Neoisoptera repetitively colonised Madagascar after the Middle Miocene climatic optimum

AbstractMadagascar is home to many endemic plant and animal species owing to its ancient isolation from other landmasses. This unique fauna includes several lineages of termites, a group of insects known for their key role in organic matter decomposition in many terrestrial ecosystems. How and when termites colonised Madagascar remains unknown. In this study, we used 601 mitochondrial genomes, 93 of which were generated from Madagascan samples, to infer the global historical biogeography of Neoisoptera, a lineage containing upwards of 80% of described termite species. Our results indicate that Neoisoptera colonised Madagascar between seven to ten times independently during the Miocene, between 8.4-16.6 Ma (95% HPD: 6.1-19.9 Ma). This timing matches that of the colonization of Australia by Neoisoptera. Furthermore, the taxonomic composition of the Neoisopteran fauna of Madagascar and Australia are strikingly similar, with Madagascar harbouring an additional two lineages absent from Australia. Therefore, akin to Australia, Neoisoptera colonised Madagascar during the global expansion of grasslands, possibly helped by the ecological opportunities arising from the spread of this new biome.

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Linking Genes to Traits in Fungi

Microbial Ecology ◽

10.1007/s00248-021-01687-x ◽

2021 ◽

Author(s):

A. L. Romero-Olivares ◽

E. W. Morrison ◽

A. Pringle ◽

S. D. Frey

Keyword(s):

Organic Matter ◽

Nitrogen Uptake ◽

Brown Rot ◽

Terrestrial Ecosystems ◽

Organic Matter Decomposition ◽

Gene Frequencies ◽

Ecological Processes ◽

Linked Gene ◽

Carbon Cycles ◽

Brown Rot Fungi

AbstractFungi are mediators of the nitrogen and carbon cycles in terrestrial ecosystems. Examining how nitrogen uptake and organic matter decomposition potential differs in fungi can provide insight into the underlying mechanisms driving fungal ecological processes and ecosystem functioning. In this study, we assessed the frequency of genes encoding for specific enzymes that facilitate nitrogen uptake and organic matter decomposition in 879 fungal genomes with fungal taxa grouped into trait-based categories. Our linked gene-trait data approach revealed that gene frequencies vary across and within trait-based groups and that trait-based categories differ in trait space. We present two examples of how this linked gene-trait approach can be used to address ecological questions. First, we show that this type of approach can help us better understand, and potentially predict, how fungi will respond to environmental stress. Specifically, we found that trait-based categories with high nitrogen uptake gene frequency increased in relative abundance when exposed to high soil nitrogen enrichment. Second, by comparing frequencies of nitrogen uptake and organic matter decomposition genes, we found that most ectomycorrhizal fungi in our dataset have similar gene frequencies to brown rot fungi. This demonstrates that gene-trait data approaches can shed light on potential evolutionary trajectories of life history traits in fungi. We present a framework for exploring nitrogen uptake and organic matter decomposition gene frequencies in fungal trait-based groups and provide two concise examples on how to use our framework to address ecological questions from a mechanistic perspective.

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Frequência, diversidade e composição da fauna de cupins (Blattodea: Isoptera) em diferentes sistemas de uso do solo no sudoeste do Amazonas, Brasil

EntomoBrasilis ◽

10.12741/ebrasilis.v11i2.729 ◽

2018 ◽

Vol 11 (2) ◽

pp. 78-84 ◽

Cited By ~ 2

Author(s):

Agno Nonato Serrão Acioli

Keyword(s):

