Wooded Uplands Key

This is a dichotomous key to wooded upland natural communities

Dichotomous keys work by making one of two choices. Start at number 1, and determine which of the descriptions best suits what you are looking at. Then click on the link under the "go to" column to take you to the next choice, and ultimately to the natural community description.

Number	Description	Go To
1	Conifer forests and woodlands: broad-leaved trees <25% cover	2
1	Broad-leaved or mixed forests and woodlands: broad-leaved trees >25% cover	24
2	Conifer forests: tree cover usually >65%, lower layers generally more sparse than canopy (except for dense patches of tree regeneration in canopy openings); area lacks a well-developed low shrub layer of lowbush blueberry, velvet-leaf blueberry, black huckleberry, sheep laurel, or black chokeberry ; substrate various, but often mineral soil, usually not a thin organic layer over bedrock	3
2	Conifer woodlands: tree cover usually <65%, as low as 20% (occasionally to ~80%), trees more-or-less open grown; low shrub layer of lowbush blueberry, huckleberry, sheep laurel, and/or chokeberry prominent (>15% cover), or sometimes bracken fern prominent (>10% cover) instead; ground cover may feature fruticose lichens; substrate bedrock, with a thin layer of mostly organic soil typically <15 cm deep	14
Conifer Forests
3	Hemlock and/or pines dominant (near the coast, northern white cedar occasionally co-dominant)	4
3	Spruce and/or fir dominant	8
4	Hemlock dominant; red spruce, white pine, and/or cedar often present, sometimes co-dominant; stands may be either coniferous or mixed, strongly coniferous stands with very sparse herb and bryoid layers	Hemlock Forest
4	Hemlock not dominant	5
5	Northern white cedar dominant; rocky hillslopes	White Cedar Woodland
5	Pines dominant	6
6	Jack pine dominant, or co-dominant with black spruce; known only from western Maine	Jack Pine Forest
6	Red pine or white pine dominant; more widespread	7
7	White pine dominant (highest basal area); red spruce, hemlock, and/or northern white cedar often present and may be nearly co-dominant	White Pine - Mixed Conifer Forest
7	Red pine dominant (highest basal area); red spruce, white pine, (or coastally, northern white cedar) often present, may be nearly co-dominant	Red Pine - White Pine Forest
8	Balsam fir dominant, heart-leaved paper birch and/or mountain ash often common, subalpine or coastal	9
8	Red and/or black spruce dominant	10
9	Coastal; white spruce often present	Maritime Spruce - Fir Forest
9	Montane; white spruce absent	Fir - Heart-leaved Birch Subalpine Forest
10	Variable canopy closure; black spruce or red-black hybrids often present; red pine occasionally present; heath shrubs prominent in herb layer (often >25% cover, may be very dense); usually on level, well-drained to xeric glacial deposits, sometimes with patches of saturated-soil and peat moss pockets in hummocky topography	Spruce - Heath Barren
10	More or less closed canopy with mixtures of red spruce, black spruce, or other conifers; heath shrubs and herbs sparse (less than 20% cover), or if more, then with northern wood-sorrel, bluebead lily, tree regeneration may be dense in gaps	11
11	Red spruce, black spruce, or hybrids on level, poorly drained soils; wetland plants and peat mosses may be frequent, bryoids abundant (>50% cover)	Spruce - Fir - Cinnamon Fern - Forest
11	Upland sites on till, bedrock, or talus, with red spruce or white spruce dominant; yellow birch and balsam fir may be occasional; wetland plants absent except in small seeps and ravines	12
12	Yellow birch often present and may form >25% cover. Herb layer with moderate to extensive cover of herbaceous species (often in patches), including northern wood-sorrel, bluebead lily, rose twisted-stalk, or mountain wood-fern; bryoid layer >20%, with feather-mosses prominent; northern/montane areas	Spruce - Fir - Wood-sorrel - Feather-moss Forest
12	Yellow birch, if present, forms <25% cover. Herbs and dwarf shrubs sparse (<10% cover each); herb layer may include dense regeneration patches	13
