Pea-based cover crop mixtures have greater plant belowground biomass, but lower plant aboveground biomass than a pure stand of pea

Grassland ecosystems, an important component of the terrestrial environment, play an essential role in the global carbon cycle and balance. We considered four different grazing intensities on a Stipa breviflora desert steppe: heavy grazing (HG), moderate grazing (MG), light grazing (LG), and an area fenced to exclude livestock grazing as the Control (CK). The analyses of the aboveground biomass, litter, belowground biomass, soil organic carbon and soil light fraction organic carbon were utilised to study the organic carbon stock characteristics in the S. breviflora desert steppe under different grazing intensities. This is important to reveal the mechanisms of grazing impact on carbon processes in the desert steppe, and can provide a theoretical basis for conservation and utilisation of grassland resources. Results showed that the carbon stock was 11.98–44.51 g m–2 in aboveground biomass, 10.43–36.12 g m–2 in plant litters, and 502.30–804.31 g m–2 in belowground biomass (0–40 cm). It was significantly higher in CK than in MG and HG. The carbon stock at 0–40-cm soil depth was 7817.43–9694.16 g m–2, and it was significantly higher in LG than in CK and HG. The total carbon stock in the vegetation-soil system was 8342.14–10494.80 g m–2 under different grazing intensities, with the largest value in LG, followed by MG, CK, and HG. About 90.54–93.71% of the total carbon in grassland ecosystem was reserved in soil. The LG and MG intensities were beneficial to the accumulation of soil organic carbon stock. The soil light fraction organic carbon stock was 484.20–654.62 g m–2 and was the highest under LG intensity. The LG and MG intensities were beneficial for soil nutrient accumulation in the desert steppe.

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Remediation of degraded arable steppe soils in Moldova using vetch as green manure

Solid Earth ◽

10.5194/se-6-609-2015 ◽

2015 ◽

Vol 6 (2) ◽

pp. 609-620 ◽

Cited By ~ 13

Author(s):

M. Wiesmeier ◽

M. Lungu ◽

R. Hübner ◽

V. Cerbari

Keyword(s):

Cover Crop ◽

Belowground Biomass ◽

Relative Increase ◽

Hairy Vetch ◽

Arable Soils ◽

Carbon And Nitrogen ◽

Cover Cropping ◽

Arable Farming ◽

The Republic ◽

Continental Climate

Abstract. In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). The aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch (Vicia sativa) as cover crop under the dry continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch mainly due to increases of aggregate-occluded and mineral-associated OC. This was related to a high above- and belowground biomass production of hairy vetch associated with a high input of carbon and nitrogen into arable soils. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha−1yr−1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequester substantial amounts of atmospheric C in arable soils of Moldova.

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Effects of Stand Age on Biomass Allocation and Allometry of Quercus Acutissima in the Central Loess Plateau of China

Forests ◽

10.3390/f10010041 ◽

2019 ◽

Vol 10 (1) ◽

pp. 41 ◽

Cited By ~ 7

Author(s):

Bin Yang ◽

Wenyan Xue ◽

Shichuan Yu ◽

Jianyun Zhou ◽

Wenhui Zhang

Keyword(s):

Biomass Allocation ◽

Aboveground Biomass ◽

Belowground Biomass ◽

Stem Bark ◽

Stand Age ◽

Tree Biomass ◽

Quercus Acutissima ◽

Stem Wood ◽

Biomass Equations ◽

Total Tree

We studied the effects of stand age on allocation and equation fitting of aboveground and below-ground biomass in four Quercus acutissima stands (14, 31, 46, and 63 years old) in the Central Loess Plateau of China. The stem wood, stem bark, branch, foliage, and belowground biomass of each of the 20 destructive harvesting trees were quantified. The mean total biomass of each tree was 28.8, 106.8, 380.6, and 603.4 kg/tree in the 14-, 31-, 46-, and 63-year-old stands, respectively. Aboveground biomass accounted for 72.25%, 73.05%, 76.14%, and 80.37% of the total tree biomass in the 14-, 31-, 46-, and 63-year-old stands, respectively, and stem wood was the major component of tree biomass. The proportion of stem (with bark) biomass to total tree biomass increased with stand age while the proportions of branch, foliage, and belowground biomass to total tree biomass decreased with stand age. The ratio of belowground biomass to aboveground biomass decreased from 0.39 in the 14-year-old stand to 0.37, 0.31, and 0.24 in the 31-, 46-, and 63-year-old stands, respectively. Age-specific biomass equations in each stand were developed for stem wood, stem bark, aboveground, and total tree. The inclusion of tree height as a second variable improved the total tree biomass equation fitting for middle-aged (31-year-old and 46-year-old) stands but not young (14 years old) and mature (63 years old) stands. Moreover, biomass conversion and expansion factors (BCEFs) varied with stand age, showing a decreasing trend with increasing stand age. These results indicate that stand age alters the biomass allocation of Q. acutissima and results in age-specific allometric biomass equations and BCEFs. Therefore, to obtain accurate estimates of Q. acutissima forest biomass and carbon stocks, age-specific changes need to be considered.

