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The article provides information on the affect of advancing global warming and climate change on the living space of plants and animals including composition of the plant cover change, increasing sea level and change in biodiversity. Topics include change in soil properties, availability of water and nutrients and newly immigrating plant species.

In promiscuous species with sperm storage, males are expected to show a preference for mating with virgin and young females to reduce the risk of sperm competition. In the simultaneous hermaphrodite land snail Arianta arbustorum, sperm production precedes egg production by 2–4 weeks, resulting in a short period of protandric hermaphroditism before shell growth is completed. In natural populations, copulating pairs involving individuals which have not yet completed shell growth (virgins) have been observed. We ran a series of mate-choice experiments to examine whether virgin and nonvirgin (experienced) individuals of A. arbustorumdiscriminate between virgin and nonvirgin mating partners. We also assessed the number of sperm delivered to partners with different mating status. Neither virgin nor nonvirgin snails showed any preference for mating with a virgin partner. In all test situations mating was random and the number of sperm delivered was not adjusted to the mating status of the partner. Mating success was mainly determined by the activity of the individual. The random mating pattern does not imply random fertilization of eggs because the presence of a sperm-digesting organ and the morphology of the sperm storage organ allow a selective storage and use of sperm in A. arbustorum.

Exposed limestone cliffs in the Swiss Jura Mountains harbour a diverse lichen community with some rare species. Sport climbing has recently increased in popularity on these cliffs. We examined the effect of sport climbing on calcicolous lichens by assessing species diversity and cover of lichens in climbed and unclimbed areas of 10 isolated cliffs in the northern Swiss Jura Mountains. We also investigated possible associations between lichens and lichen-feeding land snails on these cliffs. A total of 38 calcicolous lichen species, three bryophytes and one alga were found on the rock faces of 10 cliffs. Twenty lichen species (52.6%) were epilithic, 16(42.1%) endolithic and two (5.3%) foliose. Overall, the epilithic lichen species covered 8.3% of the rock surface, endolithic species 10.2%, and foliose species 0.03%. Climbed and unclimbed rock areas did not differ in total number of lichen species, species density (number of species per 100 cm2) or total lichen cover. However, the frequency of occurrence of epilithic lichens was lower along climbing routes than in unclimbed areas. A multi-response permutation test showed that the lichen community composition of climbed areas differed from that of unclimbed areas. The dissimilarity of lichen communities between climbed and unclimbed areas increased with increasing climbing intensity on the focal route in climbed areas, but not with the age of the climbing route. Five of the 11 snail species recorded on the cliff faces were specialized lichen feeders. Plots along climbing routes harboured fewer snail species than plots in unclimbed areas. Total snail abundance was positively correlated with lichen species richness, but no correlation between snail species richness and lichen species richness was found. Our results indicate that frequent rock climbing can change the lichen community and reduce the snail community of limestone cliffs. A climbing-related reduction of snail abundance may also alter the lichen-herbivore interaction and indirectly change competitive interactions among lichen species.

Alpine grasslands in the Southern Carpathian Mts, Romania, harbour an extraordinarily high diversity of plants and invertebrates, including Carpathic endemics. In the past decades, intensive sheep grazing has caused a dramatic decrease in biodiversity and even led to eroded soils at many places in the Carpathians. Because of limited food resources, sheep are increasingly forced to graze on steep slopes, which were formerly not grazed by livestock and are considered as local biodiversity hotspots. We examined species richness, abundance and number of endemic vascular plants and terrestrial gastropods on steep slopes that were either grazed by sheep or ungrazed by livestock in two areas of the Southern Carpathians. On calcareous soils in the Bucegi Mts, a total of 177 vascular plant and 19 gastropod species were recorded. Twelve plant species (6.8%) and three gastropod species (15.8%) were endemic to the Carpathians. Grazed sites had lower plant and gastropod species richness than ungrazed sites. Furthermore, grazed sites harboured fewer gastropod species endemic to the Carpathians than ungrazed sites. On acid soils in the Fagaras Mts, a total of 96 vascular plant and nine gastropod species were found. In this mountain area, however, grazed and ungrazed sites did not differ in species richness, abundance and number of endemic plant and gastropod species. Our findings confirm the high biodiversity of grasslands on steep slopes in the Southern Carpathian Mts and caution against increasing grazing pressure in these refuges for relic plants and gastropods as well as for other invertebrates.

