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opencc-zeroDec 2013View details →

Data from: Fine-scale spatial genetic dynamics over the life-cycle of the tropical tree Prunus africana

Studying fine-scale spatial genetic patterns across life stages is a powerful approach to identify ecological processes acting within tree populations. We investigated spatial genetic dynamics across five life stages in the insect-pollinated and vertebrate-dispersed tropical tree Prunus africana in Kakamega Forest, Kenya. Using six highly polymorphic microsatellite loci, we assessed genetic diversity and spatial genetic structure (SGS) from seed rain and seedlings, and different sapling stages to adult trees. We found significant SGS in all stages, potentially caused by limited seed dispersal and high recruitment rates in areas with high light availability. SGS decreased from seed and early seedling stages to older juvenile stages. Interestingly, SGS was stronger in adults than in late juveniles. The initial decrease in SGS was probably driven by both random and non-random thinning of offspring clusters during recruitment. Intergenerational variation in SGS could have been driven by variation in gene flow processes, overlapping generations in the adult stage or local selection. Our study shows that complex sequential processes during recruitment contribute to SGS of tree populations.

Data from: Life-history characteristics and landscape attributes as drivers of genetic variation, gene flow and fine-scale population structure in Northern Dolly Varden (Salvelinus malma malma) in Canada

The Northern Dolly Varden (Salvelinus malma malma) displays variable life-history types and occupies freshwater habitats with varying levels of connectivity. Here, we assayed microsatellite DNA variation in Northern Dolly Varden from the western Canadian Arctic to resolve landscape and life history variables driving variation in genetic diversity and population structure. Overall, genetic variation was highest in anadromous populations and lowest in those isolated above waterfalls with stream-resident forms intermediate between the two. Anadromous and isolated populations were genetically divergent from each other while no genetic differentiation was detectable between sympatric anadromous and stream-resident forms. Population structure was stable over 25 years, hierarchically organized and conformed to an isolation-by-distance pattern, but stream-isolated forms often deviated from these patterns. Gene flow occurred primarily among Yukon North Slope populations and between sympatric anadromous and resident forms. These results were sex-dependent to some extent, but were influenced more by reproductive status and life history. Our study provides novel insights into the life history, population demographic and habitat variables that shape the distribution of genetic variation and population structure in Arctic fluvial habitats while providing a spatial context for management and conservation.

Data from: The scale-of-choice effect and how estimates of assortative mating in the wild can be biased due to heterogeneous samples

The mode in which sexual organisms choose mates is a key evolutionary process, as it can have a profound impact on fitness and speciation. One way to study mate choice in the wild is by measuring trait correlation between mates. Positive assortative mating is inferred when individuals of a mating pair display traits that are more similar than those expected under random mating while negative assortative mating is the opposite. A recent review of 1134 trait correlations found that positive estimates of assortative mating were more frequent and larger in magnitude than negative estimates. Here we describe the scale-of-choice effect (SCE), which occurs when mate choice exists at a smaller scale than that of the investigator's sampling, while simultaneously the trait is heterogeneously distributed at the true scale-of-choice. We demonstrate the SCE by Monte Carlo simulations and estimate it in two organisms showing positive (Littorina saxatilis) and negative (L. fabalis) assortative mating. Our results show that both positive and negative estimates are biased by the SCE by different magnitudes, typically towards positive values. Therefore, the low frequency of negative assortative mating observed in the literature may be due to the SCE's impact on correlation estimates, which demands new experimental evaluation.

opencc-zeroDec 2012View details →

Data from: A novel multi-scale assessment of community assembly across time, space, and functional niche

