A new species of Diplostephium (Asteraceae, Astereae) from the Atacama Desert, Chile

A new species, Diplostephiumpaposanum S.T.Ibáñez & Muñoz-Schick, sp. nov., is described for Chile, extending the southern distribution of the genus. Its position within the genus was confirmed by morphological and molecular data, discussed here. The new species was found in a coastal environment, new to the genus, and is geographically far removed from the other Chilean species, which are from the Andes. The formation where it occurs, known as lomas, acts as a biodiversity refuge in hyperarid environments. The presence of D.paposanum in this environment contributes to the evidence of a floristic connection between the Atacama Desert and the Neotropical Andes.

Diversity and Conservation Gap Analysis of the Solanaceae of Southern South America

There is a need to make substantial advances in the taxonomic, systematic, and distribution knowledge of plants, and find better ways of transmission of this information to society to surpass the general pattern described as "plant blindness." The diversity of the plant family Solanaceae reaches its peak in South America; however, many of its species are threatened due to the expansion of the human footprint. Here, we examine the diversity patterns of the family in southern South America (Argentina and Chile) by means of species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE). We also evaluated conservation gaps in relation to protected areas and the human footprint as a proxy for potential impacts on this biodiversity. Results show two richness centers in NW and NE Argentina, with a high degree of overlap with protected areas, which, on the other side, show a relative high index of human footprint. Comparatively, coastal Atacama (Chile) shows lower richness values, but outstanding CWE and WE values. The coast of Atacama harbors high values due the presence of species of the genus Nolana with restricted distributions. Protected areas in this tight coastal strip are sparse, and the human footprint is also relatively high. The degree of protection based on these parameters is then unbalanced, highlighting the need for a geographically explicit strategy for the conservation of the family at subcontinental scale. In doing so, it is likely that other representatives of these unique centers of richness and endemism will benefit.

Living in extreme environments: distribution of Lyciumhumile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America

Very few Solanaceae species are able to grow in saline soils; one of them is Lyciumhumile. This species is endemic to the Altiplano-Puna region (Central Andes, South America) where there are multiple extreme environmental conditions such as hypersaline soils. Here we present an updated description and distribution of L.humile including its new record for Bolivia at the edges of "Salar de Uyuni", the largest salt flat in the world; we discuss its ecological role in saline environments by analyzing soil salinity and cover-abundance values ​​of the studied sites. According to IUCN criteria, we recommend a category of Least Concern for L.humile, but the growing development of lithium mining in saline environments of the Altiplano-Puna region may potentially threaten exclusive communities.

A Fine-Scale Hotspot at the Edge: Epigean Arthropods from the Atacama Coast (Paposo-Taltal, Antofagasta Region, Chile)

Simple Summary

The identification and surveying of fine-scale or micro-hotspots of biodiversity is a crucial strategy for better driving conservation efforts at global hotspots. This seems to be especially relevant at the edges of environments suitable for life, i.e., in desert margins with high levels of endemism, such as the Atacama coast. We surveyed a 100 km section of the Atacama coast including the emblematic Paposo and Taltal sites. We studied the taxonomic composition, richness, and abundance of terrestrial arthropods and were able to identify 173 arthropod species grouped into 118 genera and 57 families. The most abundant orders were Hymenoptera, Coleoptera, and Collembola, which accounted for 90.0% of the total captured. Most abundant families were Melyridae (Coleoptera), Poduridae (Collembola), Tenebrionidae (Coleoptera), and an indeterminate family of Psocoptera. Among remarkable Coleoptera, we were able to register Ectinogonia barrigai (Buprestidae) and Luispenaia paposo (Scarabaeidae). We also documented the presence of the tenebrionid Gyriosomus angustus, and several species of the genera Nycterinus (Paranycterinus) and Scotobius. We also could find the four species of scorpions that have been described for the Paposo area recently, and an undescribed species. The relevance of the area for future prospections and as a conservation site and a fine-scale hotspot of biodiversity has been confirmed based on the epigean arthropods.

