Hamrick, J. L. and V. J. Apsit. 2004. Breeding structure of neotropical dry-forest tree species in fragmented landscapes. Pp. 30-37. In Frankie, G. W., A. Mata and S. B. Vinson (eds.). Biodiversity Conservation in Costa Rica: Learning the Lessons in a Seasonal Dry Forest. University of California Press, Berkeley, CA.

Trapnell, D. W., J. L. Hamrick and J. D. Nason. 2004. Three-dimensional fine-scale genetic structure of the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 13:1111-1118.

DeWalt, S. J., J. S. Denslow and J. L. Hamrick. 2004. Biomass allocation, growth, and photosynthesis of genotypes from native and introduced ranges of the tropical shrub Clidemia hirta. Oecologia 138:521-531.

Otero-Arnaiz, A., J. Cruse-Sanders, A. Casas and J. L. Hamrick. 2004. Isolation and characterization of microsatellites in the columnar cactus Polaskia chickipe and cross-species amplification within the Tribe Pachycereeae (Cactaceae). Mol. Ecol. Notes 4:265-267.

Cruse-Sanders, J. M. and J. L. Hamrick. 2004. Genetic diversity in harvested and protected populations of wild American ginseng, Panax quinquefolius L. (Araliaceae). Am. J. Bot. 91:540-548.

Trapnell, D. W., J. L. Hamrick and D. E. Giannasi. 2004. Genetic variation and species boundaries in Calopogon (Orchidaceae). Syst. Bot. 29:308-315.

Erickson, D. L., J. L. Hamrick and G. D. Kochert. 2004. Ecological determinants of genetic diversity in an expanding population of the shrub Myrcia cerifera. Mol. Ecol. 13:1655-1664.

Wang, Z. –F., J. L. Hamrick, and M. J. W. Godt. 2004. High genetic diversity in Sarracenia leucophylla (Sarraceniaceae), a carnivorous wetland herb. J. Heredity 95:234-243.

Godt, M J. W., J. Walker and J. L. Hamrick. 2004. Allozyme diversity in Macbridea alba (Lamiaceae), an endemic Florida mint. J. Heredity 95:244-249.

Hamrick, J. L. 2004. Response of forest trees to global environmental changes. For. Ecol. and Manag. 197:323-335.

Cruse-Sanders, J. M. and J. L. Hamrick. 2004. Spatial and genetic structure within populations of wild American ginseng (Panax quinquefolius L. Araliaceae). J. Heredity 95:309-321.

Dunphy, B. K., J. L. Hamrick and J. Schwagerl. 2004. A comparison of direct and indirect measures of gene flow in the bat-pollinated tree Hymenaea courbaril in the dry forest life zone of southwestern Puerto Rico. Int. J. Plant Sci. 165:427-436.

Trapnell, D. W. and J. L. Hamrick. 2004. Partioning nuclear and chloroplast variation at multiple spatial scales in the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 13:2655-2666.

DeWalt, S. J. and J. L. Hamrick. 2004. Genetic variation of introduced Hawaiian and native Costa Rican populations of an invasive tropical shrub, Clidemia hirta (Melastomataceae). Am. J. Bot. 91:1155-1162.

Stacy, E. A. and J. L. Hamrick. 2004. Using forest dynamics plots for studies of tree breeding structure: Examples from Barro Colorado Island. Pp 264-278. In Losos, E. C. and E. G. Leigh (eds.). Tropical forest diversity and dynamism. University of Chicago Press, Chicago.

Franks, S. J., C. L. Richards, E. Gonzales, J. E. Cousins and J. L. Hamrick. 2004. Multi-scale genetic analysis of Uniola paniculata (Poaceae): A coastal species with a linear, fragmented distribution. Am. J. Botany 91:1345-1351.

Richards, C. L., J. L. Hamrick, L. A. Donovan and R. Mauricio. 2004. Unexpectedly high clonal diversity of two salt marsh perennials across a severe environmental gradient. Ecol. Letters 7:1155-1162.

Grace, S. L., J. L. Hamrick and W. J. Platt. 2004. Estimation of seed dispersal in an old-growth population of longleaf pine (Pinus palustris) using maternity exclusion analysis. Castanea 69:207-215.

Godt, M. J. W., J. L. Hamrick and A. Meier. 2004. Genetic diversity in Cymophyllus fraserianus (Cyperaceae), a rare monotypic genus. Genetica 122:207-215.

Trapnell, D. W. and J. L. Hamrick. 2005. Mating patterns and gene flow in the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 14:75-84.

Cruse-Sanders, J. M., J. L. Hamrick and J. A. Ahumada. 2005. Consequences of harvesting for genetic diversity in American ginseng (Panax quinquefolius L.): a simulation study. Biodiversity and Conservation. 14:493-504.

Dunphy, B. K. and J. L. Hamrick. 2005. Gene flow among established Puerto Rican populations of the exotic tree species, Albizia lebbeck. Heredity 94: 418-425.

Otero-Arnaiz, A., A. Casas, J. L. Hamrick and J. Cruse-Sanders. 2005. Genetic variation and evolution of Polaskia chichipe (Cactaceae) under domestication in the Techuacan Valley, central Mexico. Mol. Ecol. 14:1603-1612.

Godt, M. J. W., F. Caplow and J. L. Hamrick. 2005. Allozyme diversity in the federally threatened golden paintbrush, Castilleja levisecta (Scrophulariaceae). Cons. Genet. 6:87-99.