Simple Synthesis of Pyrazole-derived Dithioethers

A number of pyrazole-derived dithioethers were prepared by the reaction of diisothiuronium salts and 2-(3,5-dimethylpyrazol-1-yl)ethanol tosylate in a basic aqueous solution. Diisothiuronium salts were prepared by the reaction of thiourea with alpha,omega-dibromoalkanes containing from two to nine methylene groups. The use of these salts allowed in situ generation ions dithiolate, thus eliminating the need to use hazardous dimercaptans

Description of three new species of Aposphragisma Thoma, 2014 (Araneae: Oonopidae) from Sumatra, Indonesia

Three species from the family Oonopidae are newly described from leaf litter habitats in Sumatra, Indonesia based on male and female morphology. All three species belong to the genus Aposphragisma Thoma, 2014: Aposphragisma globosum sp. n., Aposphragisma jambi sp. n., and Aposphragisma sumatra sp. n

Description of four new species of armoured spiders (Araneae, Tetrablemmidae) from Sumatra, Indonesia

Four new species of armoured spiders from Sumatra, Indonesia are described. Three species are described in the genus Ablemma Roewer, 1963 and one species in the genus Brignoliella Shear, 1978; Ablemma andriana sp. n. (male), Ablemma contrita sp. n. (male and female), Ablemma kelinci sp. n. (male) and Brignoliella patmae sp. n. (male and female). The female of Ablemma singalang Lehtinen, 1981 is described here for the first time. The first record of Brignoliella for Sumatra is also presented

Environmental drivers of local abundance-mass scaling in soil animal communities

The relationship between species' body masses and densities is strongly conserved around a three-quarter power law when pooling data across communities. However, studies of local within-community relationships have revealed major deviations from this general pattern, which has profound implications for their stability and functioning. Despite multiple contributions of soil communities to people, there is limited knowledge on the drivers of body mass–abundance relationships in these communities. We compiled a dataset comprising 155 soil–animal communities across four countries (Canada, Germany, Indonesia, USA), all sampled using the same methodology. We tested if variation in local climatic and edaphic conditions drives differences in local body mass–abundance scaling relationships. We found substantial variation in the slopes of this power-law relationship across local communities. Structural equation modeling showed that soil temperature and water content have a positive and negative net effect, respectively, on soil communities. These effects are mediated by changes in local edaphic conditions (soil pH and carbon content) and the body-mass range of the communities. These results highlight ways in which alterations of soil climatic and edaphic conditions interactively impact the distribution of abundance between populations of small and large animals. These quantitative mechanistic relationships facilitate our understanding of how global changes in environmental conditions, such as temperature and precipitation, will affect community–abundance distributions and thus the stability and functioning of soil–animal communities

Compound-specific isotope analysis of amino acids as a new tool to uncover trophic chains in soil food webs

Food webs in soil differ fundamentally from those aboveground; they are based on inputs from both living plants via root exudates, and from detritus, which is a complex mixture of fungi, bacteria, and dead plant remains. Trophic relationships are difficult to disentangle due to the cryptic lifestyle of soil animals and inevitable microbial contributions to their diet. Compound‐specific isotope analysis of amino acids (AAs) is increasingly used to explore complex food webs. The combined use of AA δ^(13)C and δ^(15)N values is a promising new approach to disentangle trophic relationships since it provides independent but complementary information on basal resources, as well as the trophic position of consumers. We conducted a controlled feeding study in which we reconstructed trophic chains from main basal resources (bacteria, fungi, plants) to primary consumers (springtails, oribatid mites) and predators (gamasid mites, spiders). We analyzed dual compound‐specific isotope AA values of both resources and consumers. By applying an approach termed “stable isotope (^(13)C) fingerprinting” we identified basal resources, and concomitantly calculated trophic positions using ^(15)N values of trophic and source AAs in consumers. In the ^(13)C fingerprinting analysis, consumers in general grouped close to their basal resources. However, higher than usual offsets in AA δ^(13)C between diet and consumers suggest either gut microbial supplementation or the utilization of specific resource fractions. Identification of trophic position crucially depends on correct estimates of the trophic discrimination factor (TDF_(Glu‐Phe)), which was close to the commonly applied value of 7.6‰ in primary consumers feeding on microbial resources, but considerably lower in arachnid predators (~2.4‰), presumably due to higher diet quality, excretion of guanine, and fluid feeding. While our feeding study demonstrates that dual compound‐specific AA analyses hold great promise in delineating trophic linkages among soil‐dwelling consumers and their resources, it also highlights that a “one‐size‐fits‐all” approach to TDF_(Glu‐Phe) does not apply to soil food webs

Functional losses in ground spider communities due to habitat structure degradation under tropical land-use change

Deforestation and land‐use change in tropical regions result in habitat loss and extinction of species that are unable to adapt to the conditions in agricultural landscapes. If the associated loss of functional diversity is not compensated by species colonizing the converted habitats, extinctions might be followed by a reduction or loss of ecosystem functions including biological control. To date, little is known about how land‐use change in the tropics alters the functional diversity of invertebrate predators and which key environmental factors may mitigate the decline in functional diversity and predation in litter and soil communities. We applied litter sieving and heat extraction to study ground spider communities and assessed structural characteristics of vegetation and parameters of litter in rainforest and agricultural land‐use systems (jungle rubber, rubber, and oil palm monocultures) in a Southeast Asian hotspot of rainforest conversion: Sumatra, Indonesia. We found that (1) spider density, species richness, functional diversity, and community predation (energy flux to spiders) were reduced by 57–98% from rainforest to oil palm monoculture; (2) jungle rubber and rubber monoculture sustained relatively high diversity and predation in ground spiders, but small cryptic spider species strongly declined; (3) high species turnover compensated losses of some functional trait combinations, but did not compensate for the overall loss of functional diversity and predation per unit area; (4) spider diversity was related to habitat structure such as amount of litter, understory density, and understory height, while spider predation was better explained by plant diversity. Management practices that increase habitat‐structural complexity and plant diversity such as mulching, reduced weeding, and intercropping monocultures with other plants may contribute to maintaining functional diversity of and predation services provided by ground invertebrate communities in plantations

Rainforest transformation reallocates energy from green to brown food webs.

