ArticlePDF Available

IMPACT OF EARTHWORMS OF DIFFERENT MORPHO-ECOLOGICAL GROUPS ON CARBON ACCUMULATION IN FOREST SOILS

Authors:

Abstract and Figures

To date, forest ecology has not made any clear conclusions regarding the impact of large saprophagous invertebrates such as earthworms on soil carbon dynamics. Some authors claim that earthworm activities result in decreased carbon accumulation. Other studies show that earthworms contribute to soil carbon accumulation. At the same time, many studies do not take into account the differences between trophic and digging activity of different morpho-ecological groups of earthworms in different soil horizons. The objective of this study was to carry out differentiated assessment of the impact of different morpho-ecological groups of earthworms on carbon accumulation and correspondent soil parameters (nitrogen content and С/N ratio) throughout the change in forest succession status. Field operations were performed in the spring and summer of 2016 and 2018 in three regions: Bryansk Oblast (Bryansk Forest reserve), Moscow Oblast (Moskva–Oka plain, Valuyevsky urban forest) and Northwest Caucasus (Krasnodar Krai, Apsheron forestry; Republic of Adygeya, Caucasian Biosphere Reserve). Three main stages of coniferous-broadleaf forest restoration after clear cuttings were identified in each region. Three test plots 50х50 m were allocated for each stage; geobotanical and soil descriptions as well as earthworm registration were carried out on each plot. It was found out that during the change in forest succession status the species composition and the set of morpho-ecological groups of earthworms became more complicated, but there was no successive replacement of any groups with others. Ambiguous effects of different morpho-ecological groups of earthworms on carbon accumulation in forest soils were revealed. Negative correlation was found between the total biomass of earthworms feeding on the soil surface (epigeic, epi-endogeic and anecic species) and litter store. In the humus horizon, the biomass of epi-endogeic species was positively correlated with the content of carbon. C/N ratio and nitrogen content are unidirectionally correlated with the biomass of earthworms in the horizons of their activity: with an increase in the biomass of earthworms of different morpho-ecological groups, the C/N ratio decreases, and the nitrogen content increases.
Content may be subject to copyright.
A preview of the PDF is not available
... Earthworms are typically classified into two morpho-ecological types: those feeding on the soil surface and those feeding on humus (Perel 1979)-or epigeic, anecic, andendogeic, andcombinations thereof (Bouche 1977). Worms belonging to the former morpho-ecological type are capable of increasing the content of humus (Perel et al. 1966) and carbon in the soil (Huang et al. 2020;Geraskina 2021). Worms that consume humus may either reduce soil carbon or have no effect on soil carbon (Huang et al. 2020;Geraskina 2021). ...
... Worms belonging to the former morpho-ecological type are capable of increasing the content of humus (Perel et al. 1966) and carbon in the soil (Huang et al. 2020;Geraskina 2021). Worms that consume humus may either reduce soil carbon or have no effect on soil carbon (Huang et al. 2020;Geraskina 2021). At the same time, even worms belonging to the same (Andriuzzi et al. 2016). ...
... This variant included worms of three ecological groups, i.e., epigeic, epi-endogeic, and endogeic. Apparently, this combination is most favorable for the accumulation of humus in soils, which is supported by a number of publications (Huang et al 2020;Geraskina 2021). Could the spread of invasive earthworm species in the forest-steppe of Western Siberia lead to a decrease in humus, which is noted in the works of Reinhard (2009), Demin and Eremina (2022)? ...
Chapter
Full-text available
Since the second half of the twentieth century, significant losses of humus have been noted in the soils of the south of Western Siberia. This period also became favorable for the spread of invasive earthworm species in both agrocenoses and natural ecosystems as a result of soil plowing and climate change. In this study, we aim to determine whether earthworm invasions in the south of Western Siberia could alter the amount of humus and further aggravate soil fertility. To this end, we analyzed soil samples from field experiments in mesocosms. Earthworm invasions in Western Siberia were simulated in experiments on meadow-chernozem soils. We studied the influence of the native species Eisenia nordenskioldi and invasive species E. ventripappilata, E. nana and their cohabitation for 92 days on soil parameters. A significant effect of invasive species and all combinations of earthworms on the amount of soil humus was identified. E. ventripappilata was found to have the greatest impact on soil humus. This species contributed to a decrease in the amount of humus. Thus, earthworm invasions in the south of Western Siberia may lead to even greater soil degradation and soil fertility loss.
... It is important to note that the studies did not always take into account the belonging of worms to different functional groups, which could be the reason for different conclusions. However, the belonging of earthworms to individual groups functioning in different soil horizons and having different effects on the soil's organic matter is of great importance [21][22][23]. To give an unambiguous explanation of how earthworms affect carbon accumulation in soil, it is necessary to take into account both their combined influence and the influence of individual functional groups. ...
