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SOIL ORGANISMS

2019 Issues

Issue 91 (3) December

Clitellata, Enchytraeidae, Earthworm, Climate change, International collaboration

Content

Fernando T. Maestre & Nico Eisenhauer
Recommendations for establishing global collaborative networks in soil ecology

Rüdiger M. Schmelz, Mårten J. Klinth, Christina Chalkia, Pelagia Anastasiadou & Evangelia Vavoulidou
Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus

Jiří Schlaghamersky & Miloslav Devetter
Enchytraeid assemblages at the foot of a talus slope in Skansbukta on the Arctic island of Spitsbergen

Sylvain Coq & Sébastien Ibanez
Soil fauna contribution to winter decomposition in subalpine grasslands

Jaswinder Singh, Martin Schädler, Wilian Demetrio, George G. Brown & Nico Eisenhauer
Climate change effects on earthworms – a review

Gabriel R. Smith, Thomas W. Crowther, Nico Eisenhauer & Johan van den Hoogen
Building a global database of soil microbial biomass and function: a call for collaboration
A CALL FOR COLLABORATION

All articles

Recommendations for establishing global collaborative networks in soil ecology

Fernando T. Maestre & Nico Eisenhauer

Title: Recommendations for establishing global collaborative networks in soil ecology

Abstract

The complexity and transnational nature of environmental issues our societies are facing, and the need to build scientific capacity building in many regions of the world, require the establishment of global collaborative research networks that include a diverse representation of scientists from multiple geographical, cultural and socio-economical backgrounds. This topic is currently gaining relevance in the field of soil ecology, as awareness is increasing that recognizing, addressing, and predicting the changes that soils are facing requires global collaboration. However, the setup, management and operation of research networks imply multiple tasks and challenges that need to be carefully considered. While major issues related to the setup of such networks in ecology have already been described in the literature, here we focus on aspects that are important to make them truly global and inclusive. For doing so, we introduce a series of recommendations to successfully develop research networks that: i) explore ecological questions requiring data with a global coverage and ii) foster the participation of scientists who have been traditionally underrepresented in international research collaborations. These recommendations, which are based on our own experience, also provide practical advice to anyone aiming to initiate (or join) a global collaborative research network to the mutual benefit of all contributors.

Keywords: international collaboration, environmental issues, distributed experiments, distributed observations

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DOI 10.25674/so91iss3pp73

Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus

Rüdiger M. Schmelz, Mårten J. Klinth, Christina Chalkia, Pelagia Anastasiadou & Evangelia Vavoulidou

Title: Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus

Abstract 

A new species of enchytraeids with peculiar characters is described, Enchytraeus demutatus sp. nov. The species differs from all known species of Enchytraeus in features of the oesophageal appendages and the male efferent apparati. The oesophageal appendages insert ventro-laterally below the pharyngeal pad and not dorsally behind the pad, as is usual in the genus; furthermore, their histology is different. The male efferent apparati have each an unusually wide and short vas deferens, and accessory glands are attached to the inner surface of the male glandular bulb, in close vicinity to the male pore. The remaining characters agree with the genus diagnosis of Enchytraeus, notably the presence of testis sacs and oesophageal appendages. The bisetose worms are about 5 mm long and 0.2–0.3 mm wide. The peculiarities of the oesophageal appendages raised the possibility to place the species in a new genus. DNA sequencing was performed to provide molecular identifiers and to assess the generic placement of the species. The molecular phylogenetic analysis, based on a concatenation of the six genetic markers 12S, 16S, 18S, 28S, COI and H3 placed E. demutatus inside the well-supported (PP  =  0.99) Enchytraeus clade and not outside, hence the new species is to be considered a member of Enchytraeus. The tree includes species that cover a wide range of the morphological diversity in Enchytraeus; here E. demutatus sp. nov. groups with a sub-branch that includes the other bisetose species, also the fragmenting ones, but also one species with 3 chaetae per bundle; whereas species of the E. buchholzi-group and the E. albidus-group, respectively, form clades of their own. E. demutatus sp. nov. was found in soil samples derived from a tomato field of a private greenhouse farm in the regional division of Ilia, West Greece, together with abundant E. bigeminus.

