ALLERTON PARK & RETREAT CENTER: NATURAL AREAS MANAGEMENT PLAN Prepared: December, 1992 Robert E. Szafoni1, Francis M. Harty2 Revised: January, 2012 John D. Griesbaum3 1Illinois Department of Natural Resources Division of Natural Heritage 2The Nature Conservancy 3University of Illinois - Allerton Park & Retreat Center CONTENTS CHAPTER 1 ...................................................... 1 INTRODUCTION ................................................. 1 PRESETTLEMENT CONDITIONS OF ALLERTON PARK .................... 1 CURRENT STATUS OF SIGNIFICANT RESOURCES ....................... 2 ECOLOGICAL THREATS TO NATURAL AREAS .......................... 5 1. Exotic Species ................................................ 5 2. Altered Successional Patterns ...................................... 5 3. Other Disturbances ............................................. 6 AMOUNT OF CURRENT/POTENTIAL VISITOR USAGE ..................... 6 OVERALL MANAGEMENT GOALS ................................... 7 OVERALL MANAGEMENT RECOMMENDATIONS ........................ 7 A. Prescribed Burning ............................................. 7 B. Exotic Species Control .......................................... 8 C. Control of Undesirable Woody Vegetation ............................. 9 D. Enhance Diversity of Prairie Reconstruction ............................ 9 E. Survey & Monitoring of Species of Management Concern ................... 9 F. White-Tail Deer Control ........................................ 10 VOLUNTEER OPPORTUNITIES ..................................... 10 RESEARCH OPPORTUNITIES ...................................... 11 LANDSCAPE RESTORATION OPPORTUNITY ........................... 12 DEVELOP PARTNERSHIPS ........................................ 13 BIOFUELS .................................................... 13 CHAPTER 2 ..................................................... 14 MANAGEMENT SCHEDULES ...................................... 14 SUN SINGER ................................................. 15 CENTAUR ................................................... 20 FU DOG ..................................................... 24 BLACK ..................................................... 28 GREEN ..................................................... 33 BLUE ...................................................... 38 RED ....................................................... 43 ORANGE .................................................... 48 BUDGET ....................................................... 53 LITERATURE CITED .............................................. 54 FIGURES ....................................................... 56 APPENDIX 1 ..................................................... 58 APPENDIX 2 ..................................................... 59 CHAPTER 1 INTRODUCTION Allerton Park has long been recognized as one of Illinois' most significant natural areas. It is located in the Grand Prairie Natural Division (Schwegman, et al. 1973) and contains outstanding examples of old-growth floodplain and upland forest. It supports populations of the state endangered eastern massasauga (Sistrurus catenatus), state threatened Kirtland's watersnake (Clonophis kirtlandii), black-billed cuckoo (Coccyzus erythropthalmus) and Mudpuppy (Necturus maculosus). Allerton Park is one of only three areas in central Illinois with over 500 acres of contiguous forest. Large forested tracts are important breeding areas for many neotropical migrant birds whose populations have declined dramatically as forest fragmentation has created smaller and more isolated woodlots. The high diversity of natural communities and native species, especially forest trees and wildflowers, and the park's location along an unmodified reach of the Sangamon River also contribute to the high natural quality of the site. A portion of the site has been recognized as a National Natural Landmark by the U. S. Park Service. PRESETTLEMENT CONDITIONS OF ALLERTON PARK The land which makes up the present day Allerton Park was first surveyed by the federal government's General Land Office during February - July 1822. The surveyors moved through areas in a systematic fashion establishing the township, range, and sections we know today. In establishing these lines in the field, surveyors recorded witness and bearing trees (species, diameter, & distance from section post), general descriptions of the surrounding land, locations of changes in land features (forests, prairies, ponds, and/or rivers), and the width and flow of all rivers, creeks, and brooks. In general, the surveyors were good naturalists who knew their plants and their records are considered to be very reliable (Bourdo, 1956; Hutchison, 1988). The systematic fashion in which the survey was performed and the quantitative nature of witness tree data permits an interpretation of probable distribution of natural communities at the time the surveys were done (Anderson & Anderson, 1975). As these surveys were performed before widespread European settlement, the data provides an insight to the vegetation present in an area before disturbance by white settlers - a glimpse of the landscape in its original natural condition. 