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Woody plant encroachment affects dry grasslands globally. To predict changes in biodiversity and ecosystem processes, it is important to understand how this process affects the functional composition of grassland organism groups. In this context, seminatural wooded meadows represent a form of experimental manipulation—where open grassland and woody patches co-occur in homogeneous environmental conditions due to human management decisions—which provides an opportunity to address the effect of woody plant encroachment on vegetation and soil biota. We used environmental DNA metabarcoding to address variation in plant, soil fungal, and soil animal communities in parallel. We also addressed functional groups of fungi—animal and plant pathogens, saprotrophs, decomposers, arbuscular mycorrhizal, ectomycorrhizal, endophytic, and other symbiotrophic fungi—and of soil animals—fungivores, bacterivores, litter feeders, root feeders, macro plant feeders, algal/lichen feeders, predators, and parasites. Co-variation between communities was detected from aboveground vegetation plots and metabarcoding of soil DNA, in terms of estimated richness and compositional patterns. Differences between open and wooded patches were most pronounced among plants and symbiotic fungi, whereas soil animals exhibited less marked differences. For most organisms, mean richness, as well as total richness per habitat type, was higher in open than wooded patches, but ectomycorrhizal fungi exhibited the opposite pattern. The functional structure of the soil biotic community, as characterized by the proportion of DNA sequences attributed to different functional groups, differed significantly between open and wooded grassland patches, with symbiotic fungi (arbuscular mycorrhizal, ectomycorrhizal, and other symbiotrophic [mostly orchid mycorrhizal] fungi) contributing most to the difference. This study supports the notion that a soil DNA-based metabarcoding approach can provide insights into the diversity and composition of multiple taxonomic groups in natural ecosystems. It also provides a first demonstration of the complex changes to the functional structure of the belowground community that accompany woody plant encroachment in grasslands. This research was supported by the University of Tartu (PLTOM20903) and the European Regional Development Fund (Centre of Excellence EcolChange).

Climate change has a great impact on boreal ecosystems including Siberian larch forests. As a consequence of warming, larch grow is possible in areas where climate used to be too cold, leading to a shift of the tree line into more arctic regions. Most plants co-exist in symbiosis with heterotrophic organisms surrounding their root system. In arctic ecosystems, mycorrhizal fungi are a prerequisite for plant establishment and survival because they support nutrient uptake from nutrient-poor soils and maintain the water supply. Until now, however, knowledge about the co-variation of vegetation and fungi is poor. Certainly, the understanding of dynamic changes in biotic interactions is important to understand adaptation mechanisms of ecosystems to climate change.We investigated sedimentary ancient DNA from Lake Levinson Lessing, Taymyr Peninsula (Arctic Siberia, tundra), Lake Lama, Lake Kyutyunda (both northern Siberia, tundra-taiga transition zone) and Lake Bolshoe Toko (southern Siberia, forest area) covering the last about 45.000 years using ITS primers for fungi along with the chloroplast P6 loop marker for vegetation metabarcoding. We found changes in the fungal communities that are in broad agreement with vegetation turnover. To our knowledge, this is the first broad ecological study on lake sediment cores to analyze fungal biodiversity in relation to vegetation change on millennial time scales.

Males of socially monogamous species can increase their siring success via within-pair and extra-pair fertilizations. In this study, we focused on the different sources of (co)variation between these siring routes, and asked how each contributes to total siring success. We quantified the fertilization routes to siring success, as well as behaviors that have been hypothesized to affect siring success, over a five-year period for a wild population of great tits Parus major. We considered siring success and its fertilization routes as "interactive phenotypes" arising from phenotypic contributions of both members of the social pair. We show that siring success is strongly affected by the fecundity of the social (female) partner. We also demonstrate that a strong positive correlation between extra-pair fertilization success and paternity loss likely constrains the evolution of these two routes. Moreover, we show that more explorative and aggressive males had less extra-pair fertilizations, whereas more explorative females laid larger clutches. This study thus demonstrates that (co)variation in siring routes is caused by multiple factors not necessarily related to characteristics of males. We thereby highlight the importance of acknowledging the multilevel structure of male fertilization routes when studying the evolution of male mating strategies.

Animal communication among competitors often relies on honest signaling such that displays of aggression accurately reflect an individual’s performance abilities. Moreover, the maintenance of honest signaling should be enhanced by the existence of consistent individual differences in behavior and performance, and individual-level correlations between them. Despite this, researchers studying honest signaling rarely measure behavioral repeatability. Here, we demonstrate that field behaviors of free-ranging lizards and a measure of locomotor performance in the laboratory are consistent among individuals (i.e. they were repeatable), although the magnitude of repeatability varies among traits. In addition, endurance appears to be correlated with display frequency in the field at the individual level, suggesting that display frequency is an honest signal of endurance. Interestingly, this correlation was strong for males, and non-existent for females. Our results extend previous studies of behavior‐performance relationships by identifying a sex-specific correlation between traits and by partitioning phenotypic correlations into between- and within-individual components. This analytical approach is emerging as a powerful tool for studying individual variation in behavior and physiology.

