WILLISTOWN CONSERVATION TRUST

DONATE

The Power of Trees in a Watershed

By

Trees that grow along waterways play a critical role in maintaining a healthy stream or river. Trees provide a huge list of benefits: from providing habitat and food to stabilizing banks and cleaning the water – trees do it all.

The Riparian Zone is the area of land that borders a waterway. This zone is very important for maintaining the health of the stream, and the trees and plants that grow in this area play a critical role in the function of a stream. Riparian trees provide a huge list of benefits: they shade the water to keep it cool, provide food and habitat, stabilize the banks of the stream and filter water to remove pollutants.

A mature leafed out canopy of a tree provides shade from the direct sunlight and keeps the water cooler. Many of the streams in this area are fed by ground water, which means that in a healthy system the water should be very cold. Cold water holds higher levels of oxygen than warm water, and as the stream water begins to warm up, oxygen levels can quickly decrease to the point that many kinds of stream life can no longer thrive. In many cases, streams can warm to the point that some stream life cannot survive. While many different things can cause a stream to warm up, one of the most obvious is a lack of riparian trees. Direct sunlight on a slow moving stream in the heat of August can rapidly warm the water, but by planting riparian trees this can be avoided.

A healthy riparian zone full of trees also provides food and habitat in the stream. In healthy headwaters or the start of a stream or river, the most important source of food is the leaves and branches that enter the waterway. This is called detritus, and is the foundation of the food pyramid. Major inputs, like the falling leaves in autumn, will feed the ecosystem through the entire winter. The leaves that fall into a stream get caught on rocks and sticks and form leaf packs, which are nutrient rich bonanzas for the stream ecosystem! For this reason, it is important that when replanting riparian areas that native plants are used, as many non-native plants do not have the same nutritional value, and will not be consumed when they enter a waterway. Trees and branches that fall into waterways also provide important cover and hiding places for many stream species. The fry, or baby fish, needs a cover to avoid being eaten by larger animals. In a natural undisturbed stream system, there would be log jams, snags, and loads of leaf packs in a waterway to provide this cover.

The canopy is not the only important part of the tree for our streams – the roots of a plant in a riparian area serve the important purpose of stabilizing the banks and slowing the rate of erosion. Erosion is a natural part of a stream’s life, but the rate of erosion can become a problem. When plants are removed from the banks, there is little to secure the soil and rocks along the edge of the waterway, and as rainfall causes water levels to rise and speed up, the force of the water begins to carry the loose bank downstream. This results in stream banks becoming steep, undercut and unstable, and large deposits occur downstream, which can smother existing stream life. Organisms like mussels can become buried underneath sediment that arrives rapidly from upstream erosion.

This May, the Watershed Protection Team is planting 250 trees at Ashbridge Preserve, and we need your help! Join us from May 23 through May 29 in populating the meadow at Ashbridge Lake with a diverse set of native trees and shrubs. This year, the tree planting is designed to take place over an entire week to allow for multiple small groups to come out and make a difference while staying safe and following COVID safety guidelines. We are doing our best to keep all volunteers safe while improving the habitat along Ridley Creek!

 

To access this year’s planting, we will need to cross Ridley Creek, so please come prepared in shoes that can get wet and muddy! Please bring your gloves and water bottles to stay hydrated during the planting.



This planting has been made possible by generous funding from the DCNR.

Darby Creek Headwaters Monitoring Program

By

The Watershed Protection Program has teamed up with Darby Creek Valley Association (DCVA) and Stroud Water Research Center to create a citizen science water monitoring program in Darby Creek! This collaborative project aims to create a network of training and mentoring opportunities to empower the neighbors of Darby Creek to collect high quality stream data and become water advocates for their community. The long-term goal of this project is to use the information collected from Darby Creek to advise restoration decisions, like choosing the most effective location to improve riparian buffers or the best place to install a rain garden to slow down storm water entering the stream. Detailed monitoring data will also help to identify pollution sources and areas of the landscape that pose a risk to watershed health and integrity. Cultivating a stronger understanding of the waterway takes time and effort, and we are looking to the community for help!

Training for this program will focus on safety, data quality, and education on watershed ecology and the influence of humans on waterways. Individualized training will be provided to each volunteer to ensure that every person is confident in safety protocols and how to collect high quality data and water samples. In addition, volunteers will learn more about how human activity and landscape development affects the health of waterways beyond the borders of the headwater region. The creation of a volunteer network will provide a platform for volunteers to become stream advocates who are knowledgeable about current issues in the watershed and can speak to both the needs of the waterway itself, as well as the surrounding communities.

