Opinion: Add trees for a future water-friendly landscape
The time is now to put trees at the heart of land management policy and reap all the benefits they provide, The Woodland Trust's public affairs manager - Wales, Jerry Langford, writes
A vibrant and healthy environment is the basis of our prosperity and wellbeing, and this is equally true for our freshwater, terrestrial and marine environments.
There is an opportunity now to break with past mistakes and ensure that future land management policy puts this aim squarely at the centre of decision-making – for example, changing the pervasive political, commercial and public culture that considers pollution to be an acceptable consequence of economic activity.
Why are trees important to this? In a general sense, trees provide many of our essential requirements – clean air, water, soil, food, fuel and building materials. They substantially affect how water interacts with the landscape and are tools to manage the water environment.
Tree roots penetrate deeply and extensively and in doing so aid deep infiltration of rain water, arresting surface flow and sediment movement. Tree canopies stand tall and intercept moisture and pollutants and ameliorate the local environment by providing shade and shelter.
Combining an understanding of these basic processes with a land owner’s intimate knowledge of their terrain and soils allows trees to be placed and managed in ways that help maintain water quality, slow flood peaks and provide an optimum streamside environment. The interception of pollutants by tree canopies can present challenges but once understood this can be exploited as part of an integrated catchment scale approach. It would be better of course to reduce the pollution in the first place.
Integrated into farming systems, trees not only help to manage water and air pollution but can prevent soil erosion and boost soil sustainability through support of microorganisms and addition of nutrients. They help with shelter for livestock, crop pollination, integrated pest management and product diversification. Tree belts that run mid-slope and down slope field edges can be effective in increasing water infiltration, reducing and slowing runoff and intercepting nutrient and sediment. Studies at Pontbren in mid-Wales found that water infiltration increased by 60 times within 5m of tree shelter belts after just three years of planting.
Forests can be very good for water quality and flood amelioration, but how they are designed and managed matters greatly. The most water-friendly forests will be of mixed composition and structure and managed to achieve some continuous canopy cover, maintain ground vegetation and open habitat. Ancient woodland and peatland features would be protected and restored and natural water features protected by riparian zones of native habitats. Roads and drainage systems will be designed to minimise impact on natural watercourses.
In towns and cities, trees provide an essential component to the green infrastructure that enables sustainable urban drainage (Suds) and captures pollutants in leaf litter and the soil. Extensive guidance on using such green infrastructure is now available and proposed new planning guidance will require planning authorities in Wales to undertake green infrastructure assessments.
For too long, our approach to woods and trees has been fragmented. The operation of the Common Agricultural Policy, and its complex regulatory and support framework, has effectively split the countryside away from our towns and cities, separated land managers into farmers and non-farmers, and disconnected farming and forestry from impacts on the water environment. There is more and more evidence that trees and woods can be a heavyweight contributor to solving the issues we face, but they are too often excluded from consideration.
In our publication Sustainable Land Management, the Woodland Trust sets out its belief that protecting basic resources such as soil, water and biodiversity should be a core regulatory requirement. Beyond that, public money should pay for public goods – specific interventions for clear public benefit. For example, we call for funding for tree belts for soil and water protection and upland planting for flood prevention. This needs local knowledge, design and delivery, reproduced across whole landscapes to achieve real change.
The resultant water-friendly landscapes would be complex, with a diverse and heterogeneous scatter of tree cover and networks of habitat including riparian zones protecting all lakes and watercourses. Our forests would be structurally diverse and interwoven with connected networks of riparian and other wild and ancient habitats. In towns and cities there would be at least 20 per cent tree cover, matching what is already achieved by Wales’ best Tree Towns.
Jerry Langford is speaking on the subject of how land management arrangements will function post-Brexit at the WWT Wales Water Conference, which takes place in Cardiff on 17 May. For more information, visit: https://event.wwtonline.co.uk/wales/
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