Community patch‐dynamics governs direct and indirect nutrient recycling by aggregated animals across spatial scales

2021 ◽  
Author(s):  
Carla L. Atkinson ◽  
Kenneth Forshay
Keyword(s):  
Spatial Scales ◽  
Nutrient Recycling ◽  
Patch Dynamics

scholarly journals Patch dynamics and the development of structural and spatial heterogeneity in Pacific Northwest forests

2011 ◽  
Vol 41 (12) ◽  
pp. 2276-2291 ◽  
Author(s):  
Van R. Kane ◽  
Rolf F. Gersonde ◽  
James A. Lutz ◽  
Robert J. McGaughey ◽  
Jonathan D. Bakker ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Stand Structure ◽  
Spatial Scales ◽  
Canopy Structure ◽  
Patch Dynamics ◽  
Spatial Arrangement ◽  
Airborne Lidar ◽  
Small Scale ◽  
Individual Site ◽  
Time Required

Over time, chronic small-scale disturbances within forests should create distinct stand structures and spatial patterns. We tested this hypothesis by measuring the structure and spatial arrangement of gaps and canopy patches. We used airborne LiDAR data from 100 sites (cumulative 11.2 km2) in the Pacific Northwest, USA, across a 643 year chronosequence to measure canopy structure, patch and gap diversity, and scales of variance. We used airborne LiDAR’s ability to identify strata in canopy surface height to distinguish patch spatial structures as homogeneous canopy structure, matrix–patch structures, or patch mosaics. We identified six distinct stand structure classes that were associated with the canopy closure, competitive exclusion, maturation, and three patch mosaics stages of late seral forest development. Structural variance peaked in all classes at the tree-to-tree and tree-to-gap scales (10–15 m), but many sites maintained high variance at scales >30 m and up to 200 m, emphasizing the high patch-to-patch heterogeneity. The time required to develop complex patch and gap structures was highly variable and was likely linked to individual site circumstances. The high variance at larger scales appears to be an emergent property that is not a simple propagation of processes observed at smaller spatial scales.

scholarly journals Local disease–ecosystem–livelihood dynamics: reflections from comparative case studies in Africa

2017 ◽  
Vol 372 (1725) ◽  
pp. 20160163 ◽  
Author(s):  
Melissa Leach ◽  
Bernard Bett ◽  
M. Said ◽  
Salome Bukachi ◽  
Rosemary Sang ◽  
...  
Keyword(s):  
Case Studies ◽  
One Health ◽  
Cultural Practices ◽  
Spatial Scales ◽  
Patch Dynamics ◽  
Well Being ◽  
Valley Fever ◽  
Humid Forest ◽  
Trade Offs ◽  
Ecosystem Interactions

This article explores the implications for human health of local interactions between disease, ecosystems and livelihoods. Five interdisciplinary case studies addressed zoonotic diseases in African settings: Rift Valley fever (RVF) in Kenya, human African trypanosomiasis in Zambia and Zimbabwe, Lassa fever in Sierra Leone and henipaviruses in Ghana. Each explored how ecological changes and human–ecosystem interactions affect pathogen dynamics and hence the likelihood of zoonotic spillover and transmission, and how socially differentiated peoples’ interactions with ecosystems and animals affect their exposure to disease. Cross-case analysis highlights how these dynamics vary by ecosystem type, across a range from humid forest to semi-arid savannah; the significance of interacting temporal and spatial scales; and the importance of mosaic and patch dynamics. Ecosystem interactions and services central to different people's livelihoods and well-being include pastoralism and agro-pastoralism, commercial and subsistence crop farming, hunting, collecting food, fuelwood and medicines, and cultural practices. There are synergies, but also tensions and trade-offs, between ecosystem changes that benefit livelihoods and affect disease. Understanding these can inform ‘One Health’ approaches towards managing ecosystems in ways that reduce disease risks and burdens. This article is part of the themed issue ‘One Health for a changing world: zoonoses, ecosystems and human well-being’.