While the Trust is focusing on the headwaters of Darby Creek, our partnership with DCVA ensures that this program is being implemented throughout the entire Darby Creek Watershed. This whole-watershed approach will provide opportunities to learn about how the waterway changes as it moves downstream and will highlight challenges that local communities face such as flooding, thermal pollution, freshwater salinization, and erosion and sediment problems and will provide a foundation to address those issues. The data we collect will help address these concerns starting at the origin of the stream, right in the Trust’s program area. Our waterways are a valuable part of our environment and are a reflection of the health of the entire landscape – the more we understand how they are being impacted by human activity (and protected by highly valuable forests and wetlands), the more effective we can be at preserving and restoring them.

We are looking for volunteers! To learn more about this program, email lbm@wctrust.org, and to become a volunteer, contact director@dcva.org.

  • Darby Creek. Photo by Sue Miller,
    Darby Creek Valley Association.
  • Darby Headwaters Team.
    Photo by Evan Hunt.

Road Salt and Its Impact on Fresh Water

By

As winter quickly approaches so does the threat of salt pollution. Since the 1940s, salt has been the number one choice for fighting road ice in the United States. Over the last five years, PennDOT used an average of 844,000 tons of salt per year to keep Pennsylvania’s roads free of ice during the winter months. As effective as salt is at melting ice, it can cause major environmental problems after it washes off roads and into nearby waterways. Scientists have known for a long time that salt can be a serious pollutant in freshwater ecosystems, affecting multiple species of fish, insects, amphibians, and plants. More recent studies have shown that road salt is the main culprit of salt pollution in the northern United States.

According to a USGS survey, 84% of streams in urbanized areas of the northern United States have seen increases in chloride levels attributed to road salt. While 40% of streams have experienced levels that are considered dangerous to aquatic species. Furthermore, 29% of those streams have seen spikes in chloride levels during the winter that would make the water unsafe for drinking. 

Armed with this knowledge, PennDOT and local municipalities have made efforts to limit the amount of salt laid on roadways. PennDOT limits salt treatments to high-traffic areas and dangerous intersections or curves. At the same time, municipalities have started mixing sand in with salt to improve traction and reduce the overall amount of salt used. Unfortunately, these changes might not be enough as private businesses and homeowners still contribute significantly to the amount of salt introduced into the environment. Over-salting of sidewalks and parking lots is far too common since private snow shovelers are understandably more concerned with the safety of pedestrians than the environmental costs associated with using salt. 

However, there are ways to achieve a balance that prioritizes safety while also taking into account the risk of salt pollution. The most straightforward solution could be sweeping up salt from sidewalks after the ice has melted but before a snowmelt or rain event can wash the salt away. Not only does this prevent salt from reaching our freshwater ecosystems but the salt can be reused during the next snowstorm to save some money. Adding salt before snowfall rather than after is another technique that could reduce the amount of salt needed to keep sidewalks free from ice. Another option is to reduce the amount of salt used by cutting it with sand or even beet juice like some Canadian cities have successfully experimented with. All of these methods can be implemented by anyone who finds themselves shoveling snow during the winter.  

Even those of us who do not have any snow shoveling responsibilities can play a big part in addressing this issue. The Izaak Walton League is a national organization that trains citizen scientists to measure the amount of salt in their local streams, especially after snowstorms. This kind of data can help determine the local impact or source of salt pollution. Maybe more valuable, measurements collected by citizen scientists will increase the national dataset used to help scientists and policymakers make decisions about mitigating the effects of our increased reliance on road salt.

For more information about becoming a volunteer citizen scientist, you can visit iwla.org.

From Tops of Trees to the Base of the Food Chain

By

There is a chill in the air and the leaves are starting to turn, signaling that fall is here! Have you ever wondered what happens to the leaves that fall every autumn?  When the trees shed their leaves, the leaves continue to play an important role in the environment. They fall onto the land and return the nutrients back into the soil or blow into streams, where they are vital in sustaining our freshwater ecosystems through winter months.  As the leaves gather in our waterways, they get caught on rocks and on sticks and form masses called leaf packs.

Leaf packs are so much more than just bundles of leaves and sticks. They are nutrient rich pockets in the stream that provide cover and food for a wide diversity of stream insects. Raw leaves that enter the stream are hard to for insect larvae to eat, and need to be broken down before they can be consumed.  When leaves enter the waterway, they quickly become coated in a slimy biofilm, a name for a collection of algae, fungi and bacteria, which work quickly to condition leaves and turn them into a more palatable meal for macroinvertebrates. Some insects, like stoneflies, prefer to scrape the biofilm off of the leaves while others, like mayflies enjoy eating the leaf itself! As the leaf is broken down by the biofilm or shredded by insects, nutrients get carried downstream by flowing water and provide sustenance for other parts of the stream. Insects like caddisflies, live just downstream of the leaf packs and collect the floating leaf particles to eat.

