Sage Church
Trees can’t escape like we can: How natural disturbances affect the lives of trees.
Massive ice storms have rocked the East coast and Texas in recent weeks and everybody knows about all about the vast human impacts of these storms. However, not many people stop to think about how ecosystems, and much specifically plants are affected by these storms, and other natural disturbances. Trees and branches falling over and breaking constantly during and after ice storms, and with the possible increase of large storm events due to climate change it is important to know what kind of lasting impacts they could have on a forest ecosystem. A review article was written on this very topic in Nova Scotia, Canada, focusing on how major natural disturbances affect the trees and the ecology of forests in Nova Scotia. Trees are looked at because they are large and out in the open, and they are the basis of the ecosystems in which they reside. The natural disturbances reviewed for their effects on forest ecosystems in Nova Scotia included, but were not limited to, insect infestations, fire, wind, ice storms, disease, and drought.
The forests of Nova Scotia are largely pines, spruce, and other conifers with a sprinkling of deciduous trees (trees that lose all their leaves at once, such as most oaks and maples). This makes these forests especially susceptible to spruce budworms and Spruce Beetles (Dendroctonus rufipennis Kirby), pictured below, which can destroy entire areas (Anthony et al., 2020). These beetle outbreaks were actually determined to be one of the worst natural disturbances in Nova Scotia’s forests. Once a stand of trees is infested by these beetles it can be very quickly destroyed.
One of the other most severe disturbances in this area is lightning damage and fires. Due to the prevalence of pines and spruce in the area there is an increased risk of fire. Humans have also increased risks of fires in many areas because fire is a natural part of the ecosystem and we often prevent it. This leads to a build up in flammable material and increased fire danger. When the balance of the system is tipped like this it can cause issues because there is a fine line between beneficial fires and destructive fires.
The final major disturbance in the forests of Nova Scotia is wind. High winds coupled with the right soil type, recentness of precipitation, and other factors can be very damaging to trees. It can cause lots of damage to the limbs and branches, but whole trees will also break or fall over in high winds. Some will even be completely uprooted especially if the ground is soft. Tropical storms and hurricanes are always a big deal, but they can be especially bad here because tropical storms only occur about every four years and hurricanes every seven (Anthony et al., 2020).
A few other slightly more straight forward and less impactful disturbances are ice storms and droughts. Droughts can have lasting effects on the forest ecosystem, but if they are not extremely severe they will most likely not result in a severe die off of trees. Ice Storms can also be very damaging to trees. They break branches and up root whole trees, but it can almost be like a natural pruning of the forest. However, they can cause some large trees to fall as illustrated in the image below.
This information is vital to the proper management and restoration of our forests. It helps us understand the trends and ebb and flow of the forest system, as well as what needs to be done to help protect the forests from nature disturbances that are intensified by human activity. Disturbances that are more of an anomaly than the norm in an area are more devastating than those that happen more frequently. Therefore, as stated in the review article hurricanes are infrequent in Nova Scotia and cause great harm to the forests of that area. However, ice storms are fairly regular and less harsh on the ecosystem of Nova Scotia. Somewhere like Florida or Texas, or even North Carolina that gets plenty of hurricanes they may not have as great of an impact, but ice storms are a huge shock there. It’s all about balance in forest systems and the more anomalies and severe weather events we have the worse the damages on forests will be. Therefore, even though these are all natural disturbances there are still anthropogenic impacts that intensify them, and it is our responsibility to find the solutions to these impacts. This directly ties back inot climate change, and our efforts to slow and stop the anthropogenic causes of climate change.
References
Anthony, T., MacLean, D., Neily, P., Stewart, B., Quigley, E., Basquill, S., Boone, C., Gilby, D., & Pulsiferet, M.. 2020. A review of natural disturbances to inform implementation
of ecological forestry in Nova Scotia, Canada. Environmental Reviews. 28(4): 387-414.