Small‐scale spatial dynamics of vegetation in a grazed Uruguayan grassland

We explored the small‐scale plant species mobility in a subhumid native grassland subjected to grazing by cattle in south‐western Uruguay. We established four permanent plots of 40 × 40 cm, divided in 16 × 16 cells. In each cell, the presence of species was seasonally recorded for 2 years and annually recorded for 4 years. By nesting the cells, we studied the mobility at different scales, from 6.25 cm² to 400 cm². At each scale we measured species richness, cumulative richness and the turnover rates of the dominant species. We found that the cumulative species richness was an increasing power function, with higher accumulation rates with smaller spatial scale. Although species richness showed seasonal fluctuations, the mean species richness was constant during the study period. We detected significant spatio‐temporal variability in mobility patterns among species. Certain species showed a high capacity to colonize new sites, whereas other species rotate among sites that they previously occupied. Grazed communities in Uruguayan Campos are structured as a dense matrix of perennials grasses and forbs, where vegetative propagation is the main form of growth of the species. The small‐scale dynamics and the high variability in the mobility characteristics could be linked with the diversity of growth forms and spatial strategies of the species in this community. We believe that a high degree of small‐scale spatial dynamics contribute to explain the species coexistence and the apparent stability of communities at local scales.     

Seeding tallgrass prairie in monospecific patches promotes native species establishment and cover

In tallgrass prairie reconstruction, the way desired seeds are arranged on the landscape may affect species establishment, species persistence, and the establishment and persistence of undesired (nonseeded) species from the local propagule pool. To test effects of species seeding pattern on how grasslands develop spatially, we seeded 20—4 × 4–m bare soil plots with 16 tallgrass prairie species. Treatment plots were divided into 16—1 × 1–m subplots, 64—0.5 × 0.5–m subplots, 256—0.25 × 0.25–m subplots, or 1,024—0.125 × 0.125–m subplots. Each species was hand broadcast into separate subplots (1 m² total area/species) within each plot. An additional treatment included uniformly mixing and broadcasting all seeds across a plot. We recorded species cover at the 0.125 × 0.125–m scale within each plot at the beginning of the second and third growing seasons. While species persistence was greatest within plots seeded with larger subplots, plots with smaller subplots were more spatially diverse and less occupied by nonseeded species over time than larger subplot and mixed plots. As is common in reconstruction efforts, establishment was variable among species and seeding with monospecific subplots enhanced colonization of desired rhizomatous species (e.g., Heliopsis helianthoides, Monarda fistulosa, Elymus virginicus) into unoccupied locations at the expense of species from the local propagule pool. Results suggest that seeding species in smaller, monospecific patches could result in grasslands with a more balanced native species composition than those established with a seed mixture approach.     

Functional diversity versus species diversity: relationships with habitat heterogeneity at multiple scales in a subtropical evergreen broad-leaved forest

Understanding the relationship between functional and species diversity as well as their association with habitat heterogeneity can help reveal the mechanisms of species coexistence in ecological communities. However, these interactions have been poorly studied in subtropical forests. In this paper, we evaluated functional diversity (as measured by Rao’s Q) and traditional species diversity (based on Simpson’s index) in a 24 ha forest plot in a subtropical evergreen broad-leaved forest (EBLF) in China. We compared the sensitivities of functional and species diversity to topographic variables (elevation, convexity, slope and aspect) at multiple spatial scales based on 10 × 10, 20 × 20, 40 × 40 and 50 × 50 m quadrats. Functional and species diversity were found to have different distribution patterns along a topographical gradient, with functional diversity better explained by topography than was species diversity using a spatial autocorrelation regression error model. Furthermore, functional diversity had a significantly greater association with topographic variables than species diversity in both adult and young trees; in both cases, the strength of the diversity-habitat association increased with quadrat size. We conclude that functional diversity reflects a greater diversity-habitat association in EBLF than does species diversity, and that the association depends on the spatial scale and life stages of the woody plants under evaluation.     

