Horn Farm Blog

For the Whole Stream: Riparian Buffers

Part 1: Upstream

This blog is the first installment of a new series called the Horn Farm Ecosystem. Through monthly articles, we’ll walk the land in writing: visiting the forests, regenerative fields, and ecological action sites of the Horn Farm Center to explain our stewardship work, uplift nature, and inspire love for the land. To learn more about the Horn Farm Ecosystem blog series, check out our February 17th, 2023 newsletter.


Whether you’re gathering for a class at our corn barn or whooshing by on Rt. 30, there’s a site at the Horn Farm Center that can’t be missed. Look east of the farmhouse, beyond the community garden plots, and you’ll see an expanse of tree tubes covering nearly 8 acres of land formerly dedicated to annual monocropping. Dotting the landscape, a twiggy menagerie: thousands of saplings planted between 2020 and this past summer eagerly waiting to outgrow their enclosures and bring large vegetation back to the land. In a time frame that seems tedious to us but a snap for nature, the likes of American hazelnut, sycamore, black and sandbar willow, various dogwoods, and more will cover this swath: a new forest born out of a willful overtaking. We’ve convened hundreds of community groups and volunteers over three years to facilitate this afforestation–or creation of a forest where there wasn’t one before–committing hundreds of hours and thousands of trees to just a fraction of our 186 acres, but why?

A sapling outgrowing its tree tube in the Horn Farm’s 8-acre riparian buffer, October 2022.

It’s of little contention that diverse trees (in tree-favoring environments) are a good thing, especially in a bioregion like ours, which now contends with a centuries-long legacy of agricultural clear-cutting alongside concerning air quality compared to the rest of the state. But there’s more to the story of the 15,000+ trees that have taken residence in our soils since we turned our attention to riparian health.

Venture out to the spot mentioned above and you’ll notice that the tree tube procession parallels a deep trench carving its way down the hillside. This is a human-made seasonal stream corridor, originally dug to drain water from bordering croplands. The eroded cut deposits into a natural creek—Kreutz Creek for York County readers—which then meanders east before emptying, like so many of our regional waterways, into the Susquehanna River. This downstream connection is the primary impetus for our undertaking. What we’re building is a riparian buffer.

What is a riparian buffer?

Picture: a lush array of grasses, shrubs, and trees snaking along both sides of a freshwater stream. This is a riparian buffer. The word “riparian,” from the Latin “streamside,” describes the area’s natural character: a transitional zone between the land and the waters of a river, lake, or stream, sometimes taking the shape of a wetland. “Buffer” designates the riparian area’s function in absorbing the impacts of adjacent land uses on the water. Across PA, riparian buffers have grown increasingly popular (and imperative) in agricultural fields, yards, commercial sites, and along roadsides: any place where the proximity of human activities to critical waterways is apparent and felt. Each riparian planting provides a host of benefits for water quality, soil health, and the surrounding ecology.

Simply put, the presence of trees, shrubs, and other vegetation along a waterway provides natural protection for the water and the life it carries.

Riparian buffers act like safety nets for streams, rivers, and lakes. Networks of tree roots help to keep soils in place, mimicking the porous earth of forests. Forested waterways are also better equipped to intercept sediment pollution, filter contaminants, and slow runoff that causes streambank erosion, all while providing favorable forage and habitat for birds, bats, insects, and aquatic life. Indeed, in the absence of riparian buffers, waterways become degraded. Impacts upstream quickly move downstream. Below are just a few of the ecological problems of exposed waterways:

