Soil Collembola communities along a steep microclimatic gradient in the collapse doline of the Silická ľadnica Cave, Slovak Karst (Slovakia)

AbstractIn spring 2005 we investigated the collembolan communities in the 50-m-deep collapse doline of the perennial ice cave Silická ľadnica in the Slovak Karst (Slovakia). Samples were taken at seven sites along a 117.5-m-long transect on the slope from the ice-bearing cave mouth at the bottom of the doline up to the terrain surface at 500 m above sea level (a.s.l.). The temperature above the soil surface (+0.6 to +13.6°C) positively correlated with altitude. Species numbers (ranging from 20–32) and diversity indices were highest at sites in the middle of the slope with rendzina and well developed organic profiles. A Kruskal-Wallis ANOVA revealed significant differences in abundance between the sites. Mean abundance near the permafrost zone at the bottom of the doline was significantly higher than at the sites further upslope. The abundances of some eurytopic and forest species were significantly correlated with soil temperature. Cluster analysis and the IndVal method indicated differences in the structure of Collembolan communities along the transect. The community at the coldest site had the lowest species richness and the highest mean abundance of individuals. A total of ten montane species were recorded, with a lower number near the permafrost zone compared to the micro-climatically more favourable middle section of the gradient.

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Intertillage during Natural Farming Rice Paddy Production Negatively Impacted the Microbial Abundances in Soils but Not Diversities

Applied and Environmental Soil Science ◽

10.1155/2021/6676456 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Jin-Feng Lin ◽

Eva-Maria Minarsch ◽

Munehide Ishiguro ◽

Yoshitaka Uchida

Keyword(s):

Bacterial Community ◽

Soil Microbial Communities ◽

Soil Surface ◽

Rice Paddy ◽

Diversity Indices ◽

Vegetative Stage ◽

Rice Paddies ◽

Community Structures ◽

Natural Farming ◽

Soil Bacterial

In natural farming rice paddies, intertillage (tillage between rows, during rice growth period) is often performed mainly to remove weeds without the use of chemicals. Also, the intertillage disturbs soil surfaces, potentially impacting the characteristics of soil microbial communities, such as their diversity and abundance. Natural farming systems aim to maintain biodiversity, but it remains unclear whether the intertillage impacts soil microbes in rice paddies. Thus, this study aimed to understand to what extent “five times intertillage” treatment (5T) influences soil bacterial abundance and community structures compared with no tillage (NT), under a natural farming rice paddy system. Soils were sampled at rice proximity, soil surface, and 10 cm depth in a natural farming rice paddy, during the early to late vegetative phase (June to July), in Hokkaido, Japan. The 16S rRNA community structures and abundance were analyzed by next generation sequencing (NGS) and quantitative PCR, respectively. We observed that NT had significantly higher bacterial abundances at the soil surface than 5T. However, there were no clear differences between 5T and NT, regarding the bacterial community structures, including their diversity indices. Instead, the sampling timings markedly impacted the bacterial community structures for the rice proximity and soil surface, showing increasing diversity indices at the late vegetative stage, compared to the early vegetative stage, suggesting the interaction between the crop growth and bacterial communities. In this study, we did not observe the significant difference between the rice yield from NT (2.3 ± 0.7 t·ha−1) and 5T plots (2.7 ± 0.9 t·ha−1); however, the 5T might have negatively impacted soil bacterial abundances but not the community structure of the bacteria.