A basic ecological tenet is that organisms in a community occupy different niches and have different traits, but how consistently competition, selection, and phylogenetic effects structure communities remains uncertain. Are all communities created equal? We examine how mammalian carnivoran communities are assembled with regard to mass, diet, and locomotion. Here, we use a multivariate nearest-neighbor framework to examine multiple North American localities spanning 3 million years to determine whether community assembly is consistent through time and four modern localities around the world to assess the effects of habitat. Additionally, we examined how trait patterns differ among families and how family-level evolutionary effects affect them. We found some broadly consistent patterns, although differences are more pronounced than similarities. Diet is more affected by evolutionary constraints than by time or place. Locomotion is most affected by habitat, and the ability to partition niches is related to habitat heterogeneity. Mass is influenced by family, but also by habitat and the mass-selective extinction events at the end-Pleistocene. These findings indicate that assembly patterns are not largely determined by within-community interactions but instead show that each community is a product of its independent variables.

Data from: Variation in the ecstatic display call of the Gentoo Penguin (Pygoscelis papua) across regional geographic scales

Geographic variation in bird vocalizations is common and has been associated with genetic differences and speciation, as well as with short-term changes in response to anthropogenic noise. Because vocalizations are used for individual recognition in many species, geographic variation in these traits may affect mate choice, pair bonding, and territory defense. Anecdotal evidence suggests the existence of geographic variation in vocalizations between isolated populations of Gentoo Penguins (Pygoscelis papua), but there have been no comprehensive studies of Gentoo Penguin vocalizations across a broad geographic range. We used acoustic recordings of ambient colony sound at 22 breeding colonies in the Antarctic Peninsula and South Shetland Islands, South Georgia, the Falkland Islands, and Argentina to address 2 main questions regarding Gentoo Penguin vocalizations: (1) How do ecstatic display calls vary both within and between individuals, colonies, and regions? (2) Can ecstatic display calls be used to distinguish subspecies? We found high levels of variation between individuals and between colonies, but little additional variation between regions or subspecies. We found no trends to suggest a latitudinal gradient in vocal characteristics, although we did find that some measures varied with relative distance between colonies. Although we found significant differences at the colony level, unknown calls could not easily be categorized to colony or region by machine learning. We conclude that the vocal soundscape of each colony is driven by variation between individuals within a colony and, developing independently from neighboring colonies, becomes differentiated from other colonies through a process of drift. Although individual calls could, in most cases, be identified to subspecies by machine learning, our analysis suggests that subspecies differences may be driven by variation among colonies and that subspecies identification may be unreliable using acoustics alone.

opencc-zeroDec 2013View details →

Data from: Automated DNA-based plant identification for large-scale biodiversity assessment

Rapid degradation of tropical forests urges to improve our efficiency in large-scale biodiversity assessment. DNA-barcoding can assist greatly in this task, but commonly used phenetic approaches for DNA-based identifications rely on the existence of comprehensive reference databases, which are infeasible for hyperdiverse tropical ecosystems. Alternatively, phylogenetic methods are more robust to sparse taxon sampling but time-consuming, while multiple alignment of species-diagnostic, typically length-variable markers can be problematic across divergent taxa. We advocate the combination of phylogenetic and phenetic methods for taxonomic assignment of DNA-barcode sequences against incomplete reference databases such as GenBank, and we developed a pipeline to implement this approach on large-scale plant diversity projects. The pipeline workflow includes several steps: database construction and curation, query sequence clustering, sequence retrieval, distance calculation, multiple alignment and phylogenetic reconstruction. We describe the strategies used to establish these steps and the optimisation of parameters to fit the selected psbA-trnH marker. We tested the pipeline using infertile plant samples and herbivore diet sequences from the highly threatened Nicaraguan seasonally dry forest and exploiting a valuable purpose-built resource: a partial local reference database of plant psbA-trnH. The selected methodology proved efficient and reliable for high-throughput taxonomic assignment, and our results corroborate the advantage of applying 'strict' tree-based criteria to avoid false positives. The pipeline tools are distributed as the scripts suite 'BAGpipe' (pipeline for Biodiversity Assessment using GenBank data), which can be readily adjusted to the purposes of other projects and applied to sequence-based identification for any marker or taxon.

