What is Ecology?

The word Ecology comes from the Greek words oikos  meaning home, and logos  meaning study. It is the scientific study of the interactions between organisms and the environment.

There are different levels of ecological studies according to the scope. Figure 1 shows the hierarchy of ecological research.

Hierarchy of Ecological Research

1.) Organismal ecology - studies how the environment affects individual organism's structure, physiology, and behavior[1].

Research in organismal ecology mainly focuses on the adaptations that allows an individual to survive in a specific habitat [8]. Basically, an individuals reaction to the environment is being studied. Changes in the environment affects each individual species. They may adapt to the such changes, move to a different environment, or worse such individuals will die.

2.) Population ecology - studies the changes in population size as affected by environmental factors[1].

Naturally, organism grow and die[2]. In population ecology, the changes in population size (number of individuals)[8] and the factors that affect such changes are being studied [2]. A good example is the study of the Karner blue butterfly (Lycaeides melissa samuelis).

Karner blue butterflies are highly dependent on the presence of the plant called wild lupine (Lupinus perennis). This means that the distribution and density of this species of butterfly is influenced by the distribution and density of the wild lupine plant. Population ecologists interested on the distribution and abundance of the Karner blue butterflies would also study the factors affecting the decline of the wild lupine plant[8].

3.) Community ecology - studies interactions between populations affecting community structure and organization[1].

In a biological community, two or more populations of different species occupy the same geographical area[2]. Research in community ecology focuses on the process driving the interactions within and between species in the community and what consequences results from such interactions.

An example of interaction within species is competition. This may mean competition for a mate or competition for food.  Interaction between species can be predation, parasitism, competition, and mutualism [2][8].

4.) Ecosystems ecology - studies the interaction between organisms and the environment[1].

An ecosystem is basically composed of the biotic and abiotic factors. Research in ecosystems ecology mainly focuses on how the abiotic factors such as nutrients and energy are stored and move among organisms and the environment [8].

5.) Landscape (or seascape) ecology - studies exchanges of energy, materials, and organisms across multiple ecosystems[1].

In biology, a landscape is the unit of the earth which has a specific character. This may be vegetation structure, habitat type, soil type, etc. Research in landscape ecology focuses on the interactions between the temporal and spatial aspect of an area and the organisms within it[9].

6.) Global ecology - studies how the changes in the biosphere affect the behavioral distribution of organisms.

Research in global ecology studies the entirety of life (biotic) and life-support system (abiotic). Simply put, global ecology is the science of the Earth ecosystem[11].

Definition of terms

• abiotic - non-living factors (e.g. air, water, soil) of the environment affecting organisms and the functioning of ecosystems.
• biosphere -  the layer of the planet Earth in which life can exist. This covers up to 10 kilometers above sea level down to the depths of the ocean.
• biotic - living thing or living component in an environment.
• community - a group of population of different species interacting in a common location
• ecosystem - the community of organisms (biotic factors) in an area and the physical (abiotic) factors with which these organisms interact.
• landscape (or seascape) - in ecology this refers to the assemblages of different ecosystems (Bynum 2019).
• organism - an individual living thing that is able to respond to stimuli, grow, maintain homeostasis, and reproduce.
• population - a groups of individuals of the same species living in the same area at the same time.
• spatial scale - the distance between habitat patches relative to the dispersal distance of the organism[10].
• species - a group of closely related organisms of the same individuals with the ability to interbreed and produce fertile offsprings.
• temporal scale - habitat lifespan relative to the generation time of the organism[10].

References

[1]Bynum, N 2019. 17: Landscape Diversity. https://bio.libretexts.org/Bookshelves/Ecology/Book%3A_Biodiversity_(Bynum)/17%3A_Landscape_Diversity

[2]Mohanty S. 2017. The importance of studying ecology. Research and reviews: Journal of ecology and Environmental Science. Vol 5 (2); 10-13.

[3]Reece, J. B., Urry, L. A., Cain, M. L. 1., Wasserman, S. A., Minorsky, P. V., & Jackson, R. (2011). Campbell biology (Ninth edition.) Pearson Benjamin Cummings

[4]https://www.dictionary.com

[5]https://www.biodiversidad.gob.mx/v_ingles/planet/whatis_bios.html

[6]https://www.collinsdictionary.com/dictionary/english/biosphere

[7]https://www.biology-online.org/dictionary/Ecosystem

[8]https://courses.lumenlearning.com/wm-biology2/chapter/levels-of-ecological-research/

[9]https://www.forestresearch.gov.uk/research/landscape-ecology/landscape-ecology-the-basics-of-landscape-ecology/

[10]Fahrig L. 1992. Relative importance of spatial and temporal scales in a patchy environment. Theoretical Population Biology. Vol. 41 (3); 300-314.

[11]http://greenplanet.eolss.net