Shumard Oak Quercus shummardii

Transcription

1 COSEWIC Assessment and Update Status Report on the Shumard Oak Quercus shummardii in Canada SPECIAL CONCERN 1999 COSEWIC COMMITTEE ON THE STATUS OF ENDANGERED WILDLIFE IN CANADA COSEPAC COMITÉ SUR LA SITUATION DES ESPÈCES EN PÉRIL AU CANADA

2 COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows: Please note: Persons wishing to cite data in the report should refer to the report (and cite the author(s)); persons wishing to cite the COSEWIC status will refer to the assessment (and cite COSEWIC). A production note will be provided if additional information on the status report history is required. COSEWIC COSEWIC assessment and update status report on the shumard oak Quercus shumardii in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 11 pp. ( White, D.J Update COSEWIC status report on the shumard oak Quercus shumardii in Canada in COSEWIC assessment and update status report on the shumard oak Quercus shumardii in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa pp. Previous report: Waldron, G COSEWIC status report on the shumard oak Quercus shumardii in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 25 pp. Production note: General information from the original status report by Gerald Waldron has been included in this update report. For additional copies contact: COSEWIC Secretariat c/o Canadian Wildlife Service Environment Canada Ottawa, ON K1A 0H3 Tel.: (819) / (819) Fax: (819) COSEWIC/COSEPAC@ec.gc.ca Ếgalement disponible en français sous le titre Ếvaluation et Rapport de situation du COSEPAC sur la situation du chêne de Shumard (Quercus shummardii) au Canada Mise à jour. Cover illustration: Shumard Oak Acorn and leafy branch of Shumard Oak (Susan Laurie-Bourque, courtesy of Canadian Museum of Nature). Minister of Public Works and Government Services Canada 2003 Catalogue No. CW69-14/ E-PDF ISBN HTML: CW69-14/ E-HTML Recycled paper

3 COSEWIC Assessment Summary Assessment summary April 1999 Common name Shumard Oak Scientific name Quercus shumardii Status Special Concern Reason for designation Many small, remnant populations and scattered trees within two restricted geographical areas. The tree has a limited capability for regeneration and is at risk from hybridization with other oaks. Occurrence Ontario Status history Designated Special Concern in April Status re-examined and confirmed in April Last assessment based on an update status report. iii

4 COSEWIC Executive Summary Shumard Oak Quercus shumardii Species Information Shumard Oak is a large tree with massive limbs and an open, wide-spreading canopy. Older specimens have a heavily buttressed trunk that is covered with dark grey furrowed bark. The bark of younger limbs has smooth light grey bark. Branchlets are reddish or greyish brown with terminal buds that are oval, pointed and grey. The leaves are 5-7 lobed, with the lobes cut more than half way to the midrib. The upper leaf surface is lustrous and the lower has conspicuous tufts of hair in the axils of the veins. Leaves turn a deep wine-red in the fall. Acorns are about 2.5 cm long and enclosed by a shallow flat-topped grey cup. Distribution The species is found throughout eastern North America from Indiana and North Carolina south to Texas and northern Florida. Isolated outliers occur in southern Pennsylvania, Kentucky, and Virginia but it is largely absent from the Appalachians. Its Canadian range is restricted to southwestern Ontario. Habitat Shumard Oak prefers rich, moist, poorly-drained clay and clay loam soil in deciduous woodlands. Biology Little specific information has been compiled on the biology of this species. Like other oaks, this species requires full sunlight for seedling establishment. These conditions are met, in particular, at sites where the trees occur along fencerows and along roadsides. Shumard Oak also regenerates through its ability to sprout from stumps after brushing activities along fencerows. iv

5 Population sizes and trends Thorough inventories have not been undertaken to determine the full extent and distribution of Shumard Oak within southwestern Ontario, however, several people have searched the five known counties/regional municipalities (see Figure 3) at various times and recorded tree size and numbers of trees (Waldron et al.,1987; Oldham, 1998). Most sites consist of single, relic trees along fencerows or in fields. Regeneration is reported at some sites where the oak occurs in woods or occasionally in open fields. Fencerow trees are sometimes cut down during fenceline brushing operations, but the oak is able to re-sprout from the base and thus at least persist at such locations (Waldron et al., 1987). Fewer than 40 locations are presently known for this tree with the total number likely being <<1000 and possibly only as many as 250. Limiting factors and threats Many of the sites of Shumard Oak occur in fencerows, fields, or along roads. Such isolated trees are at risk from fencerow brushing and field clearing. Large forest-grown trees are at risk from logging. Confusion with similar species such as red oak increases this species vulnerability from inadvertent loss from the above-named activities. Special significance of the species It has the potential for being used as an ornamental and for planting in parks. Existing protection or other status designations No specific actions have been taken to protect this species. Three of the sites for this species occur in protected areas. v

