1. Other criteria that should be considered for determining species replacement are: tree physiology such as growth, seed dispersal and maturity. Ecological features should be considered. Feathers such as soil type, drainage, seedbed type, and nutrients. Successional stage of the current forest should also be considered as well. Tree physiology is important to determine what species would replacement. Characteristics that allow tree species to grow fast and tall, allow for the species to be shade intolerant (Bruns and Honkala, 1990, OMNR, 1998; OMNR, 2000; Homes, 2006; Matonis et al, 2011). This characteristic is found in many pioneer species such as: Fraxinus americana, Betula papyrifera Populus tremuloides, Populus balsamifera, Populus grandidentata, all which can be found in the South Drumlin Nature area. Also, the physiology of shade tolerant trees are also as important as shade tolerant species such as Acer saccharum, Fagus grandifolia, Tusga canadensis and Ostrya virginiana are facilitators species (Bruns and Honkala, 1990, OMNR, 1998; OMNR, 2000). These species are able to facilitate the environment around them to be suitable for their own species. A study by Woods (1984) found that the canopies of some species are able to influence the area around it. Canopies from species such as Tusga canadensis and Tilia americana discriminate against other species, while the canopy from Acer saccharum favours Fagus grandifolia (Woods, 1984). Matonis et al (2011) suggest that there are multiply variations that influence gap regeneration and that great light availability would be most suitable for species such as Fraxinus americana ; Populus balsamifera, Populus grandidenta and Butula papyrifera.
Many other studies (Poulson and Plati, 1...
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...on from beavers and deer may result in the loss of the main stem. This may cause other stems to sprout out and compete for the role of the main stem (Bruns and Honkala, 1990).
The guideline used in this lab is not a reasonable one as it does not take into account density. As stated before, density can greatly influence the crown diameter of a tree. I think that a guideline that could determine the average crown diameter should include other factors such as: average density, tree height and proximity to edge. The variable “proximity to edge” is an important as trees found near exposed areas then to have larger crowns, as the tree will put more energy to lateral growth (toward direction of most sunlight ) than vertical growth. This can be seen in a study by Clark and Schlarbaum (2003) found that trees that were not shelter and then exposed to light were 65% taller.