Microhabitat

Collembola, or springtails, are among the most abundant and diverse soil microarthropods. With a true global distribution, these animals are found from the high Arctic to Antarctica, on mountain tops over 5000 m high and in caves as deep as 1760 m. They typically live in soils of forests, meadows, arable fields, (salt) marshes, tundra and deserts, but also in tree canopies, on buildings in cities and some even on the surface of standing water. Springtails graze on litter, fungi, pollen, algae, leaves and roots; they produce faeces that are important in soil formation; they disperse propagules of microorganisms and plants; they interact with other soil fauna, and are food for many soil predators (Hopkin 1997, Rusek 1998). As such they play a central role in soils and soil food webs. Collembola are an ancient group of animals. The first records date back to over 400 MY (Whalley & Jarzembowski 1981). The history of Collembola research is much younger and goes back to Christian Frommann, who in 1684 published an observation of a group of jumping ‘insects’ on snow, and to Carl de Geer, when he described the first four species of ‘Podurae’ in 1740 (http://www.collembola.org/publicat/unavaila.htm). Since then nearly 9000 species of Collembola have been described to date (Bellinger et al. 1996-2020), which likely represents not more than 20 % of the expected existing species (see discussion below). With the current rate of taxonomic descriptions, documenting most of the diversity of Collembola seems hardly feasible within the next decades. On the other hand, technological advances and developing social interactions (e.g. social media, citizen science) may allow us to streamline the taxonomic work across the globe and more closely link it to ecological and evolutionary studies, if applied correctly. Many species have yet to be described, but even more remains to be learned about their biology and ecology. Environmental factors alone have only limited explanatory power when predicting Collembola abundance and community composition (Saraeva et al. 2015, Widenfalk et al. 2016), while biotic interactions and dispersal are difficult to study in the opaque soil environment. Moreover, these factors interact on different spatial and temporal scales (Berg 2012, Heiniger et al. 2014). The small size of most species further complicates ecological studies. Recent experiments and proliferation of genetic and other molecular approaches allowed us to open this black box and advance our understanding of the assembly and functioning of Collembola communities (Auclerc et al. 2009, Chauvat et al. 2014, Chen et al. 2017, Potapov et al. 2016, Zhang et al. 2019). Functional trait approaches, rapidly developing in invertebrate ecology, offer much promise to provide a mechanistic understanding of species occurrences and their ecosystem roles (Krab et al. 2010, Vandewalle et al. 2010, Makkonen et al. 2011, Bokhorst et al. 2012, Salmon & Ponge 2012, Dooremalen et al. 2012, Joimel et al. 2017), but the question remains – which key traits should we measure to understand assembly and functioning of Collembola diversity from a microhabitat to a global scale? Most of the Collembola expertise, both taxonomically as well as ecologically is concentrated in Europe, and the Palaearctic is by far the most well studied biogeographic realm globally for this group of soil fauna. The gap in our knowledge on other zoogeographic regions is likely to bias our perception of the macroecology and evolution of Collembola. Moreover, data on community composition that have already been collected varies greatly according to collection methods, identification quality and are often not available in a structured format. It is clear that we need to agree on better practices of data collection and sharing in the future (White et al. 2020) if we wish to understand the distribution of Collembola on Earth and its fate under global change. Here we reflect on how we can improve our science using past experience, new methods and knowledge we have at our disposal, as well as on where we would like to see Collembola research in 2040. This opinion paper brings together perspectives from classical synthesis and meta-analysis studies on the topics of ecosystem roles of Collembola, conservation of its diversity, feeding behaviour, protection mechanisms and dispersal of different Collembola species, and effects of land use and climate change on collembolan communities; (5) joint efforts in covering the gaps in Collembola knowledge, especially in underexplored regions (predominantly tropics and subtropics) using standard methodologies; (6) data sharing and its integration in open structured databases. We believe that Collembola studies could make use of new technologies and ongoing changes in society. To facilitate the progress across these research topics by 2040, we have established #GlobalCollembola, a distributed-effort community driven initiative that aims to provide open and global data on Collembola taxonomic and genetic diversity, abundance, traits and literature and to coordinate global efforts in covering the key knowledge gaps.

Contact zones of closely related and ecologically similar species constitute rare opportunities to study the evolutionary consequences of past speciation processes. They represent natural laboratories in which strong competition could lead to the exclusion of one species, or the various species may switch into distinct ecological niches. Alternatively, if reproductive isolation has not yet been achieved, they may hybridize. We elucidate the degree of taxon integrity by comparing genetics and habitat use of three similar-sized congeneric viper species,
Vipera ammodytes, Vipera aspis, and Vipera berus, of Nadiza Valley in western Slovenia. No hybridization was detected for either mitochondrial or nuclear genomes. Similarly, external intermediacy by a single prestudy viper (probably V. ammodytes 9 V. aspis) indicates that hybridization occasionally occurs, but should be very rare.
Populations of the three related viperids are partially allopatric in Nadiza Valley, but they also coexist in a narrow contact zone in the montane grassland along the south-exposed slope of Mount Stol (1673 m a.s.l.). Here, the three species that occupy areas in or near patches of rocky microhabitats (e.g. stone piles, slides, and walls) live in syntopy. However, fine-scale measurements of structural components show partial habitat segregation, in which V. berus becomes more dominant at elevations above 1400 m and occupies mostly the mountain ridge and north-exposed slopes of Mount Stol, V. aspis occurs below 1300 m and is the only species to inhabit stoneless
patches of grass and bushes around 1000 m and lower, and V. ammodytes occurs at all elevations up to 1500 m, but is restricted to a rocky microhabitat. We suggest that a high degree of microstructure divergence, slightly different environmental niches, and a generally favourable habitat for all three viper species, keep the pressure for mis-mating and hybridization low, although mechanisms such as reduced hybrid inferiority and temporal mating segregation cannot yet be excluded.

The abundance of Holconia insignis in banana plantations in Cameroon is a matter of concern. However, to date there have been no published studies that specifically synthetize information on the seasonal abundance and biology of H. insignis in banana plantation agroecosystem. In this study we made intensive samplings to study the seasonal response of H. Insignis across different banana plant stratain a banana agroecosystem in Cameroon while the biology of H. insignis was studied in the laboratory. Our results demonstrated that seasonal patterns of H. insignis differed among strata.Female H. insignis attached her egg sacin which she oviposited 238.3 ± 4.2 eggs in loosepeudostems and banana bunches. The female guarded the egg sac until hatching. Females required longer development time than males. Our results underscore the importance of ecology and biology of H. insignisthat facilitate the development of appropriate management for H. insignis.