Species Of Terrestrial Molluscs Research Articles

Monitoring arthropods under the scope of LIFE-SNAILS project: I - Santa Maria Island baseline data with implementation of the Index of Biotic Integrity.

The database we introduce is a pivotal component of the LIFE SNAILS project (Support and Naturalisation in Areas of Importance for Land Snails). This initiative is dedicated to safeguarding three endangered species of terrestrial molluscs, specifically, two snails (Oxychilusagostinhoi Martins 1981 and Leptaxisminor Backhuys, 1975) and a semi-slug (Plutoniaangulosa (Morelet, 1860)), all of which are single island endemics from Santa Maria Island and face significant threats towards their populations.In this study, we established a comprehensive database derived from a long-term arthropod monitoring campaign utilising SLAM (Sea, Land, Air, Malaise) traps. Although molluscs were not the primary focus, our findings serve as a credible proxy for evaluating the overall habitat quality for endemic invertebrates, with arthropods serving as principal indicators. From September to December of 2022, a total of 11 SLAM traps were installed and monitored monthly in eleven sites of mixed forests of Santa Maria Island. Based on the 33 available samples (11 sites x 3 sampling periods), we recorded a total of 118 taxa of arthropods (of which 94 were identified at species or subspecies level), belonging to three classes, 14 orders and 62 families. From the 94 identified taxa, a total of 21 species were endemic, 31 native non-endemic, 32 introduced and 10 indeterminate. We also provide additional information of the habitat quality (Index of Biotic Integrity), including general habitat and dominant species composition.We registered three new records to the Island, the native bug Piezodoruslituratus (Fabricius, 1794) (Hemiptera, Pentatomidae), the Azorean endemic beetle Phloeosinusgillerforsi Bright, 1987 (Coleoptera, Curculionidae) and the exotic ant Hypoponerapunctatissima (Roger, 1859) (Hymenoptera, Formicidae) and one new record for the Azores Archipelago, the native beetle Cephenniumvalidum Assing & Meybohm, 2021 (Coleoptera, Staphylinidae, Scydmaeninae).This publication not only contributes to the conservation of highly threatened endemic molluscs, through an assessment of habitat quality, based on arthropod communities and habitat description (e.g. native or exotic vegetation), but also provides an updated inventory of arthropods from Santa Maria Island.

Suchozemští plži přírodní rezervace Plané loučky a přírodních památek Častava, Hvězda a Kurfürstovo rameno v CHKO Litovelské Pomoraví [Terrestrial gastropods of Plané loučky Nature Reserve and Častava, Hvězda, and Kurfürstovo rameno Nature Monuments in Litovelské Pomoraví PLA

In 2022, four small-scale protected areas (SPA) within Litovelské Pomoraví Protected Landscape Area were surveyed for terrestrial molluscs. All localities are floodplain forest fragments with oxbow lakes, pools and marshes in the Morava river catchment. The most species-rich SPA was Hvězda Natural Monument (NM), with 38 species recorded. The threatened species Cochlicopa nitens (Endangered), known from this area from previous surveys, was not recorded despite high sampling effort. This sensitive hygrophilous species disappeared probably due to droughts occurring in earlier years. However, other sensitive hygrophilous species such as Euconulus alderi (Nearly Threatened) and Vertigo antivertigo were recorded. The latter was also found in Plané loučky Nature Reserve (NR; 27 spp. in total) and Častava NM (19 spp. in total). Relatively common floodplain forest species Perforatella bidentata was recorded in Plané loučky NR and Hvězda NM; however, it was absent in Častava NM and Kurfürstovo rameno NM (20 spp. in total). The partial absence of this species and the complete absence of substantially declining floodplain species Pseudotrichia rubiginosa (Nearly Threatened) and other sensitive taxa indicate habitat degradation caused mainly by stream regulations and water level decrease and manipulation. The presence of invasive plant species known to decrease terrestrial mollusc species diversity and abundance are of the essence as well. Highly invasive species Arion vulgaris was the most abundant species in all of the surveyed SPAs, except for Hvězda NM, where it was present in lower numbers. Over some twenty years, this species spread from anthropogenic areas to natural habitats to become one of the most prominent features of floodplain biocoenoses in Litovelské Pomoraví and elsewhere. To improve the habitat conservation status, it is important to maintain favourable water level in streams and water bodies adjacent to SPAs, especially during the critical periods of summer droughts. Furthermore, it is advised to focus the management on neophyte extirpation.

