| 1. |
- Alves-Martins, Fernanda, et al.
(författare)
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Drivers of regional and local diversity of Amazonian stream Odonata
- 2019
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Ingår i: Insect Conservation and Diversity. - : Wiley-Blackwell. - 1752-458X .- 1752-4598. ; 12:3, s. 251-261
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Tidskriftsartikel (refereegranskat)abstract
- Large Amazonian rivers may act as dispersal barriers for animals with low dispersal abilities, limiting their distribution to certain interfluves. Consequently, the distribution of these taxa would be less affected by macroclimatic gradients. Conversely, high-dispersal taxa would be less constrained by large rivers and may track suitable climates. We evaluate whether Zygoptera and Anisoptera, two Odonata suborders with different dispersal abilities, show differences in distribution patterns across Amazonian interfluves. We further assess the relative importance of macroclimatic and habitat factors in their community assembly. We used network modularity analyses to identify biogeographic species pools and spatial buffers to define metacommunity species pools. Then, we used structural equationmodels to estimate the relative importance of multi-scale factors on species richness patterns. Zygoptera communities are more similar in species composition within than between interfluves, suggesting that large Amazonian rivers indeed limit the distribution of Zygoptera species. Conversely, the distribution of Anisoptera extends across Amazonian interfluves. Seasonality has a strong positive effect on Zygoptera and Anisoptera richness across scales. In addition, habitat integrity is negatively correlated with the regional species richness and abundance of Anisoptera and positively correlated with Zygoptera local richness. The contrasting effects of habitat integrity on Anisoptera and Zygoptera suggest that the former is favored in open habitats, whereas the latter is so in forests. Despite these differences, both suborders appear to follow similar community assembly mechanisms in Amazonia, with a strong climatic control across scales and an effect of habitat filters on local communities.
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| 2. |
- Calatayud, Joaquín, et al.
(författare)
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Pleistocene climate change and the formation of regional species pools
- 2019
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society Publishing. - 0962-8452 .- 1471-2954. ; 286:1905
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Tidskriftsartikel (refereegranskat)abstract
- Although the description of bioregions dates back to the origin of biogeography, the processes originating their associated species pools hive been seldom studied. Ancient historical events are thought to play a fundamental role in configuring bioregions, but the effects of more recent events on these regional biotas are largely unknown. We used a network approach to identify regional and sub-regional faunas of European Carabus beetles and developed a method to explore the relative contribution of dispersal barriers, niche similarities and phylogenetic history on their configuration. We identify a transition zone matching the limit of the ice sheets at the Last Glacial Maximum. While southern species pools are mostly separated by dispersal barriers, in the north species are mainly sorted by their environmental niches. Strikingly, most phylogenetic structuration of Carabus faunas occurred during the Pleistocene. Our results show how extreme recent historical events - such as Pleistocene climate cooling, rather than just deep-time evolutionary processes-can profoundly modify the composition and structure of geographical species pools.
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| 3. |
- Freitas, Tiago Magalhaes da Silva, et al.
(författare)
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Quantifying shortfalls in the knowledge on Neotropical Auchenipteridae fishes
- 2021
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Ingår i: Fish and Fisheries. - : John Wiley & Sons. - 1467-2960 .- 1467-2979. ; 22:1, s. 87-104
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Tidskriftsartikel (refereegranskat)abstract
- The Neotropics harbour the greatest diversity of freshwater fish on Earth. Despite recent advances in characterizing the fish fauna, the total number of species, distributional range, evolution and ecological traits remain uncertain. Thus, we quantify shortfalls in the knowledge of taxonomy (Linnean shortfall), geographic distribution (Wallacean shortfall), evolutionary relationships (Darwinian shortfall) and feeding habits (Raunki AE ran shortfall) of Auchenipteridae driftwood catfishes, one of the most representative groups of the Siluriformes family in the Neotropics. We find a steep increase in the historical accumulation of valid species over time, suggesting that 45% of the total number predicted remains to be described. Auchenipterids also remain under-collected; only 45% of the ecoregions and less than 3% of the one-degree grid cells covering the Neotropics are reasonably sampled. The topologies of recent phylogenies are more similar to each other than former ones, showing a tendency towards a robust phylogenetic hypothesis for this family. Current knowledge on feeding habits is biased towards a few genera and species and is still expanding with every new published study. Our study highlights specific knowledge gaps that need to be addressed: a considerable number of Auchenipteridae species remain to be described; and most of valid species lack reliable information on their geographic distribution and feeding habitat. It implies that research on fish systematic biology needs to advance and it will require a concerted effort of taxonomists, ecologists and biogeographers to reduce these gaps.
