title: Plant biomechanical strategies in response to frequent disturbance: uprooting of Phyllostachys nidularia (Poaceae) growing on landslide-prone slopes in Sichuan, China.
abstract: Bamboo is considered useful for controlling landslides, but we observed numerous shallow-slope failures in forests of big node bamboo (Phyllostachys nidularia) in Sichuan, China. Therefore, we inventoried landslide occurrence and vegetation type along one valley. To quantify bamboo root anchorage, we performed uprooting tests and measured plant morphological characteristics. Landslide occurrence was greatest at sites with bamboo and young trees. Culm failure was common because of the high length to diameter ratio (242 ± 6). Uprooting tests showed that the maximal force to cause failure was small (1615 ± 195 N). Uprooting force was strongly and positively regressed with a combination of the predictors lateral root number and volume (R(2) = 0.92), and root systems were highly superficial (depth = 0.15 ± 0.12 m), contributing little to slope stability. In P. nidularia, which grows on landslide-prone slopes, surprisingly few resources have been allocated to anchorage. We suggest that this strategy puts this pioneer at an advantage on steep slopes, where it contributes little to slope stability and colonizes frequently formed gaps through vegetative regeneration. Fewer disturbances would result in subsequent secondary succession and dying back of this shade intolerant species.
authors.affiliation: Institut National de la Recherche Agronomique (INRA), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Chinese Academy of Sciences-Institute of Automation (CASIA), P.O. Box 2728, Haidian District, 100080 Beijing, China;
authors.forename: Alexia
authors.initials: A
authors.lastname: Stokes
authors.forename: Adrien
authors.initials: A
authors.lastname: Lucas
authors.forename: Luc
authors.initials: L
authors.lastname: Jouneau