Habitat conditions of molluscs in the valleys of the Talaya and Bartat Rivers (Krasnoyarsk forest steppe, Russia) in the middle and late-Holocene

Here we have analysed the Holocene mollusc successions in the valleys of the Talaya and Bartat rivers (Krasnoyarsk forest-steppe), which, based on three radiocarbon dates, cover at least the last 6000 years. By studying more than 8700 mollusc shells, we aimed to reconstruct the development of alluvial conditions. Existing palynological data from the nearby Eleneva Cave provide deeper insights into the reconstruction of habitat conditions. A total of 13 freshwater and 18 terrestrial mollusc species were identified. Some of the land snail species are the first records for the region, with the finding of Vertigo substriata pushing its distribution limit eastward. The Talaya sequence consisted of five successional stages recognised based on Coniss analysis. The major successional pathway in the mollusc record reflects an increase in temperature and fluctuations in precipitation during the Middle Holocene. Over time, an abundant assemblage of freshwater molluscs was gradually replaced by the dominance of open-country and wetland terrestrial snails. In contrast, cooling at the beginning of the Late-Holocene resulted in a reduction in terrestrial snail species diversity at the expense of aquatic molluscs, again indicating increased moisture in riparian habitats. Although the Bartat River succession covered only the last 600 years, it showed a fairly stable mollusc community composition with some terrestrialization observed in the most recent part of the succession.

FORMATION OF BIODIVERSITY OF THE FAUNA OF ECTO- AND ENDOPARASITES ON THE ARARAT PLAIN OF ARMENIA

Our studies were aimed at analyzing biodiversity of ecto- and endoparasites of sheep, cattle, rabbits, domestic birds and dogs in the lowland zone of the Republic, with semidesert climate and height of 850 m above the sea level. This is one of the warm regions of the Republic. The studies performed have established moderate and high degree of animal infection with parasites. We identified 33 parasite species, mostly helminths (15 species), including 10 species of nematodes (Trichocephalus ovis, Nematodirus spathiger, Haemonchus contortus, Chabertia ovina, Dictyocaulus filaria, Muellerius capillaris, Protostrongylus spp., Passalurus ambiqus, Ascaridia galli, Heterakis gallinarum), 4 species of trematodes (Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, Paramphistomum cervi), 1 species of cestodes (Moniezia expansa), 9 protozoan species (Piroplasma bigeminum, Babesia ovis, Eimeria perforans, E. magna, E. irresidua, E. tenella, E. acervulina), 7 species of ticks, 1 species of insects, and 1 species of leishmaniasis vector, the mosquitos from the genus Phlebotomus. We registered 5 species of freshwater molluscs (Lymnaea auricularia, L. stagnalis, L. ovata, L. truncatula, Planorbis planorbis), and 2 species of terrestrial molluscs (Helicella derbentina, Napaeopsis hohenackeri).

DISTRIBUTION AND POPULATION STATUS OF THE SPANISH SLUG IN ZHYTOMYR

In Zhytomyr, the Spanish slug was first discovered in 2018. The study found that the population of Spanish slugs in Zhytomyr occupied an area of 72670 m2. In all cases, numerous plants damage was recorded in the habitats of the Spanish slug. The slugs were located below the leaves and on the soil in the bush of ruderal species. In some cases, their presence could be established by the presence of orange slime on the leaves of the plants. In the study areas, other species of terrestrial molluscs occurred near the Spanish slug: Arion fasciatus (Nilsson, 1823), Arion fuscus (O. F. Müller, 1774), Limax maximus Linnaeus, 1758, Cepaea vindobonensis Ferussac, 1821 and Helix pomatia Linnaeus, 1758.Next year, the area occupied by this population increased to 92300 m2 at the expense of adjacent territories with favorable living conditions. Due to the fact that the spring of 2019 was quite cold, the slugs began to appear only in early May. As in the first population, other species of terrestrial molluscs occurred near the Spanish slug in the studied areas. In addition, a new population of 52790 m2 was discovered in 2019. That is, compared to 2018, the area covered by the invasion of Spanish slugs in Zhytomyr has doubled (145090 m2). Such high growth rates of the area occupied by the population of the Spanish slug, indicate its active settlement in the territory of Zhytomyr. In the near future, it is expected that it will appear in other biotopes suitable for the existence of this species in the city.