In many simultaneously hermaphroditic land snail species, the sperm storage organ (spermatheca) is highly structured, suggesting that the female function might be able to influence offspring paternity. Physical properties of the sperm storage organ, including its initial size and sperm storage capacity, may also affect fertilization patterns in multiply mated snails. We examined the structure, volume and tubule length of empty spermathecae in the land snail, Arianta arbustorum, and assessed differences in spermatheca size following a single copulation. The number of spermathecal tubules ranged from 2-7, but was not correlated with the volume of empty spermathecae. The volume of sperm stored in the spermatheca after a copulation was correlated with neither the number of spermathecal tubules nor copulation duration. Mean spermathecal volume more than doubled between two and thirty-six hours after sperm uptake, but the length of the spermathecal tubules did not change. Interestingly, the volume of sperm stored in the spermatheca seems not to be related to the size of the spermatophore and thus not to the number of sperm received (= allosperm). The amount of allosperm digested in the bursa copulatrix was highly variable and no significant relationship with the size of the spermatophore received was found. These findings suggest that numerical aspects of sperm transfer are less important in influencing fertilization success of sperm in A. arbustorum than properties of the female reproductive tract of the sperm receiver.

Animals depend on a large set of essential compounds in their food. However, not all units of food are equal from a nutritional point of view. A reduced supply of protein and calcium might be critical for the growth, reproduction and survival of herbivorous gastropods. We experimentally examined the effects of different protein and calcium supplies on the growth and survival of the land snail Arianta arbustorum. Groups of snails were reared on agar-based diets with each of three levels of protein and calcium (nine treatments). Snails fed a high-protein diet grew faster and reached adulthood earlier and at a larger adult size than snails fed intermediate-and low-protein diets. Surprisingly, the calcium concentration did not affect shell growth and adult size. Snails reared on intermediate- and low-calcium diets increased their consumption rates, but, despite this compensatory feeding, these snails were unable to take up the amount of calcium required for metabolism and shell growth and had a higher mortality. The calcium deficiency could partly be mitigated by the snails' internal calcium storage and reallocation capacity. A depletion of internal calcium reserves adversely affects the entire nutrient metabolism and was the probable cause for the high mortality rates associated with the intermediate- and low-calcium diets observed in the present study.

Sperm competition theory predicts that males exposed to an increased risk of sperm competition should maximize fertilization prospects by inseminating more sperm per ejaculate. We designed a laboratory experiment to examine the effect of increased sperm competition risk on male and female reproductive traits in individuals of the simultaneously hermaphroditic land snail Arianta arbustorum. Courtship behaviour, spermatophore size and number of sperm delivered were not influenced by a higher sperm competition risk. However, snails constantly exposed to mucous trails of conspecifics deposited more egg batches than snails denied any cues from conspecific mucous trails. On the individual level, the number of sperm delivered was positively correlated with the number of eggs produced. This finding contradicts the basic prediction of sex allocation theory that there is a trade-off between resources allocated to male and female function in simultaneous hermaphrodites. Most probably this trade-off may only occur if resources are limited.

The identification of damaged lichens is often difficult due to changes in the morphology of regenerating specimens. We examined the Ultrastructure of grazing damages to four species of calcicolous lichens (Aspicilia calcarea, Physcia adscendens, Tephromela atraand Xanthoria parietina) and free‐living cyanobacteria (family Chroococcaceae) caused by individuals of four species of land snails (Chondrina clienta, Balea perversa, Clausilia bidentataand Helicigona lapicida). We also investigated the radular structure of the four lichen‐feeding snails to examine whether differences in radular morphology result in species‐specific grazing damages. Individuals of all four snail species removed the cyanobacteria layer covering the limestone or lichen surfaces. The four lichen species were grazed to a different extent by the different snail species. SEM‐images showed that B. perversaleft distinct depressions on the thalli of A. calcarea, whereas H. lapicidagrazed off the thalli of this lichen rather evenly. Both snail species left visible radular traces on the lichen surface. In contrast, Ch. clientaleft shallow depressions without radular traces on the thalli of A. calcarea.In Tephromela atra, grazing damages were observed on both thallus and ascocarp. Ascocarps of T. atrawere partly grazed by B. perversa. Helicigona lapicidagrazing on T. atraremoved more or less evenly the entire lichen tissue including the ascocarps. In foliose lichens, grazing by Ch. clienta, B. perversaand Cl. bidentataresulted in depressions of different depths, while H. lapicidaremoved entire pieces of the thalli. In general, radular traces were less distinct in foliose lichens than in crustose lichens.