Keywords: Clitellata, soil fauna, soil biodiversity, taxonomy

DOI 10.25674/so91iss3pp87

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Enchytraeid assemblages at the foot of a talus slope in Skansbukta on the Arctic island of Spitsbergen

Jiří Schlaghamersky & Miloslav Devetter

Title: Enchytraeid assemblages at the foot of a talus slope in Skansbukta on the Arctic island of Spitsbergen

Abstract

Enchytraeids are an important component of Arctic ecosystems both as decomposers and part of the foodchain. Compared to other regions of the High Arctic, the enchytraeid fauna of Spitsbergen and some other islands of the Svalbard archipelago have been explored rather well but we still lack information from many areas and specific habitats. In August 2018, potworms (Annelida: Clitellata: Enchytraeidae) were sampled on the lower portion of a talus slope and in the flat area between this slope and the beach of Skansbukta, a bay of the Isfjord(en) on the western coast of Spitsbergen. Objectives were to compare assemblage composition and densities of close-by sites differing in their environmental characteristics, to provide faunistic data for a little explored area within Spitsbergen, and to clarify the true identity of Marionina argentea s.l., which had been found here previously. Six taxa on species level were recorded, including a Mesenchytraeus species of uncertain identity. Using morphological and molecular characters, Marionina argentea s.l. was shown to be M. mimula, a species described rather recently from Ireland and Sweden and hitherto not known from the Svalbard archipelago. This species dominated the moist flat area, substantially contributing to the higher enchytraeid density of ca 10 000 individuals/m2 compared to less than 3 000 ind./m2 on the lower slope. In the flat area ca 70 % of enchytraeids were present in the uppermost 3 cm layer consisting of mainly live mosses, whereas on the lower slope the distribution of individuals between the 0–3 and 3−6 cm layers was very balanced but no individuals occurred in greater depth, though there was no apparent change in the character of the moss-derived organic soil with depth.

Keywords: Soil Animals, Svalbard, Isfjorden, Enchytraeidae, Marionina mimula

DOI 10.25674/so91iss3pp97

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Soil fauna contribution to winter decomposition in subalpine grasslands

Sylvain Coq & Sébastien Ibanez

Title: Soil fauna contribution to winter decomposition in subalpine grasslands

Abstract

Cold biomes significantly contribute to the global carbon cycle, and decomposition in these ecosystems is expected to be affected by climatic change. Modifications of snow cover patterns are expected to affect litter decomposition, but the underlying mechanisms remain unclear. In this study, we investigated whether soil meso- and microfauna significantly contribute to wintertime decomposition. Using litterbags with two mesh sizes (68 µm and 1500 µm), we found that small mesh litterbags reduced winter decomposition in the field by 3.4 % for Patzkea paniculata litter and by 18.9 % for Dactylis glomerata litter, indicating a significant contribution of soil meso- and microfauna to litter decomposition under the snowpack. Whereas previous studies showed that winter decomposition was not related to the soil fauna community, our results suggest that this community, and its possible alteration by climate change, may impact litter decomposition and carbon dynamics in cold biomes.

Keywords: detritivorous fauna, Patzkea paniculata, Dactylis glomerata, litterbags, mesh size

DOI 10.25674/so91iss3pp107

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Climate change effects on earthworms – a review

Jaswinder Singh, Martin Schädler, Wilian Demetrio, George G. Brown & Nico Eisenhauer

Climate change effects on earthworms – a review

Abstract

Climate change can have a plethora of effects on organisms above and below the ground in terrestrial ecosystems. Given the tremendous biodiversity in the soil and the many ecosystem functions governed by soil organisms, the drivers of soil biodiversity have received increasing attention. Various climatic factors like temperature, precipitation, soil moisture, as well as extreme climate events like drought and flood have been shown to alter the composition and functioning of communities in the soil. Earthworms are important ecosystem engineers in the soils of temperate and tropical climates and play crucial roles for many ecosystem services, including decomposition, nutrient cycling, and crop yield. Here, we review the published literature on climate change effects on earthworm communities and activity. In general, we find highly species- and ecological group-specific responses to climate change, which are likely to result in altered earthworm community composition in future ecosystems. Earthworm activity, abundance, and biomass tend to increase with increasing temperature at sufficiently high soil water content, while climate extremes like drought and flooding have deleterious effects. Changing climate conditions may facilitate the invasion of earthworms at higher latitudes and altitudes, while dryer and warmer conditions may limit earthworm performance in other regions of the world. The present summary of available information provides a first baseline for predictions of future earthworm distribution. It also reveals the shortage of studies on interacting effects of multiple global change effects on earthworms, such as potential context-dependent effects of climate change at different soil pollution levels and across ecosystem types.