6 COSEWIC MANDATE The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) determines the national status of wild species, subspecies, varieties, and nationally significant populations that are considered to be at risk in Canada. Designations are made on all native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fish, lepidopterans, molluscs, vascular plants, lichens, and mosses. COSEWIC MEMBERSHIP COSEWIC comprises representatives from each provincial and territorial government wildlife agency, four federal agencies (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biosystematic Partnership), three nonjurisdictional members and the co-chairs of the species specialist groups. The committee meets to consider status reports on candidate species. DEFINITIONS Species Extinct (X) Extirpated (XT) Endangered (E) Threatened (T) Special Concern (SC)* Not at Risk (NAR)** Data Deficient (DD)*** Any indigenous species, subspecies, variety, or geographically defined population of wild fauna and flora. A species that no longer exists. A species no longer existing in the wild in Canada, but occurring elsewhere. A species facing imminent extirpation or extinction. A species likely to become endangered if limiting factors are not reversed. A species of special concern because of characteristics that make it particularly sensitive to human activities or natural events. A species that has been evaluated and found to be not at risk. A species for which there is insufficient scientific information to support status designation. * Formerly described as Vulnerable from 1990 to 1999, or Rare prior to ** Formerly described as Not In Any Category, or No Designation Required. *** Formerly described as Indeterminate from 1994 to 1999 or ISIBD (insufficient scientific information on which to base a designation) prior to The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. Environment Canada Canadian Wildlife Service Environnement Canada Service canadien de la faune Canada The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat. vi

7 Update COSEWIC Status Report on the Shumard Oak Quercus shummardii in Canada David J. White 1999

8 TABLE OF CONTENTS SPECIES INFORMATION... 3 Name and classification... 3 Description... 3 DISTRIBUTION... 4 Global range... 4 Canadian range... 4 HABITAT...5 Habitat requirements... 5 Protection/ownership... 5 BIOLOGY... 5 POPULATION SIZES AND TRENDS... 6 Essex County... 6 Kent County... 6 Elgin County... 6 Niagara Regional Municipality... 7 Lambton County... 7 LIMITING FACTORS AND THREATS... 7 SPECIAL SIGNIFICANCE OF THE SPECIES... 7 EXISTING PROTECTION OR OTHER STATUS... 8 SUMMARY OF STATUS REPORT... 8 TECHNICAL SUMMARY... 9 ACKNOWLEDGEMENTS LITERATURE CITED BIOGRAPHICAL SUMMARY OF THE AUTHOR AUTHORITIES CONSULTED List of figures Figure 1. Acorn and leafy branch of Shumard Oak... 3 Figure 2. North American distribution of Shumard Oak... 4 Figure 3. Canadian (Ontario) distribution of Shumard Oak... 5

9 SPECIES INFORMATION Name and classification Scientific name: Quercus shumardii Buckl. Synonym: Quercus texana Buckl.; Quercus schneckii Britt. Common name: Shumard Oak Family: Fagaceae (Beech family) Major plant group: dicot flowering plant Description A large tree with massive limbs and an open, wide-spreading canopy. Older specimens have a heavily buttressed trunk that is covered with dark grey furrowed bark. The bark of younger limbs has smooth light grey bark. Branchlets are reddish or greyish brown; terminal buds are oval, pointed and grey. The leaves are 5-7 lobed with the lobes cut more than half way to the midrib; the upper surface is lustrous and the lower has conspicuous tufts of hair in the axils of the veins. Leaves turn a deep wine red in the fall. Acorns are about 2.5 cm long and enclosed by a shallow flat-topped grey cup (Figure 1). Figure 1. Acorn and leafy branch of Shumard Oak (Susan Laurie-Bourque, courtesy of Canadian Museum of Nature). In a study of Shumard Oak in Essex County, Morsink & Pratt (1984) suggest that some of the known sites of the oak may in fact represent hybrids with other members of the Red Oak/Black Oak group. Waldron (pers. com., to M. Oldham, 1998) disagrees and thinks that few of the sites are hybrid trees and for those that are there are good Shumard Oak trees nearby. 3

10 DISTRIBUTION Global range Shumard Oak occurs in the United States from Indiana and North Carolina south to Texas and northern Florida Isolated outliers occur in southern Pennsylvania, Kentucky, and Virginia but it is largely absent from the Appalachians (Waldron et al., 1987) (Figure 2). Figure 2. North American distribution of Shumard Oak (Fowells, 1965). Canadian range The Canadian range is restricted to southwestern Ontario in the counties of Essex, Kent, Elgin, Lambton and in the Niagara Regional Municipality (Figure 3). 4

