Invasive plants in cities: A historical perspective based on the flora of

Indianapolis

Rebecca W. Dolan

Friesner Herbarium and Center for Urban Ecology, Butler University

Result of search on “urban” using Google Images

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@Aditya Kok/Deamstime.com

@Aditya Kok/Deamstime.com

@Aditya Kok/Deamstime.com

@Aditya Kok/Deamstime.com

@Aditya Kok/Deamstime.com

@Aditya Kok/Deamstime.com

6 Challenges of the Urban Environment

• Distinct soils

• Altered hydrology, impervious surfaces

• Heat islands

• Disturbance regime, perpetual disequilibrium

• Loss of pollinators and seed dispersers

• Habitat fragmentation

13th largest city in the US

Population = 900,000Density = 857/km2

98% forested 1820s76% beech-maple upland forest

Late 1990s 13% forested

Northern 2/3 of state covered byglaciers ca. 10,000 years ago

Tipton Till Plain Natural Region

Land Use:1922 80% ag1953 72%1990 18%

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Table 1 Floristic quality data comparing historical records of Marion County, Indiana with

recent inventories

Historical Recent

Total Species 706 698

No. Native Species 563 509

Percent Non-native 20.3 27.1

Native Mean C 4.2 4.0

Native Mean C With Non-native 3.4* 2.9*

Native Mean Wetness 0.2 0.4

* significantly different at p<0.01 based on non-parametric T-test using Wilcoxon rank sum test

with continuity correction.

Dolan et al. 2011. Documenting effects of urbanization on flora using herbarium records. Journal of Ecology 99:1055-1063

In Indy: 69/120 on official invasives list = 57.5%

69/700 total species = ~ 10% invasives

67%

12%

20%

1%

Invasive Rank

High

Caution

Medium

Low

Indy Invasives

67%

12%

20%

1%

Invasive Rank

High

Caution

Medium

Low

Indy Invasives

36%

26%

12%

20%

6%

Origin

Asia

Eurasia

Eurasia and No. Africa

Europe

Other

67%

12%

20%

1%

Invasive Rank

High

Caution

Medium

Low

Indy Invasives

36%

26%

12%

20%

6%

Origin

Asia

Eurasia

Eurasia and No. Africa

Europe

Other

18%

6%

7%

12%

53%

4%

Use or Cause of Introduction

Accidental/unknown

Erosion, wildlifefood/cover

Food/Medicinal

Forage

Ornamental

Other

19%

35%

46%

Time First Documented

1890s 1940 later

Indy Invasives

G.W. Wilson. “The flora of Hamilton and Marion Counties, Indiana.”

G.W. Wilson. The flora of Hamilton and Marion Counties, Indiana.