Land Use ◽

Species Richness ◽

Oil Palm ◽

Elaeis Guineensis ◽

Taxonomic Composition ◽

Primary Forest ◽

Agricultural Crops ◽

Termite Species ◽

Land Use Systems ◽

Elaeis Guineensis Jacq

Resumo. Os cupins são importantes decompositores da matéria de origem vegetal. Este estudo teve como objetivo analisar e comparar a diversidade e composição das espécies de cupins em três diferentes sistemas de uso do solo na região do Alto Solimões, Amazonas, Brasil. Os cupins foram coletados na floresta primária, em cultivos de dendê (Elaeis guineensis Jacq.) e mandioca (Manihot sculenta Crantz). Em cada área selecionada as coletas foram realizadas dentro de um transecto retangular medindo 100 m x 2 m, subdivididos em 20 parcelas de 5 m x 2 m. Foram encontradas 24 espécies de cupins, pertencentes a 14 gêneros e duas famílias, nos três sistemas de uso do solo. As espécies mais frequentes foram Nasutitermes cf. dendrophilus (Desneux) (28,43%), seguida de Heterotermes tenuis (Hagen) (14,37%) e Anoplotermes sp. 2 (9,58%). A riqueza de espécies foi maior na floresta primária (16 espécies), seguida dos cultivos de dendê (14 espécies) e mandioca (seis espécies). A composição taxonômica e os grupos funcionais também sofreram modificações, sendo mais diversificados e equilibrados na floresta primária quando comparados com os dois tipos de cultivos. A comunidade de cupins é fortemente afetada quando ocorre a substituição da floresta primária pelos cultivos agrícolas. Neste estudo, as espécies N. cf. dendrophilus e H. tenuis merecem atenção, pois se constata o aumento de sua frequência nos cultivos de dendê e mandioca.Frequency, Diversity and Composition of Termite Fauna (Blattodea: Isoptera) in Land Use Systems in the Southwest of Amazonas, Brazil Abstract. Termites are important decomposers of matter of vegetable origin. This study aims to analyze and compare the diversity and composition of termite species in three different land use systems in Alto Solimões, Amazonas, Brazil. Termites were collected in the primary forest, oil palm (Elaeis guineensis Jacq.) and cassava (Manihot sculenta Crantz) crops. In each area the collections were made within a rectangular transect measuring 100 m x 2 m, subdivided into 20 plots of 5 m x 2 m. Twenty four species of termites were found, belonging to 14 genera and two families. The most frequent species were Nasutitermes cf. dendrophilus (Desneux) (28.43%), Heterotermes tenuis (Hagen) (14.37%) and Anoplotermes sp. 2 (9.58%). The species richness was higher in the primary forest (16 species), followed by oil palm (14 species) and cassava (six species) crops. The taxonomic composition and the functional groups were also modified, being more diversified and balanced in the primary forest than in the crops. The termite community was strongly affected when the primary forest was replaced by agricultural crops. The species N. cf. dendrophilus and H. tenuis deserve attention, it was verified the increase of their frequency in the crops.

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Soil Pollution vs. Soil Collembola as a Bioindicator: A review

Journal of Science - JOURNAL OF SCIENCE ◽

10.47944/jos2.5.2018.1 ◽

2010 ◽

Vol 2 (5) ◽

pp. 1-11

Author(s):

Atreyee Sahana

Keyword(s):

Organic Matter ◽

Soil Health ◽

Soil Formation ◽

Terrestrial Ecosystems ◽

Soil Types ◽

Natural Soil ◽

Natural Health ◽

Arthropod Fauna ◽

Mineral Components ◽

Inorganic Mineral

Soil is the foundation of all life activities in terrestrial ecosystems. Soil micro arthropod groups (less than 2 mm in size) like Acari and Collembola comprise more than 90% of arthropod fauna in most soil types. They majorly help in soil formation by breaking up the organic matter and mixing it up with inorganic mineral components. Among them, various species of Collembola have been proved to be effective bioindicator tool to measure soil health either it is polluted or not by its several characteristics in temperate countries. Therefore, in today’s world where pollution in soil by various agents is a baffling issue like other environmental pollutions, these natural soil inhabitants can make a hope to measure the natural health of soil.

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Compositional and chemical characteristics of dissolved organic matter in various types of cropped and natural Chinese soils

Chemical and Biological Technologies in Agriculture ◽

10.1186/s40538-019-0158-z ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Songyan Li ◽