13	Coastal (within mi. of the coast); white spruce often present, especially near coastline; bryoid layer >15% cover and not dominated by broom-mosses	Maritime Spruce - Fir Forest
13	Widespread inland, may be near-coastal; both herb and bryoid layers very sparse; what bryoids are present include a large proportion of broom-mosses and pincushion moss	Spruce - Fir - Broom-moss Forest
Conifer woodlands
14	Northern white cedar the dominant tree species, usually twice as abundant as any other tree species	White Cedar Woodland
14	Other species dominate tree layer	15
15	On talus, spruce dominant	Spruce Talus Woodland
15	On bedrock (or, less commonly, sand or glacial till), various dominants	16
16	Mixture of conifer species, each <50% cover; or woodlands dominated by white pine or red pine	17
16	Pitch pine, jack pine, or spruce each ≥60% cover	18
17	Canopy dominated by red spruce or white pine (>60% cover), or by a mixture of conifers with none dominant, red spruce usually present	Red Spruce - Mixed Conifer Woodland
17	Red pine dominant in canopy	Red Pine Woodland
18	Jack pine dominates canopy	Jack Pine Woodland
18	Other conifers dominate canopy; jack pine usually absent altogether	19
19	Black spruce the most abundant canopy tree	20
19	Pitch pine the most abundant canopy tree	21
20	Woodlands on bedrock, often coastal or on upper summits inland	Black Spruce Woodland
20	Woodlands or forests on level or gently sloping till, occasionally with a thick organic layer	Spruce - Heath Barren
21	Open woodlands on ledge; trees often stunted	Pitch Pine Woodland
21	Open woodlands or sometimes almost closed forest, on sandy soil	22
22	Dunes or backdune areas along the immediate coast; bayberry almost always present	Pitch Pine Dune Woodland
22	On glacial deposits, not dunes; inland or at least not at the immediate shoreline	23
23	Scrub oak extensive and locally dominant, making foot-travel difficult	Pitch Pine - Scrub Oak Barren
23	Scrub oak absent or sparse, foot-travel easier	Pitch Pine - Heath Barren
Broad-leaved or mixed forests and woodlands
24	Forest seasonally saturated and/or discharging groundwater for significant periods during the growing season	25
24	Forest not seasonally saturated or discharging groundwater	28
25	Forest on gentle to moderate slope or flat bench within upland setting; discharging groundwater for significant periods during the growing season; dominant trees include ashes, sugar maple, red maple, yellow birch, or hemlock; jewel-weed often present	Hardwood Seepage Forest
25	Forest may be saturated and flooded in the spring and adjacent to larger streams and rivers in a floodplain setting, or may be a somewhat elevated riverside terrace; ferns frequent	26
26	Floodplain forests with silver maple dominant and conifers absent or very sparse; usually along medium to large rivers. Herb layer includes ostrich fern and other ferns	Silver Maple Floodplain Forest
26	Other hardwoods dominant (not silver maple)	27
27	High floodplain or terrace forests along medium to larger rivers in southern and central Maine, most often with sugar maple or red oak dominant, sometimes with yellow birch or ash dominant; on larger rivers this type is often found adjacent to but at slightly higher elevation than silver maple floodplain forests	Hardwood River Terrace Forest
27	Floodplain with balsam poplar dominant or co-dominant with American elm and ash; northern Maine	Balsam Poplar Floodplain Forest
28	Open broad-leaved woodlands (tree cover <65%) with birches, red oak, red maple, or ironwood dominant (Ironwood - Oak - Ash Woodlands may occasionally have a forest canopy >65% but they will key here: check description in couplet 31 below)	29
28	Broad-leaved or mixed closed-canopy forests (tree cover >65%) or mixed woodlands	32
29	Hillside or low summit woodlands dominated by red oak, without much ironwood or sugar maple, and with a heath shrub and bracken fern understory	Oak - Pine Woodland
29	Not as above	30
30	Open to closed canopy woodlands on glacial till or outwash; early successional deciduous trees dominant (aspen, white/gray birches, red maple), red oak <40% cover (rarely up to 50%), conifers <30% cover	Aspen - Birch Woodland/Forest Complex