We modeled the dynamics of a metapopulation of the land snail Arianta arbustorum in north-eastern Switzerland to investigate the effect of population subdivision on the persistence of a land snail metapopulation and to analyze the interaction between spatial factors, population subdivision, and catastrophes. We developed a spatially structured, stochastic, age-structured metapopulation model with field data from previous studies on the metapopulation in Switzerland and experimental and meteorological data. The model incorporated distance-dependent dispersal through stream banks, correlated environmental fluctuations, and catastrophes resulting from heavy rains. The results point to various complex interactions among factors involved in metapopulation dynamics and suggest that in some cases population subdivision may act to decrease threats from environmental fluctuations and catastrophes.

Three species of lichen-grazing snails,Balea perversa, Chondria clienta, andHelicigona lapicida, all from the Swedish island of Öland, were found to sequester lichen compounds when feeding on the crustous lichen speciesAspicila calcarea, Caloplaca flavovirescens, Lecanora muralis, Physcia adscendens, Tephromela atra, andXanthoria parietina. The lichen compounds detected in the soft bodies of the snail species analyzed included the anthraquinone parietin, the depside atranorin, as well as a presumable degradation product of the latter. Other lichen compounds such as (+)-usnic acid or α-collatolic acid were not found in the soft bodies but were only detected in the feces, suggesting selective uptake of lichen compounds by the snails. In individuals ofC. clienta initially fed on the lichenX. parietina, the amount of sequestered parietin decreased over time on a parietin-free diet but was still detectable in the soft bodies after 28 days. In the ovoviviparous land snail,B. perversa, sequestered parietin was transferred from the mother to the eggs in the reproductive tract.

HPLC-analysis was used to determine the concentrations of the lichen compounds alectoronic acid (depsidon), α-collatolic acid (depsidon) and atranorin (depsid) in the lichenized ascomycete Tephromela atra (syn. Lecanon atra ) (Hudson) Hafeliner from limestone walls on the Baltic island of O¨land, Sweden. In 24 individuals of T. atra sampled on a stone wall, the pre-reproductive and reproductive tissue did not differ in the concentrations of alectoronic acid, collatolic acid and atranorin. The concentrations of the three lichen compounds were inter-correlated in the reproductive tissue, but not in the pre-reproductive tissue. Single individuals of T. atra ranged in area covered from 10.1 to 147.4 cm (mean: 38.5 cm; N =24); 38.6% of this area was pre-reproductive tissue. However, the concentrations of the three lichen compounds were correlated neither with the total area covered by the lichen nor with the percentage of pre-reproductive tissue. This suggests that the concentrations of the lichen compounds do not change with increasing size (age) of the lichen. Analysis of specimens of T. atra from eight localities revealed a significant variation in lichen compounds (range between localities: alectoronic acid 0.60-3.26 μg/mg lichen dry weight (DW); collatolic acid 2.14-11.59 μg/mg lichen DW; atranorin 0.58-4.16 μg/mg lichen DW). The level of grazing observed in the lichens differed significantly among localities. However, no correlations between the concentrations of the three lichen compounds and the grazing damage to the lichens were found.

