Index of Species Information

SPECIES:  Platanus occidentalis


SPECIES: Platanus occidentalis
AUTHORSHIP AND CITATION : Sullivan, Janet. 1994. Platanus occidentalis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : PLAOCC SYNONYMS : Platanus occidentalis var. attenuata (Fern.) Sarg. [50] SCS PLANT CODE : PLOC COMMON NAMES : sycamore American sycamore plane tree buttonball tree TAXONOMY : The currently accepted scientific name for sycamore is Platanus occidentalis L. (Platanaceae) [13,35,48,50]. There are no accepted infrataxa. The London plane tree (P. xacerifolia [Ait.] Willd.) is a hybrid of Oriental plane (P. orientalis) and sycamore and perhaps includes a number of backcrosses [50,78]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : Sycamore is listed by the State of Maine as a species of special concern-possibly extirpated [26].


SPECIES: Platanus occidentalis
GENERAL DISTRIBUTION : The range of sycamore extends from southwestern Maine west to extreme southern Ontario, southern Wisconsin, Iowa, and extreme eastern Nebraska; south to south-central Texas; and east to northwestern Florida and southeastern Georgia. It also occurs in the mountains of northeastern Mexico [30,35,50]. Sycamore has become naturalized to some extent from plantations outside of its native range, chiefly in southern Maine, southern Michigan, southern Minnesota, and eastern and southern Iowa [35]. ECOSYSTEMS : FRES15 Oak - hickory FRES16 Oak - gum - cypress FRES17 Elm - ash - cottonwood FRES18 Maple - beech - birch STATES : AL AR CT DE FL GA HI IA IL IN KS KY LA MD ME MA MI MN MO MS NE NC NH NJ NY OH OK PA RI SC TN VA VT WV WI ON MEXICO BLM PHYSIOGRAPHIC REGIONS : 14 Great Plains KUCHLER PLANT ASSOCIATIONS : K098 Northern floodplain forest K099 Maple - basswood forest K100 Oak - hickory forest K101 Elm - ash forest K103 Mixed mesophytic forest K106 Northern hardwoods K112 Southern mixed forest K113 Southern floodplain forest SAF COVER TYPES : 23 Eastern hemlock 24 Hemlock - yellow birch 25 Sugar maple - beech - yellow birch 26 Sugar maple - basswood 27 Sugar maple 37 Northern white-cedar 39 Black ash - American elm - red maple 60 Beech - sugar maple 61 River birch - sycamore 62 Silver maple - American elm 63 Cottonwood 65 Pin oak - sweetgum 87 Sweetgum - yellow-poplar 91 Swamp chestnut oak - cherrybark oak 92 Sweetgum - willow oak 93 Sugarberry - American elm - green ash 94 Sycamore - sweetgum - American elm 95 Black willow 96 Overcup oak - water hickory 97 Atlantic white-cedar SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Sycamore is found in quantity only in bottomland forests, particularly of elm-ash-cottonwood (Ulmus spp.-Fraxinus spp.-Populus deltoides) types as defined by Shifley and others [66], and cottonwood-willow (Salix spp.) types. It usually occurs singly or in small groups [78]. Sycamore is found occasionally along intermittent streams within upland stands of oak-hickory (Quercus spp.-Carya spp.) communities. It is a major pioneer species in the floodplains of large rivers [74]. In the Southeast pure stands of 40 to 100 acres (16-40 ha) are sometimes formed; it rarely forms extensive pure stands in the northern parts of its range [78]. In the northern states sycamore is rarely the dominant species; it increases (replacing silver maple [Acer saccharinum]) with decreasing latitude [27]. Sycamore is listed as a dominant or indicator species in the following publications: 1) The natural forests of Maryland: an explanation of the vegetation map of Maryland [14] 2) The natural communities of South Carolina [58] 3) Land Classification in the Blue Ridge province: state-of-the-science report [55] 4) Forest management of floodplain sites in the northeastern United States [56] 5) Management of bottomland hardwoods [61] 6) Ecological communities of New York State [63] 7) Classification and evaluation of forest sites on the northern Cumberland Plateau [68] 8) Classification and evaluation of forest sites on the Natchez Trace State Forest, State Resort Park, and Wildlife Management Area in west Tennessee [69]


SPECIES: Platanus occidentalis
