Microplastics have shape- and polymer-dependent effects on soil processes

AbstractMicroplastics are a diverse and ubiquitous contaminant, a global change driver with potential to alter ecosystem properties and processes. Microplastic-induced effects in soils are manifold as microplastics differ in a variety of properties among which the shape is of special interest. Microplastic shapes can resemble natural forms or be dissimilar from natural objects. Our knowledge is limited regarding the impact of various microplastic shapes on soil processes. Therefore, we conducted this two-part research comprising a meta-analysis on published literature and a lab experiment focusing on microplastic shapes- and polymer-induced effects on soil aggregation and organic matter decomposition. We here focus on fibers, films, foams and fragments as microplastic shapes.In the meta-analysis, we revealed a strong research focus on fibrous and particulate microplastic materials, with films and foams neglected.Our experiment showed that microplastic shapes are important modulators of responses in soil aggregation and organic matter decomposition. Fibers, irrespective of their chemistry, negatively affected the formation of aggregates. This supported the shape dissimilarity hypothesis. However, for other shapes like foams and fragments, the polymer identity is clearly an important factor co-modulating the soil responses.Further research is needed to generate a data-driven foundation to build on our developing mechanistic understanding of the importance and consequences of microplastic shapes added to our soils.

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Microplastics have shape- and polymer-dependent effects on soil aggregation and organic matter loss – an experimental and meta-analytical approach

Microplastics and Nanoplastics ◽

10.1186/s43591-021-00007-x ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Anika Lehmann ◽

Eva F. Leifheit ◽

Maurice Gerdawischke ◽

Matthias C. Rillig

Keyword(s):

Organic Matter ◽

Meta Analysis ◽

Organic Matter Decomposition ◽

Soil Aggregation ◽

Data Driven ◽

Soil Processes ◽

Research Focus ◽

Organic Matter Loss ◽

The Impact ◽

Soil Responses

AbstractMicroplastics are a diverse and ubiquitous contaminant, a global change driver with potential to alter ecosystem properties and processes. Microplastic-induced effects in soils are manifold as microplastics differ in a variety of properties among which the shape is of special interest. Our knowledge is limited regarding the impact of various microplastic shapes on soil processes. Therefore, we conducted this two-part research comprising a meta-analysis on published literature and a lab experiment focusing on microplastic shapes- and polymer-induced effects on soil aggregation and organic matter decomposition. We here focus on fibers, films, foams and particles as microplastic shapes.In the meta-analysis, we found a strong research focus on fibrous and particulate microplastic materials, with films and foams neglected.Our experiment showed that microplastic shapes are important modulators of responses in soil aggregation and organic matter decomposition. Fibers, irrespective of their chemistry, negatively affected the formation of aggregates. However, for other shapes like foams and particles, the polymer identity is an important factor co-modulating the soil responses.Further research is needed to generate a data-driven foundation to permit a better mechanistic understanding of the importance and consequences of microplastics added to soils.

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Soil aggregation and organic carbon of Oxisols under coffee in agroforestry systems

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832014000100028 ◽

2014 ◽

Vol 38 (1) ◽

pp. 278-287 ◽

Cited By ~ 8

Author(s):

Gabriel Pinto Guimarães ◽

Eduardo de Sá Mendonça ◽

Renato Ribeiro Passos ◽

Felipe Vaz Andrade

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Aggregation ◽

Root Penetration ◽

Conventional System ◽

Physical Quality ◽

Soil Physical Quality ◽

Organic Coffee ◽

On Farm ◽

The Impact

Intensive land use can lead to a loss of soil physical quality with negative impacts on soil aggregates, resistance to root penetration, porosity, and bulk density. Organic and agroforestry management systems can represent sustainable, well-balanced alternatives in the agroecosystem for promoting a greater input of organic matter than the conventional system. Based on the hypothesis that an increased input of organic matter improves soil physical quality, this study aimed to evaluate the impact of coffee production systems on soil physical properties in two Red-Yellow Oxisols (Latossolos Vermelho-Amarelos) in the region of Caparaó, Espirito Santo, Brazil. On Farm 1, we evaluated the following systems: primary forest (Pf1), organic coffee (Org1) and conventional coffee (Con1). On Farm 2, we evaluated: secondary forest (Sf2), organic coffee intercropped with inga (Org/In2), organic coffee intercropped with leucaena and inga (Org/In/Le2), organic coffee intercropped with cedar (Org/Ced2) and unshaded conventional coffee (Con2). Soil samples were collected under the tree canopy from the 0-10, 10-20 and 20-40 cm soil layers. Under organic and agroforestry coffee management, soil aggregation was higher than under conventional coffee. In the agroforestry system, the degree of soil flocculation was 24 % higher, soil moisture was 80 % higher, and soil resistance to penetration was lower than in soil under conventional coffee management. The macroaggregates in the organic systems, Org/In2, Org/In/Le2, and Org/Ced2 contained, on average, 29.1, 40.1 and 34.7 g kg-1 organic carbon, respectively. These levels are higher than those found in the unshaded conventional system (Con2), with 20.2 g kg-1.

