
annual biannual perennial
0.05
0.10
0.15
0.20
small seeds large seeds
0.05
0.10
0.15
0.20
not animal-dispersed
0.05
0.10
0.15
0.20
rem
oval
suc
cess
not wind-dispersed
0.05
0.10
0.15
0.20
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