Browsing by Subject "BETA DIVERSITY"

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  • Macias-Hernandez, Nuria; Ramos, Cândida; Domènech, Marc; Febles, Sara; Santos, Irene; Arnedo, Miquel A.; Borges, Paulo A. V.; Emerson, Brent C.; Cardoso, Pedro (2020)
    Background There is an increasing demand for databases including species trait information for biodiversity and community ecology studies. The existence of trait databases is useful for comparative studies within taxa or geographical regions, but there is low availability of databases for certain organisms. Here we present an open access functional trait database for spiders from Macaronesia and the Iberian Peninsula, recording several morphological and ecological traits related to the species life histories, microhabitat and trophic preferences. New information We present a database that includes 12 biological traits for 506 spider species present in natural forests of the Iberian Peninsula (Spain) and three Macaronesian archipelagoes (Azores, Madeira and Canary Islands). The functional trait database consists of two sections: 1. individual-level data for six morphological traits (total body size, prosoma length, prosoma width, prosoma height, tibia I length and fang length), based on direct measurements of 2844 specimens of all spider species; and 2. species-level aggregate data for 12 traits (same 6 morphological traits as in the previous section plus dispersal ability, vertical stratification, circadian activity, foraging strategy, trophic specialization and colonization status), based on either the average of the direct measurements or bibliographic searches. This functional trait database will serve as a data standard for currently ongoing analyses that require trait and functional diversity statistics.
  • Mammola, Stefano; Carmona, Carlos P.; Guillerme, Thomas; Cardoso, Pedro (2021)
    The use of functional diversity analyses in ecology has grown exponentially over the past two decades, broadening our understanding of biological diversity and its change across space and time. Virtually all ecological sub-disciplines recognise the critical value of looking at species and communities from a functional perspective, and this has led to a proliferation of methods for estimating contrasting dimensions of functional diversity. Differences between these methods and their development generated terminological inconsistencies and confusion about the selection of the most appropriate approach for addressing any particular ecological question, hampering the potential for comparative studies, simulation exercises and meta-analyses. Two general mathematical frameworks for estimating functional diversity are prevailing: those based on dissimilarity matrices (e.g. Rao entropy, functional dendrograms) and those relying on multidimensional spaces, constructed as either convex hulls or probabilistic hypervolumes. We review these frameworks, discuss their strengths and weaknesses and provide an overview of the main R packages performing these calculations. In parallel, we propose a way for organising functional diversity metrics in a unified scheme to quantify the richness, divergence and regularity of species or individuals under each framework. This overview offers a roadmap for confidently approaching functional diversity analyses both theoretically and practically.
  • Jiang, Yonglei; Lei, Yanbao; Yang, Yan; Korpelainen, Helena; Niinemets, Ulo; Li, Chunyang (2018)
    Despite the ubiquitous distributions and critical ecological functions of microorganisms in pedogenesis and ecosystem development in recently deglaciated areas, there are contrasting successional trajectories among bacteria and fungi, but the driving forces of community assembly still remain poorly resolved. In this study, we analyzed both bacterial and fungal lineages associated with seven different stages in the Hailuogou Glacier Chronosequence, to quantify their taxonomic composition and successional dynamics, and to decipher the relative contribution from the bottom-up control of soil nutrients and altered vegetation as well as top-down pressures from nematode grazers. Co-occurrence networks showed that the community complexity for both bacteria and fungi typically peaked at the middle chronosequence stages. The overlapping nodes mainly belonged to Proteobacteria and Acidobacteria in bacteria, and Ascomycota and Basidiomycota in fungi, which was further supported by the indicator species analysis. Variation in partitioning and structural equation modeling suggested that edaphic properties were the primary agents shaping microbial community structures, especially at the early stages. The importance of biotic factors, including plant richness and nematode feeding, increased during the last two stages along with the establishment of a coniferous forest, eventually governing the turnover of fungal communities. Moreover, bacterial communities exhibited a more compact network topology during assembly, thus supporting determinism, whereas the looser clustering of fungal communities illustrated that they were determined more by stochastic processes. These pieces of evidence collectively reveal divergent successional trajectories and driving forces for soil bacterial and fungal communities along a glacier forefield chronosequence.
