Opuntia other locations. Prickly pears (mostly "Opuntia stricta") were originally imported into Europe during the 1500s and Australia in the 18th century for gardens, and were later used as a natural agricultural fencing and in an attempt to establish a cochineal dye industry. They quickly became a widespread invasive weed, eventually converting of farming land into an impenetrable green jungle of prickly pear, in places high. Scores of farmers were driven off their land by what they called the "green hell"; their abandoned homes were crushed under the cactus growth, which advanced at a rate of per year. In 1919, the
Plant functional type key parameters are defined, such as fecundity, competitiveness, resorption (rate at which plant decays and returns nutrients to the soil after death), etc.; the value of each parameter is determined or inferred from observable characteristics such as plant height, leaf area, etc. Climatologists and ecologists struggle to determine which minimal set of plant characteristics best model the actual responses of the biosphere in response to climate changes. Plant functional type Plant functional types (PFTs) is a system used by climatologists to classify plants according to their physical, phylogenetic and phenological characteristics as part of an overall effort to develop a