30	Open woodlands on talus or thin-soiled hilltops rather than till or outwash	31
31	Woodlands on talus or thin-soiled hilltops and upper slopes; ironwood and oaks dominant (the former as either canopy or subcanopy), sugar maple occasionally common, and basswood often present but not abundant; with enriched site indicators e.g. round-leaved dogwood, herb Robert, hepatica, columbine, blue-stem goldenrod, and wide-leaved sedge	Ironwood - Oak - Ash Woodland
31	Woodlands on talus; birches the most abundant tree; oaks and ironwood may be present but less abundant; enriched site indicators absent or very incidental	Birch - Oak Talus Woodland
32	Broad-leaved component dominated by northern hardwood species (beech, yellow birch, sugar maple, red maple); red oak <30% cover	33
32	Broad-leaved component dominated by oak, white or gray birch, red maple, shagbark hickory, and/or aspen, rather than northern hardwood species	39
33	Mixed forests with conifers >25% cover	34
33	Deciduous forests, conifers <25% cover	37
34	Red spruce the dominant conifer	Spruce - Northern Hardwoods Forest
34	Hemlock or white pine the dominant conifer	35
35	Hemlock the dominant conifer	Hemlock Forest
35	White pine the dominant conifer	36
36	One or more northern hardwood species (beech, yellow birch, sugar maple) mixed with red oak and conifers; northern hardwood cover >15%	Red Oak - Northern Hardwoods - White Pine Forest
36	Canopy almost entirely red oak and white pine (occasionally red spruce), sometimes mixed with red maple; northern hardwoods sparse	Oak - Pine Forest
37	Some combination of beech, sugar maple, red maple, and yellow birch dominates the canopy, with sugar maple always <50% cover; ash and basswood absent or very minor; herb layer rarely >40% cover except for tree seedlings; enriched site herbs absent	Beech - Birch - Maple Forest
37	Sugar maple dominant or co-dominant (≥50% cover); in southern or central Maine, white ash and/or basswood are usually present; herbs >40% cover	38
38	Several moderate rich site indicators are present, including doll's eyes, jack in the pulpit, grape fern, alternate-leaved dogwood, spikenard, and false Solomon's seal	Semi-rich Northern Hardwood Forest
38	In addition to the species noted above, numerous uncommon rich site herbs such as leatherwood, Dutchman's breeches, maidenhair fern, and blue cohosh, and flat sedge are frequent. Sites are typically small acreages in sheltered sites (coves) or where calcium-enriched soils have accumulate	Maple - Basswood - Ash Forest
39	Early successional deciduous trees dominant (aspen, white/gray birches, red maple), red oak <40% cover (rarely up to 50%), canopy closure variable from very open to almost closed; conifers <30% cover	Aspen - Birch Woodland/Forest Complex
39	Oaks >50% cover, or if less, then canopy cover >35% coniferous	40
40	White oak, chestnut oak, and/or hickories present; southern Maine	41
40	White oak, chestnut oak, hickories absent or virtually so; statewide	43
41	Chestnut oak dominant or at least common; open-canopy woodlands (<65% canopy)	Chestnut Oak Woodland
41	Other oaks dominant	42
42	White oak and red oak dominate canopy; hickory essentially absent	White Oak - Red Oak Forest
42	White oak and red oak present and may be dominant, but shagbark hickory (and sometimes bitternut hickory) also present	Oak - Hickory Forest
43	Closed-canopy forests with northern hardwood species (usually beech or sugar maple) >20% cover, may be co-dominant with red oak	Red Oak - Northern Hardwoods - White Pine Forest
43	Beech, sugar maple, and white ash <10% cover each	44
44	Woodland structure: open canopy (<60% closure, occasionally more), trees well-spaced and often stunted; well-developed herb layer (>15% cover of dwarf shrubs and >5% cover of herbs), with graminoids often abundant and typical closed-forest species essentially absent	Oak - Pine Woodland
44	Forest structure: canopy closure >70% and understory somewhat sparse, with dwarf shrubs much less than 15% cover; herbs include typical forest species such as Indian cucumber-root and wild-oats	Oak - Pine Forest

 

Back to Top