Understanding different dominance patterns in western Amazonian forests.

Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥2.5 cm diameter, 2609 species) to explore the relationships between local abundance, regional frequency and spatial aggregation of dominant species in four main habitat types in western Amazonia. Although the abundance-occupancy relationship is positive for the full dataset, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade-off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unravelling different dominance patterns is a research priority to direct conservation efforts in Amazonian forests.

Aridity-dependent shifts in biodiversity-stability relationships but not in underlying mechanisms.

Climate change will affect the way biodiversity influences the stability of plant communities. Although biodiversity, associated species asynchrony, and species stability could enhance community stability, the understanding of potential nonlinear shifts in the biodiversity-stability relationship across a wide range of aridity (measured as the aridity index, the precipitation/potential evapotranspiration ratio) gradients and the underlying mechanisms remain limited. Using an 8-year dataset from 687 sites in Mongolia, which included 5496 records of vegetation and productivity, we found that the temporal stability of plant communities decreased more rapidly in more arid areas than in less arid areas. The result suggests that future aridification across terrestrial ecosystems may adversely affect community stability. Additionally, we identified nonlinear shifts in the effects of species richness and species synchrony on temporal community stability along the aridity gradient. Species synchrony was a primary driver of community stability, which was consistently negatively affected by species richness while being positively affected by the synchrony between C3 and C4 species across the aridity gradient. These results highlight the crucial role of C4 species in stabilizing communities through differential responses to interannual climate variations between C3 and C4 species. Notably, species richness and the synchrony between C3 and C4 species independently regulated species synchrony, ultimately affecting community stability. We propose that maintaining plant communities with a high diversity of C3 and C4 species will be key to enhancing community stability across Mongolian grasslands. Moreover, species synchrony, species stability, species richness and the synchrony between C3 and C4 species across the aridity gradient consistently mediated the impacts of aridity on community stability. Hence, strategies aimed at promoting the maintenance of biological diversity and composition will help ecosystems adapt to climate change or mitigate its adverse effects on ecosystem stability.

Mowing increased community stability in semiarid grasslands more than either fencing or grazing.

A substantial body of empirical evidence suggests that anthropogenic disturbance can affect the structure and function of grassland ecosystems. Despite this, few studies have elucidated the mechanisms through which grazing and mowing, the two most widespread land management practices, affect the stability of natural grassland communities. In this study, we draw upon 9 years of field data from natural grasslands in northern China to investigate the effects of gazing and mowing on community stability, specifically focusing on community aboveground net primary productivity (ANPP) and dominance, which are two major biodiversity mechanisms known to characterize community fluctuations. We found that both grazing and mowing reduced ANPP in comparison to areas enclosed by fencing. Grazing reduced community stability by increasing the likelihood of single-species dominance and decreasing the relative proportion of nondominant species. In contrast, mowing reduced the productivity of the dominant species but increased the productivity of nondominant species. As a consequence, mowing improved the overall community stability by increasing the stability of nondominant species. Our study provides novel insight into understanding of the relationship between community species fluctuation-stability, with implications for ecological research and ecosystem management in natural grasslands.

Community Structure and Water Quality Assessment of Benthic Macroinvertebrates in Hongze Lake.

This study investigated the species, density, biomass and physicochemical factors of benthic macroinvertebrates in Hongze Lake from 2016 to 2020. Redundancy analysis (RDA) was used to analyze the relationship between physicochemical parameters and the community structure of macroinvertebrates. Macroinvertebrate-based indices were used to evaluate the water quality conditions in Hongze Lake. The results showed that a total of 50 benthic species (10 annelids, 21 arthropods and 19 mollusks) were collected. The community structure of benthic macroinvertebrates varied in time and space. The dominant species were Limnodrilus hoffmeisteri (L.hoffmeisteri), Corbicula fluminea (C.fluminea), Nephtys oligobranchia (N.oligobranchia). In 2016, arthropods such as Grandidierella sp. were the dominant species of benthos in Hongze Lake while annelids and mollusks dominated from 2017 to 2020, such as L.hoffmeisteri, N.oligobranchia, C.fluminea. The benthic fauna of Chengzi Lake and Lihewa District were relatively abundant and showed slight variation, while the benthic macroinvertebrates of the Crossing the water area were few and varied greatly. RDA showed that changes in benthic macroinvertebrate structure were significantly correlated with dissolved oxygen (DO), Pondus Hydrogenii (pH) and transparency (SD). The Shannon Wiener, Pielou, and Margalef indices indicate that Hongze Lake is currently in a moderately polluted state. Future studies should focus on the combined effects of various physicochemical indicators and other environmental factors on benthic communities.

