A Sandy and Swampy Urban Island: A summary of ecological problems and solutions at Sand Ridge Nature Center
Introduction
Since September of 2014, I have been serving the Forest Preserves of Cook County as a naturalist at a Chicago-area suburban nature education center situated in a 300 acre urban nature preserve. Sand Ridge Nature Center (SRNC), which geographically straddles the border of South Holland and Calumet City in Illinois, is named for the ancient high Toleston Beach Ridge that formed as the water levels of Lake Michigan began receding after the end of the last major ice age (figure 1) (Forest Preserves of Cook County, 2016). The former 6,000 year-old beach ridge is still partially intact in several forest preserves, with one the longest remaining stretches on the northern end of the nature center property along Michigan City Road (figure 2). The present extent of Sand Ridge Nature Center includes all of the land north of U.S. Highway 6 to Michigan City Road, then from Paxton Avenue east to Illinois Highway 83 (Torrence Avenue) along the municipal boundaries of South Holland and Calumet City.
Since the dawn of Northern Illinois' pioneer settlement around 1810, the surrounding landscape has undergone numerous land-use changes, historically consisting of primarily oak woodlands mixed with lowland forests which were then converted to agriculture, then onward to industry and urban commercial development (Schoon, 2003). As such, the region has endured numerous forms of ecological disturbance and environmental degradation. The ecological problems of SRNC can be conceptualized into 5 general categories, which will be briefly summarized in this blog two part blog post: (1) habitat isolation; (2) near or total extirpation of certain flora and fauna species; (3) invasive species; and (4) land and air pollution. Socioeconomic problems have indirectly contributed to the nature center's management issues, as the region's demographics are largely comprised of less educated and less environmentally aware groups of people, and therefore (5) the social-environmental problems of SRNC will be briefly discussed. Finally, a summary of the more recent restoration efforts by the Forest Preserve District and others will be showcased as the aforementioned chronic problems are addressed by its constituents.
It should be noted that SRNC does not exist in a vacuum but is in fact part of a larger network of forest preserves and other natural areas that are geographically distributed across Cook County, Illinois. Nonetheless, I will place a spotlight almost exclusively on SRNC since it is one of the few managed natural areas in the region with developed spaces for education programs and exhibits that facilitate an experience for visitors and other members of the public.
Habitat Isolation
Famed ecologists Edward O. Wilson and Robert MacArthur (1967) conceptualized the local loss of species and ecosystem degradation through their island biogeography model which compared natural areas isolated by human activities (urban development, agriculture, etc.) as islands in a sea with respect to their ecosystem functions and species population dynamics. Wilson and MacArthur concluded that islands that were relatively large in size were often more stable in regards to species composition, and often served as source populations that could colonize other geographic areas (or other islands). Smaller islands that are close by to larger islands could presumably gain species populations via immigration from nearby source populations, while smaller islands that are far away from mainlands were much more vulnerable to species loss due to their distant proximity to a source population. Wilson and MacArthur argued that natural areas isolated by human activities function on an island biogeography dynamic, with smaller and fragmented natural landscapes undergoing species loss and degradation as humans modify the surrounding landscape. Sand Ridge Nature Center and nearby adjoining forest preserve tracts are, for the most part, surrounded on all four sides by urban and suburban development, including the presence of River Oaks Mall, a large and aging shopping center located just outside the boundaries of SRNC and the Green Lake forest preserve properties (see figure 3).
The isolated condition of SRNC might be the reason for the absence or lack of abundance of some flora and fauna species, as discussed below. It also also led to the "edge-effect" where there is less interior habitat and more transitional areas such as scrubland that favor generalist species of plants and animals such as green ash (Fraxinus pennsylvanica) or Eastern Cottontail rabbits (Sylvilagus floridanus).
Species population depletion
Bears, wolves, and other large tertiary predators were extirpated from northern Illinois by the end of 19th century (Schoon, 2003). Although there have been some anomalous sightings of large predators in recent years (Holtz, 2012), lack of suitable habitat has prevented recovery of most large predator populations. Therefore the scarcity of predatory wildlife has benefited some large herbivore populations such as white-tailed deer (Odocoileus virginianus) (see figure 4). White-tailed deer and other animals have also benefited from increased suitable habitat, particularly edge habitat, as mentioned above.
More recent species population depletion includes those of reptiles and amphibians. At present date, SRNConly has 7 of 13 known species of amphibians in Cook County and only 5 of 9 reptile species (Anton, 1999). Cook County overall has lost 13 additional species of reptiles and amphibians since 1940 (Anton, 1999). One plausible explanation for this sharp drop in reptile and amphibian diversity is the large-scale fragmentation of natural lands in the region, with enhanced urbanization taking place during the 1970s into the 1990s with the development of the River Oaks Mall shopping center at the Bishop-Ford Freeway (Interstate 94). Impacts to water quality from accelerated run-off may also be a confounding factor (discussed below).
Bird diversity has declined in recent years, although not as dramatically as other wildlife groups. The Passenger Pigeon (Ectopistes migratorius) became extinct by 1908 (Schoon, 2003) alongside the Ivory-Billed Woodpecker (Campephilis prinicpalis), which may have historically been present in the region. Bald Eagles and Osprey are uncommon sightings but their populations have rebounded in recent years across northern Illinois and are occasionally observed at SRNC. As of this writing, over 110 species of birds have been observed within the boundaries of Sand Ridge Nature Center (eBird, 2016).
Changes in insect and other invertebrate diversity has yet to be formally assessed. Sand Ridge Nature Center is just within the range of the federally endangered Karner Blue Butterfly (USFWS, 2015), although no recent sightings have been documented.
All species of Ash trees (Fraxinus spp.) are in a sharp decline due to the accidental introduction of the Emerald Ash Borer beetle (Agrilus planipennis) (figure 5).
