See The Forest for the Trees

Field Observations

    7/22-7/24/2020

   

This week I decided to focus on trees specifically when making my field observations because so often we forget to see the forest for the trees, we focus on the bigger picture while obscuring the details. I've focused a lot on insect and wildflower life in my habitat so far which is why I wanted to focus on trees for once since it is Thomas Woods and thus trees make up the most vegetation biomass in my habitat. Using my 101 Trees of Indiana field guide, I looked at my search for trees to ID as a sort of scavenger hunt since I also had plans to incorporate it in this week's creative piece. I looked for trees that I didn't know and which had interesting looking leaves. From an artistic perspective, patterns of leaves, unusual or common shapes, and color were part of what I was looking for to catch my eye and to inspire me to play with. Something I realized from this process is that identifying coniferous trees is very difficult for me since I grew up more with deciduous and also I'm not as familiar with terms that describe pine tree parts. So often we don't know what we don't know until we are trying to figure something out, from identifying a tree to figuring out how to play ukulele. 

    

    Some other observations I made this week included finding an Eastern Harvestman chilling on a tree seedling with legs splayed out over the leaf. Ever since I was child I thought these long legged arachnids were cool and I often would let them crawl over my hand and giggle when they tickled me with their many feet. I also noticed some changes too. The log covered in mushrooms from a few week ago now had less surface area covered by mushrooms, which had shriveled and turned an orange-brown color. I also heard way less cicadas, if any at all, this week, whereas they were so loud in their song previously. I got to see one of my favorite butterflies flying quickly underneath the trees, a Tiger Swallowtail, its yellow wings contrasted against the forest of green. The catbird has been a welcoming presence in just about every one of my habitat visits as well and I shall miss it when it eventually migrates this fall/winter. 

Species Identification

White Ash Tree (Fraxinus americanus)

    

    Also called American Ash, the White Ash tree is a large tree, growing to a mature height anywhere between 50-80 feet. For identification purposes, the bark is typically a gray that is lightly colored and the bark forms in loose ridges and furrows. The tree's fruits are clusters of winged seeds. The leaves of this tree are compound which occur in opposite pairs with five to nine leaflets occuring on each individual leaf. In the summer months, the leaves are a dark green, and in the fall they change to a purplish color. It is due to this great height and purplish leaves that White Ash was used as an ornamental plant, as well as its wood is famous for being harvested to make baseball bats and church pews. Unfortunately, the invasive beetle species, Emerald Ash Borer, has caused many ash trees to have been lost to this parasite of ash trees or removed during management procedures of this invasive species. 

    Pictured to the right is a photo of a young White Ash tree that I identified which is why it looks so different. 

    White Ash trees are native to the Midwest, particularly Illinois and Indiana. They do best with exposure to full sunlight and prefer moist, well drained soils although they can tolerate drier sites as well. They have a moderate growth rate and are intolerant of drought. White Ash trees provide refuge  to many mammals, insects, and bird life. 

The Morton Arboretum. (2020). White ash (Not Recommended).https://www.mortonarb.org/trees-plants/tree-plant-descriptions/white-ash-not-recommended

Eastern Redbud (Cercis canadensis)

  

  Referred to as both Redbud and Eastern Redbud, this tree belongs to the Pea Family, Fabaceae. Typically they have a short trunk and then a very rounded crown of branches that spread out. When in bloom during springtime months of March-May, Redbuds have pink flowers that make this tree very distinguishable. The fruits of this tree are typically red/brown and can be 3.5 inches long. The leaves are smooth and heart-shaped and occur alternately on the branches. These dark green leaves also end at a pointy narrow tip. 

    The native habitat of these trees is woods, along stream banks, and limestone bluffs. Some of their adaptations include partial shade tolerance and low water use. Redbuds are also very beneficial to insect populations, especially native bees who are often endangered species. The nectar and pollen from the blossoms provides an important food resource for many insects. Humans can eat the blossoms as well, which have often been put in salads, breads, and even pancakes. The Redbud twigs have been used to make yellow dye by boiling in water as well. 

Lady Bird Johnson Wildflower Center. (n.d.). Cercis canadensis. https://www.wildflower.org/plants/result.php?id_plant=CECA4

American Beech (Fagus grandifolia)

    

    A tree by many names: White Beech, Red Beech, Ridge Beech, Beechnut Tree, and American Beech, this tree is a large, sturdy tree growing to heights of 50-80 feet tall. The bark is a light gray and is very smooth, and remains so throughout the trees entire life unlike most trees. The crown is rounded with many horizontal branches that spread out. The leaves are a glossy, dark green with veins that turn copper in the fall and remain on the tree most of the winter. (Pictured to the right is one such leaf that I used in my art project.) Beechnuts, produced by the tree, are vital to many food chains and many wildlife species depend on them for food, such as squirrels, bears, game birds, etc.

