Guest Contributor: Nick May, Senior Project Manager, Ecosulis, U.K.

The role of trees in riparian areas is an important topic, particularly in an ever-changing world where the scale of impacts from climate change seems to be worsening by the day.

Having been in the tree industry for ten years, I have managed many of Ecosulis’s largest contracts during this time, including numerous wetland and woodland creation projects.

I am not an advocate of planting trees merely for the sake of it. This is especially true in areas where there may be better alternatives, such as reconnecting watercourses with their floodplains, creating meadows, or allowing the land to rewild naturally. However, planting certain trees in riparian areas certainly has its place — the challenge lies in determining which trees, how many, and where to plant them.

Shrub Planting on Dam Shoulder/Photo Nick May
Shrub Planting on Dam Shoulder/Photo Nick May

These are the questions I typically ask clients who believe that tree planting is the panacea for saving the planet.. A hectare of wetland absorbs up to three times more carbon than a hectare of woodland or forest, and it also quickly provides a more biodiverse habitat. There are times and places where trees are particularly beneficial.

Riverbanks are an excellent example. Worldwide, certain trees naturally germinate and establish themselves. In the U.K., the Salix is renowned for its unparalleled efficacy in stabilizing riverbanks, as well as its importance in British culture — Salix is indispensable in the manufacture of cricket bats. Other tree species are available for establishing, notably Alnus.

But trees do more than just fortify riverbanks. They help bind soils, preventing topsoil runoff, their shade reduces water evaporation and cool pools for fish to spawn, and they offer shelter for humans and animals alike. Trees also diminish the amount of rainfall reaching the ground. Their roots add structure to soils while absorbing excess nutrients, an important function as there isn’t a watercourse in the U.K. that isn’t affected by over-eutrophication. Trees are also aesthetically pleasing and are ever present indicators of the changing seasons.

So, what’s the way forward? We unquestionably need trees, but it’s critical to plant the right tree in the right place. To illustrate this, consider a couple of sites I have worked on: one in Sussex and another in Bristol. In Sussex, the trees are planted away from the watercourse, partly at the landowner’s request for future use and partly to utilise their roots in stabilising soils at the tops of steep slopes and on the shoulders of a man-made clay dam.

Drone Footage of Watercress Farm, Bristol/Photo Ecosulis

In contrast, the Bristol site, developed in 2023, involved re-meandering the Land Yeo River, a watercourse historically straightened and dredged. The landowner of Watercress Farm planted Salix trees in erosion-prone areas, along the newly created channel. The Salix’s rapid root growth is instrumental in holding the banks together while the wetland and river develop.

The land where the channel has been created has been left to rewild for over three years, as part of the estate’s effort to restore the pre-agricultural ecosystem. The previously intensively farmed land, once rooted through by wild pigs in winter due to the absence of roots and food sources, is now showing early signs of ecological recovery, with brambles emerging alongside the new watercourse. The addition of Salix bareroot whips will further enhance soil development, hopefully restoring it to its original state.

I view trees as one of many tools in our nature repair toolkit. As the world continues to evolve and weather patterns become more unpredictable, we as a species must intensify our efforts. This could involve building wetlands, restoring forests and woodlands, allowing nature to re-establish itself, or actively engaging in rewilding to restore natural processes. We have no choice but to act, and to act swiftly.

Woody Debris and Salix Planting at Watercress Farm/Photo Joel Green