( ( ( where ( N ( is ( population size ) ) ) ) ( , ( r ( is ( growth rate ) ) ) ) ) ( , ( K ( ( is ( carrying capacity ) ) . ) ) ) )
(ROOT (S (S (SBAR (WHADVP (WRB where)) (S (NP (NNP N)) (VP (VBZ is) (NP (NN population) (NN size))))) (, ,) (NP (SYM r)) (VP (VBZ is) (NP (NN growth) (NN rate)))) (, ,) (NP (NNP K)) (VP (VBZ is) (VP (VBG carrying) (NP (NN capacity)))) (. .)))
where N is population size, r is growth rate, K is carrying capacity.
(ROOT (S (NP (NNP Growth)) (VP (VBZ stops) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (NN population)) (VP (VBZ reaches) (NP (DT the) (VBG carrying) (NN capacity)))))) (. .)))
Growth stops when a population reaches the carrying capacity.