Data from: Termite mounds differ in their importance for herbivores across savanna types, seasons and spatial scales

Herbivores do not forage uniformly across landscapes, but select for patches of higher nutrition and lower predation risk. Macrotermes mounds contain higher concentrations of soil nutrients and support grasses of higher nutritional value than the surrounding savanna matrix, attracting mammalian grazers that preferentially forage on termite mound vegetation. However, little is known about the spatial extent of such termite influence on grazing patterns and how it might differ in time and space. We measured grazing intensity in three African savanna types differing in rainfall and foliar nutrients and predicted that the functional importance of mounds for grazing herbivores would increase as the difference in foliar nutrient levels between mound and savanna matrix grasses increases and the mounds become more attractive. We expected this to occur in nutrient-poor areas and during the dry season when savanna matrix grass nutrient levels are lower. Tuft use and grass N and P content were measured along transects away from termite mounds, enabling calculation of the spatial extent of termite influence on mammalian grazing. Using termite mound densities estimated from airborne light detection and ranging (LiDAR), we further upscaled field-based results to determine the percentage of the landscape influenced by termite activity. Grasses in close proximity to termite mounds were preferentially grazed at all sites and in both seasons, but the strength of mound influence varied between savanna types and seasons. In the wet season, mounds had a relatively larger effect on grazers at the landscape scale in the nutrient-poor, wetter savanna, whereas in the dry season the pattern was reversed with more of the landscape influenced at the nutrient-rich, driest site. Our results reveal that termite mounds enhance the value of savanna landscapes for herbivores, but that their functional importance varies across savanna types and seasons.

Data from: Combined use of GPS and accelerometry reveals fine scale three-dimensional foraging behaviour in the short-tailed shearwater

Determining the foraging behaviour of free-ranging marine animals is fundamental for assessing their habitat use and how they may respond to changes in the environment. However, despite recent advances in bio-logging technology, collecting information on both at-sea movement patterns and activity budgets still remains difficult in small pelagic seabird species due to the constraints of instrument size. The short-tailed shearwater, the most abundant seabird species in Australia (ca 23 million individuals), is a highly pelagic procellariiform. Despite its ecological importance to the region, almost nothing is known about its at-sea behaviour, in particular, its foraging activity. Using a combination of GPS and tri-axial accelerometer data-loggers, the fine scale three-dimensional foraging behaviour of 10 breeding individuals from two colonies was investigated. Five at-sea behaviours were identified: (1) resting on water, (2) flapping flight, (3) gliding flight, (4) foraging (i.e., surface foraging and diving events), and (5) taking-off. There were substantial intra- and inter- individual variations in activity patterns, with individuals spending on average 45.8% (range: 17.1–70.0%) of time at sea resting on water and 18.2% (range: 2.3–49.6%) foraging. Individuals made 76.4 ± 65.3 dives (range: 8–237) per foraging trip (mean duration 9.0 ± 1.9 s), with dives also recorded during night-time. With the continued miniaturisation of recording devices, the use of combined data-loggers could provide us with further insights into the foraging behaviour of small procellariiforms, helping to better understand interactions with their prey.

Data from: RAD sequencing resolves fine-scale population structure in a benthic invertebrate: implications for understanding phenotypic plasticity

The field of molecular ecology is transitioning from the use of small panels of classical genetic markers such as microsatellites to much larger panels of single nucleotide polymorphisms (SNPs) generated by approaches like RAD sequencing. However, few empirical studies have directly compared the ability of these methods to resolve population structure. This could have implications for understanding phenotypic plasticity, as many previous studies of natural populations may have lacked the power to detect genetic differences, especially over micro-geographic scales. We therefore compared the ability of microsatellites and RAD sequencing to resolve fine-scale population structure in a commercially important benthic invertebrate by genotyping great scallops (Pecten maximus) from nine populations around Northern Ireland at 13 microsatellites and 10 539 SNPs. The shells were then subjected to morphometric and colour analysis in order to compare patterns of phenotypic and genetic variation. We found that RAD sequencing was superior at resolving population structure, yielding higher Fst values and support for two distinct genetic clusters, whereas only one cluster could be detected in a Bayesian analysis of the microsatellite dataset. Furthermore, appreciable phenotypic variation was observed in size-independent shell shape and coloration, including among localities that could not be distinguished from one another genetically, providing support for the notion that these traits are phenotypically plastic. Taken together, our results suggest that RAD sequencing is a powerful approach for studying population structure and phenotypic plasticity in natural populations.