Часова динаміка чисельності популяцій молюсків техноземів Нікопольського марганцеворудного басейну

The regularities of the dynamics of terrestrial mollusk populations that have formed on the artificial soil-like structures: on pedozems and sod-lithogenic soils on red-brown clay, gray-green clay and loam loesses-like clays were revealed. The studies were conducted during 2012–2014 years on the remediation station of Nikopol manganese ore basin in Pokrov. Each site within the ranges studied was examined three times a year: in spring (early May), summer (end of June) and autumn (late September - early October). Within tehnozems investigated it was found the presence of four species of terrestrial molluscs: Brephulopsis cylindrica, Monacha cartusiana, Chondrula tridens and Helix lucorum. The number of shellfish in the investigated B. cylindrica biotopes ranges from 3.68 ± 0.43 to 74,55 ± 4 46 ind. / m 2 . The most favorable conditions for this type of snails are formed in the sod-lithogenic soils to gray-green clays and loesses-like clays. A common feature is the tendency to reduce the number of shellfish throughout the year. Number of clam M. cartusiana investigated in habitats in the range from 2.25 ± 0.27 to 18.64 ± 1.08 ind./m 2 . The most favorable conditions for this species of snails are formed in sod lithogenic soils on loam and loesses-like clays on red-brown clays. The general trend is a decrease in the number of shellfish in the summer and the number of stabilization during the summer and autumn. Number Ch. tridens ranges from 1.38 ± 0.20 to 11.90 ± 1.06 ind./m 2 . The greatest population density Ch. tridens for sod-lіtogennih loam soils on loesses-like clays. The seasonal aspect of population dynamics is characterized by the maximum and minimum spring – summer. Mollusk Helix lucorum consistently found in sod-lithogenic soils on loams and often loesses-like clays consistently met in 2012 and 2013. in the biotope at the gray-green clay. The results can be applied to solve problems zoological tehnozems diagnosis. Also a promising area of research is to assess the functional role of terrestrial molluscs community structure mezopedobionts tehnozems. The knowledge of the dynamics of terrestrial molluscs community will help address issues of management functional properties recultozems models.

Měkkýši přírodní rezervace Oheb v Železných horách (východní Čechy) [Molluscs of the Oheb Nature Reserve in the Železné hory Mts. (Eastern Bohemia)

The castle ruin of the Oheb is located above the Seč reservoir in the hilly part of Eastern Bohemia (Czech Republic). The mollusc inventory of this favourable site has already started in the first half of the 20th century (Culek 1944) and has been continuing over the last 50 years (Brabenec 1971, Juřičková 1999). Therefore, the Oheb represents one of the best explored sites in the Czech Republic. The last survey was conducted during the summer 2018 by hand picking and litter sampling at several selected stations. In total, 57 terrestrial mollusc species were recorded during the period 1944–2018. This unusually high species richness is unique, considering relatively poor mollusc fauna of the surrounding area, and represents a classical example of the so-called castle phenomenon. Alinda biplicata, Aegopinella pura, Arianta arbustorum, Helicigona lapicida, Monachoides incarnatus, and Ruthenica filograna were the most frequently recorded species. Arion vulgaris, Oxychilus cellarius, Nesovitrea hammonis, and Malacolimax tenellus have been recorded for the first in 2018 and likely represent modern colonization of the site.

Terrestrial Molluscs in the Dry Grasslands of the DNIPRO Upland (Central Ukraine): New Records, Rare Species and Conservation Potential

Abstract Thirty-six species of terrestrial molluscs were found in the dry grasslands and rock outcrops of the study area, including three that were not previously known for Central Ukraine: Granaria frumentum, Pupilla bigranata and Mediterranea inopinata. These species are relics related to dry open habitats and require conservation in Ukraine on the national level, G. frumentum is already listed in the Red Book of Ukraine, and the other two should be listed in its next edition. It is proposed to create the new protected areas in the most important newly revealed locations of these species. These rocky areas also retain the high diversity of land molluscs in the region. The invasive snail Xeropicta derbentina was found for the first time on the DNIPRO Upland, on the edge of natural dry grassland. The rare native snail Morlina glabra was recorded for the first time in Kyiv Region, it is proposed to be included into the regional red list.