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Organic Matter Decomposition, Mold Flora, and Soil Aggregation Relationships

Soil Science Society of America Journal ◽

10.2136/sssaj1943.036159950007000c0032x ◽

1943 ◽

Vol 7 (C) ◽

pp. 215-217 ◽

Cited By ~ 13

Author(s):

T. L. Martin ◽

D. A. Anderson

Keyword(s):

Organic Matter ◽

Organic Matter Decomposition ◽

Soil Aggregation

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A systematic review and meta-analysis of vineyard techniques used to delay ripening.

10.31220/agrirxiv.2021.00112 ◽

2021 ◽

Author(s):

Pietro Previtali ◽

Filippo Giorgini ◽

Randall S. Mullen ◽

Nick K. Dookozlian ◽

Kerry L. Wilkinson ◽

...

Keyword(s):

Systematic Review ◽

Quantitative Data ◽

Meta Analysis ◽

Data Driven ◽

Experimental Conditions ◽

Factors Affecting ◽

Apical Bud ◽

Grape Quality ◽

Source Limitation ◽

The Impact

Abstract Several vineyard techniques have been proposed to delay grape maturity in light of the advanced maturation driven by increasingly frequent water and heat stress events that are detrimental to grape quality. These studies differ in terms of their experimental conditions, and in the present work we have attempted to summarize previous observations in a quantitative, data-driven systematic review. A meta-analysis of quantitative data gathered across 43 relevant studies revealed the overall significance of the proposed treatments and evaluated the impact of different experimental conditions on the outcome of antitranspirants, delayed pruning and late source limitation. Antitranspirants were most effective when applied twice and closer to veraison, while di-1-p-menthene increased the ripening delay by about 1°Brix compared to kaolin. Larger ripening delays were achieved with delayed pruning of low-yielding vines or by pruning at later stages of apical bud development. Late defoliation or shoot trimming delayed ripening in high-yielding vines and represent suitable solutions for late-harvested varieties, but became ineffective where the treatment decreased yield. This quantitative meta-analysis of 242 primary observations uncovers factors affecting the efficacy of vineyard practices to delay ripening, which should be carefully considered by grape growers attempting to achieve this outcome.

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Seasonal Variations Affect The Ecosystem Functioning And Microbial Assembly Processes In Plantation Forests

10.21203/rs.3.rs-1075931/v1 ◽

2021 ◽

Author(s):

Min Wang ◽

Abolfazl Masoudi ◽

Can Wang ◽

Liqiang Zhao ◽

Jia Yang ◽

...

Keyword(s):

Organic Matter ◽

Dispersal Limitation ◽

Organic Matter Decomposition ◽

Functional Categories ◽

Soil Microbial ◽

Plantation Forests ◽

Nutrient Stocks ◽

Functional Patterns ◽

High Level ◽

The Impact

Abstract Background: While afforestation mitigates climate concerns, the impact of afforestation on soil microbial compositions, ecological assembly processes, and multiple soil functions (multifunctionality) in afforested areas remains unclear. The Xiong'an New Area plantation forests (Pinus and Sophora forests) were selected to examine the effects of plantation types in four contrasting seasons on soil microbiomes.Results: We evaluated three functional categories (nutrient stocks, organic matter decomposition, and microbial functional genes) of multifunctionality, and the average (net) multifunctionality was quantified. The results showed that net soil multifunctionality as a broad function did not change seasonally, unlike other narrow functional categories. Bacterial communities were deterministically (variable selection and homogenous selection) structured, whereas the stochastic process of dispersal limitation was mainly responsible for the assembly and turnover of fungal and protist communities. Additionally, we showed that winter triggered an abrupt transition in the bacterial community assembly from deterministic to stochastic processes in Pinus forests that was closely associated with a reduction in the bacterial Shannon diversity, with functional patterns of a high level of nutrient cycling (nutrient stocks and organic matter decomposition). Conclusions: Overall, the present study contributes local-ecosystem prospects to model the behavior of soil biota seasonally and their implied effects on soil functioning and microbial assembly processes in plantation forests.