Colonization dynamics of a clonal pioneer plant on a glacier foreland inferred from spatially explicit and size-structured matrix models

The regional distribution of a plant species is a result of the dynamics of extinctions and colonizations in suitable habitats, especially in strongly fragmented landscapes. Here, we studied the role of spatial dynamics of the long-lived, clonal pioneer plant Geum reptans occurring on glacier forelands in the European Alps. We used demographic data from several years and sites in the Swiss Alps in combination with dispersal data to parametrize a matrix model for G. reptans to simulate extinctions, colonizations and spatial spread of established populations on glacial forelands. We used different scenarios with varying germination rates, wind and animal dispersal capabilities, and modes of spatial spread (seed-only vs clonal spread), resulting in population growth rates (λ) ranging from 1.04 to 1.20. Our results suggest that due to the low germination rate (~1%) and the very limited wind dispersal distances (99.8% of seeds are dispersed < 5 m), G. reptans has a low probability of establishing new populations and a very low spatial spread by seed dispersal alone. In contrast to the low rate of establishment, the persistence of established populations is high and even populations of only a few individuals have an extinction probability of less than 25% within 100 years. This high persistency is partly due to clonal reproduction via aboveground stolons. Clonal reproduction increases the population size and contributes considerably to the spatial spread of established populations. Our simulation results together with the known pattern of molecular diversity of G. reptans indicate that the occurrence of populations of this species in the Alps is unlikely to be a result of recent colonizations by long-distance dispersal, but rather a result of post-glacial colonizations by large migrating populations that were fragmented when glaciers retreated. Additionally, our simulations suggest that the currently observed high rates of glacial retreat might be too fast for pioneer plants, such as G. reptans, to keep up with the retreating ice and therefore might threaten existing populations.     

Small-scale spatial dynamics of plant species in a grassland community over six years

Abstract. In a species-rich mountain grassland in the Krkonosse Mts., Czechoslovakia, data from four permanent plots of 50 cm x 50 cm were recorded annually from 1985 to 1990 to study the spatial dynamics of the species. Plots were divided into 15 x 15 subplots and the number of vegetative units of all plants within each subplot was determined. There was not much net change at the plot level, but the subplots were very dynamic. Two aspects of the spatial dynamics of the species were followed: (1) persistence, i.e. the tendency of the species to remain in the same subplot, and (2) long-distance spreading, i.e. movement to subplots beyond the immediate neighbourhood. Species differed widely in their persistence and longdistance spreading and were classified into mobility types: long-range guerrilla, short-range guerrilla, phalanx and 'sitting’. The mobility types were, to a certain extent, correlated with the growth form of plants, but some species of one growth form showed different types of small-scale dynamics and some species with different growth forms had the same spatial dynamics.     

Resting in risky environments: the importance of cover for wolves to cope with exposure risk in human-dominated landscapes

Centuries of persecution have influenced the behaviour of large carnivores. For those populations persisting in human-dominated landscapes, complete spatial segregation from humans is not always possible, as they are in close contact with people even when they are resting. The selection of resting sites is expected to be critical for large carnivore persistence in human-dominated landscapes, where resting sites must offer protection to counteract exposure risk. Using wolves (Canis lupus) as a model species, we hypothesised that selection of resting sites by large carnivores in human-dominated landscapes will be not only influenced by human activities, but also strongly determined by cover providing concealment. We studied the fine-scale attributes of 546 wolf resting sites and confronted them to 571 random points in NW Iberia. Half of resting sites (50.8 %) were found in forests (mainly forest plantations, 73.1 %), 43.4 % in scrublands, and only 5.8 % in croplands. Compared to random points, wolves located their resting sites far away from paved and large unpaved roads and from settlements, whereas they significantly selected areas with high availability of horizontal (refuge) and canopy cover. The importance of refuge was remarkably high, with its independent contribution alone being more important than the contribution of all the variables related to human pressure (distances) pooled (51.1 vs 42.8 %, respectively). The strength of refuge selection allowed wolves even to rest relatively close to manmade structures, such as roads and settlements (sometimes less than 200 m). Maintaining high-quality refuge areas becomes an important element to favour the persistence of large carnivores in human-dominated landscapes as well as human-carnivore coexistence, which can easily be integrated in landscape planning.     

Clustering of plant life strategies on meso-scale

The spatial pattern of life strategies gives us clues about what factors are important for structuring the vegetation and at which scale they work. In this study, we look at the spatial distribution of the CSR-strategies of Grime on a meso-scale (larger than 50 m × 50 m) in a temperate forest. To detect the spatial pattern of the different life forms, 79 plant species were surveyed according to a grid with 2431 cells of 50 m × 50 m. For each cell C, S and R-values were calculated and their spatial distribution was studied. The spatial patterns were then explained by available environmental factors. The different plant strategies clearly showed an aggregated pattern on a scale larger than 50 m × 50 m. This non-random and unequal distribution of the different life strategies could be explained by the factors that are under the control of the forest management, namely “distance to road” and “dominant (planted) tree species”. Patches with high C-values (C-biotopes) where found under pine, S-biotopes where found under mixed oak-beech and pure beech stands of 100 to 150 years old. R-biotopes were bound to the roads.     

