Complementary N Uptake Strategies between Tree Species in Tropical Rainforest
Résumé
textlessptextgreater Within tree communities, the differential use of soil N mineral resources, a key factor in ecosystem functioning, may reflect functional complementarity, a major mechanism that could explain species coexistence in tropical rainforests. textlessitalictextgreaterEperua falcatatextless/italictextgreater and textlessitalictextgreaterDicorynia guianensistextless/italictextgreater , two abundant species cooccurring in rainforests of French Guiana, were chosen as representative of two functional groups with complementary N uptake strategies (contrasting leaf textlessitalictextgreaterδtextless/italictextgreater textlesssuptextgreater15textless/suptextgreater N signatures related to the textlessitalictextgreaterδtextless/italictextgreater textlesssuptextgreater15textless/suptextgreater N of their soil N source, textlessmath id="M1"textgreater textlessmrowtextgreater textlessmsuptextgreater textlessmrowtextgreater textlessmrowtextgreater textlessmtexttextgreaterNOtextless/mtexttextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmn mathvariant="normal"textgreater3textless/mntextgreater textless/mrowtextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmotextgreater-textless/motextgreater textless/mrowtextgreater textless/msuptextgreater textless/mrowtextgreater textless/mathtextgreater or textlessmath id="M2"textgreater textlessmrowtextgreater textlessmsuptextgreater textlessmrowtextgreater textlessmrowtextgreater textlessmtexttextgreaterNHtextless/mtexttextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmn mathvariant="normal"textgreater4textless/mntextgreater textless/mrowtextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmotextgreater+textless/motextgreater textless/mrowtextgreater textless/msuptextgreater textless/mrowtextgreater textless/mathtextgreater ). The objectives were to investigate if these strategies occurred under contrasted soil N resources in sites with distinct geological substrates representative of the coastal rainforests. Results showed that species displayed contrasting leaf textlessitalictextgreaterδtextless/italictextgreater textlesssuptextgreater15textless/suptextgreater N signatures on both substrates, confirming their complementary N uptake strategy. Consequently, their leaf textlesssuptextgreater15textless/suptextgreater N can be used to trace the presence of inorganic N-forms in soils ( textlessmath id="M3"textgreater textlessmrowtextgreater textlessmsuptextgreater textlessmrowtextgreater textlessmrowtextgreater textlessmtexttextgreaterNHtextless/mtexttextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmn mathvariant="normal"textgreater4textless/mntextgreater textless/mrowtextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmotextgreater+textless/motextgreater textless/mrowtextgreater textless/msuptextgreater textless/mrowtextgreater textless/mathtextgreater and textlessmath id="M4"textgreater textlessmrowtextgreater textlessmsuptextgreater textlessmrowtextgreater textlessmrowtextgreater textlessmtexttextgreaterNOtextless/mtexttextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmn mathvariant="normal"textgreater3textless/mntextgreater textless/mrowtextgreater textless/mrowtextgreater textlessmrowtextgreater textlessmotextgreater-textless/motextgreater textless/mrowtextgreater textless/msuptextgreater textless/mrowtextgreater textless/mathtextgreater ) and thus to indicate the capacity of soils to provide each of these two N sources to the plant community. textless/ptextgreater
Auteurs, date et publication :
Auteurs J. C. Roggy , H. Schimann , D. Sabatier , J. F. Molino , V. Freycon , Anne-Marie Domenach
Publication : International Scholarly Research Notices
Date : 2014
Volume : 2014
Pages : 1–6