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1

Effect of plant Communities and Ecological Parameters on Soil Organic Carbon Stocks in the Mamora Forest, Morocco

Boujraf Amal, Dallahi Youssef, Dahmani Jamila, Orlando Collins Ashianga, Douira Allal

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

128--136

EN

Several studies on the assessment of soil organic carbon (SOC) stocks have been carried out at the global level. However, reliable information on SOC stocks is not readily available at the regional level. In addition, very few studies have assessed the factors responsible for the variation of SOC stocks, in particular the effect of plant communities. For this purpose, the main objective was to analyze the effects of three plant communities and ecological parameters on the SOC stock in the Mamora forest. Specifically, the authors looked to examine the relationships between SOC stock and plant communities and to define the main parameters that directly influence SOC stock. Ten soil profiles with three replications were sampled at each plant community, from which SOC stock was determined. To assess the effect of plant communities on SOC stocks, phytosociological surveys were carried out according to the phytosociological stigma method developed by Braun-Blanquet. The results show that the SOC stocks in cork oak soils are characterized by high variability, with values ranging from 55 t•ha-1 to 95 t•ha-1. Indeed, the findings of this study showed that the SOC stocks fluctuated significantly with plant communities. In addition, SOC stocks were also affected by the interactions between plant communities, the amount of litter and the density of the cork oak stand. These outcomes of this study highlight the critical need to incorporate community-specific carbon values into future carbon sequestration modeling.

2

Effect of Soil Management Practices on the Mineralization of Organic Matter and Quality of Sandy Soils

Kobierski Mirosław, Cieścińska Bogumiła, Cieściński Jacek, Kondratowicz-Maciejewska Krystyna

Journal of Ecological Engineering

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2020

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Vol. 21, nr 4

217--223

EN

The aim of the study was to determine the effect of soil management systems of Brunic Arenosols on the total content of organic carbon and its fraction susceptible to oxidation in comparison with the soils under forests. The samples for study were taken from the humus horizon at the sites located in the forests and soils from little midforest cultivated fields (hunting plots). The agrotechnical treatments increased the content of the plant-available forms of P, K and Mg in the soils of most hunting plots in comparison to the forest soils. In the arable horizon of the hunting plots, t a varied total content of organic carbon and its fraction susceptible to oxidation was found. The cultivation of soil in the hunting plots caused a decrease in the content of total organic carbon as well as its labile and non-labile fraction. In order to evaluate the carbon transformation in the soil of the cultivated plots against the forest (reference soil), the Carbon Management Index (CMI) was used. The decay rate of soil organic matter in a natural forest was lower than in the agricultural fields. A long-term tillage of Brunic Arenosols contributed to the degradation of the pool of organic carbon in sandy-textured soil.

3

Spatial variability and dynamics of soil pH, soil organic carbon and matter content: The case of the Wonji Shoa sugarcane plantation

Dinka Megersa Olumana, Dawit Meseret

Journal of Water and Land Development

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2019

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no. 42

59--66

EN

This study presents the spatial variability and dynamics of soil organic carbon (SOC), soil organic matter (SOM) and soil pH contents at the Wonji Shoa Sugar Estate (WSSE), Ethiopia. Soil samples were collected immediately after the sugarcane was harvested and then analysed for SOC, SOM and pH content using standard procedures. The analysis results showed that the pH value varied between 6.7–8.4 (neutral to moderately alkaline) and 7.3–8.5 (neutral to strongly alkaline) for the top and bottom soil profiles, respectively. The SOM content is in the range of 1.1–6.7% and 0.74–3.3% for the upper and lower soil layers, respectively. Nearly 45% of the samples demonstrated a SOM content below the desirable threshold (<2.1%) in the bottom layer and, hence, inadequate. Moreover, most of the topsoil layer (95%) has an SOM content exceeding the desirable limit and hence is categorized within the normal range. Interestingly, the SOC content showed a spatial variability in both the surface and sub-surface soil layers. A lower SOC and SOM content was found for the sub-soil in the south and southwestern part of the plantation. A further decline in the SOC and SOM content may face the estate if the current waterlogging condition continues in the future for a long period. Overall, the study result emphasizes the need to minimize the pre-harvest burning of sugarcane and action is needed to change the irrigation method to green harvesting to facilitate the SOC retention in the soil and minimize the greenhouse emission effect on the environment, hence improving soil quality in the long-term.

