Pinus strobus Lm Eastern White Pine Pinaceae Pine family G. W. Wendel and H. Clay Smith Eastern white pine (Pinus strobus), also called transpiration is between 430 and 710 mm (17 and 28 northern white pine, is one of the most valuable trees in), of which 56 to 68 percent occurs in the warm in eastern North America. Before the arrival of white season. There is a moisture surplus in all seasons. men, virgin stands contained an estimated 3.4 billion Average depth of frost penetration ranges from m3 (600 billion fbm) of lumber. By the late 1800’s about 25 cm (10 in) in the southern Appalachians to most of those vast stands had been logged. Because more than 178 cm (70 in) in parts of central and it is among the more rapid growing northern forest northern Minnesota. Average annual snowfall ranges conifers, it is an excellent tree for reforestation from 13 cm (5 in) in northern Georgia to more than projects, landscaping, and Christmas trees and has 254 cm (100 in) in New England and southern the distinction of having been one of the more widely Canada (51). planted American trees. Soils and Topography Habitat The major soil orders found in the white pine Native Range range are Inceptisols, Ultisols, Spodosols, Entisols, and Alfisols (14,50,66). In New England the impor- Eastern white pine (fig. 1) is found across southern tant subgroups are excessively drained or somewhat Canada from Newfoundland, Anticosti Island, and excessively drained sandy deposits or stratified sand Gasp6 peninsula of Quebec; west to central and and gravel deposits. Most of the parent materials are western Ontario and extreme southeastern glaciofluvial deposits-subgroups Typic Udorthents, Manitoba; south to southeastern Minnesota and Typic Haplorthods, and Typic Udipsamments; glacial northeastern Iowa; east to northern Illinois, Ohio, tills-subgroups Lithic Dystrochrepts and Lithic Pennsylvania, and New Jersey; and south mostly in Haplorthods; or weathered igneous rocks (loose crys- the Appalachian Mountains to northern Georgia and talline fragments mainly from weathered Conway northwestern South Carolina. It is also found in granite&subgroup Lithic Haplorthods (42). western Kentucky, western Tennessee, and In northern Minnesota, Eutroboralfs, Haplorthods, Delaware. A variety grows in the mountains of Udipsamments, and Hapludalfs are among the most southern Mexico and Guatemala. common of the great groups (2). They are similar to the soils of New England and are more or less freely Climate drained and have developed on glacial outwash or till material. The climate over the range of white pine is cool Dystrochrepts, Fragiodults, and Normudults are and humid. The distribution of white pine coincides the major great groups occupied by white pine in the reasonably with that part of eastern North America central Appalachian Mountains (45). These soils are where the July temperature averages between 18” weathered from acid shales and sandstones, either in and 23” C (65” and 74” F). place (residual soils), deposited on lower slopes (col- Annual precipitation ranges from about 510 mm luvial material), or along stream terraces (alluvial (20 in) in northern Minnesota to about 2030 mm (80 material). The soils are generally well drained and in) in northwestern Georgia. In the area surrounding have a coarse loamy to a fine loamy texture. the Great Lakes, about two-thirds of the precipita- Soils within the range of white pine are derived tion occurs during the warm season, April to Septem- from granites, gneisses, schists, and sandstones, and ber. Elsewhere, half of the precipitation occurs less commonly from phyllites, slates, shales, and during the warm season. The length of the growing limestones. In the northern part of the Lake States season ranges from 90 to 180 days. and southern Canada, white pine is usually confined Throughout the range of white pine, precipitation to soils derived from basalts, gabbro, diabase, and is about 1 to 1.5 times the evaporation from shaded granites (70). Most of the area was covered by the free water surfaces (71). Annual potential evapo- Wisconsin glaciation so the soils are young and have weakly developed profiles (67). In New Hampshire, white pine is found on granite-derived soils and on The authors are Research Forester (retired), and Project Leader metamorphic crystalline schists (42). From central Northeastern Forest Experiment Station, Radnor, PA. Pennsylvania south and in southwestern Wisconsin, 476 Pinus O"'2bo' 600 KILOMETER Figure l-The native range of eastern white pine. the soils are much older, generally are finer textured, regenerates naturally, competes easily, and can be and have well developed profiles. managed most effectively and economically (40,47). White pine grows on nearly all the soils within its On