The effects of crowding and distance to forest edge on dbh in Acer saccharum

Data was collected from the Danby Woodlot at York University’s Keele Campus to assess the effect of distances to forest edge as well crowding on the diameter at breast height of Sugar Maple Trees, <em>Acer saccharum</em>. 25 metre long belt transects were set up from the forest edge – defined by the furthest adult tree from the centre of the forest – and extended inwards towards the centre of the forest. In total, 30 transects were set up over two field data collection sessions on October 15th and 22nd, 2014.The location of placement of each transect was decided using pseudo randomly selection inwhich a random number generator was used to select from one of four randomly selected spots at the forest edge, each chosen by one researcher. All adult Sugar Maples within 0.5 metres of the belt transect were sampled. An adult was defined as a tree of at least two times the height of the average researcher, about 3.3 metres. Distance to forest edge was measured as the distance from the sampled Sugar Maple to the starting position of the transect at the forest’s edge. For each sampled Sugar Maple tree the distances to the nearest three adult trees were measured using an additional belt transect to the nearest centimetre. The mean of these three distances was later calculated to represent the amount of crowding around the sampled tree. Only living Sugar Maple Trees were sampled and Sugar Maple Trees were identified by the distinctive shape of their leafs..