Diastereomers of the spiroacetal, 2,8-dimethyl-1,7-dioxaspiro [5.5]undecane, represent main components of the cephalic secretion from males of the solitary bee,Andrena wilkella. The major compound proved to be of high enantiomeric purity, showing (2S,6R,8S) configuration. Only the naturally occurring enantiomer attracted patrolling males in the field; its antipode was behaviorally inactive and in a racemic mixture did not inhibit response. The (E,Z) diastereomers were also found to be almost inactive. EAG studies gave the same result as the behavioral tests. The biological function of the spiroacetal is discussed in view of the evolution of the mating behavior inA. wilkella.

An experiment was conducted to examine whether extended courtship display (a major component of mating behaviour) or repeated copulation in the course of a reproductive season stimulates egg production in the simultaneously hermaphroditic land snail Arianta arbustorum. Repeated copulation was found to increase the number of eggs produced while courtship display did not appear to affect egg production. However, repeated copulation neither accelerated the onset of egg laying nor increased the hatching success of eggs. These results suggest that reciprocal intromission and/or receipt of a spermato-phore, but not the long-lasting courtship behaviour, stimulates egg production in A. arbustorum.

Reproductive isolation was examined in the simultaneously hermaphroditic, self-incompatible land snail Arianta arbustorum. We tested individuals from two geographically isolated populations in Sweden and three populations in Switzerland. In mate-choice tests, within-population (homotypic) and between-population (heterotypic) meetings occurred among snails in frequencies expected by chance. We found no significant difference in courtship latency and courtship duration between homotypic and heterotypic pairs. However, snails from three populations preferred to mate with homotypic partners. Mating preferences could partly be explained by differences in mating propensity in two out of three populations, but not in matings between a Swedish and a Swiss population. Cross breeding demonstrated a high degree of reproductive compatibility between these two distant populations. In contrast, heterotypic pairs involving two Swiss populations had a reduced fertility. The experimental results indicate that partial premating and postmating isolation may exist between distant populations of A. arbustorum. However, the degree of isolation is not related to the geographical distance between populations.Heredity (1992) 69, 65–72; doi:10.1038/hdy.1992.95

Under natural conditions hatchlings of the land snail Arianta arbustorum cannibalize unhatched sibling eggs as well as eggs from neighbouring batches. Three series of choice experiments were conducted to determine whether cannibalistic hatchlings of A. arbustorum from four different populations discriminate (1) between fertilized and unfertiliz,ed eggs within the same batch, (2) between eggs containing well-developed embryos and ones with less advanced embryos, and (3) between small and large fertilized eggs. Newly-hatched snails did not discriminate between fertilized and unfertilized conspecific eggs. Similarly, hatchlings cannibalized in equal proportions eggs with well-developed embryos and eggs with less advanced embryos. However, cannibalistic hatchlings ate preferentially large eggs. The results of an additional choice experiment indicated that this size preference may be due to a higher encounter probability and/or a stronger attraction by chemical cues of larger eggs, and thus is not an actual choice made by the cannibalistic hatchling. It is suggested that the higher susceptibility of large eggs to cannibalism may act as selection pressure against increasing egg size.

A total of 32 calcicolous lichen species, one alga and one bryophyte were recorded on a limestone wall in the grassland Great Alvar on the Baltic island of Öland, Sweden. Fourteen (41%) of these 34 species and free-living cyanobacteria showed herbivore damage, most probably due to grazing by the land snails Chondrina clienta and Balea perversa which inhabited the limestone wall. Three laboratory experiments were conducted to examine the food preferences of individuals of C. clienta and B. perversa collected at this site and to evaluate any association between their preference and the net food quality of the lichens to the snails. Chondrina clienta and B. perversa exhibited food preferences, which differed significantly between species. Within species, variation in food choice was similar among individuals. This indicates that snail populations may be composed of polyphagous individuals with similar food preferences. Different lichen species were of different net food quality to the snails as indicated by growth rate differences. In both snail species the most preferred lichen species of the choice experiment caused the largest weight increase in juveniles, viz. Caloplaca flavovirescens for C. clienta and Aspicilia calcarea for B. perversa. This suggest that the snail species studied differ in their abilities to deal with secondary compounds and physical characteristics of certain lichens or that they can utilize the energy and nutrients of these lichens to a different extent. It is suggested that differential food preferences might reduce the intensity of interspecific competition for resources (lichens) between C. clienta and B. perversa.