  • Sedimentation: without vegetation to stop the runoff of solid particles and minerals, excess sediments enter the water and accumulate at the bottom, depleting aquatic oxygen levels and suffocating wildlife. 
  • Algal blooms: “nutrient pollution” from excess nitrogen and phosphorus leaching off croplands promotes a runaway “bloom” of algae on the water surface. This overabundance of algae depletes oxygen levels and blocks critical sunlight from reaching the stream floor. Nutrient leaching, especially of nitrogen, is a common side-effect of intensive agriculture that relies on industrial fertilizers. 
  • Streambank erosion: rapid runoff and unstable soils expedite the otherwise natural process of erosion along the stream edge, creating inhospitable conditions for fish and macroinvertebrates (aquatic insects) that depend on intact edges to spawn. This leads to population declines that can ripple up the food chain.
  • Temperature: without tree cover in the summer, unshaded waters overheat, making them uninhabitable for aquatic organisms. This is becoming increasingly common as our climate changes. 
  • Food availability: fish and aquatic insects require leaf litter that accumulates in the fall and winter to weather the cold seasons. Missing vegetation around the stream results in a lack of these vital nutrient sources, again destabilizing the base of the food chain. 
  • Carbon sequestration: trees and grasses are essential for balancing atmospheric carbon dioxide and absorbing the excess of greenhouse gasses emitted by human activities like the burning of fossil fuels. Simply put, missing vegetation is another missed opportunity to work proactively against climate change. 
  • Human value: Unstable streambanks, eroded soils, and a lack of biodiversity negatively affect our mental health and sense of belonging in the landscape.

While our regenerative farming approach does not apply chemical inputs like herbicides or synthetic fertilizers to the ground, we still see the impacts of a vacant landscape along our stream: drastic erosion, sediment deposits, and fast-moving water that, in 2021, partially flooded our riparian plantings.

Many locals will remember, as well, the destructive flash flooding of 2018 that affected much of York County, which was a major push for the Horn Farm Center’s turn to watershed health as an essential companion to healthy agriculture. Lastly, with runoff controlled by the return of a root web to the land, the farm will benefit from greater infiltration to better recharge our groundwater supply for community gardeners and other uses. Water security on the farm is becoming increasingly unpredictable as we endure drier, hotter summers each year. 

Ultimately, the newly planted 8 acre riparian buffer, which will grow to 10 acres this spring, will have an incredible impact on the farm and the ecosystem we’re a part of–from wildlife habitat to water security.

And like a drop of water in a stream, ecology ripples outwards. This is one of nature’s many teachings: how healthy elements positively affect relationships beyond the scope of what we can see. With this reality, our regenerative landscape is not just for us and our other-than-human neighbors, but for the health of waters, ecologies, and generations downstream.

Winter view of a Miyawaki mini-forest row adjacent to the stream edge (3/2023). The Miyawaki method for forest generation is another tactic we’re using beyond conventional tree spacing and tubing as we rewild the riparian area along our stream. An upcoming blog post will spotlight Miyawaki planting at the Horn Farm Center–stay tuned!

Click here to read For the Whole Stream Part 2: Downstream

Click here to read For the Whole Stream Part 3: Beyond the Stream


About the Author: Andrew Leahy

Growing up in the foothills of Ricketts Glen State Park, Andrew spent his early life in the embrace of Northeastern PA forests, sowing the seeds for his ongoing enchantment with the natural world and its stewardship. While studying English and Music Composition at Muhlenberg College, he gravitated toward nonprofit engagement as a work study student in the college’s Office of Community Engagement. Now, at the Horn Farm Center, Andrew manages social media, develops educational programs, coordinates volunteer events, and collaborates on marketing projects, large events, and organizational capacity-building. Through all of this, he is a dedicated student of the land, with a life’s mission of learning (and providing spaces for others to learn) about bioregional ecology, regenerative agriculture, permaculture, foraging, and locally-focused ways of living in reciprocal relationship with nature.

The Problem with Invasives

If you reduce the world far enough, you lose all perspective of an ending or a beginning, cold or heat, chaos or balance. All that’s left are building blocks – remnants of a supernova – compounds brought to earth on ancient comets. The ability to isolate and focus on elements of a system both enhances our understanding of atomic structures, and at the same time, blinds us to the bigger picture in which we find ourselves living. The same is true for so much of our understanding. Science can at once clarify age old problems, redefine lifeways, and change long held beliefs. So often, science mimics theology in fervor and resolute believers. A powerful scientific lens, and reductionist thinking, can also make it harder to see systems and the connections by which each element is attached to another. 

