( However ( there ( ( ( are ( exotic ( plant species ) ) ) ( that ( you ( should ( ( ( avoid ( at ( all costs ) ) ) , ) ( as ( they ( ( ( ( are ( more invasive ) ) ( then others ) ) and ) ( may ( threaten ( nearby habitats ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB However)) (NP (EX there)) (VP (VBP are) (NP (JJ exotic) (NN plant) (NNS species)) (SBAR (IN that) (S (NP (PRP you)) (VP (MD should) (VP (VB avoid) (PP (IN at) (NP (DT all) (NNS costs))) (, ,) (SBAR (IN as) (S (NP (PRP they)) (VP (VP (VBP are) (ADJP (RBR more) (JJ invasive)) (PP (RB then) (NP (NNS others)))) (CC and) (VP (MD may) (VP (VB threaten) (NP (JJ nearby) (NNS habitats)))))))))))) (. .)))
However there are exotic plant species that you should avoid at all costs, as they are more invasive then others and may threaten nearby habitats.
(ROOT (S (NP (JJ Exotic) (NNS species)) (VP (VBP are) (ADVP (RB also)) (VP (VBN called) (NP (JJ invasive) (NNS species)) (SBAR (IN because) (S (NP (PRP they)) (VP (VBP threaten) (NP (JJ other) (NNS species))))))) (. .)))