11 Figure 3. Canadian (Ontario) distribution of Shumard Oak. Habitat requirements HABITAT Shumard Oak is a component of the Deciduous Forest Region of Canada. It requires rich, moist, poorly-drained clay and clay loam soil in deciduous woods or alone fencerows (Waldron, 1984). The forest canopy should be relatively open to permit regeneration (Waldron et al., 1987). Protection/ownership Two Shumard Oak populations occur in conservation areas in Essex County and another occurs in a conservation area in Kent County, however, most sites occur on private property or along road allowances. BIOLOGY Little specific information has been compiled on the biology of this species. Like other oaks, this species requires full sunlight for seedling establishment. These 5

12 conditions are met, particularly, at sites where the trees occur along fencerows and along roadsides. Shumard Oak also regenerates through its ability to sprout from stumps resulting from the brushing activities along fencerows. POPULATION SIZES AND TRENDS Thorough inventories have not been undertaken to determine the full extent and distribution of Shumard Oak within southwestern Ontario, however, several people have searched the five known counties/regional municipalities at various times and recorded tree size and numbers of trees. Most sites consist of single, relic trees along fencerows or in fields. Regeneration is reported at some sites where the oak occurs in woods or occasionally in open fields. Fencerow trees are sometimes cut down during fenceline brushing operations, but the oak is able to re-sprout from the base and thus at least persist at such locations. There are presently only about 40 records of occurrences with the total number of trees likely being <<1000 and may not even exceed 250. Essex County The original status report documented 13 specimen-based localities and 15 localities based on sight records that together showed a fairly widespread distribution in the county. When abundance information was recorded most sites consisted of a single relic tree (Waldron et al., 1987). Since that time, there have been six new specimen records, two of which fill out the range in the southeast portion of the county (Oldham, 1998). Abundance information was only recorded for three of the sites: one consisted of only a single tree, several trees occurred at a second site and at the third site, Shumard Oak was a dominant tree along a fencerow (Oldham, 1998). Morsink & Pratt (1984) estimate that there may be 500 scattered Shumard Oak trees in Essex County. Some of these trees however, may be hybrids (Morsink & Pratt, 1984). Kent County Five sightings were originally reported in the southwestern portion of the county. Since then, there has been one new specimen record from the same general area (Oldham, 1998). Several trees occur here in the Wilson Conservation Area. There are also several trees across the road just outside the Conservation Area. Elgin County A specimen record had been reported from the southwest comer of the county, however no such record is listed in Waldron et al. (1987). There is a new specimen record (1993) from the West Elgin Natural Area Complex that is near the mapped record in the status report (Oldham, 1998). There is no abundance information for this site. 6

13 Niagara Regional Municipality No records are shown from this area in the original status report. Waldron et al. (1987) show two locations and there are two additional sites in the NHIC database (Oldham, 1998). Only one site has abundance information and the oak at that site is "locally common" (Waldron et al., 1987). Lambton County The original status report did not report any records from this county. Waldron et al. (1987) show four locations and there is one additional site in the NHIC database. Two sites consist of a single tree; at one site the oak is "locally frequent; one site has "just a few trees"; and one site lacks abundance information. Detailed site information has been provided to the Co-chair of the Species Specialist Committee for Plants and Lichens (COSEWIC). LIMITING FACTORS AND THREATS Many of the sites of Shumard Oak occur in fencerows, fields, or along roads. Such isolated trees are at risk from fencerow brushing and field clearing. Large forest-grown trees are at risk from logging. Potential habitat for Shumard Oak, other than along fencerows and roadsides, is quite limited due to its occurrence in counties that have such limited forest cover due to past clearing for agriculture. The largest number of Shumard Oak sites occur in Essex County that has less than 3% of its forests intact (Waldron et al., 1987). Fencerows are sometimes removed completely in order to create larger fields for more efficient farming and this removes habitat for Shumard Oak (Waldron, 1984). Shumard Oak is a large and conspicuous tree that is very similar to other members of the Red Oak/Black Oak group, such as Red Oak (Quercus rubra), Black Oak (Quercus velutina), Pin Oak (Quercus palustris), and Hill's Oak (Quercus ellipsoidalis). This similarity could cause Shumard Oak to be overlooked and inadvertently cut down as a more common species. SPECIAL SIGNIFICANCE OF THE SPECIES The species is considered to be well adapted to its region of occurrence in Ontario (Waldron, 1984) and is potentially useful for planting in parks as is the common red oak. 7