I have lived many lives in my forty years on this planet. I have read stacks of books piled high to the ceiling. I consume so many scientific papers it would seem I am working on a doctoral dissertation. I have done this in pursuit of purpose- explaining to myself what I am seeing, what I am feeling, and what I should do. I have dedicated my life to righting the wrongs my species seem hell bent on perpetrating.  Human-driven climate change, human-driven extinction, human-driven habitat destruction, war, pandemics, poverty – the list plays on like horror movie plotlines. 

Of Dreams and Wildness

One of the first plants I had a relationship with grew in an abandoned lot in New York City. Growing out of what seemed like gravel and concrete, this plant thrived defiantly among the rusty cars and human refuse.

My father would take me there to search for rabbits. We would pick up the roundest of rocks and fill our pockets with the perfect ammunition to fill a catapult’s leather pouch. Every careful step into our urban hunting ground filled my senses with the musky, earthy freshness of this silvery green plant. I learned almost twenty years later that this amazing pioneer species, which seemed impervious to the ammunition of extinction we build our society on, was mugwort- a dream enhancer. 

I dream often of that time, the wild feeling of pulling back taut rubber, the snap of the slingshot, the jump of the rabbit as the rock hit its target. The blood stained gravel so vividly contrasted the rusty metal fence that borders this “wildness” in which we found ourselves. So many of my early memories are of plants we now call invasive: non-native plants brought to this land for a myriad of reasons. 

Invasive Species

Humans have always moved plants and seeds well outside their native ranges; a quality that is one of our ecological niches, but it is not unique to us. Many animals move seeds, each filling a specialized role in cultivating life along the vastness of geography. Large animals trek seeds miles away from parent plants. Humans have taken our role to the extreme. We no longer only move seeds but whole plants, birds, insects, reptiles, amphibians, mammals, fungi, bacteria, viruses, and on and on. Over the last few thousand years we have rearranged the floral and faunal composition of the entire planet. Moving species and creating novel ecosystems that have no historical precedent. 

Today we find a world very different from our ancestors. In our forests, native black walnut trees act as trellises for Japanese vines. Birds pick berries off European privet. Spotted lanternflies suck sap from the native grapevine as it competes for sunlight and resources with a Japanese honeysuckle. Asian praying mantis eat ruby throated hummingbirds and they themselves are eaten by other native birds. European starlings fill the sky with synchronized movements, giving a glimpse into the past, shadowing the long-gone passenger pigeon that once darkened the sky.

This is what I see in the forests I tend. These new ecosystems flourish despite our species’ attempt to destroy them. These complex interactions flourish amidst the looming cultural idealism of native species superiority.

There is no doubt that native species have more connecting interactions with each other than in novel ecosystems. Relationships between pollinators and plants can stretch back millennia, while some novel interactions began mere months ago. 

Here at the farm we prioritize natives, and in most cases, we plant them exclusively. We do so not because of rigid ideas against non-native species, but with a deep understanding that nature is complex and mysterious – knowing that we don’t always know how one piece interacts with another.

What we do know is that we do not know enough to recreate an entire ecosystem. We work with the understanding of what we know, and what we don’t. Our culture has become the dogma of black and white, right and wrong, native and non-native. Binary thinking in a grey, complex, non-binary world. 

Curing Amnesia & Accepting What Is

The novelty of our predicament is mirrored in the novelty of our wild spaces and our amnesia of our place in nature. There is beauty in novel ecosystems. They are often the places where humanity can still interact with wildness without the rules created to protect wild spaces, which often keeps us separated from the wildness our psyche yearns for. 

If I could wave a wand and put all the plants and animals back to their native lands, I would pull the excess co2 from the atmosphere. I would remove the dams that choke our rivers, reforest the jungles, the taiga, the temperate hardwood forests. I would bring back the animals we have lost at the immense densities we once had.