White Pine (Pinus strobus) and Northern White Cedar (Thuja occidentalis) were mostly likely present during pre-Settlement times as well as Jack Pine (Pinus banksiana) but are now largely absent with the exception of some replanted specimens. Various other orchids, ferns, and other herbaceous plants, forbes, and woody plants might have either been extirpated or their populations severely reduced, but a full-scale assessment of vegetation changes since pre-settlement times is difficult to perform.
Invasive Species
Habitat fragmentation and degradation leading to species population decline has been exacerbated by non-native, invasive species.
Since the beginning of the 19th century, about 150 introduced plant species have become invasive and form monocultures in otherwise diverse ecosystems (e.g. prairies), generally becoming well established in areas with high disturbance (NRCS Illinois, 2016). SRNC's most problematic invasive plants include European Buckthorn (Rhamnus cathartica), Glossy Buckthorn (Frangula alnus), Japanese Bush Honeysuckle (Lonicera spp.), Canada Thistle (Circium arvense), Garlic Mustard (Allaria Petiolata, see figure 6), Oriental Bittersweet (Celastrus orbiculatis), Lilly-of-the-valley (Convallaria majalis), Purple Loostrife (Lythrum salicaria), Common Reed (Phragmites australis), and Cattail (Typha spp.). Purple Loosestrife, Common Reed, and Cattail presently dominate at least 70% of Sand Ridge Nature Center's wetland areas. There may be other invasive plant species established at Sand Ridge Nature Center, but they have not been formally documented nor observed. Nature center staff have been keeping an informal rolling inventory of the emergence of invasive plant species on iNaturalist:
http://www.inaturalist.org/projects/invasive-plant-species-of-sand-ridge
SRNC also has some invasive, non-native animal species present. House Sparrows (Passer domesticus), originally native to Europe, compete with native bird species such as Eastern Bluebirds (Sialia sialis) for habitat and nesting sights, although bluebirds and other native birds do not appear entirely inhibited by the presence of house sparrows. European Starlings (Sturnis vulgaris), and House Finches (Haemorhous mexicanus) are present as well, but their impacts on Sand Ridge Nature Center's birds do not appear to be substantial. A long-term inventory of Sand Ridge Nature Center's birds (breeding and migratory) can viewed on eBird:
http://ebird.org/ebird/GuideMe?step=saveChoices&getLocations=hotspots&parentState=US-IL&bMonth=03&bYear=2016&eMonth=12&eYear=2016&reportType=location&hotspots=L152713&continue.x=85&continue.y=15
There might also be non-native invasive fungi and insects, but no formal inventory or observations have been made regarding the presence of invasive invertebrates or fungi with the exception of the invasive Emerald Ash Borer beetle mentioned earlier in this blog post. Cook County has done formal inventories of mosquito populations at Sand Ridge Nature Center, but at the time of this writing their data is not within accessible form.
Invasive species most frequently become established in areas with high levels of landscape disturbance. Generally, non-native invasive plants receive the most attention from land managers with respect to control and mitigation of their populations. However, native plants that thrive in a disturbed environment can also become invasive or overabundant, leading to biodiversity loss and habitat degradation. These "native invasives" at Sand Ridge Nature Center include Canada Goldenrod (Salidago canadensis), Tall Goldenrod (S. altissima), False Buckwheat (Polygonum scandens), Smartweed (P. spp.) Virginia Creeper (Parthenocissus quinquefolia), Greenbriar (Smilex spp.), Bedstraw (Gallium spp.) Jerusalem Artichoke (Helianthus tuberosus), Boneset (Eupatorium spp.) and Silver Maple (Acer saccharinum). Figure 7 shows a field dominated by goldenrod in an open field at Sand Ridge Nature Center and Figure 8 shows a wetland area dominated by Silver Maples.
Land and Air Pollution
For nearly a century the landscaping surrounding the communities of Calumet City and South Holland was heavily industrialized, with steel manufacturing and quarrying (limestone and sand) as the dominant industries. Much of the waste and other byproducts from these industries were deposited into local natural areas, particularity steel slag. Large quarries, most of which are now defunct, left large holes in the ground that eventually filled with water. Both slag dumping, land clearing, and hydrologic modifications have dramatically changed the ecology and soils of Sand Ridge Nature Center.
Further hydrological alterations prompted by increased land development of the surrounding neighborhood, particularity the conversion of agricultural land into "hardscapes" such as parking lots and commercial developments, have both increased the rate of urban stormwater runoff and have redirected the flow of surface water into Sand Ridge Nature Center. There has been no formal assessment on the impacts that stormwater runoff has had on natural areas within Sand Ridge Nature Center, but the recent formation of swampland habitat, which historically has only been present in southern Illinois, could be a symptom of a dramatic change in hydrology (figure 8).
Currently Cook County nor any other local government agency formally regulates urban stormwater, although an increasing number of communities are offering free rain barrels to home and business owners via the Metropolitan Water Reclamation District of Greater Chicago (2016).
Litter accumulation is a consistent problem along the outer boundaries of Sand Ridge Nature Center, particularly along roadways. Occasionally, nature center staff have observed oil slicks on the surface of some ponds and wet areas, possibly the result of improper motor oil disposal or illegal dumping of petroleum-based liquids.
Light pollution is a relatively new concept but has been shown to have negative impacts on the environment. Glow and glare from outdoor lights surrounding the Sand Ridge Nature Center property "leak" into the preserve resulting in artificial nighttime illumination. Although the impacts of light pollution on the flora and fauna of Sand Ridge Nature Center have not been formally assessed, recent research has indicated negative impacts on migratory bird populations, insect populations, and other wildlife populations such as bats. The International Dark Sky Association (IDA) releases articles and press releases highlighting recent research on the environmental impacts of light pollution (2016).
