Predicting biomass partitioning to root versus shoot in corn and velvetleaf (Abutilon theophrasti)

Knowledge of how plants will partition their new biomass will aid in understanding competition between crops and weeds. This study determined if the amount of biomass partitioned to the root versus the shoot can be predicted from tissue carbon [C] and nitrogen [N] concentrations and the daily gain in C (GC) and N (GN) for each unit shoot and root biomass, respectively. Pots measuring 28 cm diameter and 60 cm deep were embedded in the ground, and each contained one plant of either corn or velvetleaf. Each plant received one of three nitrogen treatments: 0, 1, or 3 g of nitrogen applied as ammonium nitrate in 2001 and 0, 2, or 6 g of nitrogen in 2002. Measurements of total above- and belowground biomass and tissue [C] and [N] were made at 10 different sample dates during the growing season. Fraction of biomass partitioned to roots (Pr) was predicted from [C], [N], GC, and GN. Accurate prediction of the fraction of biomass partitioned to roots versus shoots was evaluated by comparing observed and predicted Pr across all treatments. The coordination model has potential as a reliable tool for predicting plant biomass partitioning. Normalized error values were close to zero for corn in 2001 and 2002 and for velvetleaf in 2001, indicating that biomass partitioning was correctly predicted.

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Grazing depresses soil carbon storage through changing plant biomass and composition in a Tibetan alpine meadow

Plant Soil and Environment ◽

10.17221/7/2011-pse ◽

2011 ◽

Vol 57 (No. 6) ◽

pp. 271-278 ◽

Cited By ~ 36

Author(s):

D.S. Sun ◽

K. Wesche ◽

D.D. Chen ◽

S.H. Zhang ◽

G.L. Wu ◽

...

Keyword(s):

Organic Carbon ◽

Soil Carbon ◽

Carbon Storage ◽

Root Biomass ◽

Alpine Meadow ◽

Plant Biomass ◽

Grazing Intensity ◽

Growing Season ◽

Soil Carbon Storage ◽

Plant Growing Season

Grazing-induced variations in vegetation may either accelerate or reduce soil carbon storage through changes in litter quantity and quality. Here, a three-year field study (2005–2007) was conducted in Tibetan alpine meadow to address the responses of surface soil (0–15 cm) organic carbon (SOC) storage in the plant growing season (from May to September) to varying grazing intensity (represented by the residual aboveground biomass, with G0, G1, G2, and G3 standing for 100%, 66%, 55%, and 30% biomass residual, respectively), and to explore whether grazing-induced vegetation changes depress or facilitate SOC storage. Our results showed that: (i) Higher grazing intensity resulted in lower biomass of grasses and sedges, lower root biomass, and in a change in plant community composition from palatable grasses and sedges to less palatable forbs. (ii) Increased grazing reduced the SOC content and storage with only G3 showing an SOC loss during the plant growing season. (iii) Soil organic carbon storage exhibited a highly positive correlation with the residual aboveground biomass and root biomass. Our results imply that a grazing-induced reduction in plant biomass productivity and changes in species composition would depress soil carbon storage, and that an increase in grazing pressure can lead to a gradual change of alpine meadow soils from being 'carbon sinks' to become 'carbon sources'.

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Responses of Nematodes to Ungulate Herbivory on Bluebunch Wheatgrass and Idaho Fescue in Yellowstone National Park

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.1994.3211 ◽

1994 ◽

Vol 18 ◽

pp. 126-130

Author(s):

Evelyn Merrill ◽

Jon Hak ◽

Nancy Stanton

Keyword(s):

