Disturbed Ecosystem Plants

"Weeds"

• Plants that are generally referred to as "weeds" tend to be opportunistic species that will take advantage of ecosystem disruptions and move in to fill the gap. These plants are very important because they are hardy, fast-growing and adaptable, and will quickly cover bare ground, thereby reducing erosion and soil compaction. Over time, these primary succession species will give way to more permanent, secondary succession plants, and this process will eventually lead all the way back to the ecosystem that was originally disturbed.

Clearcuts

• Clearcuts are environments in which the successions that follow disturbance of an ecosystem are very clear. Following the destruction of the forest, the first plants to move in are usually opportunistic plants such as blackberries, raspberries, vines, and hardy grasses. These provide rich browsing opportunities for bears, deer, porcupines and other wildlife that spread their seeds farther by eating them. Eventually, trees such as birch and pine will grow up, and, if the environment is temperate enough, these trees will eventually be choked out by larger, longer-living trees such as oaks and maples.

Vulnerable Ecosystems

• Some ecosystems have difficulties regenerating with hardy plants after they suffer severe damage. Tropical forests and desert landscapes may take many years to recover from clearcutting, intentional burning, excessive soil compression, or plowing, because they didn't evolve to cope with these threats. In tropical forests, most of the nutrients in the ecosystem are contained within the biomass of the trees themselves, so when these trees are cut and removed, the soil quickly declines, and the area may even become desertified. Usually, the plants that move in are low-growing brushes that are very hardy. It may take centuries for destroyed tropical forest ecosystems to regenerate to a climax state.