Abstract

The Atacama Desert at its margins harbors a unique biodiversity that is still very poorly known, especially in coastal fog oases spanning from Perú towards the Atacama coast. An outstanding species-rich fog oasis is the latitudinal fringe Paposo-Taltal, that is considered an iconic site of the Lomas formation. This contribution is the first to reveal the knowledge on arthropods of this emblematic coastal section. We used pitfall traps to study the taxonomic composition, richness, and abundance of terrestrial arthropods in 17 sample sites along a 100 km section of the coast between 24.5 and 25.5 southern latitude, in a variety of characteristic habitats. From a total of 9154 individuals, we were able to identify 173 arthropod species grouped into 118 genera and 57 families. The most diverse group were insects, with 146 species grouped in 97 genera and 43 families, while arachnids were represented by 27 species grouped into 21 genera and 14 families. Current conservation challenges on a global scale are driving the creation and evaluation of potential conservation sites in regions with few protected areas, such as the margins of the Atacama Desert. Better taxonomic, distributional, and population knowledge is urgently needed to perform concrete conservation actions in a biodiversity hotspot at a desert edge.

Towards Conservation of the Remarkably High Number of Daisy Trees (Asteraceae) in Mexico

Mexico is floristically the fourth most species-rich country in the world, and Asteraceae is the most diverse vascular plant family in this country. The species exhibits a wide range of growth forms, but the tree-like habit, appropriately named daisy trees, is heavily underestimated, even though slightly different tree definitions are handled. Very little is known about their precise species number or conservation status in Mexico, so we update here the list of known Mexican daisy tree species, summarize their very diverse uses, present a general panorama of their present and future distribution, and discuss their conservation status. A bibliographic review and herbarium study were carried out, carefully curated taxonomical ocurrence maps were prepared for each species, and a climatic suitability modelling approach was used to characterise the spatial patterns of Mexican Asteraceae trees. With 149 daisy tree species, the country ranks second at a global level; within the country, their greatest diversity is found in central and western Mexico. A decrease in diversity is estimated in areas that currently host the highest species richness, whereas the hotspot regions are estimated to show an increase in species diversity, so climate change is not a threat to all Mexican daisy tree species.

Taxonomic revision of the Andean genus Xenophyllum (Compositae, Senecioneae)

The Andean genus Xenophyllum (Compositae, Senecioneae) is distributed along the high-Andes from northeastern Colombia to northern Chile and northwestern Argentina, mainly thriving in the paramo and puna ecoregions. It comprises suffruticose plants forming dense mats, hummocks, or clumps of erect stems. They are characterized by displaying involucral bracts fused at the base, supplementary bracts absent, and mostly radiate capitula with white ray corollas, seldom yellow or pink (disciform in one species). Traditionally, Xenophyllum species were treated as members of the genus Werneria, a morphologically close genus that includes rosettiform or scapiform perennial herbs. As currently circumscribed, Xenophyllum mostly differs from Werneria in having elongate stems. Herein, the first modern and comprehensive revision of the genus recognizing twenty-two species and two subspecies is presented. Werneria decumbens is synonymized with X. weddellii, as well as X. fontii with X. humile and X. oscartovarii with X. dactylophyllum. Likewise, four varietal names and two sectional names are proposed as new synonyms. Seven names are lectotypified, the name X. sotarense is epitypified, W. decumbens neotypified, and the supraspecific name W. sect. Integrifoliae Rockh. is typified. The combination X. crassum subsp. orientalecomb. nov. is made. Descriptions and distribution maps are provided for all accepted species, in addition to an identification key. Ten species are illustrated, three of them for the first time.

Rediscovery and taxonomic placement of Solanum polyphyllum Phil. (Solanaceae), a narrow endemic from the Chilean Atacama Desert

Although the original description of Solanum polyphyllum Phil. was made in 1891, this species was not seen until it was re-discovered 128 years later in 2019 in the Atacama Desert. Fruits and seeds were previously unknown and a complete description is provided here. This species was not treated in the most recent monograph of Solanum sect. Regmandra, but it should be incorporated in this section due to its glabrous, sessile and entire leaves, which are decurrent onto the stem. Morphologically, S. polyphyllum is similar to S. paposanum, also of section Regmandra, but differs in the entire leaves (against margins with 4-5 acute lobes in S. paposanum) and glabrous leaves (moderately pubescent adaxially and velutinous abaxially in S. paposanum). The rediscovery of S. polyphyllum at a new locality at the same altitudinal belt as the type, re-affirms its restricted distribution and endemism and supports a potential conservation status as an endangered species.