PL

W pracy przedstawiono przestrzenną zmienność i dynamikę węgla organicznego w glebie (SOC), materii organicznej (SOM) i pH na plantacji Wonji Shoa Sugar Estate (WSSE) w Etiopii. Próbki gleby były pobierane bezpośrednio po zbiorze trzciny cukrowej. Analizowano w nich wymienione wyżej składniki według standardowych procedur. Wartość pH zmieniała się od 6,7 do 8,4 w powierzchniowej warstwie gleby i od 7,3 do 8,5 w głębi profilu glebowego. Zawartość materii organicznej wynosiła od 1,1 do 6,7% w górnej i od 0,74 do 3,3% w dolnej warstwie gleby. Około 45% próbek zawierało materię organiczną w ilościach mniejszych niż pożądana (2,1%) w głębszych warstwach gleby. Większość próbek powierzchniowych zawierała materię organiczną w ilościach przekraczających tę granicę, co klasyfikuje te gleby jako normalne. Co ciekawe, zawartość węgla organicznego cechowała zmienność przestrzenna zarówno w powierzchniowych, jak i podpowierzchniowych warstwach gleby. Mniejszą zawartość materii organicznej i węgla organicznego stwierdzono w podpowierzchniowych warstwach gleby z południowej i południowozachodniej części plantacji. Gleby na plantacji mogą doświadczać dalszego spadku zawartości SOC i SOM, jeśli obecne wysycenie gleby wodą będzie występowało w przyszłości. Podsumowując, wyniki badań wskazują na potrzebę minimalizowania opalania trzciny cukrowej przed zbiorem oraz podejmowania działań zmierzających do zmiany metod nawadniania, aby usprawnić retencję węgla organicznego w glebie i łagodzić środowiskowe skutki emisji gazów cieplarnianych, a przez to polepszyć jakość gleb w dłuższej perspektywie czasowej.

4

Soil organic carbon of different decomposition rate and its relation to microbial activity in saline-alkali desert ecosystem

Fang F., Hu Y.-K., Gong Y.-M., Tang H.-P.

Polish Journal of Ecology

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2015

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Vol. 63, nr 1

102--109

EN

Soil microbes’ activity is very important for forming of the nutrient stock and , soil structure, as well as the carbon cycle simulation. This is particularly crucial for deep soil layers. Effect of soil microbes on the rate of accumulation and decomposition of the soil organic carbon (SOC) has been found for different regions. However, it is known still a little on the SOC performance for different decomposition rates and its relation to the microbial activity in the saline-alkali desert ecosystem. Therefore, the main task of our research was investigation of interrelation between the soil organic carbon and microbial carbon (SMC) at different depths in the original saline-alkali Gurbantünggüt Desert. Our results showed in the soil vertical profile, (i) SMC and SOC presented a very significant positive linear correlation (R2 = 0.63, P = 0.0003); (ii) SMC exhibited two obvious changed-interfaces - 20 cm and 80 cm, the SMC at depth of 0–20 cm, 20–80 cm and 80–500 cm was 2.24–3.06, 0.19–0.72, and 0.0017–0.0097 mg kg-1, respectively; (iii) in the depth of 0–20 cm and 20–80 cm, the SMC had highly significant difference (P < 0.0001) and at 20–80 cm and 80–500 cm, significant difference (P = 0.013); (iv) according to the soil division based on the SMC, SOC also had some certain stratification; (v) organic carbon layers can be respectively defined according to different microbial activities as active, inert, and stable organic carbon pool. Therefore, these three kinds of organic carbon pools can be quantitatively measured by analyzing their location at different depths of the soil profile.

5

Changes in soil organic carbon and its density fractions after shrub-planting for desertification control

Liu J.-B., Zhang Y.-Q., Wu B., Qin S.-G., Lai Z.-R.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