Plant-herbivore interactions may change as atmospheric CO2 concentrations continue to rise. We examined the effects of elevated atmospheric CO2 and CO2-exposure chambers on the grazing damage to plants, and on the abundances of potential herbivores (terrestrial gastropods and grasshoppers) in a calcareous grassland in the Jura mountains of Switzerland (village of Nenzlingen). Individuals of most plant species examined showed slight grazing damage. However, plots with CO2 enrichment and plots with ambient atmosphere did not differ in the extent of grazing damage. Similarly, plots with CO2 enrichment and plots with ambient atmosphere did not differ in either gastropod or grasshopper density. Experimental plots with and without chambers did not differ in the number of gastropods. However, the densities of gastropods and grasshoppers and extent of grazing damage to plants were generally lower in the experimental area than in the grassland outside the experimental field.

Abstract: A laboratory experiment was conducted to determine the damage caused by snail grazing to 35 calcicolous lichen species and cyanobacteria from the Baltic island of Öland, Sweden. Individuals of four species of land snails (Balea perversa, Chondrina clienta, Clausilia bidentata and Helicigona lapicida) were allowed to graze on identified lichen species growing on pieces of limestone. Snail grazing on thalli and ascocarps was classified into four categories ranging from no damage to completely eaten. In general, some lichen species were heavily grazed, whereas others were only slightly damaged or not injured. Aspicilia calcarea, Tephromela atra and Verrucaria nigrescens were preferred by all snail species except Chondrina clienta. In general, lichen thalli that were not immersed in the calcareous rock and cyanobacteria were preferred, whereas ascocarps were avoided by one of the snail species (C. clienta). Immersed perithecia with a carbonized outer layer were avoided by all snail species except C. bidentata. Possibilities of chemical and mechanical defence properties in calcicolous lichens are discussed. Copyright 1993, 1999 Academic Press

Genetic differentiation of the rock-dwelling land snail Chondrina clienta was examined by enzyme electrophoresis in five isolated populations of an outlying area (the Baltic island of Öland, Sweden), and in one population from the species' main range (eastern Alps, Austria). Patterns of allelic variation were compared for 17 putative gene loci involving ten protein systems. All individuals from the five isolated populations on Öland were identically homozygous at all gene loci assayed. Snails from the eastern Alps were homozygous and allelically identical, but they differed by one isozyme band that was absent in animals from Öland and by different alleles fixed at three loci. The absence of isozyme variation and anatomical evidence indicate that self-fertilization may be the prevailing type of reproduction in C. clienta. The allelic identity of the five populations on Öland suggests that they were derived from a single strain, the origin of which probably consisted of one or few self-fertilizing individuals which colonized the island.Heredity (1989) 63, 239–244; doi:10.1038/hdy.1989.97

Morphological investigations showed that the sperm storage organ (spermatheca) of the simultaneously hermaphroditic land snail Arianta arbustorum consists of 2-8 tubules with a common entrance. Sites of sperm storage were examined in snails that mated once (eight individuals) or twice (ten individuals). After one year during which the snails laid eggs only one individual of those which copulated once had some spermatozoa in one spermathecal tubulus. In four snails of those specimens which copulated a second time after one year, a part of the tubules was filled with spermatozoa while in the remaining six animals no spermatozoa were found in the spermatheca, although they received a spermatophore 5 days before fixation. In these latter snails spermatozoa were found exclusively in the sperm-digesting bursa copulatrix. This suggests that the female reproductive system of A. arbustorum may possibly be able to control fertilization by a selective storage of spermatozoa from different mating partners.

