Forests are land dominated by trees, in addition to being habitats for a plethora of biodiversity, they provide a range of ecosystem services for humans (as mentioned in previous blog posts). For example, these trees are photosynthetic organisms that produce the essential oxygen for the respiration of all living things on earth. Trees also help to prevent flooding with their well-established root system, allowing water to infiltrate into the ground hence reducing surface runoff and soil erosion. There are also many more undiscovered uses of plants with medicinal potentials. Forests are also home to many species of living things which are also responsible for regulating the forest ecosystem. Each individual organism has its role, such as decomposers breaking down organic matter, recycling the nutrients back into the soil, or insects that help pollinate flowers to facilitate the reproduction of plants.
Pollution of the environment produces a whole range of negative impacts towards forests, and more importantly affects their ability to provide these crucial ecosystem services (Beier, Caputo, Lawrence & Sullivan 2017). In the naturally occurring environment, there are many naturally occurring chemical processes that result in chemicals being released into the environment. The variety of lives on earth has taken millions of years to evolve and adapt to these processes, however, due to human activities, there is disruption to these processes. Some of the consequences are the increase in the concentration of chemicals being released into the environment due to alteration of the environment, and the introduction of new chemical compounds into the environment that further disrupts ecosystem processes (Taylor, Johnson & Andersen, 1994).
The above figure shows the impact of acidification on ecosystem services. The black arrows indicate impacts caused by processes, the solid blue lines indicate positive relationships, and the dotted blue lines negative relationships. The figure shows that the deposition of nitric and sulfuric acid resulting in a decrease in soil pH. When the soil pH is lowered, there is an increase in the amount of H+ ions in the soil pore water. When H+ ions are in abundance, this “forces” the heavy metals that were already bound to the negatively charged soil particles to dislodge, giving up the bond to the more chemically reactive H+ ions. This results in the soil pore water having a higher heavy metal content. The heavy metal concentrated water will eventually get washed into a nearby water body where many aquatic organisms live. The heavy metals that are in the water body will then get bioaccumulated in the bodies of fishes. As a result, there will be negative impacts on recreational fishing as fishermen are increasingly aware of this bioaccumulation, hence reducing these activities (Jones et al., 2014).
This post has shed some light on the brief chemical processes that are results of environmental pollution, and how it affects forest ecosystems and ultimately their ecosystem services, which in turn affects us, humans. Though brief, this post is a precursor for our understanding of the more complex processes that occur in the four spheres of Earth which will be covered in our next post.
Stay tuned for more!
References:
Air Pollution Information System. (n.d.). Ecosystem Services and air pollution impacts. Retrieved September 05, 2020, from http://www.apis.ac.uk/ecosystem-services-and-air-pollution-impacts
Beier, C. M., Caputo, J., Lawrence, G. B., & Sullivan, T. J. (2017). Loss of ecosystem services due to chronic pollution of forests and surface waters in the adirondack region (USA). Journal of Environmental Management, 191, 19-27. doi:10.1016/j.jenvman.2016.12.069
Jones, L., Provins, A., Holland, M., Mills, G., Hayes, F., Emmett, B., . . . Harper-Simmonds, L. (2014). A review and application of the evidence for nitrogen impacts on ecosystem services. Ecosystem Services, 7, 76-88. doi:10.1016/j.ecoser.2013.09.001
Taylor, G. E., Johnson, D. W., & Andersen, C. P. (1994). Air pollution and forest ecosystems: A regional to global perspective. Ecological Applications, 4(4), 662-689. doi:10.2307/1941999