Community ecology in 3D: Tensor decomposition reveals spatio-temporal dynamics of large ecological communities

Frelat, Romain; Lindegren, Martin; Dencker, Tim Spaanheden; Floeter, Jens; Fock, Heino O.; Sguotti, Camilla; Stäbler, Moritz; Otto, Saskia A.; Möllmann, Christian

doi:10.1371/journal.pone.0188205

Cited by 23 publications

(19 citation statements)

References 51 publications

(61 reference statements)

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“…To our knowledge, this is the first study comparing long‐term trends and multi‐decadal dynamics in multiple dimensions of functional community change across trophic groups and areas. Previous trait‐based studies on long‐term functional community change have focused on single organism groups separately, either zoobenthos (Gogina, Darr, & Zettler, ; Neumann & Kröncke, ; Veríssimo et al, ; Weigel, Blenckner, & Bonsdorff, ) or fish (Baptista, Martinho, Nyjtrai, Pardal, & Dolbeth, ; Barcelo, Ciannelli, Olsen, Johannessen, & Knutsen, ; Dencker et al, ; Frelat et al, ), and particularly multi‐trait compositional changes on local scale (Clare, Robinson, & Frid, ; Frid & Caswell, ).…”

Section: Discussionmentioning

confidence: 99%

Four decades of functional community change reveals gradual trends and low interlinkage across trophic groups in a large marine ecosystem

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Olsson

et al. 2019

Global Change Biology

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The rate at which biological diversity is altered on both land and in the sea, makes temporal community development a critical and fundamental part of understanding global change. With advancements in trait‐based approaches, the focus on the impact of temporal change has shifted towards its potential effects on the functioning of the ecosystems. Our mechanistic understanding of and ability to predict community change is still impeded by the lack of knowledge in long‐term functional dynamics that span several trophic levels. To address this, we assessed species richness and multiple dimensions of functional diversity and dynamics of two interacting key organism groups in the marine food web: fish and zoobenthos. We utilized unique time series‐data spanning four decades, from three environmentally distinct coastal areas in the Baltic Sea, and assembled trait information on six traits per organism group covering aspects of feeding, living habit, reproduction and life history. We identified gradual long‐term trends, rather than abrupt changes in functional diversity (trait richness, evenness, dispersion) trait turnover, and overall multi‐trait community composition. The linkage between fish and zoobenthic functional community change, in terms of correlation in long‐term trends, was weak, with timing of changes being area and trophic group specific. Developments of fish and zoobenthos traits, particularly size (increase in small size for both groups) and feeding habits (e.g. increase in generalist feeding for fish and scavenging or predation for zoobenthos), suggest changes in trophic pathways. We summarize our findings by highlighting three key aspects for understanding functional change across trophic groups: (a) decoupling of species from trait richness, (b) decoupling of richness from density and (c) determining of turnover and multi‐trait dynamics. We therefore argue for quantifying change in multiple functional measures to help assessments of biodiversity change move beyond taxonomy and single trophic groups.

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Section: Discussionmentioning

confidence: 99%

Four decades of functional community change reveals gradual trends and low interlinkage across trophic groups in a large marine ecosystem

Törnroos

Pécuchet

Olsson

et al. 2019

Global Change Biology

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“…However, all three methods need to choose in advance the number of rank-1 tensors in their optimisation and obtain decompositions that are not nested as with SVD, in which the rank p approximation of X contains the approximation obtained for p (with p > p ). This property is often desirable for environmental data analysis (Frelat et al, 2017), as decomposition of the variance or sum of squares has a practical interpretation.…”

Section: Land Surface Model and Data Descriptionmentioning

confidence: 99%

Spatio-Temporal Variations and Uncertainty in Land Surface Modelling for High Latitudes: Univariate Response Analysis