The impact of forest continuity and management on forest floor vegetation evaluated by species traits

The distribution of the flora with different species attributes are investigated in two studies of forest ecosystems in Denmark, One study compared 17 forests with different degrees of management, the other study compared the flora of 25 old forests with that of 6 new forests. No effect of forest management could be detected in the distribution of species attributes in the flora, whereas the forest continuity was correlated with almost all of the 14 traits investigated. Species with heavy seeds, transient seedbanks, ant dispersed seeds, early and short flowering time, low stature and high extent of lateral spread were more common in old forests, while the proportion of species with small, short-lived seeds, epizoochorous dispersal, little lateral spread and later and longer flowering period was higher in new forests. In particular, Raunkiaers therophyles, and ruderal species were more common in new forests than in old.
Differences in the effects of the two types of disturbance - forest management, and breaks in forest eontinuity - are discussed in relation to survival strategies of the forest flora. The importanee of persistence ability in contrast to colonisation ability is stressed for many forest plants.     

Modelling chorotypes of invasive vertebrates in mainland Spain

We investigated the existence of chorotypes – assemblages of species with similar geographical ranges – of invasive species in a host territory, and their potential use to advocate similar control or management strategies for species in the same chorotype. We analysed the distribution of 13 exotic terrestrial vertebrate species (six birds, six mammals, and one reptile) with well‐known distributions in mainland Spain. We used the presence/absence data on a grid of 10 km × 10 km UTM cells from the Atlases of terrestrial vertebrates of Spain. These data were aggregated to a grid of 50 km × 50 km UTM cells, because it entailed no loss of meaningful information and allowed dealing with a much lower number of cells. Using cluster analysis and a probabilistic assessment of the classification, we identified seven significant chorotypes: four multispecific and three monospecific. The compound chorotypes grouped together species that tended to share certain characteristics about their introduction, release cause, establishment, and spread. We modelled the chorotypes using a favourability function based on a generalized linear model and 31 variables related to spatial situation, topography, lithology, climatic stability, energy availability, water availability, disturbances, productivity, and human activity. Climatic factors affected the favourability for every chorotype, whereas human variables had a high influence in the distribution of three chorotypes involving eight species. On the basis of these variables, we identified favourable areas for all the chorotypes in mainland Spain. The favourability for a chorotype in an area may be a useful criterion for evaluating the local conservation concern due to the whole set of species. Favourable but unoccupied areas can be used to infer possible colonization areas for each chorotype. We recommend using chorotypes to optimize broad‐scale surveillance of invasive species.     

Effect of cattle activities on gap colonization in mountain pastures

Cattle influences gap dynamics in pastures in two ways: (1) by creating gaps and (2) by affecting the colonization process. This effect of cattle activity on gap revegetation can be subdivided in three main factors: herbage removal, trampling and dung and urine deposition. The objective of this study was to assess how these three effects moderate the plant succession following gap creation. In an exclosure, four controlled treatments simulating cattle activity (repeated mowing, trampling, manuring and untreated control) were applied on plots of 2 × 2 m. In the centre of each plot, one artificial gap of 60 × 60 cm was created. During three years, vegetation changes were monitored in spring and in autumn, with a square grid of 100 cells of 0.01 m² centred on the gap. Our experiment confirmed that fine-scale gap creation may have a high impact on relative abundances of species in the community. The gap environment acts on species as a filter and this filtering was described in terms of regenerative attributes. Colonizers were species with small seeds, unspecialized seed dispersal, persistent seed bank and high vegetation spread. However, the role of dung deposition, herbage removal or trampling by cattle did not seem to be of primary importance in the revegetation process, but could moderate vegetation response. Therefore, the different cattle effects act as secondary filters that selectively favoured or disadvantaged different species from the gap-regenerating community. These complex interactions are probably keys to understand plant coexistence in perennial grasslands.     