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Summer warming effects on biomass production and clonal growth of Leymus chinensis

Crop and Pasture Science ◽

10.1071/cp10012 ◽

2010 ◽

Vol 61 (8) ◽

pp. 670 ◽

Cited By ~ 17

Author(s):

Jun-Feng Wang ◽

Song Gao ◽

Ji-Xiang Lin ◽

Yong-Guang Mu ◽

Chun-Sheng Mu

Keyword(s):

Biomass Production ◽

Aboveground Biomass ◽

Clonal Growth ◽

Belowground Biomass ◽

Growth Strategy ◽

Perennial Grasses ◽

Leymus Chinensis ◽

Shoot Number ◽

Summer Warming ◽

Rhizome Buds

Understanding how the biomass production and clone growth of perennial grasses respond to summer warming is crucial for understanding how grassland productivity responds to global warming. Here, we experimentally investigated the effects of summer warming on the biomass production and clonal growth of potted Leymus chinensis in a phytotron. Summer warming significantly decreased the biomass of both parent and daughter shoots, slightly increased the belowground biomass, and lead to a significant increase in root : shoot ratio. Warming significantly increased the total belowground bud number and decreased the daughter shoot number. Importantly, the proportions of each type of bud changed; vertical apical rhizome buds decreased, while horizontal rhizome buds increased in number. The change in proportions of each type of bud is closely related to the decrease in daughter shoot number, rhizome number and length, as well as the decrease in aboveground biomass and increase in belowground biomass. These results indicate that, as a rhizomatous, perennial grass, L. chinensis adopts a selective growth strategy that reduces the energy allocated to aboveground growth and emphasises the development of belowground organs. The implication is that continued summer warming, will further reduce the aboveground biomass production of temperate grasslands dominated by rhizomatous, perennial grasses. Inevitably, species that depend on these grasses for forage will suffer should global climate warming continue.

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Common Ragweed (Ambrosia artemisiifolia) Growth as Affected by Plant Density and Clipping

Weed Technology ◽

10.1614/wt-d-09-00070.1 ◽

2011 ◽

Vol 25 (2) ◽

pp. 268-276 ◽

Cited By ~ 23

Author(s):

Cristina Patracchini ◽

Francesco Vidotto ◽

Aldo Ferrero

Keyword(s):

Leaf Area ◽

Plant Height ◽

Aboveground Biomass ◽

Plant Density ◽

Northern Italy ◽

Ambrosia Artemisiifolia ◽

Past Century ◽

Pure Stand ◽

Area Index ◽

Common Ragweed

During the past century, common ragweed has spread from its native eastern North America to Europe, where it has become an increasing problem from both an agricultural and a human health perspective. Two field experiments were performed over a 2-yr period in a naturally infested fallow field in northern Italy to evaluate the effects of common ragweed plant density on its growth dynamics and to study its response to clipping. In the first experiment, three plant densities were tested (4, 12.5, and 25 plants m−2) and plant height, aboveground biomass, and leaf area were assessed. Intraspecific competition had a substantial negative effect on leaf area and aboveground biomass on a per plant basis in both years, but did not affect plant height. However, the high-density (25 plants m−2) treatment resulted in the highest total aboveground biomass (1,428 and 4,377 g m−2) and leaf area index (5.6 and 12.6 m2m−2) in 2006 and 2007, respectively. In the second experiment, common ragweed plants were clipped at reaching 20 cm (four clippings during the season), 50 cm (three clippings), or 80 cm (two clippings) plant height. Number of surviving plants, flowering plants, and aboveground biomass were assessed before each clipping. Clipping resulted in a partial reduction in the surviving plants and did not prevent flowering. Under the most stressing condition (clipping at 20 cm height), more than 67% of plants survived to the last clipping and, among these, more than 97% flowered, whereas before the last clipping at reaching 80 cm height from 50 to 100% of plants survived and 100% of them flowered. These findings in northern Italy confirm that common ragweed is a fast-growing annual species, capable of producing considerable aboveground biomass at various pure stand densities and that plants can still flower from plants clipped at various frequencies.

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Construction of compatible and additive individual-tree biomass models for Pinus tabulaeformis in China

Canadian Journal of Forest Research ◽

10.1139/cjfr-2016-0342 ◽

2017 ◽

Vol 47 (4) ◽

pp. 467-475 ◽

Cited By ~ 11

Author(s):

WeiSheng Zeng ◽

LianJin Zhang ◽

XinYun Chen ◽

ZhiChu Cheng ◽

KeXi Ma ◽

...