Canada thistle rare

Queen Anne's lace very common

Creeping Charlie very common

Sweet clover common

Bouncing bet common

Tree-of-heaven very rare

Periwinkle becoming common

2008

53 sightings in Marion County reported to Edd-Maps since 2013

50+ specimens of listed invasives collected or directed by be collected

by IndyParks Land Stewardship Office staff

Scientific Name Historical Recent

Herbaceous

Alliaria petiolata Garlic mustard 0 x

Artemesia vulgaris Mugwort 0 x

Carduus nutans Musk thistle 0 x D

Centaura stoebe Spotted knapweed 0 x

Cirsium arvense Canada thistle x x

Cirsium vulgare Bull thistle x x

Clematis terniflora Sweet autumn clematis 0 x

Conium maculatum Poison hemlock 0 x D

Convolvulus arvense Field bindweed x x

Coronilla varia Crown vetch x x

Cynanchum louiseae Black swallow-wort x x

Daucus carota Queen Anne's lace x x

Dioscorea polystachya Chinese jam 0 x D

Dipsacus follonum Common teasel x x

Dipsacus laciniatus Cut-leaved teasel x x

Euphorbia escula Leafy spurge x x

Glechoma hederacea Creeping Charlie x x

Hesperis matronalis Dame's rocket x x

Humulus japonicus Japanese hops 0 x D

Hypericum perforatum St. John's wort x x

Iris pseudoacorus Yellow iris 0 x D

Kummerowia stipulacea Korean lespedeza 0 x D

Kummerowia striata Striate lespedeza x x

Lespdeza cuneata Sericea lespedeza 0 x

Lythrum salicaria Purple loosestrife x x

Melilotus officinale Sweet clover x x

Microstegium vimineum Japanese stiltgrass 0 x

Myriophyllum spicatum Eurasian watermilfoil 0 x D

Najas minor Braided naiad 0 x

Pastinaca sativa Wild parsnip x x

Phalaris arundinacea Reed canarygrass x x

Phragmites australis Common reed x x

Potamogeton crispus Curly-leaved pondweed x x

Ranunculus ficaria Lesser celandine 0 x

Saponaria officinalis Bouncing bet x x

Schedonorus arundinaceus Tall fescue x x

Sorghum halepense Johnson grass x x

Torilis japonica Japanese hedge parsley 0 x D

Typha angustofolia Narrow-leaved cattail x x

Vicia cracca Cow vetch x x

Historical Recent

Trees

Acer platanoides Norway maple 0 x

Ailanthus altissima Tree-of-heaven x x

Alnus glutinosa Black alder 0 x D K

Morus alba White mulberry x x K

Pyrus calleryana Callery pear 0 x

Ulmus pumila Siberian elm 0 x

Woody vines

Ampelopsis brevipendunculata Porcelain berry 0 x

Celastrus orbiculata Oriental bittersweet 0 x

Hedera helix English ivy 0 x

Lonicera japonica Japanese honeysuckle 0 x D

Shrubs

Berberis thunbergii Japanese barberry x x K

Elaeagnus angustifolia Russian olive 0 x

Elaeagnus umbellata Autumn olive 0 x

Euonymus alatus Burning bush 0 x

Euonymus fortunei Winter-creeper 0 x

Fallopia japonica Japanese knotweed 0 x

Frangula alnus Glossy buckthorn 0 x

Ligustrum obtusifolium Blunt leaved privet 0 x D

Ligustrum vulgare Common privet 0 x D

Lonicera maackii Amur honeysuckle 0 x

Lonicera morrowii Morrow's honeysuckle 0 x K

Lonicera tatarica Tatarian honeysuckle 0 x D K

Lonicera × bella Bell's honeysuckle 0 x K

Rhamnus cathartica Common buckthorn 0 x D K

Rhodotypos scandens Jetbead 0 x

Rosa multiflora Multiflora rose 0 x D K

Rubus phoenicolasius Wine raspberry 0 x D

Viburnum opulus var. opulus Highbush cranberry 0 x

Vinca minor Periwinkle x x

Minutes of the Indianapolis Parks Board – Kessler Plan plants

Species Common Name total %

Quercus macrocarpa Bur oak 774 6.4

Quercus bicolor Swamp white oak 745 6.1

Cercis canadensis Redbud 592 4.9

Amelanchier sp. Service berry 520 4.3

Quercus rubra Red oak 416 3.4

Quercus muehlenbergii Chinquapin oak 415 3.4

Gymnocladus dioicus Honey locust 407 3.3

Liquidambar styraciflua Sweetgum 387 3.2

Juniperus virginiana Red cedar 383 3.1

Acer saccharum Sugar maple 377 3.1

Ulmus americana American elm 368 3.0

Nyssa sylvatica Black gum 336 2.8

Acer rubrum Red maple 323 2.7

Amelanchier sp. Service berry species 319 2.6

Quercus sp. Oak species 255 2.1

Plant Native Species

Trees planted in Indianapolis by Keep Indianapolis Beautiful 2008 – 2011

Dolan, R.W. 2015. Two hundred years of forest change: effects of urbanization on tree species composition and structure. Arboriculture and Urban Forestry 43:136-145.

5 Biggest Problem Species in Indy

• Current1. – Euonymus fortunei

- Lonicera maackii, etc.

3. - Alliaria petiolata

4. - Celastrus orbiculatus

5. - Euonymus alatus

- Lonicera japonica

- Pyrus calleryana

5 Biggest Problem Species in Indy

• Current1. – Euonymus fortunei

- Lonicera maackii, etc.

3. - Alliaria petiolata

4. - Celastrus orbiculatus

5. - Euonymus alatus

- Lonicera japonica

- Pyrus calleryana

• Emerging1. - Fallopia japonica

- Microstegium vimineum

- Pyrus calleryana

4. - Berberis thunbergii

5. - Clematis terniflora

- Euonymus alatus

http://reconnectingtoourwaterways.org/

Asian bush honeysuckle links to ROW elements

• Economics – negatively affected property values and economic investment; properties near Fall Creek were not benefiting from their location near this potential asset

• Education – local neighborhood citizens were under-aware of the issues surrounding invasives and did not know how the control invasives

• Well-being – caused safety concern due to overgrowth of shrubs that retain their leaves through a long growing season, provide potential cover for miscreants

Asian bush honeysuckle links to ROW elements

• Aesthetics- decreased natural beauty due to monoculture and blocking natural view to waterway, view-shed (opinion based- some people liked how honeysuckle looked and were upset by it being removed, assuming any green vegetation in the city was a good thing)

• Connectivity – physically blocked people’s ability to see and access the waterway and therefore the connection of the Fall Creek neighborhood to the waterway system of the city

• Ecology- impacted ecological form and function by reducing understory diversity, out-competing native herbaceous plants, shrubs seedlings and tree saplings, while reducing overstoryproductivity

Outputs of 2012 LDOS

• Over 2,000 volunteers removed over 760 m3

of Amur honeysuckle from 30 acres of land along Fall Creek

• Twelve partner organizations included private donors, corporate, city of Indianapolis, non-profit, and universities contributed over 1.1 million dollars in cash and services

In urban settings, invasives, especially woody shrubs escaped from

cultivation

• have negative impacts on cultural ecosystem services that may be greater than their ecological impacts in cities’ highly disturbed ecosystems

In the UK:

Japanese knotweed is not a health hazard but can cause extreme stress and anxiety if people are unable to secure mortgage and/or buy sell properties due to its presence. • It can cause a lot of arguments and disagreements between neighbours and land owners that may result in legal action.

Thank youThank you!