A global map of root biomass across the world's forests

Abstract. As a key component of the Earth system, root plays the key role in linking Earth's lithosphere, hydrosphere, biosphere, and atmosphere. Here we combine 10307 field measurements of forest root biomass worldwide with global observations of forest structure, climatic conditions, topography, land management and soil characteristics to derive a spatially explicit global high-resolution (~1 km) root biomass dataset, including fine and coarse roots. In total, 142 ± 25 (95 % CI) Pg of live dry matter biomass is stored below-ground, representing a global average root:shoot biomass ratio of 0.25 ± 0.10. Our estimations of total root biomass in tropical, temperate and boreal forests are 44–226 % smaller than earlier studies (Jackson et al., 1997; Robinson, 2007; Saugier et al., 2001). The smaller estimation is attributable to the updated forest area, spatially explicit above-ground biomass density used to predict the patterns of root biomass, new root measurements and upscaling methodology. We show specifically that the root shoot allometry is one underlying driver that leads to methodological overestimation of root biomass in previous estimations. Raw datasets and global maps generated in this study are deposited at the open access repository Figshare (https://figshare.com/articles/Supporting_data_and_code_for_A_global_map_of_root_biomass_across_the_world_s_forests/ 12199637).

Download Full-text

A global map of root biomass across the world’s forests

10.1101/2020.01.14.906883 ◽

2020 ◽

Author(s):

Yuanyuan Huang ◽

Phillipe Ciais ◽

Maurizio Santoro ◽

David Makowski ◽

Jerome Chave ◽

...

Keyword(s):

Boreal Forests ◽

Root Biomass ◽

Dry Matter ◽

Field Measurements ◽

Climatic Conditions ◽

Spatially Explicit ◽

Biomass Density ◽

Coarse Roots ◽

Below Ground ◽

Shoot Allometry

Abstract (150 words limits)Root plays a key role in plant growth and functioning. Here we combine 10307 field measurements of forest root biomass worldwide with global observations of forest structure, climatic conditions, topography, land management and soil characteristics to derive a spatially-explicit global high-resolution (~ 1km) root biomass dataset, including fine and coarse roots. In total, 142 ± 32 Pg of live dry matter biomass is stored below-ground, that is a global average root:shoot biomass ratio of 0.25 ± 0.10. Our estimations of total root biomass in tropical, temperate and boreal forests are 44-226% smaller than earlier studies1–3. The smaller estimation is attributable to the updated forest area, spatially explicit above-ground biomass density used to predict the patterns of root biomass, new root measurements and upscaling methodology. We show specifically that the root shoot allometry is one underlying driver that leads to methodological overestimation of root biomass in previous estimations.

Download Full-text

A global map of root biomass across the world's forests

Earth System Science Data ◽

10.5194/essd-13-4263-2021 ◽

2021 ◽

Vol 13 (9) ◽

pp. 4263-4274

Author(s):

Yuanyuan Huang ◽

Phillipe Ciais ◽

Maurizio Santoro ◽

David Makowski ◽

Jerome Chave ◽

...

Keyword(s):

Boreal Forests ◽

Root Biomass ◽

Field Measurements ◽

Climatic Conditions ◽

Shoot Biomass ◽

Spatially Explicit ◽

Biomass Density ◽

Coarse Roots ◽

Recent Estimate ◽

Shoot Allometry

Abstract. As a key component of the Earth system, roots play a key role in linking Earth's lithosphere, hydrosphere, biosphere and atmosphere. Here we combine 10 307 field measurements of forest root biomass worldwide with global observations of forest structure, climatic conditions, topography, land management and soil characteristics to derive a spatially explicit global high-resolution (∼ 1 km) root biomass dataset, including fine and coarse roots. In total, 142 ± 25 (95 % CI) Pg of live dry-matter biomass is stored belowground, representing a global average root : shoot biomass ratio of 0.25 ± 0.10. Earlier studies (Jackson et al., 1997; Robinson, 2007; Saugier et al., 2001) are 44 %–226 % larger than our estimations of the total root biomass in tropical, temperate and boreal forests. The total global forest root biomass from a recent estimate (Spawn et al., 2020) is 24 % larger than this study. The smaller estimation from this study is attributable to the updated forest area, spatially explicit aboveground biomass density used to predict the patterns of root biomass, new root measurements and the upscaling methodology. We show specifically that the root shoot allometry is one underlying driver that has led to methodological overestimation of root biomass in previous estimations. Raw datasets and global maps generated in this study are deposited at the open-access repository Figshare (https://doi.org/10.6084/m9.figshare.12199637.v1; Huang et al., 2020).

