( ( Biogeographic provinces ) ( ( could ( ( ( be ( ( the basis ) ( for ( ( a ( primary choice ) ) ( of ( sampling strata ) ) ) ) ) ) , ) ( although ( these ( ( ( are not ) ( absolute ( in character ) ) ) ( because ( phytoplankton ( are ( ( ( ( ( ( affected ( by ( ( climate and ) latitude ) ) ) , ) ( zooplankton ( by ( ocean ( ( circulation and ) fronts ) ) ) ) ) , ) and ) ( benthos ( by ( ( depth and ) ( ( the nature ) ( of ( the ( sea floor ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Biogeographic) (NNS provinces)) (VP (MD could) (VP (VB be) (NP (NP (DT the) (NN basis)) (PP (IN for) (NP (NP (DT a) (JJ primary) (NN choice)) (PP (IN of) (NP (JJ sampling) (NN strata)))))) (, ,) (SBAR (IN although) (S (NP (DT these)) (VP (VBP are) (RB not) (ADJP (JJ absolute) (PP (IN in) (NP (NN character)))) (SBAR (IN because) (S (NP (NN phytoplankton)) (VP (VBP are) (VP (VP (VBN affected) (PP (IN by) (NP (NN climate) (CC and) (NN latitude)))) (, ,) (VP (VBN zooplankton) (PP (IN by) (NP (NN ocean) (NN circulation) (CC and) (NNS fronts)))) (, ,) (CC and) (VP (VBZ benthos) (PP (IN by) (NP (NP (NN depth)) (CC and) (NP (NP (DT the) (NN nature)) (PP (IN of) (NP (DT the) (NN sea) (NN floor)))))))))))))))) (. .)))
Biogeographic provinces could be the basis for a primary choice of sampling strata, although these are not absolute in character because phytoplankton are affected by climate and latitude, zooplankton by ocean circulation and fronts, and benthos by depth and the nature of the sea floor.
(ROOT (S (NP (NP (VBG Living) (NNS things)) (PP (IN on) (NP (DT the) (NN ocean) (NN floor)))) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NNS benthos))))) (. .)))
Living things on the ocean floor are known as benthos.