Keywords: Biodiversity, Climate change, Climate drivers, Cocoons, Earthworm invasions, Soil organisms

DOI 10.25674/so91iss3pp114

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Building a global database of soil microbial biomass and function: a call for collaboration
A CALL FOR COLLABORATION

Gabriel R. Smith, Thomas W. Crowther, Nico Eisenhauer & Johan van den Hoogen

Title: Building a global database of soil microbial biomass and function: a call for collaboration
A CALL FOR COLLABORATION

Abstract

Global analyses are emerging as valuable complements to local and regional scale studies in ecology and are useful for examining many of the major environmental issues that we face today. Soil ecology has significantly benefited from these developments, with recent syntheses unearthing interesting, unexpected biogeographic patterns in belowground biotic communities. However, some questions still remain unanswered, and the accuracy of these studies is inevitably limited by the extent of the data they draw upon. This is a particular problem in global ecology because most datasets used exhibit geographic bias in sample distribution. Here, we work towards addressing this problem with an open call for collaboration on a planned global analysis of soil phospholipid fatty acid and potential enzyme activity measurements. We summarize the current extent of our dataset, outline the planned analyses, and provide information for prospective collaborators who would like to contribute or learn more.

DOI 10.25674/so91iss3pp140

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Issue 91 (2) August

Open access; Clitellata: Enchytraeidae; trophic niches

Content

Nico Eisenhauer & Willi E.R. Xylander
SOIL ORGANISMS – an international open access journal on the taxonomic and functional biodiversity in the soil
 
Svante Martinsson
A morphology-based identification key to the Cognettia species of the world  (Clitellata: Enchytraeidae)
 
Odette González Macé, Anne Ebeling, Nico Eisenhauer, Simone Cesarz & Stefan Scheu
Variations in trophic niches of generalist predators with plant community composition as indicated by stable isotopes and fatty acids
  
Simone Cesarz, Annika Eva Schulz, Rémy Beugnon & Nico Eisenhauer
Testing soil nematode extraction efficiency using different variations of the Baermann-funnel method

All articles

SOIL ORGANISMS – an international open access journal on the taxonomic and functional biodiversity in the soil

Nico Eisenhauer & Willi E.R. Xylander

Title: SOIL ORGANISMS – an international open access journal on the taxonomic and functional biodiversity in the soil

Abstract

Biodiversity change and the identification of the underlying drivers are in the focus of ecological research and public and political debate (IPBES 2019). Soil biodiversity has thus far rarely entered this discussion and analyses (Cameron et al. 2018), and substantial gaps in soil biodiversity and function data exist (Cameron et al. 2019). Furthermore, we know exceptionally little about temporal changes in soil biodiversity (Phillips et al. 2017), although soil biodiversity is thought to be essential for critical ecosystem functions and services (Bardgett & van der Putten 2014, Wall et al. 2015) but threatened by anthropogenic impacts (Veresoglou et al. 2015). At the same time, taxonomic expertise of soil biodiversity may be at risk, while novel molecular information still needs to be linked to species and functions (Geiger et al. 2016).

Keywords: SOIL ORGANISMS, Open Access

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DOI 10.25674/so91200

 

A morphology-based identification key to the Cognettia species of the world  (Clitellata: Enchytraeidae)

Svante Martinsson

Title: A morphology-based identification key to the Cognettia species of the world (Clitellata: Enchytraeidae)

Abstract 

Morphological characters for identification of Cognettia species are presented both as a dichotomous key and in table form. Focus is on non-sexual characters, as many species reproduce mainly asexually, and sexually mature individuals can be rare.

Keywords: Annelida | Chamaedrilus

DOI 10.25674/so91103

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Variations in trophic niches of generalist predators with plant community composition as indicated by stable isotopes and fatty acids

Odette González Macé, Anne Ebeling, Nico Eisenhauer, Simone Cesarz & Stefan Scheu

Title: Variations in trophic niches of generalist predators with plant community composition as indicated by stable isotopes and fatty acids