Several areas near Sand Ridge Nature Center have been designated as Superfund Sites, which are listed as National Priority Sites by the U.S. Environmental Protection Agency due to toxic levels of soil contaminants (see figure 9). Their impact on SRNC itself is likely minimal.
Socioeconomic Problems
The natural systems within Sand Ridge Nature Center are under stress from the various biological and physical problems mentioned above. More often than not regions with high environmental stressors also exhibit social and economic problems. The environmental justice movement, which was formalized into an area of active social research in the early 1990s, acknowledges the fact that "people who live, work and play in America's most polluted environments are commonly people of color and the poor" (NRDC, 2016). The latest census data for Calumet City, Illinois indicates the dominant presence of a low income working-class community. Less than 25% of the city's population processes a higher education degree, and nearly a quarter of the population under the age of 65 lacks health insurance (United States Census Bureau, 2016). The city's racial composition is primarily black (67.5%) followed by Hispanic (16.3%) as shown in Figure 10 (City-Data.com, 2016). As of 2015, the unemployment rate in Calumet City was 8.1% (City-Data.com, 2016).
Some of my own personal observations indicate to me that the community surrounding SRNC has a limited sense of regional identity among its residents (lack of sense of place based on location) as well as a lack of environmental awareness. As such SRNC seems to serve an underprivileged community. Again, beyond my own casual observations I am not aware of any formal publications or research on regional identity or environmental literacy among residents living near SRNC.
Given the correlation between race and living conditions with environmental degradation, it is possible that these two factors are connected and as such impact the ecological health of the of Sand Ridge Nature Center and the surrounding community? I do not claim to be an expert sociologist, and therefore my hypothesis would need to scrutinized by academic and government professionals who have expertise in socioeconomic analyses or community development. As we shall see, recent additions to SRNC's educational programming are a part of an ongoing attempt to reach out to an undeserved demographic.
A Sandy but Hopeful Future: Restoration Efforts
SRNC and other nearby Cook County forest preserve areas have had unprecedented environmental changes. In recent years the district has taken bold approaches to addressing its unique ecological problems as an urban forest preserve district. A full summary of the different restoration efforts and environmental education initiatives currently offered by the forest preserve district is going to be beyond the scope of this blog post, so I will focus exclusively on restoration and education activities at SRNC, which should offer a representative sample of he efforts of the district as a whole. A more exhaustive summary of the district-wide efforts can be found on the website for the Forest Preserve's Next Century Conservation Plan:
http://nextcenturyconservationplan.org/
Ecological restoration initiates have involved working with a variety of stakeholders, including internal resource management staff, private natural resource consultants, the non-profit agency Friends of the Forest Preserves, volunteers, and to a somewhat lesser extent local area school groups. One more combination of management techniques have been regularly implemented over the past 10 years at SRNC and include prescribed burns, brush-cutting of non-native woody vegetation, herbicide (foliar, basal, and cut-stump methods of application), and reseeding.
Prescribed Burns. Historically, the area that now encompasses SRNC had a mixture of open oak woodlands interspersed with wetland swales and marshes. Much of the "open feel" that this pre-Colonial landscape exhibits was due to periodic wildfires that were ignited by lighting strikes from the occasional "rain-free" zone of severe thunderstorms as well as indigenous peoples who would clear the land and light it on fire to attract game animals such as deer and bison (Schoon, 2003). With the suppression of wildfires by European Colinusts combined with the succession of fire-intolerant woody plant species such as Black Cherry (Prunus serotina) and European Buckthorn, much of this open landscape has given way to brushland. In recent years, fire has been reintroduced to SRNC in the form of carefully managed prescribed burns (figure 11). Combined with brush-cutting, a more open understory reminiscent of the pre-colonial condition of the region has formed in many of the woodland areas of SRNC (see figure 12).
Brushcutting. Sometimes utilized before a prescribed burn and sometimes used exclusively, this ecological management technique allows sunlight to penetrate the forest floor and stimulate growth of native wildflowers that were blocked by non-native brush (figure 12). In highly degraded areas with a depleted sandbank, reseeding with a wildflower seed mix or replanting of native woody trees and shrubs might follow.
Herbicide. Although it might seem ironic to some, the district uses herbicide extensively to manage growth of non-native invasive plants. Foliar application of herbaceous plants such as Lilly of the Valley of Purple Loostrife has been successful management techniques at SRNC, and cut-stump and basal application of herbicide on woody plants at SRNC has reduced the overall cover of invasive woody trees and shrubs in many sections of the preserve. For example, the oak woodland area on the right side of figure 12 was cleared of brush by contractors using primarily the cut-stump method of brush clearing and herbicide application. Staff, contractors, and volunteers are carefully trained in proper herbicide application techniques as well as to the appropriate conditions in which to safely apply herbicide.
Reseeding. Luckily, many sections of SRNC have not needed reseeding to the presence of a dormant seedbank whose growth becomes stimulated by sunlight not previously available due blockage by dense brush. Surprisingly the wetland area along the boardwalk in figure 13 regrew with native wetland plants shortly after construction activities disturbed the soil due after construction of the boardwalk itself. Some areas with depleted seedbanks, however, have shown minimal recovery of native vegetation and might need to be cleared again and reseeded.
Native Landscaping
Although the bulk of forest preserves land is managed in a natural state, some areas are maintained with native landscaping, often for the purposes of stormwater mitigation from parking lots and other manmade structures. The parking lot median at SRNC has redesigned into a depression seeded with native plants that allows for stormwater absorption and filtration as well as an auxiliary source of wildlife habitat (figure 14).
Rediscovering A Lost Beach: Education and Community-Based Conservation Efforts
As discussed above, the economic and social conditions of the communities surrounding SRNC are in a serious state of decline. Although SRNC and the Forest Preserves as organizations are not intended to addresssocial welfare programs, educational staff and facilities at SRNC could serve as a critical hub for community-based conservation initiatives.