Leibovici¹,

Quegan²,

Comyn‐Platt³

et al. 2019

Preprint

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<p><strong>Abstract.</strong> A range of applications analysing the impact of environmental changes due to climate change, e.g. geographical spread of climate sensitive infections (CSIs), agriculture crop modelling, etc., make use of Land Surface Modelling (LSM) to predict future land surface conditions. There are multiple LSMs to choose from that account for land processes in different ways and, depending on the application, the choice of LSM and its sensitivity will have different impacts. For useful predictions for a specific application, one must therefore understand the inherent uncertainties in the LSMs and the variations between them, as well as uncertainties arising from variation in the climate data driving the LSMs. This requires methods to analyse multivariate spatio-temporal variations and differences. A methodology is proposed based on multi-way data analysis, which extends Singular Value Decomposition (SVD) to multi-dimensional tables, and provides spatio-temporal descriptions of agreements and disagreements between LSMs for both historical simulations and future predictions. The application underlying this paper is prediction of how climate change will affect the spread of CSIs in the Fenno-Scandinavian and north-west Russian regions, and the approach is explored by comparing Net Primary Production (NPP) estimates over the period 1998&#8211;2013 from versions of leading LSMs (JULES, CLM5 and two versions of ORCHIDEE) that are adapted to high latitude processes, as well as variations in JULES up to 2100 when driven by 34 global circulation models (GCMs). A single optimal spatio-temporal pattern, with slightly different weights for the four LSMs (up to 14&#8201;% maximum difference), provides a good approximation to all their estimates of NPP, capturing between 87&#8201;% and 93&#8201;% of the variability in the individual models, as well as around 90&#8201;% of the variability in the combined LSM dataset. The next best adjustment to this pattern, capturing an extra 4&#8201;% of the overall variability, is essentially a spatial correction applied to ORCHIDEE-HLveg that significantly improves the fit to this LSM, with only small improvements for the other LSMs. Subsequent correction terms gradually improve the overall and individual LSM fits, but capture at most 1.7&#8201;% of the overall variability. Analysis of differences between LSMs provides information on the times and places where the LSMs differ and by how much, but in this case no single spatio-temporal pattern strongly dominates the variability. Hence interpretation of the analysis requires the summation of several such patterns. Nonetheless, the three best principal tensors capture around 76&#8201;% of the variability in the LSM differences, and to a first approximation successively indicate the times and places where ORCHIDEE-HLveg, CLM5 and ORCHIDEE-MICT respectively differ from the other LSMs. Differences between the climate forcing GCMs had a marginal effect up to 6&#8201;% on NPP predictions out to 2100 without specific spatio-temporal GCM interaction.</p>

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“…The boxes highlighted in red represent the part of the community that was analyzed in this study. species and influence the composition and dynamics of different pelagic and benthic communities (Beaugrand et al 2001, Reiss et al 2010, Frelat et al 2017. The North Sea is also characterized by strong anthropogenic impacts arising from multiple activities such as run-off from agriculture, oil extraction, shipping, and fishing.…”

Section: Study Areamentioning

confidence: 99%

Spatial distribution of life‐history traits and their response to environmental gradients across multiple marine taxa

et al. 2018

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Trait-based approaches enable comparison of community composition across multiple organism groups. Yet, little is known about the degree to which empirical trait responses found for one taxonomic group can be generalized across organisms. In this study, we investigated the spatial variability of marine community-weighted mean traits and compared their environmental responses across multiple taxa and habitats, including pelagic zooplankton (copepods), demersal fish, and benthic infaunal invertebrates. We used extensive, spatially explicit datasets collected from scientific surveys in the North Sea and examined community composition of these groups using a trait-based approach. In order to cover the key biological characteristics of an organism, we considered three life-history traits (adult size, offspring size, and fecundity) and taxon-specific feeding traits. While many of the traits co-varied in space and notably demonstrated a south-north gradient, none of the traits showed a consistent spatial distribution across all groups. However, traits are often correlated as a result of trade-offs. When studying spatial patterns of multiple traits variability in fish and copepods, we showed a high spatial correlation. This also applied to a lesser extent to fish and benthic infauna, whereas no correlation was found between benthic infauna and copepods. The result suggested a decoupling in the community traits between strictly benthic and strictly pelagic species. The strongest drivers of spatial variability for many community traits are the gradients in temperature seasonality, primary productivity, fishing effort, and depth. Spatial variability in benthic traits also co-varied with descriptors of the seabed habitat. Overall, results showed that trait responses to environmental gradients cannot be generalized across organism groups, pointing toward potential complex responses of multi-taxa communities to environmental changes and highlighting the need for cross-habitat multi-trait analyses to foresee how environmental change will affect community structure and biodiversity at large.

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Community ecology in 3D: Tensor decomposition reveals spatio-temporal dynamics of large ecological communities

Cited by 23 publications

References 51 publications

Four decades of functional community change reveals gradual trends and low interlinkage across trophic groups in a large marine ecosystem

Four decades of functional community change reveals gradual trends and low interlinkage across trophic groups in a large marine ecosystem

Spatio-Temporal Variations and Uncertainty in Land Surface Modelling for High Latitudes: Univariate Response Analysis

Spatial distribution of life‐history traits and their response to environmental gradients across multiple marine taxa

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