Assistant Professor (until March 2013)
Ecosystem Adapatability Global COE
Graduate School of Life Sciences
Tohoku University
Osaki, Miyagi 989–6711
Japan
E-mail: htomi [at] bios.tohoku.ac.jp
Background
Postdoctoral fellow, University of British Columbia, 2007–2009
Postdoctoral fellow, Tokyo Metropolitan University, 2004–2007
Ph.D., Hokkaido University, 2003
Research
My research interests are in the ecology and conservation of plants. I am particularly interested in how natural or human-induced changes in environment
influence the dynamics of plant populations and communities, and the consequences of such changes for ecosystem functioning.
Current or recent topics of research include the followings.
Biodiversity and ecosystem functioning—Ecology has traditionally regarded environment and ecosystem processes as drivers of
biodiversity, while more recent research considers causality in the opposite direction with changes in biodiversity influencing ecosystem functioning.
Although recent research demonstrates overall positive effects of plant species diversity on ecosystem processes, even within a single plant species,
genotypic diversity can exert strong influence. In collaboration with Yoshihisa Suyama and Kazunori Nakano, we are conducting a small-scale experiment,
mimicking contructed wetlands, with manipulating genotypic richness of common reed (Phragmites australis).
We seek to understand how primary productivity and water quality (after nitrogen removal) are driven by genetic variability within
plant species through interactions between different genotypes and interactions between plants and root-associated microbes.
Response to habitat fragmentation—Habitat loss and fragmentation is one of the major threats to biodiversity.
There is also a concern that such biodiversity loss might significantly influence important ecosystem processes.
In collaboration with Masashi Ohara and many other colleagues, we have conducted
a series of studies addressing the consequences of forest fragmentation
for plant populations and communities and ecosystem functioning. In the Tokachi plain of Hokkaido, landscape was almost
completely forested before the Japanese began to settle here in the 1880s; however, subsequent intensive development had reduced
forest cover to <5% by 1950, resulting in a highly fragmented landscape. Using this landscape as a natural experiment,
our current project addresses the question of how tree communities and its above-ground biomass have changed over time following
forest fragmentation.
Plant dispersal and human involvement—Knowledge of dispersal processes is critically important for understanding many key aspects of plant biology,
including population dynamics, spatial genetic structure, and range expansion. Plant species have repeatedly shifted its geographic ranges in response to
long-term environmental changes, while the patterns of migration are contrained by geographic barriers such as mountains. Also, humans represent
an important vector of dispersal for many species, as clearly implicated in many episodes of exotic plant invasions.
In collaboration with Mark Vellend, we recently employed genetic analysis to examine the effects of past glaciation,
geographic barriers, and anthropogenic transport in Camassia quamash, which was one of the most important food plants for indigenous peoples in western North America.
Publications
Here is the list of my publications in international journals.
Click here for the complete list including Japanese publications.
Tomimatsu, H., Yamagishi, H., Tanaka, I., Sato, M., Kondo, R. and Konno, Y. (2011) Consequences of forest fragmentation in an understory plant community: extensive range expansion of native dwarf bamboo. Plant Species Biology 26: 3–12. [PDF]
Tomimatsu, H. and Ohara, M. (2010) Demographic response of plant populations to habitat fragmentation and temporal environmental variability. Oecologia 162: 903–911. [PDF]
Vellend, M., Drummond, E.B.M. and Tomimatsu, H. (2010) Effects of genotype identity and diversity on the invasiveness and invasibility of plant populations. Oecologia 162: 371–381. [PDF]
Tomimatsu, H., Kephart, S.R. and Vellend, M. (2009) Phylogeography of Camassia quamash in western North America: postglacial colonization and transport by indigenous peoples. Molecular Ecology 18: 3918–3928. [PDF]
Yamagishi, H., Tomimatsu, H. and Ohara, M. (2007) Fine-scale spatial genetic structure within continuous and fragmented populations of Trillium camschatcense. Journal of Heredity 98: 367–372. [PDF]
Tomimatsu, H. and Ohara, M. (2006) Evaluating the consequences of habitat fragmentation: a case study in the common forest herb Trillium camschatcense. Population Ecology 48: 189–198. [PDF]
Ohara, M., Tomimatsu, H., Takada, T. and Kawano, S. (2006) Importance of life history studies for conservation of fragmented populations: a case study of the understory herb, Trillium camschatcense. Plant Species Biology 21: 1–12. [PDF]
Tomimatsu, H. and Ohara, M. (2006) Evolution of hierarchical floral resource allocation associated with mating system in an animal-pollinated hermaphroditic herb, Trillium camschatcense (Trilliaceae). American Journal of Botany 93: 134–141. [PDF]
Tomimatsu, H. and Ohara, M. (2004) Edge effects on recruitment of Trillium camschatcense in small forest fragments. Biological Conservation 117: 509–519. [PDF]
Tomimatsu, H., Hoya, A., Takahashi, H. and Ohara, M. (2004) Genetic diversity and multilocus genetic structure in the relictual endemic herb Japonolirion osense (Petrosaviaceae). Journal of Plant Research 117: 13–18. [PDF]
Tomimatsu, H. and Ohara, M. (2003) Floral visitors of Trillium camschatcense (Trilliaceae) in fragmented forests. Plant Species Biology 18: 123–127. [PDF]
Tomimatsu, H. and Ohara, M. (2003) Genetic diversity and local population structure of fragmented populations of Trillium camschatcense (Trilliaceae). Biological Conservation 109: 249–258. [PDF]
Tomimatsu, H. and Ohara, M. (2002) Effects of forest fragmentation on
seed production of the understory herb Trillium camschatcense.
Conservation Biology 16: 1277–1285. [PDF]
