Root Growth Responses of Melilotis indicus (L.) All. to Air Pollution

The root length, root biomass and net primary productivity of Melilotus indicus were studied at the monthly intervals from a wheat cropland, growing at the four selected sites situated at 0.5, 2, 4 and 20 km leeward from the source of pollution caused by coal burning of a thermal power plant of Kasimpur (U.P, India). Root growth varied with the level of pollution, age of the stand and the coal consumption rate as well as the release of major gases from the power plant. The data indicate that the degree of response increased with decreasing distance from the source of pollution. The root length and root biomass were affected significantly at the 0.5 and 2 km. respectively in the seedling stage, while in the middle and old stages the loss significantly increased up to 4 km in comparison to the reference site situated at 20 km away from the source of pollution. The percent loss in the root growth of M. indicus increased from seedling to middle stage and decline at the old stage. Root length, root biomass and net primary productivity suffered greater in the middle stage, may be due to high coal consumption and greater release of gaseous pollutants from the power plant. The root length and root biomass showed a significant positive relationship with the distance from the source.Key words: Air pollution, root growth, Melilotus indicus, wheat cropland, biomass. DOI: 10.3126/eco.v16i0.3470ECOPRINT 16: 29-34, 2009

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Effects of warming and fertilization interacting with intraspecific competition on fine root traits of Picea asperata

Journal of Plant Ecology ◽

10.1093/jpe/rtaa074 ◽

2020 ◽

Author(s):

Dan-Dan Li ◽

Hong-Wei Nan ◽

Chun-Zhang Zhao ◽

Chun-Ying Yin ◽

Qing Liu

Keyword(s):

Root Growth ◽

Climate Warming ◽

Tree Growth ◽

Root Length ◽

Root Biomass ◽

Fine Root ◽

Root Traits ◽

Root Surface ◽

Root Branching ◽

Picea Asperata

Abstract Aims Competition, temperature, and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau. Although many studies have reported their individual effects on tree growth, little is known about how the interactions of competition with fertilization and temperature affect root growth. We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors. Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature (ET) and fertilization. We measured root traits, including the root tip number over the root surface (RTRS), the root branching events over the root surface (RBRS), the specific root length (SRL), the specific root area (SRA), the total fine root length and area (RL and RA), the root tips (RT) and root branching events (RB). These root traits are considered to be indicators of plant resource uptake capacity and root growth. The root biomass and the nutrient concentrations in the roots were also determined. Important Findings The results indicated that ET, fertilization and competition individually enhanced the nitrogen (N) and potassium (K) concentrations in fine roots, but they did not affect fine root biomass or root traits, including RL, RT, RA and RB. However, both temperature and fertilization, as well as their interaction, interacting with competition increased RL, RA, RT, RB, and nutrient uptake. In addition, the SRL, SRA, RTRS and RBRS decreased under fertilization, the interaction between temperature and competition decreased SRL and SRA, while the other parameters were not affected by temperature or competition. These results indicate that Picea asperata maintains a conservative nutrient strategy in response to competition, climate warming, fertilization, and their interactions. Our results improve our understanding of the physiological and ecological adaptability of trees to global change.

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Effects of light intensity and co-inoculation of arbuscular mycorrhizal fungi and rhizobium on root growth and nodulation of Indigofera tinctoria

Sains Tanah - Journal of Soil Science and Agroclimatology ◽

10.20961/stjssa.v17i2.40065 ◽

2020 ◽

Vol 17 (2) ◽

pp. 94

Author(s):

Maria Theresia Sri Budiastuti ◽

Djoko Purnomo ◽

Supriyono Supriyono ◽

Bambang Pujiasmanto ◽

Desy Setyaningrum

Keyword(s):

Light Intensity ◽

Root Growth ◽

Root Length ◽

Mycorrhizal Fungi ◽

Root Biomass ◽

Block Design ◽

Fresh Weight ◽

Microbial Inoculation ◽

Four Levels ◽

Indigofera Tinctoria

Indigofera tinctoria is a legume that is cultivated as a source of natural indigo dyes. As a legume, Indigofera tinctoria is capable of symbiosis with soil microbes. This study evaluates the effects of light intensity and microbial inoculation on root growth and nodulation. The study used a complete randomized block design with a split-plot pattern. Light intensity was the main plot with four levels of light intensity 100%, 50%, 25%, and 10%. Microbial inoculation was a subplot with four levels without inoculation, mycorrhizae inoculation, rhizobium inoculation, and double inoculation with both mycorrhizae and rhizobium. The results obtained show that light intensity and microbial inoculation affected root length, root fresh weight, root biomass, and the number of nodules. 50% light intensity was optimum for root length, while 100% light intensity was optimum for root fresh weight, root biomass, and a number of nodules. Root growth and nodulation were further increased with double inoculation. The combination of light intensity and microbial inoculation affected root biomass and nodulation. The combination of 100% light intensity and double inoculation resulted in the highest root biomass and nodule numbers. Mycorrhizae and rhizobium have a synergistic relationship to nodulation and root growth. Double inoculation with mycorrhizae and rhizobium efficiently increased root biomass and the number of nodules under low or high light intensity.