It should be noted that engaging local stakeholders to support environmental restoration initiatives is critical for the ongoing support, funding, and success of long-term ecological landscape management. This should always be the overarching priority for SRNC. However, it is also important to note that successful community-centered conservation must address the needs of the people who live in the community in away that is mutually beneficial. SRNC staff have already begun projects and programs to engage the local community that addresses the ecological management needs of the preserve while also staying relevant to the interests of local community members.
Mighty Acorns. The Forest Preserve District has partnered with the Field Museum to host school groups from local area public schools for a field trip series where students in grades 3-5 visit SRNC to engage in experiential learning through ecologic lessons, exploration hikes, and a stewardship activity with a staff member. Each class comes out to the nature center once per season for three years, which for many undeserved public school students allows for a once-in-a-lifetime opportunity to connect with the resources of the forest preserves in an academic setting. In turn the forest preserves broadens its constituents by exposing young people to the presence of and the resources of the forest preserves, all the while helping to contribute to ecological restoration through seed collecting or invasive species removal. Both the Field Museum and the Forest Preserves provide funding assistance to schools that would not otherwise have a means of transportation for the students.
Calumet Is My Backyard (CIMBY). Another experiential learning program coordinated in part by the Field Museum, CIMBY is geared towards high-school aged students in the southeast portion of Cook County in areas near the Calumet River. Much like Mighty Acorns, students steward a specific place in the forest preserves with a greater focus on team building as well as building a sense of regional identify through exposure to local natural areas.
Free Ecology-themed School Field Trips. Although SRNC does not have the staffing nor facilitates that are comparable to high-profile museums and gardens, teachers from local schools (public and private) can arrange field trips for free guided by a naturalist. The importance of getting young constituents exposed to the resources of the forest preserve is emphasized.
Underground Railroad (UGRR) Programs
SRNC has recently made direct attempts to attract local visitors by catering to their interests. The development of their "Juneteenth Celebration", an annual festival commemorating the final enforcement of the Emancipation Proclamation which made slavery in the United States a federal prohibition, is held each year in mid-June at SRNC. The festival features naturalist-led imaginary history hikes through the Illinois portion of the UGGR, as well as period specific crafts and activities for families. During Black History Month (February), SRNC does a smaller-scale event commemorating the UGGR movement with a mid-Winter UGRR history hike, as well as during their Settler's Day and Archaeology Day festivals. Admission and parking to these events is free, making it accessible to lower income residents. Although SRNC does not contain any known UGRR sites, the Greater Chicago Area was considered a "hub" for the UGRR movement.
Educational Outreach
SRNC and other district nature centers offer free "Educational Adventures" programs to local schools. Naturalist staff will make arrangement with schools to come to their classroom and teach students about the plants and animals that make Cook County their home. This program is particularly helpful in reaching out to schools that might not otherwise have the financial resource to arrange a field trip to SRNC, and it helps to meet some of their required curriculum standards.
Promotional Outreach
SRNC staff will occasionally set up promotional booths at local community events such as farmer's markets or school career fairs to promote the nature center and its amenities (figure 15). Regular deliveries of program schedules and brochures are delivered to select venues within 5 miles of SRNC (in addition to locations coordinated by the district's general headquarters). SRNC also maintains an active social media page via Facebook:
https://www.facebook.com/Sand-Ridge-Nature-Center-485394718215678/
Conclusion
Sand Ridge Nature Center is an urban forest preserve that has felt the impacts of human activities both within its designated boundaries as well as in the surrounding landscape. Socioeconomic problems complement environmental stress faced by degraded natural areas such as SRNC. Nevertheless, SRNC still preserves small remnant pockets of high quality wetland and woodland areas (see figures 16 and 17). Continuing restoration efforts within the boundaries of the forest preserve as well as addressing urban landscape problems in the surrounding region should make it possible for natural areas within SRNC to be partially restored to its pre-Colonial condition. An enhanced focused on community-based conservation and education efforts has the potential to maximize SRNC as an educational and social service for community members residing in a region whose economic and social conditions are in need of improvement, especially when the programming is tailored to the respective demographic.
References
City-Data.com. (n.d.). Calumet City, Illinois. Retrieved May 27, 2016, from http://www.city-data.com/city/Calumet-City-Illinois.html
Ebird (2016). http://ebird.org/ebird/GuideMe?step=saveChoices&getLocations=hotspots&parentState=US-IL&bMonth=03&bYear=2016&eMonth=12&eYear=2016&reportType=location&hotspots=L152713&continue.x=85&continue.y=15
Forest Preserves of Cook County (2016). A History of the Sand Ridge Nature Center. Retrieved May 19, 2016 from http://fpdcc.com/nature-centers/sand-ridge-nature-center/a-history-of-the-sand-ridge-nature-center/
Holtz, M. (2012, October 4). Larger animals hearing call of the wild in Illinois. Chicago Tribune. Retrieved May 15, 2016, from http://articles.chicagotribune.com/2012-10-04/news/ct-met-coyote-studies-20121004_1_gray-wolves-gray-wolf-wolves-travel
International Dark Sky Association (2016). http://darksky.org/
MacAurthur, R. H., & Wilson, E. O. (1967). The Theory of Island Biogeophraphy [Abstract]. Monographs in Population Biology, 159(3810), 71-72.
Metropolitan Water Reclamation District of Greater Chicago. (n.d.). Rain Barrels. Retrieved May 26, 2016, from https://www.mwrd.org/irj/portal/anonymous/rainbarrel
NRDC. (2016, March 17). The Environmental Justice Movement. Retrieved May 27, 2016, from https://www.nrdc.org/stories/environmental-justice-movement
Schoon, K. J. (2003). Calumet Beginnings: Ancient Shorelines and Settlements at the South End of Lake Michigan. Bloomington, IN: Indiana University Press.