  • Ordynets, Alexander; Heilmann-Clausen, Jacob; Savchenko, Anton; Baessler, Claus; Volobuev, Sergey; Akulov, Olexander; Karadelev, Mitko; Kotiranta, Heikki; Saitta, Alessandro; Langer, Ewald; Abrego, Nerea (2018)
    Aim: Aphyllophoroid fungi are associated with plants, either using plants as a resource (as parasites or decomposers) or as symbionts (as mycorrhizal partners). In spite of their strong association with plants, it is unknown how much plant distributions determine their biogeographical patterns compared with environmental factors such as climate and human land use. In this study, our aims are to (1) describe the spatial diversity patterns of aphyllophoroid fungi in Europe and (2) identify the factors shaping these patterns. Location: Europe, as well as the adjacent Subarctic to Arctic islands (Greenland, Faroe Islands, Iceland, Svalbard), Palestine and the south-east coast of the Caspian Sea. Methods: We compiled a dataset consisting of 14,030 fruitbody occurrences of 1,491 aphyllophoroid fungal species from 39 geographical areas (17 countries) belonging to eight biogeographical regions. We assessed the differences in fungal species richness and overall diversity and its nestedness and turnover components across biogeographical regions of Europe, as well as between southern and northern Europe (based on geographical latitude of 50 degrees as threshold). We used cluster and ordination analyses to classify the European aphyllophoroid communities biogeographically and evaluated the importance of climate, host-tree species, topography and human land-use intensity in explaining biogeographical variation. Results: The importance of biogeographical regions in determining European aphyllophoroid fungal communities varies for different diversity components. Species richness and nestedness are best explained by plant-based biogeographical regions, whereas overall beta diversity and species turnover are driven mostly by variation in climate, and nestedness mostly by tree species occupancy. Beta-diversity patterns of aphyllophoroid fungi do not differ between southern and northern Europe. Main conclusions: At the continental scale, aphyllophoroid fungi are less shaped by historical legacies than vascular plant and animal communities, and trends of overall beta diversity in southern and northern Europe are similar to patterns found for bryophytes.
  • Graco-Roza, Caio; Santos, Juliana B. O.; Huszar, Vera L. M.; Domingos, Patricia; Soininen, Janne; Marinho, Marcelo Manzi (2020)
    Environmental heterogeneity (EH) in space and time promotes niche-partition, which leads to high variation in biological communities, such as in algae. In streams, EH is highly related to the intensity of the water flow and may lead to community variation mainly during the low flow conditions. Despite the wide knowledge on the responses of phytoplankton communities to EH in lentic and semi-lentic systems, studies of riverine phytoplankton community variation are still scarce. Here, we first investigated the relationship between phytoplankton community variation and EH in different courses of the river and between seasons. We expected that under low or intermediate flow conditions, there is a positive correlation between community variation and EH. Alternatively, we did not expect any relationship between EH and community variation under high flow condition because stronger downstream transport would mask environmental filtering. We sampled nine sites monthly (May 2012 to April 2013) in a tropical river of Brazilian Southeast. We calculated EH from abiotic data whereas for community variation, here community distinctiveness (CD), we used Sorensen (CDSor) and Bray-Curtis (CDBray) dissimilarities. Differences in EH, CDSor and CDBray were tested at between-season and among-course levels. We found lower distinctiveness during the dry season when EH was the highest. Contrastingly, phytoplankton CD was the highest even when EH was low during the wet season. We found that this pattern raised from the increasing in individuals dispersal during the wet season, promoting mass effects. Finally, our results thus reject the first hypothesis and show a negative relationship between EH and distinctiveness. However, results support our alternative hypothesis and show that during the wet season, distinctiveness is not driven by EH. These results provide new insights into how EH drives community variation, being useful for both basic research about riverine algal communities and biomonitoring programs using phytoplankton communities as bioindicators. (C). 2019 Elsevier B.V. All rights reserved.
