Welcome to my blog! 

Follow along as I take you on a journey exploring the waters of the Shenandoah watershed.

Dendrology

As I walk through the Shenandoah watershed, I notice that the trees near the stream and riparian areas differ from those found near the peaks and mid-slopes. Each area of the watershed serves its own ecological function, and the tree species vary accordingly. I will later discuss each of these species in more detail, but for now, I want to highlight the importance of their locations within the watershed and identify which species you’re likely to encounter.

The hillsides of the watershed are covered in thick forests. The upper slopes and ridgetops of the mountains are dominated by several varieties of oaks and white pine trees. These dense forests stand tall at higher elevations, shielding the lower slopes and valleys from strong storms and winds. The oaks and pines have strong, spreading root systems that anchor the ridge tops, helping to reduce erosion and maintain the stability of the upper slopes.

The mid-slopes feature a more diverse mix of trees, including ash, birch and hickories. These mixed hardwood forests play a vital role in stabilizing the steep terrain, reducing the risk of erosion and landslides. This, in turn, decreases sediment runoff and helps protect water quality downstream. The mid-slope forests contain trees of varying sizes and downed trees, which provide essential corridors and habitats for plants and wildlife throughout the watershed. There are also dead and decaying trees and leaf litter which help build the soil fertility and support decomposers, which are essential for biodiversity and the overall health of the forest. These mid-slope forests support both the physical stability and the biodiversity of the region.

On the lower slopes, trees such as tulip poplar and red maple are common, along with understory species like pawpaw and mountain laurel. This diversity thrives in the increased moisture of the lower elevations, where it helps filter nutrients and pollutants from runoff before they reach the waterways. These functions are crucial for maintaining water quality for aquatic life and downstream communities. The dense root systems also stabilize stream banks, reducing erosion and acting as natural buffers during floods.

In the floodplain and riparian zones, species such as cottonwood and American sycamore are commonly found. These floodplain forests help filter out sediments, nutrients, and pollutants before they enter rivers and streams, ensuring cleaner water for aquatic ecosystems. Additionally, they absorb excess water during floods, reducing flood severity. Their dense roots and understory vegetation stabilize the soil and stream banks, minimizing erosion and sediment flow into waterways.

The image below shows the varying slopes found throughout a watershed.

Credit: https://www.sciencedirect.com/topics/earth-and-planetary-sciences/floodplain-forest

References:

Flathead Watershed Council. (n.d.). Floodplains. http://www.flatheadwatershed.org/watershed/floodplains.shtml

National Park Service. (2024). Trees and shrubs. Shenandoah National Park. https://www.nps.gov/shen/learn/nature/treesandshrubs.htm