Scaling distributional patterns of butterflies across multiple scales: Impact of range history and habitat type

Aim

Assessing the threat status of declining but yet widespread species poses a challenge to applied ecologists. Previous studies using a common metric to describe the spatial aggregation of occurrences across multiple scales, the fractal dimension D_ij, have suggested that species’ distributional trends may be deduced from readily understandable spatial patterns: Expanding species are expected to show more aggregated spatial distributions (higher value of D_ij) than declining species (lower value of D_ij). Here, we revisited these predictions using a large‐scale empirical dataset on Finnish butterflies.

Location

Finland.

Methods

For each butterfly species (n = 97) and across three spatial scales (grid squares of 10 km, 50 km and 100 km), we calculated the area of occupancy (AOO_i) as the sum of occupied grid squares. We employed values of AOO_i to derive the D_ij for each butterfly species. We then used these metrics to compare the changes in spatial patterns of distribution (?AOO_i and ?D_ij) between two time periods, 2000–2002 and 2009–2011.

Results

Majority of the studied butterfly species showed declining areas of occupancy (at the scale of 10 km, ?AOO₁₀) and fractal dimensions (across the scales from 10 km to 100 km, ?D_10–100) between the two study periods. In contrast to predictions, AOO₁₀ and D_10–100 showed negative impacts on the ?AOO₁₀, an observation that may be explained by the high proportion of declining species in our data. Butterfly species with the greatest fractal dimensions at regional scales (D_10–100) in the years 2000–2002 showed both positive long‐term distributional trends and most notable northern recent range limit shifts.

Main conclusions

Our results were in most cases congruent with the prediction of higher fractal dimension values in expanding compared to declining species. As a novel observation, many butterflies expanded northwards in spite of their occurrences getting simultaneously more scattered, particularly in southern Finland.

     

Extrapolating multi‐decadal plant community changes based on medium‐term experiments can be risky: evidence from high‐latitude tundra

For most experimental studies the short‐term responses to manipulation often differ from the long‐term changes in the community composition, dynamics or functioning. Such discrepancy limits the translation of experimental results into key ecological topics such as global environmental change. Here we analyzed plant community dynamics from a 23‐year transplant experiment in the Fennoscandian mountain tundra and explored how well the pattern of responses over the first 12 years of the experiment can predict longer‐term changes. Sod‐blocks of tundra heath vegetation were transplanted to a snowbed 150 m higher in elevation from their origin, where, with contrasting levels of soil wetness, half of the transplants were protected from mammalian herbivores. Throughout the experiment, community changes strongly depended on both plant functional types and experimental treatments. The first 12 years were characterized by a response to transplantation to the snowbed showing a strong increase of graminoid and a decrease of shrub abundances in the transplants. In the longer term, the community divergence increased in particular in response to grazing and soil wetness within the snowbed, while graminoid dominance disappeared. Markov chain models captured the main trends during the first 12 years but they failed to predict their relative abundance after 23 years. In particular, the late dominance of bryophytes in the wet snowbed, the recovery of shrubs in the dry exclosures, and the subordinate status of graminoids deviated from the extrapolation based on the medium‐term trends. Despite clear community dynamical trajectories detected in the first decade, the differences in the temporal scale of both treatment effects and plant functional type responses limited their ability to extrapolate longer‐term trajectories. We find that increasing focus on long‐term experiments is a crucial step to understanding the processes involved in the response of plant communities to global environmental change.     

Cryopreservation of the Norway spruce tissue culture line able to produce extracellular lignin

Somatic hybridization has been used in potato to overcome the sexual barriers between the cultivated (Solanum tuberosum L.) and wild species. To date hundreds of inter/intra-specific somatic hybrids have been produced via protoplast fusions using 23 Solanum species and characterized for multiple traits such as agronomic, disease/pest resistance, salinity, frost and others. With increasing success in recovery of fusion products, somatic hybrids have been exploited in potato genetics, breeding and genomics studies. Here, we report on progress in somatic hybridization research in potato during the past 40 years.     