medium-textured soils (sandy loams), it will out- range (70, but generally competes best on well produce most other native commercial species in both drained sandy soils of low to medium site quality. volume and value (47). White pine also grows on fine These soils permit fair growth of white pine but not sandy loams and silt-loam soils with either good or hardwoods. On these sandy sites, white pine impeded drainage when there is no hardwood com- 477 Pinus strobus petition during the establishment period-as on old oaks on the poor soils (71). In a comparison of site fields and pastures, burns, and blowdowns. It has index and growth of 10 species in the southern Ap- been found on clay soils and on poorly drained or palachians, white pine exceeded all species in very poorly drained soils with surface mounds. It can growth, except on the best sites, where yellow-poplar be very productive on these sites but usually occurs outranked it in height only In New England, white only as individual trees or in small groups (47). This pine frequently pioneers on abandoned agricultural pine should not be planted in heavy clay soils. Poorly land but only on the well-drained to excessively drained bottom land sites and upland depressions drained deposits-outwash, sandy tills, and shallow are also poor choices for planting (6). bedrock. White pine may form part of the climax At various places within white pine’s range, site (edaphic) on the driest of these materials or may quality has been related to combinations of soil and alternate with oak (42). topographic characteristics such as texture and In New England and New York, white pine thickness of the A and B horizons, depth and per- generally grows at elevations between sea level and meability of the underlying rock or pan, depth to the 460 m (1,500 ft), occasionally higher. In Pennsyl- water table, natural drainage class, topographic posi- vania, the elevation ranges from 150 to 610 m (500 tion, slope percent, and aspect. In the unglaciated to 2,000 ft) (71). In the southern Appalachians, white regions of Ohio and central Indiana, site quality for pine grows in a band along the mountains between white pine increases as the soil becomes coarser in 370 and 1070 m (1,200 and 3,500 ft) above sea level, texture and declines as the moisture equivalent and occasionally reaching 1220 m (4,000 ft). In Pennsyl- wilting percentage increase in the A and B horizons vania and the southern Appalachians, most white (71). But thickness of the A horizon had the greatest pine is found on northerly aspects, in coves, and on influence on rate of growth. stream bottoms. Elsewhere, aspect seldom restricts In Massachusetts white pine site quality increased its occurrence (71). with the increase in silt and clay fraction of the A horizon, with higher pH value of the B or C horizon, Associated Forest Cover with increased stone and gravel fraction greater than 2 mm (0.08 in) in the A horizon, with greater White pine is a major component of five Society of nitrogen content in the A horizon, and with higher American Foresters forest cover types (70): Red Pine percent organic matter in the B horizon (46). In (Type 15), White Pine-Northern Red Oak-Red Maple general, the higher site indices are associated with (Type 20), Eastern White Pine (Type 21), White the poor soil drainage classes. On reclaimed soils, Pine-Hemlock (Type 22), White Pine-Chestnut Oak white pine should not be planted on sites with a pH (Type 51). None of these are climax types, although of less than 4.0 (6). the White Pine-Hemlock type may just precede the In New Hampshire, the average height of climax hemlock types, and Type 20 is very close to a dominant and codominant trees increased as the soil climax or an alternating type of climax on the sandy tended to be less well drained (7,71). Site produc- outwash plains of New England (42). White pine oc- tivity in Maine showed the following responses: in- curs in 23 other forest types: crease with a reduction in soil drainage; increase with pH increases in surface mineral horizons; 1 Jack Pine decrease with increased content of stones larger than 5 Balsam Fir 0.6 cm (0.25 in) in the C horizon, but increase with 14 Northern Pin Oak the contents of stones in surface horizon; increase 18 Paper Birch with thickness of the A horizon; increase with soil 19 Gray Birch-Red Maple depth to a bulk density of 1.40 or greater; increase 23 Eastern Hemlock with increasing availability of soil moisture in the 24 Hemlock-Yellow Birch upper 76 cm (30 in) of soil (59). 25 Sugar Maple-Beech-Yellow Birch 26 Sugar MapLBasswood In the southern part of its range, white pine grows 30 Red Spruce-Yellow Birch best on soils along rivers and streams and grows 31 Red Spruce-Sugar Maple-Beech somewhat more slowly on well drained sites (22).