scholarly journals 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 ◽  
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.

scholarly journals Using Advanced Spectroscopy and Organic Matter Characterization to Evaluate the Impact of Oxidation on Cyanobacteria

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 278 ◽  
Author(s):  
Saber Moradinejad ◽  
Caitlin M. Glover ◽  
Jacinthe Mailly ◽  
Tahere Zadfathollah Seighalani ◽  
Sigrid Peldszus ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Potassium Permanganate ◽  
Drinking Water Treatment ◽  
Carbon And Nitrogen ◽  
Toxic Cyanobacteria ◽  
Nitrogen Detection ◽  
Algal Organic Matter ◽  
Organic Matter Fractions ◽  
The Impact

Drinking water treatment plants throughout the world are increasingly facing the presence of toxic cyanobacteria in their source waters. During treatment, the oxidation of cyanobacteria changes cell morphology and can potentially lyse cells, releasing intracellular metabolites. In this study, a combination of techniques was applied to better understand the effect of oxidation with chlorine, ozone, potassium permanganate, and hydrogen peroxide on two cell cultures (Microcystis, Dolichospermum) in Lake Champlain water. The discrepancy observed between flow cytometry cell viability and cell count numbers was more pronounced for hydrogen peroxide and potassium permanganate than ozone and chlorine. Liquid chromatography with organic carbon and nitrogen detection was applied to monitor the changes in dissolved organic matter fractions following oxidation. Increases in the biopolymer fraction after oxidation with chlorine and ozone were attributed to the release of intracellular algal organic matter and/or fragmentation of the cell membrane. A novel technique, Enhanced Darkfield Microscopy with Hyperspectral Imaging, was applied to chlorinated and ozonated samples. Significant changes in the peak maxima and number of peaks were observed for the cell walls post-oxidation, but this effect was muted for the cell-bound material, which remained relatively unaltered.

Contrasting above- and belowground organic matter decomposition and carbon and nitrogen dynamics in response to warming in High Arctic tundra

2018 ◽  
Vol 24 (6) ◽  
pp. 2660-2672 ◽  
Author(s):  
Daan Blok ◽  
Samuel Faucherre ◽  
Imre Banyasz ◽  
Riikka Rinnan ◽  
Anders Michelsen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Arctic Tundra ◽  
High Arctic ◽  
Nitrogen Dynamics ◽  
Organic Matter Decomposition ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Dynamics

scholarly journals Impact of Farming Activities on Vegetation in Olokemeji Forest Reserve, Nigeria

2013 ◽  
Vol 6 (2) ◽  
pp. 131-140 ◽  
Keyword(s):  
Exotic Species ◽  
Secondary Forest ◽  
Diversity Indices ◽  
Plant Resources ◽  
Degraded Lands ◽  
Forest Zone ◽  
Forest Reserve ◽  
Intensive Farming ◽  
Low Diversity ◽  
The Impact

An investigation was carried out in Olokemeji Forest Reserve (Nigeria) to examine the impact of farming activities on the vegetation of the reserve. The 5,888 hectare forest reserve was divided into three zones for the purpose of this study. They are natural forest (zone 1), plantation (zone 2) and the fallow area (zone 3). Ten plots of 40m x 50m were randomly selected from each zone for enumeration. In addition 100 questionnaires were administered to elicit information on the effects of farming activities on the plant resources of the Olokemeji forest reserve. The inverse of Simpson diversity indices of the three zones showed that zone 1 had 43.5, zone 2, 2.1 and zone 3, 11.8. The very low diversity indices recorded in zones 2 and 3 resulted from the extensive and intensive farming activities as most species in the zones had been cut down during farm clearing. Farming activities in the reserve have resulted in large hectares of impoverished secondary forest, bare and degraded lands, grasslands and plantation of exotic species. About 25 plants useful to the respondents have also been lost due to farming activities.

scholarly journals Long-term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. IX. Simulation of soil carbon and nitrogen pools using CENTURY model

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 206 ◽  
Author(s):  
C. R. Chilcott ◽  
R. C. Dalal ◽  
W. J. Parton ◽  
J. O. Carter ◽  
A. J. King
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Continuous Cultivation ◽  
Carbon Pools ◽  
Century Model ◽  
Nitrogen Mineralisation ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen ◽  
The Impact

Cultivation and cropping of soils results in a decline in soil organic carbon and soil nitrogen, and can lead to reduced crop yields. The CENTURY model was used to simulate the effects of continuous cultivation and cereal cropping on total soil organic matter (C and N), carbon pools, nitrogen mineralisation, and crop yield from 6 locations in southern Queensland. The model was calibrated for each replicate from the original datasets, allowing comparisons for each replicate rather than site averages. The CENTURY model was able to satisfactorily predict the impact of long-term cultivation and cereal cropping on total organic carbon, but was less successful in simulating the different fractions and nitrogen mineralisation. The model firstly over-predicted the initial (pre-cropping) soil carbon and nitrogen concentration of the sites. To account for the unique shrinking and swelling characteristics of the Vertosol soils, the default annual decomposition rates of the slow and passive carbon pools were doubled, and then the model accurately predicted initial conditions. The ability of the model to predict carbon pool fractions varied, demonstrating the difficulty inherent in predicting the size of these conceptual pools. The strength of the model lies in the ability to closely predict the starting soil organic matter conditions, and the ability to predict the impact of clearing, cultivation, fertiliser application, and continuous cropping on total soil carbon and nitrogen.

Phytoplankton Decomposition Process (PDP) Model Dealing with Carbon and Nitrogen Budget on Particulate Organic Matter

2003 ◽  
Vol 36 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Minoru Fujii ◽  
Shinichiro Murashige ◽  
Yuka Ohnishi ◽  
Atsushi Yuzawa ◽  
Hitoshi Miyasaka ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Nitrogen Budget ◽  
Decomposition Process ◽  
Carbon And Nitrogen

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

2020 ◽  
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 ◽  
Natural Forms ◽  
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. 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.

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

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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