Ecological dynamics
The Steep Sandy Ridges ecological site contains a number smaller sites. The aspect of steeper slopes determines the microclimate variation. South facing slopes are warmer and drier, thus much more drought-prone than north-facing slopes, west-facing slopes, with afternoon sun, are slightly warmer and drier than eastern exposure. The drier slopes are likely to be less productive. Also, upper slopes are drier than their lower counterparts. The lower side slopes, while still steep, seem to be more productive, probably because they more sheltered. The summit areas (ridgetops) of Steep Sandy Ridges are less sloping but they are more exposed to wind, with it's drying effect and higher potential for damage to trees. The white pines on ridgetops often show pronounced flagging, that is, more branches on the downwind side of the tree. So while this site is distinctive in it's own right due to steepness, it can broken down into small components that are have different productivity classes and disturbance regimes.
State 1
Reference State
The Reference State of Steep Sandy Ridges has two phases--the Jack Pine-Pin Oak Phase and the White Pine-Red Oak Phase--plus these phase tended to intergrade because they occurred simultaneously on different parts of the site but often in close proximity. In addition, the Jack Pine-Pin Oak Phase was succeeded by the White Pine-Red Oak Phase because the latter species are longer-lived and more shade tolerant. Moreover, jack pine and pin oak stands are regenerated by fire and this site has areas that are more or less protected from by their physiography, portions of the have natural fire breaks such as the lower slopes of the leeward side of the ridge. The Reference State exists as mere remnants of its former extent.
Community 1.1
Jack Pine-Pin Oak Phase
This phase can represent both early and late successional stages (the so-called edaphic climax) on this site; this is due to highly pronounced microsite variability. Small patches on this site can resemble Sand Barrens ecological sites, other patches are more mesic. The driest parts of this site occur on unprotected south to southwest facing slopes and also have little to no silt, clay, or humus in the topsoil. Several dozen feet away, soil and slope conditions are likely to be different and the plants respond accordingly. Small areas of barren conditions are not the dominant condition, but they do reduce overall site productivity and probably the species richness of the site as well.
Community 1.2
White Pine-Red Oak Phase
The dominant species in this phase are also tolerant of dry conditions, but they are have a broader range of adaptation and are more competitive on somewhat better sites than jack pine or pin oak. However, they are not as fire adapted as aforementioned species, but they have evolved with fire and fire plays a part in the ecology of these species. In general, white pine and red oak occur on and are thus indicative of the more productive areas of this site.
State 2
Cutover State
The Cutover State is by far the most common condition on this site. The pre-logging era vegetation on this site was mostly mature pine and oak forest. Both types of trees were in demand at the time. Pines were the most commonly logged species because of their usefulness as light-weight, moderate-strength building lumber, oaks were second in demand as sawlogs. This resulted in extensive clear-cuts that are now, one hundred years later, starting to resemble the former condition on some of these sites.
Community 2.1
Aspen-Paper Birch Phase
Following the clear-cut, aspen was the most abundant tree, paper birch was second. Of the two aspen species, bigtooth aspen is the most adapted to this site because of its lower nutrient and moisture requirements. This does not preclude quaking aspen clones from establishing on this site, but the stems self-prune at a higher rate and mature trees are more prone to fungal infection and are thus shorter-lived. Birch trees have been known to form pure stands on this site in the absence of viable competition. Both of these species give way over time to the more shade tolerant and longer-lived oaks and pines. However, jack pine is seldom present in second growth forests given its fire-dependent characteristics.
Community 2.2
Red Pine-Red Oak Phase
This phase is the modern-day edaphic climax for this site. Red pines supplant white pines because red pine seed has become more abundant than white pine seed and this species is well-adapted to dry sites. Red oak is also hardy, somewhat shade tolerant, and red oak acorns are widely dispersed by wildlife.
State 3
Disturbed/Invaded State
The Disturbed/Invaded State is less common on this ecological site than on other closely related sites, but given the prominent landforms on which this site is located, disturbance is readily identified. The disturbance is largely man-made, such as logging activities or accelerated erosion on bare soil; natural disturbances include drought, fire, wind damage, insect herbivory, and disease outbreaks. Insect herbivory spreads disease, but herbivory alone can extirpate some species. These disturbances open the canopy, expose the forest floor to sunlight and increase the risk of soil erosion. While these sites are prone to disturbances, many invasive species do not thrive here due to steep, thin soils; but that also slows recovery of the forest canopy. The main effect of disturbance is lower site productivity; a longer recovery time from disturbance is a property inherent to this site.
Community 3.1
Weeds-Aspen Phase
Native pioneer species found on this site include bracken fern, raspberry, blackberry, sweet fern, Canada goldenrod, staghorn sumac, quaking aspen, bigtooth aspen, and pin cherry. Lichens and mosses are important in establishing soil conditions favorable to the growth of those higher plants. Non-native weedy species that become serious pests include spotted knapweed, Canada thistle, burdock, and ragweed; weeds of lesser concern include common mullein, yellow and orange hawkweeds, dandelion, brome grass, birdsfoot trefoil, bindweed, tansy, plantain, sheep sorrel, bladder campion, sweet clover, horseweed, redtop and quackgrass.
Community 3.2
Aspen-Bracken Phase
As the canopy gradually closes, with mainly bigtooth or quaking aspen, weeds are shaded out. Although some weeds like spotted knapweed are pernicious and produce toxins that inhibit the growth of other plants, most are susceptible to being out-competed. Bracken fern is the common understory plant at this stage; bracken also has allelopathic properties (i.e. toxic to other plants). This phase seems to persist for long time. Although aspen trees are not lived, aspen clones are persistent and they will re-sprout in sunlit areas.
State 4
Converted State
The Converted State is common on most upland ecological sites, less so on this one because steepness limits alternatives. However, this site is an excellent source of sand and gravel, and is often preferred because of the ease of access. Landforms such as eskers are especially utilized. Plantations are less common on this site because of difficulties in preparing and planting steep ground, however these sites are often included in larger plantations.
Community 4.1
Red Pine Plantation
Red pine is planted because it is highly productive, even on marginal sites. Also red pine is highly uniform in its genetic characteristics which ultimately produces a uniform stands of trees. Many of these plantations are reaching maturity. Older plantations that have been well-managed through thinning resemble natural stands in terms of structure and species richness.
Community 4.2
Borrow Pits
This site has limitations for development due to steepness but is used commonly for borrow pits, roads and trails (especially on the summit) and cut and fill areas. Borrow pits, when active, are miscellaneous (non-soil) areas that lack vegetation. However, when inactive, they re-vegetate, albeit at highly variable rates. Some areas will produce a pioneer/weed species community in the first growing season, other areas will remain barren for years to come because the exposed sediments hold zero available water, heat up too much and lack any primary plant nutrients. Eventually the extreme conditions are softened by accumulation of organic matter transported to the site by wind, water, and wildlife.
Transition 1
State 1 to 2
Most of these sites were part of the great cutover of the logging era (1870-1920). It would very difficult to find a Steep Sandy Ridges ecological site that was left untouched by loggers
Restoration pathway 1
State 3 to 2
Canopy closure can reduce the weed problem. There no known methods to eliminate earthworms, if they could be eliminated, they could readily re-infest a site.
Transition 3
State 3 to 4
A disturbed area is a prime candidate for conversion to another land use if the opportunity arises. On Steep Sandy Ridges sites, agriculture is less desirable, but borrow pits are common. It is easier to excavate ridges than flat areas. Tree planting, however, is not easier.
