At this year’s World Water Week (2025), join us in reframing the narrative – moving beyond the view of forests and agriculture as competing land uses, and toward recognising their vital role in building water- and climate-resilient agricultural systems.
As the world faces rising temperatures, water stress, and growing food demand, it’s time we see forests for what they truly are: critical engines of the Earth, circulating water, sustaining agricultural productivity, moderating climates, nourishing life and protecting biodiversity.
Overlooking their vital functions will come at a high cost for the entire planet, particularly in regions where agriculture depends predominantly on rainfall and the climatic stability forests help provide.
Trees and Forests: The Overlooked Engine of Our Global Water and Food System
As climate change accelerates and global water stress intensifies, scientists and policymakers face an urgent need to rethink the management of land and water resources, fundamental to global agricultural production. Agriculture – our lifeline for food security – is increasingly threatened by drought, floods, and erratic rainfall. Yet, trees and forests, a crucial piece of food system transformation, remain undervalued and underutilised.
Forests and trees can influence rainfall patterns, stabilise streamflows, improve water quality, reduce surface runoff, accelerate groundwater recharge and increase soil moisture. These functions are critical not only for ecosystems, but for the stability of agricultural production and water supply systems. From mountaintop cloud forests to trees scattered across African savannah farms, forests and trees play a critical role in stabilising local climates and sustaining the quantity, quality, and timing of freshwater flows that underpin food production. Yet, their benefits remain largely invisible in national water strategies, agricultural frameworks, and land-use planning. This oversight is not only a missed opportunity – it’s a policy risk.
Empirical Cases: Trees and Forests are Nature’s Water and Climate Regulators
Forests and trees provide cooling benefits through evapotranspiration and shape rainfall patterns locally and hundreds of kilometres downwind. They also act as buffers, absorbing excess rain during storms and releasing moisture slowly during droughts. Evidence from regions such as the Sahel and southern Africa underscores the importance of these contributions.
In Burkina Faso, certain trees in agroforestry parklands enhance groundwater recharge by up to six times compared to treeless land. They also have the ability to pull water via their roots from deep below ground and “share” it in topsoil layers with crops – a natural form of bio-irrigation creating natural buffers against drought and heatwaves. FAO’s ongoing work in Zambia’s forested headwaters of the Zambezi River indicates how sustainable forest management can increase water availability, reduce erosion, and strengthen resilience. For communities dependent on agriculture, fishing, and livestock, this translates directly into greater resilience and food security.
Correct Policy Imbalances: Blue and Green Water Deserve Equal Attention
Policy and economic assessments often focus on “blue water” – the water in rivers, lakes, and aquifers – while overlooking “green water,” the soil moisture and evapotranspiration that sustains 80% of the world’s crops and is largely shaped by the intricate layers of plants growing above the ground. For instance, many land-use models rarely factor in the hydrological services of forests and trees and instead favour short-term agricultural expansion over long-term hydrological stability. Hence, green water is largely ignored in national water planning, leading to underrepresentation of forest-water interactions in restoration, irrigation, and climate resilience programs. This blind spot reinforces short-sighted choices such as deforestation and threatens long-term water security, agricultural productivity, and climate resilience.
To fully realise the benefits of trees and forests, policymakers must prioritise the following actions:
- Integrate Forests into Water and Agricultural Policy
- Embed forest-water functions into national water, agriculture, and climate strategies, including Nationally Determined Contributions (NDCs).
- Promote Landscape-Level Water Governance
- Facilitate integrated land and water management through land-use planning and strengthen interministerial coordination across forestry, agriculture, environment, and water sectors.
- Invest in Monitoring and Evaluating Water Flows
- Improve data and decision-support on blue and green water flows, evapotranspiration rates, and the hydrological impacts of land-use change.
- Support Local Land Stewards
- Support communities managing forest-agriculture mosaics through secure land tenure, technical assistance, and incentive programs.
Mobilising for Change
As climate variability intensifies, the cost of inaction will be felt in lower crop yields, erratic water supplies, and reduced resilience for communities and ecosystems. With smart, evidence-based policies, forests can become a cornerstone of climate-resilient agriculture and water security.
The scientific evidence is clear and presented in a forthcoming multi-institutional report – led by the FAO and SEI, with contributions from SIWI, The Nature Conservancy (TNC), and SLU – which outlines the multiple benefits that forests and trees provide for agriculture. What’s needed now is bold political will and coordinated action to scale positive forest-water-agriculture interactions.