14 EXISTING PROTECTION OR OTHER STATUS Since the designation of Shumard Oak as a vulnerable species in Ontario, no measures are known to have been taken to enhance its chances for survival. Two Shumard Oak populations occur in conservation areas in Essex County and another occurs in a conservation area in Kent County, however, most sites occur on private property or along road allowances. SUMMARY OF STATUS REPORT When the status of vulnerable was assigned in 1984, Shumard Oak was known from numerous sites in Essex and Kent Counties, and one location in Elgin County. Since that time, it has been discovered at several sites in Lambton County and in the Niagara Regional Municipality. Nonetheless, the geographic distribution is still very restricted in Ontario. Many of the locations consist of single trees in fencerows, fields, or along roadsides. Most of these sites are very vulnerable and show little or no regeneration. Three sites occur in protected areas. At present, there are only about 40 records of occurrences based on specimens collected within four counties (Essex, Kent, Elgin, Lambton) and in the Niagara Regional Municipality. The total number of trees is likely <<1000 and may not even exceed

15 TECHNICAL SUMMARY Quercus shumardii Shumard Oak Occurrence: Ontario chêne de Shumard Extent and Area information extent of occurrence (EO)(km²) >5000 specify trend (decline, stable, increasing, unknown) stable are there extreme fluctuations in EO (> 1 order of no magnitude)? area of occupancy (AO) (km²) perhaps <50 specify trend (decline, stable, increasing, unknown) stable? are there extreme fluctuations in AO (> 1 order no magnitude)? number of extant locations <40 specify trend in # locations (decline, stable, increasing, stable unknown) are there extreme fluctuations in # locations (>1 order of no magnitude)? habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat Population information generation time (average age of parents in the population) (indicate years, months, days, etc.) number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values) total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period) are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)? is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant / year)? list each population and the number of mature individuals in each specify trend in number of populations (decline, stable, increasing, unknown) possibly slight decline in habitat availability Unknown (production of acorns may not begin until trees are >25 years old) <<1000 and likely fewer than 250 perhaps stable no no but localities are clumped in two main regions of southwestern ON no precise figures are available perhaps stable with new trees located due to increased search effort no are there extreme fluctuations in number of populations (>1 order of magnitude)? Threats inadvertent loss from roadside brushing of shrubbery and lack of recognition of distinctness from red oak 9

16 Rescue Effect (immigration from an outside source) Low (Canadian occurrences are somewhat disjunct from the main range in the USA) does species exist elsewhere (in Canada or outside)? USA status of the outside population(s)? widespread in south-central USA is immigration known or possible? not likely would immigrants be adapted to survive here? yes is there sufficient habitat for immigrants here? yes Quantitative Analysis 10

17 ACKNOWLEDGEMENTS Mike Oldham, Botanist, Natural Heritage Information Centre, Peterborough, provided background information and a listing of known Shumard Oak records with details of recent confirmations. Funding for the preparation of this status report provided by the Canadian Wildlife Service, Environment Canada. LITERATURE CITED Fowells, H.A Silvics of forest trees of the United States. U.S. Department of Agriculture, Forest Service, Agriculture Handbook No Morsink, W.A.G. and P.D. Pratt Shumard Oak, Quercus shumardii, in Essex County, Ontario. Canadian Field-Naturalist 98: Oldham, M.J Element Occurrence records of Shumard Oak (Quercus shumardii) from the database of the Natural Heritage Information Centre, Ontario Ministry of Natural Resources, Peterborough. 43 pp. Waldron, G.W Shumard Oak (Quercus shumardii) new to Ontario. The Plant Press 1:54. Waldron, G.W Status report on the Shumard Oak Quercus shumardii in Canada. Committee on the Status of Endangered Wildlife in Canada. Canadian Wildlife Service, Ottawa. Unpublished report. 22 pp. Waldron, G.W., S.W. Aboud, J.D. Ambrose, and G.A. Meyers Shumard Oak, Quercus shumardii, in Canada. Canadian Field-Naturalist 101: BIOGRAPHICAL SUMMARY OF THE AUTHOR David J. White has a B.Sc. in biology and has been conducting natural area inventories and evaluating the status and significance of rare plants for more than 25 years. He began doing field surveys in 1972 for the International Biological Program. From 1973 to 1983, David was employed by the Canadian Museum of Nature as a research technician. During that period he co-authored a number of publications on rare plants, including the Atlas of the Rare Vascular Plants of Ontario. From 1984 to the present, David has worked as a self-employed life science consultant. He has completed projects ranging from natural area inventories and evaluations to reports on invasive species. David has previously written COSEWIC Status Reports on three species and authored or co-authored Update Status Reports on eight other species. AUTHORITIES CONSULTED Data on localities were provided by Mike Oldham from the Natural Heritage Information Centre, Peterborough, ON. 11