Heiberg Forest Report

Seed and Seedling Comparison in Two Tree Stands

The trees of Heiberg Forest vary greatly by area. One area could be heavily shaded by huge mature trees, with rich, cool and moist air. Another could be a much sunnier area, with younger trees and sapplings. Just a few steps can take you to a completely different atmosphere. There is a reason why certain areas are the way they are. Factors contributing to the trees of an area can range from land use history, soil quality, or human intervention. One leading component, perhaps the most important, is seed regeneration. The way a tree species disperses seeds to reproduce will affect its success in certain areas. Some trees disperse their seeds in a close range, some are carried by the wind, and others are carried by animals.

An experiment was conducted to analyze the seed and seedling dispersal two different areas of Heiberg Forest.

Two stands were chosen, one dominated by white pines and the other dominated by black cherry. Among these stands, groups were divided into plots to observe the prominence of species, seeds and seedlings. Observations were then averaged for each plot, and recorded in Figures 1 and 2.

The white pine stand had a rich vegetative understory. Since there wasn’t much of a canopy, more sunlight was allowed to reach the ground. This stand used to be used for farming, and was likely plowed over many times. This is evident in the landscape of the ground, which is fairly smooth. Covering the ground was a distinct layer of needles from the surrounding white pines. There generally seemed to be a majority of red maple and sugar maple seedlings (Figure 1). There was also an abundance of black cherry and red maple seeds (Figure

1).
In the black cherry stand, there was a denser canopy. Here, there were many more shade tolerant trees such as striped maple, and less of an understory. The ground was covered in a thick leaf layer, as a result of the abundance of surrounding deciduous trees. Unlike the white pine stand, this area was not used for farming, thus there were more hummocks and hollows. Seedlings found in this stand include black cherry, American beech, eastern hemlock, striped maple and red maple. (Figure 2) Although there was a more diverse set of tree seedlings, there were hardly any compared to the white pine stand. There were many black cherry and American beech seeds scattered across the ground. (Figure 2)
The black cherry stand had an incredibly higher number of seeds than the white pine stand. (Figures 1 and 2) This is because the dominant trees in this stand such as black cherry trees, disperse a great number of seeds within a close range of the parent tree. Some of these seeds can be further carried by mammals. Trees in the white pine stand, including white pine, depend primarily on the wind for dispersal. Since the black cherry stand had a denser canopy, it’s only logical that it had low lying vegetation. Its rich leaf litter also provides a better environment for plants and seedlings to grow.
There are many factors affecting the dominant tree species of an area. Seed dispersal is only one component, a piece to a much larger puzzle, for everything in nature is interconnected.