question: What is pollarding
answer: The willow was harvested using a traditional method of pollarding , where a tree would be cut back to the main stem
turker_answer: Pollarding is where the willow is harvested using a traditional method , where a tree could be cut back to the main stem .
rule-based: Pollarding is the willow was harvested using a traditional method of pollarding , where a tree would be cut back to the main stem