Download Full-text

Net primary productivity and below-ground crop residue inputs for root crops: Potato (Solanum tuberosum L.) and sugar beet (Beta vulgaris L.)

Canadian Journal of Soil Science ◽

10.4141/cjss-2014-091 ◽

2015 ◽

Vol 95 (2) ◽

pp. 87-93 ◽

Cited By ~ 13

Author(s):

Martin A. Bolinder ◽

Thomas Kätterer ◽

Christopher Poeplau ◽

Gunnar Börjesson ◽

Leon E. Parent

Keyword(s):

Sugar Beet ◽

Primary Productivity ◽

Root Biomass ◽

Crop Residue ◽

Crop Residues ◽

Net Primary Productivity ◽

Solanum Tuberosum L ◽

Field Measurements ◽

Root Crops ◽

Below Ground

Bolinder, M. A., Kätterer, T., Poeplau, C., Börjesson, G. and Parent, L. E. 2015. Net primary productivity and below-ground crop residue inputs for root crops: Potato (Solanum tuberosum L.) and sugar beet (Beta vulgaris L.). Can. J. Soil Sci. 95: 87–93. Root crops are significant in agro-ecosystems of temperate climates. However, the amounts of crop residues for these crop types are not well documented and they need to be accounted for in the modeling of soil organic carbon dynamics. Our objective was to review field measurements of root biomass left in the soil as crop residues at harvest for potato and sugar beet. We considered estimates for crop residue inputs as root biomass presented in the literature and some unpublished results. Our analysis showed that compared to, for example, cereals, the contribution of below-ground net primary productivity (NPP) to crop residues is at least two to three times lower for root crops. Indeed, the field measurements indicated that root biomass for topsoils only represents on average 25 to 30 g dry matter (DM) m−2 yr−1. Other estimates, albeit variable and region-specific, tended to be higher. We suggest relative plant DM allocation coefficients for agronomic yield (RP), above-ground biomass (RS) and root biomass (RR) components, expressed as a proportion of total NPP. These coefficients, representative for temperate climates (0.739:0.236:0.025 for potato and 0.626:0.357:0.017 for sugar beet), should be useful in the modeling of agro-ecosystems that include root crops.

Download Full-text

Estimation of root biomass based on excavation of individual root systems in a primary dipterocarp forest in Pasoh Forest Reserve, Peninsular Malaysia

Journal of Tropical Ecology ◽

10.1017/s0266467410000040 ◽

2010 ◽

Vol 26 (3) ◽

pp. 271-284 ◽

Cited By ~ 75

Author(s):

Kaoru Niiyama ◽

Takuya Kajimoto ◽

Yojiro Matsuura ◽

Tamon Yamashita ◽

Naoko Matsuo ◽

...

Keyword(s):

Root Biomass ◽

Root Systems ◽

Allometric Equation ◽

Peninsular Malaysia ◽

Carbon Stocks ◽

Coarse Roots ◽

Forest Reserve ◽

Dipterocarp Forest ◽

Below Ground ◽

Individual Root

Abstract:Precise estimation of root biomass is important for understanding carbon stocks and dynamics in tropical rain forests. However, limited information is available on individual root masses, especially large trees. We excavated 121 root systems of various species (78) and sizes (up to 116 cm in dbh), and estimated both above- and below-ground biomass in a lowland primary dipterocarp forest in the Pasoh Forest Reserve, Peninsular Malaysia. A tree census was conducted in four research plots (each 0.2 ha) and stand-level biomass was estimated. We examined relationships between tree size parameters and masses of coarse roots (roots ≥5 mm in diameter) and derived a dbh-based allometric equation. The amounts of coarse roots that were lost during excavation were corrected. Coarse-root biomass before and after correction for lost roots was estimated to be 63.8 and 82.7 Mg ha−1, indicating that significant amounts of roots (23%) were lost during the sampling. We also estimated the biomass of small root (<5 mm) by applying pipe-model theory. The estimate, 13.3 Mg ha−1, was similar to another estimate of small roots, 16.4 Mg ha−1, which was obtained directly by the soil-pit sampling method. Total below-ground (BGB) and above-ground biomass (AGB) was estimated to be 95.9 and 536 Mg ha−1, respectively. The biomass-partitioning ratio (BGB/AGB) was about 0.18. In conclusion, the dbh-based allometric equation for coarse roots developed in this study, which kept good linearity even including the data of larger trees, might be useful for evaluating below-ground carbon stocks in other stands of similar forest (old-growth dipterocarp) in South-East Asia.