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| 4. |
- Hortal, Joaquin, et al.
(författare)
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Perspectives on the use of lakes and ponds as model systems for macroecological research
- 2014
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Ingår i: Journal of limnology. - : Pagepress. - 1129-5767 .- 1723-8633. ; 73:Suppl. 1, s. 46-60
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Tidskriftsartikel (refereegranskat)abstract
- Macroecology studies large-scale patterns aiming to identify the effects of general ecological processes. Although lakes (and ponds) are particularly suited for macroecological research due to their discrete nature and non geographically-structured variability, the development of this discipline in lentic habitats is comparatively much smaller than for terrestrial environments. This is despite the interest of limnologists for large-scale phenomena, which results in the high level of development of some disciplines such as predictive limnology. Here we discuss how current state-of-the-art in macroecology may benefit from research in lentic habitats at five topics. First, by including an island biogeography analytical framework to incorporate the effects of lake origin and history on lentic biodiversity. Second, by studying local and regional effects on the latitudinal gradients of species richness. Third, by considering lakes and ponds altogether for the study of beta diversity and metacommunity structure, which is already common ground in limnological research. Fourth, by relating species traits with ecosystem structure and functioning; here we consider in particular the potential effects of body size-determined dispersal and competitive exclusion processes on lake-wide trophic organization. And fifth, by incorporating current research in functional (i.e., trait) and phylogenetic diversity to the study of community structure. We finally conclude that lentic habitats can be particularly important for the development of the most functional aspects of macroecology, due to the relative ease of studying the different biotic and abiotic components of the system separately, compared to most terrestrial systems. This can allow teasing apart many of the confounding factors that are characteristic of macroecological research, thus helping the development of future theoretical syntheses.
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| 5. |
- Ari Noriega, Jorge, et al.
(författare)
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Does ecotourism impact biodiversity? : An assessment using dung beetles (Coleoptera: Scarabaeinae) as bioindicators in a tropical dry forest natural park
- 2020
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Ingår i: Ecological Indicators. - : Elsevier. - 1470-160X .- 1872-7034. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- Ecotourism can be defined as an environmental activity that takes place in well-preserved areas for recreation and with the responsibility of promoting their conservation. Nowadays, ecotourism is seen as a friendly pastime, but it can potentially affect negatively community diversity and structure by a number of processes such as soil compaction, erosion, and habitat alteration, among many others. Nonetheless, there is hardly any information on the impact of ecotourism in the Tropical Dry Forests and protected areas of the Neotropical region. In an attempt to fill this knowledge gap, the effect of ecotourism was evaluated in a study of a Tropical Dry Forest in the Tayrona National Natural Park of Colombia using dung beetles as bioindicators. A large-scale sampling of three sites with different levels of tourism intensity (no tourism - NT, low tourism - LT, and high tourism - HT) was performed using pitfall tramps baited with human/pig dung during two climatic seasons (rainy and dry). A total of 3238 individuals belonging to nine genera and 15 species were collected. Significant differences in abun-dances, richness, and the Shannon Wiener diversity index were observed between areas with tourism and those without. These differences disappeared during the dry season in response to the strong reduction in species abundance and richness associated to that time of year. All areas maintained a homogeneous beetle structure in terms of functional groups present irrelevant of the intensity level of tourism. Beta diversity analysis shows that the dung beetle assemblage has a nested structure, indicating that the pressure exerted by tourism entails the loss of particular species. Our results advocate that it is necessary to implement conservation strategies in order to reduce the negative impact of tourism on the National Park's biodiversity.
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| 6. |
- Bernardo-Madrid, R., et al.