205--216

EN

Planting shrubs on sand land and degraded pasture are two main measures for desertification control particularly in northwest China. However, their effects on soil organic carbon (SOC) and its fractions remain uncertain. We assessed the changes in stocks of SOC, light fraction of SOC (LF–SOC) and heavy fraction of SOC (HF–SOC) after planting Artemisia ordosica (AO, 17 years), Astragalus mongolicum (AM, 5 years) and Salix psammophila (SP, 16 years) in sand land and planting Caragana microphylla (CM, 24 years) on degraded pasture. Results show that: 1) after planting AO, AM and SP on sand land, SOC stocks increased by 162.5%, 45.2% and 70.8%, respectively, and LF–SOC accounted for a large proportion in the increased SOC. Dry weights of LF–SOC, rather than carbon concentrations, were higher in shrublands than that in sand land; 2) after planting CM on degraded pasture, SOC stock decreased by 9.3% and all the loss was HF–SOC in 60–100 cm soil layer where both herbaceous fine root biomass (HFRB) and soil water content (SWC) also decreased. The results indicate that planting shrubs can result in an increase of SOC in sand land, whereas that can lead to a decrease of SOC in degraded pasture. The increase of SOC in sand land mainly bases on the accumulation of dry weight of LF–SOC. The loss of SOC in degraded pasture is caused by the decrease of carbon concentrations of HF–SOC, which can be related to the reduction of HFRB and SWC in deep soil layer. Therefore, shrub-planting for desertification control not always improve the quantity and stability of SOC in northwest China.

6

Effect of Nitrogen on Crop Yield as Influenced by Soil pH and Fertilization with Farmyard Manure

Mercik S., Stępień W.

Ecological Chemistry and Engineering. A

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2012

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Vol. 19, nr 1-2

105-112

EN

At the Experimental Station of the Agriculture and Biology Department of Warsaw University of Life Sciences in Skierniewice fertilization experiments have been carried out continuously since 1923, in which the effects of lime, nitrogen, phosphorus, potassium and farmyard manure are studied in a static system with rotation of a few crops. Farmyard manure has been applied on a very acidic soil with a pH of about 4, and on a slightly acidic soil with a pH of 6.0–6.5. This paper describes only the results from combinations with and without nitrogen fertilization in the fields without FYM (since 1923) and with FYM (since 1992). The results presented here include the mean for 4 years yields of potatoes (fertilized with FYM) and grain crops grown in successive years following farmyard manure applications. Included are also the most important properties of the soils sampled in the last year after treatments with farmyard manure. Yield increases resulting from nitrogen fertilization were very high and generally higher in the fields without manure than those with manure. The presence of farmyard manure was found to increase the organic carbon content and total nitrogen content in the soil by about 10 %. This type of fertilizer caused higher increases in yield in the combinations without nitrogen fertilization than in those involving applications of nitrogen.

PL

W Stacji Doświadczalnej Wydziału Rolnictwa i Biologii SGGW w Skierniewicach nieprzerwanie od 1923 r. prowadzone są doświadczenia nawozowe, gdzie bada się działanie wapna, azotu, fosforu, potasu i obornika w układzie statycznym w kilku zmianowaniach roślin. Obornik stosuje się na glebie bardzo kwaśnej o pH około 4 oraz słabo kwaśnej o pH 6,0-6,5. W niniejszej pracy zamieszczono wyniki badań uzyskane tylko z obiektów nawożonych i nienawożonych azotem, na polach bez obornika (od 1923 r.) i z obornikiem (od 1992 r.). Uzyskane dane obejmują średnie z 4 lat plony ziemniaków (nawożonych obornikiem) oraz plony roślin zbożowych uprawianych w kolejnych latach po oborniku. Zamieszczono również najważniejsze właściwości gleb pobranych w ostatnim roku po oborniku. Zwyżki plonów pod wpływem nawożenia azotem były bardzo duże i przeważnie większe na polach bez obornika niż z obornikiem. Obornik zwiększał zawartość węgla organicznego i azotu ogólnego w glebie o około 10 %. Nawóz ten bardziej zwiększał plony na obiektach nienawożonych azotem niż na kombinacjach, gdzie stosowano ten składnik.

7

Specjacja węgla organicznego i wybranych metali ciężkich w glebie torfowo-murszowej

Becher M.