Root Growth ◽

Yellowstone National Park ◽

Root Biomass ◽

National Park ◽

Growing Season ◽

Belowground Biomass ◽

Winter Range ◽

Bluebunch Wheatgrass ◽

Festuca Idahoensis ◽

Agropyron Spicatum

Above- and belowground biomass of Idaho fescue Festuca idahoensis and bluebunch wheatgrass Agropyron spicatum and nematode densities under these plant species were sampled during the growing season inside and outside a 2-year old exclosure on Crystal Bench in Yellowstone National Park. Early in the growing season, grazed plants of both species had lower shoot and root biomass than ungrazed plants. Standing biomass of grazed plants was equal to ungrazed plants at the end of the growing season. Densities/g root biomass of phytophagous and bacterial feeding nematodes were higher under grazed than ungrazed plants of both plant species only early in the growing season. Foliar concentrations of nitrogen in grazed plants were higher than ungrazed plants but there was no difference in root nitrogen between grazed and ungrazed plants. The effects of ungulate grazing on the Northern winter range of Yellowstone National Park has recently received considerable attention (Frank 1990, Coughenour 1991, Singer 1992, Wallace submitted). Early interest in this topic centered around the question to cull or not to cull elk in the Park. However, as the concepts of "maintaining ecological processes" (Houston 1982) and "ecosystem management" (Keiter 1991) have gained acceptance in Park management, understanding the dynamics and interactions of a broader array of herbivores inhabiting the Park have become increasingly important. In this paper, we describe the results of a study which focused on the effects of aboveground herbivory on nematode density and trophic structure. Root-feeding nematodes are major herbivores in other grassland systems and may consume twice as much biomass as aboveground consumers (Ingham and Detling 1984, Stanton 1988). Houston (1982) reported that nothing is known about the effects of nematodes on the native grasses of the northern range especially in combination with aboveground grazers. We hypothesized that if spring grazing is intense, grazed plants would initially show a decline in root growth and phytophagous nematodes. Cessation of root growth is a common response of plants to grazing and may occur within the first 2-24 hours (Hodgkinson and Baas Becking 1977). Evidence to date supports the idea that phytophagous nematode densities are highest under moderate levels of grazing and low under heavily grazed and ungrazed plants (Stanton 1983, Stanton et al. 1984, Seastedt 1985, Seastedt et al. 1988). Because senescing roots, subsequent to grazing, provide increased substrates for decomposers, we also hypothesized that microbial activity and nitrogen mineralization should increase (Stanton et al. 1984). As a result, we expected to detect an increase in microbial feeding nematodes. As root regrowth occurred, we expected phytophagous nematodes to increase. However, we predicted that populations would not reach levels found under ungrazed plants because plants in grazed areas experience higher levels of nitrogen mineralization (Holland and Detling 1990) than ungrazed plants and may produce proportionally fewer numbers of root hairs (nutrient absorption organs) which serve as feeding sites for nematodes. Because of reduced densities of phytophagous nematodes and increased mineralization rates under grazed plants, we expected grazed plants to recoup their losses rapidly. The net result we predicted would be no detectable differences in aboveground or belowground biomass during years of normal rainfall. Thus, our study addressed 3 null hypotheses. First, root and shoot biomass of grazed and ungrazed plants will be similar at the end of the growing season. Second, density of phytophagous and microbial feeding nematodes will not differ between grazed and ungrazed plants. Finally, nitrogen concentration of roots and aboveground foliage will not be higher in grazed than in ungrazed plants. We focused our attention on bluebunch wheatgrass Agropyron spicatum and Idaho fescue Festuca idahoensis because of their importance as winter range forages and because Mueggler (1975) reported that bluebunch wheatgrass was more sensitive and recovered more slowly to heavy clipping than Idaho fescue.

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Can an invasive African grass affect carbon and nitrogen stocks in open habitats of the Brazilian Cerrado?

10.21203/rs.3.rs-540690/v1 ◽

2021 ◽

Author(s):

Diana Bertuol Garcia ◽

Rafael Oliveira Xavier ◽

Plinio Barbosa Camargo ◽

Simone A. Vieira ◽

Vania Regina Pivello

Keyword(s):

Aboveground Biomass ◽

Root Biomass ◽

Nutrient Dynamics ◽

Soil Surface ◽

Belowground Biomass ◽

Level Of Invasion ◽

Provision Of Services ◽

African Grasses ◽

African Grass ◽

C And N

Abstract Considering the emergence of ecosystems dominated by invasive species, there is growing interest in estimating the effect of biological invasions in ecosystem processes and provision of services. African grasses are the most invasive plants in the Cerrado (Brazilian savanna), but their impact on C and N stocks is poorly known. We compared patterns of C and N stocks in the aboveground biomass, root biomass and soil in open Cerrado (campo sujo) sites, both uninvaded and invaded by the African grass Urochloa decumbens. In both sites we estimated the aboveground biomass of U. decumbens and native grasses, as well as the root biomass up to 50 cm. We obtained C and N contents in the soil, as well as C and N stocks, up to 1 m depth, and variation in soil δ13C and δ15N. Although invasion did not affect the aboveground biomass, it did affect belowground biomass, leading to higher C stock in fine roots and soil N content close to soil surface, as well as higher C content along the soil profile. C and N soil stocks, soil δ13C and δ15N values did not significantly differ between invaded and uninvaded site. Even a relatively low level of invasion by U. decumbens changed the root distribution pattern and increased C and N contents in the upper soil, which may promote ecosystem changes by altering nutrient dynamics. Although still preliminary, our study shows that dominance by U. decumbens can have severe effects in the Cerrado belowground environment.

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Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽

10.3390/f11090943 ◽

2020 ◽

Vol 11 (9) ◽

pp. 943

Author(s):

Katri Nissinen ◽

Virpi Virjamo ◽

Antti Kilpeläinen ◽

Veli-Pekka Ikonen ◽

Laura Pikkarainen ◽

...