Repeatability is an important concept in evolutionary analyses because it provides information regarding the benefit of repeated measurements and, in most cases, a putative upper limit to heritability estimates. Repeatability (R) of different aspects of energy metabolism and behavior has been demonstrated in a variety of organisms over short and long time intervals. Recent research suggests that consistent individual differences in behavior and energy metabolism might covary. Here we present new data on the repeatability of body mass, standard metabolic rate (SMR), voluntary exploratory behavior, and feeding rate in a semiaquatic salamander and ask whether individual variation in behavioral traits is correlated with individual variation in metabolism on a whole-animal basis and after conditioning on body mass. All measured traits were repeatable, but the repeatability estimates ranged from very high for body mass (R = 0.98), to intermediate for SMR (R = 0.39) and food intake (R = 0.58), to low for exploratory behavior (R = 0.25). Moreover, repeatability estimates for all traits except body mass declined over time (i.e., from 3 to 9 wk), although this pattern could be a consequence of the relatively low sample size used in this study. Despite significant repeatability in all traits, we find little evidence that behaviors are correlated with SMR at the phenotypic and among-individual levels when conditioned on body mass. Specifically, the phenotypic correlations between SMR and exploratory behavior were negative in all trials but significantly so in one trial only. Salamanders in this study showed individual variation in how their exploratory behavior changed across trials (but not body mass, SMR, and feed intake), which might have contributed to observed changing correlations across trials.

Summary 1. Standard metabolic rate (SMR) and maximal metabolic rate (MMR) are fundamental measures in ecology and evolution because they set the scope within which animals can perform activities that directly affect fitness. In ectotherms, both SMR and MMR are repeatable over time when measured at a single ambient temperature (Ta). 2. Many ectotherms encounter variable Ta from day to day and over their lifetime, yet it is currently unknown whether individual differences hold across an ecologically relevant range of Ta (i.e. thermal repeatability; RT). Moreover, it is possible that thermal sensitivity of SMR and MMR are important individual attributes, and correlated with one another, but virtually nothing is known about this at present. 3. We measured SMR and MMR across an ecologically relevant Ta gradient (i.e. from 10 to 25 °C) in wild-caught salamanders (Plethodon albagula) and found that RT was significant in both traits. SMR and MMR were also positively correlated, resulting in a lower RT in absolute and factorial aerobic scopes (AAS and FAS). 4. We found significant individual differences in thermal sensitivity for both SMR and MMR, but not for AAS and FAS. The intercept (at Ta =0 °C) and the slope of the thermal reaction norms were negatively correlated; individuals with low MR at low Ta had a higher thermal sensitivity. Finally, individuals with a high thermal sensitivity for SMR also had high thermal sensitivity for MMR. 5. Our results suggest that natural selection occurring over variable Ta may efficiently target the overall level of – and thermal sensitivity in – SMR and MMR. However, this may not be the case for metabolic scopes, as the positive correlation between SMR and MMR, in addition to their combined changes in response to Ta, yielded little individual variation in AAS and FAS. 6. Our results support the idea that organisms with low metabolism at low Ta have a high metabolic thermal sensitivity as a compensatory mechanism to benefit in periods of warmer environmental conditions. Hence, our study reveals the importance of considering within-individual variation in metabolism, as it may represent additional sources of adaptive (co)variation.

The adaptive benefits of extended phenotypic plasticity are imprecisely defined due to a paucity of experiments examining traits that are manipulable and measurable across environments. Spider webs are often used as models to explore the adaptive benefits of variations in extended phenotypes across environments. Nonetheless, our understanding of the adaptive nature of the plastic responses of spider webs is impeded when web architectures and silk physicochemical properties appear to co-vary. An opportunity to examine this co-variation is presented by modifying prey items while measuring web architectures and silk physiochemical properties. Here we performed two experiments to assess the nature of the association between web architectures and gluey silk properties when the orb web spider Argiope keyserlingi was fed a diet that varied in either mass and energy or prey size and feeding frequency. We found web architectures and gluey silk physicochemical properties to co-vary across treatments in both experiments. Specifically, web capture area co-varied with gluey droplet morphometrics, thread stickiness and salt concentrations when prey mass and energy were manipulated, and spiral spacing co-varied with gluey silk salt concentrations when prey size and feeding frequency were manipulated. We explained our results as A. keyserlingi plastically shifting its foraging strategy as multiple prey parameters simultaneously varied. We confirmed and extended previous work by showing that spiders use a variety of prey cues to concurrently adjust web and silk traits across different feeding regimes.