opencc-zeroNov 2019View details →

Data from: Hierarchical Hybrid Enrichment: multi-tiered genomic data collection across evolutionary scales, with application to chorus frogs (Pseudacris)

Determining the optimal targets of genomic sub-sampling for phylogenomics, phylogeography, and population genomics remains a challenge for evolutionary biologists. Of the available methods for sub-sampling the genome, hybrid enrichment (sequence capture) has become one of the primary means of data collection for systematics, due to the flexibility and cost efficiency of this approach. Despite the utility of this method, information is lacking as to what genomic targets are most appropriate for addressing questions at different evolutionary scales. In this study, first we compare the benefits of target loci developed for deep- and shallow-scales by comparing these loci at each of three taxonomic levels: within a genus (phylogenetics), within a species (phylogeography) and within a hybrid zone (population genomics). Specifically, we target evolutionary conserved loci that are appropriate for deep phylogenetic scales and more rapidly evolving loci that are informative for phylogeographic and population genomic scales. Second, we assess the efficacy of targeting multiple locus sets for different taxonomic levels in the same hybrid enrichment reaction, an approach we term hierarchical hybrid enrichment. Third, we apply this approach to the North American chorus frog genus Pseudacris to answer longstanding evolutionary questions across taxonomic and temporal scales. We demonstrate that in this system the type of genomic target that produces the most resolved gene trees differs depending on the taxonomic level, although the potential for error is substantially lower for the deep-scale loci at all levels. We successfully recover data for the two different locus sets with high efficiency. Using hierarchical data targeting deep and shallow levels, we (a) resolve the phylogeny of the genus Pseudacris and introduce a novel visual and hypothesis-testing method that uses nodal heat maps to examine the robustness of branch support values to the removal of sites and loci; (b) estimate the phylogeographic history of P. feriarum, which reveals five independent invasions of sympatry by this species to form replicated reinforcement contact zones with P. nigrita with ongoing gene flow into sympatry; and (c) quantify with high confidence the frequency of hybridization in one of these zones between P. feriarum and P. nigrita, which is much lower than previously found by microsatellite-based studies. We find that the hierarchical hybrid enrichment approach offers an efficient, multi-tiered data collection method for simultaneously addressing questions spanning multiple evolutionary scales.

opencc-zeroSep 2019View details →

Data from: Integrated genome-scale analysis identifies novel genes and networks underlying senescence in maize

Premature senescence in annual crops reduces yield while delayed senescence, termed stay-green, is known to impose both positive and negative impact on yield and nutrition quality. Despite the importance, scant information is available on the genetic architecture of senescence in maize (Zea mays L.) and other cereals. We combined a systematic characterization of natural diversity for senescence in maize and co-expression networks derived from transcriptome analysis of normally senescing and stay-green lines. Sixty-four candidate genes were identified by GWAS, and 14 of these are supported by additional evidence for involvement in senescence-related processes including proteolysis, sugar transport and signaling, and sink activity. Eight of the GWAS candidates, independently supported by a co-expression network underlying stay-green, include a trehalose-6-phosphate synthase, a NAC transcription factor, and two xylan biosynthetic enzymes. Source-sink communication and the activity of cell walls as a secondary sink emerge as key determinants of stay-green. Mutant analysis supports the role of a candidate encoding cysteine protease in stay-green in Arabidopsis (Arabidopsis thaliana), and analysis of natural alleles suggest a similar role in maize. This study provides a foundation for enhanced understanding and manipulation of senescence for increasing carbon yield, nutritional quality, and stress tolerance of maize and other cereals.