WOOD PRODUCTS VALUE : Sycamore is a valuable timber tree; its wood is hard, with a twisted and coarse grain, but not very strong [13,30,76]. It is used for furniture, interior trim, boxes, pulpwood, and particle and fiber board [13,30]. Carey and Gill [19] rated sycamore as only fair (their lowest rating) for fuelwood. Sycamore is planted in short-rotation intensive culture systems for use as fuel or pulp [72,78]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Sycamore does not provide much food for wildlife, although the seeds are eaten by some birds including the purple finch [82,84], goldfinch, chickadees, and dark-eyed junco [84], and by muskrat, beaver, and squirrels [13,76,82,84]. Sycamore is rated as medium in suitability for waterfowl habitat and low in suitability as deer or turkey food [3]. Carey and Gill [19] rated sycamore as only fair (their lowest rating) for wildlife use. In Arkansas, sycamore is of minor importance as deer browse [84]. As sycamores age, they may develop hollow trunks which provide shelter for a number of wildlife species; some large, old individuals have formed cavities large enough to be used as dens by black bear [84]. Cavity nesting birds include the barred owl [2], eastern screech-owl, great crested flycatcher [37], and chimney swift [84]. Wood duck use sycamores as nest trees [29]. The bottomland forests in which sycamore occurs are very important wildlife habitat, sheltering numerous animal species including wood duck, other waterfowl, upland game birds, and deer [57]. In Indiana, riparian forests in which sycamore occurs are important habitat for the endangered Indiana bat, which uses these areas for nursery colonies [10]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : The nutritional value of sycamore "grab samples" was reported as follows: 25 percent dry matter, 13.7 percent crude protein, and 67 percent total digestible nutrients [17]. Foliage samples were 18.2 percent lignin, 2.67 percent calcium, 0.38 percent magnesium, 0.12 percent phosphorus, and 1.65 percent potassium [65]. COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : Sycamore occurs naturally on disturbed sites if there is sufficient moisture for seedling establishment. It occasionally occurs in mostly pure, well-stocked stands on naturally regenerated strip-mined lands in the central states. In Missouri, it is often found in pure stands or in mixtures with other hardwoods that pioneer on spoil banks. In Alabama and Tennessee, waterway disposal sites (material removed from stream channels) seeded with grass mixtures were invaded by sycamore [38]. In Tennessee, channelization projects resulting in degrading streambanks were colonized by sycamores during the early recovery period [44]. Sycamore saplings were present in small numbers on unreclaimed limestone quarries in Oklahoma [64]. Between 1928 and 1975, sycamore was one of the 10 most commonly planted hardwoods on surface-mined soils in Indiana [11]. Sycamore is recommended for planting on all types of strip-mined land in many northeastern and central states [78]. In Florida, sycamore was planted on a phosphate mine site for a wetland reclamation project [51]. In Tennessee, beaver impoundments were drained and planted with sycamore; sycamore was chosen for its ability to tolerate saturated soils [42]. OTHER USES AND VALUES : Sycamore is planted as a street tree [83], although it is highly susceptible to ozone damage [25] and is susceptible to foliar injury and reduced growth when exposed to salt spray [73]. The London plane tree is more resistant to air pollutants and is more commonly planted as a street tree [28]. Sycamore has been planted in shelterbelts [16]. OTHER MANAGEMENT CONSIDERATIONS : Sycamore is a valuable timber species that can be regenerated from natural seed sources, by planting, or by coppice systems. Seed: Sycamore invades bottomland old fields when adequate seed sources are present [3,59]. It oftens seeds in on clearcuts; good initial establishment from natural seed sources requires some site preparation [79]. Its potential for establishment from direct seeding is unknown [3]. Plantation: Sycamore usually shows good initial capture of planting sites [49]. Sycamores interplanted with herbaceous legumes were larger than control plants 6 years after legume establishment [36]. On mined sites interplanting sycamore with the nitrogen-fixing European black alder (Alnus glutinosa) doubled sycamore height and diameter growth over that of control plants [77]. Site characteristics, rather than site preparation method, had the most pronounced effect on sycamore height growth [24]. However, Hunt and Cleveland [43] reported sycamore growing on disc-cultivated sites showed better growth than with other treatments. Sycamore does not establish well in dense herb or shrub cover [77]. Clatterbuck and Burkhardt [21] reported on the effects of various mixtures and spacings for cherrybark oak (Quercus falcata) and sycamore plantations in Arkansas. Coppice: For short-rotation intensive culture systems, sycamore yield is influenced by site, fertilizer, spacing, and rotation [80]. Sycamore has good coppice