Meng Li ◽

Guoxi Wang ◽

Xiaolei Sun ◽

Beidou Xi ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Soil Type ◽

Spectral Characteristics ◽

Terrestrial Ecosystems ◽

Soil Types ◽

Chemical Characteristics ◽

Natural Soils ◽

Red Soils ◽

Chernozem Soils

Abstract Background Exploration of composition and chemical characteristics of soil dissolved organic matter (DOM) is significant to understand its biogeochemical role in terrestrial ecosystems. A total of 43 cropped and 16 natural soils (0–20 cm) under four soil types (cinnamon, chernozem, red and paddy soils) across China were collected to investigate the spectral characteristics of DOM using UV–Vis and 3D-EEM spectroscopy. Results The chernozem soils exhibited the highest aromaticity and humification degree among the four soil types. Ranges of biological index (BIX, 0.53–1.17) and fluorescence index (FI, 1.55–2.10) were found in the investigated DOM, showing joint contribution from allochthonous and autochthonous sources. Higher BIX and FI in the DOM of the paddy and red soils indicated a greater reliance on autochthonous sources for these two soil types. The cropped soils showed no significant differences in chemical characteristics and sources from the natural soils for the cinnamon, chernozem and red soils. UVA (16.2–47.9%) and UVC fulvic-like substances (15.4–40.5%) were the prevailing DOM components, which were highest in the chernozem soils. Additionally, the cropped soils had a higher proportion of humic-like substances than the natural soils in the DOM. Conclusions Both soil type and land-use strongly affected the chemical characteristics of soil DOM, but only soil type had an impact on the DOM composition for the collected soils. These findings may contribute to the prediction of the biochemical behavior of soil DOM under different soil types and land-uses in terrestrial ecosystems.

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Large-scale genome sequencing of mycorrhizal fungi provides insights into the early evolution of symbiotic traits

Nature Communications ◽

10.1038/s41467-020-18795-w ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 3

Author(s):

Shingo Miyauchi ◽

Enikő Kiss ◽

Alan Kuo ◽

Elodie Drula ◽

Annegret Kohler ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Transposable Elements ◽

Genome Sequencing ◽

Mycorrhizal Fungi ◽

Large Scale ◽

Terrestrial Ecosystems ◽

Pathogenic Species ◽

Fungal Genomes ◽

Induced Genes

Abstract Mycorrhizal fungi are mutualists that play crucial roles in nutrient acquisition in terrestrial ecosystems. Mycorrhizal symbioses arose repeatedly across multiple lineages of Mucoromycotina, Ascomycota, and Basidiomycota. Considerable variation exists in the capacity of mycorrhizal fungi to acquire carbon from soil organic matter. Here, we present a combined analysis of 135 fungal genomes from 73 saprotrophic, endophytic and pathogenic species, and 62 mycorrhizal species, including 29 new mycorrhizal genomes. This study samples ecologically dominant fungal guilds for which there were previously no symbiotic genomes available, including ectomycorrhizal Russulales, Thelephorales and Cantharellales. Our analyses show that transitions from saprotrophy to symbiosis involve (1) widespread losses of degrading enzymes acting on lignin and cellulose, (2) co-option of genes present in saprotrophic ancestors to fulfill new symbiotic functions, (3) diversification of novel, lineage-specific symbiosis-induced genes, (4) proliferation of transposable elements and (5) divergent genetic innovations underlying the convergent origins of the ectomycorrhizal guild.

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Strong warming of subarctic forest soil deteriorated soil structure via carbon loss – Indications from organic matter fractionation

10.5194/soil-2019-41 ◽

2019 ◽

Author(s):

Christopher Poeplau ◽

Páll Sigurðsson ◽

Bjarni D. Sigurðsson

Keyword(s):

