Merck
  • Home
  • Search Results
  • Does exogenous carbon extend the realized niche of canopy lichens? Evidence from sub-boreal forests in British Columbia.

Does exogenous carbon extend the realized niche of canopy lichens? Evidence from sub-boreal forests in British Columbia.

Ecology (2013-07-19)
Jocelyn Campbell, Per Bengtson, Arthur L Fredeen, Darwyn S Coxson, Cindy E Prescott
ABSTRACT

Foliose lichens with cyanobacterial bionts (bipartite and tripartite) form a distinct assemblage of epiphytes strongly associated with humid microclimatic conditions in inland British Columbia. Previous research showed that these cyano- and cephalolichen communities are disproportionately abundant and species-rich on conifer saplings beneath Populus compared to beneath other tree species. More revealing, lichens with cyanobacterial bionts were observed beneath Populus even in stands that did not otherwise support them. We experimentally test the hypothesis that this association is due to the interception of glucose-rich nectar that is exuded from Populus extra-floral nectaries (EFN). Using CO2 flux measurements and phospholipid fatty acid (PLFA) analysis with experimental applications of 13C6-labeled glucose, we demonstrate that cyano- and cephalolichens have a strong respiratory response to glucose. Lichens treated with glucose had lower net photosynthesis and higher establishment rates than control thalli. Furthermore, lichens with cyanobacterial bionts rapidly incorporate exogenous 13C into lichen fatty acid tissues. A large proportion of the 13C taken up by the lichens was incorporated into fungal biomarkers, suggesting that the mycobiont absorbed and assimilated the majority of applied 13C6 glucose. Our observations suggest that both cyanolichens and cephalolichens may utilize an exogenous source of glucose, made available by poplar EFNs. The exogenous C may enable these lichens to become established by providing a source of C for fungal respiration despite drought-induced inactivity of the cyanobacterial partner. As such, the mycobiont may adopt an alternative nutritional strategy, using available exogenous carbon to extend its realized niche.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
D-Glucose-12C6, 16O6, 99.9 atom % 16O, 99.9 atom % 12C
Supelco
D-(+)-Glucose, analytical standard
Sigma-Aldrich
D-(+)-Glucose, ACS reagent
Sigma-Aldrich
D-(+)-Glucose, BioXtra, ≥99.5% (GC)
Sigma-Aldrich
D-(+)-Glucose, suitable for mouse embryo cell culture, ≥99.5% (GC)
Sigma-Aldrich
D-(+)-Glucose, Hybri-Max, powder, BioReagent, suitable for hybridoma
Sigma-Aldrich
D-(+)-Glucose, ≥99.5% (GC)
Sigma-Aldrich
D-(+)-Glucose, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99.5%
Sigma-Aldrich
D-(+)-Glucose, BioUltra, anhydrous, ≥99.5% (sum of enantiomers, HPLC)
Sigma-Aldrich
D-(+)-Glucose, tested according to Ph. Eur.
Sigma-Aldrich
D-(+)-Glucose, AR, anhydrous
Sigma-Aldrich
Glucose stock solution, 1000 mg/dL
Supelco
Dextrose, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Dextrose, meets EP, BP, JP, USP testing specifications, anhydrous
Supelco
D-(+)-Glucose solution, 1 mg/mL in 0.1% benzoic acid, standard for enzymatic assay kits GAGO20, GAHK20, STA20, analytical standard
Sigma-Aldrich
D-(+)-Glucose solution, 100 g/L in H2O, sterile-filtered, BioXtra, suitable for cell culture
Sigma-Aldrich
L-(−)-Glucose, ≥99%
Sigma-Aldrich
D-(+)-Glucose solution, 45% in H2O, sterile-filtered, BioXtra, suitable for cell culture