What is Forest Botany?

History

Our laboratory was established in 1893 as the “Laboratory of Botany” in the College of Agriculture, Imperial University, as one of two laboratories (botany and zoology) that belonged directly to the College, independently of the educational courses. The first professor was Mitsutaro Shirai, who had graduated from the College of Science, Imperial University. In 1906, he became the first professor of the Laboratory of Plant Pathology, College of Agriculture. Early professors (Seiichiro Ikeno, who discovered the spermatozoid of Cycas revoluta; Shunsuke Kusano, who was the first president of the Japanese Mycological Society; Kiichi Miyake, a plant physiologist, and Kiyoshi Kominami, mycologist) also came from the College of Science.

After the establishment of the Laboratories of Plant Pathology (1906) and Hydrophytology (1911), the Laboratory of Botany focused on forest plants. In 1941, with the restructuring of the departments in the Faculty of Agriculture, Imperial University of Tokyo, the Laboratory of Botany was relocated to the Department of Forestry. In 1943, Taizo Inokuma, who graduated from the Laboratory of Forest Utilization, Department of Forestry, took over the Laboratory of Botany, and its name was changed to the Laboratory of Forest Botany in 1954 (see chronology).

Aims of forest botany

"Forest botany" is applied plant science that is aimed at contributing to forest management. It covers the taxonomy, morphology, physiology, ecology, genetics, and other aspects of forest plants and fungi. Forest botany has developed to include dendrology, tree physiology, tree pathology, and forest ecology in tandem with developments in traditional “botany”, such as plant taxonomy, physiology, ecology, and mycology. Recently, forest botany has also contributed to the development of arboriculture (tree health research and urban tree management) and natural environmental studies.

The aim of our research was to contribute to “tree and forest health” by accumulating knowledge on plants, fungi, and other organisms and their interactions. Forest botany covers a wide range of studies that should become the basis of forest management, the conservation of forests and rare species, urban tree management, and the control of tree diseases.

With global economic growth, forests are suffering from decline and degradation caused by climate change, agricultural development, urbanization, epidemic diseases caused by introduced pathogens, and the invasion of exotic species. Urban forests and trees also face many problems caused by forest fragmentation, heat island effects, air pollution, and other many anthropogenic stress factors. Forest botany also provides the basis of diagnosis and care by “tree doctors” (certificated arborists) who care for and manage urban greenery. Therefore, our studies and social activities are increasingly needed.

Major research themes

These are the three major themes on which forest botany should focus. (They are inter-related.)

Biology and ecology of forest plants and fungi: We study a wide range of forest trees, herbs, and microorganisms. For example, the taxonomy and reproductive ecology of trees and fungi are studied using DNA markers; the diversity of fungal endophytes in urban trees and natural forests are analyzed; and the influence of land-use history on the present vegetation is studied using aerial photograph analysis.
Stress physiology of trees: We study the physiology of individual trees under stresses such as drought, freezing, and infection by pathogens. Photosynthesis and transpiration measurements and anatomical and molecular biology tools are used to clarify the mechanisms of the health maintenance of trees. We also use custom-made magnetic resonance imaging (MRI) equipment to observe xylem water conduction in tree stems non-destructively, because “cavitation” in vessels and tracheids is one of the keys to understanding tree health.
Interactions between trees and microorganisms: Many microorganisms interact with trees, such as ectomycorrhizal and arbuscular mycorrhizal fungi, which assist in nutrient uptake by the roots, pathogenic fungi and nematodes, which cause tree diseases, endophytic fungi, which live in the healthy tissues of trees, cyanobacteria, which fix nitrogen in carpet mosses on the forest floor, and saprophytic fungi which decompose litter and wood debris to the forest soil. We study the ecology and physiology of these microorganisms to clarify their symbiotic and pathogenic interactions and their roles in ecosystem functions. Important targets include wood decay in street trees, mycorrhizal fungi, including matsutake, and pine wilt disease, which is one of the most severe forest epidemics worldwide.

last update: 2019/06/12