A novel protocol for assessment of aboveground biomass in rangeland environments

C. Mundava, A.G.T. Schut, P. Helmholtz, R.G.H. Stovold, G. Donald, D.W. Lamb

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)

Abstract

Current methods to measure aboveground biomass (AGB) do not deliver adequate results in relation to the extent and spatial variability that characterise rangelands. An optimised protocol for the assessment ofAGBis presented that enables calibration and validation of remote-sensing imagery or plant growth models at suitable scales. The protocol combines a limited number of destructive samples with non-destructive measurements including normalised difference vegetation index (NDVI), canopy height and visual scores of AGB. A total of 19 sites were sampled four times during two growing seasons. Fresh and dry matter weights of dead and green components ofAGBwere recorded. Similarity of responses allowed grouping into Open plains sites dominated by annual grasses, Bunch grass sites dominated by perennial grasses and Spinifex (Triodia spp.) sites. Relationships between non-destructive measurements and AGB were evaluated with a simple linear regression per vegetation type. Multiple regression models were first used to identify outliers and then cross-validated using a 'Leave-One-Out' and 'Leave-Site-Out' (LSO) approach on datasets including and excluding the identified outliers. Combining all non-destructive measurements into one single regression model per vegetation type provided strong relationships for all seasons for total and green AGB (adjusted R2 values of 0.65-0.90) for datasets excluding outliers. The model provided accurate assessments of total AGB in heterogeneous environments for Bunch grass and Spinifex sites (LSO-Q2 values of 0.70-0.88), whereas assessment of green AGB was accurate for all vegetation types (LSO-Q2 values of 0.62-0.84). The protocol described can be applied at a range of scales while considerably reducing sampling time
Original languageEnglish
Pages (from-to)157-167
JournalThe Rangeland Journal
Volume37
Issue number2
DOIs
Publication statusPublished - 2015

Fingerprint

aboveground biomass
rangeland
rangelands
outlier
grass
vegetation types
vegetation type
grasses
Triodia
NDVI
growth models
multiple regression
remote sensing
dry matter
protocol
calibration
imagery
growing season
canopy
plant growth

Keywords

  • rising-plate-meter
  • dry tropical savanna
  • standing crop
  • herbage mass
  • grazing strategies
  • pasture biomass
  • vegetation
  • grassland
  • yield
  • management

Cite this

Mundava, C., Schut, A. G. T., Helmholtz, P., Stovold, R. G. H., Donald, G., & Lamb, D. W. (2015). A novel protocol for assessment of aboveground biomass in rangeland environments. The Rangeland Journal, 37(2), 157-167. https://doi.org/10.1071/RJ14072
Mundava, C. ; Schut, A.G.T. ; Helmholtz, P. ; Stovold, R.G.H. ; Donald, G. ; Lamb, D.W. / A novel protocol for assessment of aboveground biomass in rangeland environments. In: The Rangeland Journal. 2015 ; Vol. 37, No. 2. pp. 157-167.
@article{9cbf7c1682e149178648b1973960da40,
title = "A novel protocol for assessment of aboveground biomass in rangeland environments",
abstract = "Current methods to measure aboveground biomass (AGB) do not deliver adequate results in relation to the extent and spatial variability that characterise rangelands. An optimised protocol for the assessment ofAGBis presented that enables calibration and validation of remote-sensing imagery or plant growth models at suitable scales. The protocol combines a limited number of destructive samples with non-destructive measurements including normalised difference vegetation index (NDVI), canopy height and visual scores of AGB. A total of 19 sites were sampled four times during two growing seasons. Fresh and dry matter weights of dead and green components ofAGBwere recorded. Similarity of responses allowed grouping into Open plains sites dominated by annual grasses, Bunch grass sites dominated by perennial grasses and Spinifex (Triodia spp.) sites. Relationships between non-destructive measurements and AGB were evaluated with a simple linear regression per vegetation type. Multiple regression models were first used to identify outliers and then cross-validated using a 'Leave-One-Out' and 'Leave-Site-Out' (LSO) approach on datasets including and excluding the identified outliers. Combining all non-destructive measurements into one single regression model per vegetation type provided strong relationships for all seasons for total and green AGB (adjusted R2 values of 0.65-0.90) for datasets excluding outliers. The model provided accurate assessments of total AGB in heterogeneous environments for Bunch grass and Spinifex sites (LSO-Q2 values of 0.70-0.88), whereas assessment of green AGB was accurate for all vegetation types (LSO-Q2 values of 0.62-0.84). The protocol described can be applied at a range of scales while considerably reducing sampling time",
keywords = "rising-plate-meter, dry tropical savanna, standing crop, herbage mass, grazing strategies, pasture biomass, vegetation, grassland, yield, management",
author = "C. Mundava and A.G.T. Schut and P. Helmholtz and R.G.H. Stovold and G. Donald and D.W. Lamb",
year = "2015",
doi = "10.1071/RJ14072",
language = "English",
volume = "37",
pages = "157--167",
journal = "The Rangeland Journal",
issn = "1036-9872",
publisher = "CSIRO Publishing",
number = "2",

