scholarly journals Temporal changes in spatial variation: partitioning the extinction and colonisation components of beta diversity

2021 ◽  
Author(s):  
Shinichi Tatsumi ◽  
Ryosuke Iritani ◽  
Marc W. Cadotte
Keyword(s):  
Spatial Variation ◽  
Beta Diversity ◽  
Variation Partitioning ◽  
Temporal Changes

scholarly journals Partitioning the temporal changes in abundance-based beta diversity into loss and gain components

2021 ◽  
Author(s):  
Shinichi Tatsumi ◽  
Ryosuke Iritani ◽  
Marc W Cadotte
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Spatial Variation ◽  
Beta Diversity ◽  
Temporal Dynamics ◽  
Species Abundance ◽  
Temporal Changes ◽  
Ecological Communities ◽  
Multiple Site ◽  
Unified Approach

Spatial variation in species composition, or beta diversity, plays a central role in gauging the structure of ecological communities. Here, we develop a new numerical method to partition the impacts of abundance losses and gains on the temporal changes in spatial beta diversity. We show that the temporal changes in pairwise dissimilarity measures (Ruzka and Bray-Curtis indices) and a multiple-site measure (normalized Whittaker's beta) can be partitioned into six terms that reflect the losses and gains in species abundance. Our new method provides a unified approach to disentangle the temporal dynamics of spatial community structure by means of either incidence- or abundance-based data.

scholarly journals Degrees of compositional shift in tree communities vary along a gradient of temperature change rates over one decade: Application of an individual-based temporal beta-diversity concept

2020 ◽  
Author(s):  
Ryosuke Nakadai
Keyword(s):  
Temperature Change ◽  
Community Composition ◽  
Beta Diversity ◽  
Temporal Patterns ◽  
Diversity Indices ◽  
Temporal Changes ◽  
Individual Identity ◽  
Relative Speed ◽  
Identity Information ◽  
Temporal Beta Diversity

AbstractTemporal patterns in communities have gained widespread attention recently, to the extent that temporal changes in community composition are now termed “temporal beta-diversity”. Previous studies of beta-diversity have made use of two classes of dissimilarity indices: incidence-based (e.g., Sørensen and Jaccard dissimilarity) and abundance-based (e.g., Bray–Curtis and Ružička dissimilarity). However, in the context of temporal beta-diversity, the persistence of identical individuals and turnover among other individuals within the same species over time have not been considered, despite the fact that both will affect compositional changes in communities. To address this issue, I propose new index concepts for beta-diversity and the relative speed of compositional shifts in relation to individual turnover based on individual identity information. Individual-based beta-diversity indices are novel dissimilarity indices that consider individual identity information to quantitatively evaluate temporal change in individual turnover and community composition. I applied these new indices to individually tracked tree monitoring data in deciduous and evergreen broad-leaved forests across the Japanese archipelago with the objective of quantifying the effect of climate change trends (i.e., rates of change of both annual mean temperature and annual precipitation) on individual turnover and compositional shifts at each site. A new index explored the relative contributions of mortality and recruitment processes to temporal changes in community composition. Clear patterns emerged showing that an increase in the temperature change rate facilitated the relative contribution of mortality components. The relative speed of compositional shift increased with increasing temperature change rates in deciduous forests but decreased with increasing warming rates in evergreen forests. These new concepts provide a way to identify novel and high-resolution temporal patterns in communities.

scholarly journals Statistical methods for temporal and space–time analysis of community composition data

2014 ◽  
Vol 281 (1778) ◽  
pp. 20132728 ◽  
Author(s):  
Pierre Legendre ◽  
Olivier Gauthier
Keyword(s):  
Statistical Methods ◽  
Community Composition ◽  
Beta Diversity ◽  
Variation Partitioning ◽  
Regression Tree ◽  
Space Time ◽  
Time Variability ◽  
Ecological Data ◽  
Canonical Ordination ◽  
Temporal Beta Diversity

This review focuses on the analysis of temporal beta diversity, which is the variation in community composition along time in a study area. Temporal beta diversity is measured by the variance of the multivariate community composition time series and that variance can be partitioned using appropriate statistical methods. Some of these methods are classical, such as simple or canonical ordination, whereas others are recent, including the methods of temporal eigenfunction analysis developed for multiscale exploration (i.e. addressing several scales of variation) of univariate or multivariate response data, reviewed, to our knowledge for the first time in this review. These methods are illustrated with ecological data from 13 years of benthic surveys in Chesapeake Bay, USA. The following methods are applied to the Chesapeake data: distance-based Moran's eigenvector maps, asymmetric eigenvector maps, scalogram, variation partitioning, multivariate correlogram, multivariate regression tree, and two-way MANOVA to study temporal and space–time variability. Local (temporal) contributions to beta diversity (LCBD indices) are computed and analysed graphically and by regression against environmental variables, and the role of species in determining the LCBD values is analysed by correlation analysis. A tutorial detailing the analyses in the R language is provided in an appendix.

