Northern Mid-Atlantic Ridge Hydrothermal Habitats: A Systematic Review of Knowledge Status for Environmental Management

Highly specialised biota occurring at hydrothermally active vents on the northern Mid-Atlantic Ridge (nMAR: from south of Iceland to the Equator) have been the subject of numerous research projects over the 36-year period since these habitats were first discovered in the region. When hydrothermal activity ceases, biota endemic to hydrothermally active habitats are lost, and a new biota colonise these sites. Little is known about the biota colonising hydrothermally inactive sulphide habitats on the nMAR, although these sites may be the target of deep-sea mining within the next decade. In this review, we seek to clarify the current knowledge of biological communities colonising hydrothermally active habitats and inactive sulphide habitats on the nMAR. To achieve this, we (1) used a systematic review process to update the species list of benthic invertebrates associated with hydrothermally active habitats, (2) conducted a regional biogeographic analysis of hydrothermally active vent fields on the nMAR, (3) undertook a comprehensive literature review to provide a descriptive account of biological communities, and (4) identified key knowledge gaps in the current understanding of nMAR hydrothermally active and inactive ecosystems. Our updated species list increases the number of benthic invertebrates recorded from hydrothermally active habitats on the nMAR to 158 taxa. Our regional biogeographic analysis separates nMAR hydrothermal vent fields into distinct clusters based on depth/latitude and chimney composition. Vent fields close to the Azores (Menez Gwen, Lucky Strike, Rainbow) formed a separate cluster from those at greater depths south of the Azores (Broken Spur, TAG, Snake Pit, Logatchev, and Ashadze-1). Moytirra, located north of the Azores, clustered separately, as did Lost City with its unique carbonate chimneys. We present detailed information on the biological communities at hydrothermally active and inactive habitats in this region, and discuss the information available on the diversity, ecosystem function, trophic relationships, connectivity, temporal variability, and resilience and recovery of these communities. Many knowledge gaps still exist, with detailed information needed on all aspects of the biological communities at hydrothermally active habitats and inactive sulphide habitats on the nMAR to understand and predict impacts from natural and human-induced disturbances in the region.

FLORISTIC DIVERSITY OF THE GROUPING AT PISTACIA ATLANTICA IN THE REGION OF NAÂMA (ALGERIA)

Floristic inventory carried out on grouping range at Pistacia atlantica in southern region of Naama makes it possible to identify 135 taxa, divided into 36 families and 105 genera. This large specific diversity, belong to 36 botanical families, best represented (48%) being Asteraceae, Poaceae, Fabaceae and Brassicaceae. The biological analysis shows predominance of Therophytes with 68 species, i.e. 50%. This predominance is characteristic of arid regions vegetation which adapt to saharan and steppe environment. The biogeographic analysis reveals a predominance of three biogeographical types (mediterranean, saharan and endemic) with a rate of 64% or 87 species. This biogeographic distribution reveals floristic heterogeneity and confirms mediterranean affinity of region flora, which combines three sets: high steppe plains, saharan atlas and Saharan border to South.

THE CALAMUS JAVENSIS (ARECACEAE: CALAMOIDEAE) COMPLEX IN HISTORICAL BIOGEOGRAPHIC CONTEXT

ATRIA, M. & VAN WELZEN, P. C. 2021. The Calamus javensis (Arecaceae: Calamoideae) complex in historical biogeographic context. Reinwardtia 20(1): 1−7. — Calamus javensis is a very polymorphic species with a number of recognisable forms (of which several were once even recognized at species level). A historical biogeographic analysis showed no historical distribution pattern in the diversification of these various forms. The forms are very likely the result of adaptation to local circumstances, whereby more or less identical forms can develop under similar niche circumstances in disjunct areas, exceptions are the ‘acuminatus-polyphyllus’ form and C. tenompokensis that are recognisable and present in a non-disjunct area.

ANTS OFSARDINIA: AN UPDATED CHECKLIST BASED ON NEWFAUNISTIC, MORPHOLOGICAL AND BIOGEOGRAPHICAL NOTES

Sardinia is the second largest islandin the Mediterranean region, receiving significant attention due to its interesting fauna and flora. The last checklist of Sardinian ants was published more than a decade ago, and,since then,it got outdated by numerous taxonomic and faunistic novelties. As a result of recentcollecting efforts across theisland,we presentthe first Sardinian records of Messor ibericus Santschi, 1931, Solenopsis lusitanica Emery, 1915(new to Italy), Temnothorax aveli Bondroit, 1918 and Tetramorium atratulum (Schenck, 1852), while proposing to consider Solenopsis fugax (Latreille, 1798)and Temnothorax affinis (Mayr, 1855) as absent. We report for the first time a parasite-host association between Tetramorium atratulum and Tetramoriumsemilaeve André, 1883, and the conspicuous presence of ergatogynes within a Solenopsiscolony (S. lusitanica).Morphological insights on the little-known S. lusitanica and S. orbula Emery, 1875 are also discussed.We combined the new findings and previous literature data intoan updatedchecklist of 77 taxaand discuss afirst biogeographic analysis of the Sardinian antsaided bychorotypes.Eurasian, European, Euro-Mediterraneanand West-Mediterranean taxa are the numerically prevalent groups, while the overall number of speciesis significantly lower than in the other large Mediterranean islands. Considerableknowledge gapsstill remainand some species are known to require additionaltaxonomic investigation

Freshwater Invertebrates of Southwestern South America: Diversity, Biogeography, and Threats

This chapter reviews the current state of knowledge of invertebrates of rivers, lakes, and wetlands in western South America, from southern Peru to the Strait of Magellan in southern Chile. A characterization of the diverse groups of insects, mollusk crustaceans, and other smaller groups is presented, and a biogeographic analysis of them is made with emphasis on their main forcing factors, ecology, and threats in the Anthropocene. This fauna presents Gondwanic characteristics, with clear North–South latitudinal patterns, covering from the Desert of Atacama in the North, one of the most arid deserts of the world, to the rainy and cold regions of the southern end of South America. The central zone of this territory includes one of the global biodiversity “hot spots,” which currently presents serious threats associated with changes in habitat, introduction of invasive species, climate change, and overexploitation of aquatic resources.