Resistance, resilience, and patchiness of invertebrate assemblages in native tussock and pasture streams in New Zealand after a hydrological disturbance

2003 ◽  
Vol 60 (6) ◽  
pp. 731-739 ◽  
Author(s):  
Adriano S Melo ◽  
Dev K Niyogi ◽  
Christoph D Matthaei ◽  
Colin R Townsend
Keyword(s):  
Species Richness ◽  
New Zealand ◽  
Spatial Scales ◽  
Patch Dynamics ◽  
Natural Disturbance ◽  
Species Density ◽  
Land Uses ◽  
Invertebrate Abundance ◽  
Invertebrate Assemblages

We generated hydrological disturbances to investigate the role of disturbance in New Zealand streams in two land uses: native tussock grasslands and exotic pasture catchments. We tested whether physical differences in streambed structure confer higher resistance and resilience in tussock sites than in pasture sites. We also investigated changes in patchiness (at spatial scales larger than 0.06 m2) caused by the disturbance. Invertebrate abundance decreased immediately after the disturbance. Species density remained unchanged, but species richness (rarefied) increased. Eight days after the disturbance event, abundance and species richness (rarefied) were similar to those of samples collected immediately before the disturbance. Resistance (measured as decrease in abundance) and resilience (measured as recovery within 8 days) did not differ significantly between the land uses. Patchiness increased in both stream types immediately after the disturbance but decreased to predisturbance levels after 8 days. Disturbance caused a redistribution of individuals among patches, some receiving individuals, others losing individuals, and some remaining unchanged. Our results conform with predictions of the patch dynamics concept and are consistent with results of studies of natural disturbance caused by floods.

scholarly journals The emergence of the rescue effect from explicit within- and between-patch dynamics in a metapopulation

2014 ◽  
Author(s):  
Anders Eriksson ◽  
Federico Elías-Wolff ◽  
Bernhard Mehlig ◽  
Andrea Manica
Keyword(s):  
Stochastic Dynamics ◽  
Spatial Scales ◽  
Local Population ◽  
Patch Dynamics ◽  
Analytical Framework ◽  
Environmental Stochasticity ◽  
Demographic Stochasticity ◽  
Rescue Effect ◽  
Wide Range ◽  
The Stability

Immigration can rescue local populations from extinction, helping to stabilise a metapopulation. Local population dynamics is important for determining the strength of this rescue effect, but the mechanistic link between local demographic parameters and the rescue effect at the metapopulation level has received very little attention by modellers. We develop an analytical framework that allows us to describe the emergence of the rescue effect from interacting local stochastic dynamics. We show this framework to be applicable to a wide range of spatial scales, providing a powerful and convenient alternative to individual-based models for making predictions concerning the fate of metapopulations. We show that the rescue effect plays an important role in minimising the increase in local extinction probability associated with high demographic stochasticity, but its role is more limited in the case of high local environmental stochasticity of recruitment or survival. While most models postulate the rescue effect, our framework provides an explicit mechanistic link between local dynamics and the emergence of the rescue effect, and more generally the stability of the whole metapopulation. Now published as: Proceedings of the Royal Society B, 2014, 281(1780):20133127 doi:10.1098/rspb.2013.3127

Coral mucus release and following particle trapping contribute to rapid nutrient recycling in a Northern Red Sea fringing reef

2010 ◽  
Vol 61 (9) ◽  
pp. 1006 ◽  
Author(s):  
Florian W. Mayer ◽  
Christian Wild
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Red Sea ◽  
Spatial Scales ◽  
Nutrient Recycling ◽  
Coupling Mechanism ◽  
Particle Trapping ◽  
Coral Mucus ◽  
Coral Genus ◽  
Northern Red Sea

Mucus released by corals can function as an important energy carrier and particle trap in reef ecosystems with strong tidal currents. In fringing reefs with calm conditions, these processes may occur on smaller spatial scales. Observations of coral mucus dynamics in the Northern Red Sea revealed highly particle-enriched and negatively buoyant mucus strings attached to ∼27% of coral colonies for up to 79 min. Mucus strings of the scleractinian coral genus Acropora exhibited three orders of magnitude higher particulate organic carbon and nitrogen concentrations when compared with freshly released coral mucus, which confirms efficient particle trapping. After detachment from the coral surface, more than 95% of mucus strings rapidly descended to the reef sea floor within less than 1 m. Such mucus-induced transport may account for 21–25% of the total sedimentary particulate organic matter supply. In situ and laboratory analyses of planktonic and benthic microbial degradation of mucus strings showed high rates of up to 16 and 26% particulate organic carbon h–1, respectively. These findings suggest a newly discovered, tight sediment–water coupling mechanism via coral mucus that may contribute to rapid nutrient recycling in oligotrophic fringing coral reefs.

