Temporally robust spatial structure in ecosystems explained by local biodiversity regulation

The distribution in species' site occupancy is a fundamental pattern in spatial ecology. Despite decades of research, the mechanisms responsible for the shape of the distribution remain incompletely understood. Here, we simultaneously examining both spatial and temporal patterns of site occupancy in communities of macroinverterbrates, macrophytes and diatoms. We show that a simple patch dynamics model explains both the spatial structure and temporal dynamics in English rivers. The key mechanism responsible for the emergent spatial structure in the model are intrinsic regulation of biodiversity at the local scale which, when combined with inter-site dispersal and regional-scale invasion, drives local colonisation and extinction. Our analysis supports the notion that metacommunities exist in a kind of dynamic steady state arising from local ecological constraints and that this intrinsic regulation can drives the emergence of a wide variety of macroecological patterns.

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Large-scale frequency dynamics of alternative male phenotypes in natural populations of coho salmon (Oncorhynchus kisutch): patterns, processes, and implications

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-046 ◽

2007 ◽

Vol 64 (4) ◽

pp. 743-753 ◽

Cited By ~ 9

Author(s):

Yusuke Koseki ◽

Ian A Fleming

Keyword(s):

Large Scale ◽

Temporal Dynamics ◽

Coho Salmon ◽

Regional Scale ◽

Natural Populations ◽

Oncorhynchus Kisutch ◽

Population Variation ◽

Spatial And Temporal Patterns ◽

Fitness Functions ◽

Alternative Phenotypes

Using over 20 years of annual spawner survey data collected from 46 natural populations of coastal Oregon coho salmon (Oncorhynchus kisutch), we examined large-scale spatial and temporal dynamics of alternative male pheno types (age-3 hooknoses and age-2 jacks). Fluctuations in jack and hooknose abundance were synchronous among populations (i.e., region-wide synchrony), similar to patterns seen previously in Oregon hatchery populations and indicative of oceanic processes operating at large spatial and temporal scales. By contrast, regional-scale synchrony in the ratio of jack to hooknose males was likely attributable to the influences of the freshwater environment. Moreover, within-population variation in phenotype ratio was lower by brood year than by return year (i.e., weak cohort relationship), contrary to previous patterns in hatchery populations. The spatial and temporal patterns of phenotype ratio observed in natural populations but not in hatchery populations, where freshwater effects were statistically controlled, indicate that the frequency dynamics of coho male alternative phenotypes are influenced more strongly by freshwater than by marine processes. The environmentally induced variability in phenotype ratio suggests that there may be constant perturbations of fitness functions for alternative phenotypes, such that the system should be less stable than predicted from the status-dependent selection model with fixed fitness functions.

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Investigating the Spatio-Temporal Variation of Soil Moisture and Agricultural Drought towards Supporting Water Resources Management in the Red River Basin of Vietnam

Sustainability ◽

10.3390/su13094926 ◽

2021 ◽

Vol 13 (9) ◽

pp. 4926

Author(s):

Nguyen Duc Luong ◽

Nguyen Hoang Hiep ◽

Thi Hieu Bui

Keyword(s):

Soil Moisture ◽

River Basin ◽

Temporal Dynamics ◽

Regional Scale ◽

Dry Season ◽

Red River ◽

Agricultural Drought ◽

Severe Drought ◽

Red River Basin ◽

Spatio Temporal

The increasing serious droughts recently might have significant impacts on socioeconomic development in the Red River basin (RRB). This study applied the variable infiltration capacity (VIC) model to investigate spatio-temporal dynamics of soil moisture in the northeast, northwest, and Red River Delta (RRD) regions of the RRB part belongs to territory of Vietnam. The soil moisture dataset simulated for 10 years (2005–2014) was utilized to establish the soil moisture anomaly percentage index (SMAPI) for assessing intensity of agricultural drought. Soil moisture appeared to co-vary with precipitation, air temperature, evapotranspiration, and various features of land cover, topography, and soil type in three regions of the RRB. SMAPI analysis revealed that more areas in the northeast experienced severe droughts compared to those in other regions, especially in the dry season and transitional months. Meanwhile, the northwest mainly suffered from mild drought and a slightly wet condition during the dry season. Different from that, the RRD mainly had moderately to very wet conditions throughout the year. The areas of both agricultural and forested lands associated with severe drought in the dry season were larger than those in the wet season. Generally, VIC-based soil moisture approach offered a feasible solution for improving soil moisture and agricultural drought monitoring capabilities at the regional scale.

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Spatial and Temporal Features of the Growth of a Bacterial Species Colonizing the Zebrafish Gut

mBio ◽

10.1128/mbio.01751-14 ◽

2014 ◽

Vol 5 (6) ◽

Cited By ~ 62

Author(s):

Matthew Jemielita ◽

Michael J. Taormina ◽

Adam R. Burns ◽

Jennifer S. Hampton ◽

Annah S. Rolig ◽

...

Keyword(s):

Fluorescence Microscopy ◽

Spatial Structure ◽

Growth Kinetics ◽

Spatial Organization ◽

Temporal Dynamics ◽

Bacterial Species ◽

Bacterial Load ◽

Light Sheet ◽

Logistic Growth ◽

Light Sheet Fluorescence Microscopy

ABSTRACTThe vertebrate intestine is home to microbial ecosystems that play key roles in host development and health. Little is known about the spatial and temporal dynamics of these microbial communities, limiting our understanding of fundamental properties, such as their mechanisms of growth, propagation, and persistence. To address this, we inoculated initially germ-free zebrafish larvae with fluorescently labeled strains of anAeromonasspecies, representing an abundant genus in the zebrafish gut. Using light sheet fluorescence microscopy to obtain three-dimensional images spanning the gut, we quantified the entire bacterial load, as founding populations grew from tens to tens of thousands of cells over several hours. The data yield the first ever measurements of the growth kinetics of a microbial species inside a live vertebrate intestine and show dynamics that robustly fit a logistic growth model. Intriguingly, bacteria were nonuniformly distributed throughout the gut, and bacterial aggregates showed considerably higher growth rates than did discrete individuals. The form of aggregate growth indicates intrinsically higher division rates for clustered bacteria, rather than surface-mediated agglomeration onto clusters. Thus, the spatial organization of gut bacteria both relative to the host and to each other impacts overall growth kinetics, suggesting that spatial characterizations will be an important input to predictive models of host-associated microbial community assembly.IMPORTANCEOur intestines are home to vast numbers of microbes that influence many aspects of health and disease. Though we now know a great deal about the constituents of the gut microbiota, we understand very little about their spatial structure and temporal dynamics in humans or in any animal: how microbial populations establish themselves, grow, fluctuate, and persist. To address this, we made use of a model organism, the zebrafish, and a new optical imaging technique, light sheet fluorescence microscopy, to visualize for the first time the colonization of a live, vertebrate gut by specific bacteria with sufficient resolution to quantify the population over a range from a few individuals to tens of thousands of bacterial cells. Our results provide unprecedented measures of bacterial growth kinetics and also show the influence of spatial structure on bacterial populations, which can be revealed only by direct imaging.

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Model-Based Estimation of Amazonian Forests Recovery Time after Drought and Fire Events

Forests ◽

10.3390/f12010008 ◽

2020 ◽

Vol 12 (1) ◽

pp. 8

Author(s):

Bruno L. De Faria ◽

Gina Marano ◽

Camille Piponiot ◽

Carlos A. Silva ◽

Vinícius de L. Dantas ◽

...

Keyword(s):

Recovery Time ◽

Regional Scale ◽

Forest Growth ◽

Forest Recovery ◽

Fire Intensity ◽

Natural Ecosystems ◽

Spatial And Temporal Patterns ◽

Southeastern Part ◽

Forest Growth Model ◽

Carbon Losses

In recent decades, droughts, deforestation and wildfires have become recurring phenomena that have heavily affected both human activities and natural ecosystems in Amazonia. The time needed for an ecosystem to recover from carbon losses is a crucial metric to evaluate disturbance impacts on forests. However, little is known about the impacts of these disturbances, alone and synergistically, on forest recovery time and the resulting spatiotemporal patterns at the regional scale. In this study, we combined the 3-PG forest growth model, remote sensing and field derived equations, to map the Amazonia-wide (3 km of spatial resolution) impact and recovery time of aboveground biomass (AGB) after drought, fire and a combination of logging and fire. Our results indicate that AGB decreases by 4%, 19% and 46% in forests affected by drought, fire and logging + fire, respectively, with an average AGB recovery time of 27 years for drought, 44 years for burned and 63 years for logged + burned areas and with maximum values reaching 184 years in areas of high fire intensity. Our findings provide two major insights in the spatial and temporal patterns of drought and wildfire in the Amazon: (1) the recovery time of the forests takes longer in the southeastern part of the basin, and, (2) as droughts and wildfires become more frequent—since the intervals between the disturbances are getting shorter than the rate of forest regeneration—the long lasting damage they cause potentially results in a permanent and increasing carbon losses from these fragile ecosystems.

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Challenges for Diadromous Fishes in a Dynamic Global Environment

Challenges for Diadromous Fishes in a Dynamic Global Environment ◽

10.47886/9781934874080.ch14 ◽

2009 ◽

Keyword(s):

Atlantic Salmon ◽

Regional Scale ◽

Geographical Location ◽

Stream Temperature ◽

Climate Change Scenarios ◽

Spatial And Temporal Patterns ◽

Specific Factors ◽

Thermal Variability

Abstract.-In this paper, we develop logistic stream temperature models for 17 selected sites in northeastern North America and evaluate the potential changes from warming climate under two scenarios (low and medium-high emissions). Classification of the magnitude of the (1) long-term (1980-2002) and (2) annual thermal regimes allowed examination of the relative spatial and temporal patterns of instream thermal variability across the 17 sites. At the regional scale, the classification identified three broad groups of rivers (cool, intermediate, and warm) reflecting geographical location and moderated by site-specific factors. The interannual classification identified four thermal year types reflecting increasing magnitude and variability in the annual thermal regime. The dominance of thermal year types and the frequency of occurrence indicated significant variability between years for all sites and within thermal regions. Under the two climate change scenarios, stream temperatures in the 17 sites are projected to increase by 2050. However, there are regional differences with intermediate and warm region rivers projected to be more affected, particularly under the medium-high emissions scenario. More significantly, the duration of weeks when temperatures exceed 20°C (taken as a threshold of thermal stress for Atlantic salmon Salmo salar) is projected to increase with variability in response between river groups. We comment on the ecological significance of these potential future increases in stream temperature and duration for Atlantic salmon in the region.

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Net Primary Production in the Shortgrass Steppe

Ecology of the Shortgrass Steppe ◽

10.1093/oso/9780195135824.003.0016 ◽

2008 ◽

Author(s):

William K. Lauenroth ◽

Daniel G. Milchunas

Keyword(s):

Global Change ◽

Primary Production ◽

Net Primary Production ◽

Regional Scale ◽

Ecosystem Dynamics ◽

Shortgrass Steppe ◽

Annual Precipitation ◽

Mean Annual Precipitation ◽

Spatial And Temporal Patterns ◽

Temporal And Spatial

Net primary production (NPP), the amount of carbon or energy fixed by green plants in excess of their respiratory needs, is the fundamental quantity upon which all heterotrophs and the ecosystem processes they are associated with depend. Understanding NPP is therefore a prerequisite to understanding ecosystem dynamics. Our objectives for this chapter are to describe the current state of our knowledge about the temporal and spatial patterns of NPP in the shortgrass steppe, to evaluate the important variables that control NPP, and to discuss the future of NPP in the shortgrass steppe given current hypotheses about global change. Most of the data available for NPP in the shortgrass steppe are for aboveground net primary production (ANPP), so most of our presentation will focus on ANPP and we will deal with belowground net primary production (BNPP) as a separate topic. Furthermore, our treatment of NPP in this chapter will ignore the effects of herbivory, which will be covered in detail in chapter 16. Our approach will be to start with a regional-scale view of ANPP in shortgrass ecosystems and work toward a site-scale view. We will begin by briefly placing ANPP in the shortgrass steppe in its larger context of the central North American grassland region. We will then describe the regional-scale patterns and controls on ANPP, and then move to the site-scale patterns and controls on ANPP. At the site scale, we will describe both temporal and spatial dynamics, and controls on ANPP as well as BNPP. We will then discuss relationships between spatial and temporal patterns in ANPP and end the chapter with a short, speculative section on how future global change may influence NPP in the shortgrass steppe. Temperate grasslands in central North America are found over a range of mean annual precipitation from 200 to 1200 mm.y–1 and mean annual temperatures from 0 to 20 oC (Lauenroth et al., 1999). The widely cited relationship between mean annual precipitation and average annual ANPP allows us to convert the precipitation gradient into a production gradient (Lauenroth, 1979; Lauenroth et al., 1999; Noy-Meir, 1973; Rutherford, 1980; Sala et al., 1988b).

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Predicting microbial redox dynamics and nutrient cycling in the subsurface considering spatio-temporal heterogeneities

10.5194/egusphere-egu2020-3389 ◽

2020 ◽

Author(s):

Swamini Khurana ◽

Falk Heße ◽

Martin Thullner

Keyword(s):

Nutrient Cycling ◽

Temporal Dynamics ◽

Regional Scale ◽

Water Flux ◽

Biogeochemical Cycles ◽

Ecosystem Functions ◽

Microbial Dynamics ◽

Nitrogen Budgets ◽

Carbon And Nitrogen ◽

Nitrogen Cycles

Biogeochemical cycles are extensively studied as they control the flow of matter (carbon and nitrogen, specifically) up to the global scale, further impacting ecosystem functions and services. To be able to predict carbon and nitrogen budgets, it is necessary to study carbon and nitrogen cycles in all compartments of the biosphere, from forests to water, to soil and deep subsurface. Since the soil and deeper subsurface compartments store a high share of the global carbon and nitrogen budget, it is necessary to study the carbon and nitrogen cycles in the subsurface at a higher resolution. Given the spatial heterogeneity and temporal dynamics exhibited by the subsurface, coupled with lack of observational opportunities, the prediction of these cycles in the subsurface is a challenge. For this purpose, this study aims to resolve microbial mediated carbon and nitrogen dynamics in the subsurface with respect to spatial and temporal heterogeneity using a numerical modeling approach. The model considers the response of microbial growth and activity to varying environmental conditions such as access to nutrients and energy sources.The obtained results show a linear relationship between the relative impact on carbon and nitrogen removal and relative difference in breakthrough times between homogeneous scenarios and the spatially heterogeneous scenarios. In contrast, the temporal dynamics of changing flow rates induces minimal aggregated impact on the carbon and nitrogen cycles in the subsurface. This implies that short term temporal dynamics do little to influence the long-term nutrient cycles, given the same average water flux through the entire simulation period. The findings of this study can assist in identification of drivers of microbial dynamics and nutrient cycling in the Critical Zone. This, in turn, can assist towards the regional scale modeling of biogeochemical cycles resulting from microbial dynamics.

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Characterization of extreme meteo-hydrological events in the Alpine Region: historical picture and future scenarios

10.5194/egusphere-egu2020-498 ◽

2020 ◽

Author(s):

Matteo Pesce ◽

Larisa Tarasova ◽

Ralf Merz ◽

Jost von Hardenberg ◽

Alberto Viglione

Keyword(s):

Climate Change ◽

Time Series ◽

Temporal Dynamics ◽

Regional Scale ◽

Alpine Region ◽

Precipitation Extremes ◽

Climate Indices ◽

European Alps ◽

Flood Events ◽

River Flood

In the European Alps, climate change has determined changes in extreme precipitation and river flood events, which impact the population living downstream with increasing frequency. The objectives of our work are:<ol><li>to determine what types of precipitation extremes and river flood events occur in the Alpine Region, based on their generating mechanisms (e.g., frontal convergence storms, convective storms, snow-melt floods, rain-on-snow floods, short and long rain floods, flash floods, ...)</li> <li>to determine the spatial and seasonal distribution of these event types (e.g., their dependence on elevation, geographical location, catchment size, ...) and how precipitation extremes relate to the floods they produce (e.g., the role of snow precipitation and accumulation)</li> <li>to determine whether the event type distribution is changing and will change in the future (e.g., due to climate change).&#160;&#160;</li> </ol>To these aims, we will compile and analyze historical time series of precipitation and discharge in order to identify events in terms of intensity, duration, and spatial extent. We will use the ETCCDI indices as a measure of the precipitation distribution and hydrograph separation techniques for flow events, following the methodology of Tarasova et al. (2018). We will then characterize each event in terms of generation mechanisms. Furthermore, we will analyze the frequency and magnitude of the different event types in different locations and time of the year and determine whether clusters exist by applying automatic techniques (e.g. K-means clustering algorithm). Finally, we will correlate statistics of precipitation and flood event types with climate indices related to large scale atmospheric circulation, such as Atmospheric Blocking, NAO, etc. (Ciccarelli et al. 2008). Results will be then used for the projection of future storm and flood scenarios.We will first apply the methodology in Piedmont by comparing the station-based time series with the NWIOI dataset (ARPA Piemonte) and reanalysis datasets by ECMWF (ERA5, ERA5-Land). We will use a rainfall-runo&#239;&#172;&#128; model at the daily and sub-daily timescale, through calibration at the regional scale, useful for the simulation of soil saturation and snowpack. We expect to find a statistical correlation between the different datasets, but with changing statistical features over space and time within the single datasets. We aim to provide a detailed picture of the different types of events according to the spatial location and season. The results will be useful,&#160;from a scientific perspective, to better understand storm and flood regimes and their change in the Alpine Region, and, from a practical perspective,&#160;to better mitigate the risk associated with the occurrence of extreme events. &#160;&#160;&#160;&#160;&#160;Ciccarelli, N., Von Hardenberg, J., Provenzale, A., Ronchi, C., Vargiu, A., & Pelosini, R. (2008). Climate variability in north-western Italy during the second half of the 20th century. Global and Planetary Change, 63(2-3), 185-195.&#160;https://doi.org/10.1016/j.gloplacha.2008.03.006Tarasova, L., Basso, S., Zink, M., & Merz, R.&#160;(2018). Exploring controls on&#160;rainfall-runoff events: 1. Time&#160;series-based event separation and&#160;temporal dynamics of event runoff&#160;response in Germany. Water Resources&#160;Research, 54, 7711&#8211;7732. https://doi.org/10.1029/2018WR022587