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Windows of opportunity in desert ecosystems: their implications to fungal community development

Canadian Journal of Botany ◽

10.1139/b95-404 ◽

1995 ◽

Vol 73 (S1) ◽

pp. 1407-1414 ◽

Cited By ~ 39

Author(s):

John C. Zak ◽

Robert Sinsabaugh ◽

William P. MacKay

Keyword(s):

Community Development ◽

Functional Diversity ◽

Fungal Community ◽

Large Scale ◽

Soil Surface ◽

Root Surface ◽

Fungal Species ◽

Desert Ecosystems ◽

Species Numbers ◽

Fungal Activity

At the ecosystem level, all fungal activity in arid and semiarid systems is water regulated. However, as the observation scale is changed to allow for finer resolution of moisture effects, one finds that fungal community development in deserts may be influenced by either the temporal patterning of moisture pulses, or biotic factors that extend the benefits of moisture windows. When selected biocides were applied to the root region of a desert bunchgrass, Erioneuron pulchellum, to reduce microarthropod and nematode densities, fungal species numbers associated with the root surface were not altered. The temporal pattern in species numbers apparently reflect large scale seasonal responses of the fungi, microfauna, and plants to yearly differences in the occurrences of moisture windows. For wood on the soil surface, moisture windows of short duration coupled with high temperatures restrict fungal species composition in this habitat resulting in a lack of turnover in the dominant fungal species on surface wood. However, when wood was placed in the more amenable environment of a woodrat midden, patterns of fungal community development differed significantly from that observed for wood on the soil surface. These studies indicate that our understanding of the roles of fungi in the functioning of desert ecosystems is biased because the scale at which we usually make observations is too large to account for abiotic and biotic influences on fungal activity and community development. Moreover, we have to realize that the occurrence of favorable habitats for fungi in arid systems varies considerably in space and time. One consequence of the high spatial and temporal heterogeneity in favorable habitats is that functional diversity among fungi may be greater than would be predicted based solely on abiotic considerations. Key words: deserts, environmental heterogeneity, functional diversity, scale, wood.

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Impact of RR Soybeans and Glyphosate on the Community of Soil Surface Arthropods

Planta Daninha ◽

10.1590/s0100-83582018360100071 ◽

2018 ◽

Vol 36 (0) ◽

Author(s):

J.L. PEREIRA ◽

M.C. LOPES ◽

J.B. PARISH ◽

A.A. SILVA ◽

M.C. PICANÇO

Keyword(s):

Soil Surface ◽

Lower Number ◽

The Other ◽

Transgenic Soybean ◽

Large Area ◽

Resistant Gene ◽

Minas Gerais State ◽

Tropical Areas ◽

Soybean Plants ◽

The Impact

ABSTRACT: The cultivation of transgenic soybean plants using the glyphosate resistant gene (RR soybeans), takes up about 47% of the world’s cropping area. Despite the large area planted with soybeans resistant to glyphosate, there are very few studies of the environmental impact of this technology, especially in tropical areas. Thus, this study aimed to evaluate the impact of the cultive of RR soybeans and the use of glyphosate on the community of soil surface arthropods. The experiment was conducted in Coimbra, Minas Gerais state for two agricultural years. The experimental design was conducted in randomized blocks with five replications. The treatments were: non-transgenic soybean with mechanical weeding; RR soybean with mechanical weeding; RR soybean with one application of glyphosate and RR soybean with three applications of glyphosate. The populations of the soil surface arthropods were sampled over two years of cultivation (2007/2008 and 2008/2009). The cultive of RR soybean did not affect the richness and abundance of arthropods. A lower number of predators and detritivorous arthropods were observed in the treatments with one or three applications of glyphosate. Lower densities of arthropods were observed on the cultive of transgenic soybeans with three applications of glyphosate compared to the other treatments, especially the predators Achaearaneasp. (Araneae: Theridiidae), Oxypodinisp. (Coleoptera: Staphylinidae), Solenopsisspp. (Hymenoptera: Formicidae), the detritivorous Entomobryidae (Collembola), Hypogastrurasp. (Collembola: Hypogastruridae) and Xyleborussp. (Coleoptera: Scolytidae). The results indicate that the insertion of the glyphosate resistant gene does not affect the richness and abundance of the arthropods, however the use of glyphosate reduce the densities of predators and detritivorous on the soil surface.

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Nutrient fluxes in throughfall and stemflow in forest Cerrado species

10.5194/egusphere-egu2020-2465 ◽

2020 ◽

Author(s):

Kelly Cristina Tonello ◽

Alexandra Guidelli Rosa ◽

Manuel Enrique Gamero Guandique ◽

Luara Castilho Pereira ◽

Gregorio Nolazco Matus ◽

...

