scholarly journals Regulation of trophic architecture across spatial scales in a major river network

2018 ◽  
Author(s):  
Eric Harvey ◽  
Florian Altermatt
Keyword(s):  
Trophic Structure ◽  
Spatial Scales ◽  
Monitoring Program ◽  
Trophic Group ◽  
Ecosystem Functions ◽  
Rhine River ◽  
Cascading Effects ◽  
Environmental Perturbations ◽  
Stream Macroinvertebrate ◽  
Path Analysis Approach

AbstractMoving beyond species count data is an essential step to better understand the effects of environmental perturbations on biodiversity and ecosystem functions, and to eventually better predict the strength and direction of those effects. Here, coupling an integrative path analysis approach with data from an extensive countrywide monitoring program, we tested the main spatial, environmental and anthropogenic drivers of change in stream macroinvertebrate trophic structure along the entire Swiss Rhine river catchment. Trophic structure was largely driven by inherent altitudinal variation influencing and cascading to regional scaled factors such as land use change and position in the riverine network, which, in turn, transformed local habitat structure variables. Those cascading effects across scales propagated through the biotic community, first affecting preys and, in turn, predators. Our results illustrate how seemingly less important factors can act as essential transmission belts, propagating through direct and indirect pathways across scales to generate the specific context in which each trophic group will strive or not, leading to characteristic landscape wide variations in trophic community structure.

scholarly journals Biogeography of acoustic biodiversity of NW Mediterranean coralligenous reefs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lucia Di Iorio ◽  
Manon Audax ◽  
Julie Deter ◽  
Florian Holon ◽  
Julie Lossent ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Western Mediterranean ◽  
Ecosystem Functions ◽  
Marine Biodiversity ◽  
Predator Species ◽  
The North ◽  
Mediterranean Habitats ◽  
Geographical Regions ◽  
Nw Mediterranean

AbstractMonitoring the biodiversity of key habitats and understanding the drivers across spatial scales is essential for preserving ecosystem functions and associated services. Coralligenous reefs are threatened marine biodiversity hotspots that are challenging to monitor. As fish sounds reflect biodiversity in other habitats, we unveiled the biogeography of coralligenous reef sounds across the north-western Mediterranean using data from 27 sites covering 2000 km and 3 regions over a 3-year period. We assessed how acoustic biodiversity is related to habitat parameters and environmental status. We identified 28 putative fish sound types, which is up to four times as many as recorded in other Mediterranean habitats. 40% of these sounds are not found in other coastal habitats, thus strongly related to coralligenous reefs. Acoustic diversity differed between geographical regions. Ubiquitous sound types were identified, including sounds from top-predator species and others that were more specifically related to the presence of ecosystem engineers (red coral, gorgonians), which are key players in maintaining habitat function. The main determinants of acoustic community composition were depth and percentage coverage of coralligenous outcrops, suggesting that fish-related acoustic communities exhibit bathymetric stratification and are related to benthic reef assemblages. Multivariate analysis also revealed that acoustic communities can reflect different environmental states. This study presents the first large-scale map of acoustic fish biodiversity providing insights into the ichthyofauna that is otherwise difficult to assess because of reduced diving times. It also highlights the potential of passive acoustics in providing new aspects of the correlates of biogeographical patterns of this emblematic habitat relevant for monitoring and conservation.

scholarly journals Spatial Variation in Canopy Structure across Forest Landscapes

2018 ◽  
Author(s):  
Brady S. Hardiman ◽  
Elizabeth A. LaRue ◽  
Jeff W. Atkins ◽  
Robert T. Fahey ◽  
Franklin W. Wagner ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Forest Canopy ◽  
Spatial Scales ◽  
Canopy Structure ◽  
Ecosystem Functions ◽  
Lidar System ◽  
Stable Point ◽  
Eastern Usa ◽  
Forested Landscapes ◽  
Patch Scale

Forest canopy structure (CS) controls many ecosystem functions and is highly variable across landscapes, but the magnitude and scale of this variation is not well understood. We used a portable canopy lidar system to characterize variation in five categories of CS along N = 3 transects (140–800 m long) at each of six forested landscapes within the eastern USA. The cumulative coefficient of variation was calculated for subsegments of each transect to determine the point of stability for individual CS metrics. We then quantified the scale at which CS is autocorrelated using Moran’s I in an Incremental Autocorrelation analysis. All CS metrics reached stable values within 300 m but varied substantially within and among forested landscapes. A stable point of 300 m for CS metrics corresponds with the spatial extent that many ecosystem functions are measured and modeled. Additionally, CS metrics were spatially autocorrelated at 40 to 88 m, suggesting that patch scale disturbance or environmental factors drive these patterns. Our study shows CS is heterogeneous across temperate forest landscapes at the scale of 10’s of meters, requiring a resolution of this size for upscaling CS with remote sensing to large spatial scales.