Spatial and temporal genetic structure in a hybrid cordgrass invasion

Invasive hybrids and their spread dynamics pose unique opportunities to study evolutionary processes. Invasive hybrids of native Spartina foliosa and introduced S. alterniflora have expanded throughout San Francisco Bay intertidal habitats within the past 35 years by deliberate plantation and seeds floating on the tide. Our goals were to assess spatial and temporal scales of genetic structure in Spartina hybrid populations within the context of colonization history. We genotyped adult and seedling Spartina using 17 microsatellite loci and mapped their locations in three populations. All sampled seedlings were hybrids. Bayesian ordination analysis distinguished hybrid populations from parent species, clearly separated the population that originated by plantation from populations that originated naturally by seed and aligned most seedlings within each population. Population genetic structure estimated by analysis of molecular variance was substantial (F_ST=0.21). Temporal genetic structure among age classes varied highly between populations. At one population, the divergence between adults and 2004 seedlings was low (F_ST=0.02) whereas at another population this divergence was high (F_ST=0.26). This latter result was consistent with local recruitment of self-fertilized seed produced by only a few parental plants. We found fine-scale spatial genetic structure at distances less than ∼200 m, further supporting local seed and/or pollen dispersal. We posit a few self-fertile plants dominating local recruitment created substantial spatial genetic structure despite initial long-distance, human dispersal of hybrid Spartina through San Francisco Bay. Fine-scale genetic structure may more strongly develop when local recruits are dominated by the offspring of a few self-fertile plants.     

荧光原位杂交在喀斯特山地土壤硫酸盐还原菌检测中的应用

采用荧光原位杂交(Florescence in situ Hybridization,FISH)技术分析了喀斯特山地土壤硫酸盐还原菌(SRB)的数量和空间分布状况.运用16S rRNA特异性探针,结合DAPI全细胞染色和样品稀释,FISH技术准确、高效地原位检测出土壤剖面中SRB的数量和分布状况.结果显示,在所研究的土壤剖面各层均有SRB检出,最低为(0.8±0.4)×107个/g,最高为(6.2±1.3)×107个/g,平均为(2.7±1.2)×107个/g.FISH能同时对土壤中的SRB进行定性和定量分析,是研究环境中SRB时空分布的快速有效的检测技术.     

A functional analysis of a limestone grassland community

Abstract. We examine the potential of standardised data, mainly collected in the laboratory, to elucidate mechanisms of species coexistence, using a south-facing, infertile, species- rich limestone grassland at Miller's Dale, Derbyshire, England as a model system. Standardised autecological data for 15 of the more important Miller's Dale species were obtained from the Integrated Screening Programme (ISP), and their functional attributes were reviewed in the context of a larger database, broadly representative of the British flora. Ordination of adult plant attributes demonstrated that the Miller's Dale species are strategically relatively uniform; most are slow-growing, evergreen and tolerant of mineral nutrient deficiency. Ordination of seed attributes revealed more variety among the Miller's Dale species; the main axis of variation was from species with large, transient seeds (mostly grasses) to species with small, persistent seeds (mostly dicots). From the ordination we derive the predictions that germination of the latter species will be more temporally opportunistic and more inhibited by the presence of vegetation than the former. These predictions are consistent with data collected in experimental studies of seed persistence and germination at the site. These data suggest that spatial and temporal variation in opportunities for regeneration is an important mechanism contributing to the high species richness of dry limestone grasslands.     

Extensive long-distance pollen dispersal and highly outcrossed mating in historically small and disjunct populations of Acacia woodmaniorum (Fabaceae), a rare banded iron formation endemic

Background and Aims

Understanding patterns of pollen dispersal and variation in mating systems provides insights into the evolutionary potential of plant species and how historically rare species with small disjunct populations persist over long time frames. This study aims to quantify the role of pollen dispersal and the mating system in maintaining contemporary levels of connectivity and facilitating persistence of small populations of the historically rare Acacia woodmaniorum.

Methods

Progeny arrays of A. woodmaniorum were genotyped with nine polymorphic microsatellite markers. A low number of fathers contributed to seed within single pods; therefore, sampling to remove bias of correlated paternity was implemented for further analysis. Pollen immigration and mating system parameters were then assessed in eight populations of varying size and degree of isolation.

Key Results

Pollen immigration into small disjunct populations was extensive (mean minimum estimate 40 % and mean maximum estimate 57 % of progeny) and dispersal occurred over large distances (≤1870m). Pollen immigration resulted in large effective population sizes and was sufficient to ensure adaptive and inbreeding connectivity in small disjunct populations. High outcrossing (mean t_m = 0·975) and a lack of apparent inbreeding suggested that a self-incompatibility mechanism is operating. Population parameters, including size and degree of geographic disjunction, were not useful predictors of pollen dispersal or components of the mating system.