Terrestrial molluscs from the Ontario Far North

From 2009–2014, incidental collections of terrestrial molluscs were made from the Far North of Ontario, Canada. Thirty-four species of terrestrial molluscs were identified from these collections, including one exotic species, Deroceras reticulatum, and three newly reported species from the Far North, Vallonia pulchella, Vertigo cf. genesii, and Gastrocopta similis. Vertigo cf. genesii is newly reported from Ontario. Some species have not been collected in Ontario for many years and some of these only once before. Subnational conservation ranks are discussed for higher-ranked species.

Conservation implications of behavioural interactions between the Giant African Snail and a Native Brazilian species

The Giant African Snail Achatina fulica is widely considered one of the most invasive species in the world. Megalobulimus paranaguensis is a snail endemic to the Brazilian Atlantic Rainforest. Data on possible interactions between A. fulica and terrestrial mollusc species are scarce. We tested whether the presence of A. fulica affects the behaviour of M. paranaguensis. We put three individuals of A. fulica and three individuals of M. paranaguensis in the same aquarium and quantified the time spent in seven behaviours, during three nights (n = 72 individuals for A. fulica and M. paranaguensis). We also tested the effect of sexual maturity, putting juvenile and adult individuals of both species in the same aquarium. We found behavioural differences between species, among individuals exposed to interspecific interactions and in interactions between these factors, but there was no difference in behaviour between juveniles and adults in the same species and between species. Achatina fulica changed its behaviour in interspecific interaction, becoming more active than usual, but M. paranaguensis did not change its behaviour in the presence of the alien species. Our results show that interspecific interaction has an effect on the behavioural patterns of the alien species, and the main factor negatively impacting Megalobulimus populations in Brazil is probably the non-specific control of A. fulica and the alteration and destruction of its habitats.

Composición y estructura en agregaciones de moluscos terrestres en el Complejo de vegetación de mogote, Escaleras de Jaruco, Cuba

Cuba has one of the richest land snail faunas of the world. This important fact has promoted different kind of studies on this group to promote conservation programs, from which many studies have directed their efforts to inventories, and population and community ecology. To contribute with this population knowledge, we studied land snails assemblages in three karstic elevations at the "Escaleras de Jaruco-Tapaste-Cheche" Natural Protected Landscape, Mayabeque, Cuba. We aimed to analyze the variation of the composition and structure of the assemblages between the rainy and little rainy months. The study was conducted from August to November 2009 and from January to April, 2010, in ten permanent square plots (9 m2) separated for over 20 m, on each elevation (Beluca, La Chirigota and La Jaula). In each plot, only live individuals were registered (physiologically active and at rest) to obtain species richness and abundance; besides, temperature (degree C) and relative humidity (%) were also considered in each plot. A total of 4248 individuals were observed which comprised two subclasses, five orders, 11 families, 20 genera and 21 species of terrestrial molluscs. From the total, 19 were Cuban endemics and eight were exclusive from Mayabeque, Matanzas. The Jaula showed the greater riches with 19 species, followed of Beluca with 17, and The Chirigota with 15. In the rainy months, La Jaula, showed individual's greater abundance with 1707, followed of Beluca with 1305 and La Chirigota with 1236. We observed differences in the population density in the three elevations between the rainy and little rainy months, which can be due to the climatic adverse conditions that are shown at the little rainy months. Additionally, during the survey we observed dominance of prosobranch species over the pulmonates. The specific abundance curves showed a steep slope, although was major in the rainy months in relation to the little rain months, which indicates the presence of dominant, common and rare species in the assemblages. In this study, it was demonstrated than the riches and the abundance of land snails in all three elevations, was favored for the elevated relative humidity and the air temperature during the rainy months. These environmental conditions resulted fundamental for the survival of these terrestrial gastropods, as the reproduction and search of food were favored.

Moisture variables, and not temperature, are responsible for climate filtering and genetic bottlenecks in the South African endemic terrestrial mollusc Prestonella (Orthalicoidea)

Non-vagile taxa such as terrestrial molluscs are susceptible to stochastic environmental events that can cause local extinctions or population declines, and extinctions of terrestrial mollusc species are among the highest documented. Many terrestrial snails are habitat specialists, and genetic studies using both allozyme and DNA sequence data have indicated that many species contain substantial and geographically structured genetic variation. In this study, we assess the genetic variation within two species of the rare terrestrial snail genus Prestonella, an inhabitant of rocky areas along water courses in the southern Great Escarpment of South Africa, and correlate genetic diversity to climatic variables. DNA sequence data from mitochondrial 16S rDNA and partial cytochrome oxidase I genes indicate that neither species is monophyletic, and that populations are deeply divergent, even over distances of a few hundred metres. Principal components anaylsis of climatic variables derived from two databases indicates that genetic diversity of the populations is correlated to moisture-related climatic variables. Populations with little or no diversity occur in more arid regions, and are thus most at risk from any future climatic changes that would increase aridification. These moisture variables are thus potent drivers of genetic bottlenecks and may have resulted in historical climate filtering or limitation of the distribution of these species. Temperature appears to be a less important variable, a finding supported by physiological data based on heart rates that show that death occurs only at temperatures far higher than found in their environment.

