curious correlation. When paper birch saplings were weeded out from clear-cut and reseeded plantations, their disappearance coincided with first the deterioration and then premature deaths of the planted Douglas fir saplings among which they grew. Foresters had long assumed that such weeding was necessary to prevent the young birches (the ‘weeds’) depriving the young firs (the ‘crop’) of valuable soil resources. But Simard began to wonder whether this simple model of competition was correct. It seemed to her plausible that the