Keyword(s):

Aboveground Biomass ◽

Belowground Biomass ◽

Pinus Tabulaeformis ◽

Stem Volume ◽

Mean Annual Precipitation ◽

Mean Annual Temperature ◽

Tree Biomass ◽

Individual Tree ◽

Chinese Pine ◽

Biomass Models

Current biomass models for Chinese pine (Pinus tabulaeformis Carr.) fail to accurately estimate biomass in large geographic regions because they were usually based on limited sample trees on local sites, incompatible with stem volume, and not additive among components and total biomass. This study was based on mensuration data of individual-tree biomass from large samples of Chinese pine. The purpose was to construct compatible and additive biomass models using the nonlinear error-in-variable simultaneous equations and dummy variable modeling approach. This approach could ensure compatibility of an aboveground biomass model with a biomass conversion factor (BCF) and a stem volume model and compatibility of a belowground biomass model with a root-to-shoot ratio (RSR) model. Also, stem, branch, and foliage biomass models were additive to the aboveground biomass model. Results showed that mean prediction errors (MPEs) of the developed one- and two-variable aboveground biomass models were less than 4% and MPEs of the three-component (stem, branch, and foliage) and belowground biomass models were less than 10%. Furthermore, the effects of main climate variables on above- and below-ground biomass were analyzed. Aboveground biomass was related to mean annual temperature (MAT), while belowground biomass had no significant relationship with either MAT or mean annual precipitation (MAP). The developed models provide a good basis for estimating biomass of Chinese pine forests.

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Above and Belowground Relative Yield Total of Clover–Ryegrass Mixtures Exceed One in Wet and Dry Years

Agriculture ◽

10.3390/agriculture11030206 ◽

2021 ◽

Vol 11 (3) ◽

pp. 206

Author(s):

Inga Dirks ◽

Juliane Streit ◽

Catharina Meinen

Keyword(s):

Perennial Ryegrass ◽

White Clover ◽

Aboveground Biomass ◽

Relative Yield ◽

Belowground Biomass ◽

Soil Layers ◽

Vertical Root Distribution ◽

Shallow Soil ◽

Relative Yield Total ◽

Species Specific

Grassland mixtures hold the potential for increasing biomass and productivity. In a field experiment, monocultures and mixtures of eight white clover (Trifolium repens L.) genotypes and perennial ryegrass (Lolium perenne L.) were analyzed over three years (2015, 2016, and 2018) for their species-specific aboveground and belowground biomass. Roots were analyzed by Fourier transform infrared (FTIR) spectroscopy to identify species-specific root mass, vertical distribution, and belowground relative yield total (RYT). Aboveground biomass decreased strongly from 2015 to 2018. Aboveground and belowground RYT were always significantly higher than one. Aboveground biomass overyielded in 2016 and 2018 compared to monocultures. Monocultures of perennial ryegrass displayed a significantly higher proportion of roots in shallow soil layers than white clover in two of the three examined years. In mixtures, these differences in vertical root distribution between both species were not present and perennial ryegrass, and white clover occupied similar vertical niches in 2015 and 2016. Interestingly, in the dry year 2018, white clover had a higher proportion of roots in shallow soil layers than perennial ryegrass in mixtures.

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Tensile Characteristics of Polygonaceae Weed Roots in Slope Collapse Watershed

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1792 ◽

2013 ◽

Vol 690-693 ◽

pp. 1792-1795

Author(s):

Xiao Ming Zhang ◽

Shu Wen Ding ◽

Shuang Xi Li

Keyword(s):

Aboveground Biomass ◽

Tensile Force ◽

Belowground Biomass ◽

Scientific Basis ◽

Root Diameter ◽

Electrical Machine ◽

Fresh Weight ◽

Single Root ◽

Slope Collapse ◽

The Relationship

Root systems, as the reinforced materials, are essential to increase slope stability and mitigate soil erosion. Polygonaceae family weeds are widespread in slope collapse watershed for its rapid growth and hardiness. Some growing around farmlands and ditches affect the farm crop yield. While others growing in slope collapse have medicinal value, revegetation, and root reinforcement effect. The plant height, fresh weight and expansion range of aboveground biomass and roots were measured to research the relationship between the aboveground biomass and the belowground biomass. The relationship between the aboveground biomass fresh weight and root system fresh weight was consistent with linear function. Single root was tested by digital display push-tension meter (SH-100) fixed in vertical electrical machine (SJY-500) to obtain the relationship between tensile force and root diameter. The relationship between tensile force and root diameter conformed to exponential decay function. At last, the relationship between root diameter classes and average tensile force of Polygonaceae family weeds was analyzed. The result showed that the diameters mainly ranged from 0 mm to 2 mm, 87.75% of the total, and the average tensile force increased with the diameter class. At the beginning, the shape of tensile force was a line, then a curved line during pulling, which deformation was nonlinear. It could provide a scientific basis for design of weeder in farmland, and greening, erosion control in slope collapse.