Terrestrial Mollusc Species Richness and Diversity in Omo Forest Reserve, Ogun State, Nigeria

The terrestrial mollusc species richness and diversity in Omo Forest Reserve, Ogun State, Nigeria, was studied using a combination of direct search and leaf-litter sieving techniques. In total, 28 species and 639 individuals in 7 molluscan families were collected from 17 plots of 400 m2 each. Species richness varied from 3 to 14 (mean 8.59) and the number of individuals from 8 to 67 (mean 37.59) per plot. Species richness was dominated by the carnivorous Streptaxidae (36%) and herbivorous Subulinidae (32%), and numerical abundance by the Subulinidae (56%) and Streptaxidae (32%). The most abundant species was the large subulinid, Subulona pattalus, contributing almost 25% of the total number of individuals. Terrestrial molluscs with small populations and narrow distributional ranges are at great risk of local extinction if forest destruction continues unabated. Studies on the molluscan diversity in Omo Forest Reserve will assist in producing an inventory for biodiversity conservation management in Nigeria.

Malakofauna údolí Tiché Orlice [Mollusc fauna of the Tichá Orlice River valley

Altogether, 78 terrestrial mollusc species were recorded on 31 plots in a stretch of the Tichá Orlice River valley between the cities Choceň and Letohrad (East Bohemia, Czech Republic) in 2007 and 2009. This region harbours 46% of the total terrestrial mollusc fauna of the Czech Republic. The fairly high species richness corresponds to a high habitat diversity and species pool of the region that includes Alpine and Carpathian elements. Of prime conservation importance is a high share of rare and endangered species (EN-2, VU-9, NT-14 species) and species mostly having an isolated population there from the main distribution range. This region is a real hotspot of forest gastropods in Transalpine Europe.

Terrestrial Molluscs of Cabo Delgado and Adjacent Inland Areas of North-Eastern Mozambique

ABSTRACT Nineteen stations were surveyed and 46 species of terrestrial molluscs were recorded from an 18×55 km area in the north-eastern corner of Mozambique. Three stations on Cabo Delgado (a peninsula at the northern extremity of the Quirimbas Archipelago) yielded 19 species that were not found on the inland-sampled area and 18 species that occur inland were not found on Cabo Delgado, with nine species inhabiting both areas. The main ecological difference between Cabo Delgado and the inland area is the abundance of limestone in the former and the total lack of it in the latter. The reference to the original publication, type locality, size of the type specimen(s) and summary geographical distribution as well as colour photographs are provided for each recorded species. One new species of Gulella (Pulmonata: Streptaxidae) is described from Cabo Delgado.

Report on Some Terrestrial Molluscs from Different Regions of Nepal

Nine species of terrestrial molluscs were collected at eastern, mid western and far western regions of Nepal. The documented molluscan samples are represented with 4 families under three orders. Out of the total record of nine species, four species belonged to the family Ariophantidae, three species to Subulinidae, one species to Bradybaenidae and one to Veronicellidae.Key Words: Molluscs; Nepal; record; species; terrestrialJournal of Natural History Museum Vol. 23, 2008 Page 78-81

Mollusks of Albania

The checklist of Albanian mollusks contain 745 species: 345 species of marine molluscs of the Adriatic and Jonian seas, 156 species of freshwater mollusks (included the species of Shkodra, Ohrid and Prespa lakes) and 244 species of terrestrial molluscs, are registered in separate lists. The overview of Albanian mollusks is principally based on the numerous previous lists. It is adjourned with new data from recent publications. Some species, found for the first time in Albania, have been collected during our most recent investigations.

