Author
Marta Rueda
Other affiliations: University of Alcalá, University of California, Irvine
Bio: Marta Rueda is an academic researcher from Spanish National Research Council. The author has contributed to research in topics: Species richness & Biodiversity. The author has an hindex of 17, co-authored 30 publications receiving 1004 citations. Previous affiliations of Marta Rueda include University of Alcalá & University of California, Irvine.
Papers
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Universidade Federal de Goiás1, Longwood University2, University of Connecticut3, University of Seville4, University of Alcalá5, Spanish National Research Council6, University of Basel7, National Scientific and Technical Research Council8, University of Mainz9, University of the Azores10, Autonomous University of Madrid11, Stellenbosch University12, University of Salamanca13, University of Nottingham14, University of California, Santa Barbara15, Imperial College London16, Earlham College17, University of Ottawa18, Natural History Museum19, Illinois State Museum20, University of Copenhagen21, University of Tennessee22, University of Bergen23, University of California, Irvine24
TL;DR: In this article, the authors analyzed the relationship between environmental predictors and the geographical distribution of species richness, body size, range size and abundance in 97 multi-factorial data sets and concluded that the ecological importance of regression coefficients cannot be evaluated with confidence irrespective of whether spatially explicit or non-spatial modeling is used.
Abstract: A major focus of geographical ecology and macroecology is to understand the causes of spatially structured ecological patterns. However, achieving this understanding can be complicated when using multiple regression, because the relative importance of explanatory variables, as measured by regression coefficients, can shift depending on whether spatially explicit or non-spatial modeling is used. However, the extent to which coefficients may shift and why shifts occur are unclear. Here, we analyze the relationship between environmental predictors and the geographical distribution of species richness, body size, range size and abundance in 97 multi-factorial data sets. Our goal was to compare standardized partial regression coefficients of non-spatial ordinary least squares regressions (i.e. models fitted using ordinary least squares without taking autocorrelation into account; "OLS models" hereafter) and eight spatial methods to evaluate the frequency of coefficient shifts and identify characteristics of data that might predict when shifts are likely. We generated three metrics of coefficient shifts and eight characteristics of the data sets as predictors of shifts. Typical of ecological data, spatial autocorrelation in the residuals of OLS models was found in most data sets. The spatial models varied in the extent to which they minimized residual spatial autocorrelation. Patterns of coefficient shifts also varied among methods and datasets, although the magnitudes of shifts tended to be small in all cases. We were unable to identify strong predictors of shifts, including the levels of autocorrelation in either explanatory variables or model residuals. Thus, changes in coefficients between spatial and non-spatial methods depend on the method used and are largely idiosyncratic, making it difficult to predict when or why shifts occur. We conclude that the ecological importance of regression coefficients cannot be evaluated with confidence irrespective of whether spatially explicit modelling is used or not. Researchers may have little choice but to be more explicit about the uncertainty of models and more cautious in their interpretation.
265 citations
TL;DR: Tropical niche conservatism in the face of long-term climate change, probably initiated in the Late Cretaceous associated with the rise of the Rocky Mountains, is a strong driver of the phylogenetic structure of the angiosperm component of forest communities across the USA.
Abstract: AimThe fossil record has led to a historical explanation for forest diversity gradients within the cool parts of the Northern Hemisphere, founded on a limited ability of woody angiosperm clades to adapt to mid-Tertiary cooling. We tested four predictions of how this should be manifested in the phylogenetic structure of 91,340 communities: (1) forests to the north should comprise species from younger clades (families) than forests to the south; (2) average cold tolerance at a local site should be associated with the mean family age (MFA) of species; (3) minimum temperature should account for MFA better than alternative environmental variables; and (4) traits associated with survival in cold climates should evolve under a niche conservatism constraint. LocationThe contiguous United States. MethodsWe extracted angiosperms from the US Forest Service's Forest Inventory and Analysis database. MFA was calculated by assigning age of the family to which each species belongs and averaging across the species in each community. We developed a phylogeny to identify phylogenetic signal in five traits: realized cold tolerance, seed size, seed dispersal mode, leaf phenology and height. Phylogenetic signal representation curves and phylogenetic generalized least squares were used to compare patterns of trait evolution against Brownian motion. Eleven predictors structured at broad or local scales were generated to explore relationships between environment and MFA using random forest and general linear models. ResultsConsistent with predictions, (1) southern communities comprise angiosperm species from older families than northern communities, (2) cold tolerance is the trait most strongly associated with local MFA, (3) minimum temperature in the coldest month is the environmental variable that best describes MFA, broad-scale variables being much stronger correlates than local-scale variables, and (4) the phylogenetic structures of cold tolerance and at least one other trait associated with survivorship in cold climates indicate niche conservatism. Main conclusionsTropical niche conservatism in the face of long-term climate change, probably initiated in the Late Cretaceous associated with the rise of the Rocky Mountains, is a strong driver of the phylogenetic structure of the angiosperm component of forest communities across the USA. However, local deterministic and/or stochastic processes account for perhaps a quarter of the variation in the MFA of local communities.
