Forest flows research programme

Forest Flows is a five-year research programme (September 2019 to September 2024) focussed on forest hydrology. Scion is leading the MBIE-supported programme.

The programme is developing methods to predict and optimise water use and supply in planted forests to answer the questions: Where is the water? Where is it going? And who gets to use it?

In 2023, preliminary results from the programme were released.

Tree water cycle


Understanding how water flows through the land, including planted forests is essential to make the best use of land and water while maintaining environmental health. New research is needed to replace outdated models and understand the complex processes of how water is distributed, used and circulated in forested catchments.

Scion team checking the Sensor Network Gateway at the Ashley Forest primary research site.

Research aims

The programme aims to create a biophysical model of forest hydrology that accurately predicts water storage and release for entire catchments, while also providing data on changes in water quality over time.

This programme will:

  1. Identify key forest hydrological processes by combining monitoring of soil-plant-atmosphere interactions with a range of targeted ground-based research over the long-term.
  2. Develop and use remote-sensing tools, to collect data that spans catchments and forests and can be linked to key forest hydrological processes.
  3. Create a model that predicts hydrological flow across a range of NZ planted forests.
  4. Create an decision making framework that provides the necessary information to optimise water use in planted forests.

We will achieve this through three Impact Areas (IAs):

Quantifying water processes within a forested catchment

By 2024, we will have identified and quantified the key above- and below-ground processes that govern water quantity and nutrient attenuation and transport within forested catchments. This new knowledge will provide the international scientific community with a fundamentally new understanding of the key processes governing planted-forest hydrology. The mechanistic processes will provide the key algorithms for our forest hydrology model to accurately simulate water quantity and nutrient attenuation in forests throughout New Zealand.

Spatially quantify forest water flux and storage at different scales with novel remote-sensing technology

By 2024, we will have developed a rapid, low cost, novel methodology to identify and quantify key hydrological processes spatially across a forest. This technology will enable:

  1. Accurate scaling of point measurements to the forest catchment scale;
  2. Accurate 3-dimensional modelling of key hydrological processes spatially across a forested catchment;
  3. Accurate modelling of water quantity and quality fluxes across multiple catchments and scales to the forest level.

These outputs will provide the key parameters and algorithms for the forest hydrology model to accurately calibrate and simulate water quantity and quality fluxes spatially in forests throughout New Zealand.

Develop and apply an assessment framework for the environmental, socioeconomic, and cultural impacts of planted forests on downstream water ecosystem services

By the end of 2024, we will have assessed the environmental, socioeconomic, and cultural impacts of upstream planted forests on downstream water users.

This will enable:

  1. Development of effective and efficient land-use regulations to promote positive impacts and mitigate negative impacts of planted forests on downstream water availability;
  2. Design of effective and efficient policy incentives (e.g., water compensation of forest owners using best forest practices) to promote the adoption of optimal-water-use forestry regimes.

Given the policy focus of this statement, our findings will be shared directly with key local stakeholders, policymakers, and relevant government agencies.

Deployed FlowLab wireless datalogger (left) and electronic dendrometer sensor (right on tree) measuring daily tree growth and water use.


Technology used in Forest Flows includes:

  • L- and P-Band synthetic aperture radar
  • Hyperspectral imaging
  • LiDAR
  • 18O stable isotope sampling
  • Continuous water nitrate measurements
  • Soil apparent electrical conductivity
  • Ground penetrating radar
  • Wireless meshed sensor networks providing real time spatial and temporal water quantity and quality data
  • Integrated data collection of water movement and storage throughout forested catchments through to streams and groundwater
  • Real time measurements of tree growth and water use for multiple species
  • Data fusion of terrestrial and remote sensing data


New Zealand-based collaborators include

International collaborators include

Related links


Dean Meason, Scientist, Plant Morphology and Physiology

Locations of the Forest Flows research sites with five primary and five secondary research sites.