2.2 Developing a historic understanding of ecology and ecosystems
The term “ecology” is derived from the ancient Greek oikos, meaning “house” or “environment.” The field of ecology, as a specified domain or discipline of academic research, was defined in 1906 by Ernest Hackel, a German biologist, naturalist, and artist. He used the term “ecology” to label the rigorous science that seeks to comprehend the relations of organism to their surrounding environment, which includes “all conditions for existence” (quoted in Schulze et al. 2002, p. 1). As this meaning indicates, living organisms—even semi‐living entities like viruses, and certainly all plants and animals, including humans—cannot live without resources provided by the physical world immediately around them. The deeper roots of ecological study trace back to the natural history observations of revered ancient Greek philosophers like Herodotus, Aristotle, and Hippocrates, and even further back to the need of all indigenous people to know their environment, as life itself depended upon it.
2.2.1 Ancient Greece
Some of the earliest Western conceptions of the environment, such as ideas about nature being characterized by balance and internal regulation, have been attributed to Herodotus, though the word “ecology” does not appear in ancient Greek philosophical literature. Nonetheless, Herodotus provided one of the earliest written accounts of the relationship of mutualism, based on his observation of the way basking Nile crocodiles would open their mouths to give sandpipers safe access to remove leeches, which provided food for the birds and oral hygiene for the crocodiles (noted in Egerton 2001). Aristotle was an early influence on the philosophical development of ecology. He had a lifelong fascination with nature studies, and with his student Theophrastus, he carried out extensive observations on plant and animal migration, biogeography, physiology, and behavior (Hughes 1975, 1985).
Theophrastus had a long and productive life as a botanist, living to the age of 85. Following Aristotle’s death, he succeeded him as a director of the Lyceum in Athens, a position he held for 35 years. Founded by Aristotle, the Lyceum was called the Peripatetic School (from the Greek peripatos, “stroll”), apparently after Aristotle’s habit of meandering through its tree‐filled groves discussing philosophy, mathematics, and rhetoric with his eager students. The Lyceum embraced an organized and rigorous approach to the study of nature and is considered by some to have pointed the direction for the modern scientific method. Theophrastus arrived there at the young age of 17 and became a dedicated student and disciple of both Aristotle and his approach. Considered “the father of botany,” he conducted experiments and made and recorded observations on plant propagation, classification, physiology, and behavior. Unlike his teacher, however, he believed that animals could reason and therefore concluded that it was unethical to eat meat. Thus, he became a vegetarian and devoted his life to the study of vegetation.
As Hughes (1975) indicates, an underlying view of nature at the Lyceum, which became particularly pronounced in Theophrastus’ writings on plants, was an understanding of the physical world “as the theatre of reason,” a view “which made the beginnings of ecological thought possible.” In his various writings, especially De Historia Plantarum (The History of Plants) and the first five books of De Causis Plantarum (The Causes of Plants), Theophrastus (Long et al. 1985) describes plants as having three aspects. The first is their inner nature, which modern scientists trained in genetics would call their genotype, but he called telos, which means purpose or goal. The second aspect is their environment, including soil, moisture, temperature, exposure to the elements, wind, and elevation. Theophrastus believed the environment might support or act against a plant’s inner nature. Unlike later writers on the nature of nature, Theophrastus did not prescribe environmental determinism, but instead held an interactionist understanding of the distinctive features of plants and the distinctive features of their environments. Plants, he recognized, were adapted to local conditions, or what he called “mutation according to place.” Consequently, he believed plants must be studied in their normal setting, in what modern ecologists would call their natural ecosystem. Part of the environment of a plant, Theophrastus realized, was other plants. He noted that olive and myrtle trees, like pine and bay trees, tended to grow together, and he observed that close‐dwelling species might either compete with or benefit each other. Legumes, he understood, enrich the soil with nutrients absorbed by other plants. Ivy, however, kills the trees it grows on (Fig. 2.1). Moreover, aware of Aristotle’s discussion of interspecies cooperation, he noted examples of birds contributing to the welfare of plants. Jays, for example, bury acorns, some of which sprout to grow new oak trees, which support jay populations. Thus, he was aware of the features of ecology now known as symbiosis and parasitism.
Fig. 2.1 Ivy growing on a tree.
Source: Free‐Photos/Pixabay.
Theophrastus’ final aspect of plants, one critical to the issues addressed in this book, is human agency, “which may have a goal quite at variance with both the plant and the environment” (Hughes 1985, p. 296). Unlike Aristotle, Theophrastus did not think plants existed to serve humans. In his Metaphysics, he asserted that:
We must try to find a certain limit … both to final causation and to the impulse to the better. For this is the beginning of the inquiry about the universe, that is, of the effort to determine the conditions on which real things depend and the relations in which they stand to one another.
(Ross & Forbes 1967, p. 92)
Moreover, he argued that the purpose of a plant has nothing to do with humans, but rather is just what plants will do without human agency: grow and reproduce.
Interestingly, Theophrastus realized that humans could have an impact, through acts like drainage, on regional climate. He stated that:
The country around Larisa in Thessaly [in ancient and modern Greece], where formally, when there was much standing water and the plain was a lake, the air was thicker and the country warmer; but now that the water has been drained away and prevented from collecting, the country has become colder and freeing more common. In proof the fact is cited that formally there were fine tall olive trees in the city itself and elsewhere in the country, whereas now they are found nowhere, and the vine were never frozen before but freeze now often.
(quoted in Hughes 1985, p. 303)
Further, he documented that deforestation could influence climate, noting that on the island of Crete, once heavily forested, extensive commercial logging and timber export had enhanced the severity of the wind, to the point that agriculture became unsustainable for many years. In Philippi, a city in eastern Macedonia, he asserted that the combined effects of drainage and deforestation—a case of ecocrises interaction—moderated the climate by allowing wind to blow away freezing air. These observations indicate that human awareness of anthropogenic climate change is over 5000 years old. In Hughes’ (1985, pp. 304–305) view:
If [Theophrastus] failed as a consistent ecologist, it was in concentrating his attention on individual species. Unlike modern ecologists, he did not emphasize the complex net of relationships in biotic communities … But it is hard to criticize him too severely, because he was the first to set out