Abstract

Arthropods are a dominant component of biodiversity in terrestrial ecosystems. They are considered pest control agents and drive important ecosystem processes like nutrient cycling. However, such ecosystem effects of arthropods may depend on the environmental context influencing nutrition and behaviour. In the framework of a grassland plant diversity experiment (Jena Experiment), we used stable isotope and fatty acid analysis to investigate intraspecific variations in the diet of two of the most abundant predatory arthropods in grasslands: the ground beetle Harpalus rufipes and the wolf spider Trochosa ruricola. The results show that the diet of H. rufipes varied significantly with plant species diversity, consuming more plant material, probably seeds, at high diversity plots, and in the presence of grasses and small herbs. By contrast, in presence of legumes H. rufipes consumed more animal prey, presumably aphids and/or collembolans. Compared to H. rufipes, the diet of T. ruricola consisted of animal prey only and varied mainly with body size, with larger individuals occupying higher trophic position in the food web. Moreover, the diet of T. ruricola changed in response to summer flooding two months before sampling. Presumably, the availability of secondary decomposer prey as well as intraguild prey was increased in severely flooded plots. As both species are considered pest control agents, the results underline the importance of plant diversity and the composition of plant communities for biological pest control.

Keywords: spider, Lycosidae, beetle, Carabidae, grassland, diet

DOI 10.25674/so91204

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Testing soil nematode extraction efficiency using different variations of the Baermann-funnel method

Simone Cesarz, Annika Eva Schulz, Rémy Beugnon & Nico Eisenhauer

Title: Testing soil nematode extraction efficiency using different variations of the Baermann-funnel method

Abstract

Nematodes are increasingly used as powerful bioindicators of soil food web composition and functioning in ecological
studies. Todays’ ecological research aims to investigate not only local relationships but global patterns, which requires consistent methodology across locations. Thus, a common and easy extraction protocol of soil nematodes is needed. In this study, we present a detailed protocol of the Baermann-funnel method and highlight how different soil pre-treatments and equipment (soil type, soil height, sieving, and filter type) can affect extraction efficiency and community composition by using natural nematode communities. We found that highest nematode extraction efficiency was achieved using lowest soil height as indicated by the thickness of the soil sample in the extractor (1, 2, or 4 cm soil height) in combination with soil sieving (instead of no sieving), and by using milk filters (instead of paper towels). PCA at the family level revealed that different pre-treatments significantly affected nematode community composition. Increasing the height of the soil sample by adding more soil increased the proportion of larger-sized nematodes likely because those are able to overcome long distances but selected against small nematodes. Sieving is suggested to break up soil aggregates and, therefore, facilitate moving in general. Interestingly, sieving did not negatively affect larger nematodes that are supposed to have a higher probability of getting bruised during sieving but, even if not significant, tended to yield more extracted nematodes than no sieving. We therefore recommend to use small heights of sieved soil with milk filter to extract free-living soil nematodes with the Baermann-funnel method. The present study shows that variations in the extraction protocol can alter the total density and community composition of extracted nematodes and provides recommendations for an efficient and standardized approach in future studies. Having a simple, cheap, and standardized extraction protocol can facilitate the assessment of soil biodiversity in global contexts.

Keywords: soil organisms, comparability, reproducibility, extraction methods

DOI 10.25674/so91201

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Issue 91 (1) April

Actinotrichida, Oribatida, Trhypochthoniidae, Myriapoda, Chilopoda

Content

Obituary Prof. Dr. Wolfram Dunger (PDF)

Maria Cleide de Mendonça & Tatiana Christina da Silveira
A peculiar new species of Scutisotoma Bagnall, 1949 (Collembola: Isotomidae) from Brazil

Bernhard Seifert
A taxonomic revision of the members of the Camponotus lateralis (Hymenoptera: Formicidae) from Europe, Asia Minor and Caucasia

All articles

A peculiar new species of Scutisotoma Bagnall, 1949 (Collembola: Isotomidae) from Brazil

Maria Cleide de Mendonça & Tatiana Christina da Silveira

Title: A peculiar new species of Scutisotoma Bagnall, 1949 (Collembola: Isotomidae) from Brazil

Abstract
Samples collected from the National Park of Caparaó, in Minas Gerais state, revealed the presence of a new species Scutisotoma misha n. sp., which is distinguished from other congeners species by having a peculiar set of characters: simple maxillary palp, the absence of the labial guard chaetae e7, Ant. III without bms, 5,4/3,3,3,3,5 tergal sensilla (including 1,1/1,1,1 microsensilla) and one spatulate tenent chaeta on each tibiotarsus. In the present work the genus Scutisotoma Bagnall, 1949 is recorded for the first time in Brazil.

