What is full form/ meaning of 'r' and 'K' in r-selection species and K-selection species? Does this 'r' means "Random" and the 'K' means "constant"?


This article discusses the origin of the terms. They come directly from the equation used to describe population dynamics. As Canadianer mentioned the Wiki also covers it quite well.

"r" stands for "rate" {growth rate}, r strategists have a high r value and a low K value. They grow fast but most die.

"K" stands for Kapazitätsgrenzen which is german for capacity limit, now called carrying capacity, K strategists have a low r and a high K. They grow slow but more survive.

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  • $\begingroup$ @Canadianer Thanks for catching that I meant to reverse the terms and then forgot to go back and do it when I started trying to get an equation to import. $\endgroup$ – John Apr 24 '17 at 20:31
  • $\begingroup$ That should be Kapazitätsgrenze. "Grenze" is the German word for limit/border. $\endgroup$ – Dunois Jun 7 '19 at 10:48
  • $\begingroup$ Correctly answers my question, and accepted using green tick mark. $\endgroup$ – Always Confused Sep 4 '19 at 15:44

If you are looking for a mnemonic, because I too find these terms hard to remember, then I use the following.

r-strategy = focus is on reproducing as much as possible - then all the other traits, grow fast, die young, etc, tend to follow.

K-strategy = focus is on the Kapacity (Germanised spelling) of the environment, i.e. do not exceed the carrying capacity of the local environment for your species.

  • 2
    $\begingroup$ The question is about the origin of these terms. Your answer doesn't seem to address that. $\endgroup$ – WYSIWYG Jun 6 '19 at 8:19
  • $\begingroup$ Upvoted since it may indicate possible etymology but op wasnt finding mnemonic rather op was misleaded where somehow a mnemonic was misinterpreted as a techinical. definition. $\endgroup$ – Always Confused Sep 4 '19 at 15:42

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