Old-field Succession Photo Gallery

Map of successional plots
Five plots are designated to illustrate the varied stages of old-field succession. Two are renewed by tilling every 10 years; two others, every 40 years; and the remaining plot is tilled every year that one of the others is not tilled. Starting dates of plots with the same rotation period are staggered as shown by the initial starting dates on this map.
A newly disked successional plot
Prior to planting crops, land that is farmed is tilled.
Annual weeds invade
If a tilled field is left alone for a month or so, it becomes green with annual weeds.
Blackberries and dog fennel dominate
Five years after a field is abandoned, blackberries and dog fennel may dominate.
Loblolly pines begin to dominate
At 15 years, loblolly pines are beginning to dominate, but once they form a closed canopy, their seedlings will have too little sun to develop, setting the stage for the shade-tolerant seedlings of hammock hardwoods.
Understory of fast-growing hardwoods
At 40 years, an understory of fast-growing hardwoods, especially sweetgum, is apparent beneath towering loblolly pines. If succession is not interrupted, the site will eventually support a hammock, and loblolly pines will only occur where they have quickly colonized openings left by wind-felled or lightning-killed large trees.
Johnson grass control
At the start of NATL, the old-field area was dominated by stands of non-native grasses so thick that succession, as described above, could not occur. Beginning in 1996, RoundUp® herbicide has been used to control Johnson grass, elephant grass, and cogan grass. This picture shows extensive stands of Johnson grass killed in September 1996.
Spot treatment
The stands of exotic grasses were much reduced in 1996, but repeated spot treatments, especially of Johnson grass (shown here), were needed in 1997 and are still used occasionally.

More on the old-field ecosystem and its management can be found on the Old-Field Succession Ecosystem page.

More photos:
Semi-annual photos of plots A, B, C, D, 2007-date.
Gridpoint photos, 1997, 2007.