... The modern forest cover of BP is represented by secondary communities, and among them, pine forests (BP1, 3 plots) and pine-broadleaf (BP2, 3 plots) forests are widely distributed in the autonomous positions of landscape in the study area [34][35][36] The detailed physico-geographical, geobotanical characteristics of all objects of study, as well as a description of macrosaprophages and the physicochemical characteristics of soils, have been also presented earlier [23,[36][37][38]. ...
... When comparing litter quality, it was found (Table S2) that BS varied slightly, from 94% in NC1 forests to 92% in the NC3 forests. The lowest litter C/N ratio (23) was found in NC1 forests. The pH values and N contents in the L-layer of all forests were comparable (Table S2). ...
Article
Full-text available
Linking vegetation, soil biota, and soil carbon stocks in forests has a high predictive value. The specific aim of this study was to identify the relationships between vegetation, earthworms, and soil carbon stocks in nine types of forests dominating autonomous landscape positions in a coniferous–broadleaf forest zone of the European part of Russia. Mountain forests were selected in the Northwest Caucasus, while plain forests were selected in Bryansk Polesie and on the Moskva-Oka plain. One-way analysis of variance (ANOVA) and v-tests were used to assess the impact of different factors on soil C stocks. To assess the contribution of vegetation, litter quality, and earthworms to variation of carbon stocks in organic (FH-layer) and mineral layer (0–50 cm), the method of hierarchical partitioning was performed. The highest C stocks in the organic horizons were associated with the low-quality litter, i.e., with a low base saturation, high acidity, and wide C/N ratio. The highest soil C stocks in the mineral layers were found in mixed forests with the highest richness of plant species, producing litterfall of different quality. The С stock in the organic horizon was negatively related to the biomass of worms that process the litter, while the carbon stock in the mineral layers was positively related to the biomass of worms whose life activity is related to the mineral layers. These findings demonstrated the substantial influence of plants producing a litter of different quality, and of earthworms, belonging to different functional groups, on soil С stocks in coniferous–broadleaf forests.
Article
Фундаментальные и прикладные исследования почв южных регионов Европейской части России по проблеме борьбы с опустыниванием привели к расширению теоретической базы оценки изменений в свойствах почв и их комбинаций, оказывающих влияние на ресурсоведческий потенциал почвенного покрова. По результатам проведенных исследований представляется возможность определить ресурсный потенциал создаваемого при формировании временных (сезонных, межсезонных) функций, способствующих формированию потенциала продукционных ресурсов. Речь идет о весеннем, весеннелетнем комбинациях свойств почв, формирующихся под влиянием умеренного потепления и стабильного увлажнения К = 0,5–0,6 в течение 50–60 дней. В засушливых условиях Терско–Кумской низменности этот период времени является определяющим фактором формирования новых комбинаций в свойствах почв на уровне существующих классификационных единиц. Возникла необходимость выявления разнообразия растений и их урожайности в условиях временно-функционирующих свойств почв. Основная цель – выявление определяющего фактора запасов аккумулированной влаги в слое 0–20 см, составляющей 25–30% полевой влагоемкости. Этот период охватывает диапазон времени, когда проходят фазы развития растений и накопления влаги, начиная с первой декады апреля до конца мая. При этом решается задача – совершенствование классических методов земледелия аридных условий выращиванием кормовых культур короткой вегетацией на почвах, подверженных опустыниванию в различной степени. Кроме того, раскрываются перспективы использования природных факторов возрождения земель, подверженных деградации аридного климатического пояса. Новизна исследуемого явления по ресурсоведческой части позволяет рекомендовать проведение НИР по выявлению ареалов временно-функционирующих комбинаций почв, получивших широкое распространение в южных регионах Европейской части России
Article
Full-text available
The paper provides a brief analysis of well-known works containing evidence of carbon accumulation in old-growth forests. The analysis of the current state of the problem allows us to conclude that old-growth forests continue to accumulate carbon. A map of old-growth forests in Russia, identified on the basis of tree age higher than 200 years, using remote sensing data, is presented, and estimates of carbon pools in these forests are discussed. According to the estimates obtained, the area of old-growth forests in Russia was 163 mln ha as of 2021, and carbon stocks in phytomass reached 7.33 bln t, with the contribution of larch forests and larch woodlands of 86%. It is shown that the most important cause of uncertainties in the estimates of carbon cycles in old-growth forests is the uncertainty of the concept of “old-growth forests.” The mosaic structure of forests, that is, the high horizontal structural diversity, contributes to the accumulation of nitrogen and carbon in soils due to the creation of functioning conditions for various plant species, including light-loving ones, and, accordingly, due to the presence of litter of different quality, which is important for soil biota. Old-growth mosaic forests in Moskvoretsko-Oka Plain accumulated more nitrogen and carbon in soils than forests at an earlier stage of succession with a low mosaicity (in average 80 t/ha versus 60 t/ha in the 30-cm layer). The old-growth fir-beech dead-cover forests of the Northwestern Caucasus, whose tree stand is characterized by the highest productivity in Russia and Europe and high carbon reserves in the tree stand, are characterized by low carbon stock in soils compared to forests at an earlier stage of development (in average 58 t/ha versus 99 t/ha in 30-cm layer). This is due to the low quality of beech and fir litter and the absence of a pronounced window mosaic, which prevents the colonization of light-loving plant species, including with a high quality of litter. It is shown that, along with microorganisms, it is necessary to take into account such agents of decomposition, mineralization and humification as earthworms, which play a key role in carbon cycles. Carbon stock in the litter of northern taiga spruce forests is an order of magnitude higher than in coniferous-broad-leaved forests; in the litter and in the mineral layer of 0–30 cm, the carbon reserves under the crowns of spruce trees for about 200 years turned out to be significantly higher than in the spaces between the crowns, exceeding 80 t/ha.