The skies would be filled with life. The songs of birds would deafen us. The insects would dazzle us with their hum and flutter. The rivers would be teeming with life so dense you could almost walk across the water on the backs of fish. The oceans would be a symphony of whale songs and breach the surface across the globe. The air would smell of blossoms and decay, the cities would be wiped clean and forests and savannas would grow in their stead.

As much as I daydream about these things I realize it’s just that. A daydream. It takes me back to those summer days in New York City – mugwort wafting its scent as I stalk behind the rusted hulk of a Buick. The wind from the Verrazano, salty with the smell of the ocean, my mind one with the task, my heart beating wildly as I drew back the rubber. That same scene has played out for humans before we were homo sapiens. And there I realize is the keystone: the connection with place is the “magic wand.”

The love for the wild, whether an abandoned lot or a national park, is what drives us deeper into connection. 

Whether a rare native or a highly dispersive plant, the photosynthesis, the carbon sequestration, and the pollen, all act as a refuge for life that is quickly being paved, crushed, battered, and worst of all, forgotten.

I for one love all wild places, wild things and wild energies. Whether of this place or misplaced, each plant provides a service within the ecosystem. And while some prolific species can be challengingly aggressive, I have learned through listening, observation and humble stewardship that I can play a role in assisting nature in her infinite wisdom.

The greatest tragedy is not the spread of non-natives but the loss of relationship with place. The next time you venture out and try to see the world as wild and domestic, native and invasive, I challenge you to slow down and see the beautiful spectrum of life –  striving, evolving and playing its part – within novel ecosystems. 


About the Author – Wilson Alvarez

Wilson Alvarez is a certified permaculture designer, inventor, gardener, skilled tracker, bowyer, nature-awareness instructor, and writer from Lancaster, Pennsylvania.

For the past fourteen years, he has taught classes and workshops on bio-intensive agriculture, regenerative technology, foraging, hunting, trapping, tracking, and wilderness survival. Wilson has studied through the Wilderness Awareness School via the Kamana program, and he received his Permaculture Design Certificate via Susquehanna Permaculture. Wilson currently serves as the Woodland Steward at the Horn Farm Center in York, PA where he is implementing his research on biomimicry through the Reintegration Project. Learn more about Wilson’s work.

As We Are

Many years ago, well before I could comprehend what I was looking at, the forests around me seemed ageless. I could superimpose dinosaurs roaming amongst the trees I couldn’t yet identify. I could feel the pull of an ancient world. These small tracts of land I walked through seemed like primeval relics of a world unchanged since the beginning of time – but you don’t know what you don’t know, until you do.

The full burden of knowledge can crush an unsuspecting student of life. The weight of truth can be unbearable – leaving the cowardly to cower in the corner, oblivious to the mirage we call reality. I was exposed little by little, slowly inoculated with the full breadth of the ecological damage we face.

My childhood was an urban existence. The street trees and derelict lots were my Yellowstone. Pigeons and rats were my wildlife. When I moved to the countryside an acre of trees felt unending. I fell in love with the idea of wilderness instantly. Like a Disney story, it was love at first sight. Only the sight, the love, was for something completely different than what I first thought. Now I look at those same tracts of land, those small chunks of wild surrounded by civilization and I see it as it is:  a sad imposter to the wild spaces that once were, but also a glimmer of hope for the entire world. 

This slow composting of facts and figures, direct observations, and life lessons have formed a deep humus layer of wisdom, learned over and over by countless seekers of truth over eons and human lifetimes. The greatest lesson we learn as observers of wild places is this: We see the world not as it is, but as we are.

That hard truth speaks to the blindness we all have in our own perceptions. I have observed with my own eyes the same tract of land for 20 years. I have watched as a wall of green turned into red maples, box elders and willows. I have seen marks in the soil transform into fox tracks and deer hooves. I have witnessed lichen spread centimeter by centimeter. I have studied with wonder as the girth of a small spindly sycamore sapling grew to an 8 inch diameter.