Keyword(s):

Forest Canopy ◽

Chemical Elements ◽

Soil Nutrient ◽

Soil Surface ◽

Solute Concentration ◽

Natural Environments ◽

Forest Species ◽

Nutrient Input ◽

Liquid Chromatograph ◽

Physicochemical Features

Although recognized as a hotspot, being one of the most diverse biomes in Brazil and responsible for recharging the main aquifers in South America, the Cerrado has been suffering from intense deforestation. Since rainfall, after reaching the forest canopy, has its physicochemical features altered by the metabolites leaching from the leaves tissues, branches, and stem, this study was developed in order to obtain information about the hydrological processes in the biome and the potential of nutrient input by their forest species. There is a lack of studies as proposed in natural environments such as Cerrado. Based on this, we have evaluated the relative importance of stemflow and throughfall solute concentrations to the soil surface in a Cerrado forest in Brazil and also the potential of stemflow by 8 Cerrado species to soil nutrient input. The following chemical aspects from rainfall, throughfall and stemflow were determined: Na2+, K+, hardness (Ca2+ and Mg2+), Cl-, , PO3- and &#160;on a liquid chromatograph Metrohm ECO IC during august to december 2018. The comparison between mean concentration, showed that most of the elements and compounds were more concentrated in throughfall and stemflow, except for Na2+ and Ca2+, which were more concentrated in rainfall (p <0.05). While the amount of stemflow channeled to the tree trunks comprised approximately 4% of rainfall, some nutrients in stemflow were enriched up to 10-fold in comparison to throughfall and rainfall. When we have discriminated the solute concentration by stemflow between 8 forest species from Cerrado, we have noted that each species has a specific contribution to the stemflow nutrient and for most of the species, the ion concentrations in the stemflow water is higher than those found in the rainfall and throughfall. Xylopia aromatica has shown the major difference between the solute concentrations when compared within other species. The total input of nutrients fluxes, as the amount of rainfall loading had been ranked as follows: K+ > Ca2+ > Mg2+ > NO3 > > > Cl- > Br-. The highest nutrient input by stemflow was for K+, which ranged from 7.91 (H. ochraceus) to 114.08 (X. aromatica) kg ha-1.These results highlight the importance of investigating the individual contribution of each species in the stemflow in Cerrado forest, suggesting a variety in nutrient input through the biogeochemical cycle and could be a strategy to accommodate the species for soil recovering. The knowledge of the biogeochemical dynamic helps to understand the processes that are responsible for the sustainability of forest ecosystems and the forest ecosystem plays an important role in water balance, not only in terms of water quantity (volume) but also in the distribution of the chemical elements.

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Use of simulated data as a tool for testing the performance of diversity indices in response to an organic enrichment event

ICES Journal of Marine Science ◽

10.1093/icesjms/fsn119 ◽

2008 ◽

Vol 65 (8) ◽

pp. 1456-1461 ◽

Cited By ~ 2

Author(s):

Jon Barry ◽

Hubert L. Rees

Keyword(s):

Simulated Data ◽

Diversity Indices ◽

Organic Enrichment ◽

Event History ◽

Ecological Framework ◽

Marine Science ◽

Species Numbers ◽

Stochastic Nature ◽

Simulation Process

Abstract Barry, J., and Rees, H. L. 2008. Use of simulated data as a tool for testing the performance of diversity indices in response to an organic enrichment event. – ICES Journal of Marine Science, 65: 1456–1461. We demonstrate how data on macrobenthic species numbers and abundance after an organic enrichment event can be simulated using the empirical Pearson–Rosenberg model in combination with further plausible ecological assumptions. The simulations were programmed in the statistical package R, using an ecological framework that included classification of species into opportunistic, tolerant, and sensitive types, together with probabilities for the occurrence of these types at any particular point in the event history. The simulations also included assumptions about the dominance of species types. The exercise was successful in that realistic, simulated datasets could be produced quickly and, because of the stochastic nature of parts of the simulation process, repeat simulations allowed variation of selected diversity indices calculated on the series to be assessed. The approach could provide a useful tool to evaluate both existing and new indicators.