  • He, Siwen; Soininen, Janne; Chen, Kai; Wang, Beixin (2020)
    Metacommunity theory provides a useful framework to describe the underlying factors (e.g., environmental and dispersal-related factors) influencing community structure. The strength of these factors may vary depending on the properties of the region studied (e.g., environmental heterogeneity and spatial location) and considered biological groups. Here, we examined environmental and dispersal-related controls of stream macroinvertebrates and diatoms in three regions in China using the distance-decay relationship analysis. We performed analyses for the whole stream network and separately for two stream network locations (headwater and downstream sites) to test the network position hypothesis (NPH), which states that the strength of environmental and dispersal-related controls varies between headwater and downstream communities. Community dissimilarities were significantly related to environmental distances, but not geographical distances. These results suggest that communities are structured strongly by environmental filtering, but weakly by dispersal-related factors such as dispersal limitation. More importantly, we found that, at the whole network scale, environmental control was the highest in the regions with highest environmental heterogeneity. Results further showed that the influence of environmental control was strong in both headwaters and downstream sites, whereas spatial control was generally weak in all sites. This suggests a lack of consistent support for the NPH in our studied stream networks. Moreover, we found that local-scale variables relative to basin-scale variables better explained community dissimilarities for diatoms than for macroinvertebrates. This indicates that diatoms and macroinvertebrates responded to environment at different scales. Collectively, these results suggest that the importance of drivers behind the metacommunity assembly varied among regions with different level of environmental heterogeneity and between organism groups, potentially indicating context dependency among stream systems and taxa.
  • Schartau, Ann Kristin; Mariash, Heather L.; Christoffersen, Kirsten S.; Bogan, Daniel; Dubovskaya, Olga P.; Fefilova, Elena B.; Hayden, Brian; Ingvason, Haraldur R.; Ivanova, Elena A.; Kononova, Olga N.; Kravchuk, Elena S.; Lento, Jennifer; Majaneva, Markus; Novichkova, Anna A.; Rautio, Milla; Ruhland, Kathleen M.; Shaftel, Rebecca; Smol, John P.; Vrede, Tobias; Kahilainen, Kimmo K. (2022)
    Arctic freshwaters are facing multiple environmental pressures, including rapid climate change and increasing land-use activities. Freshwater plankton assemblages are expected to reflect the effects of these stressors through shifts in species distributions and changes to biodiversity. These changes may occur rapidly due to the short generation times and high dispersal capabilities of both phyto- and zooplankton. Spatial patterns and contemporary trends in plankton diversity throughout the circumpolar region were assessed using data from more than 300 lakes in the U.S.A. (Alaska), Canada, Greenland, Iceland, the Faroe Islands, Norway, Sweden, Finland, and Russia. The main objectives of this study were: (1) to assess spatial patterns of plankton diversity focusing on pelagic communities; (2) to assess dominant component of beta diversity (turnover or nestedness); (3) to identify which environmental factors best explain diversity; and (4) to provide recommendations for future monitoring and assessment of freshwater plankton communities across the Arctic region. Phytoplankton and crustacean zooplankton diversity varied substantially across the Arctic and was positively related to summer air temperature. However, for zooplankton, the positive correlation between summer temperature and species numbers decreased with increasing latitude. Taxonomic richness was lower in the high Arctic compared to the sub- and low Arctic for zooplankton but this pattern was less clear for phytoplankton. Fennoscandia and inland regions of Russia represented hotspots for, respectively, phytoplankton and zooplankton diversity, whereas isolated regions had lower taxonomic richness. Ecoregions with high alpha diversity generally also had high beta diversity, and turnover was the most important component of beta diversity in all ecoregions. For both phytoplankton and zooplankton, climatic variables were the most important environmental factors influencing diversity patterns, consistent with previous studies that examined shorter temperature gradients. However, barriers to dispersal may have also played a role in limiting diversity on islands. A better understanding of how diversity patterns are determined by colonisation history, environmental variables, and biotic interactions requires more monitoring data with locations dispersed evenly across the circumpolar Arctic. Furthermore, the importance of turnover in regional diversity patterns indicates that more extensive sampling is required to fully characterise the species pool of Arctic lakes.