Download Full-text

Carbon and nutrient stocks in roots of forests at different altitudes in the Ecuadorian Andes

Journal of Tropical Ecology ◽

10.1017/s0266467407004002 ◽

2007 ◽

Vol 23 (3) ◽

pp. 319-328 ◽

Cited By ~ 23

Author(s):

Nathalie Soethe ◽

Johannes Lehmann ◽

Christof Engels

Keyword(s):

Fine Roots ◽

Root Biomass ◽

Plant Biomass ◽

Coarse Roots ◽

Nutrient Analysis ◽

Tropical Montane Forests ◽

Nutrient Stocks ◽

Below Ground ◽

Total Plant Biomass ◽

Total Plant

Carbon and nutrient stocks in below-ground biomass have rarely been investigated in tropical montane forests. In the present study, the amounts of carbon, nitrogen, phosphorus, sulphur, potassium, calcium and magnesium in root biomass were determined by soil coring and nutrient analysis in forests at three altitudes (1900, 2400 and 3000 m) in the Ecuadorian Andes. Root biomass increased markedly from 2.8 kg m−2 at 1900 m and 4.0 kg m−2 at 2400 to 6.8 kg m−2 at 3000 m. The contribution of coarse roots (> 2 mm in diameter) to total root biomass increased from about 70% at 1900 m to about 80% at higher altitudes. In fine roots (≤ 2 mm in diameter), concentrations of nutrients except calcium markedly decreased with altitude. Therefore, the nutrient stocks in fine roots were similar at 1900 m and 3000 m for nitrogen and sulphur, and were even lower at higher altitudes for phosphorus, potassium and magnesium. In coarse roots of Graffenrieda emarginata concentrations of nutrients were substantially lower than in fine roots, and were little affected by altitude. The data suggest that the importance of coarse roots for long-term carbon and nutrient accumulation in total plant biomass increases with increasing altitude.

Download Full-text

The vertical and horizontal distribution of roots in northern hardwood stands of varying age

Canadian Journal of Forest Research ◽

10.1139/x05-254 ◽

2006 ◽

Vol 36 (2) ◽

pp. 450-459 ◽

Cited By ~ 67

Author(s):

Ruth D Yanai ◽

Byung B Park ◽

Steven P Hamburg

Keyword(s):

Root Biomass ◽

Fine Root ◽

Forest Type ◽

Soil Depth ◽

Horizontal Distribution ◽

Biomass Density ◽

Coarse Roots ◽

Northern Hardwood ◽

Clear Cutting ◽

Distribution Of Roots

Coring methods cannot reveal the distribution of roots with depth in rocky soil, and fine roots are typically sampled without regard to the location of trees. We used quantitative soil pits to describe rooting patterns with soil depth and distance to trees in northern hardwood stands. We sited three 0.5 m2 quantitative soil pits in each of three young (1927 years) and three older (5669 years) stands developed after clear-cutting. Live roots were divided into diameter classes delimited at 0.5, 1, 2, 5, 10, 20, and 100 mm; dead roots were not distinguished by size. Mean total live-root biomass was 2900 ± 500 g·m2 in older stands and 1500 ± 400 g·m2 in young stands. The root mass in the 220 mm class was 2.7 times greater in the older stands (p = 0.03); fine-root (<2 mm) biomass was 1.5 times greater (p = 0.12), suggesting that fine-root biomass continues to increase past the age of canopy closure in this forest type. Root biomass density declined with soil depth, with the finest roots (<0.5 mm) declining most steeply; roots were found at low densities well into the C horizon. We analyzed root biomass density as a function of the influence of nearby trees (represented as the sum of basal area divided by the distance from the pit) and found that fine as well as coarse roots reflected this influence. In systems where this is the case, root measurements should be made with attention to patterns of tree distribution.

