ECOLOGY

By Pedro L. Lomas

Concept

Etymologically, the name ‘ecology’ comes from the Greek words oikos (οἶκος) = house or home (in a broad sense) and logos (λóγος), that can be translated as study, thought, reflection, reason, etc. Thus, it means the reflection on or study of the home, which is how we conceive the Earth and nature. Ecology is usually spoken of as the science that studies the relationships between living beings and their surroundings, as it was originally defined by the German naturalist and philosopher Ernst Haeckel in 1866 (Haeckel, 1866).

Origin

Ecology is a relatively young science, in contrast with other fields of study, although its roots can be traced back to Antiquity in many cultures, since humans have always sought to learn about their environment and manage it adequately to obtain the necessary resources. It has also been known, sometimes, as ‘the economics of life’.

Modern ecology arose from observations conducted in the 18th and 19th centuries by European naturalists (Humboldt, Haeckel, Hutton, Lamarck, etc.) on their major expeditions across the five continents. In this period, as opposed to the particularism in field observations at concrete locations, researchers were able to gain a broader view of the living beings inhabiting the planet and the many different environments it harboured, and to identify the world’s major organisational and functional patterns, going beyond the scope of Botany and Zoology.

Thus emerged the concept of ecosystem, which Arthur Tansley formalised in the 1930s as the system formed by living elements, their inter-relations and their relationships with their environment (Tansley, 1935). Ecosystems are complex systems that emerge (the whole is greater than the sum of its parts) from the interaction between living beings and their environment (structure), that produce to the circulation of materials and energy, on a more or less homogeneous scale of component units, depending on the biogeophysical conditions (Odum, 1969).

Two other terms that are often confused with ecosystem, also studied in ecology, are the population or group of individuals of a single species inhabiting a given place at a given time, and the biological community, which refers to the set of organisms of diverse species co-existing in a given place at a given time. In both cases, the focus is on living beings, whereas in ecosystems, the reasoning centres on the system of living beings together with their surrounding environment. The whole of the planet’s ecosystems are known as the Biosphere or Ecosphere.

Classification

In the past, we find the terms autoecology and synecology, used to define, respectively, the study of organisms in relation to the environmental factors affecting them (often concomitantly with physiology, in what we might call ecophysiology), and the study of communities of organisms (often concomitantly with certain concepts such as taxon, association, community, etc., taken from Zoology and Botany).

However, given the nature of its object, this science has strong interdisciplinary roots, leading to myriad different ways in which to divide ecology. Some of the most outstanding are mentioned below.

According to the types of living beings studied: Animal ecology, plant ecology, microbial ecology, etc.
According to the type of ecosystem studied: Land ecology, aquatic ecology, marine ecology, limnology, etc.
According to the level of organisation: population ecology, community ecology, ecosystem ecology, landscape ecology, regional ecology, etc.
According to the geographical or climatic area analysed: Arctic ecology, tropical ecology, ecology of arid zones, etc.
According to the phenomenon studied: Ecophysiology, ecotoxicology, soil ecology, fire ecology, etc.

Besides, human beings, given the role they play in ecosystems, interact with the social sciences establishing hybrid fields of study, such as ecological economics, human ecology, socioecology, political ecology, environmental history, ecological humanities, etc., that study the mutual influence between humans and nature, from different angles.

Research object

The study of ecology covers a wide range of objects. Taking, for instance, the level of organisation as a division criterion, then we have the following:

Population ecology: this examines population size, dynamics, intra-specific relations and spatial distribution.
Community ecology: this examines community structure (wealth, relative abundance of species, biodiversity, spatial structure, etc.), interspecific relations, and community or ecological succession dynamics.
System ecology: this studies the structure of ecosystems, their functioning (food networks, and the circulation of nutrients and energy within and among these on different scales, including major biogeochemical cycles) and their dynamics or regulation.
Landscape ecology: this examines the interactions among different ecosystems.
Regional ecology: this studies the regionalisation of ecosystems according to their defining biogeophysical factors on each scale, up to the largest scale or biome (depending on climate).

Moreover, it was not until the 1960s and 70s that the idea of humans forming part of ecosystems and, hence, as an object of study within ecology began to take hold (Odum, 1953; Odum, 1971; Odum, 1975). Furthermore, despite some criticism, a number of authors sustain that, in view of human beings’ influence on the biosphere, we cannot speak of ecosystems as natural systems free from human influence, but should refer to social-ecological systems (Berkes & Folke, 1998), as human-nature co-evolution systems.

Methodology and method

The research conducted in ecology, as an interdisciplinary science connecting life sciences and Earth sciences, is based on a wide range of methodologies including those mentioned below.

Experimental or field ecology: the study of populations and communities through a multitude of census and sampling methods or, more recently, satellite data or aerial photography.
Quantitative ecology: the analysis of results from information gathered via a wide range of deterministic techniques and stochastic models, or through different forms of applied statistics and hypothesis testing.
Theoretical ecology: the study of ecosystems through diverse mathematical, statistical and modelling techniques.

Besides, introducing the human being as object of study has led to embracing other qualitative or semi-quantitative methods from other branches of knowledge.

Conceptual distinctions

Ecology-ecologism. In general terms, the distinction between ecology and ecologism is that ecology is a science while ecologism (sometimes referred to as environmentalism) is a social movement with many cultural ramifications, whose aim is to protect nature for a variety of reasons, such as the fact that human beings belong to nature, the fraternity among living beings, etc.

Ecology-environment. It is also common to confuse ecology with environment. While ecology is the science dealt with here, environment refers to the biogeochemical aspects (geophysical conditions and other living beings) that living beings, including human beings, interact with. It is often used as a synonym for nature or ecosystems.

Bibliography:

Berkes, F. & Folke, C. (Eds.). (1998). Linking Social and Ecological Systems: Management Practices and Social Mechanisms for Building Resilience. Cambridge University Press.

Haeckel, E. (1866). Generelle Morphologie der Organismen [La Morfología General de los Organismos]. (Vol. 2). Georg Reimer. https://www.biodiversitylibrary.org/page/15099032

Odum, E. P. (1953). Fundamentals of Ecology, W.B. Saunders Company.

Odum, E. P. (1969). The strategy of ecosystem development. Science, 164 (3877), 262-270.

Odum, E. P. (1975). Ecology: the link between the natural and the social sciences. (2^nd ed.) Holt, Rinehart and Winston.

Odum, H. T. (1971). Environment, Power and Society. John Wiley & Sons. https://archive.org/details/environmentpower00odum

Tansley, A. G. (1935). The use and abuse of vegetational concepts and terms. Ecology, 16 (3), 284-307.

Share content