In the twentieth century, Andrewartha became the most influential Australian ecologist, and best known for attributing density-independent forces, such as weather, to be even more important than density-dependent factors in influencing population regulation.
12.
If the population falls ( due to a bad winter or illegal harvest ) this will ease density-dependent population regulation and increase yield, moving the population back to N _ b, a stable equilibrium.
13.
Ecological concepts such as food chains, population regulation, and productivity were first developed in the 1700s, through the published works of microscopist Antoni van Leeuwenhoek ( 1632 1723 ) and botanist Richard Bradley ( 1688 ? 1732 ).