Warming-driven indirect effects on alpine grasslands: short-term gravel encroachment rapidly reshapes community structure and reduces community stability.

The community stability is the main ability to resist and be resilient to climate changes. In a world of climate warming and melting glaciers, alpine gravel encroachment was occurring universally and threatening hillside grassland ecosystem. Gravel encroachment caused by climate warming and glacial melting may alter community structure and community stability in alpine meadow. Yet, the effects of climate warming-induced gravel encroachment on grassland communities are unknown. Here, a 1-year short-term field experiment was conducted to explore the early stage drive process of gravel encroachment on community structure and stability at four different gravel encroachment levels 0%, 30%, 60%, and 90% gravel coverage at an alpine meadow on the Qinghai Tibetan Plateau, by analyzing the changes of dominant species stability and species asynchrony to the simulated gravel encroachment processes. Gravel encroachment rapidly changed the species composition and species ranking of alpine meadow plant community in a short period of time. Specifically, community stability of alpine meadow decreased by 61.78-79.48%, which may be due to the reduced dominant species stability and species asynchrony. Species asynchrony and dominant species stability were reduced by 2.65-17.39% and 46.51-67.97%, respectively. The results of this study demonstrate that gravel encroachment presents a severe negative impact on community structure and stability of alpine meadow in the short term, the longer term and comprehensive study should be conducted to accurate prediction of global warming-induced indirect effects on alpine grassland ecosystems.

Dynamics of the natural enemy community of Hyphantria cunea (Lepidoptera: Erebidae) in Dandong, China.

This study aims to explore the composition of natural enemy species in the fall webworm, Hyphantria cunea (Drury) population and the dynamics of its natural enemy community in Dandong, Liaoning Province, China, where it was first reported. We collected the natural enemy of eggs, larvae, and pupae of H. cunea on host trees at 12 survey sites from June 2019 to October 2020. The results showed that the community consists of 34 species: 20 predatory species, including 15 spiders and 5 insects, and 14 parasitic species, including 10 parasitic wasps and 4 parasitic flies. The top 3 dominant species based on the importance value index for both parasitic and predatory species were Pediobius pupariae > Chouioia cunea > Cotesia gregalis in the natural enemy community of H. cunea. Analysis of all 3 principal components by principal component analysis showed that Clubionidae sp. 1, Parena cavipennis, or other predators were the main factors affecting the natural enemy community. Analysis of the community structure parameters of the H. cunea natural enemy community in different developmental stages across generations revealed the following: (i) Compared with the degree of complexity of the egg and pupal stages, the larval stage was the highest. (ii) The complexity was determined by means of comprehensive evaluation: first-generation larvae in 2020 > first-generation larvae in 2019 > second-generation larvae in 2020 > second-generation larvae in 2019. These results clarify the dynamics of natural enemy species, coevolution with the host in the invaded habitat of H. cunea and development of biological control technologies.

Next-Generation Sequencing for Evaluating the Soil Nematode Diversity and Its Role in Composting Processes.

Biodiversity within composting systems involves a variety of microorganisms including nematodes. In the research, nematode populations were monitored within six simultaneously operating composting processes. These processes involved varying proportions of feedstock materials. The primary objective was to evaluate the consistency of nematode community succession patterns across the composting processes over a time of 3 months. During the study, samples were taken every month to isolate nematodes, determine the population density of the five trophic groups (per genus) and determine the dominant nematode species. It was shown that the bacterial-feeding community maintained dominance, while the fungus-feeding nematodes gradually increased in dominance as the maturation process progressed. The presence of predatory nematodes Mononchoides which were initially absent, along with the total absence of parasitic nematodes in the late stages of waste stabilization, serves as strong evidence for the reliable evaluation of the biodegradable waste processing level. Based on the obtained results, it is evident that the succession of nematode communities holds promise as a reliable method for evaluating compost maturity.