Satellite-based monitoring of biodiversity

2019 ◽  
pp. 20-36
Author(s):  
Nathalie Pettorelli
Keyword(s):  
Remote Sensing ◽  
Genetic Structure ◽  
Satellite Remote Sensing ◽  
Spatial Scales ◽  
Species Traits ◽  
Ecosystem Functions ◽  
Multiple Spatial Scales ◽  
Satellite Information ◽  
Monitoring Of Biodiversity ◽  
Composition Structure

This chapter explores how satellite information can help track biodiversity at multiple spatial scales and resolutions. To attempt to capture the various organisational dimensions of biodiversity, the chapter focuses on six classes of variables: genetic structure and composition, species populations, species traits, ecosystem extent and structure, ecosystem composition, and ecosystem functions. From helping map species and ecosystem distribution to supporting the monitoring of ecosystem composition, structure, and functioning, this contribution provides a series of examples that demonstrate how satellite remote sensing can open multiple opportunities for various stakeholders to improve on the management of wildlife. The chapter concludes with a discussion on limitations and possible ways forward.

scholarly journals The Origin, Succession, and Predicted Metabolism of Bacterial Communities Associated with Leaf Decomposition

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Sara L. Jackrel ◽  
Jack A. Gilbert ◽  
J. Timothy Wootton
Keyword(s):  
Bacterial Community ◽  
Nutrient Cycling ◽  
Intraspecific Variation ◽  
Bacterial Communities ◽  
Spatial Scales ◽  
Gene Content ◽  
Ecosystem Functions ◽  
Species Variation ◽  
Decomposition Rates ◽  
Home Field Advantage

ABSTRACT Intraspecific variation in plant nutrient and defensive traits can regulate ecosystem-level processes, such as decomposition and transformation of plant carbon and nutrients. Understanding the regulatory mechanisms of ecosystem functions at local scales may facilitate predictions of the resistance and resilience of these functions to change. We evaluated how riverine bacterial community assembly and predicted gene content corresponded to decomposition rates of green leaf inputs from red alder trees into rivers of Washington State, USA. Previously, we documented accelerated decomposition rates for leaves originating from trees growing adjacent to the site of decomposition versus more distant locales, suggesting that microbes have a “home-field advantage” in decomposing local leaves. Here, we identified repeatable stages of bacterial succession, each defined by dominant taxa with predicted gene content associated with metabolic pathways relevant to the leaf characteristics and course of decomposition. “Home” leaves contained bacterial communities with distinct functional capacities to degrade aromatic compounds. Given known spatial variation of alder aromatics, this finding helps explain locally accelerated decomposition. Bacterial decomposer communities adjust to intraspecific variation in leaves at spatial scales of less than a kilometer, providing a mechanism for rapid response to changes in resources such as range shifts among plant genotypes. Such rapid responses among bacterial communities in turn may maintain high rates of carbon and nutrient cycling through aquatic ecosystems. IMPORTANCE Community ecologists have traditionally treated individuals within a species as uniform, with individual-level biodiversity rarely considered as a regulator of community and ecosystem function. In our study system, we have documented clear evidence of within-species variation causing local ecosystem adaptation to fluxes across ecosystem boundaries. In this striking pattern of a “home-field advantage,” leaves from individual trees tend to decompose most rapidly when immediately adjacent to their parent tree. Here, we merge community ecology experiments with microbiome approaches to describe how bacterial communities adjust to within-species variation in leaves over spatial scales of less than a kilometer. The results show that bacterial community compositional changes facilitate rapid ecosystem responses to environmental change, effectively maintaining high rates of carbon and nutrient cycling through ecosystems.

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.