Download Full-text

Drone-Based Remote Sensing for Research on Wind Erosion in Drylands: Possible Applications

Remote Sensing ◽

10.3390/rs13020283 ◽

2021 ◽

Vol 13 (2) ◽

pp. 283

Author(s):

Junzhe Zhang ◽

Wei Guo ◽

Bo Zhou ◽

Gregory S. Okin

Keyword(s):

Remote Sensing ◽

Wind Erosion ◽

Field Measurements ◽

Spatially Explicit ◽

Surface Model ◽

High Resolution Imagery ◽

Soil Elevation ◽

3D Photogrammetry ◽

Using Data ◽

Sample Set

With rapid innovations in drone, camera, and 3D photogrammetry, drone-based remote sensing can accurately and efficiently provide ultra-high resolution imagery and digital surface model (DSM) at a landscape scale. Several studies have been conducted using drone-based remote sensing to quantitatively assess the impacts of wind erosion on the vegetation communities and landforms in drylands. In this study, first, five difficulties in conducting wind erosion research through data collection from fieldwork are summarized: insufficient samples, spatial displacement with auxiliary datasets, missing volumetric information, a unidirectional view, and spatially inexplicit input. Then, five possible applications—to provide a reliable and valid sample set, to mitigate the spatial offset, to monitor soil elevation change, to evaluate the directional property of land cover, and to make spatially explicit input for ecological models—of drone-based remote sensing products are suggested. To sum up, drone-based remote sensing has become a useful method to research wind erosion in drylands, and can solve the issues caused by using data collected from fieldwork. For wind erosion research in drylands, we suggest that a drone-based remote sensing product should be used as a complement to field measurements.

Download Full-text

Are Wildfires a Threat to Fungi in European Pinus Forests? A Case Study of Boreal and Mediterranean Forests

Forests ◽

10.3390/f10040309 ◽

2019 ◽

Vol 10 (4) ◽

pp. 309 ◽

Cited By ~ 3

Author(s):

Iván Franco-Manchón ◽

Kauko Salo ◽

Juan Oria-de-Rueda ◽

José Bonet ◽

Pablo Martín-Pinto

Keyword(s):

Boreal Forests ◽

Fungal Diversity ◽

Community Dynamics ◽

Forest Products ◽

Climatic Conditions ◽

Fungal Communities ◽

Mediterranean Forests ◽

Natural Forests ◽

Edible Fungi ◽

Pinus Species

Natural forests and plantations of Pinus are ecologically and economically important worldwide, producing an array of goods and services, including the provision of non-wood forest products. Pinus species play an important role in Mediterranean and boreal forests. Although Pinus species seem to show an ecological adaptation to recurrent wildfires, a new era of mega fires is predicted, owing to climate changes associated with global warming. As a consequence, fungal communities, which are key players in forest ecosystems, could be strongly affected by these wildfires. The aim of this study was to observe the fungal community dynamics, and particularly the edible fungi, in maritime (Pinus pinaster Ait.), austrian pine (Pinus nigra J.F. Arnold), and scots pine (Pinus sylvestris L.) forests growing under wet Mediterranean, dry Mediterranean, and boreal climatic conditions, respectively, by comparing the mushrooms produced in severely burned Pinus forests in each area. Sporocarps were collected during the main sampling campaigns in non-burned plots, and in burned plots one year and five years after fire. A total of 182 taxa, belonging to 81 genera, were collected from the sampled plots, indicating a high level of fungal diversity in these pine forests, independent of the climatic conditions. The composition of the fungal communities was strongly affected by wildfire. Mycorrhizal taxa were impacted more severely by wildfire than the saprotrophic taxa, particularly in boreal forests—no mycorrhizal taxa were observed in the year following fire in boreal forests. Based on our observations, it seems that fungal communities of boreal P. sylvestris forests are not as adapted to high-intensity fires as the Mediterranean fungal communities of P. nigra and P. pinaster forests. This will have an impact on reducing fungal diversity and potential incomes in rural economically depressed areas that depend on income from foraged edible fungi, one of the most important non-wood forest products.

Download Full-text

ESTOQUES DE BIOMASSA E NUTRIENTES EM TRÊS ESPÉCIES DE Parkia EM PLANTIOS JOVENS SOBRE ÁREA DEGRADADA NA AMAZÔNIA CENTRAL

FLORESTA ◽

10.5380/rf.v44i4.34135 ◽

2014 ◽

Vol 44 (4) ◽

pp. 637

Author(s):

Karen C.P. da Costa ◽

João B.S. Ferraz ◽

Rodrigo P. Bastos ◽

Tatiane Da S. Reis ◽

Marciel J. Ferreira ◽

...

