One aspect of his research concerns the effects of climate change on biodiversity. He has contributed to papers on the impacts of climate change on plant evolution[3][4][5] as well as reviews of data source quality[6] and computational approaches to large-scale niche modelling.[7]
His work on the evolutionary biology of plants of interest to horticulture includes relationships within Pelargonium[8][9][10] (a collaboration with Mary Gibby of the Royal Botanic Garden Edinburgh), evolutionary patterns within plant genera on islands, with emphasis on Echium, the phylogenetic history of Drosera and phylogenetic and taxonomic revision on Actaea[11] and Ranunculaceae tribe Actaeae[12] (in collaboration with James Compton), a phylogenetic evaluation of Plectranthus and Solenostemon (coleus) (in collaboration with Alan Paton from the Royal Botanic Gardens, Kew) and recently a review of Cyclamen phylogeny and classification[13] (in collaboration with James Compton and The Cyclamen Society).
Culham is also engaged in research on the use of molecular markers for the study of genetic diversity within plant populations for the conservation of endangered species. This was applied in a project to determine the genetic diversity within Toromiro (Sophora toromiro),[14] an endemic plant of Easter Island (in collaboration with Mike Maunder[15]).
In fungi he has worked on development of molecular markers for identification of phytopathogenic soil fungi of the genus Fusarium[16][17] with colleagues Roland Fox and Prashant Mishra of the University of California.
As of 2012 he coordinates the i4Life project, having recently completed the project that built the Catalogue of Life.[18]
^Yesson, C. and Culham, A. (2006) Phyloclimatic modeling: Combining phylogenetics and bioclimatic modeling. Systematic Biology, 55 (5). pp. 785–802. ISSN 1063-5157 doi:10.1080/1063515060081570
^Heywood, V. and Culham, A. (2009) The impacts of climate change on plant species in Europe. Report T-PVS/Inf9E. In: Convention on the conservation of European wildlife and natural habitats. 29th meeting of the Standing Committee, Bern.
^Yesson, C., Toomey, N. H. and Culham, A. (2009) Cyclamen: time, sea and speciation biogeography using a temporally calibrated phylogeny. Journal of Biogeography, 36 (7). pp. 1234–1252. ISSN 0305-0270 doi:10.1111/j.1365-2699.2008.01971.x
^Yesson, C., Brewer, P. W., Sutton, T., Caithness, N., Pahwa, J. S., Burgess, M., Gray, W. A., White, R. J., Jones, A. C., Bisby, F. A. and Culham, A. (2007) How global is the global biodiversity information facility? PLoS ONE, 2 (11). p. 1124. ISSN 1932-6203 doi:10.1371/journal.pone.0001124
^Heap, M. J. and Culham, A. (2010) Automated pre-processing strategies for species occurrence data used in biodiversity modelling. Lecture Notes in Computer Science: Lecture Notes in Artificial Intelligence, Part I (6279). pp. 517–526. ISSN 0302-9743 doi:10.1007/978-3-642-15384-6
^Bakker, F. T., Culham, A., Pankhurst, C. E. and Gibby, M. (2000) Mitochondrial and chloroplast DNA-based phylogeny of Pelargonium (Geraniaceae). American Journal of Botany, 87 (5). pp. 727–734. ISSN 1537-2197
^Bakker, F.T., Culham, A., Hettiarachi, P. , Touloumenidou, T. and Gibby, M. (2004) Phylogeny of Pelargonium (Geraniaceae) based on DNA sequences from three genomes. Taxon, 53 (1). pp. 17–28. ISSN 0040-0262
^Bakker, F.T., Culham, A., Marais, E.M. and Gibby, M. (2005) Nested radiation in Cape Pelargonium. In: Bakker, F.T., Chatrou, L.W., Gravendeel, B. and Pelser, P.B. (eds.) Plant Species-Level Systematics: New Perspectives on Pattern & Process. Gantner Verlag, Rugell, Liechtenstein. ISBN9783906166391
^Compton JA, Culham A, Jury SL. 1998 Reclassification of Actaea to include Cimicifuga and Souliea (Ranunculaceae): phylogeny inferred from morphology, nrDNA ITS, and cpDNA trnL-F sequence variation. Taxon 47 (3): 593–634
^Compton, J.A. and Culham, A. Phylogeny and circumscription of tribe Actaeeae Ranunculaceae. Systematic Botany, 27 (3) July–September 2002, 502–511.
^Compton, J.A., Clennett, J.C.B. and Culham, A. (2004) Nomenclature in the dock. Overclassification leads to instability: a case study in the horticulturally important genus Cyclamen (Myrsinaceae). Botanical Journal of The Linnean Society, 146 (3). pp. 339–349. ISSN 0024-4074 doi:10.1111/j.1095-8339.2004.00322.x
^Maunder, M., Culham, A., Alden, B., Zizka, G., Orliac, C., Lobin, W., Bordeu, A., Ramirez, J.M. and Glissmann-Gough, S. Conservation of the toromiro tree: Case study in the management of a plant extinct in the wild. Conservation Biology, 14(5), 2000, 1341–1350.
^Mishra, P.K., Fox, R.T.V. and Culham, A. (2003) Development of a PCR-based assay for rapid and reliable identification of pathogenic Fusaria. FEMS Microbiology Letters, 218 (2). pp. 329–332. ISSN 0378-1097 doi:10.1111/j.1574-6968.2003.tb11537.x
^Mishra, P.K., Fox, R.T.V. and Culham, A. (2003) Inter-simple sequence repeat and aggressiveness analyses revealed high genetic diversity, recombination and long-range dispersal in Fusarium culmorum. Annals of Applied Biology, 143 (3). pp. 291–301. ISSN 0003-4746 doi:10.1111/j.1744-7348.2003.tb00297.x
^Heywood, V.H. , Brummit, R.K., Culham, A. and Seberg, O. (2007) Flowering plant families of the world. Kew Books (Europe) Firefly Books (North America). ISBN9781554072064