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Floristic Survey of Meethirigala Forest Reserve in Gampaha District

Journal of Tropical Forestry and Environment ◽

10.31357/jtfe.v10i1.4689 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

J.D. Kalubowila ◽

B.M.P. Singhakumara ◽

R.A.M.P.M. Rajathewa

Keyword(s):

Plant Species ◽

Forest Type ◽

Diversity Indices ◽

Forest Species ◽

Forest Reserve ◽

Woody Perennials ◽

Reserve Forest ◽

Study Sites ◽

Topographic Positions ◽

Kelani River

Meethirigala forest reserve consists of approximately 384 ha. It is the largest forest reserve in Gampaha District managed by the Forest Department. It has different topographic positions such as ridges, midslopes and valley areas close to the Kelani River. The present study was conducted to enumerate plant species found in all three topographic positions of the reserve. Plots were demarcated purposively to sample woody perennials equal or greater than 5 cm dbh (diameter at breast height) in 18 plots (5×100 m, rectangular shape). Seedlings greater than 1 m tall were sampled in 18 plots (5×5 m). Shannon diversity indices were calculated to compare dominance of particular species in different topographic positions. A total of 360 individuals of woody perennials belonging to 73 species in ridge, 368 individuals of woody perennials belonging to 100 species in midslope and 272 individuals of woody perennials belonging to 69 species in valley were recorded. And 132, 123 and 100 individuals of seedlings were enumerated in ridge, midslope and valley respectively. In ridge 58 generas, 28 families, in midslope 83 generas, 35 families and, in valley 68 generas, 29 families were observed. 28 species were found in all three different altitudes of the reserve. Forest species in study sites gave a total of 138 plant species belonging to 113 tree species, 11 climber species, 14 shrub species, 109 generas and 46 families. Of this total 138 species, 34 (25%) species are endemic to Sri Lanka. Highest endemism was recorded in the ridge (41.6%). Stratification of the ridge showed a very similar pattern to a Dipterocarp forest type. Highest diversity was recorded in midslope (1.7290) and lowest recorded in ridge (1.5626) of the forest. 18 threatened species were observed (3-Endangered and 15-vulnerable species). As a conclusion, Meethirigala forest reserve can be considered as an important refuge for wet zone forest species.

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Modelling the mineralisation of plant residues on the soil surface

Agronomie ◽

10.1051/agro:2002042 ◽

2002 ◽

Vol 22 (7-8) ◽

pp. 711-722 ◽

Cited By ~ 9

Author(s):

Axel Berkenkamp ◽

Eckart Priesack ◽

Jean Charles Munch

Keyword(s):

Soil Surface ◽

Plant Residues

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Status and development prospects of standard means for reproducing units of volumetric activity of radon and thoron and radon flux density from the soil surface

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-1-69-73 ◽

2020 ◽

pp. 69-73

Author(s):

S.G. Birjukov ◽

O.I. Kovalenko ◽

A.A. Orlov

Keyword(s):

Flux Density ◽

Soil Surface ◽

National Standards ◽

Measuring Instruments ◽

Volumetric Activity ◽

Standard Means ◽

Radon Flux ◽

Technical Solutions ◽

Development Prospects ◽

Physical Principles

The approach to creating standard means for reproducing units of volumetric activity of radon and thoron and flux density of radon from the soil surface is described based on the physical principles of reproducing these units of quantities and using as technical means for reproducing bubblers with a radioactive solution of radium salt, reference capacities of known volume, emanation chambers for generation of a toron, a gamma spectrometer with a semiconductor detector from highly pure germanium and radon radiometers. Reproduction consists in the physical realization of units in accordance with their definition as applied to the formation of radon and thoron in the radioactive rows of radium and thorium. The proposed approach will allow to determine the structural, structural and other technical solutions of standard measuring instruments, as well as specific techniques and methods of working with them. The creation of standard tools and technologies for reproducing units of volumetric activity of radon and thoron and the density of radon flux from the soil surface will ensure the unity and reliability of measurements in the field of ionizing radiation, traceability of units and bringing the characteristics of national standards in line with world achievements.

