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Carbon and nitrogen parasitism by a xylem‐tapping mistletoe ( Tapinanthus oleifolius ) along the Kalahari Transect: a stable isotope study
Author(s) -
Wang Lixin,
Kgope Barney,
D’Odorico Paolo,
Macko Stephen A.
Publication year - 2008
Publication title -
african journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.499
H-Index - 54
eISSN - 1365-2028
pISSN - 0141-6707
DOI - 10.1111/j.1365-2028.2007.00895.x
Subject(s) - transect , xylem , botany , nitrogen , isotopes of carbon , biology , nutrient , isotopes of nitrogen , parasitism , stable isotope ratio , host (biology) , ecology , chemistry , total organic carbon , organic chemistry , quantum mechanics , physics
The present study explores the xylem‐tapping parasitism by mistletoe ( Tapinanthus oleifolius ) on native tree species along the Kalahari Transect (KT) using the stable isotopes of carbon and nitrogen. Mistletoe‐host pairs were collected at three geographical locations along the KT rainfall gradient in the 2005 and 2006 wet seasons. Foliar total carbon, total nitrogen and their stable isotope compositions (δ 13 C and δ 15 N) were measured. Heterotrophy ( H ) was calculated using foliar δ 13 C values of mistletoes and their hosts as an indicator of proportion of carbon in the mistletoes derived from host photosynthate. Based on the mistletoe H ‐value and relationship between the mistletoe foliar δ 15 N and their host foliar δ 15 N, the results showed that mistletoes along the KT derived both nitrogen and carbon from their hosts. Mistletoes may regulate water use in relation to nitrogen supply. The proportion of carbon in the mistletoes derived from host photosynthate was between 35% and 78%, and the degree of heterotrophy was species‐specific with only limited annual variation. The study emphasizes the importance of incorporating parasitic associations in future studies on studying carbon, water and nutrient cycling along the Kalahari.