Relationships between species diversity and genetic diversity, the two most important elements of biodiversity, have recently attracted considerable interest in the field of community genetics. The present study contributes to this issue by addressing three questions that seem to have been ignored so far, namely whether the use of (a) different diversity measures, of (b) different components of diversity, and of (c) different genetic traits may lead to different assessements of speciesgenetic diversity relationships. For this purpose, data on species composition and genetic traits were collected from the natural regeneration of nine forest communities, which consist of three pure and six mixed tree stands located in the Thuringian forest area. The genetic traits comprised one DNA (AFLP) and five isozyme traits all of which were determined in all species. In contrast to other studies, the species diversity was determined for two components, SD (species diversity) and NeS (effective number of genetically distinct species), and the genetic diversity was determined for three components, TSGD (the transspecific genetic diversity taken over all species of a community), ISGD and NGS (each describing a special average of intraspecific genetic diversity). Each component was quantified by measures of diversity representing four orders of the Renyi/Hillfamily. The orders correspond to the degree to which prevalence of types is considered in the diversity measure (at the lowest order, known as richness, prevalence is disregarded, with increasing order, the diversity measure reports prevalent types only). In our data, the diversity measured for each genetic trait separately showed a great range of variation across traits and components of diversity even in the same stand. The choice of the diversity component thus turned out to have a substantial effect on the assessment of the level of genetic diversity within stands. This prompted more detailed studies of the relationships between species and genetic diversity. Relationships were quantified with the help of the coefficient of co-variation, and the statistical significance of the co-variations was verified through permutation tests. The co-variations between SD and TSGD were found to be generally positive and in most cases significant, but the co-variation declined with increasing orders of diversity for most of the genetic traits. In contrast, the co-variation between SD and ISGD was not consistent for the four orders of diversity. In particular, the co-variations for the highest order were found to be negative for all traits. The results of our explorative study thus demonstrate that the assessment of levels of genetic diversity within stands as well as species-genetic interrelations critically depend on the choice of the diversity component, of the order of diversity, and of the genetic trait. These observations lend support to different and even opposing hypotheses on the processes potentially generating species-genetic relationships. Therefore, strategies in the conservation of biodiversity, for example, are suggested to be related more specifically to the components and orders of diversity to be safegarded and to consider the functions of genetic traits in relation to adaptationally relevant environmental factors.

Computerized ecological momentary assessment (EMA) is widely accepted as a “gold standard” method for capturing momentary symptoms repeatedly experienced in daily life. Although many studies have addressed the within-individual temporal variations in momentary symptoms compared with simultaneously measured external criteria, their concurrent associations, specifically with continuous physiological measures, have not been rigorously examined. Therefore, in the present study, we first examined the variations in momentary symptoms by validating the associations among self-reported symptoms measured simultaneously (depressive mood, anxious mood, and fatigue) and then investigated covariant properties between the symptoms (especially, depressive mood) and local statistics of locomotor activity as the external objective criteria obtained continuously. Healthy subjects (N = 85) from three different populations (adolescents, undergraduates, and office workers) wore a watch-type computer device equipped with EMA software for recording the momentary symptoms experienced by the subjects. Locomotor activity data were also continuously obtained by using an actigraph built into the device. Multilevel modeling analysis confirmed convergent associations by showing positive correlations among momentary symptoms. The increased intermittency of locomotor activity, characterized by a combination of reduced activity with occasional bursts, appeared concurrently with the worsening of depressive mood. Further, this association remained statistically unchanged across groups regardless of group differences in age, lifestyle, and occupation. These results indicate that the temporal variations in the momentary symptoms are not random but reflect the underlying changes in psychophysiological variables in daily life. In addition, our findings on the concurrent changes in depressive mood and locomotor activity may contribute to the continuous estimation of changes in depressive mood and early detection of depressive disorders.

Lice (Insecta: Phthiraptera) are ectoparasites that reduce host life expectancy and sexual attractiveness. Their taxonomic richness varies considerably among their hosts. Previous studies have already explored some important factors shaping louse diversity. An unexplored potential correlate of louse taxonomic richness is host behavioural flexibility. In this comparative study, we examine the relationship between louse generic richness, innovative capabilities (as a proxy for behavioural flexibility), and brain size while controlling for host species diversity, phylogeny, body size and research effort. Using data for 108 avian families, we found a highly significant positive relationship between host innovative capabilities and the taxonomic richness of amblyceran lice, but a lack of a similar relationship in ischnoceran lice. Host brain size had only a marginal impact on amblyceran diversity and no correlation with ischnoceran diversity. This suggests that the effect in Amblycera is not mediated by metabolic limitations due to the energetic costs of brain size and maintenance, rather directly caused by the ecological differences between hosts with differing cognitive capabilities. We propose four alternative and mutually non-exclusive hypotheses that may explain this phenomenon.