When a tree is cut down, a common question arises regarding the ultimate fate of its root system. Understanding the biological processes that occur after a tree is felled helps clarify how roots respond and what their potential for survival or regrowth may be. This exploration delves into the immediate and long-term effects on tree roots once the main trunk has been removed.
The Immediate Impact on Tree Roots
When a tree is cut, the main energy source, photosynthesis, stops immediately because the leaves are removed. This cessation of photosynthesis means the tree can no longer produce new sugars. While the top portion of the tree is gone, the roots do not die instantly. They remain alive for a period, sustained by the energy reserves stored within their tissues.
These stored energy reserves are primarily in the form of starches. Without the continuous supply of new sugars from the canopy, the roots begin to deplete these stored starches. This depletion means roots, though alive, cannot support new growth or extensive repair, leading to a decline in viability over time.
Root Survival and Potential for Regrowth
The duration that roots survive after a tree is cut varies considerably, influenced by factors such as the tree species, its age, and the amount of energy reserves it had accumulated. Some tree species can regrow from the remaining stump or root system. This phenomenon, called suckering or coppicing, involves new shoots sprouting from dormant buds located on the stump or within the root collar. These buds, previously suppressed by the main trunk, can develop into new stems.
For instance, certain deciduous trees like maples, oaks, and willows often produce suckers. These new shoots draw upon stored energy in the root system and, if allowed to grow, can establish a new, multi-stemmed tree. Additionally, in some cases, the roots of a cut tree may be grafted to the roots of a neighboring living tree of the same species. This natural grafting allows severed roots to receive nutrients and water, extending their lifespan even without their own canopy.
Strategies for Root Management
Several strategies exist to manage or eliminate remaining tree roots. One common mechanical method is stump grinding, where a specialized machine grinds the stump and upper root flare into wood chips. This process effectively removes the visible stump and breaks up surface roots, preventing regrowth.
Another approach involves the application of herbicides directly to the freshly cut stump. This chemical treatment is absorbed and transported into the root system, accelerating the death and decay of the roots. This method prevents suckering and promotes rapid root decomposition.
Alternatively, one can simply allow the roots to decay naturally over time. This biological decomposition, facilitated by soil microorganisms, can take several years depending on root system size and environmental conditions. While slower, this method requires no active intervention.