regeneration potential although it may not be sustainable over many rotations. Geyer [33] reported that sycamore died after two coppice harvests in Kansas. A high percentage of stumps sprout, regardless of stump size or time of harvest. However, dormant season cuts produce larger and heavier sprout clumps than cuts during the growing season [5,78]. Insects and Diseases: Natural stands of sycamore have few lethal diseases [22]; disease problems occur mostly in plantations. Important diseases include anthracnose and eastern mistletoe (Phoradendron spp.) [78]. There have been some reports of a potentially serious disease of sycamore in Illinois and adjacent states, and possibly spreading to Tennessee, Mississippi, Louisiana, and Alabama. This disease has been attributed to attacks by various organisms on environmentally stressed trees; it is not attributed to a single cause [22]. There are no insects of economic importance in natural stands, although problems with insects occur in landscaping trees [78]. Large sycamores sometimes develop wind shake, a wood defect that reduces its economic value [78]. Sycamore is susceptible to ice damage [78]; of six trees examined after an ice/sleet storm in Missouri and Illinois, only one escaped major damage [23]. Under powerlines, sycamore regrowth was appreciably reduced with pressure-injected malic hydrazide or daminozide [12].


SPECIES: Platanus occidentalis
GENERAL BOTANICAL CHARACTERISTICS : Sycamore is a native, deciduous tree. Although not the tallest, it is amoung the tallest trees of eastern deciduous forests [78]. Mature heights range from 60 to 120 feet (18-37 m) [9,83]. Reported diameters range from 2 to 6.6 feet (0.6-2 m) [83]. The bark of young trunks has small scales. Bark at the base of large trunks is deeply furrowed and up to 3 inches thick (7.6 cm) [83]; on the upper portions of the trunk the bark exfoliates in patches, leaving areas of inner bark exposed [30,78]. The leaves are 4 to 10 inches (10-25.4 cm) long, often as broad or broader than they are long [83]. Sycamores form widespread, strongly branched root systems [78]. The fruit is a plumed achene [52]; numerous fruits are tightly aggregated into a ball-shaped fruiting head 0.8 to 2 inches (2-5 cm) in diameter [9,13]. Sycamore is characterized by rapid growth throughout its life; it is also long lived (over 250 years) [78]. A sycamore measuring 140 feet (43 m) tall and 120 inches (305 cm) dbh has been reported; a specimen from Indiana was reported as 168 feet (51 m) tall and 33 feet (10 m) in circumference. Open-grown individuals can achieve a crown spread of 100 feet (30 m) or more [78]. A survey of big trees in seven mid-southern states reported that the second and fourth largest trees (of all species) were sycamores. The largest sycamore in these states was a Tennessee tree 140 feet tall (42.67 m) and 65.9 inches (167.4 cm) dbh, with a circumference of 207 inches (525.8 cm), the largest circumference of any tree in these states [53]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : Sycamore is monoecious. Plantation-grown sycamores are usually sexually mature in 6 to 7 years. Natural stands of sycamore usually produce appreciable numbers of seed at approximately 25 years; optimum seed production occurs from 50 to 200 years of age. Seed production is not dependable from trees over 250 years old. Good seed crops are produced every 1 to 2 years [78]. Sycamore seeds are dispersed by wind and water [83]. They have a relatively rapid rate of descent for light seeds; the estimated lateral travel distance in a 6 mile per hour (10 km/hr) breeze is 223.7 feet (62.8 m) [52]. Since seed dispersal occurs at a time of year when water levels are declining after spring floods, water dispersal often results in seed deposition on muddy flats that are highly conducive to germination [44,83]. Sycamore seeds do not require any pretreatment for good germination [9]. They do require very moist conditions for good germination and are tolerant of inundation [83]. Soaking seeds in water for up to 32 days did not reduce germination rates; the seeds did not germinate during the soaking period [40]. Sycamore seeds germinated at a significantly higher percentage in light than in dark [54]; they do not germinate well in heavy litter or in deep shade [78]. Sycamore seeds did not germinate in laboratory tests at temperatures lower than 59 degrees Fahrenheit (15 deg C); they germinated well at temperatures between 59 and 86 degrees Fahrenheit (15-30 deg C), with maximum emergence at 68 degrees Fahrenheit (20 deg C) in the wetter part of a moisture gradient [18]. Sycamore seedlings