Fungal dynamic changes in naturally fermented 'Kyoho' grape juice.

The 'Kyoho' grape (Vitaceae, Plantae) has large ears, plenty of flesh, and rich nutrition and is planted across a large area in China. There are few reports on this variety in winemaking, especially on the dynamic changes of fungi in the wine fermentation broth. In this study, we used the 'Kyoho' grapes as raw materials and adopted a high throughput to analyze dynamic changes in fungal species composition of the natural fermentation broth at four time points: day 1 (D1P), day 3 (D3P), day 5 (D5P), and day 15 (D15P). Changes in fungal metabolic pathways and dominant yeasts were also analyzed. A total of 78 families, 110 genera, and 137 species were detected, in the natural fermentation broth samples. Forty-nine families, 60 genera, and 72 species were found in the control check (CK). A total of 66 differential metabolic pathways were enriched; of those, 41 were up-regulated compared to CK, such as CDP-diacylglycerol biosynthesis I (PWY 5667), chitin degradation to ethanol (PWY 7118), and the super pathway of phosphatidate biosynthesis (PWY 7411). Changes in fungal metabolic pathways were in line with the dynamic changes of dominant yeast species in the whole process of fermentation. Pichia kluyveri, P. membranifaciens, and Citeromyces matritensis are the dominant species in the later stages of natural fermentation. These yeast species may play vital roles in the 'Kyoho' wine industry in the future.

The ecosystem impacts of dominant species exclusion in a prairie restoration.

Dominant species often have disproportionately high abundance in restored communities compared to native remnants, which potentially could reduce the conservation value of restorations. Research is needed to determine how the abundance of dominant species in restoration plantings affects community assembly, species diversity, and ecosystem function. Most studies of dominant species in grasslands were modeled after experiments on keystone species, using the short-term experimental removal of dominants to test their functional role in ecosystems. However, the removal of established dominants constitutes a major disturbance that may influence the interpretation of their long-term functional impact. To address this, we experimentally assembled high-diversity tallgrass prairie communities that included or excluded the predicted dominant species (Andropogon gerardii and Sorghastrum nutans) from the seed mix at the time of planting, but without further manipulation of community composition. From 2013 to 2019, we measured several ecosystem functions and community dynamics in the presence or absence of dominants. Communities that included the dominant species had lower species richness, greater aboveground biomass, and reduced light availability at the soil surface. Dominant species presence also increased soil nutrient availability and rates of litter decomposition, although dominant grass litter decomposed more slowly than litter from other common species in both treatments. In the absence of the dominant grasses, communities were instead dominated by a common unplanted forb, Solidago altissima, and there was partial compensation in ecosystem functioning in these forb-dominated communities. The effects of dominant species exclusion may only be apparent in long-term studies of experimentally assembled communities that avoid the legacy effects associated with removal experiments. Furthermore, our results suggest that prairie restorations that limit or exclude the dominant grasses in seed mixes may achieve higher species diversity, increasing the conservation value of these systems.

Litter nitrogen concentration changes mediate effects of drought and plant species richness on litter decomposition.

Biodiversity loss, exotic plant invasion and climatic change are three important global changes that can affect litter decomposition. These effects may be interactive and these global changes thus need to be considered simultaneously. Here, we assembled herbaceous plant communities with five species richness levels (1, 2, 4, 8 or 16) and subjected them to a drought treatment (no, moderate or intensive drought) that was factorially combined with an invasion treatment (presence or absence of the non-native Symphyotrichum subulatum). We collected litter of these plant communities and let it decompose for 9 months in the plant communities from which it originated. Drought decreased litter decomposition, while invasion by S. subulatum had little impact. Increasing species richness decreased litter decomposition except under intensive drought. A structural equation model showed that drought and species richness affected litter decomposition indirectly through changes in litter nitrogen concentration rather than by altering quantity and diversity of soil meso-fauna or soil physico-chemical properties. The slowed litter decomposition under high species diversity originated from a sampling effect, specifically from low litter nitrogen concentrations in the two dominant species. We conclude that effects on litter decomposition rates that are mediated by changing concentrations of the limiting nutrient in litter need to be considered when predicting effects of global changes such as plant diversity loss.