1 These records indicate that Allerton Park was almost entirely wooded at the time of settlement (Fig. 1). Prairie was present at four locations in the park; in the far southeast corner near the current prairie planting, in the floodplain at the far northeast end of the park (part of a larger bottomland prairie which extended from this point upstream about two miles), north of the road between the formal gardens and 4-H camp and between the picnic area and Fu Dog garden. Upland forests occurred on the ridges above the river valley. Tree species recorded here were white oak, black oak, and hickory. Savanna, or a savanna-like community, existed between the prairie at the southeast end of the park and the upland forest. Though pin oak was recorded by the surveyors in these areas, it is possible that what they saw was shingle oak; in the absence of leaves both species display an unusual, decurrent branching pattern and pin oak would be more commonly found in low, wet areas. Generally, the understory was fairly open and contained hazel and briars (Rubus sp.). At the northwest corner of the prairie planting, the hazel and briars were "thick as damnation". Bottomland forests were present throughout the park's floodplain. Tree species noted include bur oak, sycamore, elm, and honey locust. With the exception of the small area at the northeast corner of the park, no bottomland prairie was present in the park. The interaction of fire and topography had a profound effect on the presettlement vegetation of Allerton Park. Frequent fires were an important component in the prairies which occurred on the uplands away from the river valley. These fires crept into the forests and were important in maintaining oak-hickory forest on the dissected uplands near the valley and the savannas at the interface between the prairie and forest. The ravines and bottomlands, more protected from fire, supported fire sensitive species such as elm, honey locust and basswood, as well as oaks and hickories. CURRENT STATUS OF SIGNIFICANT RESOURCES The Illinois Natural Areas Inventory (INAI) surveyed Allerton Park in 1976 and 2008 documenting 470 acres of very high (grade A) and high (grade B) quality forest on the site (Fig. 2). This is the largest area of high quality forest in the Grand Prairie Natural Division (White, 1978). Allerton Park holds INAI category designations of I (high quality natural communities) and II (specific suitable habitat for endangered or threatened species; Appendix 1). Natural communities include: • Dry-mesic upland forest 2 o Grade A = 91 ac. old growth & old second growth o Grade B = 45 ac. old growth & old second growth, grazed o Grade C = 191 ac. logged, grazed • Mesic upland forest o Grade A = 24 ac. old growth & old second growth o Grade B = 18 ac. old growth & old second growth, grazed o Grade C = 55 ac. logged, grazed • Wet floodplain forest o Grade B = 292 ac. relatively undisturbed o Grade C = 176 ac. young to mature forest The upper Sangamon River corridor, from its origin (Mclean County NW of Saybrook) to the Piatt/Macon County line, varying from a large creek (width 4-6 feet) to a small river (width 35-50 feet) flows through Allerton Park. The Sangamon River depths range to four feet. Stream habitats include sand and mud bars, rapids, riffles, and fairly deep pools. The Sangamon River holds INAI category designations of II (specific suitable habitat for endangered or threatened species), III (Dedicated Nature Preserves, Registered Land and Water Reserves, and Enrolled Natural Heritage Landmarks) and VI (Unusual Concentrations of Flora and Fauna). (Appendix 2) Allerton Park is one of 13 protected natural areas along the Sangamon River corridor that, taken together, preserve more than 11.5 miles of the Sangamon River and over 4,410 acres of forest and other natural land along the Sangamon River corridor in Piatt and Champaign counties. The Upper Sangamon River Land and Water Reserve (USRLWR), is immediately adjacent to the north east of Allerton. This reserve contains upland and bottomland forest, grassland and old field habitats. Allerton Park and USRLWR together protect ~6 miles of Sangamon River and ~2000 acres of land. Furthermore, USRLWR and Allerton Park together comprise one of the largest remaining forests in central Illinois. Four species of conservation concern occur within Allerton Park. Two reptiles: