Spatial scaling of beta diversity in the shallow-marine fossil record

Paleobiology ◽  
2020 ◽  
pp. 1-15
Author(s):  
Tom M. Womack ◽  
James S. Crampton ◽  
Michael J. Hannah
Keyword(s):  
Beta Diversity ◽  
Fossil Record ◽  
Minimum Spanning Tree ◽  
Spatial Scales ◽  
Temporal Trends ◽  
Grid Cell ◽  
Ecological Communities ◽  
Spatial Scaling ◽  
Modern Biology ◽  
Shallow Marine

Abstract Beta diversity quantifies the spatial structuring of ecological communities and is a fundamental partition of biodiversity, central to understanding many macroecological phenomena in modern biology and paleobiology. Despite its common application in ecology, studies of beta diversity in the fossil record are relatively limited at regional spatial scales that are important for understanding macroevolutionary processes. The spatial scaling of beta diversity in the fossil record is poorly understood, but has significant implications due to temporal variation in the spatial distribution of fossil collections and the large spatiotemporal scales typically employed. Here we test the spatial scaling of several common measures of beta diversity using the Cenozoic shallow-marine molluscan fossil record of New Zealand and derive a spatially standardized time series of beta diversity. To measure spatial scaling, we use and compare grid-cell occupancy based on an equal-area grid and summed minimum spanning tree length, both based on reconstructed paleocoordinates of fossil collections. We find that beta diversity is spatially dependent at local to regional scales, regardless of the metric or spatial scaling utilized, and that spatial standardization significantly changes apparent temporal trends of beta diversity and, therefore, inferences about processes driving diversity change.

scholarly journals Long-term data reveal unimodal responses of ground beetle abundance to precipitation and land use but no changes in taxonomic and functional diversity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petr Zajicek ◽  
Ellen A. R. Welti ◽  
Nathan J. Baker ◽  
Kathrin Januschke ◽  
Oliver Brauner ◽  
...  
Keyword(s):  
Land Use ◽  
Functional Diversity ◽  
Spatial Scales ◽  
Ground Beetle ◽  
Temporal Trends ◽  
Ground Beetles ◽  
Community Change ◽  
Ecological Communities ◽  
Activity Density

AbstractWhile much of global biodiversity is undoubtedly under threat, the responses of ecological communities to changing climate, land use intensification, and long-term changes in both taxonomic and functional diversity over time, has still not been fully explored for many taxonomic groups, especially invertebrates. We compiled time series of ground beetles covering the past two decades from 40 sites located in five regions across Germany. We calculated site-based trends for 21 community metrics representing taxonomic and functional diversity of ground beetles, activity density (a proxy for abundance), and activity densities of functional groups. We assessed both overall and regional temporal trends and the influence of the global change drivers of temperature, precipitation, and land use on ground beetle communities. While we did not detect overall temporal changes in ground beetle taxonomic and functional diversity, taxonomic turnover changed within two regions, illustrating that community change at the local scale does not always correspond to patterns at broader spatial scales. Additionally, ground beetle activity density had a unimodal response to both annual precipitation and land use. Limited temporal change in ground beetle communities may indicate a shifting baseline, where community degradation was reached prior to the start of our observation in 1999. In addition, nonlinear responses of animal communities to environmental change present a challenge when quantifying temporal trends.

scholarly journals The geometry of the distance-decay of similarity in ecological communities

2017 ◽  
Author(s):  
Joshua Ladau ◽  
Jessica L. Green ◽  
Katherine S. Pollard
Keyword(s):  
Beta Diversity ◽  
Functional Form ◽  
Spatial Scales ◽  
Geometric Probability ◽  
Distance Decay ◽  
Quadratic Model ◽  
Ecological Communities ◽  
Tropical Vegetation ◽  
Effective Conservation ◽  
Distance Decay Of Similarity

AbstractUnderstanding beta-diversity has strong implications for evaluating the extent of biodiversity and formulating effective conservation policy. Here, we show that the distance-decay relationship, an important measure of beta-diversity, follows a universal form which we call the piecewise quadratic model. To derive the piecewise quadratic model, we develop a new conceptual framework which is based on geometric probability and several key insights about the roles of study design (e.g., plot dimensions and spatial distributions). We fit the piecewise quadratic model to six empirical distance-decay relationships, spanning a range of taxa and spatial scales, including surveys of tropical vegetation, mammals, and amphibians. We find that the model predicts the functional form of the relationships extremely well, with coefficients of determination in excess of 0.95. Moreover, the model predicts a phase transition at distance scales where sample plots are overlapping, which we confirm empirically. Our framework and model provide a fundamental, quantitative link between distance-decay relationships and the shapes of ranges of taxa.

scholarly journals Effects of primary productivity on beta diversity of ecological communities

2019 ◽  
Vol 31 ◽  
Author(s):  
Leticia Siman Bora ◽  
Juliana Wojciechowski ◽  
Jaqueline Dittrich ◽  
André Andrian Padial
Keyword(s):  
Primary Productivity ◽  
Beta Diversity ◽  
Spatial Scales ◽  
Small Body ◽  
Ecological Factors ◽  
Scientometric Analysis ◽  
Aquatic Environments ◽  
Ecological Communities ◽  
Terrestrial Environments ◽  
Negative Relationships

Abstract Aim Several ecological factors are predicted to affect beta diversity - the dissimilarity of communities among localities or through time. Considering the effect of primary productivity, there is a divergence in the literature concerning if it is positive, negative or hump-shaped. This is relevant considering the discussion on the role of primary productivity on deterministic and stochastic processes shaping ecological communities. The main goal of this study was to review ecological literature to explore causes for variation in the predominant relationship between beta diversity and primary productivity. Methods We have performed a scientometric analysis following the PRISMA statement for systematic reviews and the articles search was made through the ISI Web of Science® database. Results The number of articles approaching the relationship between beta diversity and primary productivity is growing more than expected by the natural growth in published articles. From the 465 articles found, only 38 directly dealt with beta diversity-productivity relationship. From them, we extracted 76 relationships, most of them positive, in almost all factors analyzed. Even so, the proportion of negative studies was higher in aquatic environments. In the Afrotropic region, only negative relationships in terrestrial studies were found. There is a clear inclination towards studies regarding large spatial scales, terrestrial environments, with vertebrates and in the Neartic or Paleartic regions. In aquatic environments there was a clear dominance of studies using small-body organisms, contrasting with terrestrial studies that used more often vertebrates and plants. Conclusions There is an increasing interest in studies concerning this relationship. Positive relations can be explained by several ecological factors, and the more common negative relationships in aquatic environments can be explained by the fact that productivity can cause eutrophication. We also pointed out gaps in the knowledge, especially considering studies in small and medium spatial scales, groups beyond plants and vertebrates in terrestrial environments, and aquatic studies in Afrotropic and Indo – Malaya regions.

scholarly journals Spatial scale-dependent land–atmospheric methane exchanges in the northern high latitudes from 1993 to 2004

2014 ◽  
Vol 11 (7) ◽  
pp. 1693-1704 ◽  
Author(s):  
X. Zhu ◽  
Q. Zhuang ◽  
X. Lu ◽  
L. Song
Keyword(s):  
Spatial Heterogeneity ◽  
Spatial Scale ◽  
Water Table ◽  
Spatial Scales ◽  
Grid Cell ◽  
High Latitudes ◽  
Atmospheric Methane ◽  
Ch4 Emissions ◽  
Biogeochemical Models ◽  
Macro Scale

Abstract. Effects of various spatial scales of water table dynamics on land–atmospheric methane (CH4) exchanges have not yet been assessed for large regions. Here we used a coupled hydrology–biogeochemistry model to quantify daily CH4 exchanges over the pan-Arctic from 1993 to 2004 at two spatial scales of 100 km and 5 km. The effects of sub-grid spatial variability of the water table depth (WTD) on CH4 emissions were examined with a TOPMODEL-based parameterization scheme for the northern high latitudes. We found that both WTD and CH4 emissions are better simulated at a 5 km spatial resolution. By considering the spatial heterogeneity of WTD, net regional CH4 emissions at a 5 km resolution are 38.1–55.4 Tg CH4 yr−1 from 1993 to 2004, which are on average 42% larger than those simulated at a 100 km resolution using a grid-cell-mean WTD scheme. The difference in annual CH4 emissions is attributed to the increased emitting area and enhanced flux density with finer resolution for WTD. Further, the inclusion of sub-grid WTD spatial heterogeneity also influences the inter-annual variability of CH4 emissions. Soil temperature plays an important role in the 100 km estimates, while the 5 km estimates are mainly influenced by WTD. This study suggests that previous macro-scale biogeochemical models using a grid-cell-mean WTD scheme might have underestimated the regional CH4 emissions. The spatial scale-dependent effects of WTD should be considered in future quantification of regional CH4 emissions.

scholarly journals Unimodal Relationships of Understory Alpha and Beta Diversity along Chronosequence in Coppiced and Unmanaged Beech Forests

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 101 ◽  
Author(s):  
Sándor Bartha ◽  
Roberto Canullo ◽  
Stefano Chelli ◽  
Giandiego Campetella
Keyword(s):  
Beta Diversity ◽  
Management Practices ◽  
Multiple Scales ◽  
Forest Succession ◽  
Spatial Scales ◽  
Alpha Diversity ◽  
Structural Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Coppice Management

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value.

Trace Fossils in Quaternary, Bahamian-Style Carbonate Environments: The Modern to Fossil Transition

1992 ◽  
Vol 5 ◽  
pp. 105-120 ◽  
Author(s):  
H. Allen Curran
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
Subtidal Zone ◽  
Carbonate Sediments ◽  
Shallow Marine ◽  
Shallow Subtidal ◽  
Dominant Process ◽  
Burrowing Activity

Tracemaking organisms are common and diverse components of the fauna and flora of tropical, shallow-marine and coastal carbonate environments. In the shallow subtidal zone, the burrowing activity of callianassid shrimp commonly is the dominant process in the modification of original depositional fabrics (Tudhope and Scoffin, 1984; Tedesco and Wanless, 1991). Both borers and burrowers have great potential to leave their mark in tropical carbonate sediments and rocks and to become part of the fossil record.

scholarly journals Scale-Optimized Surface Roughness for Topographic Analysis

Geosciences ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 322 ◽  
Author(s):  
John B. Lindsay ◽  
Daniel R. Newman ◽  
Anthony Francioni
Keyword(s):  
Surface Roughness ◽  
Forest Cover ◽  
Agricultural Land ◽  
Spatial Scales ◽  
Grid Cell ◽  
Topographic Analysis ◽  
Digital Elevation ◽  
Locally Adaptive ◽  
Elevation Model

Surface roughness is a terrain parameter that has been widely applied to the study of geomorphological processes. One of the main challenges in studying roughness is its highly scale-dependent nature. Determining appropriate mapping scales in topographically heterogenous landscapes can be difficult. A method is presented for estimating multiscale surface roughness based on the standard deviation of surface normals. This method utilizes scale partitioning and integral image processing to isolate scales of surface complexity. The computational efficiency of the method enables high scale sampling density and identification of maximum roughness for each grid cell in a digital elevation model (DEM). The approach was applied to a 0.5 m resolution LiDAR DEM of a 210 km2 area near Brantford, Canada. The case study demonstrated substantial heterogeneity in roughness properties. At shorter scales, tillage patterns and other micro-topography associated with ground beneath forest cover dominated roughness scale signatures. Extensive agricultural land-use resulted in 35.6% of the site exhibiting maximum roughness at micro-topographic scales. At larger spatial scales, rolling morainal topography and fluvial landforms, including incised channels and meander cut banks, were associated with maximum surface roughness. This method allowed for roughness mapping at spatial scales that are locally adapted to the topographic context of each individual grid cell within a DEM. Furthermore, the analysis revealed significant differences in roughness characteristics among soil texture categories, demonstrating the practical utility of locally adaptive, scale-optimized roughness.

scholarly journals Boreal river impoundments caused nearshore fish community assemblage shifts but little change in diversity: a multiscale analysis

2019 ◽  
Vol 76 (5) ◽  
pp. 740-752 ◽  
Author(s):  
Katrine Turgeon ◽  
Christian Turpin ◽  
Irene Gregory-Eaves
Keyword(s):  
Fish Community ◽  
River Flow ◽  
Spatial Scales ◽  
Temporal Trends ◽  
Ecosystem Functions ◽  
Anthropogenic Factors ◽  
Multiscale Approach ◽  
Sampling Station ◽  
Community Assemblage ◽  
Boreal River

River flow regulation, fragmentation, and changes in water quality caused by dams have varying effects on aquatic biodiversity and ecosystem functions, but are not clearly resolved in boreal ecosystems. We adopted a multiscale approach to quantify fish community trajectories over 20 years using a network of sites spread across four reservoirs in two hydroelectricity complexes in northern Quebec, where other anthropogenic factors have been negligible. Across three spatial scales, we found little evidence of directional temporal trends in diversity relative to reference sites. Using beta-diversity analyses, we also detected a high degree of stability in fish composition over time and space at the complex and reservoir scales. However, changes in species assemblage following impoundment were detected at the scale of the sampling station. At this scale, we found that some species consistently benefited (coregonids and pikes) from impoundment, whereas others were detrimentally affected (suckers and one salmonid). Overall, we conclude that examining different scales is key when trying to understand the impacts of humans on biodiversity and in formulating management recommendations.

scholarly journals Interpolation of LES Cloud Surfaces for Use in Direct Calculations of Entrainment and Detrainment

2011 ◽  
Vol 139 (2) ◽  
pp. 444-456 ◽  
Author(s):  
Jordan T. Dawe ◽  
Philip H. Austin
Keyword(s):  
Numerical Model ◽  
Spatial Scales ◽  
Grid Cell ◽  
Time Step ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Temporal And Spatial ◽  
Les Model ◽  
Direct Calculations ◽  
Good Agreement

Abstract Direct calculations of the entrainment and detrainment of air into and out of clouds require knowledge of the relative velocity difference between the air and the cloud surface. However, a discrete numerical model grid forces the distance moved by a cloud surface over a time step to be either zero or the width of a model grid cell. Here a method for the subgrid interpolation of a cloud surface on a discrete numerical model grid is presented. This method is used to calculate entrainment and detrainment rates for a large-eddy simulation (LES) model, which are compared with rates calculated via the direct flux method of Romps. The comparison shows good agreement between the two methods as long as the model clouds are well resolved by the model grid spacing. This limitation of this technique is offset by the ability to resolve fluxes on much finer temporal and spatial scales, making it suitable for calculating entrainment and detrainment profiles for individual clouds.

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