Hanseniella chilensis is the only myriapod of the class Symphyla known from Chile. This garden centipede, or pseudocentipede, was described more than 120 years ago based on morphologically incomplete ...specimens collected in central Chile, a well-known biodiversity hotspot. In this study, we redescribe this species based on morphologically complete specimens collected near the type locality using scanning electron microscope images. Our study provides the description of diagnostic characters hitherto unknown in this species such as macrochaetae of the tergites and spinnerets of the cerci. We also include a new record from central Chile and discuss the presumed presence of this species in Argentina and Madagascar.
Arid shrublands are spatially heterogeneous environments composed of shrubs patches surrounded by a matrix of bare soil. In this biome, bare soils harbor fewer protist species than soils covered by ...shrubs because they represent low quality habitats for most of them. Furthermore, protist species composition in bare soils often represents a subset of that found in soils covered by shrubs. This pattern suggests that the variability in protist species composition is the result of a non-random mechanism. I performed a nested analysis to test the hypothesis that the source–sink dynamics is shaping the spatial distribution of soil testate amoebae (a polyphyletic group of protists) in an arid shrubland of northern Chile. I found that assemblages of soil testate amoebae are significantly nested in this biome. The species-poor assemblages inhabiting bare soils are thus, only a subset of species-rich assemblages located in vegetated soils. This nested pattern may be the result of a colonization–extinction tradeoff characterized by species-poor bare soils acting as ‘sinks’ maintained by the permanent colonization of individuals coming from species-rich vegetated soils acting as ‘sources’. Thus, the source–sink dynamics represents a valid conceptual framework to explain the spatial patterns of soil protists distribution in arid shrublands.
•A source–sink dynamics shaping protist distribution in arid shrubland is proposed.•Bare soils harbor fewer protist species than vegetated soils in this biome.•Species composition in bare soils was a subset of that found in vegetated soils.•Bare soils acted as ‘sink’ habitats and vegetated soils as ‘source’ habitats.
Research on the diversity and biogeography of Chilean millipedes represents a significant gap in knowledge. To reduce this gap we conducted a study: (1) to investigate the current state of knowledge ...of millipede diversity, and (2) to assess the pattern and causes underlying the latitudinal diversity gradient in Chilean millipedes. In Chile, 95 native millipede species have been recorded. However, rarefaction and extrapolation curves showed that increased sampling effort will reveal more species. An asymptotic estimate of diversity predicted that millipede diversity fluctuates between 125 and 197 species. The estimate, though, was based on a limited data set. Therefore, millipede diversity is probably higher than predicted. Chilean millipedes were categorized as micro-range endemics because they all have latitudinal ranges of less than 1,000 km (with 78% of species exhibiting latitudinal ranges of only ~222 km). Millipede species richness also exhibited a bell-shaped latitudinal diversity gradient, i.e. diversity peaks in the temperate climate of central Chile and decreases towards the arid and polar climates of northern and southern Chile. A multiple regression analysis revealed that this biogeographic pattern is shaped by environmental variables related to water availability, ambient energy inputs and climatic stability. These environmental variables are proxies for two of the five biogeographic hypotheses we tested in this study, i.e. the water-energy balance hypothesis and climatic stability hypothesis. Both hypotheses suggest that millipedes need stable, humid and warm climates to grow, survive and reproduce (niche conservatism). These climatic conditions are only found in central Chile, which is consistent with the diversity peak observed in that region.
is the only myriapod of the class Symphyla known from Chile. This garden centipede, or pseudocentipede, was described more than 120 years ago based on morphologically incomplete specimens collected ...in central Chile, a well-known biodiversity hotspot. In this study, we redescribe this species based on morphologically complete specimens collected near the type locality using scanning electron microscope images. Our study provides the description of diagnostic characters hitherto unknown in this species such as macrochaetae of the tergites and spinnerets of the cerci. We also include a new record from central Chile and discuss the presumed presence of this species in Argentina and Madagascar.
In recent years, electrical systems have evolved, creating uncertainties in short-term economic dispatch programming due to demand fluctuations from self-generating companies. This paper proposes a ...flexible Machine Learning (ML) approach to address electrical load forecasting at various levels of disaggregation in the Peruvian Interconnected Electrical System (SEIN). The novelty of this approach includes utilizing meteorological data for training, employing an adaptable methodology with easily modifiable internal parameters, achieving low computational cost, and demonstrating high performance in terms of MAPE. The methodology combines modified Fuzzy ARTMAP Neural Network (FAMM) and hybrid Support Vector Machine FAMM (SVMFAMM) methods in a parallel process, using data decomposition through the Wavelet filter db20. Experimental results show that the proposed approach outperforms state-of-the-art models in predicting accuracy across different time intervals.