Data from: Incorporating interspecific competition into species-distribution mapping by upward scaling of small-scale model projections to the landscape

There are a number of overarching questions and debate in the scientific community concerning the importance of biotic interactions in species distribution models at large spatial scales. In this paper, we present a framework for revising the potential distribution of tree species native to the Western Ecoregion of Nova Scotia, Canada, by integrating the long-term effects of interspecific competition into an existing abiotic-factor-based definition of potential species distribution (PSD). The PSD model is developed by combining spatially explicit data of individualistic species' response to normalized incident photosynthetically active radiation, soil water content, and growing degree days. A revised PSD model adds biomass output simulated over a 100-year timeframe with a robust forest gap model and scaled up to the landscape using a forestland classification technique. To demonstrate the method, we applied the calculation to the natural range of 16 target tree species as found in 1,240 provincial forest-inventory plots. The revised PSD model, with the long-term effects of interspecific competition accounted for, predicted that eastern hemlock (Tsuga canadensis), American beech (Fagus grandifolia), white birch (Betula papyrifera), red oak (Quercus rubra), sugar maple (Acer saccharum), and trembling aspen (Populus tremuloides) would experience a significant decline in their original distribution compared with balsam fir (Abies balsamea), black spruce (Picea mariana), red spruce (Picea rubens), red maple (Acer rubrum L.), and yellow birch (Betula alleghaniensis). True model accuracy improved from 64.2% with original PSD evaluations to 81.7% with revised PSD. Kappa statistics slightly increased from 0.26 (fair) to 0.41 (moderate) for original and revised PSDs, respectively.

opencc-zeroDec 2012View details →

Data from: Ecological segregation in a small mammal hybrid zone: habitat-specific mating opportunities and selection against hybrids restrict gene flow on a fine spatial scale

The degree to which closely related species interbreed is determined by a complex interaction of ecological, behavioral, and genetic factors. We examine the degree of interbreeding between two woodrat species, Neotoma bryanti and N. lepida, at a sharp ecological transition. We identify the ecological association of each genotypic class, assess the opportunity for mating between these groups, and test whether they have similar patterns of year-to-year persistence on our study site. We find that 13% of individuals have a hybrid signature but that the two parental populations and backcrosses are highly segregated by habitat type and use. Also, we find that adult hybrids are comparable to parental types in terms of year-to-year persistence on our site but that, among juveniles, significantly fewer hybrids reach adulthood on site compared to their purebred counterparts. Our analyses show that this hybrid zone is maintained by occasional nonassortative mating coupled with hybrid fertility, but that these factors are balanced by lower apparent survival of juvenile hybrids and habitat-based preference or selection that limits heterospecific mating while promoting backcrossing to habitat-specific genotypes. This system presents a novel example of the role that sharp resource gradients play in reproductive isolation and the potential for genetic introgression.

opencc-zeroJul 2019View details →

Data from: Multi-scale model of regional population decline in little brown bats due to white-nose syndrome

The introduced fungal pathogen Pseudogymnoascus destructans is causing decline of several species of bats in North America, with some even at risk of extinction or extirpation. The severity of the epidemic of white-nose syndrome caused by P. destructans has prompted investigation of the transmission and virulence of infection at multiple scales, but linking these scales is necessary to quantify the mechanisms of transmission and assess population-scale declines. We build a model connecting within-cave disease dynamics of little brown bats to regional scale dispersal, reproduction, and disease spread, including multiple plausible mechanisms of transmission. We parameterize the model using the approach of plausible parameter sets, by comparing stochastic simulation results to statistical probes from empirical data on within-cave prevalence and survival, as well as between-cave spread across a region. Our results are consistent with frequency-dependent transmission between bats, support an important role of environmental transmission, and show very little effect of dispersal among colonies on metapopulation survival. The model also offers a generalizable method to assess hypotheses about cave-to-cave transmission and to identify gaps in knowledge about key processes, and could be expanded to include additional mechanisms or bat species as research on this detrimental fungus progresses.