United States Census Bureau. (n.d.). Quickfacts: Calumet City, Illinois. Retrieved May 27, 2016, from http://www.census.gov/quickfacts/table/RHI805210/1710487
USFWS. (2015, April 14). Karner Blue Butterfly (Lycaeides melissa samuelis). Retrieved May 15, 2016, from https://www.fws.gov/midwest/endangered/insects/kbb/index.html
Since September of 2014, I have been serving the Forest Preserves of Cook County as a naturalist at a Chicago-area suburban nature education center situated in a 300 acre urban nature preserve. Sand Ridge Nature Center (SRNC), which geographically straddles the border of South Holland and Calumet City in Illinois, is named for the ancient high Toleston Beach Ridge that formed as the water levels of Lake Michigan began receding after the end of the last major ice age (figure 1) (Forest Preserves of Cook County, 2016). The former 6,000 year-old beach ridge is still partially intact in several forest preserves, with one the longest remaining stretches on the northern end of the nature center property along Michigan City Road (figure 2). The present extent of Sand Ridge Nature Center includes all of the land north of U.S. Highway 6 to Michigan City Road, then from Paxton Avenue east to Illinois Highway 83 (Torrence Avenue) along the municipal boundaries of South Holland and Calumet City.
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| Figure 1: Retreat of L. Michigan shoreline following the last ice age. Image Source: http://digthedunes.com/shorelines-shorelines-everywhere/ |
It should be noted that SRNC does not exist in a vacuum but is in fact part of a larger network of forest preserves and other natural areas that are geographically distributed across Cook County, Illinois. Nonetheless, I will place a spotlight almost exclusively on SRNC since it is one of the few managed natural areas in the region with developed spaces for education programs and exhibits that facilitate an experience for visitors and other members of the public.
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| Figure 2: Sand Ridge Nature Center is named for the ancient High Toleston Beach Ridge that still remains intact along the northern edge of the preserve (indicated by red line). |
Habitat Isolation
Famed ecologists Edward O. Wilson and Robert MacArthur (1967) conceptualized the local loss of species and ecosystem degradation through their island biogeography model which compared natural areas isolated by human activities (urban development, agriculture, etc.) as islands in a sea with respect to their ecosystem functions and species population dynamics. Wilson and MacArthur concluded that islands that were relatively large in size were often more stable in regards to species composition, and often served as source populations that could colonize other geographic areas (or other islands). Smaller islands that are close by to larger islands could presumably gain species populations via immigration from nearby source populations, while smaller islands that are far away from mainlands were much more vulnerable to species loss due to their distant proximity to a source population. Wilson and MacArthur argued that natural areas isolated by human activities function on an island biogeography dynamic, with smaller and fragmented natural landscapes undergoing species loss and degradation as humans modify the surrounding landscape. Sand Ridge Nature Center and nearby adjoining forest preserve tracts are, for the most part, surrounded on all four sides by urban and suburban development, including the presence of River Oaks Mall, a large and aging shopping center located just outside the boundaries of SRNC and the Green Lake forest preserve properties (see figure 3).
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| Figure 3: Sand Ridge Nature Center and nearby forest preserve land are flanked on all four sides by urban and suburban development, including River Oaks Mall just to the south of Sand Ridge Nature Center (see lower-middle portion of map). |
The isolated condition of SRNC might be the reason for the absence or lack of abundance of some flora and fauna species, as discussed below. It also also led to the "edge-effect" where there is less interior habitat and more transitional areas such as scrubland that favor generalist species of plants and animals such as green ash (Fraxinus pennsylvanica) or Eastern Cottontail rabbits (Sylvilagus floridanus).
Species population depletion
Bears, wolves, and other large tertiary predators were extirpated from northern Illinois by the end of 19th century (Schoon, 2003). Although there have been some anomalous sightings of large predators in recent years (Holtz, 2012), lack of suitable habitat has prevented recovery of most large predator populations. Therefore the scarcity of predatory wildlife has benefited some large herbivore populations such as white-tailed deer (Odocoileus virginianus) (see figure 4). White-tailed deer and other animals have also benefited from increased suitable habitat, particularly edge habitat, as mentioned above.
More recent species population depletion includes those of reptiles and amphibians. At present date, SRNConly has 7 of 13 known species of amphibians in Cook County and only 5 of 9 reptile species (Anton, 1999). Cook County overall has lost 13 additional species of reptiles and amphibians since 1940 (Anton, 1999). One plausible explanation for this sharp drop in reptile and amphibian diversity is the large-scale fragmentation of natural lands in the region, with enhanced urbanization taking place during the 1970s into the 1990s with the development of the River Oaks Mall shopping center at the Bishop-Ford Freeway (Interstate 94). Impacts to water quality from accelerated run-off may also be a confounding factor (discussed below).
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| Figure 4: A lack of predators alongside fragmented habitat has dramatically increased certain herbivore animal species such as white-tailed deer. Image credits: Jacob Huffman/Forest Preserves of Cook County |
Bird diversity has declined in recent years, although not as dramatically as other wildlife groups. The Passenger Pigeon (Ectopistes migratorius) became extinct by 1908 (Schoon, 2003) alongside the Ivory-Billed Woodpecker (Campephilis prinicpalis), which may have historically been present in the region. Bald Eagles and Osprey are uncommon sightings but their populations have rebounded in recent years across northern Illinois and are occasionally observed at SRNC. As of this writing, over 110 species of birds have been observed within the boundaries of Sand Ridge Nature Center (eBird, 2016).
Changes in insect and other invertebrate diversity has yet to be formally assessed. Sand Ridge Nature Center is just within the range of the federally endangered Karner Blue Butterfly (USFWS, 2015), although no recent sightings have been documented.
