- •Integrative levels, scope, and scale of organization
- •Hierarchical ecology
- •Biodiversity
- •Habitat
- •Niche construction
- •Biosphere
- •Population ecology
- •Metapopulations and migration
- •Community ecology
- •Ecosystem ecology
- •Food webs
- •Trophic levels
- •Keystone species
- •Ecological complexity
- •Relation to evolution
- •Behavioral ecology
- •Social ecology
- •Coevolution
- •Biogeography
- •Molecular ecology
- •Human ecology
- •Relation to the environment
- •Disturbance and resilience
- •Metabolism and the early atmosphere
- •Radiation: heat, temperature and light
- •Gravity
- •Pressure
- •Wind and turbulence
- •Biogeochemistry
- •After the turn of 20th century
After the turn of 20th century
Some suggest that the first ecological text (Natural History of Selborne) was published in 1789, by Gilbert White (1720–1793).[238] The first American ecology book was published in 1905 by Frederic Clements.[239] In his book, Clements forwarded the idea of plant communities as a superorganism. This publication launched a debate between ecological holism and individualism that lasted until the 1970s. The Clements superorganism concept proposed that ecosystems progress through regular and determined stages of seral development that are analogous to developmental stages of an organism whose parts function to maintain the integrity of the whole. The Clementsian paradigm was challenged by Henry Gleason.[240] According to Gleason, ecological communities develop from the unique and coincidental association of individual organisms. This perceptual shift placed the focus back onto the life histories of individual organisms and how this relates to the development of community associations.[241]
The Clementsian superorganism theory has not been completely rejected, but some suggest it was an overextended application of holism.[115] Holism remains a critical part of the theoretical foundation in contemporary ecological studies.[163] Holism was first introduced in 1926 by a polarizing historical figure, a South African General named Jan Christian Smuts. Smuts was inspired by Clement's superorganism theory as he developed and published on the concept of holism, which contrasts starkly against his racial political views as the father of apartheid.[242] Around the same time, Charles Elton pioneered the concept of food chains in his classical book "Animal Ecology".[86] Elton[86] defined ecological relations using concepts of food chains, food cycles, food size, and described numerical relations among different functional groups and their relative abundance. Elton's 'food cycle' was replaced by 'food web' in a subsequent ecological text.[243]
Ecology has developers in many nations, including Russia's Vladimir Vernadsky and his founding of the biosphere concept in the 1920s[244] or Japan's Kinji Imanishi and his concepts of harmony in nature and habitat segregation in the 1950s.[245] The scientific recognition or importance of contributions to ecology from other cultures is hampered by language and translation barriers.[