Diversity and adaptation are the two great cosmological concerns of biology, and abiding themes of my own research. I explore several questions at the interface of ecology, evolution, systematics and biogeography: • What are the historical processes by which plant species arise, diverge ecologically, and come to occupy different habitats and geographic regions? • How do various features of plant form, physiology, and behavior affect energy capture and growth under different conditions, and thereby result in competitive success in some contexts and not others? • How can adaptations constrain species distributions and help create gradients in the composition, structure, and diversity of communities and landscapes? • What are the roles of spatially coupled, positive and negative feedbacks in creating patterned landscapes, and how might these be important in designing conservation and restoration strategies at large spatial scales? Research by my students, colleagues, and I involves a wide range of terrestrial, wetland, and aquatic systems, from boreal forests, ponds, and peatlands to cloud forests and bogs in Hawaii, prairies and savannas in the Midwest, rich temperate forests in the southern Appalachians, marshes, sloughs, and tree islands in the Florida Everglades, sclerophyll woodlands and temperate rain forests in western North America and Australia, rain forests in Central America, and cloud forests and bogs atop the tepuis of the ancient Guayana Shield in South America. Current projects focus on the following topics: 8BUPvaP<[
Recent Publications Givnish TJ, Millam KC., Evans TM, Hall JC, Pires JC, Berry PE, Sytsma KJ. 2004 Ancient vicariance or recent long-distance dispersal? Inferences about phylogeny and South American-African disjunctions in Rapateaceae and Bromeliaceae based on ndhF sequence data. Intern J Plant Sci (in press). Givnish TJ, Montgomery RA, Goldstein G. 2004 Adaptive radiation of photosynthetic physiology in the Hawaiian lobeliads: light regimes, static light responses, and whole-plant compensation points. Am J Bot 91: 228-246. pdf Patterson TB, Givnish TJ. 2004 Geographic cohesion, chromosomal evolution, parallel adaptive radiations, and consequent floral adaptations in Calochortus (Liliaceae): evidence from a cpDNA sequence phylogeny. New Phytol 161: 253-264. pdf Givnish TJ. 2003 How a better understanding of adaptations can yield better use of morphology in plant systematics: towards eco-evo-devo. Taxon 53:273-296. pdf Evans TM, Sytsma KJ, Faden RB, Givnish TJ. 2003 Phylogenetic relationships in the Commelinaceae: II. A cladistic analysis of rbcL sequences and morphology. Syst Bot 28: 270-292. pdf Patterson TB, Givnish TJ. 2002 Phylogeny, concerted convergence, and phylogenetic niche conservatism in the core Liliales: insights from rbcL and ndhF sequence data. Evol 56:233-252. pdf Givnish TJ. 2002 On the adaptive significance of evergreen vs. deciduous leaves: solving the triple paradox. Silva Fennica 36: 703-743. pdf Mäkela A, Givnish TJ, Berninger F, Buckley TN, Farquhar GD, Hari P. 2002 Challenges and opportunities of the optimality approach in plant ecology. Silva Fennica 36:605-614. pdf Mast AR, Givnish TJ. 2002 Historical biogeography and the origin of stomatal protection in Banksia and Dryandra (Proteaceae) based on their cpDNA phylogeny. Am J Bot 89:1311-1323. pdf Givnish TJ. 2001 The rise and fall of plant species: a population biologist's perspective. Am J Bot 88:1928-1934. pdf Givnish TJ, Evans TM, Zjhra ML, Patterson TB, Berry PE, Sytsma KJ. 2000 Molecular evolution, adaptive radiation, and geographic diversification in the amphiatlantic family Rapateaceae: evidence from ndhF sequences and morphology. Evol 54:1915-1937. pdf Chase MW, Soltis DE, Soltis PS, Rudall PJ, Fay MF, Hahn WH, Sullivan S, Joseph J, Givnish TJ, Sytsma KJ, Pires JC 2000. Higher-level systematics of the monocotyledons: an assessment of current knowledge and a new classification. Pp. 3-16 in KL Wilson, DA Morrison, eds. Monocots: systematics and evol-ution. CSIRO Publishing, Collingwood, Australia. Givnish TJ 1999. On the causes of gradients in tropical tree diversity. J Ecol 87:193-210. pdf Leach MK, Givnish TJ. 1999 Gradients in the composition, structure, and diversity of remnant oak savannas in southern Wisconsin. Ecol Monogr 69:353-374. pdf 32[ lsU>1
Copyright notice: PDF's are provided to provide timely dissemination of scholarly research. Copyrights are retained by the authors and/or publishers. Anyone downloading the pdfs is expected to obey the legal requirements imposed by copyright law, and may not repost these documents without explicit permission from the copyright holder. Photographs: TOP - Portrait of the scientist as a young man among Nymphaea tuberosa; Platanthera leucophaea (Orchidaceae), one of the most rapidly disappearing species in Midwestern wet prairies; species-rich Eucalyptus woodland, Stirling Range; profile of the Great Smoky Mountains in early spring. BOTTOM - Floral diversity in Rapateaceae; sandstone escarpment, Auyán-tepui, one of the many sandstone plateaus of the ancient Guayana Shield and home to many narrow endemics; Cyanea floribunda, a highly shade-adapted lobeliad, in the Ola`a Tract of Hawaii Volcanoes National Park; false-color satellite image of the central and southern Everglades, showing patterned landscape with streamlined tree islands and a series of water-control structures constructed over the last half-century. |