Phylogeography and population history of the least weasel (Mustela nivalis) in the Palearctic based on multilocus analysis

The least weasel (Mustela nivalis) is one of the most widely distributed carnivorans. While previous studies have identified distinct western and eastern mitochondrial DNA (mtDNA) lineages of the species in the western Palearctic, their broader distributions across the Palearctic have remained unknown. To address the broad-scale phylogeographical structure, we expanded the sampling to populations in Eastern Europe, the Urals, the Russian Far East, and Japan, and analyzed the mtDNA control region and cytochrome b, the final intron of the zinc finger protein on Y chromosome (ZFY), and the autosomal agouti signaling protein gene (ASIP). The mtDNA data analysis exposed the previous western lineage (Clade I) but poorly supported assemblage extending across Palearctic, whereas the previous eastern lineage (Clade II) was reconfirmed and limited in the south western part of the Palearctic. The ZFY phylogeny showed a distinctive split that corresponding to the mtDNA lineage split, although less phylogeographical structure was seen in the ASIP variation. Our data concur with the previous inference of the Black Sea–Caspian Sea area having an ancestral character. The Urals region harbored high mitochondrial diversity, with an estimated coalescent time of around 100,000 years, suggesting this could have been a cryptic refugium. Based on the coalescent-based demographic reconstructions, the expansion of Clade I across the Palearctic was remarkably rapid, while Clade II was relatively stable for a longer time. It seems that Clade II has maintained a constant population size in the temperate region, and the expansive Clade I represents adaptation to the cold regions.     

Synthesis of a tetravalent sialyl Lewis x glycan, a high-affinity inhibitor of L-selectin-mediated lymphocyte binding to endothelium

Kidney transplant rejection is an inflammatory process characterizedby lymphocyte infiltration. Our earlier observations have shownthat peritubular capillary endothelium (PTCE) is the site oflymphocyte entry into the rejecting renal allograft. Duringrejection, PTCE begins to express sialyl Lewis x de novo, andbinds lymphocytes by a mechanism largely dependent on L-selectin.Hence, inhibiting the lymphocyte-endothelial interaction witholigosaccharide ligands of L-selectin offers an attractive possibilityto prevent the inflammation and rejection. Here, we report enzyme-assistedsynthesis of N-acetyllactosamine-based tetra-, deca-, and docosamericsaccharides carrying one, two or four distally located sialylLewis x groups [Neu-NAc     

Five subspecies of the Dorogostaiskia parasitica complex (Dybowsky) (Crustacea: Amphipoda: Acanthogammaridae), epibionts of sponges in Lake Baikal

Based on morphological and molecular characters, the gammaroid amphipod Dorogostaiskia parasitica, living as an epibiont on sponges in Lake Baikal, Siberia, is here split into five parapatrically or allopatrically distributed subspecies: D. p. parasitica (Dybowsky, Horae Societatis Entomologicae Rossicae 10(Beiheft):1–218, 1874), D. p. kamaltynovi subsp. nov., D. p. hanajevi subsp. nov., D. p. ushkaniensis subsp. nov., and D. p. stenocephala subsp. nov. Diagnostic differences are described in the shape of dorsal keels, shape of head, length of antenna 1, number of segments of accessory flagellum, shape and armature of coxal plates, relative lengths of pereopod segments, and body coloration. Each subspecies is characterized by a distinct mitochondrial lineage, differing from others by 5–11% in the sequence of the COI gene, while they do not differ in nuclear 28S rRNA gene sequence. The question of taxonomic ranks for members of intralacustrine species complexes is considered and an argument is presented for a use of the subspecies rank for parapatrically distributed population segments that are distinguished by multiple independent geographically congruent character differences. This usage sorts out a pattern of systematic diversity lower than one based on documented reproductive isolation (e.g., sympatry) of full species but stronger than that based on single-gene genealogies alone.     

Functional–structural plant models: a growing paradigm for plant studies

A number of research groups in various areas of plant biology as well as computer science and applied mathematics have addressed modelling the spatiotemporal dynamics of growth and development of plants. This has resulted in development of functional–structural plant models (FSPMs). In FSPMs, the plant structure is always explicitly represented in terms of a network of elementary units. In this respect, FSPMs are different from more abstract models in which a simplified representation of the plant structure is frequently used (e.g. spatial density of leaves, total biomass, etc.). This key feature makes it possible to build modular models and creates avenues for efficient exchange of model components and experimental data. They are being used to deal with the complex 3-D structure of plants and to simulate growth and development occurring at spatial scales from cells to forest areas, and temporal scales from seconds to decades and many plant generations. The plant types studied also cover a broad spectrum, from algae to trees. This special issue of Annals of Botany features selected papers on FSPM topics such as models of morphological development, models of physical and biological processes, integrated models predicting dynamics of plants and plant communities, modelling platforms, methods for acquiring the 3-D structures of plants using automated measurements, and practical applications for agronomic purposes.