All species of Ash trees (Fraxinus spp.) are in a sharp decline due to the accidental introduction of the Emerald Ash Borer beetle (Agrilus planipennis) (figure 5).
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| Figure 5: Emerald Ash-Borer is an invasive insect that has been decimating ash tree populations at Sand Ridge Nature Center. |
Invasive Species
Habitat fragmentation and degradation leading to species population decline has been exacerbated by non-native, invasive species.
Since the beginning of the 19th century, about 150 introduced plant species have become invasive and form monocultures in otherwise diverse ecosystems (e.g. prairies), generally becoming well established in areas with high disturbance (NRCS Illinois, 2016). SRNC's most problematic invasive plants include European Buckthorn (Rhamnus cathartica), Glossy Buckthorn (Frangula alnus), Japanese Bush Honeysuckle (Lonicera spp.), Canada Thistle (Circium arvense), Garlic Mustard (Allaria Petiolata, see figure 6), Oriental Bittersweet (Celastrus orbiculatis), Lilly-of-the-valley (Convallaria majalis), Purple Loostrife (Lythrum salicaria), Common Reed (Phragmites australis), and Cattail (Typha spp.). Purple Loosestrife, Common Reed, and Cattail presently dominate at least 70% of Sand Ridge Nature Center's wetland areas. There may be other invasive plant species established at Sand Ridge Nature Center, but they have not been formally documented nor observed. Nature center staff have been keeping an informal rolling inventory of the emergence of invasive plant species on iNaturalist:
http://www.inaturalist.org/projects/invasive-plant-species-of-sand-ridge
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| Figure 6: Garlic mustard invades a woodland area at Sand Ridge Nature Center. |
SRNC also has some invasive, non-native animal species present. House Sparrows (Passer domesticus), originally native to Europe, compete with native bird species such as Eastern Bluebirds (Sialia sialis) for habitat and nesting sights, although bluebirds and other native birds do not appear entirely inhibited by the presence of house sparrows. European Starlings (Sturnis vulgaris), and House Finches (Haemorhous mexicanus) are present as well, but their impacts on Sand Ridge Nature Center's birds do not appear to be substantial. A long-term inventory of Sand Ridge Nature Center's birds (breeding and migratory) can viewed on eBird:
http://ebird.org/ebird/GuideMe?step=saveChoices&getLocations=hotspots&parentState=US-IL&bMonth=03&bYear=2016&eMonth=12&eYear=2016&reportType=location&hotspots=L152713&continue.x=85&continue.y=15
There might also be non-native invasive fungi and insects, but no formal inventory or observations have been made regarding the presence of invasive invertebrates or fungi with the exception of the invasive Emerald Ash Borer beetle mentioned earlier in this blog post. Cook County has done formal inventories of mosquito populations at Sand Ridge Nature Center, but at the time of this writing their data is not within accessible form.
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| Figure 7: Goldenrod. |
Land and Air Pollution
For nearly a century the landscaping surrounding the communities of Calumet City and South Holland was heavily industrialized, with steel manufacturing and quarrying (limestone and sand) as the dominant industries. Much of the waste and other byproducts from these industries were deposited into local natural areas, particularity steel slag. Large quarries, most of which are now defunct, left large holes in the ground that eventually filled with water. Both slag dumping, land clearing, and hydrologic modifications have dramatically changed the ecology and soils of Sand Ridge Nature Center.
Further hydrological alterations prompted by increased land development of the surrounding neighborhood, particularity the conversion of agricultural land into "hardscapes" such as parking lots and commercial developments, have both increased the rate of urban stormwater runoff and have redirected the flow of surface water into Sand Ridge Nature Center. There has been no formal assessment on the impacts that stormwater runoff has had on natural areas within Sand Ridge Nature Center, but the recent formation of swampland habitat, which historically has only been present in southern Illinois, could be a symptom of a dramatic change in hydrology (figure 8).
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| Figure 8: The presence of a swampland dominated by Silver Maple might be an indicator of severe hydrological alterations of the landscape surrounding Sand Ridge Nature Center. |
Currently Cook County nor any other local government agency formally regulates urban stormwater, although an increasing number of communities are offering free rain barrels to home and business owners via the Metropolitan Water Reclamation District of Greater Chicago (2016).
Litter accumulation is a consistent problem along the outer boundaries of Sand Ridge Nature Center, particularly along roadways. Occasionally, nature center staff have observed oil slicks on the surface of some ponds and wet areas, possibly the result of improper motor oil disposal or illegal dumping of petroleum-based liquids.
Light pollution is a relatively new concept but has been shown to have negative impacts on the environment. Glow and glare from outdoor lights surrounding the Sand Ridge Nature Center property "leak" into the preserve resulting in artificial nighttime illumination. Although the impacts of light pollution on the flora and fauna of Sand Ridge Nature Center have not been formally assessed, recent research has indicated negative impacts on migratory bird populations, insect populations, and other wildlife populations such as bats. The International Dark Sky Association (IDA) releases articles and press releases highlighting recent research on the environmental impacts of light pollution (2016).
Several areas near Sand Ridge Nature Center have been designated as Superfund Sites, which are listed as National Priority Sites by the U.S. Environmental Protection Agency due to toxic levels of soil contaminants (see figure 9). Their impact on SRNC itself is likely minimal.
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| Figure 9: National Priority sites within 5 miles of Sand Ridge Nature Center. |
Socioeconomic Problems
The natural systems within Sand Ridge Nature Center are under stress from the various biological and physical problems mentioned above. More often than not regions with high environmental stressors also exhibit social and economic problems. The environmental justice movement, which was formalized into an area of active social research in the early 1990s, acknowledges the fact that "people who live, work and play in America's most polluted environments are commonly people of color and the poor" (NRDC, 2016). The latest census data for Calumet City, Illinois indicates the dominant presence of a low income working-class community. Less than 25% of the city's population processes a higher education degree, and nearly a quarter of the population under the age of 65 lacks health insurance (United States Census Bureau, 2016). The city's racial composition is primarily black (67.5%) followed by Hispanic (16.3%) as shown in Figure 10 (City-Data.com, 2016). As of 2015, the unemployment rate in Calumet City was 8.1% (City-Data.com, 2016).