Data from: Spatial pattern and scale influence invader demographic response to simulated precipitation change in an annual grassland community

It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requires detailed demographic information. Explicit study of the impact of pattern on demographic response is particularly important for species that are naturally patchy, such as the invasive grass, Aegilops triuncialis. In the northern California Coast Range, where climate change may increase or decrease mean annual rainfall, we conducted a field experiment to understand the interaction of climate change and local-scale patterning on the demography of A. triuncialis. We manipulated precipitation (reduced, ambient, or augmented), seed density, and seeding pattern. Demographic and environmental data were collected for three years following initial seeding. Pattern and scale figure prominently in the demographic response of A. triuncialis to precipitation manipulation. Pattern interacts with precipitation and seeding density in its influence on per-plant seed output. Although per-plot seed production was highest when seeds were not aggregated, per-plant seed output was higher in aggregated patches. Results suggest aggregation of invasive A. triuncialis reduces the detrimental impact of interspecific competition in its invaded community, and that interspecific competition per se has a stronger impact than intraspecific competition

Data from: Spatial structure of above-ground biomass limits accuracy of carbon mapping in rainforest but large scale forest inventories can help to overcome

Precise mapping of above-ground biomass (AGB) is a major challenge for the success of REDD+ processes in tropical rainforest. The usual mapping methods are based on two hypotheses: a large and long-ranged spatial autocorrelation and a strong environment influence at the regional scale. However, there are no studies of the spatial structure of AGB at the landscapes scale to support these assumptions. We studied spatial variation in AGB at various scales using two large forest inventories conducted in French Guiana. The dataset comprised 2507 plots (0.4 to 0.5 ha) of undisturbed rainforest distributed over the whole region. After checking the uncertainties of estimates obtained from these data, we used half of the dataset to develop explicit predictive models including spatial and environmental effects and tested the accuracy of the resulting maps according to their resolution using the rest of the data. Forest inventories provided accurate AGB estimates at the plot scale, for a mean of 325 Mg.ha-1. They revealed high local variability combined with a weak autocorrelation up to distances of no more than10 km. Environmental variables accounted for a minor part of spatial variation. Accuracy of the best model including spatial effects was 90 Mg.ha-1 at plot scale but coarse graining up to 2-km resolution allowed mapping AGB with accuracy lower than 50 Mg.ha-1. Whatever the resolution, no agreement was found with available pan-tropical reference maps at all resolutions. We concluded that the combined weak autocorrelation and weak environmental effect limit AGB maps accuracy in rainforest, and that a trade-off has to be found between spatial resolution and effective accuracy until adequate "wall-to-wall" remote sensing signals provide reliable AGB predictions. Waiting for this, using large forest inventories with low sampling rate (<0.5%) may be an efficient way to increase the global coverage of AGB maps with acceptable accuracy at kilometric resolution.

opencc-zeroDec 2012View details →

Data from: How diverse is Mitopus morio? Integrative taxonomy detects cryptic species in a small-scale sample of a widespread harvestman

Mitopus morio is a widespread harvestman species occurring in most of Europe and in moderate and cold-moderate zones of Asia and North America. The species is characterized by extreme variability in body size and leg length. As leg length is correlated with habitat temperature, M. morio has been considered as an example of Allen's rule. Recently, observations for a single location in Tyrol, Austria, indicated the absence of mating between short- and long-legged individuals. This study examines for signs of putative cryptic species in M. morio using an integrative approach that combines mating trials, amplified fragment length polymorphism whole-genome scans, mitochondrial sequences and morphometrics. The mating trials did not corroborate the initial hypothesis of a reproductive barrier associated with leg size. Both types of genetic data revealed the existence of three distinct groups, in line with the mating results but largely unrelated to leg morphology and geographical origin of specimens. Morphometric characters supporting the findings of the other disciplines were identified using a supervised approach. We infer from all data together the existence of strongly diverged cryptic lineages among the analysed individuals, cautiously interpret them as three sympatric species and conclude that in these harvestmen Allen's rule applies at different levels. Due to the unexpected amount of differentiation found within a geographical scale very small compared with the distribution of M. morio, we suggest a thorough revision of the genus prior to formal taxonomic changes. Our case study underlines the general applicability of the integrative taxonomic protocol used and highlights the relevance of several rationales implemented in the protocol.