require direct sunlight for good growth and establishment [78]. At the end of their first year, sycamore seedlings on clay soil showed better height growth in partial shade than in full sun. On alluvial soil or loess, height growth was better in full sun [7]. Seedling roots penetrate the soil quickly and grow deeper in loess soils than in alluvial or clay soils [78]. Young sycamore stems sprout readily from the stump; sycamore is not a vigorous epicormic sprouter. Sycamore can be vegetatively propagated by cuttings [78]. SITE CHARACTERISTICS : Sycamore is primarily a species of alluvial soils along streams and in bottomlands, but occurs occasionally as a pioneer on drier upland slopes [13,30.78]. It occurs on a wide variety of soils, including both sands and clays [57]. Its best growth occurs on sandy loams or loams with a good supply of ground water but it also occurs on wet muck, shallow peat and other, more poorly drained bottomland soils [78]. Sycamore occurs on a variety of wet sites, including shallow swamps, sloughs, and very wet riverbottoms where soil is saturated 2 to 4 months during the growing season [39]. Sycamore seedlings survived almost 2 months of continuously waterlogged soils [46]. In a greenhouse experiment, after experiencing 60 days of completely waterlogged soils, about half of current-year seedlings died shortly after their removal from the water; none died with shorter treatment periods [41]. Sycamore is more tolerant of poorly drained soils in the northern parts of its range. It was given an adaptation value of 7.5 (out of a maximum of 10) for moisture tolerance [1]. Sycamore has a recommended lower pH range of 4.0 to 4.5 [77] Sycamore is rated as moderately tolerant of flooding. In the Northeast, sycamore occurs on sites with greater than 98 percent probability of flooding in any given year [56]. In Illinois, sites that experience flooding approximately 3 months of the year are dominated by silver maple, sycamore, and green ash (Fraxinus pennsylvanica var. lanceolata). These sites are usually flooded before the growing season; sycamore is intolerant of flooding during the growing season and will die if the entire tree is inundated for more than 2 weeks [78]. Saplings may be more resilient than mature trees due to their higher sprouting capacity; Baker [4] reported that even though 4 weeks of flooding appeared to have killed 65 percent of sycamore saplings, 90 percent of the saplings were alive at the end of one growing season following flooding. Most of them had only been top-killed and subsequently sprouted from the root crown [4]. Seedlings are less tolerant of flooding than larger plants simply because they are more likely to be completely covered by water during active growth. Only 28.8 percent of scyamore seedlings survived complete inundation for 5 days during a June flood as compared to a survival rate of 88.9 percent for unflooded seedlings [46]. The elevational range of sycamore extends from sea level to 1,000 feet (305 m) in the northern parts of its range and to 2,500 feet (762 m) in the southern Appalachians [13,78]. SUCCESSIONAL STATUS : Facultative Seral Species Sycamore is intolerant of shade. Seedling growth is greatly reduced in deep shade (defined as 5 percent of full sunlight) [45]. Sycamore occurs in forest types that are pioneer, transitional, subclimax, and climax [31,78]. Sycamore will pioneer on sand and gravel bars and other newly formed land, often persisting through later seres, such as sugar maple (Acer saccharum)-bitternut hickory (Carya cordiformis), particularly on wet sites [78]. It is an occasional pioneer on upland oldfield sites, particularly in the central parts of its range. In Illinois, sycamore was the most common tree species present in the seed rain or as seedlings in local old fields [18]. In southern Illinois, 1- to 5-year-old sycamore seedlings were most common on newly formed land, then on old fields, in cottonwood-willow communities, and in soft mixed-hardwoods (elms, ashes, birches [Betula spp.], silver maple, and red maple [Acer rubrum]); there were no seedlings present in hard mixed-hardwood communities (oaks and hickories) [85]. Sycamore usually replaces willows (Salix spp.) and eastern cottonwood (Populus deltoides). The sycamore-sweetgum-American elm type usually succeeds cottonwood on river fronts, but may pioneer on heavily cutover sites or old fields in bottomlands. This type may persist as a subclimax type where repeated disturbances such as flooding occur. It is usually succeeded by swamp chestnut oak (Quercus michauxii)-cherrybark oak or sweetgum-willow oak (Liquidambar