    You can find American Beech throughout the Midwest and Eastern United States, from Michigan to Florida and from Massachusets to Wisconsin. This tree species prefers moist, wet lowland habitats and can tolerate partial shade. One advantage it has is that beech trees can grow from the vast root system of a single tree, creating large groves. However, this comes with the vulnerability to disturbance in the root zone and drought as the roots are not deep but spread out horizontally. Another interesting fact is that the Early Hairstreak butterfly has evolved to have beech as the caterpillar's host plant. 

  Lady Bird Johnson Wildflower Center. (n.d.). Fagus grandifolia. https://www.wildflower.org/plants/result.php?id_plant=FAGR

Sweat Bee (Augochlora pura)

    Also known as the pure gold-green sweat bee, the Sweat Bee species Augochlora is a shiny metallic green or blue-green sweat bee that lives in the eastern United States. While solitary, these bees are known to live near neighbors as well, although they do not ever form a hive and the males do not help with the rearing of offspring. You can recognize these unaggressive bees by their shiny metallic colors and 12-13 antenna segments (males have 13 and females have 12). As their non-scientific name suggests, these bees are attracted to sweat which they will lick off of you, but they are very tame and almost never sting although the females are able to. 

    Sweat bees are important pollinators of eastern deciduous forests and similar habitats. Being generalists, they pollinate around 20 different flowering plants. One important species they pollinate are walnut trees of which they may be the only pollinator species that visits making them an important pollinator to these trees. However, the females only nest in rotting wood where they place a single egg in each cell that they make. The females place a ball of pollen and nectar inside the cells with the egg before closing it with a wax-like substance. Sweat bees are usually first active in spring when they emerge and can be found through summer and fall. Their habitat ranges from Quebec to Florida and Minnesota to Texas. In the south, you can find them from February to November and in the north they are active from April to September. 

Lucky, Andrea and Clancy A. Short. (September 2018). University of Florida. http://entnemdept.ufl.edu/creatures/MISC/BEES/Augochlora_pura.html

                                          Two Sweat Bees pollinating Tall Bellflower flowers

Question of the Week

Q: How might global climate change affect your ecosystem? Describe some specific pressures or changes your ecosystem might experience.

    One challenge of climate change is that varied weather/temperature cycles will impact organisms that evolved certain times to bloom for plants for example or time for insect larvae to hatch from eggs (this is called phenological volatility). If there is a mismatch that occurs due to early warm weather in winter for example, then organisms that depend on seasonal cycles such as temperature may bloom too early or hatch too early and die when the cold weather comes back or if the food source is nonexistent. I have observed many butterflies and moths in my habitat that could be impacted if their host plant blooms too early or too late when they hatch, such as monarchs and pawpaw moths.      

    Changing temperatures can also impact plant life that has adapted specific strategies for overwintering. Many tree species depend on snow cover to help insulate them from the wind and if we have less snow precipitation but still cold winters then trees can suffer more damage during the winter that may kill them. Trees can also suffer if their habitats change from more mesic sites to long droughts. Many of my tree species are drought intolerant and if Indiana suffers long droughts due to climate change they may not survive if they are too severe. This may mean that the tree species in Thomas Woods will shift to more drought tolerant and water conserving tree species over time. 

    Climate change also puts increased pressure on native versus non-native competition. Since many non-native species are from regions around the world with warmer climates, they may become even more advantageous here in more northern climates if our winters become warmer and shorter and our summers longer and hotter. As climate change causes more disturbances through floods, fires, and invasives, then generalists, many of them invasives, will be able to continue to compete with natives and their presence can be a disturbance in and off itself that perpetuates its own colonization of the landscape. Garlic mustard is a great example, which prefers disturbed soil and if you remove it, you can actually help it spread even more. Changes in weather may also lead to larger parasite populations, from more invasive beetles that eat and kill trees to more mosquitoes that will spread diseases that impact humans. 

    What is the response to this? Ecosystems may require more management in the future to reach stable states that still provide ecosystem functions and are relatively healthy. And of course humans must lower our carbon impacts, the largest of which come from military and industrial emissions. 

Creative Response

Below you will find a short series I made using pastels and leaves underneath paper to imitate a common childhood art activity. Unfortunately, the camera is unable to pick up some of the lighter colors which I promise are much prettier when viewed directly in real life. I found myself drawn to warm colors such as oranges and yellows, possibly because of my walk today outside, as well as cooler colors such as blue and green, often associated with the Earth. Can you tell what species of tree leaves I used? Answers down below after the photos. 

Leaf Collage by Jaime Reese

Answers:

White Ash, Redbud, American Beech, and unidentified but interesting large leaf