Conclusions

Extensive long-distance pollen dispersal and a highly outcrossed mating system are likely to play a key role in maintaining genetic diversity and limiting negative genetic effects of inbreeding and drift in small disjunct populations of A. woodmaniorum. It is proposed that maintenance of genetic connectivity through habitat and pollinator conservation will be a key factor in the persistence of this and other historically rare species with similar extensive long-distance pollen dispersal and highly outcrossed mating systems.     

Quantifying habitat structure: surface convolution and living space for species in complex environments

Habitat complexity is often used to explain the distribution of species in environments, yet the ability to predict outcomes of structural differences between habitats remains elusive. This stems from the difficulty and lack of consistency in measuring and quantifying habitat structure, making comparison between different habitats and systems problematic. For any measure of habitat structure to be useful it needs to be applicable to a range of habitats and have relevance to their associated fauna. We measured three differently‐shaped macrophyte analogues with nine indices of habitat structure to determine which would best distinguish between their shape and relate to the abundance and rarefied species richness of their associated macroinvertebrate assemblages. These indices included the physical, whole‐plant attributes of surface area (SA) and plant volume (PV), the interstitial space attributes of average space size and frequency (ISI), average refuge space from predation (Sp/Pr), and total refuge space (FFV), and the degree of surface convolution at a range of scales (i.e. the fractal dimension at four spatial scales: 7.5×, 5×, 2.5× and 1× magnification). We found a high degree of inter‐correlation between the structural indices such that they could be organised into two suites: one group describing interstitial space and surface convolution at coarse scales, the other describing whole‐plant attributes and surface convolution at fine scales. Two of these indices fell into both suites: the average refuge space from predation (Sp/Pr) and the fractal dimension at 5× magnification. These two measures were also strongly related to macroinvertebrate abundance and rarefied species richness, which points to their usefulness in quantifying habitat structure and illustrates that habitat structure depends not just on shape, but on the space associated with shape.     

Fine‐scale persistence of boreal bog plants

Abstract. Persistence, or the tendency of a species to remain in its original position without colonizing new sites, is studied for 24 species on the ombrotrophic Northern Kisselbergmossen in SE Norway. Data sets comprise presence/absence in 436 sample plots (16 cm x 16 cm) and 6976 subplots (4 cm x 4 cm) analysed with a 5‐yr interval. Persistence was calculated for both spatial scales, and the observed values were compared with null models of completely random presence/absence of species. Species characteristics (plot occurrences and persistence) were related to depth to the water table and species optima along ecologically interpreted DCA ordination axes. The observed persistence was significantly higher than predicted from the random model for all vascular plants and cryptogams at both spatial scales. All taxonomic groups showed higher persistence at the sample plot scale than at the subplot scale. No general relationship between persistence and depth to the water table was found, but for the cryptogams there was somewhat higher persistence for the less peat‐producing species. The persistence of the vascular plants depended on ramet longevity, growth form and vegetative mobility. In general, the observed persistence of most cryptogams was high, probably because of their perenniality, low growth rates and high reproductive output. Differences in growth‐form and life history, as well as the higher number of occurrences, are the most likely reasons for somewhat higher mean persistence of hepatics and Sphagna than of vascular plants at the subplot scale.     

Comparable ecological dynamics underlie early cancer invasion and species dispersal, involving self-organizing processes

Occupancy of new habitats through dispersion is a central process in nature. In particular, long-distance dispersal is involved in the spread of species and epidemics, although it has not been previously related with cancer invasion, a process that involves cell spreading to tissues far away from the primary tumour.Using simulations and real data we show that the early spread of cancer cells is similar to the species individuals spread and we suggest that both processes are represented by a common spatio-temporal signature of long-distance dispersal and subsequent local proliferation. This signature is characterized by a particular fractal geometry of the boundaries of patches generated, and a power-law scaled, disrupted patch size distribution. In contrast, invasions involving only dispersal but not subsequent proliferation (“physiological invasions”) like trophoblast cells invasion during normal human placentation did not show the patch size power-law pattern. Our results are consistent under different temporal and spatial scales, and under different resolution levels of analysis.We conclude that the scaling properties are a hallmark and a direct result of long-distance dispersal and proliferation, and that they could reflect homologous ecological processes of population self-organization during cancer and species spread. Our results are significant for the detection of processes involving long-range dispersal and proliferation like cancer local invasion and metastasis, biological invasions and epidemics, and for the formulation of new cancer therapeutical approaches.     