Patch Dynamics

Ecology ◽  
2013 ◽  
Author(s):  
Lindsey Gillson
Keyword(s):  
Spatial Scales ◽  
Heterogeneous Systems ◽  
Patch Dynamics ◽  
Disturbance Ecology ◽  
Hierarchy Theory ◽  
Spatial And Temporal Scales ◽  
Space And Time ◽  
Nonequilibrium Dynamic ◽  
Metapopulation Theory ◽  
Individual Trees

Patch dynamics is the study of spatial patterns in landscapes and the ecological and environmental processes that generate these patterns, plus the internal dynamics of how patches change over time. “Patches” are spatial units differing from their neighbors. They are not necessarily internally homogeneous, but may be further decomposable to smaller spatial scales. For example, a forest ecosystem is composed of stands of trees, but each stand is composed of individual trees. By studying the dynamics of patches over space and time, ecologists have sought to address one of the fundamental matters in ecology—understanding the linkages between pattern, process, and scale. This theme underpins landscape ecology, disturbance ecology, and the spatial aspects of population ecology, which is the basis for metapopulation theory and metacommunity theory. All of these branches of ecology are concerned with flux/nonequilibrium: dynamic, heterogeneous systems, may appear stable at some spatial and temporal scales and stable at others. The persistence of patch dynamic landscapes despite their dynamism led to the concept of the shifting mosaic steady state. Pursuing the question of how to bridge the gaps between processes at different spatial scales led to the amalgam of patch dynamics and hierarchy theory. Covering the dimensions of both space and time, patch dynamics has been of fundamental importance in biodiversity conservation, and it provides a spatial and temporal basis for natural resource management and managing and conserving complex systems. Patch dynamics intersects with numerous other important concepts in ecology, including the island theory of biogeography, Metapopulation Theory, succession, and disturbance ecology.

scholarly journals The emergence of the rescue effect from explicit within- and between-patch dynamics in a metapopulation

2014 ◽  
Vol 281 (1780) ◽  
pp. 20133127 ◽  
Author(s):  
Anders Eriksson ◽  
Federico Elías-Wolff ◽  
Bernhard Mehlig ◽  
Andrea Manica
Keyword(s):  
Stochastic Dynamics ◽  
Spatial Scales ◽  
Local Population ◽  
Patch Dynamics ◽  
Analytical Framework ◽  
Environmental Stochasticity ◽  
Demographic Stochasticity ◽  
Rescue Effect ◽  
Wide Range ◽  
The Stability

Immigration can rescue local populations from extinction, helping to stabilize a metapopulation. Local population dynamics is important for determining the strength of this rescue effect, but the mechanistic link between local demographic parameters and the rescue effect at the metapopulation level has received very little attention by modellers. We develop an analytical framework that allows us to describe the emergence of the rescue effect from interacting local stochastic dynamics. We show this framework to be applicable to a wide range of spatial scales, providing a powerful and convenient alternative to individual-based models for making predictions concerning the fate of metapopulations. We show that the rescue effect plays an important role in minimizing the increase in local extinction probability associated with high demographic stochasticity, but its role is more limited in the case of high local environmental stochasticity of recruitment or survival. While most models postulate the rescue effect, our framework provides an explicit mechanistic link between local dynamics and the emergence of the rescue effect, and more generally the stability of the whole metapopulation.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

Spatial regularities between non-immigrant and immigrant numbers in Canada

2014 ◽  
Vol 11 (1) ◽  
pp. 90-100
Author(s):  
Yigit Aydede
Keyword(s):  
Fixed Effects ◽  
Spatial Scales ◽  
National Scale ◽  
Pooled Data

The present study intends to reveal spatial regularities between non-immigrant and immigrant numbers in two different ways. First, it questions the existence of those regularities when spatial scales get finer. Second, it uses pooled data over four population censuses covering the period from 1991 to 2006, which enabled us to apply appropriate techniques to remove those unobserved fixed effects so that the estimations would accurately identify the linkage between local immigrant and non-immigrant numbers. The results provide evidence about the existence of negative spatial regularities between non-immigrant and immigrant numbers in Canada at national scale.

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