Chapter
Full-text available
This chapter synthesizes information on the effects of earthworms on soil systems at scales longer than 1 year, and earthworm behavior that may affect these processes is detailed.
Article
Full-text available
A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community composition. Furthermore, because earthworm invasion can involve a predictable shift in community structure along invasion fronts or through time, the community dynamics of invasion are important in predicting the spatial and temporal effects of earthworm invasion on litter decomposition, especially at later stages of decay.
Article
Few earthworms are present in production agricultural fields in the semi-arid plains of Colorado, where earthworm populations may be constrained by limited water and/or organic matter resources. We conducted a 12-week laboratory incubation study to determine the potential of a non-native endogeic earthworm (Aporrectodea caliginosa) to survive in a low-organic matter Colorado soil (1.4% organic C content), supplemented with or without biosolids, and to determine the effects of A. caliginosa on soil microbial biomass and soil nutrient availability. A factorial design with three main effects of A. caliginosa, biosolids addition, and time was used. Data was collected through destructively sampling at one, two, four, eight, and twelve weeks. During the 12-week study, 97.5% of the worms in the soil survived, and the survival of the earthworms was not significantly affected by the addition of biosolids. The addition of biosolids, however, did significantly reduce the gain in mass of the earthworms (8% mass gain compared to 18% in soil without biosolids). The presence of A. caliginosa significantly increased soil NH4-N, and NO3-N concentrations by 31% and 4%, respectively, which was less than the six fold increases in both soil NH4-N, and NO3-N concentrations supplied from biosolids. Microbial biomass carbon was not affected by A. caliginosa, but microbial biomass N was affected by an earthworm × biosolids interaction at week 1 and 12. We concluded that A. caliginosa can survive in a low-organic matter Colorado soil under optimal moisture content and that once established, A. caliginosa can provide modest increases in inorganic N availability to crops Colorado agroecosystems.
Article
Major known fractions of soil nitrogen are amino nitrogen (proteins, peptides), polymers of amino sugars, and NH4 + fixed in interlayers of 2:1 minerals. Only a small percentage of the total soil organic N is easily mineralizable and contributes to the pool of mineral soil N. Predominant sources of mineralization are amino-N and polymers of amino sugars present in the soil microbial biomass. Influx into this pool occurs with the application of organic matter (green manure, straw), organic carbon released by plant roots, N2 assimilation by leguminous species and inorganic nitrogen. Microbial metabolization of green manure proteins results in a partial mineralization of the applied organic N, microbial metabolization of straw in the assimilation (immobilization) of inorganic nitrogen.Microbial biomass is characterized by a narrow C/N ratio (proteins, peptidoglycans, polymers of amino sugars). Its metabolization therefore is associated with a partial mineralization of the attacked organic nitrogen compounds. Nitrogen mineralization consists of a sequence of enzymatic processes for which the living microbial biomass provides the enzymes and the dead microbial biomass the substrate.
Article
The effects of endogeic earthworms on the soil organic matter (SOM) dynamics of moist tropical soils are: (i) a sharp increase of mineralization during digestion; (ii) the presence in fresh casts of large amounts of mineral nutrients which are reorganized in microbial biomass at the scale of days to weeks depending on soil properties; (iii) a subsequent blocking of mineralization at the scale of months to years in the compact structure of ageing casts (i.e. older than 1–2 weeks).It is hypothesized that, at the larger scale of soil profile and years, activities of earthworms will result in an acceleration of SOM turnover and the accumulation of labile rather than passive organic matter.
Akkumuljacija ugleroda v lesnyh pochvah i sukcessionnyj status lesov (Carbon accumulation in forest soils and forest succession status
  • N V Lukina
  • E V Tihonova
  • N E Shevchenko
  • A V Gornov
  • A I Kuznecova
  • V N Shanin
Lukina N.V., Tihonova E.V., Shevchenko N.E., Gornov A.V., Kuznecova A.I., … & Shanin V.N., Akkumuljacija ugleroda v lesnyh pochvah i sukcessionnyj status lesov (Carbon accumulation in forest soils and forest succession status), N.V. Lukinа (Ed.), Moscow: KMK, 2018, 232 p.