Barrier to restoration: the decomposition rate of bridal creeper's root system

摘要

Bridal creeper (Asparagus asparagoides (L.) Druce) is an environmental weed with extensive rhizomes and storage tubers forming underground mats. This geophyte has been recognised as a Weed of National Significance in Australia as it has the potentialto dominate native vegetation both above and below-ground. The litterbag technique was used to determine the decomposition rate of bridal creeper's belowground biomass. After a rapid loss of about 40% of biomass in the first three months, decomposition then slowed dramatically, indicating that decomposition may take many years for completion. In Western Australia, the nutrient concentrations of this belowground biomass were similar to other geophytes, except for high levels of iron and manganese. The belowground dry weight of bridal creeper was estimated at 2.99 +- 0.32 kg m~(-2). This biomass was concentrated in the top 20 cm of the soil profile. Weed control methods and restoration activities will need to take into account the residual effect of thisbiomass.