Stochastic and deterministic processes differently affect the community structure of edaphic mites (Acari: Mesostigmata) in the southern Brazilian Atlantic Forest

2020 ◽  
Vol 25 (3) ◽  
pp. 577-592
Author(s):  
Matheus S. Rocha ◽  
Gabriela Reis-avila ◽  
Mateus M. Pires ◽  
Tairis Da-costa ◽  
Noeli J. Ferla ◽  
...  
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Stochastic Processes ◽  
Atlantic Forest ◽  
Plant Litter ◽  
Brazilian Atlantic Forest ◽  
Litter Depth ◽  
Spatial Parameters ◽  
Deterministic Processes ◽  
Mite Communities

Most mesostigmatid mites (Arachnida: Parasitiformes) are soil-dwelling predators, feeding predominantly on detritivorous and fungivorous invertebrates. Little is known about the role of environmental and spatial parameters in driving the structure of their local communities. The aim of this study is to assess the relative importance of environmental/spatial parameters in different scales and microhabitats on the community structure of edaphic mesostigmatid mites in the southern Brazilian Atlantic Forest. Soil and litter samples were collected in 20 sites (six subsamples per microhabitat per site; N = 240 samples) distant from each other over ranges varying from 100 m to seven km. Geographic distances between sampling sites and spatial eigenfunctions were used as proxies of stochastic processes to assess the influence of spatial parameters on mite community structure. Environmental parameters included soil grain size, moisture and organic matter, vegetation structure, litter depth and percentage of leaves, branches, and thin roots in plant litter. We collected 1135 Mesostigmata individuals from 77 species/morphospecies. Mite composition strongly differed between soil and litter microhabitats. Mite communities geographically closer were more similar to each other in terms of Mesostigmata composition than expected if there is no spatial structure. Litter depth, soil organic matter and soil moisture significantly contributed to edaphic mite community structure. Deterministic processes predominated in explaining the composition of the litter fauna, while the composition of the soil fauna was more sensitive to stochastic processes. Our results provide evidence that the composition of Mesostigmata communities not only differ between microhabitats, but they are differently structured by environmental and spatial parameters depending on the scale. This provides new insight into the processes affecting of mite diversity within soil ecosystem at fine and broad scales, and highlights the importance of the spatial proximity and microhabitat in driving the composition of mite communities.

Local, landscape and continental scale factors controlling earthworm community structure

2020 ◽  
Author(s):  
Ashley Cameron ◽  
Robert Bradley ◽  
Petra Benetkova ◽  
Agnieszka Józefowska ◽  
Gabriel Boilard ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Community Structure ◽  
Central Europe ◽  
Plant Litter ◽  
Agricultural Fields ◽  
Eastern Canada ◽  
Earthworm Species ◽  
Continental Scale ◽  
Scale Factors

