Biomass estimation models for Acacia saligna trees in restored landscapes

Hagazi N, Kebede M, Mokria M, Birhane E, Gebrekirstos A, Bräuning A (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Environmental Research Communications Institute of Physics Publishing (IOP)

Book Volume: 5

Article Number: 125007

Journal Issue: 12

DOI: 10.1088/2515-7620/ad12e1

Abstract

Acacia saligna, originating from Australia, is a naturalized multipurpose tree species widely grown to restore degraded lands of Africa. The contribution of A. saligna in biomass restoration can be quantified using a precise estimation of tree biomass carbon. This study developed species-specific allometric models and evaluated the spatial variation of tree biomass across restored areas in exclosures and open grazing landscapes. These models could play a considerable role in the monitoring of carbon dynamics across A. saligna planation dominated areas. We harvested, excavated, and weighed twenty-one sample trees representing different size classes to develop allometric models for the estimation of aboveground (AGB), belowground (BGB) and total tree (TB) biomass. The average dry-to-fresh mass ratio and the root-to-shoot ratio was 0.47 (±0.13) and 0.28 (±0.14), respectively. Tree biomass significantly correlated with diameter at breast height (r = 0.93; P < 0.001), diameter at stump height (r = 0.88, P < 0.001) and tree height (r = 0.56, P < 0.05). Our best biomass estimation models explained 86%, 82% and 87% of variations in AGB, BGB, and TB, respectively. Models using DSH and DSH & H explained 70%-78% of the variation in AGB, BGB, and TB. Estimated C-stock showed a significant relationship with stem density (R 2 = 0.91, P < 0.01). Estimated TB varied between 1.5-18 Mg ha−1 on grazed land and exclosures. Estimated C-stocks in the exclosure exceeded the estimated C-stock in the open grazing land by ∼60%. This implies that with proper management practices and enrichment planting A. saligna significantly contributes to increasing carbon accumulation on degraded landscapes, playing a key role in climate change mitigation efforts while improving land productivity.

Authors with CRIS profile

Achim Bräuning Lehrstuhl für Geographie (Physische Geographie)

Involved external institutions

International Livestock Research Institute Ethiopia (ILRI) ET Ethiopia (ET) Tigray Agricultural Research Institute (TARI) / ኢንስቲትዩት ምርምር ሕርሻ ትግራይ ET Ethiopia (ET) Norwegian University of Life Sciences (NMBU) NO Norway (NO) World Agroforestry Centre KE Kenya (KE)

How to cite

APA:

Hagazi, N., Kebede, M., Mokria, M., Birhane, E., Gebrekirstos, A., & Bräuning, A. (2023). Biomass estimation models for Acacia saligna trees in restored landscapes. Environmental Research Communications, 5(12). https://doi.org/10.1088/2515-7620/ad12e1

MLA:

Hagazi, Niguse, et al. "Biomass estimation models for Acacia saligna trees in restored landscapes." Environmental Research Communications 5.12 (2023).

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