}

Mundava, C, Schut, AGT, Helmholtz, P, Stovold, RGH, Donald, G & Lamb, DW 2015, 'A novel protocol for assessment of aboveground biomass in rangeland environments' The Rangeland Journal, vol. 37, no. 2, pp. 157-167. https://doi.org/10.1071/RJ14072

A novel protocol for assessment of aboveground biomass in rangeland environments. / Mundava, C.; Schut, A.G.T.; Helmholtz, P.; Stovold, R.G.H.; Donald, G.; Lamb, D.W.

In: The Rangeland Journal, Vol. 37, No. 2, 2015, p. 157-167.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - A novel protocol for assessment of aboveground biomass in rangeland environments

AU - Mundava, C.

AU - Schut, A.G.T.

AU - Helmholtz, P.

AU - Stovold, R.G.H.

AU - Donald, G.

AU - Lamb, D.W.

PY - 2015

Y1 - 2015

N2 - Current methods to measure aboveground biomass (AGB) do not deliver adequate results in relation to the extent and spatial variability that characterise rangelands. An optimised protocol for the assessment ofAGBis presented that enables calibration and validation of remote-sensing imagery or plant growth models at suitable scales. The protocol combines a limited number of destructive samples with non-destructive measurements including normalised difference vegetation index (NDVI), canopy height and visual scores of AGB. A total of 19 sites were sampled four times during two growing seasons. Fresh and dry matter weights of dead and green components ofAGBwere recorded. Similarity of responses allowed grouping into Open plains sites dominated by annual grasses, Bunch grass sites dominated by perennial grasses and Spinifex (Triodia spp.) sites. Relationships between non-destructive measurements and AGB were evaluated with a simple linear regression per vegetation type. Multiple regression models were first used to identify outliers and then cross-validated using a 'Leave-One-Out' and 'Leave-Site-Out' (LSO) approach on datasets including and excluding the identified outliers. Combining all non-destructive measurements into one single regression model per vegetation type provided strong relationships for all seasons for total and green AGB (adjusted R2 values of 0.65-0.90) for datasets excluding outliers. The model provided accurate assessments of total AGB in heterogeneous environments for Bunch grass and Spinifex sites (LSO-Q2 values of 0.70-0.88), whereas assessment of green AGB was accurate for all vegetation types (LSO-Q2 values of 0.62-0.84). The protocol described can be applied at a range of scales while considerably reducing sampling time

AB - Current methods to measure aboveground biomass (AGB) do not deliver adequate results in relation to the extent and spatial variability that characterise rangelands. An optimised protocol for the assessment ofAGBis presented that enables calibration and validation of remote-sensing imagery or plant growth models at suitable scales. The protocol combines a limited number of destructive samples with non-destructive measurements including normalised difference vegetation index (NDVI), canopy height and visual scores of AGB. A total of 19 sites were sampled four times during two growing seasons. Fresh and dry matter weights of dead and green components ofAGBwere recorded. Similarity of responses allowed grouping into Open plains sites dominated by annual grasses, Bunch grass sites dominated by perennial grasses and Spinifex (Triodia spp.) sites. Relationships between non-destructive measurements and AGB were evaluated with a simple linear regression per vegetation type. Multiple regression models were first used to identify outliers and then cross-validated using a 'Leave-One-Out' and 'Leave-Site-Out' (LSO) approach on datasets including and excluding the identified outliers. Combining all non-destructive measurements into one single regression model per vegetation type provided strong relationships for all seasons for total and green AGB (adjusted R2 values of 0.65-0.90) for datasets excluding outliers. The model provided accurate assessments of total AGB in heterogeneous environments for Bunch grass and Spinifex sites (LSO-Q2 values of 0.70-0.88), whereas assessment of green AGB was accurate for all vegetation types (LSO-Q2 values of 0.62-0.84). The protocol described can be applied at a range of scales while considerably reducing sampling time

KW - rising-plate-meter

KW - dry tropical savanna

KW - standing crop

KW - herbage mass

KW - grazing strategies

KW - pasture biomass

KW - vegetation

KW - grassland

KW - yield

KW - management

U2 - 10.1071/RJ14072

DO - 10.1071/RJ14072

M3 - Article

VL - 37

SP - 157

EP - 167

JO - The Rangeland Journal

JF - The Rangeland Journal

SN - 1036-9872

IS - 2

ER -