•We investigated the diversity and biogeography of Chilean ciliates, a neglected taxon.•The checklist of Chilean ciliates consists of 207 species including 15 endemic taxa.•Oligohymenophoreans and ...spirotricheans are the best represented taxa in Chile.•Analyses suggest that ∼58–74% of ciliate diversity remains undescribed in Chile.•Chilean ciliates have a biogeographic pattern akin to that of Chilean plants/animals.
There is a significant gap in research and knowledge on the diversity and distribution of Chilean ciliates. To tackle these issues, we used cultures and protargol preparations to describe the ciliates present in poorly explored areas. At these sites, we identified 45 ciliate morphospecies, 35 of which represent unprecedent records to Chile. Then, we brought together our records with literature data to construct a species checklist. This checklist summarises 132 years of data and describes the identity, habitat and distribution of 207 species, including 15 species potentially endemic to Chile. This checklist is far from complete: a diversity estimate suggests that at least two-thirds of the ciliate species occurring in Chile have yet to be described. The checklist is dominated by freshwater taxa because ciliates from marine, brackish and terrestrial environments have rarely been investigated in Chile. Finally, after controlling for sampling artefacts, we found that ciliates exhibit a bell-shaped latitudinal diversity gradient in Chile. This peculiar biogeographical pattern is common in Chile. Plants, animals and testate amoebae also exhibit a bell-shaped latitudinal diversity gradient in Chile. This finding suggests that the historical contingencies that drove the biogeography of the Chilean biota also shaped ciliate biogeography.
•A comprehensive testate amoeba species checklist was constructed for Chile.•In Chile, testate amoeba diversity reaches 64 genera and 352 subgeneric taxa.•89% of species have short latitudinal ...ranges. Only 11% of species are widespread.•About 10% of all testate amoeba species are endemic to Chile.•Testate amoebae meet the diversity patterns observed for Chilean metazoans.
Bringing together more than 170 years of data, this study represents the first attempt to construct a species checklist and analyze the diversity and distribution of testate amoebae in Chile, a country that encompasses the southwestern region of South America, countless islands and part of the Antarctic. In Chile, known diversity includes 416 testate amoeba taxa (64 genera, 352 infrageneric taxa), 24 of which are here reported for the first time. Species−accumulation plots show that in Chile, the number of testate amoeba species reported has been continually increasing since the mid-19th century without leveling off. Testate amoebae have been recorded in 37 different habitats, though they are more diverse in peatlands and rainforest soils. Only 11% of species are widespread in continental Chile, while the remaining 89% of the species exhibit medium or short latitudinal distribution ranges. Also, species composition of insular Chile and the Chilean Antarctic territory is a depauperated subset of that found in continental Chile. Nearly, the 10% of the species reported here are endemic to Chile and many of them are distributed only within the so-called Chilean biodiversity hotspot (ca. 25° S-47° S). These findings are here thoroughly discussed in a biogeographical and evolutionary context.
DIANA, Marta. Buscando el Reino. La opción por los pobres de los argentinos que siguieron al Concilio Vaticano II; Planeta; Buenos Aires; 2013; 515 páginas.
Protists include all eukaryotes except plants, fungi and animals. They are an essential, yet often forgotten, component of the soil microbiome. Method developments have now furthered our ...understanding of the real taxonomic and functional diversity of soil protists. They occupy key roles in microbial foodwebs as consumers of bacteria, fungi and other small eukaryotes. As parasites of plants, animals and even of larger protists, they regulate populations and shape communities. Pathogenic forms play a major role in public health issues as human parasites, or act as agricultural pests. Predatory soil protists release nutrients enhancing plant growth. Soil protists are of key importance for our understanding of eukaryotic evolution and microbial biogeography. Soil protists are also useful in applied research as bioindicators of soil quality, as models in ecotoxicology and as potential biofertilizers and biocontrol agents. In this review, we provide an overview of the enormous morphological, taxonomical and functional diversity of soil protists, and discuss current challenges and opportunities in soil protistology. Research in soil biology would clearly benefit from incorporating more protistology alongside the study of bacteria, fungi and animals.
PDF