(författare)
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Human activity is altering the world's zoogeographical regions
- 2019
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 22:8, s. 1297-1305
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Tidskriftsartikel (refereegranskat)abstract
- Zoogeographical regions, or zooregions, are areas of the Earth defined by species pools that reflect ecological, historical and evolutionary processes acting over millions of years. Consequently, researchers have assumed that zooregions are robust and unlikely to change on a human timescale. However, the increasing number of human-mediated introductions and extinctions can challenge this assumption. By delineating zooregions with a network-based algorithm, here we show that introductions and extinctions are altering the zooregions we know today. Introductions are homogenising the Eurasian and African mammal zooregions and also triggering less intuitive effects in birds and amphibians, such as dividing and redefining zooregions representing the Old and New World. Furthermore, these Old and New World amphibian zooregions are no longer detected when considering introductions plus extinctions of the most threatened species. Our findings highlight the profound and far-reaching impact of human activity and call for identifying and protecting the uniqueness of biotic assemblages.
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| 7. |
- Calatayud, Joaquín, et al.
(författare)
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Exploring the solution landscape enables more reliable network community detection
- 2019
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Ingår i: Physical review. E. - 2470-0045 .- 2470-0053. ; 100:5
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Tidskriftsartikel (refereegranskat)abstract
- To understand how a complex system is organized and functions, researchers often identify communities in the system's network of interactions. Because it is practically impossible to explore all solutions to guarantee the best one, many community-detection algorithms rely on multiple stochastic searches. But for a given combination of network and stochastic algorithms, how many searches are sufficient to find a solution that is good enough? The standard approach is to pick a reasonably large number of searches and select the network partition with the highest quality or derive a consensus solution based on all network partitions. However, if different partitions have similar qualities such that the solution landscape is degenerate, the single best partition may miss relevant information, and a consensus solution may blur complementary communities. Here we address this degeneracy problem with coarse-grained descriptions of the solution landscape. We cluster network partitions based on their similarity and suggest an approach to determine the minimum number of searches required to describe the solution landscape adequately. To make good use of all partitions, we also propose different ways to explore the solution landscape, including a significance clustering procedure. We test these approaches on synthetic networks and a real-world network using two contrasting community-detection algorithms: The algorithm that can identify more general structures requires more searches, and networks with clearer community structures require fewer searches. We also find that exploring the coarse-grained solution landscape can reveal complementary solutions and enable more reliable community detection.
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| 8. |
- Calatayud, Joaquín, et al.
(författare)
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Positive associations among rare species and their persistence in ecological assemblages
- 2020
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Ingår i: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 4:1, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- According to the competitive exclusion principle, species with low competitive abilities should be excluded by more efficient competitors; yet, they generally remain as rare species. Here, we describe the positive and negative spatial association networks of 326 disparate assemblages, showing a general organization pattern that simultaneously supports the primacy of competition and the persistence of rare species. Abundant species monopolize negative associations in about 90% of the assemblages. On the other hand, rare species are mostly involved in positive associations, forming small network modules. Simulations suggest that positive interactions among rare species and microhabitat preferences are the most probable mechanisms underpinning this pattern and rare species persistence. The consistent results across taxa and geography suggest a general explanation for the maintenance of biodiversity in competitive environments. Analysing spatial association networks among >300 terrestrial and aquatic assemblages, the authors find that the majority of negative associations involve abundant species. In contrast, rare species form mostly positive associations, potentially explaining their persistence in natural communities.
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| 9. |
- Calatayud, Joaquín, et al.
(författare)
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Regularities in species’ niches reveal the world’s climate regions
- 2021
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd.. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Climate regions form the basis of many ecological, evolutionary, and conservation studies. However, our understanding of climate regions is limited to how they shape vegetation: They do not account for the distribution of animals. Here we develop a network-based framework to identify important climates worldwide based on regularities in realized niches of about 26,000 tetrapods. We show that high-energy climates, including deserts, tropical savannas, and steppes, are consistent across animal-and plant-derived classifications, indicating similar underlying climatic determinants. Conversely, temperate climates differ across all groups, suggesting that these climates allow for idiosyncratic adaptations. Finally, we show how the integration of niche classifications with geographical information enables the detection of climatic transition zones and the signal of geographic and historical processes. Our results identify the climates shaping the distribution of tetrapods and call for caution when using general climate classifications to study the ecology, evolution, or conservation of specific taxa.
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| 10. |
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