Keyword(s):

Native Forest ◽

Total Biomass ◽

Nutrient Accumulation ◽

Forest Species ◽

Coarse Roots ◽

Stem Wood ◽

Degraded Area ◽

Below Ground ◽

O 10 ◽

Harvest Method

As estratégias de distribuição de biomassa e nutrientes utilizadas pelas espécies florestais podem refletir sua capacidade de sobrevivência em plantios sobre áreas degradadas. O objetivo deste estudo foi quantificar os estoques de biomassa e nutrientes nos compartimentos arbóreos de Parkia multijuga, Parkia nitida e Parkia pendula em plantios sobre área degradada em Manaus, AM. A biomassa foi determinada pelo método destrutivo em seis árvores de cada espécie, que foram compartimentadas em: folhas, galhos finos (Ø <10 cm), galhos grossos (Ø ≥10 cm), fuste, raízes médias (2 mm ≤ Ø <5 cm) e raízes grossas (Ø ≥5 cm). Aos quatro anos, Parkia multijuga exibiu 60% do total de biomassa nos compartimentos aéreos e 40% nos subterrâneos. Parkia nitida exibiu 84% nos compartimentos aéreos e apenas 16% nos subterrâneos. Parkia pendula exibiu 67% nos compartimentos aéreos e 33% nos subterrâneos. A ordem de acúmulo de macronutrientes nos compartimentos foi: N > Ca > K > Mg > P. O fato de Parkia multijuga adotar estratégias de alocação de biomassa e nutrientes que favorecerão seu desempenho sobre sítios com baixa disponibilidade de recursos sustenta sua indicação para a composição de programas de reflorestamento em áreas degradadas na Amazônia.Palavras-chave: Espécies florestais nativas; nutrição florestal; reflorestamento; restauração. AbstractBiomass and nutrients in three species of Parkia plantings on degraded area in Central Amazon. Biomass and nutrients partitioning strategies in tree species may reflect their ability to survive in plantations on degraded areas. The objective of this study was to investigate the content of biomass and nutrients in tree components of Parkia multijuga, Parkia nitida and Parkia pendula on plantings in degraded area in Manaus, AM. The biomass was determined by the harvest method in six trees of each species, which were subdivided into leaves, fine branches (Ø < 10 cm), coarse branches (Ø ≥10 cm), stem wood, medium roots (≤ 2 mm Ø < 5 cm ) and coarse roots (Ø ≥ 5 cm). At 4 years, Parkia multijuga allocated 60% of the total biomass to above-ground components and 40% to below-ground. Parkia nitida allocated 84% to above-ground and 16% to below-ground. Parkia pendula allocated 67% to above-ground components and 33% to below-ground. The order of the nutrient accumulation in tree compartments was: N > Ca > K > Mg > P. Parkia multijuga, by adopting better strategies of distribution of biomass and nutrients, it is a recommended species for reforestation programs on degraded sites in the Amazon.Keywords: Native forest species; forest nutrition; reforestation; restoration.

Download Full-text

Simulating soil organic C dynamics in managed grasslands under humid temperate climatic conditions

10.5194/soil-2020-76 ◽

2020 ◽

Author(s):

Asma Jebari ◽

Jorge Álvaro-Fuentes ◽

Guillermo Pardo ◽

María Almagro ◽

Agustin del Prado

Keyword(s):

Field Experiments ◽

Model Performance ◽

Climatic Conditions ◽

Plant Residue ◽

Plant Residues ◽

Organic C ◽

Natural Grasslands ◽

Rothc Model ◽

Below Ground ◽

Intensively Managed

Abstract. Temperate grasslands are of paramount importance in terms of soil organic carbon (SOC) dynamics. Globally, research on SOC dynamics has largely focused on forests, croplands and natural grasslands, while intensively managed grasslands has received much less attention. In this regard, we aimed to improve the prediction of SOC dynamics in managed grasslands under humid temperate regions. In order to do so, we modified and recalibrated the SOC model RothC, originally developed to model the turnover of SOC in arable topsoils, which requires limited amount of readily available input data. The modifications proposed for the RothC are: (1) water content up to saturation conditions in the soil water function of RothC to fit the humid temperate climatic conditions, (2) entry pools that account for particularity of exogenous organic matter (EOM) applied (e.g., ruminant excreta), (3) annual variation in the carbon inputs derived from plant residues considering both above- and below-ground plant residue and rhizodeposits components as well as their quality, and (4) the livestock treading effect (i.e., poaching damage) as a common problem in humid areas with higher annual precipitation. In the paper, we describe the basis of these modifications, carry out a simple sensitivity analysis and validate predictions against data from existing field experiments from four sites in Europe. Model performance showed that modified RothC reasonably captures well the different modifications. However, the model seems to be more sensitive to soil moisture and plant residues modifications than to the other modifications. The applied changes in RothC model could be appropriate to simulate both farm and regional SOC dynamics from managed grassland-based systems under humid temperate conditions.

Download Full-text