Evaluating reserves for species richness and representation in northern California

ABSTRACTThe Klamath‐Siskiyou forests of northern California and southern Oregon are recognized as an area of globally outstanding biological distinctiveness. When evaluated at a national or global level, this region is often, necessarily, considered to be uniformly diverse. Due to large variation in biotic and abiotic variables throughout this region, however, it is unlikely that biological diversity is uniformly distributed. Furthermore, land management decisions nearly always occur at spatial scales smaller than this entire region. Therefore, we used field data from a random sampling design to map the distribution of local and regional richness of terrestrial molluscs and salamanders within northern California's portion of the Klamath‐Siskiyou region. We also evaluated the protection afforded by reserves established for varying reasons (e.g. for inspiration and recreation for people vs. species conservation) to hotspots of species richness and species representation of these taxa. No existing reserves were created with these taxa in mind, yet it was assumed that reserves established largely around considerations for the northern spotted owl (Strix occidentalis caurina) would afford adequate protection for many lesser‐known species. Species of terrestrial molluscs and salamanders share two general features: (1) they have extremely low vagility, and (2) they are often associated with moist, cool microclimates. Existing reserves disproportionately included areas of hotspots of species richness for both taxa, when hotspots included the richest c. 25% of the area, whereas non‐reserved lands contained greater than expected areas with lower species richness. However, when a more strict definition of hotspot was used (i.e. the richest c.10% of areas), local hotspots for both taxa were not disproportionately found in reserves. Reserves set aside largely for human aesthetics and recreation and those set aside for biodiversity both contributed to the protection of areas with high (greatest 25%) species richness. Existing biodiversity reserves represented 68% of mollusc species and 73% of salamander species, corresponding to the 99th and 93rd percentiles, respectively, of species representation achieved by simulating a random distribution of the same total area of reservation. Cumulatively, however, reserves set aside for inspiration and biodiversity represented 83% of mollusc species and 91% of salamander species. The existing reserves provide conservation value for terrestrial molluscs and salamanders. This reserve network, however, should not be considered optimal for either taxa.

The effects of the slug biological control agent, Phasmarhabditis hermaphrodita (Nematoda), on non-target aquatic molluscs

The nematode Phasmarhabditis hermaphrodita is used as a commercial biological control agent of slugs in the UK. Although it is known to affect other terrestrial mollusc species, its effects on freshwater molluscs are not known. The present study investigated the effects of P. hermaphrodita on the survival of juvenile Lymnaea stagnalis and Physa fontinalis, two common freshwater snails, at ‘spray tank’ concentration and a 50% diluted ‘spray tank’ concentration over a 14-day period. Survival of L. stagnalis was significantly reduced at both application levels but P. fontinalis suffered no mortalities over the experimental period. The possible differential mechanisms of pathology between the two host species are discussed.

Logistic regression models for predicting occurrence of terrestrial molluscs in southern Sweden – importance of environmental data quality and model complexity

We compared the performance of four logistic regression models of different complexity with different environmental data quality, in predicting the occurrence of 49 terrestrial mollusc species in southern Sweden. Performance of models derived from an explanatory data set was evaluated on a confirmatory data set. The overall predictive success of our models (>80% for the three best model approaches), is as good as in other studies, despite the fact that we had to transform a text database into quantitative habitat variables. Simple models (no variable interactions), with forward selection, and detailed habitat data (from field visits) showed the best overall predictive success (mean=84.8%). From comparisons of model approaches, we conclude that data quality (map‐derived data vs habitat mapping) had a stronger impact than model complexity on model performance. However, most of these models showed relatively low values (mean=0.29) for Kappa (statistic for model evaluation), suggesting that the models need to be improved before they would be applied. Predictive success was strongly associated with species incidence but also Kappa was positively correlated with species incidence in univariate tests. Predictive success for true absences was negatively correlated with predictive success for true presences (R2=0.69) and most models failed to give a good prediction of both categories. Models for species with a high incidence in “Open dry sites” or “Mesic interior forests” had a better performance than expected, suggesting that occurrences of species with preference for “narrow” habitats are most easy to predict. Tree layer variables (openness and species abundance) were included in 48 of the 49 final predictive models, suggesting that these variables were good “indicators” of habitat conditions for ground‐living molluscs. Twenty‐four species models included distance to coast and altitude, and we interpret these associations as partly being related to differences in climate. In the final models, true presences (36.9% correctly classified) were much more difficult to predict than true absences (89.7% correct). Possible explanations might be that important habitat variables (e.g. chemical variables and site history) were not included. On the other hand, all suitable sites would not be expected to be occupied due to dynamics in local extinctions (meta‐population theory).