The Ten Principles of Ecology
1. Evolution organizes ecological systems into hierarchies.
Individual organisms combine into populations, populations combine into species, species combine into higher taxa like genera and phyla. Each can be characterized by its abundance and diversity (number of kinds) in a given ecosystem or study plot. How and why abundance and diversity vary in time and space is the basic question of ecology.
2. The sun is the ultimate source of energy for most ecosystems.
Life runs on the carbon-rich sugars produced by photosynthesis; every ecosystem’s sugar output depends on how much solar energy and precipitation it receives.
3. Organisms are chemical machines that run on energy.
The laws of chemistry and physics limit the ways each organism makes a living and provide a basic framework for ecology. The supply of chemical elements and the sugars needed to fuel their assembly into organisms limit the abundance and diversity of life.
4. Chemical nutrients cycle repeatedly while energy flows through an ecosystem.
The atoms of elements like C, N, P, and Na go back and forth from spending time in living to spending time in dead parts of an ecosystem. But the photons of solar energy can be used only once before they are lost to the universe.
The rate that a population’s abundance in a given area increases or decreases reflects the balance of its births, deaths, and net migration into the area. Individuals with features that improve their ability to survive (i.e., not die) and make copies of themselves will tend to increase in that population.
The rate that the diversity of species in an area changes reflects the balance of the number of new forms that arise, those that go extinct, and those that migrate into the area. Individuals and species that have features allowing them to survive and reproduce in a local environment will tend to persist there.
7. Organisms interact—do things to each other—in ways that influence their abundance.
Individual organisms can eat one another, compete for shared resources, and help each other survive. Each pair of species in an ecosystem can be characterized by the kind and strength of these interactions, measured as their contribution to dN/dt.
8. Ecosystems are organized into webs of interactions.
The abundance of a population is influenced by the chains of interactions that connect it to the other species in its ecosystem. This often leads to complex behavior, and a key challenge in ecology is to determine what patterns of abundance and diversity can be predicted.
9. Human populations have an outsized role in competing with, preying upon, and helping other organisms.
Humans are one of millions of species embedded in Earth’s ecosystems. The ability of humans to change the planet, abetted by our large population size and technological prowess, increases our ability to shape the biosphere’s future. Humans, through principles 1-8, are currently changing the climate, re-arranging its chemistry, decreasing populations of food, moving around its species, and decreasing its diversity.
10. Ecosystems provide essential services to human populations.
These include products like timber, fiber and food, regulating water and air quality, and cultural benefits like recreation. A key goal of ecology is to use principles 1-9 to preserve ecosystem services.
Interesting stuff. A nice, concise statement — but depending on a huge, broad, deep, expansive knowledge and understanding of biology, physics, chemistry, geology, history, meteorology, mathematics, and more.