  • Borges, Paulo A. V.; Cardoso, Pedro; Kreft, Holger; Whittaker, Robert J.; Fattorini, Simone; Emerson, Brent C.; Gil, Artur; Gillespie, Rosemary G.; Matthews, Thomas J.; Santos, Ana M. C.; Steinbauer, Manuel J.; Thebaud, Christophe; Ah-Peng, Claudine; Amorim, Isabel R.; Aranda, Silvia Calvo; Arroz, Ana Moura; Azevedo, Jose Manuel N.; Boieiro, Mario; Borda-de-Agua, Luis; Carvalho, Jose Carlos; Elias, Rui B.; Fernandez-Palacios, Jose Maria; Florencio, Margarita; Gonzalez-Mancebo, Juana M.; Heaney, Lawrence R.; Hortal, Joaquin; Kueffer, Christoph; Lequette, Benoit; Martin-Esquivel, Jose Luis; Lopez, Heriberto; Lamelas-Lopez, Lucas; Marcelino, Jose; Nunes, Rui; Oromi, Pedro; Patino, Jairo; Perez, Antonio J.; Rego, Carla; Ribeiro, Servio P.; Rigal, Francois; Rodrigues, Pedro; Rominger, Andrew J.; Santos-Reis, Margarida; Schaefer, Hanno; Sergio, Cecilia; Serrano, Artur R. M.; Sim-Sim, Manuela; Stephenson, P. J.; Soares, Antonio O.; Strasberg, Dominique; Vanderporten, Alain; Vieira, Virgilio; Gabriel, Rosalina (2018)
    Islands harbour evolutionary and ecologically unique biota, which are currently disproportionately threatened by a multitude of anthropogenic factors, including habitat loss, invasive species and climate change. Native forests on oceanic islands are important refugia for endemic species, many of which are rare and highly threatened. Long-term monitoring schemes for those biota and ecosystems are urgently needed: (i) to provide quantitative baselines for detecting changes within island ecosystems, (ii) to evaluate the effectiveness of conservation and management actions, and (iii) to identify general ecological patterns and processes using multiple island systems as repeated 'natural experiments'. In this contribution, we call for a Global Island Monitoring Scheme (GIMS) for monitoring the remaining native island forests, using bryophytes, vascular plants, selected groups of arthropods and vertebrates as model taxa. As a basis for the GIMS, we also present new, optimized monitoring protocols for bryophytes and arthropods that were developed based on former standardized inventory protocols. Effective inventorying and monitoring of native island forests will require: (i) permanent plots covering diverse ecological gradients (e.g. elevation, age of terrain, anthropogenic disturbance); (ii) a multiple-taxa approach that is based on standardized and replicable protocols; (iii) a common set of indicator taxa and community properties that are indicative of native island forests' welfare, building on, and harmonized with existing sampling and monitoring efforts; (iv) capacity building and training of local researchers, collaboration and continuous dialogue with local stakeholders; and (v) long-term commitment by funding agencies to maintain a global network of native island forest monitoring plots.