styraciflua-Q. phellos) [31]. In the North Carolina Piedmont, sycamore and river birch (Betula nigra) usually replace alders (Alnus spp.) and willows on small islands or spits in streams after the land becomes stable and moderately well drained [78]. Sycamore and river birch are usually followed by elms (Ulmus spp.), ash (Fraxinus spp.) and red maple [78]. In Kentucky, an island that formed in 1913 was occupied by a pure stand of eastern cottonwood 30 to 40 feet tall by 1922. Trees coming in among the cottonwoods included sycamores [67]. The presence of sycamore in upland climax forests may be a function of disturbance rather than a function of moisture or drainage regime; its establishment in these woods may require larger disturbances than those produced by single or multiple tree falls [8]. SEASONAL DEVELOPMENT : Sycamore flowers appear in May in the northern parts of its range, and as early as late March in the South. Late spring frosts will kill flowers, leaves, and twigs [78]. The fruits ripen from September to October or November, and usually remain on the tree over winter, breaking up or falling off the following spring from February through April [9,78].


SPECIES: Platanus occidentalis
FIRE ECOLOGY OR ADAPTATIONS : Sycamore is a member of bottomland hardwood communities that do not usually experience crown fires. Fire seasons occur approximately every 5 to 8 years; summer droughts extended into fall create conditions for ground and surface fires which can cause damage and mortality. Bottomland fires usually move rapidly along the surface, consuming shrubs and herbs and usually killing all tree reproduction under about 10 years of age. Larger trees suffer bark scorch which causes wounds that create points of entry for rots, stains, and insects; this results in reduced vigor and delayed mortality. Under extreme conditions large trees may be killed outright [61]. The only reported occurrence of sycamore in a historically fire-maintained community is its presence in low numbers on a blue ash-oak (Fraxinus quadrangulata-Quercus spp.) savanna in Kentucky. It was not stated whether the presence of sycamore was synchronous with frequent surface fires, or if it became established in this area since the cessation of fire [15]. FIRE REGIMES : Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes". POSTFIRE REGENERATION STRATEGY : Tree with adventitious-bud root crown/soboliferous species root sucker Secondary colonizer - off-site seed


SPECIES: Platanus occidentalis
IMMEDIATE FIRE EFFECT ON PLANT : Surface fires in the bottomland forests in which sycamore occurs readily kill saplings and seedlings of all species. Larger trees are wounded by fire; fire wounds act as vectors of disease, increasing rot and decreasing plant vigor [57,61]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Sycamore is unlikely to be a major pioneer on burned sites. On bottomlands, rapid growth of competing weeds and vines would reduce sycamore establishment, and burned upland sites are usually too dry for good seedling establishment. Only one published report of sycamore seedlings on a burned site is available. In North Carolina, an oldfield loblolly pine (Pinus taeda) stand experienced both surface and crown fire. Sycamore seedlings were present in small numbers on the crown fire plots, indicating that moisture and light conditions were sufficient for sycamore seedling establishment [60]. Top-killed sycamore will sprout; it is unlikely, however, that a fire severe enough to kill the aboveground portions will not also kill the shallow roots. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : In the Southeast, the usual fire season is fall; fire years occur when the usual summer drought extends into autumn and early winter. Most fires are accidentally caused by humans [61]. Prescribed fire is not recommended for southeastern bottomland forests in which sycamore occurs; aside from damaging and killing trees, fire reduces soil organic layers, leading to site degradation. Following fire, weeds and vines flourish on exposed sites, increasing competition with tree seedlings that may establish after fire [57,61]. Sycamore had a significantly lower proportion of its stem weight in bark than any of the other species tested. In the soft hardwoods group (red maple, sweetgum, sycamore, and yellow-poplar [Liriodendron tulipifera]), sycamore had the highest average total-tree moisture content of any species tested [20]. A formula to estimate recoverable heat energy in wood or bark fuels is available [86].


SPECIES: Platanus occidentalis
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