SOFT-CLIFF RETREAT, SELF-ORGANIZED CRITICAL PHENOMENA IN THE LIMIT OF PREDICTABILITY?

Fractals ◽  
2015 ◽  
Vol 23 (01) ◽  
pp. 1540009 ◽  
Author(s):  
CARLOS PAREDES ◽  
CLARA GODOY ◽  
RICARDO CASTEDO
Keyword(s):  
Spatial Scales ◽  
Monitoring Program ◽  
Limited Range ◽  
Dynamic Features ◽  
Cliff Erosion ◽  
Complex Interactions ◽  
Self Organized ◽  
Wide Range ◽  
Coastal Cliffs ◽  
Gravity Driven

The coastal erosion along the world's coastlines is a natural process that occurs through the actions of marine and subaerial physico-chemical phenomena, waves, tides, and currents. The development of cliff erosion predictive models is limited due to the complex interactions between environmental processes and material properties over a wide range of temporal and spatial scales. As a result of this erosive action, gravity driven mass movements occur and the coastline moves inland. Like other studied earth natural and synthetically modelled phenomena characterized as self-organized critical (SOC), the recession of the cliff has a seemingly random, sporadic behavior, with a wide range of yearly recession rate values probabilistically distributed by a power-law. Usually, SOC systems are defined by a number of scaling features in the size distribution of its parameters and on its spatial and/or temporal pattern. Particularly, some previous studies of derived parameters from slope movements catalogues, have allowed detecting certain SOC features in this phenomenon, which also shares the recession of cliffs. Due to the complexity of the phenomenon and, as for other natural processes, there is no definitive model of recession of coastal cliffs. In this work, various analysis techniques have been applied to identify SOC features in the distribution and pattern to a particular case: the Holderness shoreline. This coast is a great case study to use when examining coastal processes and the structures associated with them. It is one of World's fastest eroding coastlines (2 m/yr in average, max observed 22 m/yr). Cliffs, ranging from 2 m up to 35 m in height, and made up of glacial tills, mainly compose this coast. It is this soft boulder clay that is being rapidly eroded and where coastline recession measurements have been recorded by the Cliff Erosion Monitoring Program (East Riding of Yorkshire Council, UK). The original database has been filtered by grouping contiguous sections, with similar geomorphological and dynamic features, to configure a complete and suitable catalogue of yearly recession rates (in m/yr) to analyze. Results show SOC fingerprint characteristics in the limited range scaling of the probability distribution function, in the variographic analysis and in the zero-mean Gaussian distribution of the Fourier coefficients. Therefore it cannot be neglected the possibility that Holderness cliffs behave as a SOC system. According to the discussed results, predictability possibilities of sea-cliff recession phenomena have been concluded.

Environmental heterogeneity and β diversity of stream macroinvertebrate communities at intermediate spatial scales

2013 ◽  
Vol 32 (1) ◽  
pp. 142-154 ◽  
Author(s):  
Jani Heino ◽  
Mira Grönroos ◽  
Jari Ilmonen ◽  
Tommi Karhu ◽  
Maija Niva ◽  
...  
Keyword(s):  
Environmental Heterogeneity ◽  
Spatial Scales ◽  
Macroinvertebrate Communities ◽  
Β Diversity ◽  
Stream Macroinvertebrate

scholarly journals Benthic macroinvertebrates and degradation of phytomass as indicators of ecosystem functions in flooded rice cropping

2017 ◽  
Vol 52 (4) ◽  
pp. 261-270 ◽  
Author(s):  
Lilian Terezinha Winckler ◽  
Angélica Konradt Güths ◽  
Pâmela Rodrigues Gayer
Keyword(s):  
Benthic Macroinvertebrates ◽  
Trophic Group ◽  
Ecosystem Functions ◽  
Conventional System ◽  
Natural Wetland ◽  
Wetland Area ◽  
Organic System ◽  
Flooded Rice ◽  
Rice Area ◽  
Conventional Systems