Keywords
Biodiversity | Neotropic | springtail | taxonomy

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DOI 10.25674/so-91-1-01

Maria Cleide de Mendonça
Departament of Entomology, National Museum, Federal University of Rio de Janeiro
Quinta da Boa Vista s/n, São Cristóvão, 20940-040, Rio de Janeiro, RJ, Brazil
cleidecollembola@gmail.com

Tatiana Christina da Silveira
Departament of Entomology, National Museum, Federal University of Rio de Janeiro
Quinta da Boa Vista s/n, São Cristóvão, 20940-040, Rio de Janeiro, RJ, Brazil

A taxonomic revision of the members of the Camponotus lateralis (Hymenoptera: Formicidae) from Europe, Asia Minor and Caucasia

Bernhard Seifert

Title: A taxonomic revision of the members of the Camponotus lateralis (Hymenoptera: Formicidae) from Europe, Asia Minor and Caucasia

Abstract
A taxonomic revision of the Camponotus lateralis group based on methods of Numeric Morphology-Based Alpha-Taxonomy (NUMOBAT) is presented considering the Palaearctic region west of 46°E. One size, nine shape and three setae characters were recorded in a total of 260 samples with 587 worker individuals. Species hypotheses were formed by three exploratory data analyses: the hierarchical methods NC-Ward and NC-part.hclust and the iterative vector-quantization method NC-part.kmeans. Samples with classifications disagreeing among the methods were finally allocated to a particular cluster by wild-card runs in a controlling linear discriminant analysis.

Results: The taxonomy of the C. lateralis group is complicated by the superimposition of three types of intraspecific polymorphism: (a) minor vs. major worker size dimorphism, (b) polymorphism of pigmentation pattern and (c), in at least one species, extreme dimorphism of shape and setae characters independent from size. A two-step cluster analysis and principal component analysis considering head and scape length indices and absolute size resulted in fully coincident separations of minors and majors with a general rule applicable for a collective of four long-headed and another rule applicable for a collective of four short-headed species. The identity of 42 taxa was evaluated on the basis of original descriptions and type specimens to exclude a junior synonymy of the taxon introduced here. A key is provided for nine valid species occurring in the area of Europe, Asia Minor and Caucasus: Camponotus lateralis (Olivier 1792), C. piceus (Leach 1825), C. atricolor (Nylander 1849), C. dalmaticus (Nylander 1849), C. candiotes Emery 1894, C. rebeccae Forel 1913, C. anatolicus Karaman & Aktac 2013, C. honaziensis Karaman & Aktac 2013 and C. heidrunvogtae sp. nov. The latter is restricted to a 120 000 km² area of the Balkans. Camponotus ebneri Finzi 1930 (stat. nov.) from Lebanon was raised to species level and is considered as sister species of C. dalmaticus. Seven taxa from North Africa, the Canaries and Middle East, showing a lot of similarities with species of the C. lateralis group, were excluded to represent synonyms of one of the ten aforementioned valid species. Further, seven Camponotus taxa from Europe, Asia Minor and the Middle East were clearly excluded from the C. lateralis group. Camponotus melanogastes (Latreille 1802), Camponotus axillaris (Spinola 1808), C. merula (Losana 1834) (syn. nov.), C. armouri Wheeler 1926, C. lateralis balearis Santschi 1929 (syn. nov.), C. lateralis purius Santschi 1929 (syn. nov.) and C. kosswigi Donisthorpe 1950 are synonymized under C. lateralis. Camponotus foveolata (Mayr 1853), C. ebeninus Emery 1869 (syn. nov.), C. piceus st. spissinodis var. dusmeti Santschi 1932 and C. figaro Collingwood & Yarrow 1969 (syn. nov.) were synonymized under C. piceus, C. lateralis var. cypridis Santschi 1939 (syn. nov.) under C. rebeccae and C. lateralis var. rectus Forel 1892 under C. atricolor. Due to insufficient original descriptions and missing types, there is no chance to conclude on either the specific, generic or tribal identity of six taxa supposed by previous authors of belonging to the C. lateralis group. These taxa – Formica bicolor Latreille 1798, Formica pallidinervis Brullé 1833, Camponotus hemipsila (Förster 1850), Camponotus sicheli Mayr 1866, Camponotus kiesenwetteri angustatus Forel 1889, and Camponotus lateralis var. rhodia Santschi 1934 – were listed under Incertae Sedis.

Keywords
numeric morphology-based alpha-taxonomy | nest centroid clustering | cryptic species | size dimorphism | color polymorphism

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DOI 10.25674/so-91-1-02

Bernhard Seifert
Senckenberg Museum of Natural History Görlitz, 
Am Museum 1, 02826 Görlitz, Germany
bernhard.seifert@senckenberg.de