Variable Optimization of Seaweed Spectral Response Characteristics and Species Identification in Gouqi Island.

Probing the coverage and biomass of seaweed is necessary for achieving the sustainable utilization of nearshore seaweed resources. Remote sensing can realize dynamic monitoring on a large scale and the spectral characteristics of objects are the basis of remote sensing applications. In this paper, we measured the spectral data of six dominant seaweed species in different dry and wet conditions from the intertidal zone of Gouqi Island: Ulva pertusa, Sargassum thunbergii, Chondrus ocellatus, Chondria crassiaulis Harv., Grateloupia filicina C. Ag., and Sargassum fusifarme. The different seaweed spectra were identified and analyzed using a combination of one-way analysis of variance (ANOVA), support vector machines (SVM), and a fusion model comprising extreme gradient boosting (XGBoost) and SVM. In total, 14 common spectral variables were used as input variables, and the input variables were filtered by one-way ANOVA. The samples were divided into a training set (266 samples) and a test set (116 samples) at a ratio of 3:1 for input into the SVM and fusion model. The results showed that when the input variables were the normalized difference vegetation index (NDVI), ratio vegetation index (RVI), Vre, Abe, Rg, Lre, Lg, and Lr and the model parameters were g = 1.30 and c = 2.85, the maximum discrimination rate of the six different wet and dry states of seaweed was 74.99%, and the highest accuracy was 93.94% when distinguishing between the different seaweed phyla (g = 6.85 and c = 2.55). The classification of the fusion model also shows similar results: The overall accuracy is 73.98%, and the mean score of the different seaweed phyla is 97.211%. In this study, the spectral data of intertidal seaweed with different dry and wet states were classified to provide technical support for the monitoring of coastal zones via remote sensing and seaweed resource statistics.

Assembly dynamics of East Asian subtropical evergreen broadleaved forests: New insights from the dominant Fagaceae trees.

The dominant species of a biome can be regarded as its genuine indicator. Evergreen broadleaved forests (EBLFs) in subtropical East Asia harbor high levels of species biodiversity and endemism and are vital to regional carbon storage and cycling. However, the historical assembly of this unique biome is still controversial. Fagaceae is the most essential family in East Asian subtropical EBLFs and its dominant species are vital for the existence of this biome. Here, we used the dominant Fagaceae species to shed light on the dynamic process of East Asian subtropical EBLFs over time. Our results indicate high precipitation in summer and low temperature in winter are the most influential climatic factors for the distribution of East Asian subtropical EBLFs. Modern East Asian subtropical EBLFs did not begin to appear until 23 Ma, subsequently experienced a long-lasting development in the Miocene and markedly deteriorated at about 4 Ma, driven jointly by orogenesis and paleoclimate. We also document that there is a lag time between when one clade invaded the region and when its members become dominant species within the region. This study may improve our ability to predict and mitigate the threats to biodiversity of East Asian subtropical EBLFs and points to a new path for future studies involving multidisciplinary methods to explore the assembly of regional biomes.

Wild insect diversity increases inter-annual stability in global crop pollinator communities.

While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability.

Defining codominance in plant communities.