Abstract: The objective of this work was to evaluate the ecosystem functions of a natural wetland and of artificially flooded rice areas, managed under organic and conventional systems, by phytomass degradation and by the colonization of this material by benthic macroinvertebrates. The experiment was carried out in a natural wetland area, and in two flooded rice areas managed under organic and conventional systems. Twenty-five decomposition bags filled with 10 g of dry vegetation were installed in each site. At 14, 28, 42, 56, and 70 days after the beginning of the experiment, five bags from each site were collected. Macroinvertebrates were identified and classified by functional trophic group. The number of species of benthic macroinvertebrates increased: natural wetland > organic system > conventional system. The Chironomidae group was present in all areas, confirming its food plasticity and adaptability to different substrates and environmental stress situations. The Amphipoda group was present only in the artificially flooded rice area, and the Acari, only in the natural wetland. The diversity of species in the natural wetland area was higher than in the artificially flooded rice area. Nutrient cycling, provided by phytomass decomposition, is affected by the management system, and the delay in this process causes a reduction of the ecosystem functions in the conventional system.

scholarly journals Trophic guilds of fishes in sandbank habitats of a Neotropical river

2007 ◽  
Vol 5 (3) ◽  
pp. 399-404 ◽  
Author(s):  
Poliana Ribeiro Pereira ◽  
Carlos Sérgio Agostinho ◽  
Rafael José de Oliveira ◽  
Elineide Eugênio Marques
Keyword(s):  
Trophic Structure ◽  
Drainage Basin ◽  
Trophic Group ◽  
Food Resources ◽  
Food Sources ◽  
Trophic Guilds ◽  
River Drainage ◽  
Central Brazil ◽  
Terrestrial Insects ◽  
River Drainage Basin

The objective of this study was to characterize the trophic structure of the community of fishes exploiting riverine sandbank habitats. Collections were carried out during the period of October 1999 to December 2003, on six sand banks in the upper and middle portions of the Tocantins River drainage basin in central Brazil. The availability of food resources was evaluated based on the volume of the items present in the stomachs of all species. A total of 2,127 stomachs of fish belonging to 50 species were analyzed. Nine main trophic guilds grouped the local ichthyofauna according to diet. Aquatic-origin items were the preferred source for 55.5% of the groups analyzed, whereas terrestrial-origin items composed 44.4%. Items of undetermined origin (detritus and sediment), although present in 89% of the guilds, were the predominant food in only one trophic group. Terrestrial insects and fish were the food sources with the largest biomass available in the environment. Sandbank environments are homogeneous, with little shelter and food available; as a rule, the species that occupy these environments are generalists.

scholarly journals Toward seamless hydrologic predictions across scales

2017 ◽  
Author(s):  
Luis Samaniego ◽  
Rohini Kumar ◽  
Stephan Thober ◽  
Oldrich Rakovec ◽  
Matthias Zink ◽  
...  
Keyword(s):  
Land Surface ◽  
Spatial Scales ◽  
Matching Condition ◽  
Short Review ◽  
Global Scale ◽  
Specific Model ◽  
Rhine River ◽  
Hydrologic Models ◽  
Catchment Scale ◽  
Operational Models

Abstract. Land surface and hydrologic models (LSM/HM) are used at diverse spatial resolutions ranging from 1–10 km in catchment-scale applications to over 50 km in global-scale applications. Application of the same model structure at different spatial scales requires that the model estimates similar fluxes independent of the model resolution and fulfills a flux-matching condition across scales. An analysis of state-of-the-art LSMs and HMs reveals that most do not have consistent and realistic parameter fields for land surface geophysical properties. Multiple experiments with the mHM, Noah-MP, PCR-GLOBWB and WaterGAP models are conducted to demonstrate the pitfalls of poor parameterization practices currently used in most operational models, which are insufficient to satisfy the flux-matching condition. These examples demonstrate that J. Dooge's 1982 statement on the unsolved problem of parameterization in these models remains true. We provide a short review of existing parameter regionalization techniques and discuss a method for obtaining seamless hydrological predictions of water fluxes and states across multiple spatial resolutions. The multiscale parameter regionalization (MPR) technique is a practical and robust method that provides consistent (seamless) parameter and flux fields across scales. A general model protocol is presented to describe how MPR can be applied to a specific model, with an example of this application using the PCR-GLOBWB model. Applying MPR to PCR-GLOBWB substantially improves the flux-matching condition. Estimation of evapotranspiration without MPR at 5 arcmin and 30 arcmin spatial resolutions for the Rhine river basin results in a difference of approximately 29 %. Applying MPR reduce this difference to 9 %. For total soil water, the differences without and with MPR are 25 % and 7 %, respectively.

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