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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.

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Effect of fertilization on below-ground plant mass of submontane Polygono-Cirsietum meadow

Beskydy ◽

10.11118/beskyd201306010033 ◽

2013 ◽

Vol 6 (1) ◽

pp. 33-42

Author(s):

Petr Holub ◽

Ivan Tůma ◽

Karel Fiala

Keyword(s):

Primary Productivity ◽

Root Biomass ◽

Net Primary Productivity ◽

Growing Season ◽

Dry Mass ◽

The Czech Republic ◽

Plant Parts ◽

Below Ground ◽

Turn Over ◽

Different Levels

We assessed below-ground net primary productivity (BNPP) in the wet submontane Cirsium meadow occurred in the highland region of the Czech Republic. Effect of four different fertilization levels on BNPP was estimated in 1992. At the beginning of the growing season (April 29), total dry mass of rhizomes, roots and total below-ground plant parts of unfertilized stand reached 177, 1478 and 1657 g.m-2, respectively. Their living parts formed 42 % of their total dry mass. In comparison with unfertilized stands, however, the greatest accumulation of dry mass of rhizomes (504 g.m-2), roots (1503 g.m-2) and total below-ground dry mass (2008 g.m-2) was reached after application of 90 kgN.ha-1. Similarly, the highest BNPP values for living (435 g.m-2.yr-1) and total below-ground dry mass (351 g.m-2.yr-1) were calculated for the stand affected by the same amount of fertilization. These data show how variable role grasslands can play in accumulation and turn over of root biomass due to different levels of fertilization.

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RAINFALL REGIME ON FINE ROOT GROWTH IN A SEASONALLY DRY TROPICAL FOREST

Revista Caatinga ◽

10.1590/1983-21252020v33n218rc ◽

2020 ◽

Vol 33 (2) ◽

pp. 458-469

Author(s):

EUNICE MAIA DE ANDRADE ◽

GILBERTO QUEVEDO ROSA ◽

ALDENIA MENDES MASCENA DE ALMEIDA ◽

ANTONIO GIVANILSON RODRIGUES DA SILVA ◽

MARIA GINA TORRES SENA

Keyword(s):

Root Growth ◽

Root Length ◽

Fine Roots ◽

Root Biomass ◽

Fine Root ◽

Fine Root Biomass ◽

Rainfall Regime ◽

Seasonally Dry ◽

Fine Root Length ◽

Fine Root Growth

ABSTRACT Seasonally dry tropical forests (SDTF) usually present dry seasons of eight or more months. Considering the concerns about the resilience of SDTF to climate changes, the objective of this study was to evaluate the effect of the rainfall regime on fine root growth in a SDTF. The experiment started at the end of the wet season (July 2015), when fine roots were evaluated and ingrowth cores were implemented. The temporal growth of fine roots in the 0-30 cm soil layer was monitored, considering the 0-10, 10-20, and 20-30 cm sublayers, through six samplings from November 2015 to July 2017. The characteristics evaluated were fine root biomass, fine root length, fine root specific length, and fine root mean diameter. The significances of the root growths over time and space were tested by the Kruskal-Wallis test (p<0.05). Fine roots (Ø<2 mm) were separated and dried in an oven (65 °C) until constant weight. The root length was determined using the Giaroots software. The fine root biomass in July 2015 was 7.7±5.0 Mg ha-1 and the length was 5.0±3.2 km m-2. Fine root growth in SDTF is strongly limited by dry periods, occurring decreases in biomass and length of fine roots in all layers evaluated. Fine root growth occurs predominantly in rainy seasons, with fast response of the root system to rainfall events, mainly in root length.

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Ozone and haze pollution weakens net primary productivity in China

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-6073-2017 ◽

2017 ◽

Vol 17 (9) ◽

pp. 6073-6089 ◽

Cited By ~ 51

Author(s):

Xu Yue ◽

Nadine Unger ◽

Kandice Harper ◽

Xiangao Xia ◽

Hong Liao ◽

...

Keyword(s):

