PARENT SESSION
Poster Session 7: Grasslands
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Biomass allocation of herbaceous plants and its importance for community assembly.

Tanaka, Ryoko^*,1, Koike, Fumito¹, ¹ Yokohama National University, Yokohama, Kanagawa, Japan

ABSTRACT- Biomass allocation is an important strategy for plants in communities under mowing, tramping, and cultivations. In this study, we examined biomass allocation of herbaceous plant species, and tested the significance of these traits on community composition of coppice forest, meadow and weed community in a rural landscape in Japan. The study area was a 1 km square, including four forest communities under different management, one meadow community and two seasonal weed communities. We randomly selected 42 species from 332 herbaceous species recorded in the area, and sampled reproductive individuals to measure weight of four types of organs; underground organ (root and underground stem), aerial stem, leaf, reproductive organ. Differences in allometrical traits of these species were examined for 5 community types. Species in the meadow community and managed coppice forests tended to have large biomass allocation to underground organs. Species in weed communities tend to have small allocation to underground organs. Species having leaves in coppice forest in dormant season (winter) had small biomass allocation to aerial stem, but large biomass allocation to leaf. Allometrical traits and 27 other ecological traits (shade tolerance, maximum-height, life span, etc) were used to predict species composition of various communities in a rural landscape using logistic regression analysis. Among the traits, shade tolerance was the most important for the forest communities and meadow community: These communities consisted of a subset of the regional flora that was characterized by plants having strong shade tolerance. Similarly, long flowering duration in a year was the key trait for the weed communities. Large biomass allocation to reproductive organs was selected as one of the significant traits for the summer and autumn weed communities, but another biomass allocation trait was not found for any communities. Biomass allocation was different between community types, however slightly significant traits determine community assembly.

Key words: allometry, plant ecological trait, community assembly rules, rural landscape