<p>Past studies have praised earthworms for improving soil structure and fertility, but criticized earthworms for increasing the leaching of nutrients and soil greenhouse gas emissions. Therefore, in order to maximize the environmental benefits and reduce the environmental costs of earthworms, it is important to determine the factors controlling the structure of earthworm communities at local, landscape and continental scales. We first hypothesized that forested riparian buffer strips (FRBS) within agricultural landscapes would be a refuge for earthworms, due to higher soil moisture and organic matter compared to adjacent agricultural fields (“treatment” = FRBS vs. Field).  Within sites, we hypothesized that earthworms would be most abundant where the chemical quality of above- and belowground plant litter is high, or where soil disturbance is low. At the continental scale, we hypothesized that total summer precipitation interacts with regional and local scale factors in controlling earthworm community structure.  A field survey was conducted to quantify earthworm species abundances in FRBS and adjacent agricultural fields across Eastern Canada and Central Europe (two “bioregions” differing in rainfall). At each of 77 sites, we collected and identified earthworms from three plots within FRBS and adjacent agricultural fields, and noted the tree species, understory vegetation, drainage class, agricultural crop as well as five soil physicochemical variables (texture, pH, total C, total N and % organic matter). In each bioregion and treatment, we found proportionately more endogeic than anecic or epigeic earthworm species. In Eastern Canada there were proportionately fewer anecic and more epigeic individuals in FRBS than in fields, whereas in Central Europe there were fewer endogeic and more anecic earthworms in FRBS than in fields. We also found significant interactions between bioregion and treatment on total earthworm abundance and biomass, and on soil moisture. More specifically, in Eastern Canada we found higher earthworm abundance and biomass, soil moisture and organic matter in FRBS. Conversely, in Central Europe we found higher earthworm abundance and biomass in fields, no treatment effects on soil moisture, and higher soil organic matter in FRBS. The different earthworm distribution patterns in each bioregion were not related to the types of agricultural crops, but rather to differences in precipitation and soil moisture across bioregions. Within FRBS in Eastern Canada, earthworm abundance in deciduous and mixedwood stands were higher than in coniferous stands; in Central Europe, earthworm abundance was higher in deciduous stands only. Within FRBS in Eastern Canada, the abundance of the prominent endogeic species <em>Apporectodia rosea</em> was correlated with herbaceous plants, notably ferns and graminoids. Conditional regression tree analysis revealed positive relationships between earthworms and soil clay content, pH, moisture and organic matter. Our results suggest that local and landscape patterns in earthworm diversity can be predicted by soil and vegetation attributes, but the relative importance of these factors change across continual scales due to climate.  Comparing the distributions of earthworms across different scales provides insights into the potential of different species to spread into new habitats with climate change.</p>

Inside‐container effects drive mosquito community structure in Brazilian Atlantic forest

2019 ◽  
Vol 167 (6) ◽  
pp. 566-576
Author(s):  
Daniel Albeny‐Simões ◽  
Pedro Giovâni Silva ◽  
Jennifer Ann Breaux ◽  
Malva Isabel Medina Hernández
Keyword(s):  
Community Structure ◽  
Atlantic Forest ◽  
Brazilian Atlantic Forest

scholarly journals Aboveground and belowground arthropods experience different relative influences of stochastic versus deterministic community assembly processes following disturbance

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2545 ◽  
Author(s):  
Scott Ferrenberg ◽  
Alexander S. Martinez ◽  
Akasha M. Faist
Keyword(s):  
Community Structure ◽  
Stochastic Processes ◽  
Community Assembly ◽  
Tree Mortality ◽  
Mineral Soil ◽  
Relative Influence ◽  
Subalpine Forest ◽  
Arthropod Community ◽  
Arthropod Communities ◽  
Deterministic Processes

BackgroundUnderstanding patterns of biodiversity is a longstanding challenge in ecology. Similar to other biotic groups, arthropod community structure can be shaped by deterministic and stochastic processes, with limited understanding of what moderates the relative influence of these processes. Disturbances have been noted to alter the relative influence of deterministic and stochastic processes on community assembly in various study systems, implicating ecological disturbances as a potential moderator of these forces.MethodsUsing a disturbance gradient along a 5-year chronosequence of insect-induced tree mortality in a subalpine forest of the southern Rocky Mountains, Colorado, USA, we examined changes in community structure and relative influences of deterministic and stochastic processes in the assembly of aboveground (surface and litter-active species) and belowground (species active in organic and mineral soil layers) arthropod communities. Arthropods were sampled for all years of the chronosequence via pitfall traps (aboveground community) and modified Winkler funnels (belowground community) and sorted to morphospecies. Community structure of both communities were assessed via comparisons of morphospecies abundance, diversity, and composition. Assembly processes were inferred from a mixture of linear models and matrix correlations testing for community associations with environmental properties, and from null-deviation models comparing observed vs. expected levels of species turnover (Beta diversity) among samples.ResultsTree mortality altered community structure in both aboveground and belowground arthropod communities, but null models suggested that aboveground communities experienced greater relative influences of deterministic processes, while the relative influence of stochastic processes increased for belowground communities. Additionally, Mantel tests and linear regression models revealed significant associations between the aboveground arthropod communities and vegetation and soil properties, but no significant association among belowground arthropod communities and environmental factors.DiscussionOur results suggest context-dependent influences of stochastic and deterministic community assembly processes across different fractions of a spatially co-occurring ground-dwelling arthropod community following disturbance. This variation in assembly may be linked to contrasting ecological strategies and dispersal rates within above- and below-ground communities. Our findings add to a growing body of evidence indicating concurrent influences of stochastic and deterministic processes in community assembly, and highlight the need to consider potential variation across different fractions of biotic communities when testing community ecology theory and considering conservation strategies.