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Biomass and total carbon in oak forests of Southern Colombian Andes: contributions to the REDD+ project-wide approach.

Revista de Biología Tropical ◽

10.15517/rbt.v64i1.18221 ◽

2016 ◽

Vol 64 (1) ◽

pp. 399

Author(s):

Adriana Yepes ◽

Andrés Sierra ◽

Luz Milena Niño ◽

Manuel López ◽

César Garay ◽

...

Keyword(s):

Tropical Forests ◽

Aboveground Biomass ◽

Belowground Biomass ◽

Carbon Stocks ◽

Total Carbon ◽

Biomass Estimation ◽

Natural Forests ◽

Colombian Andes ◽

Greenhouse Emission

Carbon estimations in tropical forests are very important to understand the role of these ecosystems in the carbon cycle, and to support decisions and the formulation of mitigation and adaptive strategies to reduce the greenhouse emission gases (GHG). Nevertheless, detailed ground-based quantifications of total carbon stocks in tropical montane forests are limited, despite their high value in science and ecosystem management (e.g. REDD+). The objective was to identify the role of these ecosystems as carbon stocks, to evaluate the contribution of the pools analyzed (aboveground biomass, belowground biomass and necromass), and to make contributions to the REDD+ approach from the project scale. For this study, we established 44 plots in a heterogeneous landscape composed by old-grown forests located in the Southern Colombian Andes. In each plot, all trees, palms and ferns with diameter (D) ≥ 15 cm were measured. In the case of palms, the height was measured for 40 % of the individuals, following the Colombia National Protocol to estimate biomass and carbon in natural forests. National allometric equations were used to estimate aboveground biomass, and a global equation proposed by IPCC was used for belowground biomass estimation; besides, palms’ aboveground biomass was estimated using a local model. The necromass was estimated for dead standing trees and the gross debris. In the latter case, the length and diameters of the extremes in the pieces were measured. Samples for wood density estimations were collected in the field and analyzed in the laboratory. The mean total carbon stock was estimated as 545.9 ± 84.1 Mg/ha (± S.E.). The aboveground biomass contributed with 72.5 %, the belowground biomass with 13.6 %, and the necromass with 13.9 %. The main conclusion is that montane tropical forests store a huge amount of carbon, similar to low land tropical forests. In addition, the study found that the inclusion of other pools could contribute with more than 20 % to total carbon storage, indicating that estimates that only include the aboveground biomass, largely underestimate carbon stocks in tropical forest ecosystems. These results support the importance of including other carbon pools in REDD+ initiatives’ estimations.

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Root and shoot growth of spring wheat (Triticum aestivum L.) are differently affected by increasing subsoil biopore density when grown under different subsoil moisture

Biology and Fertility of Soils ◽

10.1007/s00374-021-01597-7 ◽

2021 ◽

Author(s):

Mirjam Koch ◽

Roberta Boselli ◽

Mario Hasler ◽

Christian Zörb ◽

Miriam Athmann ◽

...

Keyword(s):

Nutrient Uptake ◽

Aboveground Biomass ◽

Root Biomass ◽

Column Experiment ◽

Lumbricus Terrestris ◽

Belowground Biomass ◽

Triticum Aestivum L ◽

Subsoil Water ◽

Moisture Regimes ◽

Root And Shoot Growth

AbstractA column experiment with five different pore densities (0, 1, 2, 3, and 4 pores column−1) and two varying moisture regimes (comparatively dry and comparatively moist regime) in the subsoil part of the columns was established. In each pore, Lumbricus terrestris was introduced for 28 days before sowing wheat plants. After 40 days of plant growth, watering was stopped to induce progressive topsoil drying. Parameters describing the shoot hydration, mineral uptake, and aboveground biomass were quantified. Root biomass and root length densities (RLD) were measured separately for six soil layers. Under dry subsoil conditions, plants grown under increasing biopore density showed an increase of the RLD and an improved shoot hydration but the aboveground biomass was unaffected. Since RLD but not root biomass was enhanced, it is assumed that roots were able to explore a larger volume of soil with the same amount of root biomass. Thereby, subsoil water likely was used more efficiently leading to an improved hydration. Under moist subsoil conditions, plants grown with increasing biopore density revealed enhanced shoot biomasses and nutrient uptake while the belowground biomass was unaffected. The improved nutrient uptake can be ascribed to, first, the higher subsoil water availability favoring mass flow driven nutrient uptake, and second, to direct and indirect effects of earthworms on the availability of soil nutrients. It is concluded that high biopore abundancies have the potential to improve not only the belowground but also the aboveground biomass. This, however, largely depends on subsoil moisture.

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