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Biogeographic Patterns in Genomic Diversity among a Large Collection of Vibrio cholerae Isolates

Applied and Environmental Microbiology ◽

10.1128/aem.01304-08 ◽

2009 ◽

Vol 75 (6) ◽

pp. 1658-1666 ◽

Cited By ~ 26

Author(s):

Daniel P. Keymer ◽

Lilian H. Lam ◽

Alexandria B. Boehm

Keyword(s):

Vibrio Cholerae ◽

Temporal Dynamics ◽

Consensus Sequence ◽

Regional Scale ◽

Geographic Distance ◽

Genomic Diversity ◽

Central California ◽

Biogeographic Patterns ◽

Community Model ◽

Environmental Similarity

ABSTRACT Vibrio cholerae strains are capable of inhabiting multiple niches in the aquatic environment and in some cases cause disease in humans. However, the ecology and biodiversity of these bacteria in environmental settings remains poorly understood. We used the genomic fingerprinting technique enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) to profile 835 environmental isolates from waters and sediments obtained at nine sites along the central California coast. We identified 115 ERIC-PCR genotypes from 998 fingerprints, with a reproducibility of 98.5% and a discriminatory power of 0.971. When the temporal dynamics at a subset of sampling sites were explored, several genotypes provided evidence for cosmopolitan or geographically restricted distributions, and other genotypes displayed nonrandom patterns of cooccurrence. Partial Mantel tests confirmed that genotypic similarity of isolates across all sampling events was correlated with environmental similarity (0.04 ≤ r ≤ 0.05), temporal proximity (r = 0.09), and geographic distance (r = 0.09). A neutral community model for all sampling events explained 61% of the variation in genotype abundance. Cooccurrence indices (C-score, C-board, and Combo) were significantly different than expected by chance, suggesting that the V. cholerae population may have a competitive structure, especially at the regional scale. Even though stochastic processes are undoubtedly important in generating biogeographic patterns in diversity, deterministic factors appear to play a significant, albeit small, role in shaping the V. cholerae population structure in this system.

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A tree-ring reconstruction of western spruce budworm outbreaks in the San Juan Mountains, Colorado, U.S.A.

Canadian Journal of Forest Research ◽

10.1139/x03-026 ◽

2003 ◽

Vol 33 (6) ◽

pp. 1010-1028 ◽

Cited By ~ 53

Author(s):

Daniel E Ryerson ◽

Thomas W Swetnam ◽

Ann M Lynch

Keyword(s):

Tree Ring ◽

Regional Scale ◽

Spruce Budworm ◽

Western Spruce Budworm ◽

Spatial And Temporal Patterns ◽

Control Series ◽

Increment Core ◽

San Juan Mountains ◽

Mixed Conifer Forests ◽

Tree Ring Reconstruction

Tree-ring records were used to reconstruct spatial and temporal patterns of western spruce budworm (Choristoneura occidentalis Freeman) outbreaks in mixed conifer forests of southern Colorado. Reconstructions in 11 host stands showed a regionally synchronous pattern of at least 14 outbreaks during the past 350 years. Intervals between outbreaks were highly variable within stands, but at the regional scale outbreak intervals were more consistent. Spectral analyses of regional outbreak time series confirmed periodicities at about 25, 37, and 83 years. Comparison with an independent drought reconstruction indicated that outbreaks typically corresponded to increased moisture, while relatively little budworm activity occurred during dry periods. In contrast to other published reconstructions in Colorado and New Mexico, reconstructions from this study area did not exhibit significant 20th-century changes in the frequency of outbreak occurrence or magnitude of growth reduction. Sharply reduced growth during outbreaks was not clearly visible on the increment core samples, and budworm-induced reductions in tree-ring growth were usually detectable only after comparison with nonhost tree-ring series. This finding emphasizes that defoliation effects on ring growth can be highly relativistic. Hence, caution should be exercised in reconstructing insect outbreak histories based only on visual detection approaches, or without comparison with nonhost or nondefoliated tree-ring control series.

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