Blog Post 3: Ongoing Field Observations

1. The organism that I plan to study is the white spruce (Picea glauca).
2. The gradient that I will be analysing is the amount of space between trees from very crowded to 3m apart. This distance is an average of the distance between tree trunks at ground level. The most crowded location (location 1, annotated in red, Figure 1) is the forest stand at the north end of my study site; the mid-level spacing (location 2) is a cluster of trees near the house (annotated in blue, Figure 1); the location with the furthest distance between trees (location 3) is at the north west corner of the study site (annotated in black, Figure 1). Figure 1.

These trees were all planted by my family about 10 years ago. I am planning to study and compare various patterns within the white spruces. These patterns consist of tree height, new growth/bud abundance, and DBH (diameter at breast height). I plan to use tree height and DBH to calculate biomass, which can be used to determine productivity through a regression model based on the relationship between DBH (cm) and biomass (kg). There are many opportunities for comparison.

3. The most obvious underlying process that may cause observed patterns is the amount of direct sunlight received by an individual. Another might be any limiting of a resource due to a higher density of individuals in the area. It is hypothesized that overcrowding of white spruce (Picea glauca) decreases overall productivity and ability for seasonal growth (budding). If trees have more space between each other, they will be more productive due to more available sunlight and resources. Trees that are subject to crowding will be less productive than those that have ample space to themselves. For example, I predict that location 1, the most crowded, will have higher competition for soil resources, which may restrict growth. In contrast, trees in location 3 may have more room to spread their roots and absorb sufficient resources.

4. One potential response variable is whether the white spruce (sample unit) is crowded or spaced. A potential response variable is the abundance of new buds or tree height. These variables will both be continuous, as they will both be measured on a numeric scale (centimetres or metres for distance between trees and height; number of buds).