Aquatic insects are a discerning group of organisms, and have preferences in what leaves they consume. Just as you and I may not order type of food at a restaurant, not all insects will prefer the same leaves! It has been documented that stream insects prefer native plants to non-native plants, and most insects studied have preferred types of native plants. It is important to have a diverse community of trees and shrubs along our waterways to provide a variety of leaves every fall to feed the aquatic community.

Leaf packs sustain a variety of insects throughout the winter months, and the annual addition of leaves into our headwater streams is critical for the health and survival of the aquatic ecosystem. These leaves feed the insects at the base of the food chain, which in turn feeds the many fishes, birds and mammals that rely on streams to survive.  We can be good stream stewards by planting a diverse community of native trees and shrubs along waterways and leave leaves where they fall to allow the nutrients to be reincorporated into the ecosystem to sustain another generation of life!

You can learn more about leaf packs from our friends at Stroud Water Research Center here!

Stonefly larvae are scrapers or grazers and eat the biofilm off of leave.
Predators exist wherever there is prey!  This dragonfly larva hunts the shredders and grazers in and around the leaf pack, and nutrients from the leaves are transformed up the food chain.

Mayfly larvae are shredders, and prefer to eat leaves which have been conditioned by biofilm.
Leaf packs gathering in Okehocking Run at Rushton Preserve.

Watershed Department Bids Farewell to Drexel Co-ops

By

Co-ops participating in fish electroshocking research with the Academy of Natural Sciences and Willistown Conservation Trust this summer.

Willistown Conservation Trust (WCT) is proud to participate in Drexel University’s Co-op program. Each year, from April to September, students join our Watershed Department to gain hands on field experience and learn from each of the different departments at the Trust. When Zack and Jules Smith joined the watershed team this spring, the Trust was already in lockdown. The whole team (Lauren, Evan, Zack and Jules) was not able to get together in person, so we met digitally, hoping that each week that we met via Zoom would be the last. Despite the many adjustments that set this co-op cycle apart from previous co-op  experiences, Zack and Jules showed that they had the adaptability of any great field researchers and were able to quickly join in the conversation and meaningfully contribute to the progress of the Watershed Protection Program.

Jules Smith

Jules:

When my co-op at Willistown Conservation Trust began at the beginning of April, I had no idea what to expect but the past few months have been nothing short of spectacular. One of my favorite parts of my co-op was participating in journal club discussions with the watershed team. Each time one of us presented a new topic connected to the work that is done at the Trust. I was continually learning new things, both from the papers we read and from Lauren, Zack, and Evan. Everyone’s willingness and eagerness to discuss such a wide range of science gave me new perspectives that I will carry with me long after my time at the Trust has ended.

The field work I was able to participate in allowed me to develop a deeper appreciation for land conservation and understand the importance of proper preserve maintenance. Tree planting and stewardship days were especially impactful as I gained hands-on experience in caring for native plants. I loved being able to lend a hand in keeping the preserves beautiful for everyone who comes to enjoy them.

Zack Smith

Zack:

Coming into my co-op at WCT I was expecting an experience that was mainly field work based and required working in close proximity to other people, but as the Coronavirus pandemic settled in it was apparent that was no longer going to be the case. This change was confusing at first but ultimately provided a unique co-op experience. The past 6 months have emphasized the importance of flexibility. Though I was eager to start working in person I had to remind myself that times have changed, and I need to be able to adapt to the situation.

This theme carried throughout my time at WCT. The remote work that we did was pretty refreshing and educational. I really enjoyed searching for a report of the week and reading all about a genus or species only to change my mind a few hours later and do it all over again. Our long and meaningful discussions about diversity, equity, inclusion and justice have provided a much different experience than I was expecting. I feel like I have learned a lot about myself, society, and others through these conversations and I am grateful for the safe space we had.

Lastly, the weekly field days in the latter half of the co-op were such a treat and an even better break. Going in and getting that person-to-person interaction while doing physical work on the preserves was rewarding in many ways. Though the co-op didn’t look like I expected, at the end of the day it was an invaluable opportunity that provided many different experiences necessary to growing as a person and a scientist.

Although this summer did not go as anyone on the Watershed Team planned, it was a rich and wonderful experience to be joined by such dedicated and passionate researchers.  The contributions of Zack and Jules have made a strong impact on the department, and all of us at the Trust are excited to see what amazing things are in store for the co-op class of 2020!

501(c)(3) EIN 23-2841453