Evaluating the risk of bamboo species in the South-eastern USA
In the South-eastern USA, some bamboo species (Bambusoideae) are being promoted increasingly for paper pulp and biofuel production, as well as the more traditional use in horticulture. The sub-family contains over 1 600 species that are fast growing and often divided into running (leptomorph) and clumping (pachymorph) types based on the morphology of the rhizome system. Running bamboos can spread laterally over long distances during a single growing season whereas clumping bamboos have minimal spatial spread. To evaluate the risk posed by the two types of bamboos, the Australian Weed Risk Assessment (WRA) was used to screen the risk of 47 bamboo species from 11 genera including 18 running and 29 clumping bamboo species. The WRA tool consists of 49 questions that focus on estimating the probability that a species will become invasive in a new region by evaluating the climatic suitability of the species to the proposed range, the naturalisation and invasion history, life history traits and the ecology of the species and the effectiveness of current control methods. Most of the species selected for evaluation are currently under consideration for biomass planting or horticulture. For each species the WRA was completed answering each question and where climatic matching questions were evaluated using the USDA hardiness zone maps. The final scores were grouped for running bamboo species and clumping species and statistically compared. Overall, running bamboos were shown to have a significantly higher invasion risk compared to clumping bamboos and therefore these latter species should be utilised in commercial applications.
Sources
Lieurance D, Cooper A, Young AL, Gordon DR, Flory SL (2018) Running bamboo species pose a greater invasion risk than clumping bamboo species in the continental United States. Journal of Nature Conservation 43, 39-45.