opencc-zeroDec 2018View details →

Data from: Taxonomic and functional diversity of the co-flowering community differentially affect Cakile edentula pollination at different spatial scales

1. The number of co-flowering species, floral density and floral trait diversity can be major determinants of pollinator-mediated plant-plant interactions in a community. However, evaluation of how each one of these co-flowering components affects the pollination success of a single focal plant species, and how these effects vary at different spatial scales, is lacking. 2. Here we evaluated the effects of functional diversity (flower morphology and colour), taxonomic diversity (reflecting potential sampling effects) and flower density (conspecific and heterospecific), on the pollinator environment (i.e. visitation rate and pollinator diversity), and pollination success (i.e. pollen load size and number of pollen tubes per style) of Cakile edentula (Brassicaceae). We applied structural equation models (SEM's) at the floral-neighbourhood (plot level) and community-wide scales to uncover the factors that mediate co-flowering community effects on C. edentula pollination success. 3. We found that co-flowering community effects at the community level are more important than fine-scale floral-neighbourhood differences in mediating plant pollination success in our study species. Increasing plant functional diversity decreased pollinator visitation rate but increased the diversity of pollinator functional groups visiting C. edentula flowers. Taxonomic diversity negatively affected pollinator diversity suggesting that other unmeasured floral traits may be relevant or that single-species effects (sampling effects) may be important. Overall, our results suggest that functional floral trait diversity in a community may be the most important factor influencing pollination success of species in a community. We also found evidence for intra- and interspecific pollinator competition mediated by flower density but none of these effects seemed to have a significant impact on pollination success. 4. This study is an important step towards understanding the complexity of co-flowering community effects on the pollination success of individual plant species at multiple spatial scales. This study further reveals the potential importance of plant functional diversity in a community in helping predict competitive and facilitative interactions in co-flowering communities. 5. Synthesis. Floral density, taxonomic and functional co-flowering diversity are important drivers of pollination success in flowering plants. The effects of the co-flowering diversity on the pollination success of plant species can largely depend on the spatial scale being studied. Only evaluating the outcomes of pollinator-mediated plant-plant interactions at multiple stages of the pollination process can lead to a complete understanding of their ecological consequences in nature.

Data from: Cope's rule and the universal scaling law of ornament complexity

Luxuriant, bushy antlers, bizarre crests, and huge, twisting horns and tusks are conventionally understood as products of sexual selection. This view stems from both direct observation and from the empirical finding that the size of these structures grows faster than body size (i.e., ornament size shows positive allometry). We contend that the familiar evolutionary increase in the complexity of ornaments over time in many animal clades is decoupled from ornament size evolution. Increased body size comes with extended growth. Since growth scales to the quarter power of body size, we predicted that ornament complexity should scale according to the quarter power law as well, irrespective of the role of sexual selection in the evolution and function of the ornament. To test this hypothesis, we selected three clades (ammonites, deer, and ceratopsian dinosaurs) whose species bore ornaments that differ in terms of the importance of sexual selection to their evolution. We found that the exponent of the regression of ornament complexity to body size is the same for the three groups and is statistically indistinguishable from 0.25. We suggest that the evolution of ornament complexity is a by-product of Cope's rule. We argue that although sexual selection may control size in most ornaments, it does not influence their shape.