Citizen Science Day 2018 | Identifying Leaves to Grow Knowledge, Skills, and Community
Editors note: is an electronic field guide developed by Columbia University, the University of Maryland, and the Smithsonian Institution. The app includes images of leaves, flowers, fruit, petiole, seeds, and bark from different tree species, and features visual recognition software that helps users identify a species of tree by uploading images of a leaf. It shares data uploaded by users, including the location and species, with scientists mapping the distribution of flora across the country and lets users view species documented in their area. Leafsnap is a great tool to use for Citizen Science Day on April 14, 2018.
For years I’ve been fascinated by Leafsnap, a free app produced by the Smithsonian that lets users in the US and Canadian northeast identify trees by snapping pictures of their leaves. I live and teach in a downtown neighborhood and pass hundreds of trees every day on my walk to school. Sadly, other than the distinctive maple and some oaks, I could never tell one from another: they were just filed under the broad domain of “trees”. I’ve always admired environmentally literate folks who can distinguish between different species and better articulate their surroundings. Fortunately, since I discovered Leafsnap, I now make the occasional stop to identify a tree that catches my eye and educate myself, a lifelong city dweller, on what Frank Loyd Wright called “our best friend on earth.”
Image: Leafsnap.com
Naturally, the teacher in me was eager to use Leafsnap with my students, but it wasn’t an easy fit with my English and media classes. This year, however, I took a new role to help teachers integrate game-based learning and technology, and immediately jumped on the chance to graft Leafsnap onto the curriculum. I gauged interest with Jeff Enfield and Phil Spacie, our two Grade 9 science teachers, who were both keen to give it a shot. Together, we worked out a three-class lesson where students would use a variety of resources and technologies, including Leafsnap, to create a basic inventory of the trees in and around our school campus. The project was launched in mid-September so that specimens could be gathered before the leaves turned and fell.
Class and Classification
After introducing the project, the first 75-minute class involved a deep dive into the function and anatomy of leaves. Students worked with handouts and activities to learn about photosynthesis, cellular respiration and the general configuration of a leaf. They also had a primer on the main features of a leaf used in the identification process.
The fieldwork took place in the second class. Groups of students ventured out in teams of two, equipped with mobile phones, clippers and printed Google maps of the campus. To avoid overlap and redundancy, we set-up a system so that each class gathered samples in different sectors of the designated survey area, and each team identified a different tree, which they manually marked on the map. They were tasked to clip 3 – 4 leaves, photograph the tree and its bark, and the leaves themselves were photographed in the classroom over a white background, as required by the app. The weather cooperated, and it was refreshing to see our Grade 9s cheerfully milling around campus and the neighboring park in the sunlight, snapping pictures and gathering samples. This not only bore the hallmarks of genuine scientific work, but it also created a nice change from the classroom routine and extended learning into the community.
Leaf identification, even with a helpful tool like Leafsnap, is not a perfect science. Trees can produce varying leaves that are not easy to discern, and irregularities in shapes can also fool the technology. The app provides a list of best guesses, but it’s a good idea to triangulate with other resources. In addition to Leafsnap, students were encouraged to consult Leaf ID and Ohio Public Library’s What Tree Is it? These sites each employ different methods for identification, and using them in conjunction with each other will produce more accurate results. In addition to that, students can also consult books and print charts, much like the naturalists of yesteryear. This process underscores that science, like nature, can often be “messy” and it’s often important to verify results in a variety of ways to ensure accuracy.
Maps and Pins
Once the teams determined whether they had a Swamp White Oak or a Norway Maple, they were tasked to mark-up the picture of their leaf and identify its parts, which they did using the Preview app that comes loaded on all Macs. Then it was time to bring it all together.
We created a Google My Maps of our campus and surrounding area and invited students to collaborate on a single custom map. Using their paper maps as a reference, they dropped a pin to mark the exact location of the tree they identified. Google map pins let users include images, text, videos, and even the color and icon of the pin itself can be modified. They conveniently compiled all their data on a single pin, including the name of the species (ideally both the Latin and common name), the names of the team members, whether it was native or non-native to the area, and a fun fact about that species. They also added their photographs of the tree, the bark and the labeled leaf. Once all the trees were pinned, the map provided a complete and detailed tree inventory of all the species in and around our campus.
Branching Out into the Community and the World
During the third and final class, the map was projected on the classroom screen and each team presented their pin to their classmates. We were surprised to discover that our little corner of the urban forest was populated by over a dozen different species, many of which were not native.
The presentations were followed by a discussion on the importance of urban trees and forests, which provide shade, oxygen, homes and food to wildlife, beautify neighborhoods, and offer a means to civic engagement. We visited the websites of volunteer groups, such as Neighbourwoods and the Arbor Day Foundation, that maintain tree inventories to monitor the health, care and diversity of trees in their community.
Finally, we tied their work to the United Nations’ 17 Sustainable Development Goals (SDGs), a 15 year UN sponsored project that aims to “end poverty, protect the planet and ensure prosperity for all.” The tree identification lesson met several SDGs, including Good Health and Wellbeing, Quality Education, Sustainable Cities and Communities, Climate Action, and Life on Land. Teachers can easily connect SDG’s to lessons across the curriculum, and use the #teachSDGs hashtag to share their work and network with like-minded educators and students around the world.
John Muir once said that “when one tugs at a single thing in nature, he finds it attached to the rest of the world.” In this case, we tugged on a leaf whose STEM led us to an experiential learning opportunity that wed classroom to fieldwork, theory to practice, raised global awareness, and fostered citizenship; an enterprise deeply rooted in the local community.
