Ecological Processes in Ecosystems
Ecological processes are characterized by their dynamism and tendency to evolve continuously, leading to transformations in the composition and structure of the flora and fauna of a given ecosystem. Such a process is commonly referred to in scientific terms as succession, which, strictly speaking, should be defined as a consistent change in ecosystems in a given area over time (Chang & Turner, 2019). Generally, the main drivers of succession are the interactions between organisms and the environment within an ecosystem.
There are several essential preconditions for this biogeographic process to occur, whether it is an empty, uninhabited area (primary) that is repopulated with different species over time, or a previously biodiversity-rich area (secondary) that has undergone destruction and will consistently re-acquire new species of flora and fauna. Succession, thus, is a natural process realized through a sequence of changes in ecosystem structure and composition, regardless of the prerequisites for succession.
Neighborhood Ecosystem Analysis
A large number of animal and plant species are present in my neighborhood. Among the plants that I noticed during my observation are oaks, maples, conifers, mosses, and lichens, mostly near areas of high humidity. There is also a wealth of animal species: squirrels, many different bird species, street (stray) cats and dogs, and hedgehogs. The animals in the ecosystem should also include insects such as mosquitoes, flies, midges, spiders, and ants. The area’s ecosystem is also rich in bacteria, which live on rocks, plant and animal corpses, in puddles, and in the grass, but, due to their microscopic size, they are impossible to observe with the naked eye.
Like any other biological structure, the ecosystem in my neighborhood undergoes succession over time. A primary succession scenario is one in which the ecosystem has not yet been inhabited: no people, animals, or plants have lived in the area, and it is entirely pure, lifeless. Mosses and lichens initially colonize any ecosystem, as these taxa are adaptive and straightforward in terms of evolutionary structure and needs (Helmenstine, 2023). Plants of higher order may have colonized the area, including flowering species (oaks, maples) and conifers.
When the plant life proved rich enough and suitable for other species, the ecosystem could be expected to be populated by the first wild animals and insects. Without external interventions, such a forest could have become more mature and biologically diverse over time, as reflected in the ecosystem’s species balance. It is possible that such a forest was cut down at some point in history to build a city, upsetting the balance and introducing an external stimulus into a natural, well-established ecosystem.
There is, however, an alternative variant of succession that could (or will) occur via a secondary mechanism. In this case, it can be assumed that at some point in the future, the city will be destroyed, for example, through the spread of massive forest fires, war, or other means destructive to urban well-being. When the area previously occupied by the urban agglomeration becomes vacant, this may trigger successional processes. If the area were eradicated, it would lead to the same processes described in the last paragraph. If the city’s area were not reduced to zero, secondary succession could start from intermediate stages, for example, if higher-order plants survived.
In any scenario, succession would proceed through population-balancing mechanisms. These should include tools of the struggle for survival, such as predation, symbiosis, and competition between species for resources. Factors to be considered include external stimuli, such as alien species invasions or declining biodiversity.
For example, removing birds, squirrels, and herbaceous plants from an ecosystem to support stray cats may cause street cats to decline due to a lack of resources to survive. Conversely, if humans, street dogs, or bacteria are removed, this could lead to an increase in the cat population due to the lack of deterrents. Introducing invasive species into the ecosystem may increase the street cat population (mice or chickens) or decline if feral foxes or eagles are introduced.
References
Chang, C. C., & Turner, B. L. (2019). Ecological succession in a changing world. Journal of Ecology, 107(2), 503-509.
Helmenstine, A. (2023). Pioneer species definition and examples. Science Note.