Degradation of mangrove tissues by arboreal termites (Nasutitermes acajutlae) and their role in the mangrove C cycle (Puerto Rico): Chemical characterization and organic matter provenance using bulk δ¹³C, C/N, alkaline CuO oxidation‐GC/MS, and solid‐state ¹³C NMR

Authors

Christopher H. Vane
Alexander W. Kim
Vicky Moss-Hayes
Collin E. Snape
Miguel Castro Diaz
Nicole S. Khan
Simon E. Engelhart, University of Rhode IslandFollow
Benjamin P. Horton

Document Type

Article

Date of Original Version

2013

Abstract

Arboreal termites are wood decaying organisms that play an important role in the first stages of C cycling in mangrove systems. The chemical composition of Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa leaf, stem, and pneumatophore tissues as well as associated sediments was compared to that of nests of the termite Nasutitermes acajutlae. Nests gave δ¹³C values of −26.1 to −27.2‰ (±0.1) and C/N of 43.3 (±2.0) to 98.6 (±16.2) which were similar to all stem and pneumatophores but distinct from mangrove leaves or sediments. Organic matter processed by termites yielded lignin phenol concentrations (Λ, lambda) that were 2–4 times higher than stem or pneumatophores and 10–20 times higher than that of leaves or sediments, suggesting that the nests were more resistant to biodegradation than the mangrove vegetation source. ¹³C NMR revealed that polysaccharide content of mangrove tissues (50–69% C) was higher than that of the nests (46–51% C). Conversely, lignin accounted for 16.2–19.6% C of nest material, a threefold increase relative to living mangrove tissues; a similar increase in aromatic methoxyl content was also observed in the nests. Lipids (aliphatic and paraffinic moieties) were also important but rather variable chemical components of all three mangrove species, representing between 13.5 and 28.3% of the C content. Termite nests contained 3.14 Mg C ha⁻¹ which represents approximately 2% of above ground C storage in mangroves, a value that is likely to increase upon burial due to their refractory chemical composition.

Citation/Publisher Attribution

Vane, C. H., A. W. Kim, V. Moss‐Hayes, C. E. Snape, M. C. Diaz, N. S. Khan, S. E. Engelhart, and B. P. Horton (2013), Degradation of mangrove tissues by arboreal termites (Nasutitermes acajutlae) and their role in the mangrove C cycle (Puerto Rico): Chemical characterization and organic matter provenance using bulk δ¹³C, C/N, alkaline CuO oxidation‐GC/MS, and solid‐state ¹³C NMR, Geochem. Geophys. Geosyst., 14, 3176–3191, doi: 10.1002/ggge.20194.

Available at: https://doi.org/10.1002/ggge.20194

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.