ANALYZING BETA DIVERSITY: PARTITIONING THE SPATIAL VARIATION OF COMMUNITY COMPOSITION DATA

2005 ◽  
Vol 75 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Pierre Legendre ◽  
Daniel Borcard ◽  
Pedro R. Peres-Neto
Keyword(s):  
Spatial Variation ◽  
Community Composition ◽  
Beta Diversity ◽  
Diversity Partitioning ◽  
Composition Data

scholarly journals Beta Diversity of Antarctic and Sub-Antarctic Benthic Communities Reveals a Major Role of Stochastic Assembly Processes

2021 ◽  
Vol 8 ◽  
Author(s):  
Nelson Valdivia ◽  
José Garcés-Vargas ◽  
Ignacio Garrido ◽  
Iván Gómez ◽  
Pirjo Huovinen ◽  
...  
Keyword(s):  
Stochastic Processes ◽  
Spatial Variation ◽  
Community Assembly ◽  
Beta Diversity ◽  
Seawater Temperature ◽  
Environmental Filtering ◽  
Ecological Processes ◽  
Mean Values ◽  
Sampling Protocols ◽  
Strait Of Magellan

Community assembly is the result of both, deterministic and stochastic processes. The former encompasses niche-based local-scale mechanisms such as environmental filtering and biotic interactions; the latter includes ecological drift, probabilistic colonisation, and random extinctions. Using standardised sampling protocols, we show that the spatial variation in species composition (beta diversity) of shallow subtidal macrobenthic communities of sub-Antarctic (Strait of Magellan and Yendegaia Fjord [Beagle Channel]) and Antarctic (Fildes Bay [King George Island, West Antarctic Peninsula]) localities reflects a high contribution of stochastic processes to community assembly. Null model analyses indicated that random sampling from species pools of different sizes drove the observed among-locality differences in incidence- and abundance-based beta diversity. We analysed a normalised stochasticity ratio (NST), which delimits between more deterministic (<50%) and more stochastic (>50%) assembly. NST was notably larger than 50%, with mean values of 69.5% (95% CI = 69.2–69.8%), 62.5% (62.1–62.9%), and 72.8% (72.5–73.2%) in Strait of Magellan, Yendegaia Fjord, and Fildes Bay, respectively. Accordingly, environmental factors, such as depth, seawater temperature, salinity, and underwater light penetration, accounted for a small fraction of the spatial variation in community composition across the three localities. In this region, therefore, stochastic processes could have stronger effects on community assembly than deterministic niche-based factors. As anthropogenic biotic homogenisation continues apace, our study can give useful insights into the major ecological processes in Southern Ocean’ coastal marine communities.

Benthic community history in the Changjiang (Yangtze River) mega-delta: Damming, urbanization, and environmental control

Paleobiology ◽  
2019 ◽  
Vol 45 (3) ◽  
pp. 469-483
Author(s):  
Richard Ching Wa Cheung ◽  
Moriaki Yasuhara ◽  
Hokuto Iwatani ◽  
Chih-Lin Wei ◽  
Yun-wei Dong
Keyword(s):  
Benthic Community ◽  
Bottom Water ◽  
Environmental Control ◽  
Anthropogenic Activities ◽  
Variation Partitioning ◽  
Population Expansion ◽  
Temporal Changes ◽  
Ecological Impacts ◽  
Ocean Currents ◽  
Bottom Water Temperature

AbstractThe coastal environment of the Changjiang delta has been influenced by recent anthropogenic activities such as dam construction and increased sewage and fertilizer inputs. Previous work examined the compositional shift of marine plankton to assess ecological impacts of these activities on marine ecosystems in the Changjiang discharge area. Here we used benthic marine ostracodes collected in the Changjiang estuary and the adjacent East China Sea in the 1980s and the 2010s, respectively, to investigate temporal changes of the benthic community and controlling factors for the benthic fauna. Our results revealed more shoreward distribution of some well-known offshore ostracode species in the 2010s compared with the 1980s and a relatively more important role for environmental processes (e.g., bottom-water temperature, bottom-water salinity, and eutrophic conditions of surface water) than spatial processes (e.g., the flow of ocean currents) in structuring ostracode compositions. The temporal changes in the ostracode community are likely attributable to the combined effects of reduced fresh water and sediment discharge and eutrophic conditions of the Changjiang due to the many dams constructed along the Changjiang and population expansion in the Changjiang Basin. Results of redundancy analysis and variation partitioning suggest that ocean currents facilitated environmental filtering of ostracode species such that they could disperse to preferred environmental conditions. These findings highlight the potential uses of marine microfossils to better understand ecological impacts on benthic ecosystems in vulnerable Asian mega-deltas and provide insights into the integration of metacommunity concepts in disentangling dynamics of marine benthic communities.

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