Woda-Środowisko-Obszary Wiejskie

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2011

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T. 11, z. 4

31-42

PL

Celem pracy było określenie zasobów metali ciężkich w glebie organicznej pochodzącej z doliny górnego biegu rzeki Liwiec oraz ich aktualnego i potencjalnego zagrożenia dla środowiska na podstawie analizy sekwencyjnej metali i węgla organicznego. Przeprowadzono sekwencyjną ekstrakcję i wydzielono następujące frakcje operacyjne metali: rozpuszczalna w wodzie (H2O); wymienna (1 mol KNO3·dm-³); metale związane kompleksowe z substancjami humusowymi, z podziałem na kwasy fulwowe i huminowe (0,1 mol Na4P2O7·dm-³); metale mocniej związane przez substancje humusowe, z podziałem na kwasy fulwowe i huminowe (0,1 mol NaOH·dm-³); metale silnie związane z organiczną i mineralną fazą stałą gleby (4 mol HNO3·dm-³); rezydualna (woda królewska). W uzyskanych roztworach oznaczono zawartość węgla (metodą oksydacyjno-miareczkową) oraz zawartość wybranych metali (Fe, Ni, Mn, Cr, Pb, Zn - za pomocą ICP-AES). W poziomach murszu, w stosunku do torfu badanej gleby torfowo-murszowej, stwierdzono mniejszą zawartość materii organicznej i większy jej stopień humifikacji, większą zawartość azotu i mniejszą wartość C:N oraz większą akumulację metali ciężkich. Zawartość analizowanych metali ciężkich uznano za "naturalną" dla gleb organicznych. Analizą sekwencyjną wykazano, że największe ilości metali ciężkich w badanej glebie organicznej występują we frakcji związków kompleksowych z substancjami humusowymi (F3) oraz silnie związanych z organiczną i mineralną fazą stałą gleby (F5); w przypadku chromu we frakcji rezydualnej.

EN

The aim of the work was to study the organic carbon and heavy metal speciation in the Hemic Sapric Histosol from the upper Liwiec River Valley. Sequential analysis distinguished the following fractions: water soluble metals (H2O); exchangeable metals (KNO3); metals complexed with humic and fulvic acid (Na4P2O7) fractions; organically bound metals divided into those bound with humic and fulvic acids (NaOH); metals strongly bound with soil solids (HNO3); and residual fraction. In resulting solutions the content of carbon was determined with the oxidation-titration method and the content of Fe, Ni, Mn, Cr, Pb, Zn - using ICP-AES. Smaller content of organic matter, higher degree of humification, higher content of nitrogen and lower C:N ratio and higher accumulation of heavy metals were found in muck horizons as compared with peat horizons. The total content of analysed metals was "natural" for organic soils. Most heavy metals were found in humic complexes and in fractions strongly bound with soil solids. Most of chromium was found in residual fraction.

8

Warming effects on plant growth, soil nutrients, microbial biomass and soil enzymes activities of two alpine meadows in Tibetan Plateau

Li N., Wang G., Gao Y., Wang J.

Polish Journal of Ecology

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2011

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Vol. 59, nr 1

25-32

EN

The aim of this study was to assess initial effects of warming on the plant growth, soil nutrient contents, microbial biomass and enzyme activities of two most widespread ecosystem types: swamp meadow (deep soil, high water content) and alpine meadow (poor soil, low water content), in the hinterland of the Qinghai-Tibet Plateau (altitude 4600.4800 m a.s.l.) The temperature of air and upper soil layer was passively enhanced using open-top chambers (OTCs) (50 cm high with 60 cm at opening and constructed of 6 mm thick translucent synthetic glass) from 2006 to 2008. The use of OTCs clearly raised temperature and decreased soil moisture. In warmed plots, monthly mean air temperature was increased by 2.10[degrees]C and 2.28[degrees]C, soil moisture of 20 cm soil layer was decreased by 2.5% and 3.9% in alpine meadow and swamp meadow, respectively. Plant biomass significantly increased by 31% in alpine meadow and 67% in swamp meadow. Warming also affected soil microbial biomass C and N at both meadows. In swamp meadow, warming caused the decrease of soil organic carbon and total nitrogen in 0-5 cm layer and an increase in 5-20 cm. While in alpine meadow, these soil parameters increased in 0-5 cm layer and decreased in 5-20 cm layer. The effects of warming on enzyme activities differed depending on the enzyme and the meadow ecosystem. In general, enzyme activities were higher in the upper soil layers (0-5 cm) than in the lower soil layers (5-20 cm). The experiment results exhibited that warming improved the soil biochemical and microbiological conditions in high- mountain meadows, at least in the short term.

9

Earthworms (Lumbricidae) as bioindicators : the relationship between in-soil and in-tissue heavy metal content

Tischer S.

