In:
Radiocarbon, Cambridge University Press (CUP), Vol. 60, No. 1 ( 2018-02), p. 269-281
Abstract:
Hemiparasitic plants obtain water and solutes from their hosts, but much remains to be learned about these transfers. We used a forest girdling experiment to investigate how leaf gas exchange, carbon and nitrogen cycling in the root hemiparasite Melampyrum lineare Desr. responded to disturbance and changes in physiology of potential host trees. By preventing belowground C allocation by 35% of the canopy, girdling decreased the starch and soluble sugar contents of bulk forest floor fine roots. Photosynthetic rates of M. lineare were statistically significantly lower in the girdled plot, but their hypothesized drivers (foliar N, stomatal conductance and transpiration) had no statistically significant differences between girdled and non-girdled plots. However, M. lineare in the girdled plot had higher foliar C concentrations and Δ 14 C than in the control plot, suggesting possible photosynthetic down-regulation in the girdled plot due to influx of older (e.g., host-derived) C into the leaves of M. lineare . Within the girdled plot (but not the control plot), M. lineare foliar C concentrations were positively correlated with foliar Δ 14 C and δ 15 N, suggesting that M. lineare may respond to changes in both C and N biogeochemistry during the decline of dominant canopy species.
Type of Medium:
Online Resource
ISSN:
0033-8222
,
1945-5755
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2018
detail.hit.zdb_id:
2028560-7
SSG:
11
SSG:
13
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