This beautiful old forest is very biodiverse. Many of the trees are truly majestic. Like most forests on steep north-facing slopes, this one has a significant component of white pine and hemlock, but Slim Jim Woods is dominated by hardwoods: oaks, hickories and maples. The biggest, tallest trees seem to be at the bottom of the slope; whether they are older or found better conditions there is not clear.
The slope is steep, gravelly and somewhat unstable. On steep slopes such as this one, the downslope movement of soil, water, solutes and organic matter, leads to a general pattern of increasing soil pH, soil fertility, and species diversity from top to bottom of the slope. One can readily observe the change in species diversity on this slope. The base is very species-rich, especially in herbaceous species, which are sparser and less diverse higher up.
Appalachian oak-hickory forest
A hardwood forest that occurs on well-drained sites, usually on flat hilltops, upper slopes, or south and west facing slopes. Dominant trees include one or more of red oak, white oak, and black oak. Mixed with oaks, are one or more of pignut, shagbark, and sweet pignut hickory. Common associates are white ash, red maple, and hop hornbeam. Small trees include flowering dogwood, witch hazel, shadbush, and choke cherry. Shrubs and groundlayer flora are diverse. Shrubs include maple-leaf viburnum, blueberries, red raspberry, gray dogwood, and beaked hazelnut.
Hemlock-northern hardwood forest
A forest that typically occurs on lower slopes of ravines, on cool, mid-elevation slopes, and at the edges of drainage divide swamps. Hemlock is a codominant species with one to three others: beech, sugar maple, red maple, black cherry, white pine, yellow birch, black birch, red oak, and basswood. Shrubs have low abundance, but striped maple may be present. Herbs characteristic of northern and montane areas are common.
Beech-maple mesic forest
A hardwood forest with sugar maple and beech codominant. Found on moist, well-drained soils, on north and east facing slopes, and on gently sloping hilltops of any aspect, this type rarely occurs in ravines. Common associates are basswood, American elm, white ash, yellow birch, hop hornbeam, and red maple. Characteristic species in the sub- canopy are musclewood, striped maple, witch hazel, hobblebush, and alternate-leaved dogwood. There typically are few herbs and shrubs, but tree seedlings may be abundant. There are many spring ephemerals.