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

2018 ◽  
Author(s):  
Annika Eva Schulz ◽  
Nico Eisenhauer ◽  
Simone Cesarz
Keyword(s):  
Community Composition ◽  
Extraction Efficiency ◽  
Soil Aggregates ◽  
Total Density ◽  
Soil Nematode ◽  
Soil Biodiversity ◽  
Extraction Protocol ◽  
Filter Type ◽  
Paper Towels ◽  
Baermann Funnel

AbstractNematodes 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 locales. 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, amount of soil, sieving, 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 weight (25 g instead of 50 g or 100 g) in combination with soil 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 amount of soil increased the proportion of larger-sized nematodes being able to overcome long distances. 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. 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.

scholarly journals Soil nematode community composition and stability under different nitrogen additions in a semiarid grassland

2020 ◽  
Vol 22 ◽  
pp. e00965 ◽  
Author(s):  
Siwei Liang ◽  
Xinchang Kou ◽  
Yingbin Li ◽  
Xiaotao Lü ◽  
Jingkuan Wang ◽  
...  
Keyword(s):  
Community Composition ◽  
Nematode Community ◽  
Soil Nematode ◽  
Semiarid Grassland ◽  
Soil Nematode Community ◽  
Nitrogen Additions

scholarly journals Nitrogen Addition Regulates Soil Nematode Community Composition through Ammonium Suppression

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e43384 ◽  
Author(s):  
Cunzheng Wei ◽  
Huifen Zheng ◽  
Qi Li ◽  
Xiaotao Lü ◽  
Qiang Yu ◽  
...  
Keyword(s):  
Community Composition ◽  
Nitrogen Addition ◽  
Nematode Community ◽  
Soil Nematode ◽  
Soil Nematode Community

scholarly journals The legacy of deer overabundance: long-term delays in herbaceous understory recovery

2016 ◽  
Vol 46 (3) ◽  
pp. 362-369 ◽  
Author(s):  
Thomas H. Pendergast ◽  
Shane M. Hanlon ◽  
Zachary M. Long ◽  
Alejandro A. Royo ◽  
Walter P. Carson
Keyword(s):  
Community Composition ◽  
Community Response ◽  
Forest Understory ◽  
Total Density ◽  
Eastern United States ◽  
Legacy Effect ◽  
Browse Species ◽  
Understory Communities ◽  
Open Question ◽  
And Control

Decades of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) overpopulation have dramatically homogenized forests across much of the eastern United States, creating depauperate forest understory communities. The rate at which these communities recover once deer browsing has been reduced remains an open question. We evaluate overbrowsing legacy effects by examining how forest herbaceous layers respond in terms of biodiversity, density, and community composition over 11 years using exclosures and control plots within a mature beech–maple forest. Although little recovery occurred in the first 5 years, total density and preferred browse density rebounded substantially during the final years of the study. Although community composition began to diverge between exclosure and control plots after 5 years, diversity failed to recover even after 11 years of excluding browsers. Our findings show that vulnerable species can increase after excluding browsers but only if those species were initially present. Biodiversity recovery may be extremely slow because preferred browse species have been nearly extirpated from many forests and thus are unable to recruit into refugia. We empirically demonstrate the extent of the ghost of herbivory past or legacy effect of browsing, i.e., the substantial time delay between herbivore abatement and community response after decades of high deer densities.

scholarly journals Rhizosphere bacterial community composition depends on plant diversity legacy in soil and plant species identity

2018 ◽  
Author(s):  
Marc W. Schmid ◽  
Terhi Hahl ◽  
Sofia J. van Moorsel ◽  
Cameron Wagg ◽  
Gerlinde B. De Deyn ◽  
...  
Keyword(s):  
Species Diversity ◽  
Microbial Communities ◽  
Community Composition ◽  
Plant Species ◽  
Plant Diversity ◽  
Bacterial Communities ◽  
Biodiversity Loss ◽  
Plant Species Diversity ◽  
Species Identity ◽  
Soil Biodiversity

AbstractSoil microbes are known to be involved in a number of essential ecosystem processes such as nutrient cycling, plant productivity and the maintenance of plant species diversity. However, how plant species diversity and identity affect soil microbial diversity and community composition is largely unknown. We tested whether, over the course of 11 years, distinct soil bacterial communities developed under plant monocultures and mixtures, and if over this timeframe plants with a monoculture or mixture history changed in the microbial communities they associated with. For eight species, we grew offspring of plants that had been grown for 11 years in the same monocultures or mixtures (monoculture- or mixture-type plants) in pots inoculated with microbes extracted from the monoculture and mixture soils. After five months of growth in the glasshouse, we collected rhizosphere soil from each plant and used 16S-rRNA gene sequencing to determine the community composition and diversity of the bacterial communities. Microbial community structure in the plant rhizosphere was primarily determined by soil legacy (monoculture vs. mixture soil) and by plant species identity, but not by plant legacy (monoculture- vs. mixture-type plants). In seven out of the eight plant species bacterial abundance was larger when inoculated with microbes from mixture soil. We conclude that plant diversity can strongly affect belowground community composition and diversity, feeding back to the assemblage of rhizosphere microbial communities in newly establishing plants. Thereby our work demonstrates that concerns for plant biodiversity loss are also concerns for soil biodiversity loss.

Effects of organic and conventional pesticides on plant biomass, nematode diversity and the structure of the soil food web

Nematology ◽  
2015 ◽  
Vol 17 (1) ◽  
pp. 11-26 ◽  
Author(s):  
Marina Carrascosa ◽  
Sara Sánchez-Moreno ◽  
José Luis Alonso-Prados
Keyword(s):  
Management Practices ◽  
Plant Biomass ◽  
Chemical Properties ◽  
Nematophagous Fungi ◽  
Parasitic Nematodes ◽  
Soil Nematode ◽  
Soil Biodiversity ◽  
Nematode Diversity ◽  
Pine Forest Soil ◽  
Soil Fumigants

Due to the uncertain future of the soil fumigants most commonly used in the EU, there is a need to develop new integrated pest management programmes to control crop diseases. Different nematode management practices, such as solarisation and the use of ecological nematicides, including nematophagous fungi, are used to control populations of plant-parasitic nematodes, one of the most common pests affecting crops. The objective of this study was to determine the effects of organic (neem seed paste and a mixture of nematophagous fungi) and conventional (oxamyl and fenamiphos) nematicides on soil physical chemical properties, soil biodiversity and plant biomass. Such effects were investigated in two types of habitats: low diversity soils from an agricultural farm and high diversity soils from a natural vegetation area. The greater effect was observed with the neem treatment, which induced a large boost of dauer juveniles in the nutrient-depleted soil, while the same treatment induced an increase of populations of less opportunistic, generalist bacterivore nematodes in the pine forest soil, rich in organic matter. We have studied the effects of different biological and chemical nematicides on the whole soil nematode community through ecological indices and their relationship with plant biomass, but further research is needed to improve understanding of the effect of these products on nematode assemblages.

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