Air Pollution ◽

Primary Productivity ◽

Net Primary Productivity ◽

Carbon Sink ◽

System Modeling ◽

Surface Ozone ◽

Diffuse Radiation ◽

Atmospheric Pollutants ◽

Carbon Uptake ◽

Haze Pollution

Abstract. Atmospheric pollutants have both beneficial and detrimental effects on carbon uptake by land ecosystems. Surface ozone (O3) damages leaf photosynthesis by oxidizing plant cells, while aerosols promote carbon uptake by increasing diffuse radiation and exert additional influences through concomitant perturbations to meteorology and hydrology. China is currently the world's largest emitter of both carbon dioxide and short-lived air pollutants. The land ecosystems of China are estimated to provide a carbon sink, but it remains unclear whether air pollution acts to inhibit or promote carbon uptake. Here, we employ Earth system modeling and multiple measurement datasets to assess the separate and combined effects of anthropogenic O3 and aerosol pollution on net primary productivity (NPP) in China. In the present day, O3 reduces annual NPP by 0.6 Pg C (14 %) with a range from 0.4 Pg C (low O3 sensitivity) to 0.8 Pg C (high O3 sensitivity). In contrast, aerosol direct effects increase NPP by 0.2 Pg C (5 %) through the combination of diffuse radiation fertilization, reduced canopy temperatures, and reduced evaporation leading to higher soil moisture. Consequently, the net effects of O3 and aerosols decrease NPP by 0.4 Pg C (9 %) with a range from 0.2 Pg C (low O3 sensitivity) to 0.6 Pg C (high O3 sensitivity). However, precipitation inhibition from combined aerosol direct and indirect effects reduces annual NPP by 0.2 Pg C (4 %), leading to a net air pollution suppression of 0.8 Pg C (16 %) with a range from 0.6 Pg C (low O3 sensitivity) to 1.0 Pg C (high O3 sensitivity). Our results reveal strong dampening effects of air pollution on the land carbon uptake in China today. Following the current legislation emission scenario, this suppression will be further increased by the year 2030, mainly due to a continuing increase in surface O3. However, the maximum technically feasible reduction scenario could drastically relieve the current level of NPP damage by 70 % in 2030, offering protection of this critical ecosystem service and the mitigation of long-term global warming.

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Ozone and haze pollution weakens net primary productivity in China

10.5194/acp-2016-1025 ◽

2016 ◽

Author(s):

Xu Yue ◽

Nadine Unger ◽

Kandice Harper ◽

Xiangao Xia ◽

Hong Liao ◽

...

Keyword(s):

Air Pollution ◽

Primary Productivity ◽

Net Primary Productivity ◽

Carbon Sink ◽

System Modeling ◽

Surface Ozone ◽

Diffuse Radiation ◽

Atmospheric Pollutants ◽

Carbon Uptake ◽

Haze Pollution

Abstract. Atmospheric pollutants have both beneficial and detrimental effects on carbon uptake by land ecosystems. Surface ozone damages leaf photosynthesis by oxidizing plant cells, while aerosols promote carbon uptake by increasing diffuse radiation and exert additional influences through concomitant perturbations to meteorology and hydrology. China is currently the world's largest emitter of both carbon dioxide and short-lived air pollutants. The land ecosystems of China are estimated to provide a carbon sink, but it remains unclear whether air pollution acts to inhibit or promote carbon uptake. Here, we employ Earth system modeling and multiple measurement datasets to assess the separate and combined effects of anthropogenic ozone and aerosol pollution on net primary productivity (NPP) in China. In the present day, air pollution reduces annual NPP by 0.4 Pg C (9 %), resulting from a decrease of 0.6 Pg C (14 %) by ozone damage, and an increase of 0.2 Pg C (5 %) by aerosol direct effects. The enhancement by aerosols is a combination of diffuse radiation fertilization, reduced canopy temperatures, and reduced evaporation leading to higher soil moisture. However, precipitation inhibition from combined aerosol direct and indirect effects reduces annual NPP by 0.2 Pg C (4 %), leading to a net air pollution suppression of 0.8 Pg C (16 %). Our results reveal strong dampening effects of air pollution on the land carbon uptake in China today. Following the current legislation emission scenario, this suppression will not alleviate by the year 2030, mainly due to a continuing increase in surface ozone. However, the maximum technically feasible reduction scenario could drastically relieve the current level of NPP damage by 70 % in 2030, offering protection of this critical ecosystem service and the mitigation of long-term global warming.

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Effect of fertilization on root growth in the wet submontane meadow

Plant Soil and Environment ◽

10.17221/162/2013-pse ◽

2013 ◽

Vol 59 (No. 8) ◽

pp. 342-347 ◽

Cited By ~ 4

Author(s):

P. Holub ◽

I. Tůma ◽

K. Fiala

Keyword(s):

Czech Republic ◽

Root Growth ◽

Primary Productivity ◽

Net Primary Productivity ◽

The Czech Republic ◽

Highland Region ◽

Plant Matter ◽

Different Levels

Root net primary productivity (RNPP) was assessed in the wet submontane meadow in the highland region of the Czech Republic. RNPP was studied from 1992 to 1995 with help of the in-growth core technique. The effect of different intensities of fertilization on root growth was covered. In comparison with unfertilized stands, the application of fertilizers (90 kg N/ha) resulted, mostly significantly, in greater root productivity (297 g/m2/year and 2.08 g/m2/day, on average). This represented an increase by 72% and 71%, respectively. Variability in the fraction of RNPP to total net primary productivity was examined. Results indicate that this fraction varied from 0.18 to 0.25 across the compared treatments and decreased with increasing fertilization. Data show how different roles can grasslands play in accumulation of plant matter due to different levels of fertilization.

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