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The Impact of Redox Fluctuations on Soil Organic Matter Decomposition in Tropical Forest Soils

10.46427/gold2020.185 ◽

2020 ◽

Author(s):

Amrita Bhattacharyya ◽

Ashley Campbell ◽

Rachel Hestrin ◽

Yang Lin ◽

Malak Tfaily ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Tropical Forest ◽

Forest Soils ◽

Organic Matter Decomposition ◽

Soil Organic Matter Decomposition ◽

The Impact

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The Impact of Dredging Deep Pits on Organic Matter Decomposition in Sediments

Water Air & Soil Pollution ◽

10.1023/b:wate.0000044853.63461.53 ◽

2004 ◽

Vol 158 (1) ◽

pp. 237-259 ◽

Cited By ~ 45

Author(s):

Boena Graca ◽

Dorota Burska ◽

Katarzyna Matuszewska

Keyword(s):

Organic Matter ◽

Organic Matter Decomposition ◽

The Impact ◽

Deep Pits

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Consequences of removal of exotic species (eucalyptus) on carbon and nitrogen cycles in the soil-plant system in a secondary tropical Atlantic forest in Brazil with a dual-isotope approach

PeerJ ◽

10.7717/peerj.9222 ◽

2020 ◽

Vol 8 ◽

pp. e9222

Author(s):

Milena Carvalho Teixeira ◽

Angela Pierre Vitória ◽

Carlos Eduardo de Rezende ◽

Marcelo Gomes de Almeida ◽

Gabriela B. Nardoto

Keyword(s):

Organic Matter ◽

Exotic Species ◽

Atlantic Forest ◽

Secondary Forest ◽

Organic Matter Decomposition ◽

Decomposition Process ◽

Dual Isotope ◽

Carbon And Nitrogen ◽

Plant System ◽

The Impact

The impact of exotic species on heterogeneous native tropical forest requires the understanding on which temporal and spatial scales these processes take place. Functional tracers such as carbon (δ13C) and nitrogen (δ15N) isotopic composition in the soil-plant system might help track the alterations induced by the exotic species. Thus, we assess the effects from the removal of the exotic species eucalyptus (Corymbia cytriodora) in an Atlantic forest Reserve, and eucalyptus removal on the alteration of the nutrient dynamics (carbon and nitrogen). The hypotheses were: (1) the eucalyptus permanence time altered δ13C and δ15N in leaves, soils and litter fractions (leaves, wood, flowers + fruits, and rest); and (2) eucalyptus removal furthered decomposition process of the soil organic matter. Hence, we determined the soil granulometry, the δ13C and δ15N in leaves, in the superficial soil layer, and litter in three sites: a secondary forest in the Atlantic forest, and other two sites where eucalyptus had been removed in different times: 12 and 3 months ago (M12 and M3, respectively). Litter samples presented intermediate δ13C and δ15N values in comparison with leaves and soil. In the M3, the greater δ13C values in both litter rest fraction and soil indicate the presence, cycling and soil incorporation of C, coming from the C4 photosynthesis of grassy species (Poaceae). In the secondary forest, the soil δ15N values were twice higher, compared with the eucalyptus removal sites, revealing the negative influence from these exotic species upon the ecosystem N dynamics. In the M12, the leaves presented higher δ13C mean value and lower δ15N values, compared with those from the other sites. The difference of δ13C values in the litter fractions regarding the soil led to a greater fractioning of 13C in all sites, except the flower + fruit fractions in the secondary forest, and the rest fraction in the M3 site. We conclude that the permanence of this exotic species and the eucalyptus removal have altered the C and N isotopic and elemental compositions in the soil-plant system. Our results suggest there was organic matter decomposition in all litter fractions and in all sites. However, a greater organic matter decomposition process was observed in the M3 soil, possibly because of a more intense recent input of vegetal material, as well as the presence of grassy, easily-decomposing herbaceous species, only in this site. Therefore, the dual-isotope approach generated a more integrated picture of the impact on the ecosystem after removing eucalyptus in this secondary Atlantic forest, and could be regarded as an option for future eucalyptus removal studies.

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