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Root Biomass ◽

Growing Season ◽

Silver Birch ◽

Shoot Biomass ◽

Growth Responses ◽

Growing Seasons ◽

Simulated Climate ◽

Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

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No evidence for interspecific interactions between plants in the first stage of succession on coastal dunes in subarctic Quebec, Canada

Canadian Journal of Botany ◽

10.1139/b97-100 ◽

1997 ◽

Vol 75 (6) ◽

pp. 902-915 ◽

Cited By ~ 19

Author(s):

Gilles Houle

Keyword(s):

Plant Biomass ◽

Interspecific Interactions ◽

Regional Climate ◽

Salt Spray ◽

Coastal Dunes ◽

Growing Season ◽

Coastal Dune ◽

Dune System ◽

Abiotic Conditions ◽

Herbaceous Perennials

Coastal dunes are very dynamic systems, particularly where the coast is rising as a result of isostatic rebound. In those environments, succession proceeds from plants highly tolerant to sand accumulation, salt spray, and low nutrient availability to less disturbance-tolerant and stress-tolerant, more nutrient-demanding, and supposedly more competitive species. In the subarctic, the regional climate exacerbates the stresses imposed by local abiotic conditions on the dunes. I hypothesized that facilitation would be particularly significant on the foredune of subarctic coastal dune systems because of intense stresses (local and regional) and frequent disturbance in the form of sand deposition. Belowground and aboveground plant biomass was sampled at three different periods during the 1990 growing season along transects perpendicular to the shoreline on a coastal dune system in subarctic Quebec (Canada). The three herbaceous perennials found on the foredune (Honckenya peploides, Elymus mollis, and Lathyrus japonicus) were segregated in time during the growing season and in space along the topographical gradient. The biomass of Honckenya, the first species encountered as one progresses from the upper part of the beach towards the foredune ridge, was not correlated to substrate physicochemistry. However, the biomass of Elymus and that of Lathyrus, the next two species to appear along the flank of the foredune, were related to pH, Mg, Na, and Cl (negatively), and to P and Ca (positively). These results suggest variable linkages between substrate physicochemistry and plant species along the foredune, possibly in relation to species-specific tolerance for abiotic conditions and requirements for substrate resources or to microscale influence of the plants themselves on substrate physicochemistry. Removal experiments carried out over 2 years revealed only one significant unidirectional interaction between these three species along the topographical gradient, and little plant control over abiotic variables (e.g., soil temperature, wind velocity, and photosynthetically active radiation). Early primary succession on subarctic coastal dunes (and elsewhere) appears to be under the control of strong limiting abiotic conditions. As plants slowly gain more control over the physical environment, interspecific interactions (positive and negative) may become more significant. Key words: Elymus mollis, facilitation, Honckenya peploides, inhibition, Lathyrus japonicus, removal experiment, succession, tolerance.

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Interannual Variation in Root Production in Grasslands Affected by Artificially Modified Amount of Rainfall

The Scientific World JOURNAL ◽

10.1100/2012/805298 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 7

Author(s):

Karel Fiala ◽

Ivan Tůma ◽

Petr Holub

Keyword(s):

Interannual Variation ◽

Plant Biomass ◽

Growing Season ◽

Lower Amount ◽

Root Production ◽

Climate Scenarios ◽

Natural Rainfall ◽

Plant Matter ◽

Grassland Ecosystems ◽

Below Ground

The effect of different amounts of rainfall on the below-ground plant biomass was studied in three grassland ecosystems. Responses of the lowland (dryFestucagrassland), highland (wetCirsiumgrassland), and mountain (Nardusgrassland) grasslands were studied during five years (2006–2010). A field experiment based on rainout shelters and gravity irrigation simulated three climate scenarios: rainfall reduced by 50% (dry), rainfall increased by 50% (wet), and the natural rainfall of the current growing season (ambient). The interannual variation in root increment and total below-ground biomass reflected the experimentally manipulated amount of precipitation and also the amount of current rainfall of individual years. The effect of year on these below-ground parameters was found significant in all studied grasslands. In comparison with dryFestucagrassland, better adapted to drought, submontane wetCirsiumgrassland was more sensitive to the different water inputs forming rather lower amount of below-ground plant matter at reduced precipitation.

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Do chronic aboveground O3 exposure and belowground pathogen stress affect growth and belowground biomass partitioning of juvenile beech trees (Fagus sylvatica L.)?

Plant and Soil ◽

10.1007/s11104-009-9968-2 ◽

2009 ◽

Vol 323 (1-2) ◽

pp. 31-44 ◽

Cited By ~ 8

Author(s):

J. Barbro Winkler ◽

Frank Fleischmann ◽

Sebastian Gayler ◽

Hagen Scherb ◽

Rainer Matyssek ◽

...

