New Jersey is home to large forested areas, covering about 40% of the state. The two dominant forest types are oak/hickory and loblolly/shortleaf pine with subgroups existing in these greater types (Crocker, 2018). Given their dominant presence, I was curious to view their beauty on a microscopic scale. With the Princeton forests as my lab space and the foldscope as a tool, I began my exploration

With plenty of leaves on the ground, I sought to find a leaf that had not fully succumbed to the darker, fall color changes. I wanted to examine the greener areas of the leaf and compare it to the yellow-orange areas to see how if on a smaller scale, or perhaps a cellular level, there would be stark differences. For the purposes of this post, I only included the green area of the leaf as the yellow-orange areas were difficult to visualize without strong lighting that was difficult to capture in a camera lens (Figure 1).

Figure 1: Microscopic snapshot of what appears to be plant cells of a yellow-green leaf found on Princeton's campus.


Seeing the leaf under the foldscope was truly amazing. I was excited to see what appeared to be plant cells, similar to what Robert Hooke first saw several centuries ago. I was struck by the varying shapes and sizes of what appears to be the cell walls. I wonder what factors contribute to these various shapes and sizes. I am still curious as to what the yellow-orange colored leaves would have looked like under the foldscope. Given the uneven color in the posted photograph where other areas are more yellow than green, I predict that yellow-orange colored leaves would also have yellow-orange structures at a cellular level.

I was very happy to have done this exercise. Being able to build an instrument and engage in the scientific process, all in under two hours is truly amazing. An interesting future project could compare leaves at a cellular level through the foldscope under different conditions such as varying precipitation and temperatures. The foldcope could allow observers to potentially gauge the health of the leaves at a cellular level.

Ecology is everwhere; the foldscope just gives you another set of eyes to look.

I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University. - JCalimag

References

Crocker, Susan J.; Nelson, Mark, D. 2018. Forests of New Jersey, 2017. Resource Update FS-167. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 4 p. https://doi.org/10.2737/FS-RU-167.