A Natural History of Charlottesville: Project Update February 2019

By Devin Floyd, Center for Urban Habitats

(Above: Blue Ridge-Piedmont Basic Woodland by Devin Floyd)

Between day jobs and family life, a dedicated crew of volunteer experts is chipping away at laying the groundwork for an interactive online resource that tells the rich story of Charlottesville’s Natural History. Here’s a quick project update.

Aquatic Macroinvertebrates of Charlottesville: 39 species of aquatic macroinvertebrates have been documented in Charlottesville’s streams to date. Bob Henricks (Central VA macroinvertebrate extraordinaire and photographer) has been the team leader for this subject area. Thanks to his contributions we’ll have some very beautiful photographs to share of these often overlooked animals.

The images shown here highlight three species that are active right now in the cold winter streams of Charlottesville: Allocapnia pygmaea (small winter stonefly), Taeniopteryx burksi/maura (large winter stonefly), and Rhyacophila fuscula (dusky free-living caddisfly).

Flora of Charlottesville: The Flora team for this project is led by CUH field tech, Drew Chaney. With Drew’s leadership, the flora team has documented 569 species of native and naturalized plants. Some of the more recent species added to the list include the city-county rare Pellaea atropurpurea (purple cliffbrake fern), Dryopteris goldiana (Goldie’s woodfern), Dryopteris celsa (log fern), and Asplenium trichomanes (maidenhair spleenwort). Other species recently added to the Cville Flora include Phoradendron leucarpum (American Mistletoe), Pinus rigida (pitch pine), Hibiscus laevis (halberd-leaf rose-mallow), and Doellingeria infirma (cornel-leaved aster).

Rocks and Minerals of Charlottesville: Work this winter has been focused on confirming the locations of the margins of the city’s major geologic formations. Within each formation there resides far more detail than has ever been mapped. This has important implications for natural plant community development, as geologic variation creates variety in ecosystems.

Featured in the images are rocks of the recently named Biscuit Run formation. These are complicated rocks and represent a time in Virginia’s geologic history that is not all that well-represented or understood. Mapping the geology will help predict plant community types, and the plant community mapping team will discover detail that is of interest to the geology team!

Fish of Charlottesville: Thanks to the contributions of local environmental scientist and fish whisper, Tamara Doucette, we have a fairly good baseline list of species for Charlottesville. In the list of more than 50 species of fish are several notable species, including a most unexpected catch and release of a sea lamprey (Petromyzon marinus) near the mouth of Moore’s Creek!

Efforts in 2019 will be focused on figuring out how to get an accurate estimation of diversity in Charlottesville’s smaller streams and floodplain wetlands. They must be sampled evenly to include all types of aquatic habitat, such as riffles, runs, pools, ponds, impoundments, swamps, and vernal pools. The first step toward accomplishing this work will be to map and prioritize these habitats and their features. Artwork by Ellen Edmonson, State of New York (Wikimedia commons).

Old Forests of Charlottesville: Yes, you heard that right! Most of the trees around town were either planted or allowed to regrow after development sometime in the 1800’s-1900’s. But, in some areas we actually find large patches of what appear to be intact forest canopy from woodlands and forests that existed as early as 1750.

We are using historic aerial imagery (1937-present) to confirm continuity in the canopy structure through time. The oldest forests show up first as groupings of enormous tree crowns in the old 1937 images. A few of them remain unchanged through the entire history of aerial photography up until this year.

To confirm “old growth” status we are using a tool called an increment borer. This device allows us to extract a small-diameter cylinder (about the size of a straw) from trees which, in turn, allows us the chance to count the annual growth rings to estimate age. The age of a tree is always a mystery. Some of the smaller trees exceed 200 years old, while some of the giants can be less than 75 years old. By utilizing annual growth rings and comparing to other specimens we can confirm the ages of individuals and groups of individuals. Stay tuned for more. It is a primary objective of this project to provide information so that you can visit the last remaining old growth forest remnants of Charlottesville.

Natural Plant Communities of Charlottesville: You may ask, “What is a natural plant community?” You hear the words, “ecosystem” and “habitat” thrown around quite a bit. But, in most cases, those are used very loosely, with no clear definition of what they mean; nor a communication about size or specific predictable characteristics. Well, gratefully, there is something less ambiguous. As it turns out, there are many different types of natural plant communities that have been here in Charlottesville forever (despite the heavy hand of humans). They are easily recognizable and they all have names. In Charlottesville, we hypothesize that there are about 50 types. Scientists in Virginia call these unique and predictable ecosystems, “Natural Plant Communities”.

A goal of this project is to identify, map, and document all the types of natural plant communities in Charlottesville. To confirm the identity of natural plant communities in the city, we do science. The process is simple, conceptually. We put a large square in the woods (400 sq. meters; 20 x 20), and we identify and count every plant in each of six (sometimes seven) layers of the forest, from the ground level up to over 120 feet high (if applicable). We also estimate the abundance of each species. This results in a whole lot of data that can be used to find the specific classification (name/type) for each plant community. A few examples that we confirmed in Charlottesville in 2018 are: Piedmont/Central Appalachian Floodplain Swamp (Silver Maple – Green Ash Type), Piedmont Acidic Oak – Hickory Forest, Piedmont Rich Floodplain Forest, and Inner Piedmont Basic Mesic Forest.