Keyword(s):

Fagus Sylvatica ◽

Belowground Biomass ◽

Biomass Partitioning ◽

Fagus Sylvatica L

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Effects of short-term N addition on plant biomass allocation and C and N pools of theSibiraea angustatascrub ecosystem

European Journal of Soil Science ◽

10.1111/ejss.12414 ◽

2017 ◽

Vol 68 (2) ◽

pp. 212-220 ◽

Cited By ~ 9

Author(s):

D. Wang ◽

H. L. He ◽

Q. Gao ◽

C. Z. Zhao ◽

W. Q. Zhao ◽

...

Keyword(s):

Biomass Allocation ◽

Plant Biomass ◽

N Addition ◽

Short Term ◽

C And N ◽

C And N Pools

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Herbage biomass and its relationship to soil carbon under long-term grazing in northern temperate grasslands

Canadian Journal of Plant Science ◽

10.1139/cjps-2018-0251 ◽

2019 ◽

Vol 99 (6) ◽

pp. 905-916

Author(s):

E.W. Bork ◽

M.P. Lyseng ◽

D.B. Hewins ◽

C.N. Carlyle ◽

S.X. Chang ◽

...

Keyword(s):

Soil Carbon ◽

Root Biomass ◽

Mineral Soil ◽

Belowground Biomass ◽

Cattle Grazing ◽

Shoot Biomass ◽

Positive Contribution ◽

Temperate Grasslands ◽

Soil C

While northern temperate grasslands are important for supporting beef production, it remains unclear how grassland above- and belowground biomass responds to long-term cattle grazing. Here, we use a comprehensive dataset from 73 grasslands distributed across a broad agro-climatic gradient to quantify grassland shoot, litter, and shallow (top 30 cm) root biomass in areas with and without grazing. Additionally, we relate biomass to soil carbon (C) concentrations. Forb biomass was greater (p < 0.05) in grazed areas, particularly those receiving more rainfall. In contrast, grass and total aboveground herbage biomass did not differ with grazing (total: 2320 kg ha−1 for grazed vs. 2210 kg ha−1 for non-grazed; p > 0.05). Forb crude protein concentrations were lower (p < 0.05) in grazed communities compared with those that were non-grazed. Grasslands subjected to grazing had 56% less litter mass. Root biomass down to 30 cm remained similar between areas with (9090 kg ha−1) and without (7130 kg ha−1) grazing (p > 0.05). Surface mineral soil C concentrations were positively related to peak grassland biomass, particularly total (above + belowground) biomass, and with increasing forb biomass in grazed areas. Finally, total aboveground shoot biomass and soil C concentrations in the top 15 cm of soil were both positively related to the proportion of introduced plant diversity in grazed and non-grazed grasslands. Overall, cattle grazing at moderate stocking rates had minimal impact on peak grassland biomass, including above- and belowground, and a positive contribution exists from introduced plant species to maintaining herbage productivity and soil C.

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Belowground biomass and its annual increment in a montane beech forest in Mavrovo National Park, north-west Macedonia

Journal of Forest Science ◽

10.17221/131/2010-jfs ◽

2012 ◽

Vol 58 (No. 4) ◽

pp. 152-164

Author(s):

S. Hristovski ◽

L. Melovski ◽

M. Šušlevska ◽

L. Grupče

Keyword(s):

Fine Roots ◽

Root Biomass ◽

National Park ◽

European Beech ◽

Belowground Biomass ◽

Beech Forest ◽

Volume Index ◽

Annual Increment ◽

North West ◽

Trees And Shrubs

The aim of this paper is to present the results of the investigation on belowground biomass and its annual increment in a beech ecosystem (Calamintho grandiflorae-Fagetum) in Mavrovo National Park, Republic of Macedonia. Belowground biomass was estimated in three layers of the ecosystem (tree, shrub and herb layers) for seven years during the period 1997–2005. Allometric regressions were established for the relationship of root biomass from volume index (D2H, diameter squared × height) on a sample of 10 model trees and 13 model shrubs of European beech (Fagus sylvatica L.). Fine root biomass of trees and shrubs was estimated in soil samples to a depth of 145 cm and divided into live and dead fine roots and subdivided into thickness classes. Belowground biomass of the herb layer was assessed in 20 herb species. It was estimated that the total belowground biomass in the ecosystem was 57.75 ·ha–1. The contribution of shrub and herb layers was insignificant (less than 0.2%). Biomass of the live fine roots was 10.16 t·ha–1, i.e. 18% of the total belowground biomass. Annual increment of trees and shrubs was 1.03 t·ha–1·y–1 and 4.6 kg·ha–1·y–1, respectively.

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