( ( At ( its ( simplest level ) ) ) ( , ( biodiversity ( ( measures ( ( the ( ( numbers and ) variety ) ) ( of ( species ( in ( an ecosystem ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN At) (NP (PRP$ its) (JJS simplest) (NN level))) (, ,) (NP (NN biodiversity)) (VP (VBZ measures) (NP (NP (DT the) (NNS numbers) (CC and) (NN variety)) (PP (IN of) (NP (NP (NNS species)) (PP (IN in) (NP (DT an) (NN ecosystem))))))) (. .)))
At its simplest level, biodiversity measures the numbers and variety of species in an ecosystem.
(ROOT (S (NP (NNP Biodiversity)) (VP (VBZ is) (NP (NP (DT a) (NN measurement)) (PP (IN of) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN variation)) (PP (IN of) (NP (NP (DT the) (NN species)) (PP (IN in) (NP (DT a) (VBN given) (NN area))))))))))) (. .)))