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Vegetation biomass

  • Biodiversity

  • Compostion
  • Function
  • Structure


The direction of change in vegetation biomass provides different insights in ecosystem status, depending on the habitat. In grassland, an increase in vegetation biomass is often linked to declines in species richness, for example nutrient addition leads to grass dominance and a decline in species richness in chalk grassland (Willems et al. 1993). In woodland biomass can be used to track biotic (e.g. ash dieback) and physical (e.g. wind-throw disturbance) (Evans et al. 2019).

Experiments have found a positive relationship between species diversity and productivity, reflecting niche complementarity, resource acquisition and utilisation efficiency, and leading to higher aboveground biomass in more diverse systems (Liang et al. 2015, Tilman et al. 2014). However, in natural ecosystems vegetation biomass is not always positively associated with species diversity (van der Plas 2019).

At landscape and community scales, vegetation biomass is a measure of productivity, providing an insight into ecosystem function. Biomass recorded by species can be used to estimate species dominance and relative abundance.

Methodology summary

Collection of data on vegetation biomass can be carried out alongside data collection for Vegetation structure, Tree diversity, Seedling regeneration, and Tree Age.

Feeds into calculation of Relative abundance, Dominance-diversity curves, and Biomass (measure of abundance).

The UK National Forest Inventory (NFI) provides a standardised methodology to establish fixed area survey plots and record tree diameter at breast height (DBH) for all established trees (Forestry Commission 2020).

  • Forest is defined as having >20% canopy cover
  • 0.01 ha plots (5.64m radius) are established, the number of plots is determined by the size of the forest area
  • Within each plot DBH is recorded for all mature trees (DBH > 4 cm)

Allometric equations can be used to convert DBH measurements into biomass:

  • Zianis et al. 2005 Biomass and stem volume equations for tree species in Europe
  • Muukkonen and Mäkipää 2006 Biomass Equations for European Trees: Addendum

The NFI Survey Manual provides the methodology:

  • How to allocate plots – Chapter 12 Plot Assessments
  • Recording mature trees – Chapter 13 Tree Assessment Procedures

Other ecosystems

Herbaceous-dominated ecosystems (grassland, peatland, wetland, saltmarsh)

  • Destructive sampling of vegetation followed by drying can be used to estimate biomass
  • For grassland systems the Nutrient Network provides a method of assessing aboveground standing crop (see Core Sampling Methodology; Aboveground Standing Crop )
  • Samples should be collected at or just after the peak of the growing season
  • The aboveground standing crop in two 10 × 100 cm strips is clipped at ground level (the precise location should be recorded to avoid resampling in subsequent years), sampling effort should follow the guidance for assessing plant diversity, but avoid harvesting biomass within the plant diversity plots
  • The standing crop is sorted into 1. previous year’s dead material, 2. current year’s bryophytes, 3. current year’s graminoids (grasses, sedges, rushes), 4. current year’s legumes, 5. current year’s non-leguminous forbs, 6. current year’s woody growth
  • Vegetation is dried at 60 oC for 48 hour and weighed to the nearest 0.01 g
  • Estimation of productivity in grazed systems is complicated – in actively grazed systems temporary exclosures can be randomly placed for 1-2 weeks and samples collected from these and areas outside the exclosures to calculated the consumption level, which can be added to residual biomass at the end of the season to estimate overall aboveground productivity

Shrub-dominated ecosystems (heathland, scrub)

  • Estimation of productivity and biomass in shrub dominated systems requires a combination of destructive sampling, dimension analysis and extrapolation to unit area of landscape
  • Verra provide a methodology for estimating carbon stocks in non-tree pools.
  • Circular sampling frames (radius dependent on the heterogeneity of the vegetation)
  • All vegetation inside the frame is cut at the base and removed and weighed to give the wet mass
  • One representative subsample of the cut material is dried to determine the dry mass and the wet:dry ratio is calculated
  • The wet:dry ratio is used to estimate the aboveground biomass

Metric threshold or direction of change

The desired direction of change will depend on project objectives and the ecosystem type. In woody systems, particularly projects aiming to sequester carbon, an increase in vegetation biomass is often desirable. In grassland systems, increasing biomass over time may indicate nutrient enrichment and can be correlated with a loss of plant diversity.

Technological innovations

  • Most remote-sensing methods for estimating vegetation biomass focus on forest ecosystems, but there are also some examples of plant biomass estimation in wetlands (Lausch et al. 2016).
  • LiDAR sensors on airplanes or UAVs can be used to generate 3D canopy height models. Metrics such as canopy height, canopy cover, basal area, tree density and aboveground biomass can be derived from these (Jucker et al. 2023).
  • Spaceborne LiDAR data (captured by NASA GEDI) can also capture fine-scale variation
    in habitat 3D structure (Jucker et al. 2023).
  • Global equations linking tree height and crown size to aboveground biomass show promise for converting remote-sensed data to biomass (Jucker et al. 2017).
  • Terrestrial laser scanning addresses uncertainties in estimating aboveground biomass using allometric equations or Earth Observation methods (Demol et al. 2022, Calders et al. 2022).

  • Agricultural
  • Forest
  • Grassland
  • Heathland
  • Other
  • Peatland
  • Saltmarsh
  • Wetland


  • Community
  • Landscape
  • Population


  • Medium


  • Tier 2

Technical expertise

  • Low

Standardised methodology

  • Partial