Synopsis of Schizanthus Ruiz & Pav. (Solanaceae), a genus endemic to the southern Andes

We present a taxonomic synopsis of the South American genus Schizanthus Ruiz & Pav. (Solanaceae), within which we recognise seventeen taxa (14 species with three infraspecific taxa). The genus is mainly distributed in Chile between the coast of the Atacama Desert and the southern temperate forests, while two species occur in the Argentinian Provinces of Mendoza and Neuquén. This taxonomic treatment is based on the analysis of herbarium specimens from 30 different herbaria. For each accepted species we provide details of type specimens and synonymy, key characters, habitat, distribution information and presence in public or private protected areas. We also incorporate a list of representative localities from examined material. We here described three new taxa: Schizanthus porrigens Graham ex Hook. subsp. borealis V.Morales & Muñoz-Schick, subsp. nov., Schizanthus carlomunozii V.Morales & Muñoz-Schick, sp. nov. and its variety Schizanthus carlomunozii var. dilutimaculatus V.Morales & Muñoz-Schick, var. nov., all of them from the coast of Coquimbo Region. We also recognise Schizanthus litoralis Phil. var. humilis (Lindl.) V.Morales & Muñoz-Schick, comb. nov., as a new combination.

Senecio festucoides (Senecioneae, Compositae), a new species from northern Chile

Senecio festucoides is described from northern Chile. The new species is morphologically similar to the discoid caespitose Andean species and belongs to the subgroup displaying yellow corollas and yellowish anthers and style branches. It is characterized by a weak, not self-supporting stem, narrowly linear leaves, long pedunculate capitula with (17-)21 involucral bracts, and minutely papillose achenes. Among other characters, the color of the corollas, anthers, and style branches and the number of involucral bracts differentiate it from S. scorzonerifolius, which is the morphologically closest species. The new species thrives in the desertic Puna ecoregion and grows amongst tufts of Festuca chrysophylla (Poaceae). Detailed pictures of living plants are provided, as well as a distribution map and a dichotomous key to the discoid caespitose Senecio species from northern Chile.

Human-environmental drivers and impacts of the globally extreme 2017 Chilean fires

In January 2017, hundreds of fires in Mediterranean Chile burnt more than 5000 km², an area nearly 14 times the 40-year mean. We contextualize these fires in terms of estimates of global fire intensity using MODIS satellite record, and provide an overview of the climatic factors and recent changes in land use that led to the active fire season and estimate the impact of fire emissions to human health. The primary fire activity in late January coincided with extreme fire weather conditions including all-time (1979-2017) daily records for the Fire Weather Index (FWI) and maximum temperature, producing some of the most energetically intense fire events on Earth in the last 15-years. Fire activity was further enabled by a warm moist growing season in 2016 that interrupted an intense drought that started in 2010. The land cover in this region had been extensively modified, with less than 20% of the original native vegetation remaining, and extensive plantations of highly flammable exotic Pinus and Eucalyptus species established since the 1970s. These plantations were disproportionally burnt (44% of the burned area) in 2017, and associated with the highest fire severities, as part of an increasing trend of fire extent in plantations over the past three decades. Smoke from the fires exposed over 9.5 million people to increased concentrations of particulate air pollution, causing an estimated 76 premature deaths and 209 additional admissions to hospital for respiratory and cardiovascular conditions. This study highlights that Mediterranean biogeographic regions with expansive Pinus and Eucalyptus plantations and associated rural depopulation are vulnerable to intense wildfires with wide ranging social, economic, and environmental impacts, which are likely to become more frequent due to longer and more extreme wildfire seasons.

First record of Ehrharta longiflora Sm. (Poaceae, Ehrharteae) for South America

Ehrharta longiflora Sm. (Poaceae) is recorded for the first time in South America. A few naturalized populations were located in disturbed areas of Valparaíso (Central Chile). A brief taxonomic discussion, images and a location map of the new record of this African grass are provided here.