Species dominance and biodiversity in plant communities have received considerable attention and characterisation. However, species codominance, while often alleged, is seldom defined or quantified. Codominance is a common phenomenon and is likely to be an important driver of community structure, ecosystem function and the stability of both. Here we review the use of the term 'codominance' and find inconsistencies in its use, suggesting that the scientific community currently lacks a universal understanding of codominance. We address this issue by: (1) qualitatively defining codominance as mostly shared abundance that is distinctively isolated within a subset of a community, and (2) presenting a novel metric for quantifying the degree to which relative abundances are shared among a codominant subset of plant species, while also accounting for the remaining species within a plant community. Using both simulated and real-world data, we then demonstrate the process of applying the codominance metric to compare communities and to generate a quantitatively defensible subset of species to consider codominant within a community. We show that our metric effectively distinguishes the degree of codominance between four types of grassland ecosystems as well as simulated ecosystems with varying degrees of abundance sharing among community members. Overall, we make the case that increased research focusses on the conditions under which codominance occurs and the consequences for species coexistence, community structure and ecosystem function that would considerably advance the fields of community and ecosystem ecology.

Distinctive patterns and signals at major environmental events and collapse zone boundaries.

We studied the patterns of pre-collapse communities, the small-scale and the large-scale signals of collapses, and the environmental events before the collapses using four paleoecological and one modern data series. We applied and evaluated eight indicators in our analysis: the relative abundance of species, hierarchical cluster analysis, principal component analysis, total abundance, species richness, standard deviation (without a rolling window), first-order autoregression, and the relative abundance of the dominant species. We investigated the signals at the probable collapse triggering unusual environmental events and at the collapse zone boundaries, respectively. We also distinguished between pulse and step environmental events to see what signals the indicators give at these two different types of events. Our results show that first-order autoregression is not a good environmental event indicator, but it can forecast or indicate the collapse zones in climate change. The rest of the indicators are more sensitive to the pulse events than to the step events. Step events during climate change might have an essential role in initiating collapses. These events probably push the communities with low resilience beyond a critical threshold, so it is crucial to detect them. Before collapses, the total abundance and the species richness increase, the relative abundance of the species decreases. The hierarchical cluster analysis and the relative abundance of species together designate the collapse zone boundaries. We suggest that small-scale signals should be involved in analyses because they are often earlier than large-scale signals.

Nitrogen addition increases sexual reproduction and improves seedling growth in the perennial rhizomatous grass Leymus chinensis.

BACKGROUND: The Eurasian steppe is an important vegetation type characterized by cold, arid and nitrogen poor conditions. At the Eastern edge, including in the Songnen grassland, the vegetation is dominated by Leymus chinensis (henceforth L. chinensis) and is increasing threatened by elevated anthropogenic nitrogen deposition. L. chinensis is a perennial grass that mainly reproduces vegetatively and its sexual reproduction is limited. However, sexual reproduction plays an important role influencing colonization after large disturbances. To develop an understanding of how elevated nitrogen deposition changes the plant community structure and functioning we need a better understanding how sexual reproduction of L. chinensis changes with nitrogen enrichment. Here we report on a field experiment where we added 10 g N m- 2 yr- 1 and examined changes in seed traits, seed germination and early seedling growth. RESULTS: Nitrogen addition increased seed production by 79%, contributing to this seed increases were a 28% increase in flowering plant density, a 40% increase in seed number per plant and a 11% increase in seed weight. Seed size increased with a 42% increase in large seeds and a 49% decrease in the smallest seed size category. Seed germination success improved by 10% for small seeds and 18% for large seeds. Combined, the increased in seed production and improved seed quality doubled the potential seed germination. Subsequent seedling above and below-ground biomass also significantly increased. CONCLUSIONS: All aspects of L. chinensis sexual reproduction increased with nitrogen addition. Thus, L. chinensis competitive ability may increase when atmospheric nitrogen deposition increases, which may further reduce overall plant diversity in the low diversity Songnen grasslands.

Biotic stability mechanisms in Inner Mongolian grassland.

Biotic mechanisms associated with species diversity are expected to stabilize communities in theoretical and experimental studies but may be difficult to detect in natural communities exposed to large environmental variation. We investigated biotic stability mechanisms in a multi-site study across Inner Mongolian grassland characterized by large spatial variations in species richness and composition and temporal fluctuations in precipitation. We used a new additive-partitioning method to separate species synchrony and population dynamics within communities into different species-abundance groups. Community stability was independent of species richness but was regulated by species synchrony and population dynamics, especially of abundant species. Precipitation fluctuations synchronized population dynamics within communities, reducing their stability. Our results indicate generality of biotic stability mechanisms in natural ecosystems and suggest that for accurate predictions of community stability in changing environments uneven species composition should be considered by partitioning stabilizing mechanisms into different species-abundance groups.