Terrestrial animal biodiversity is increasingly being lost because of land-use change1,2. However, functional and energetic consequences aboveground and belowground and across trophic levels in megadiverse tropical ecosystems remain largely unknown. To fill this gap, we assessed changes in energy fluxes across 'green' aboveground (canopy arthropods and birds) and 'brown' belowground (soil arthropods and earthworms) animal food webs in tropical rainforests and plantations in Sumatra, Indonesia. Our results showed that most of the energy in rainforests is channelled to the belowground animal food web. Oil palm and rubber plantations had similar or, in the case of rubber agroforest, higher total animal energy fluxes compared to rainforest but the key energetic nodes were distinctly different: in rainforest more than 90% of the total animal energy flux was channelled by arthropods in soil and canopy, whereas in plantations more than 50% of the energy was allocated to annelids (earthworms). Land-use change led to a consistent decline in multitrophic energy flux aboveground, whereas belowground food webs responded with reduced energy flux to higher trophic levels, down to -90%, and with shifts from slow (fungal) to fast (bacterial) energy channels and from faeces production towards consumption of soil organic matter. This coincides with previously reported soil carbon stock depletion3. Here we show that well-documented animal biodiversity declines with tropical land-use change4-6 are associated with vast energetic and functional restructuring in food webs across aboveground and belowground ecosystem compartments

О переносе ряда понятий статистической радиофизики в теорию одномерных точечных отображений

In the article, the possibility of using a bispectrum under the investigation of regular and chaotic behaviour of one-dimensional point mappings is discussed. The effectiveness of the transfer of this concept to nonlinear dynamics was demonstrated by an example of the Feigenbaum mapping. Also in the work, the application of the Kullback-Leibler entropy in the theory of point mappings is considered. It has been shown that this information-like value is able to describe the behaviour of statistical ensembles of one-dimensional mappings. In the framework of this theory some general properties of its behaviour were found out. Constructivity of the Kullback-Leibler entropy in the theory of point mappings was shown by means of its direct calculation for the ”saw tooth” mapping with linear initial probability density. Moreover, for this mapping the denumerable set of initial probability densities hitting into its stationary probability density after a finite number of steps was pointed out. В статье обсуждается возможность использования биспектра при исследовании регулярного и хаотического поведения одномерных точечных отображений. Эффективность трансфера этого понятия в нелинейную динамику продемонстрирована на примере отображения Фейгенбаума. Также в работе рассмотрено применение энтропии Кульбака–Лейблера в теории точечных отображений. Показано, что эта величина информационного характера пригодна для описания поведения статистических ансамблей одномерных отображений. В рамках этой теории выявлены некоторые общие свойства её поведения. Конструктивизм энтропии Кульбака–Лейблера в теории точечных отображений показан также прямым её вычислением для отображения «зуб пилы» с линейным начальным распределением вероятностей. Кроме того, для этого отображения указано счётное множество начальных распределений вероятностей, попадающих в его стационарное распределение вероятностей за конечное число шагов. 

Frontiers in soil ecology—Insights from the World Biodiversity Forum 2022

17 páginas.- 3 figuras.- 194 referenciasGlobal change is affecting soil biodiversity and functioning across all terrestrial ecosystems. Still, much is unknown about how soil biodiversity and function will change in the future in response to simultaneous alterations in climate and land use, as well as other environmental drivers. It is crucial to understand the direct, indirect and interactive effects of global change drivers on soil communities and ecosystems across environmental contexts, not only today but also in the near future. This is particularly relevant for international efforts to tackle climate change like the Paris Agreement, and considering the failure to achieve the 2020 biodiversity targets, especially the target of halting soil degradation. Here, we outline the main frontiers related to soil ecology that were presented and discussed at the thematic sessions of the World Biodiversity Forum 2022 in Davos, Switzerland. We highlight multiple frontiers of knowledge associated with data integration, causal inference, soil biodiversity and function scenarios, critical soil biodiversity facets, underrepresented drivers, global collaboration, knowledge application and transdisciplinarity, as well as policy and public communication. These identified research priorities are not only of immediate interest to the scientific community but may also be considered in research priority programmes and calls for funding.Funding information Deutsche Forschungsgemeinschaft, Grant/Award Numbers: DFG– FZT 118, 202548816, 493345801, DFG, FOR 5000, 192626868, 326061700, MO 412/54‐2; DFG, Grant/Award Numbers: Ei 862/29‐1, Ei 862/ 31‐1; GlobNet project, Grant/Award Number: ANR‐16‐CE02‐0009; Investissement d'Avenir, Grant/Award Numbers: Trajectories: ANR‐15‐ IDEX‐02, Montane: OSUG@2020: ANR‐10‐ LAB‐56; Saxon State Ministry for Science, Culture and Tourism (SMWK), Germany, Grant/Award Number: 3‐7304/35/6‐2021/ 48880; sDiv, Grant/Award Number: SFW9.02; ERC‐StG SHIFTFEEDBACK, Grant/Award Number: 851678; European Union's Horizon 2020 research and innovation programme, Grant/Award Numbers: 864287— THRESHOLD—ERC‐2019‐COG, 817946; Swedish Research Council Formas, Grant/Award Number: 2020‐00807; German Federal Environmental Foundation, Grant/Award Number: DBU, 20021/752Peer reviewe