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| Figure 10: Races in Calumet City, IL. Graph Source: http://www.city-data.com/city/Calumet-City-Illinois.html |
Some of my own personal observations indicate to me that the community surrounding SRNC has a limited sense of regional identity among its residents (lack of sense of place based on location) as well as a lack of environmental awareness. As such SRNC seems to serve an underprivileged community. Again, beyond my own casual observations I am not aware of any formal publications or research on regional identity or environmental literacy among residents living near SRNC.
Given the correlation between race and living conditions with environmental degradation, it is possible that these two factors are connected and as such impact the ecological health of the of Sand Ridge Nature Center and the surrounding community? I do not claim to be an expert sociologist, and therefore my hypothesis would need to scrutinized by academic and government professionals who have expertise in socioeconomic analyses or community development. As we shall see, recent additions to SRNC's educational programming are a part of an ongoing attempt to reach out to an undeserved demographic.
A Sandy but Hopeful Future: Restoration Efforts
SRNC and other nearby Cook County forest preserve areas have had unprecedented environmental changes. In recent years the district has taken bold approaches to addressing its unique ecological problems as an urban forest preserve district. A full summary of the different restoration efforts and environmental education initiatives currently offered by the forest preserve district is going to be beyond the scope of this blog post, so I will focus exclusively on restoration and education activities at SRNC, which should offer a representative sample of he efforts of the district as a whole. A more exhaustive summary of the district-wide efforts can be found on the website for the Forest Preserve's Next Century Conservation Plan:
http://nextcenturyconservationplan.org/
Ecological restoration initiates have involved working with a variety of stakeholders, including internal resource management staff, private natural resource consultants, the non-profit agency Friends of the Forest Preserves, volunteers, and to a somewhat lesser extent local area school groups. One more combination of management techniques have been regularly implemented over the past 10 years at SRNC and include prescribed burns, brush-cutting of non-native woody vegetation, herbicide (foliar, basal, and cut-stump methods of application), and reseeding.
Prescribed Burns. Historically, the area that now encompasses SRNC had a mixture of open oak woodlands interspersed with wetland swales and marshes. Much of the "open feel" that this pre-Colonial landscape exhibits was due to periodic wildfires that were ignited by lighting strikes from the occasional "rain-free" zone of severe thunderstorms as well as indigenous peoples who would clear the land and light it on fire to attract game animals such as deer and bison (Schoon, 2003). With the suppression of wildfires by European Colinusts combined with the succession of fire-intolerant woody plant species such as Black Cherry (Prunus serotina) and European Buckthorn, much of this open landscape has given way to brushland. In recent years, fire has been reintroduced to SRNC in the form of carefully managed prescribed burns (figure 11). Combined with brush-cutting, a more open understory reminiscent of the pre-colonial condition of the region has formed in many of the woodland areas of SRNC (see figure 12).
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| Figure 11: Prescribed burn of a small remnant sand prairie at SRNC. Photo credits: Jacob Huffman/Forest Preserves of Cook County. |
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| Figure 12: Brush clearing as well as prescribed burns have allowed brushland areas of SRNC to give way to a more traditional open oak woodland habitat structure. |
Herbicide. Although it might seem ironic to some, the district uses herbicide extensively to manage growth of non-native invasive plants. Foliar application of herbaceous plants such as Lilly of the Valley of Purple Loostrife has been successful management techniques at SRNC, and cut-stump and basal application of herbicide on woody plants at SRNC has reduced the overall cover of invasive woody trees and shrubs in many sections of the preserve. For example, the oak woodland area on the right side of figure 12 was cleared of brush by contractors using primarily the cut-stump method of brush clearing and herbicide application. Staff, contractors, and volunteers are carefully trained in proper herbicide application techniques as well as to the appropriate conditions in which to safely apply herbicide.
Reseeding. Luckily, many sections of SRNC have not needed reseeding to the presence of a dormant seedbank whose growth becomes stimulated by sunlight not previously available due blockage by dense brush. Surprisingly the wetland area along the boardwalk in figure 13 regrew with native wetland plants shortly after construction activities disturbed the soil due after construction of the boardwalk itself. Some areas with depleted seedbanks, however, have shown minimal recovery of native vegetation and might need to be cleared again and reseeded.
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| Figure 13: Native wetland vegetation along the Lost Beach Trail boardwalk at SRNC. |
Native Landscaping
Although the bulk of forest preserves land is managed in a natural state, some areas are maintained with native landscaping, often for the purposes of stormwater mitigation from parking lots and other manmade structures. The parking lot median at SRNC has redesigned into a depression seeded with native plants that allows for stormwater absorption and filtration as well as an auxiliary source of wildlife habitat (figure 14).
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| Figure 14: Bioswale with native plants within the median of the SRNC Parking Lot. |
Rediscovering A Lost Beach: Education and Community-Based Conservation Efforts
As discussed above, the economic and social conditions of the communities surrounding SRNC are in a serious state of decline. Although SRNC and the Forest Preserves as organizations are not intended to addresssocial welfare programs, educational staff and facilities at SRNC could serve as a critical hub for community-based conservation initiatives.
It should be noted that engaging local stakeholders to support environmental restoration initiatives is critical for the ongoing support, funding, and success of long-term ecological landscape management. This should always be the overarching priority for SRNC. However, it is also important to note that successful community-centered conservation must address the needs of the people who live in the community in away that is mutually beneficial. SRNC staff have already begun projects and programs to engage the local community that addresses the ecological management needs of the preserve while also staying relevant to the interests of local community members.