Polish Journal of Ecology

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2009

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Vol. 57, nr 3

513-523

EN

The heavy metal (Cd, Zn, Cu, Pb, Ni, Cr) accumulation in earthworms was measured and evaluated on 84 differently managed and polluted sites (field, grassland, deciduous forest, coniferous forest, alluvial sites, mine spoil) together with selected soil properties, like pH and C[org]-contents. The uptake of heavy metals by the earthworms was correlated with in-soil metal amounts and it showed a considerable variation between land use types and the individual lumbricid species. An important positive correlation was determined between in-tissue contents of earthworms and in-soil contents for all studied heavy metals: Cd (R[^2] = 0.72), Cu (R[^2] = 0.65), Cr (R[^2] = 0.54), Pb (R[^2] = 0.51), Zn (R[^2] = 0.47), Ni (R[^2] = 0.45). Mostly Cd and Zn are accumulated by earthworms. The uptake of Cd and Zn by epigeic earthworms is stronger than by other endogeic and anecic species. The highest metal amounts of Cd were accumulated in the following species: Aporrectodea caliginosa (Savigny) (18 mg kg[^-1] dw) Lumbricus castaneus (Savigny) (17 mg kg[^-1] dw), Octolasion cyaneum (Savigny) (17 mg kg[^-1] dw), Lumbricus rubellus (Hoffmeister) (14 mg kg[^1] dw). The highest uptake of Zn was found for the species: L. castaneus (623 mg kg[^-1] dw), Lumbricus terrestris (Linnaeus) (433 mg kg[^-1] dw), A. caliginosa (416 mg kg[^-1] dw), and L. rubellus (339 mg kg[^-1] dw). The lowest contents of Cd (3 mg kg[^-1]dw) were calculated for Aporrectodea longa (Ude) and for Zn - Allolobophora chlorotica (Savigny) (168 mg kg[^1-] dw). Transfer ratios (TR) (ratio of in-soil heavy metal content to the in-tissue metal content in earthworms) ranged for Cd - from 6 in alluvial forest sites to 64 in coniferous forest sites and for Zn - from 2 in alluvial grassland to 12 in coniferous forest. Cd and Zn are more strongly taken up by the epigeic species like Dendrobaena octaedra (Savigny) (TR: Cd = 47, Zn = 8), L. rubellus (TR: Cd = 21, Zn = 5), and L. castaneus (TR: Cd = 12, Zn = 5) than by the other endogeic and anecic species, with TR values accounted from 9 to 21 for Cd and 2 to 5 for Zn, respectively. For risk assessment of habitats cadmium is the more important heavy metal due to its high transfer rates into the tissues of earthworms.

10

Lumbricidae communities in soil monitoring sites differently managed and polluted with heavy metals

Tischer S.

Polish Journal of Ecology

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2008

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Vol. 56, nr 4

635-646

EN

Species composition, density and biomass of earthworms were studied on 84 differently managed and polluted sites (field, grassland, deciduous forest, coniferous forest, alluvial sites and mine spoil). All these sites are constantly monitored since a decade. In 13 sites amounts of heavy metals increased from: Cd - 3 to 6 mg kg[^-1], Zn - 303 to 606 mg kg[^-1], Pb - 95 to 317 mg kg[^-1], Ni - 31 to 55 mg kg[^-1], Cr - 58 to 80 mg kg[^-1], and Cu - 59 to 114 mg kg[^-1] soil, that is up to 2000, 880, 1090, 295, 320, and 520% higher, respectively, than in unpolluted field sites. Results show that metal pollution is not a dominating factor determining the species diversity and densities of earthworms. Remarkable differences in the distribution of ecological groups were found between biotope types. The endogeic species (Aporrectodea caliginosa Savigny, Aporrectodea rosea Savigny, Allolobophora chlorotica Savigny, Octolasion cyaneum Savigny) dominate in field and grassland habitats. The anecic species (Lumbricus terrestris L., Aporrectodea longa Ude), however, appear mostly in grassland. Epigeic species (Lumbricus rubellus Hoffmeister, Lumbricus castaneus Savigny, Dendrobaena octaedra Savigny) are found exclusively (in addition to the other two life forms) in grassland and the forest habitats. Differences in earthworm biomass between monitoring sites are not related to ecological risk assessment. These differences may be largely dependant on soil properties e.g. pH and organic matter. A matrix with the ecological requirements of earthworm species was developed.