Genetic and functional variation across regional and local scales is associated with climate in a foundational prairie grass.

Global change forecasts in ecosystems require knowledge of within-species diversity, particularly of dominant species within communities. We assessed site-level diversity and capacity for adaptation in Bouteloua gracilis, the dominant species in the Central US shortgrass steppe biome. We quantified genetic diversity from 17 sites across regional scales, north to south from New Mexico to South Dakota, and local scales in northern Colorado. We also quantified phenotype and plasticity within and among sites and determined the extent to which phenotypic diversity in B. gracilis was correlated with climate. Genome sequencing indicated pronounced population structure at the regional scale, and local differences indicated that gene flow and/or dispersal may also be limited. Within a common environment, we found evidence of genetic divergence in biomass-related phenotypes, plasticity, and phenotypic variance, indicating functional divergence and different adaptive potential. Phenotypes were differentiated according to climate, chiefly median Palmer Hydrological Drought Index and other aridity metrics. Our results indicate conclusive differences in genetic variation, phenotype, and plasticity in this species and suggest a mechanism explaining variation in shortgrass steppe community responses to global change. This analysis of B. gracilis intraspecific diversity across spatial scales will improve conservation and management of the shortgrass steppe ecosystem in the future.

Marine fauna sort at fine resolution in an ecotone of shifting wetland foundation species.

Climate-driven global change is shifting the distribution and abundance of foundation species that form the base of ecosystems. The corresponding responses of inhabitant species to shifts in habitat-forming species are poorly understood, however we expect community responses to depend on how species perceive habitat patches and sort among them, particularly along range edges. We used the poleward shift of a mangrove-marsh ecotone to evaluate sorting of marine macrofauna (small fish and decapod crustaceans) among vegetation patches at a series of nested scales. Within the mangrove-marsh ecotone, we deployed retrievable panels of artificial vegetation structures mimicking a marsh grass and two mangrove species in patches dominated by each of these three foundation species. Over six months, we observed macrofaunal sorting by physical structure, isolated on panels, and by patch type, which included stand-level attributes such as production, shading, and chemical cues. We found multiscale partitioning of macrofaunal community composition by site (kilometer scale), vegetation type, and patch type with stand attributes (meters), and physical structure (centimeters). Differences in community composition between vegetation types at each scale indicated that mangroves and marsh grass differ as habitat for marine fauna and that wetland inhabitants can distinguish and sort among fine-grain habitat patches that co-occur within the ecotone. Such differences suggest that shifts in wetland vegetation are consequential for the protection and management of coastal populations. Studies that determine which habitat attributes shape inhabitant fauna associations can help reveal not just the spatial grain at which inhabitants associate with emerging frontier habitat but also how the redistribution of foundation species shapes the pace and resolution of broader community change.

Reliable estimates of beta diversity with incomplete sampling.

Beta diversity, the compositional variation among communities or assemblages, is crucial to understanding the principles of diversity assembly. The mean pairwise proportional dissimilarity expresses overall heterogeneity of samples in a data set and is among the most widely used and most robust measures of beta diversity. Obtaining a complete list of taxa and their abundances requires substantial taxonomic expertise and is time consuming. In addition, the information is generally incomplete due to sampling biases. Based on the concept of the ecological significance of dominant taxa, we explore whether determining proportional dissimilarity can be simplified based on dominant species. Using simulations and six case studies, we assess the correlation between complete community compositional data and reduced subsets of a varying number of dominant species. We find that gross beta diversity is usually depicted accurately when only the 80th percentile or five of the most abundant species of each site is considered. In data sets with very high evenness, at least the 10 most abundant species should be included. Focusing on dominant species also maintains the rank-order of beta diversity among sites. Our new approach will allow ecologists and paleobiologists to produce a far greater amount of data on diversity patterns with less time and effort, supporting conservation studies and basic science.