  • Carvalho, Jose C.; Cardoso, Pedro; Rigal, Francois; Triantis, Kostas A.; Borges, Paulo A. V. (2015)
    A key challenge in island biogeography is to quantity the role of dispersal in shaping biodiversity patterns among the islands of a given archipelago. Here, we propose such a framework. Dispersal within oceanic archipelagos may be conceptualized as a spatio-temporal process dependent on: (1) the spatial distribution of islands, because the probability of successful dispersal is inversely related to the spatial distance between islands and (2) the chronological sequence of island formation that determines the directional asymmetry of dispersal (hypothesized to be predominantly from older to younger islands). From these premises, directional network models may be constructed, representing putative connections among islands. These models may be translated to eigenfunctions in order to be incorporated into statistical analysis. The framework was tested with 12 datasets from the Hawaii, Azores, and Canaries. The explanatory power of directional network models for explaining species composition patterns, assessed by the Jaccard dissimilarity index, was compared with simpler time-isolation models. The amount of variation explained by the network models ranged from 5.5% (for Coleoptera in Hawaii) to 60.2% (for Pteridophytes in Canary Islands). In relation to the four studied taxa, the variation explained by network models was higher for Pteridophytes in the three archipelagos. By the contrary, small fractions of explained variation were observed for Coleoptera (5.5%) and Araneae (8.6%) in Hawaii. Time-isolation models were, in general, not statistical significant and explained less variation than the equivalent directional network models for all the datasets. Directional network models provide a way for evaluating the spatio-temporal signature of species dispersal. The method allows building scenarios against which hypotheses about dispersal within archipelagos may be tested. The new framework may help to uncover the pathways via which species have colonized the islands of a given archipelago and to understand the origins of insular biodiversity.
  • Heino, Jani; Melo, Adriano S.; Jyrkänkallio-Mikkola, Jenny; Petsch, Danielle Katharine; Saito, Victor Satoru; Tolonen, Kimmo T.; Bini, Luis Mauricio; Landeiro, Victor Lemes; Freire Silva, Thiago Sanna; Pajunen, Virpi; Soininen, Janne; Siqueira, Tadeu (2018)
    Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scales of local stream sites, drainage basins and entire regions. We standardized the spatial extent of the study areas by resampling regional richness based on subsets of sites with similar extents. We examined differences in genus richness and assemblage abundance patterns between the regions using graphical and statistical modelling approaches. Results: We found that while genus accumulation and rank-abundance curves were relatively similar at the regional scale between Finland and Brazil, regional genus richness was higher in the latter but regional abundance much higher in the former region. These regional patterns for richness and abundance were reproduced by basin and local genus richness that were higher in Brazil than in Finland, and assemblage abundance that was much higher in Finland than in Brazil. The magnitude of the difference in genus richness between Brazil and Finland tended to increase from local through basin to regional scales. Main conclusions: Our findings suggest that factors related to evolutionary diversification might explain differences in genus richness between these two climatically different regions, whereas higher nutrient concentrations of stream waters might explain the higher abundance of insects in Finland than in Brazil.
  • Kaarlejarvi, Elina; Salemaa, Maija; Tonteri, Tiina; Merila, Paivi; Laine, Anna-Liisa (2021)
    Aim The diversity and composition of natural communities are rapidly changing due to anthropogenic disturbances. Magnitude of this compositional reorganization varies across the globe, but reasons behind the variation remain largely unknown. Disturbances induce temporal turnover by stimulating species colonizations, causing local extinctions, altering dominance structure, or all of these. We test which of these processes drive temporal community changes, and whether they are constrained by natural environmental gradients. Moreover, we assess to what degree identity shifts translate to changes in dominance structure. Location Finland. Time period Observations 1985-2006, disturbance history > 140 years. Major taxa studied Vascular plants. Methods We investigated temporal turnover of boreal forest understorey in response to disturbance, here forest management, along a soil fertility gradient. We disentangle the roles of species gains, losses and abundance changes in driving temporal turnover in response to and after disturbance by comparing turnover rates in different forest age categories along a fertility gradient. We quantify temporal turnover using richness-based complement of Jaccard's similarity index and proportional-abundance based dissimilarity index. We also test whether disturbance history or fertility influence the relationship between identity shifts and dominance structure. Results We found that the impact of disturbance on temporal turnover depends on soil fertility. The greatest turnover occurred in the most fertile forests immediately after disturbance. There, species gains and losses strongly altered dominance structure leading to high turnover, whereas undisturbed old forests and nutrient-poor habitats were characterized by stable dominant species even when the majority of species shifted their identity. Main conclusions Our results suggest that human impacts on temporal biodiversity change vary along environmental gradients. In boreal forests, the fertile habitats have a higher probability than nutrient-poor sites of changing their composition in response to anthropogenic disturbances. Resource availability and disturbance history may thus influence consequences of temporal turnover for ecosystem functioning.
