Download Succession of the GHS-OWL site Stage 1 Primary Succession

Succession of the GHS-OWL site
Stage 1 Primary Succession – (This was not a part of the succession of the OWLS area being studied. It
has been 18 years since the OWLS site stopped being farmed to crops and left to grow naturally.)
Stage 2 Pioneer Species – “When a plowed field is abandoned, it represents a new habitat for plant and
animal species to colonize, but because it is basically bare soil, it is a stressful habitat for many
plants… This environment is first colonized by a group of species called pioneer species. Pioneer
species are usually characterized by having… the ability to utilize resources rapidly, allowing them
to grow and reproduce quickly. Many of them are included in that group of species commonly
called weeds. Among the earliest species to arrive are ragweed, crabgrass and foxtail. After a year
or two, these are joined by various species of asters. These pioneer species change the
environment; as they die, dead plant material (plant litter) accumulates on the soil, and this helps
to hold water in the soil.”
(Another abundant plant at this stage, in the area of OWLS that is a drainage ditch, was Marsh Elder.)
Stage 3 Secondary Succession – “When an old field is three to ten years old, perennial grasses and
herbs gradually replace the annual and biennial pioneer species. A typical dominant perennial herb
in old fields of eastern North America is goldenrod. Many of the grasses are bunch grasses, which
grow in clumps; little bluestem (Andropogon) is common in New Jersey fields. The perennial herbs
out compete the pioneer species, which are unable to germinate and grow under the dense
perennial cover. After about ten years shrubs begin to reach noticeable size. Early in this stage the
field will be a mixture of perennial grasses and small shrubs. A common old field shrub is sumac....
As the shrubs grow they shade the ground and many of the shade-intolerant perennial grasses and
herbs become less numerous. Eventually the filed will be nearly uninterrupted growth of tall
shrubs. Vines such as poison ivy…may also grow among the woody species.
(One of the most abundant grasses at this stage, in the area of OWLS that was not in the drainage ditch,
was Bermuda grass.)
Stage 4 Climax Species - Eventually tree seedlings begin to sprout among the shrubs. The seedlings of
most tree species of the mature community are shade-tolerant, so that they can begin to grow
under the cover of shrubs. As the seedlings grow, the field will become a mixture of shrubs and
young trees, and it will begin to resemble a woodland. As the tree species that dominate the
mature community begin to reach their maximum size, they shade out the shrubs beneath. In a
mature forest, other shrubs which are shade-tolerant will grow beneath the canopy trees; maple
leaf viburnum and flowering dogwood are the most common ones in this area. Succession is a
continuous process and does not always proceed in neat states.” Source @ Old Field Succession
(The climax community of a wetter climate grassland ecosystem in our area is composed of bunch grasses
like Big Bluestem, Small Bluestem, and Indian Grass. The drier areas in the study have move towards
climax communities of Buffalo Grass and Side Oats Grama. Native trees like the Cottonwood and Willow
have also sprouted up. In our area, trees will eventually move in and start to become a climax species
instead of these perennial grasses. Until the last 150 years, prairie fires have prevented that from
happening here. In 2008, we started controlled burns to help prevent that from happening. The results
were almost immediate. The following summer saw a dramatic change in the flora towards the climax
grasses listed above and a great decrease in the amount of Bermuda Grass, Marsh Elder, Ragweed, and so
on.)
(See Pictures of GHS – OWLS succession and controlled burn dates below)
Plowed Field: Purchased GHS Property
Stage 2 Pioneer Species: Marsh Elder and Foxtail
Stage 3 Secondary Succession: Bermuda Grass
Stage 4 Climax Species: Indian Grass
Dates Prescribed or Controlled burns were conducted
in the GHS-OWLS
March 2008
March 2009
March 2010
March 10, 2011
March 13, 2012
March 14, 2013
March 12, 2014