ARBORETUM NEWS (NATURALISTSNOTES)

Woodland Walk

TUESDAY, NOVEMBER 19, 2013

Sunday Walk on November 3rd: Woodland Walk
The weather was about 50 degrees and sunny; perfect for a walk through the woods. A lot of people thought it was a perfect day for a hike because over 60 people came along, which was the largest group I have ever had on a hike at the Arboretum! I am so grateful that so many people decided to come and enjoy the Arboretum on such a nice day.
We started our walk by going through the southern edge of Longnecker Gardens. As we hiked through the gardens I paused at the large White Pine trees and told everyone that earlier this Spring Red-Tailed Hawks built a nest there and had two young. We kept walking through the gardens and paused when we saw trees with very distinctive bark such as the Cork Tree and several Birch trees. We noticed that sometimes you can easily identify a tree by looking at its bark, but that we would see other trees that were not going to be so easy to identify.
We entered Gallistel Woods and immediately noticed the gorgeous yellow leaves on the maple trees. I explained that leaves do not really turn yellow, they always have a yellow pigment in their leaves, but during the spring and summer the yellow is masked by the green chlorophyll. During the fall the leaves do not need to photosynthesize and therefore they do not produce chlorophyll, so then the green color disappears and leaves seem to be turning yellow.
We walked past the shelter at Gallistel Woods – one the buildings left from when the Civilian Conservation Corps worked at the Arboretum. We also saw a tree with large oval-shaped holes pecked into it. After a few guesses someone shouted the correct answer to “Who made the holes,” which was a Pileated Woodpecker.

Holes made by pileated woodpecker

The Pileated Woodpecker is the largest woodpecker in Wisconsin and its large oval-shaped holes are very characteristic. We also saw small holes drilled in a nearly perfect line. These were marks of a Yellow-bellied Sapsucker. The Yellow-bellied Sapsucker is a very smart woodpecker; it drills holes in a perfect line that leak sugary sap from the tree, which lures insects. The woodpecker can then easily eat the insects that were attracted to the sap and also eat some sap itself; the sap is actually an important energy source for the woodpecker.
We continued walking through Gallistel Woods and paused at a Black Cherry tree. I noted that the bark of the Black Cherry tree reminds me of burnt potato chips and that I remember Burnt Chip (B.C.) for Black Cherry tree. We crossed the road to Wingra Woods and noticed that they were some trees in Wingra Woods that we didn’t see in Gallistel Woods. I wanted the group to get some experience identifying trees by using a key, so I pulled out several copies of “Forest Trees of Wisconsin How to Know Them” which is a book published by the Wisconsin DNR that has an excellent key in the back of the book. This book can be found in at the bookshop in the Arboretum’s Visitor Center. I explained to the group what alternate branching and opposite branching are. If you look at the image below taken from the WI DNR website, it may be easier to understand what I mean when I say that opposite branching is when two branches emerge from a single point and alternate branching is when you see a zigzag pattern emerge since one branch comes emerges on one side of a larger branch while a second branch emerges on the opposite side of that branch and further away.
We figured out that the tree we were looking at was a deciduous tree (deciduous meaning that it loses its leaves every year) and that it had alternate branching. The leaves were simple leaves, meaning that there was one single leave at the end of the stem. If there were several leaves all connected to a single stem by leafy material, then it would be called a compound leaf. The leaves of the tree looked wavy, like pieces of the leaf were missing; this is called a lobed leaf. Once we keyed out that we had a deciduous tree with alternate branching, simple leaves and that the leaves were lobed the key directed us to look at oak trees. After we looked through some pages describing different oak trees, we found the oak tree that matched our leaf, which was the White Oak.
We continued walking toward Lake Wingra and stopped once we reached a group of evergreen trees. We went through our key again and saw that we were looking at a Coniferous tree with needle-shaped leaves, each needle was individually stuck to the branch, which is called “Leaves Single” in our key, the needles laid flat, so that lead us to look at Hemlock trees and Balsam Firs. The group looked at pictures of Hemlocks and Balsam Firs and they were not sure which tree we were looking at. I showed the group the underside of the needles and everyone noticed two white lines. I said that the two white lines are characteristic of a Hemlock tree. Wingra Woods contains tree species that are native to the northern part of the state and Hemlocks are native to the northeast part of Wisconsin.
We followed the trail past the Big Spring and Overlook Prairie. As we continued walking we kept looking to our left and admiring the brilliant colors of all the deciduous trees that were peaking in color. We emerged at the trailhead “M3” and crossed the street into Longnecker Gardens once again. As we got close to the Visitor Center three turkeys crossed our path. Wildlife ecologists have counted one hundred turkeys in the Arboretum. We ended our hike at a perfect time for me because my voice was starting to get raspy after speaking loud enough for 60 people to hear me!
The group today discovered that identifying trees was not as hard as they thought it would be. They can even be identified without leaves, by the shape of their twigs and buds.

Samantha Bailey- Arboretum Naturalist

Located between Lake Wingra and the West Beltline Highway at 1207 Seminole Highway, the University of Wisconsin-Madison Arboretum features the restored prairies, forests and wetlands of pre-settlement Wisconsin. This 1,260-acre arboretum also houses flowering trees, shrubs and a world-famous lilac collection. Educational tours for groups and the general public, science and nature-based classes for all ages and abilities, and a wide variety of volunteer opportunities for groups, families and individuals are available.