Predicting Microstegium vimineum invasion in natural plant communities of the southern Blue Ridge Mountains, USA

Shade-tolerant non-native invasive plant species may make deep incursions into natural plant communities, but detecting such species is challenging because occurrences are often sparse. We developed Bayesian models of the distribution of Microstegium vimineum in natural plant communities of the southern Blue Ridge Mountains, USA to address three objectives: (1) to assess local and landscape factors that influence the probability of presence of M. vimineum; (2) to quantify the spatial covariance error structure in occurrence that was not accounted for by the environmental variables; and (3) to synthesize our results with previous findings to make inference on the spatial attributes of the invasion process. Natural plant communities surrounded by areas with high human activity and low forest cover were at highest risk of M. vimineum invasion. The probability of M. vimineum presence also increased with increasing native species richness and soil pH, and decreasing basal area of ericaceous shrubs. After accounting for environmental covariates, evaluation of the spatial covariance error structure revealed that M. vimineum is invading the landscape by a hierarchical process. Infrequent long-distance dispersal events result in new nascent sub-populations that then spread via intermediate- and short-distance dispersal, resulting in 3-km spatial aggregation pattern of sub-populations. Containment or minimisation of its impact on native plant communities will be contingent on understanding how M. vimineum can be prevented from colonizing new suitable habitats. The hierarchical invasion process proposed here provides a framework to organise and focus research and management efforts.     

Hiding in a crowd—does diversity facilitate persistence of a low-quality fungal partner in the mycorrhizal symbiosis?

Given that arbuscular mycorrhizal (AM) fungi are not consistently beneficial to their host plants, it is difficult to explain the evolutionary persistence of this relationship. We tested the hypothesis that increasing either fungal or host biodiversity allows an AM fungus to persist on a host where it shows little benefit. We found that growing such a fungus (an isolate of Glomus custos associating with Plantago laceolata) in combination with certain fungi improved its success as measured by mtLSU DNA abundance. Increasing plant species richness facilitated the spread of this fungus as measured by spore density and fungal colonization; the role of host species richness was not as clear when looking at measures of root abundance. These results indicate that diversity in the AM symbiosis, both plant and fungal, can promote the persistence of low-quality fungi. By existing within a complex mycelial network fungal strains that show little growth benefit to their hosts have a better chance of persisting on that same host. This has the potential to promote selection for heterogeneous AM fungal communities on a small spatial scale.     

Species richness patterns of obligate subterranean beetles (Insecta: Coleoptera) in a global biodiversity hotspot – effect of scale and sampling intensity

We studied species richness patterns of obligate subterranean (troglobiotic) beetles in the Dinaric karst of the western Balkans, using five grid sizes with cells of 80 × 80, 40 × 40, 20 × 20, 10 × 10, and 5 × 5 km. The same two hotspots could be recognized at all scales, although details differed. Differences in sampling intensity were not sufficient to explain these patterns. Correlations between number of species and number of sampled localities increased with increasing cell size. Additional species are expected to be found in the region, as indicated by jackknife 1, jackknife 2, Chao2, bootstrap, and incidence‐based coverage (ICE) species richness estimators. All estimates increased with increasing cell size, except Chao2, with the lowest prediction at the intermediate 20 × 20 km cell size. Jackknife 2 and ICE gave highest estimates and jackknife 1 and bootstrap the lowest. Jackknife 1 and bootstrap estimates changed least with cell size, while the number of single cell species increased. In the highly endemic subterranean fauna with many rare species, bootstrap may be most appropriate to consider. Positive autocorrelation of species numbers was highest at 20 × 20 km scale, so we used this cell size for further analyses. At this scale we added 137 localities with less positional accuracy to 1572 previously considered, and increased 254 troglobiotic species considered to 276. Previously discovered hotspots and their positions did not change, except for a new species‐rich cell which appeared in the south‐eastern region. There are two centres of troglobiotic species richness in the Dinaric karst. The one in the north‐west exhibited high species richness of Trechinae (Carabidae), while in the south‐east, the Leptodirinae (Cholevidae) were much more diverse. These centres of species richness should serve as the starting point for establishing a conservation network of important subterranean areas in Dinaric karst.