Organic Matter ◽

Forest Soil ◽

Soil Structure ◽

Terrestrial Ecosystems ◽

Soil Mass ◽

Soil Warming ◽

Ecosystem Responses ◽

Structure Changes ◽

Northern Latitudes ◽

Fraction Distribution

Abstract. Net loss of soil organic carbon (SOC) from terrestrial ecosystems is a likely consequence of global warming and this may affect key soil functions. Strongest changes in temperature are expected to occur at high northern latitudes, with boreal forest and tundra as prevailing land-cover types. However, specific ecosystem responses to warming are understudied. We used a natural geothermal soil warming gradient in an Icelandic spruce forest (0–17.5 °C warming intensity) to assess changes in SOC content in 0–10 cm (topsoil) and 20–30 cm (subsoil) after 10 years of soil warming. Five different SOC fractions were isolated and the amount of stable aggregates (63–2000 µm) was assessed to link SOC to soil structure changes. Results were compared to an adjacent, previously investigated warmed grassland. Soil warming had depleted SOC in the forest soil by −2.7 g kg−1 °C−1 (−3.6 % °C−1) in the topsoil and −1.6 g kg−1 °C−1 (−4.5 % °C−1) in the subsoil. Distribution of SOC in different fractions was significantly altered, with particulate organic matter and SOC in sand and stable aggregates being relatively depleted and SOC attached to silt and clay being relatively enriched in warmed soils. The major reason for this shift was aggregate break-down: topsoil aggregate mass proportion was reduced from 60.7 ± 2.2 % in the unwarmed reference to 28.9 ± 4.6 % in the most warmed soil. Across both depths, loss of one unit SOC caused a depletion of 4.5 units aggregated soil, which strongly affected bulk density (R2 = 0.91 when correlated to SOC and R2 = 0.51 when correlated to soil mass in stable aggregates). The proportion of water extractable carbon increased with decreasing aggregation, indicating an indirect SOC protective effect of aggregates > 63 µm. Topsoil changes in total SOC and fraction distribution were more pronounced in the forest than in the adjacent warmed grassland soils, due to higher and more labile initial SOC. However, no ecosystem effect was observed in the response of subsoil SOC and fraction distribution. Whole profile differences across ecosystems might thus be small. Changes in soil structure upon warming should be studied more deeply and taken into consideration when interpreting or modelling biotic responses to warming.

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Guild distribution of some termites from cerrado vegetation in south-east Brazil

Journal of Tropical Ecology ◽

10.1017/s0266467400005897 ◽

1991 ◽

Vol 7 (4) ◽

pp. 523-529 ◽

Cited By ~ 25

Author(s):

Terezinha Abreu Gontijo ◽

Denize Junqueira Domingos

Keyword(s):

Organic Matter ◽

Spatial Distribution ◽

Resource Partitioning ◽

Random Distribution ◽

Food Preferences ◽

General Distribution ◽

Nearest Neighbour ◽

Termite Species ◽

Cerrado Vegetation ◽

Distributional Patterns

ABSTRACTThe distributional patterns and food preferences of some cerrado vegetation termites were studied in an area of 2500 m2 in south-east Brazil. All the termitaria were mapped and opened for identification of the species present. Their spatial distribution was studied using the nearest neighbour method (Clark & Evans 1954). We found 46 termite species in 450 nests. The majority of them were wood feeders. The general distribution of termitaria was regular. The distributional patterns of grass and litter feeders were not significantly different from a random distribution. Soil and organic matter feeders were contagiously distributed. The distribution of wood feeders was also contagious. Their spatial distribution was largely influenced by the distribution of the species Nasutitermes sp. 1 and Armitermes euamignathus. These two species occurred in two distinct patches, suggesting resource partitioning.

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Estimating soilpCO2using paleosol carbonates: implications for the relationship between primary productivity and faunal richness in ancient terrestrial ecosystems

Paleobiology ◽

10.1666/11005.1 ◽

2012 ◽

Vol 38 (4) ◽

pp. 585-604 ◽

Cited By ~ 13

Author(s):

Timothy S. Myers ◽

Neil J. Tabor ◽

Louis L. Jacobs ◽

Octávio Mateus

Keyword(s):

Organic Matter ◽

Primary Productivity ◽

Western Europe ◽

Central Africa ◽

Terrestrial Ecosystems ◽

Upper Jurassic ◽

Morrison Formation ◽

Positive Correlation ◽

Terrestrial Environments ◽

Ancient Ecosystems

In this paper we present a method for estimating soilpCO2in ancient environments using the measured carbon-isotope values of pedogenic carbonates and plant-derived organic matter. The validity of soilpCO2estimates proves to be highly dependent on the organic δ13C values used in the calculations. Organic matter should be sourced from the same paleosol profiles as sampled carbonates to yield the most reliable estimates of soilpCO2. In order to demonstrate the potential use of soilpCO2estimates in paleoecological and paleoenvironmental studies, we compare samples from three Upper Jurassic localities. SoilpCO2estimates, interpreted as a qualitative indicator of primary paleoproductivity, are used to rank the Late Jurassic terrestrial environments represented by the Morrison Formation in western North America, the informally named Lourinhã formation in Western Europe, and the Stanleyville Group in Central Africa. Because modern terrestrial environments show a positive correlation between primary productivity and faunal richness, a similar relationship is expected in ancient ecosystems. When the relative paleoproductivity levels inferred for each study area are compared with estimates of dinosaur generic richness, a positive correlation emerges. Both the Morrison and Lourinhã formations have high inferred productivity levels and high estimated faunal richness. In contrast, the Stanleyville Group appears to have had low primary productivity and low faunal richness. Paleoclimatic data available for each study area indicate that both productivity and faunal richness are positively linked to water availability, as observed in modern terrestrial ecosystems.