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Thysanoptera diversity associated with Mexican lemon (Citrus aurantifolia Christm.)

RECUBRIMIENTO COMESTIBLE CON BASE DE PIÑON MEXICANO (Jatropha curcas) SOBRE LA CALIDAD DE CHAYOTE MINIMAMENTE PROCESADO ◽

10.32854/agrop.vi.1761 ◽

2020 ◽

Vol 13 (9) ◽

Author(s):

Francisco Javier Avendaño-Gutiérrez ◽

Salvador Aguirre Paleo ◽

Alejandro Morales Hernández ◽

Venecia Quesadas-Béjar

Keyword(s):

Biosphere Reserve ◽

Simple Random Sampling ◽

Diversity Indices ◽

Diaphorina Citri ◽

Program Calculation ◽

Homogeneous Relation ◽

Candidatus Liberibacter ◽

Scirtothrips Citri ◽

Species Richness And Abundance ◽

First Time

Objective: To calculate the monthly relative abundance of Thysanoptera species, according to the Margalef, Simpson and Shannon-Wiener diversity indices. Design / Methodology / Approach: The work was carried out in three geographic units with conventional management, during January-December, 2019 in the Reserva de la Biosfera Zicuirán-Infiernillo (Biosphere Reserve), Michoacán, Mexico. In each unit, 10 trees were selected through simple random sampling. Thrips counts were performed on ten shoots per tree every 15 d, for a total of 7200 shoots in the three geographic units. Thysanoptera individuals were placed in entomological jars. The variables were: number of thrips collected per shoot in sampled tree and geographic unit (orchard). To estimate the specific richness and structure of species, the program "calculation of diversity indices DIVERS" was used. Results: In the three geographical units studied, the recorded presence of Thysanoptera accounted for 12 to 17 species. For Nueva Italia 12 recorded species, two were permanent (16.66%), five abundant (41.66%), one scarce (8.3%) and four rare (33.33%). In Zicuirán, three species were permanent (17.64%), six abundant (35.29%), two scarce (11.76%) and six rare (35.29%). In Los Hoyos, four species were permanent (26.66%), four abundant (26.66%) and seven rare (46.66%). The abundance of species was represented by the genus Frankliniella and the species Scolothrips sexmaculatus and Scirtothrips citri. The highest species richness and abundance was found from January to May. In October and November, the value of the calculated indices was zero, which shows less richness and abundance of individuals. The best species uniformity was recorded during January and December, which meant a more stable and homogeneous relation. Study limitations/Implications. Pest resurgence, presence of Candidatus Liberibacter spp. and its vector Diaphorina citri. Findings / Conclusions: in Nueva Italia, 12 species were taxonomically determined; in Los Hoyos 15, and in Zicuirán 17 species, which are reported for the first time in the state of Michoacán, Mexico. At the geographic unit "Los Hoyos" diversity was higher, uniform and stable.

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Climate resilience through natural regeneration in degraded natural forests of south-eastern hilly region of Bangladesh

Bangladesh Journal of Botany ◽

10.3329/bjb.v48i3.47720 ◽

2019 ◽

Vol 48 (3) ◽

pp. 417-425

Author(s):

Md Khayrul Alam Bhuiyan ◽

Md Akhter Hossain ◽

Abdul Kadir Ibne Kamal ◽

Mohammed Kamal Hossain ◽

Mohammed Jashimuddin ◽

...

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

Diversity Indices ◽

Acacia Auriculiformis ◽

Quantitative Structure ◽

Natural Forests ◽

Climate Resilience ◽

Hilly Region ◽

Major Cluster ◽

Ecological Dominance

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.

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