Variation in size and nutrient content of eggs deposited in successive batches is a life-history aspect that has received little attention. We examined the size and nutrient content of eggs laid in successive batches by the land snail Arianta arbustorum. Snails from three populations (a lowland, a subalpine and an alpine locality in Switzerland) differed in number of batches produced, clutch size, egg size and nutrient concentration and energy content of eggs. This was partly due to differences in shell size, since reproductive characters of A. arbustorum scale with shell size. In the first batch snails from the lowland and subalpine population laid eggs that had a higher protein concentration (28.1%) than snails from the alpine population (25.6%). Similarly, eggs from the first batch did not differ in carbon concentration in the lowland and subalpine population, whereas eggs from the alpine population had a lower concentration. Clutch size tended to decrease in successive egg batches in all populations. Egg size increased over the reproductive season in snails from the lowland population, whereas no seasonal change was observed in the subalpine and alpine population. Protein concentration decreased in successive batches in the lowland and alpine population but tended to increase in the subalpine population. Carbon concentration decreased over the season in the lowland population but not in the other two populations. This indicates (1) egg characteristics show different changes in successive batches in different snail populations, and (2) the trade-off clutch size vs. egg size can be influenced by alterations of the nutrient concentration and energy content of eggs.

Die Abhängigkeit der Anzahl und Größe der Oozyten von der Körpergröße wurde bei der Kuckucksbiene Nomada lathburiana (Kirby 1802) in einer Population in Mittelschweden untersucht. Die meisten ?? haben 5 Ovariolen in jedem Eierstock, welche im Durchschnitt insgesamt 17.3 reife und beinahe reife Oozyten enthalten. Sowohl die Anzahl als auch die Größe der reifen und beinahe reifen Oozyten ist positiv mit der Größe der ?? korreliert. ??, welche zu verschiedenen Tageszeiten gesammelt wurden, haben gleichviele Oozyten. Die größenabhängige Fekundität in N. lathburiana wird nicht nur wegen der erhöhten Fähigkeit, mehr Eier zu legen, von evolutiver Bedeutung sein, sondern auch wegen der Produktion von größeren Larven, die erhöhte Überlebenschancen haben dürften.

Factors affecting oophagy among siblings in the land snail Arianta arbustorum were studied in 3 populations from different altitudes in Switzerland. The degree of egg cannibalism in A. arbustorum is a function of hatching asynchrony since the earliest hatched snails will devour the unhatched eggs in the same clutch. Clutch size, egg density and amount of vegetable food available to newly hatched snails did not affect the degree of cannibalism. Snails from 3 populations were similar in terms of incubation time and intrinsic hatching asynchrony of the clutches. However, they differed in degree of cannibalism when the hatching asynchrony had been experimentally increased. Snails from a lowland forest showed a higher degree of cannibalism than did those from an alpine mountain slope. The parent snails differed in terms of incubation time and hatching synchrony in their clutches. Under natural conditions, the length of the hatching spread and, as a result, the degree of cannibalism will depend additionally on the mode of oviposition (batches or single; clumped or dispersed), on the spatial heterogeneity of egg-laying places and on climatic conditions (e.g. drought).

Random amplified polymorphic DNA (RAPD) technique was used to analyse the mating system of the simultaneously hermaphroditic land snail Balea perversa and to examine the level of genetic variability in eight natural populations of this rock-dwelling gastropod on the Baltic island of Öland, Sweden. The mode of reproduction was assessed in parent-offspring comparisons, in which parents (virgin at the beginning of the breeding experiment or wild-caught individuals with prior reproductive experience) were kept either singly or in pairs. Snails with no prior reproductive experience produced 1–10 offspring exclusively by selfing, no matter whether they were kept singly or in pairs. In contrast, low rates of outcrossing occurred in snails with prior reproductive experience. Minimum estimates of outcrossing were 10 % for snails kept singly and 16 % for snails kept in pairs. Corresponding maximum likelihood estimates of outcrossing ranged from 16 to 25 %. The results indicated that sperm stored from previous matings were used for cross-fertilization. At the population level, AMOVA analysis showed that most of the genetic variability (84 %) occurred among populations of B. perversa and only 16 % within populations. In two populations genetic variability was completely absent in the DNA fragment patterns examined. This finding agrees with the mode of reproduction in B. perversa. Frequent selfing may account for the low within-population variability compared with the moderate among-population variability in this species.

The article provides information on the preventive measures in national park, Schweizerischer Nationalpark, Switzerland including targeted introduction or accidental introduction of nonnative species, endangerment and displacement of native species and invasive species. Topics include global warming, imports of neophytes and park management.

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