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Iron-catalysed oxidation and halogenation of organic matter in nature

Environmental Chemistry ◽

10.1071/en14240 ◽

2015 ◽

Vol 12 (4) ◽

pp. 381 ◽

Cited By ~ 19

Author(s):

Peter Comba ◽

Marion Kerscher ◽

Torsten Krause ◽

Heinz Friedrich Schöler

Keyword(s):

Organic Matter ◽

Ozone Depletion ◽

Terrestrial Ecosystems ◽

Formation Mechanisms ◽

Mechanistic Studies ◽

Biomimetic Chemistry ◽

Fenton Chemistry ◽

Volatile Hydrocarbons ◽

Recent Advances ◽

Catalysed Oxidation

Environmental context Natural organohalogens produced in and released from soils are of utmost importance for ozone depletion in the stratosphere. Formation mechanisms of natural organohalogens are reviewed with particular attention to recent advances in biomimetic chemistry as well as in radical-based Fenton chemistry. Iron-catalysed oxidation in biotic and abiotic systems converts organic matter in nature to organohalogens. Abstract Natural and anthropogenic organic matter is continuously transformed by abiotic and biotic processes in the biosphere. These reactions include partial and complete oxidation (mineralisation) or reduction of organic matter, depending on the redox milieu. Products of these transformations are, among others, volatile substances with atmospheric relevance, e.g. CO2, alkanes and organohalogens. Natural organohalogens, produced in and released from soils and salt surfaces, are of utmost importance for stratospheric (e.g. CH3Cl, CH3Br for ozone depletion) and tropospheric (e.g. Br2, BrCl, Cl2, HOCl, HOBr, ClNO2, BrNO2 and BrONO2 for the bromine explosion in polar, marine and continental boundary layers, and I2, CH3I, CH2I2 for reactive iodine chemistry, leading to new particle formation) chemistry, and pose a hazard to terrestrial ecosystems (e.g. halogenated carbonic acids such as trichloroacetic acid). Mechanisms for the formation of volatile hydrocarbons and oxygenated as well as halogenated derivatives are reviewed with particular attention paid to recent advances in the field of mechanistic studies of relevant enzymes and biomimetic chemistry as well as radical-based processes.

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Technical Note: Reactivity of C1 and C2 organohalogens formation – from plant litter to bacteria

Biogeosciences ◽

10.5194/bg-9-3721-2012 ◽

2012 ◽

Vol 9 (10) ◽

pp. 3721-3727 ◽

Cited By ~ 16

Author(s):

J. J. Wang ◽

T. W. Ng ◽

Q. Zhang ◽

X. B. Yang ◽

R. A. Dahlgren ◽

...

Keyword(s):

Organic Matter ◽

Chloral Hydrate ◽

Ecological Impact ◽

Terrestrial Ecosystems ◽

Plant Litter ◽

Technical Note ◽

Organic N ◽

C Stocks ◽

Wide Range ◽

N Pool

Abstract. C1/C2 organohalogens (organohalogens with one or two carbon atoms) can have significant environmental toxicity and ecological impact, such as carcinogenesis, ozone depletion and global warming. Natural halogenation processes have been identified for a wide range of natural organic matter, including soils, plant and animal debris, algae, and fungi. Yet, few have considered these organohalogens generated from the ubiquitous bacteria, one of the largest biomass pools on earth. Here, we report and confirm the formation of chloroform (CHCl3) dichloro-acetonitrile (CHCl2CN), chloral hydrate (CCl3CH(OH)2) and their brominated analogues by direct halogenation of seven strains of common bacteria and nine cellular monomers. Comparing different major C stocks during litter decomposition stages in terrestrial ecosystems, from plant litter, decomposed litter, to bacteria, we found increasing reactivity for nitrogenous organohalogen yield with decreasing C/N ratio. Our results raise the possibility that natural halogenation of bacteria represents a significant and overlooked contribution to global organohalogen burdens. As bacteria are decomposers that alter the C quality by transforming organic matter pools from high to low C/N ratio and constitute a large organic N pool, the bacterial activity is expected to affect the C, N, and halogen cycling through natural halogenation reactions.

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