- Application of Stable Isotope techniques on dietary ecology, soil geochemistry, paleolimnology, and forensics
- Application of GIS and Remote Sensing in modeling stable isotopes trends and patterns in plants, soils, and mammalian tissues,
- Systematic biology (Phylogenetics).
- Saturday, A., Makokha, G. M., Macharia, A. N. (2016). Household Water Treatment Technologies for Microbial Removal in Kabale District, Southwestern Uganda.Journal of Environment and Health Sciences, 2(1): 1–8.
- Macharia, A. N., Cerling, T. E., Matthew J. J., Jay R. K. (April 2014). The hair-diet 13C and 15N fractionation inChlorocebus aethiops sabaeus based on a control diet study. Ann. Zool. Fennici 51: 00–00 ISSN 0003-455X, (print), ISSN 1797-2450 (online). Helsinki 2014 © Finnish Zoological and Botanical Publishing Board
- Morris, J. L., le Roux, P. C., Macharia A. N., Brunelle, A., Hebertson, E. G., Lundeen, Z. J. (2013). Organic, elemental, and geochemical contributions to lake sediment deposits during severe spruce beetle, (Dendroctonus rufipennis) disturbances. Forest Ecology and Management, 289, 78–89.
- Macharia, A. N., Uno, K. T., Cerling, T. E., Brown, F. H. (2012). Isotopically distinct modern carbonates in abandoned livestock corrals in northern Kenya, Journal of Archaeological Science, 39: 2198–2205, doi:10.1016/j.jas.2012.02.005.
- Cerling, T. E., Andaje, S. A., Bird, M. I., Korir, D. K., Levin, N. E., Mace, W., Macharia, A. N., Remein, C. H., Wynn, J. G. (2011). Woody cover and hominin environments in the past 6 million years. Nature, 476: 51–56, doi:10.1038/nature10306.
- Macharia, A. N. (2016) Potential Benefits of Using Teaching Kits in Inquiry-Based Learning in Geosciences. Status Conference On Higher Education Conference,Kenyatta University, 22nd – 25th, 2016.
- Macharia, A. N. (2016) Modeling Stable Isotope Attributes of Wildlife Habitats Using Space Technologies for Forensics Applications. United Nations/Kenya Conference on Space Technology and Applications for Wildlife Management and Protecting Biodiversity. UNEP, Nairobi, 27th – 30th June, 2016
- Macharia, A. N., Cerling TE, Remien CH, Mace WD, Andanje SA, & Dennison PE (2014) Soil Carbon Isotope Ratios and Landscape Variability in East Africa. Africa Nazarene University 1st Annual International Conference: Information and communication technologies for sustainable development, 28th – 30th May, Ongata Rongai campus
- Macharia, A. N., Power, M. J. (2011) Long-term perspectives of Utah Lake. 25th October, 7th Annual Utah Lake Symposium, Utah Valley University.
- Macharia, A. N., Power, M. J. (2011) Deciphering the role of Climate- versus human-caused disturbance during the 19th and 20th century; A contrast between Utah Lake and Foy Lake. 6th to 9th March.Poster, Climate Variability of Eastern US and Western North Pacific (PACLIM) meeting, Pacific Grove, California.
- Cerling, T. E., Andanje, S., Kimutai, D., Levin, N. E., Mace, W. D., Macharia, A. N., Passey, B. H., Remien, C., Wynn, J. G. (2010) Paleo-shade: woody cover, stable isotopes, soil temperature, and soil organic matter in tropical ecosystems (Invited) American Geophysical Union, Fall Meeting, 13-14th December, Moscone Convention Center, San Francisco, California, USA
- Macharia, A. N., Power, M. J. (2010) Climatic, and anthropogenic influences on lake nutrient dynamics: An insight from 15N natural abundance of Utah Lake and Foy Lake sedimentary profiles. Poster, 55th Annual Meeting, American Association of Geographers, Washington DC, April 14–18.
- Macharia, A. N., Power, M. J. (2009) Climatic, and anthropogenic influences on lake nutrient dynamics: A contrast between Utah Lake and Foy Lake sedimentary profiles. Poster, American Association of Geographers, Great Plains, Rocky Mountain Division, September 25-26, Utah State University, Logan, Utah.