Mighty Acorns. The Forest Preserve District has partnered with the Field Museum to host school groups from local area public schools for a field trip series where students in grades 3-5 visit SRNC to engage in experiential learning through ecologic lessons, exploration hikes, and a stewardship activity with a staff member. Each class comes out to the nature center once per season for three years, which for many undeserved public school students allows for a once-in-a-lifetime opportunity to connect with the resources of the forest preserves in an academic setting. In turn the forest preserves broadens its constituents by exposing young people to the presence of and the resources of the forest preserves, all the while helping to contribute to ecological restoration through seed collecting or invasive species removal. Both the Field Museum and the Forest Preserves provide funding assistance to schools that would not otherwise have a means of transportation for the students.
Calumet Is My Backyard (CIMBY). Another experiential learning program coordinated in part by the Field Museum, CIMBY is geared towards high-school aged students in the southeast portion of Cook County in areas near the Calumet River. Much like Mighty Acorns, students steward a specific place in the forest preserves with a greater focus on team building as well as building a sense of regional identify through exposure to local natural areas.
Free Ecology-themed School Field Trips. Although SRNC does not have the staffing nor facilitates that are comparable to high-profile museums and gardens, teachers from local schools (public and private) can arrange field trips for free guided by a naturalist. The importance of getting young constituents exposed to the resources of the forest preserve is emphasized.
Underground Railroad (UGRR) Programs
SRNC has recently made direct attempts to attract local visitors by catering to their interests. The development of their "Juneteenth Celebration", an annual festival commemorating the final enforcement of the Emancipation Proclamation which made slavery in the United States a federal prohibition, is held each year in mid-June at SRNC. The festival features naturalist-led imaginary history hikes through the Illinois portion of the UGGR, as well as period specific crafts and activities for families. During Black History Month (February), SRNC does a smaller-scale event commemorating the UGGR movement with a mid-Winter UGRR history hike, as well as during their Settler's Day and Archaeology Day festivals. Admission and parking to these events is free, making it accessible to lower income residents. Although SRNC does not contain any known UGRR sites, the Greater Chicago Area was considered a "hub" for the UGRR movement.
Educational Outreach
SRNC and other district nature centers offer free "Educational Adventures" programs to local schools. Naturalist staff will make arrangement with schools to come to their classroom and teach students about the plants and animals that make Cook County their home. This program is particularly helpful in reaching out to schools that might not otherwise have the financial resource to arrange a field trip to SRNC, and it helps to meet some of their required curriculum standards.
Promotional Outreach
SRNC staff will occasionally set up promotional booths at local community events such as farmer's markets or school career fairs to promote the nature center and its amenities (figure 15). Regular deliveries of program schedules and brochures are delivered to select venues within 5 miles of SRNC (in addition to locations coordinated by the district's general headquarters). SRNC also maintains an active social media page via Facebook:
https://www.facebook.com/Sand-Ridge-Nature-Center-485394718215678/
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| Figure 15: Myself |
Conclusion
Sand Ridge Nature Center is an urban forest preserve that has felt the impacts of human activities both within its designated boundaries as well as in the surrounding landscape. Socioeconomic problems complement environmental stress faced by degraded natural areas such as SRNC. Nevertheless, SRNC still preserves small remnant pockets of high quality wetland and woodland areas (see figures 16 and 17). Continuing restoration efforts within the boundaries of the forest preserve as well as addressing urban landscape problems in the surrounding region should make it possible for natural areas within SRNC to be partially restored to its pre-Colonial condition. An enhanced focused on community-based conservation and education efforts has the potential to maximize SRNC as an educational and social service for community members residing in a region whose economic and social conditions are in need of improvement, especially when the programming is tailored to the respective demographic.
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| Figure 16 : Woodland area at Sand Ridge Nature Center with native wildflowers in the understory. |
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| Figure 17 : "Dogwood Marsh" with native wetland plants at Sand Ridge Nature Center. |
References
City-Data.com. (n.d.). Calumet City, Illinois. Retrieved May 27, 2016, from http://www.city-data.com/city/Calumet-City-Illinois.html
Ebird (2016). http://ebird.org/ebird/GuideMe?step=saveChoices&getLocations=hotspots&parentState=US-IL&bMonth=03&bYear=2016&eMonth=12&eYear=2016&reportType=location&hotspots=L152713&continue.x=85&continue.y=15
Forest Preserves of Cook County (2016). A History of the Sand Ridge Nature Center. Retrieved May 19, 2016 from http://fpdcc.com/nature-centers/sand-ridge-nature-center/a-history-of-the-sand-ridge-nature-center/
Holtz, M. (2012, October 4). Larger animals hearing call of the wild in Illinois. Chicago Tribune. Retrieved May 15, 2016, from http://articles.chicagotribune.com/2012-10-04/news/ct-met-coyote-studies-20121004_1_gray-wolves-gray-wolf-wolves-travel
International Dark Sky Association (2016). http://darksky.org/
Metropolitan Water Reclamation District of Greater Chicago. (n.d.). Rain Barrels. Retrieved May 26, 2016, from https://www.mwrd.org/irj/portal/anonymous/rainbarrel
Schoon, K. J. (2003). Calumet Beginnings: Ancient Shorelines and Settlements at the South End of Lake Michigan. Bloomington, IN: Indiana University Press.
United States Census Bureau. (n.d.). Quickfacts: Calumet City, Illinois. Retrieved May 27, 2016, from http://www.census.gov/quickfacts/table/RHI805210/1710487
USFWS. (2015, April 14). Karner Blue Butterfly (Lycaeides melissa samuelis). Retrieved May 15, 2016, from https://www.fws.gov/midwest/endangered/insects/kbb/index.html
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