  • Wang, Youshi; Yang, Zhiyong; Zhou, Shurong; Soininen, Janne; Ai, Dexiecuo; Li, Yali; Chu, Chengjin (2013)
  • Mateo, Ruben G.; Broennimann, Olivier; Normand, Signe; Petitpierre, Blaise; Araujo, Miguel B.; Svenning, Jens-C.; Baselga, Andres; Fernandez-Gonzalez, Federico; Gomez-Rubio, Virgilio; Munoz, Jesus; Suarez, Guillermo M.; Luoto, Miska; Guisan, Antoine; Vanderpoorten, Alain (2016)
    It remains hotly debated whether latitudinal diversity gradients are common across taxonomic groups and whether a single mechanism can explain such gradients. Investigating species richness (SR) patterns of European land plants, we determine whether SR increases with decreasing latitude, as predicted by theory, and whether the assembly mechanisms differ among taxonomic groups. SR increases towards the south in spermatophytes, but towards the north in ferns and bryophytes. SR patterns in spermatophytes are consistent with their patterns of beta diversity, with high levels of nestedness and turnover in the north and in the south, respectively, indicating species exclusion towards the north and increased opportunities for speciation in the south. Liverworts exhibit the highest levels of nestedness, suggesting that they represent the most sensitive group to the impact of past climate change. Nevertheless, although the extent of liverwort species turnover in the south is substantially and significantly lower than in spermatophytes, liverworts share with the latter a higher nestedness in the north and a higher turn-over in the south, in contrast to mosses and ferns. The extent to which the similarity in the patterns displayed by spermatophytes and liverworts reflects a similar assembly mechanism remains, however, to be demonstrated.
  • Thakur, Madhav P.; Phillips, Helen R. P.; Brose, Ulrich; De Vries, Franciska T.; Lavelle, Patrick; Loreau, Michel; Mathieu, Jerome; Mulder, Christian; Van der Putten, Wim H.; Rillig, Matthias C.; Wardle, David A.; Bach, Elizabeth M.; Bartz, Marie L. C.; Bennett, Joanne M.; Briones, Maria J. I.; Brown, George; Decaëns, Thibaud; Eisenhauer, Nico; Ferlian, Olga; Guerra, Carlos António; König-Ries, Birgitta; Orgiazzi, Alberto; Ramirez, Kelly S.; Russell, David J.; Rutgers, Michiel; Wall, Diana H.; Cameron, Erin K. (2020)
    Soil is one of the most biodiverse terrestrial habitats. Yet, we lack an integrative conceptual framework for understanding the patterns and mechanisms driving soil biodiversity. One of the underlying reasons for our poor understanding of soil biodiversity patterns relates to whether key biodiversity theories (historically developed for aboveground and aquatic organisms) are applicable to patterns of soil biodiversity. Here, we present a systematic literature review to investigate whether and how key biodiversity theories (species-energy relationship, theory of island biogeography, metacommunity theory, niche theory and neutral theory) can explain observed patterns of soil biodiversity. We then discuss two spatial compartments nested within soil at which biodiversity theories can be applied to acknowledge the scale-dependent nature of soil biodiversity.