Natural Regeneration in Plantations of Native Trees in Lowland Brazilian Atlantic Forest: Community Structure, Diversity, and Dispersal Syndromes

2011 ◽  
Vol 19 (3) ◽  
pp. 379-389 ◽  
Author(s):  
Jerônimo Boelsums Barreto Sansevero ◽  
Pablo Viany Prieto ◽  
Luiz Fernando Duarte de Moraes ◽  
Pablo JoséFrancisco Pena Rodrigues
Keyword(s):  
Community Structure ◽  
Atlantic Forest ◽  
Natural Regeneration ◽  
Forest Community ◽  
Brazilian Atlantic Forest ◽  
Dispersal Syndromes ◽  
Native Trees ◽  
Structure Diversity

scholarly journals Differences in top-soil features between beech-mixture and Norway spruce forests of the Šumava Mts.

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 540-555 ◽  
Author(s):  
K. Matějka ◽  
J. Starý
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Species Diversity ◽  
Carbon Content ◽  
Norway Spruce ◽  
Forest Ecosystems ◽  
Oribatid Mite ◽  
Organic Matter Quality ◽  
Top Soil ◽  
Mite Communities

Top-soil samples were taken from four mountain forest ecosystems in the Bohemian Forest to compare the processes in European beech-mixture <I>(Fs</I>) and Norway spruce (<I>Pa</I>) dominating ecosystems. Selected plots can be grouped into two types of forest ecosystems which are conditioned by position on the natural altitudinal gradient. Several chemical features (content of organic matter, properties of humic and fulvic acids, releasable P, Ca, Mg, Fe and Al content) were compared with the species structure of oribatid mite communities in the same samples. Strict differences between both ecosystem types were discovered. Statistically significant differences were detected in Mg content (0.42 mg/g in <I>Fs</I> ecosystems compared to 0.30 mg/g in <I>Pa</I> ecosystems) and in organic matter quality (the ratio of carbon content in humic acids to carbon content in total humus acids was 0.53 in <I>Fs</I> ecosystems and 0.66 in <I>Pa</I> ecosystems) and quantity (e.g. content of humic acid carbon was 59 and 86 mg/g in <I>Fs</I> and <I>Pa</I> ecosystems, respectively). Different dynamics of organic matter decomposition and nutrient movement lead to some opposite correlations among the soil chemical features: correlation between total ash and soluble ash (<I>r</I> = +0.96 and –0.86 in the <I>Fs</I> and Pa ecosystems, respectively) and total ash – P content correlation (<I>r</I> = +0.76 and –0.92 in the <I>Fs</I> and <I>Pa</I> ecosystems, respectively) can be mentioned as examples. The oribatid mite communities are markedly distinct in both ecosystem types, although parameters of species diversity and abundance are similar. Different correlations were revealed between the parameters of mite community structure (e.g. species diversity and total mite abundance) and top-soil chemical features. The correlation structure is different in both ecosystem types. It indicates differences in leading variables determining the oribatid community structure in the beech mixture ecosystem or in the Norway spruce one.

scholarly journals Organic matter dynamics in a savanna transition riparian zone: input of plant reproductive parts increases leaf breakdown process

2017 ◽  
Author(s):  
Renan S. Rezende ◽  
Patrícia R.S. Correia ◽  
José F. Gonçalves Jr ◽  
Anderson M. Santos
Keyword(s):  
Organic Matter ◽  
Leaf Litter ◽  
Atlantic Forest ◽  
Riparian Zone ◽  
High Energy ◽  
Plant Litter ◽  
Freshwater Ecosystems ◽  
Litter Breakdown ◽  
Leaf Litter Breakdown ◽  
Leaf Mass