131 citations
University of North Carolina at Greensboro1, Colorado State University2, University of California, Santa Barbara3, New Mexico State University4, Johns Hopkins University5, University of New Mexico6, University of California, Davis7, Northeastern University8, University of the Witwatersrand9, Wake Forest University10, University of Agriculture, Faisalabad11, Hawassa University12, Indian Institute of Science13, Utah State University14, Montana State University15, United States Geological Survey16, University of Central Florida17, Archbold Biological Station18, International Trademark Association19, University of Buenos Aires20, Northwest A&F University21, University of Grenoble22, Office of Environment and Heritage23, University of New South Wales24, University of Texas at Austin25, University of La Laguna26, Thompson Rivers University27, Dalhousie University28, University of Wyoming29, University of Nebraska–Lincoln30, Nelson Mandela Metropolitan University31, University of Jyväskylä32, University of the Republic33, National Scientific and Technical Research Council34, La Trobe University35, University of Groningen36, University of Florida37, University of Alcalá38, The Nature Conservancy39, Swiss Federal Institute for Forest, Snow and Landscape Research40, Spanish National Research Council41, National Centre for Biological Sciences42, University of Leeds43, Yokohama National University44, Federation University Australia45, Technische Universität Darmstadt46, North-West University47, University of Wisconsin–Green Bay48, Agricultural Research Service49, Ghent University50, Kent State University51, Chinese Academy of Sciences52
TL;DR: It is shown that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of Herbivore effects on biodiversity in grassland and savannah sites.
Abstract: Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.
116 citations
Logan College of Chiropractic1, Utah State University2, University of Jena3, University of Tartu4, University of Osnabrück5, Spanish National Research Council6, University of California, Davis7, California State University, Stanislaus8, University of California, Berkeley9, University of Navarra10, University of Bayreuth11, Royal Liverpool and Broadgreen University Hospital NHS Trust12, James Hutton Institute13, University of Aberdeen14, University of the Basque Country15, University of Göttingen16, Academy of Sciences of the Czech Republic17, Sewanee: The University of the South18, University of South Bohemia in České Budějovice19, University of Groningen20, Bjerknes Centre for Climate Research21, Haukeland University Hospital22, Kent State University23, Massachusetts Institute of Technology24, Landcare Research25, Taizhou University26
TL;DR: Stability was associated more strongly with the degree of synchrony among dominant species than with species richness, which is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities.
Abstract: The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability.
90 citations
TL;DR: Using a recently developed quantitative method, the world's zoogeographical regions are evaluated following Alfred Russel Wallace's criteria as closely as possible.
Abstract: Aim
When dividing the world into zoogeographical regions, Alfred Russel Wallace stipulated a set of criteria by which regions should be determined, foremost the use of generic rather than species distributions. Yet, recent updates of Wallace's scheme have not followed his reasoning, probably explaining in part the discrepancies found. Using a recently developed quantitative method, we evaluated the world's zoogeographical regions following his criteria as closely as possible.
Location
Global.
Methods
We subjected presence–absence data from range maps of birds, mammals and amphibians to an innovative clustering algorithm, affinity propagation. We used genera as our taxonomic rank, although species and familial ranks were also assessed, to evaluate how divergence from Wallace's criteria influences the results. We also accepted Wallace's argument that bats and migratory birds should be excluded (although he was contradictory about the birds) and devised a procedure to determine the optimal number of regions to eliminate subjectivity in delimiting the number of regions.
Results
Regions attained using genera (eight for mammals and birds and six for amphibians) strongly coincided with the regions proposed by Wallace. The regions for amphibians were nearly identical to Wallace's scheme, whereas we obtained two new ‘regions’ for mammals and two for birds that largely coincide with Wallace's subregions. As argued by Wallace, there are strong reasons not to consider these as being equivalent to the six main regions. Species distributions generated many small regions related to contemporary climate and vegetation patterns, whereas at the familial rank regions were very broad. The differences between our generic maps and Wallace's all involve areas which he identified as being uncertain in his regionalization.
Main conclusions
Despite more than 135 years of additional knowledge of distributions, the shuffling of generic concepts, and the development of computers and complex analytical techniques, Wallace's zoogeographical regions appear to be no less valid than they were when he proposed them. Recent studies re-evaluating Wallace's scheme should not be considered updates as such because they have not followed Wallace's reasoning, and all computer-based analyses, including this one, are subject to the vagaries of the particular methods used.
87 citations
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
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TL;DR: The evidence suggests that of the various proposed dates two do appear to conform to the criteria to mark the beginning of the Anthropocene: 1610 and 1964.
Abstract: Time is divided by geologists according to marked shifts in Earth's state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Here we review the historical genesis of the idea and assess anthropogenic signatures in the geological record against the formal requirements for the recognition of a new epoch. The evidence suggests that of the various proposed dates two do appear to conform to the criteria to mark the beginning of the Anthropocene: 1610 and 1964. The formal establishment of an Anthropocene Epoch would mark a fundamental change in the relationship between humans and the Earth system.
1,173 citations
TL;DR: SAM (Spatial Analysis in Macroecology) as discussed by the authors ) is a freeware application that offers a comprehensive array of spatial statistical methods, focused primarily on surface pattern spatial analysis.
Abstract: SAM (Spatial Analysis in Macroecology) is a freeware application that offers a comprehensive array of spatial statistical methods, focused primarily on surface pattern spatial analysis. SAM is a compact, but powerful stand-alone software, with a user-friendly, menu-driven graphical interface. The methods available in SAM are the most commonly used in macroecology and geographical ecology, and range from simple tools for exploratory graphical analysis (e.g. mapping and graphing) and descriptive statistics of spatial patterns (e.g. autocorrelation metrics), to advanced spatial regression models (e.g. autoregression and eigenvector filtering). Download of the software, along with the user manual, can be downloaded online at the SAM website: (permanent URL at ).
1,123 citations