And through my observation and growing awareness, I have come to recognize the turning of the seasons by a smell on the wind. I have seen the invisible connections become visible. I have begun to understand the connection to space and time: the fertile soil built of limestone bedrock, which once was the bottom of a shallow tropical sea. I have identified the anachronisms in our forest – a lesson born of injury, like so many of life’s deepest lessons. Just as the Mastodon discovered the sharpness of the honey locust, I too, became aware of her power as blood spilled from my own pricked finger.

Lately I have begun to hear the forest, not in words or visions, or even a way I can describe, but a symphony of all I have seen and witnessed. I can hear faint whispers of what the earth is communicating. And with all I have seen, and can see today, it is the ghosts of what once was that haunts me the most. The layers of connections that have been severed are unfathomably complex, like a great spider web that connects all things to all other things. 

What Was Lost

The crushing grief that comes with being haunted can either paralyze you into inaction or drive you to dig deeper: to listen harder, to pay attention to the minutiae. It has empowered me to listen to the land in new ways, to search for the missing pieces and become what was lost – the hands and claws, the hooves and paws that once roamed our forests in abundance.

We are facing multiple existential crises all at once: climate change, biodiversity loss and habitat destruction. The mere thought of things to come is enough to paralyze the most mentally sound. What can one human being do alone? What chance do we have of making a difference?

Then I remember this obscure fact: the small actions of millions of leaf cutter ants working in unison can cause disturbances in tropical forests, the size and scope of which only forest elephants can achieve. Small actions, one on top of another, like stacking bricks to build a wall, can become the foundation for another future we know is possible.

Fulcrum Points

We often run headfirst into tomorrow, ignorant to the hard won lessons of our ancestors: the taste of fertile soils, the feel of your heart beating out of your chest as you run towards your wounded prey, the sound of chanting and dancing in a language born out of the landscape itself, the faith that every action is pulling upon that great web to which all other actions are connected.

I am reminded that small doesn’t mean insignificant. It just means our actions must be more precise. We must find our fulcrum points where our efforts make the most difference, where the culmination of your existence regenerates the landscape in which you reside. Being part of a place is not just blood or historical rights. It is a state of being – one where the ego is composted to feed the ecological systems we rely on for our very existence. 

Consider starting small. Find a spot you can go everyday and sit. No agenda, no journals, no cellphone apps required – just sit and observe quietly. The power of this exercise is not in what you will see but what you will ask: “What is that? Who is singing that beautiful song? Where is the wind coming from? Why does the snow stay in this spot for longer? How does the squirrel climb so fast?

The power in questions is that they lead to more questions – and deeper observations. Until one day the invisible, the connections between the pieces, are as visible as the oak you rest your back on as you sit and watch the seasons change.

Another simple interaction is collecting refuse left in our wild spaces. Often a piece of litter can pull you out of a daydream. Like a text message it rips you away from a state of BEING into a state of thinking, planning, complaining. Simply by picking up trash, we can create a more beautiful world, where our minds can roam with the wild creatures around us.

So go forth into the cracks and crevices – leave the paths for the visitors. Wild creatures use the brambles for protection, they listen to the bird songs to warn them of danger and they dart quickly past the pavement – past the houses and manicured landscapes – into the unkempt. They listen to their gut and instinct as much as their senses. For in wild spaces the ego is destroyed. Slowly but surely, you will remember that you too are a part of the ecosystem – and in that, we come back home.


Wilson Alvarez - Woodland Steward
Wilson Alvarez, Woodland Steward at the Horn Farm Center

About the Author – Wilson Alvarez

Wilson Alvarez is a certified permaculture designer, inventor, gardener, skilled tracker, bowyer, nature-awareness instructor, and writer from Lancaster, Pennsylvania.

For the past fourteen years, he has taught classes and workshops on bio-intensive agriculture, regenerative technology, foraging, hunting, trapping, tracking, and wilderness survival. Wilson has studied through the Wilderness Awareness School via the Kamana program, and he received his Permaculture Design Certificate via Susquehanna Permaculture. Wilson currently serves as the Woodland Steward at the Horn Farm Center in York, PA where he is implementing his research on biomimicry through the Reintegration Project. Learn more about Wilson’s work.