<p>The dynamics of coarse particulate organic matter (CPOM) drives the functioning of most low order freshwater ecosystems. We evaluated plant litter input, litterfall, leaf litter breakdown rates, and the aquatic invertebrate community over the course of one year in a stream situation in a transition zone between savannah and Atlantic forest. Total organic matter input (litter fall) was 335 g m<sup>-2</sup> yr<sup>-1</sup>, which was mainly composed of leaves (50%). Higher values are found in the transition from dry to rainy season (September and October), probably in response to water stress. The remaining leaf mass (65% on average) was lowest in May (49%) and highest in August (79%). CPOM productivity in this transition riparian zone is higher than in other savannah systems, but lower than in Atlantic forest. The higher leaf litter breakdown in May was likely accompanied by environmental enrichment due to increase in fruits and flowers (high energy resources). The coefficient of decomposition was classified as fast (k= -0.016) and showed a positive relationship with water flow (increase in physical abrasion). Collected invertebrates were classified as 6% shredders and 12% scrapers. The remaining leaf mass showed a negative relationship with scraper abundance, highlighting the importance of these trophic groups in tropical streams. We can conclude that climate factors (e.g., rainfall) directly affect the input and quality of CPOM and, consequently, leaf decomposition in savanna/Atlantic forest transition zones. </p>

The centipede genus Otostigmus Porat in Brazil: Description of three new species from the Atlantic Forest; a summary and an identification key to the Brazilian species of this genus (Chilopoda, Scolopendromorpha, Scolopendridae, Otostigminae)

Zootaxa ◽  
2012 ◽  
Vol 3280 (1) ◽  
pp. 1 ◽  
Author(s):  
AMAZONAS CHAGAS-JÚNIOR
Keyword(s):  
New Species ◽  
Atlantic Forest ◽  
The State ◽  
Junior Synonym ◽  
Identification Key ◽  
Nominal Species ◽  
Brazilian Atlantic Forest ◽  
Three New Species ◽  
First Time ◽  
New Distribution

Three new species of Otostigmus Porat, 1876 from Brazilian Atlantic Forest are described. Otostigmus beckeri sp. n. andO. lanceolatus sp. n. are described from the state of Bahia and O. giupponii sp. n. from the state of Espírito Santo. InBrazil, the otostigmine scolopendrid genus Otostigmus comprises 22 species. A summary of Brazilian Otostigmus speciesis presented with new distribution records, taxonomic remarks when appropriate and an identification key. Otostigmus sul-catus Meinert, 1886 is recorded for the first time from Brazil; the Andean Otostigmus silvestrii Kraepelin 1903, previouslyrecorded from Brazil, is here considered not to be present in this country. Eight nominal species are regarded here as newsynonyms. Five of them—Otostigmus pradoi Bücherl, 1939, O. longistigma Bücherl, 1939, O. longipes Bücherl, 1939,O. langei Bücherl, 1946 and O. dentifusus Bücherl, 1946—are based on females of O. tibialis Brölemann, 1902. O. latipesBücherl, 1954 is conspecific with and is considered a junior synonym of O. sulcatus Meinert, 1886; O. limbatus diminutusBücherl, 1946 is a junior synonym of O. limbatus Meinert, 1886 and O. fossulatus Attems, 1928 is a junior synonym of O. goeldii Brölemann, 1898. A lectotype is designated for O. goeldii.

scholarly journals Impacts of long-term plant residue management on soil organic matter quality, Pseudomonas community structure and disease suppressiveness

2019 ◽  
Vol 135 ◽  
pp. 396-406 ◽  
Author(s):  
Bryony E.A. Dignam ◽  
Maureen O'Callaghan ◽  
Leo M. Condron ◽  
Jos M. Raaijmakers ◽  
George A. Kowalchuk ◽  
...  
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Soil Organic Matter ◽  
Residue Management ◽  
Plant Residue ◽  
Organic Matter Quality ◽  
Soil Organic Matter Quality
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