scholarly journals Ecosystem-Scale Effects of Nutrients and Fishing on Coral Reefs

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Sheila M. Walsh
Keyword(s):  
Natural Experiment ◽  
Scale Effects ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Fishing Effort ◽  
Small Scale ◽  
Nutrient Pollution ◽  
Manipulative Experiments ◽  
Reef Decline ◽  
Different Levels

Nutrient pollution and fishing are the primary local causes of coral reef decline but their ecosystem-scale effects are poorly understood. Results from small-scale manipulative experiments of herbivores and nutrients suggest prioritizing management of fishing over nutrient pollution because herbivores can control macroalgae and turf in the presence of nutrients. However, ecological theory suggests that the opposite occurs at large scales. Moreover, it is unclear whether fishing decreases herbivores because fishing of predators may result in an increase in herbivores. To investigate this paradox, data on the fish and benthic communities, fishing, and nutrients were collected on Kiritimati, Kiribati. Oceanographic conditions and a population resettlement program created a natural experiment to compare sites with different levels of fishing and nutrients. Contrary to theory, herbivores controlled macroalgae in the presence of nutrients at large spatial scales, and herbivores had greater effects on macroalgae when nutrients were higher. In addition, fishing did not increase herbivores. These results suggest that protecting herbivores may have greater relative benefits than reducing nutrient pollution, especially on polluted reefs. Reallocating fishing effort from herbivores to invertivores or planktivores may be one way to protect herbivores and indirectly maintain coral dominance on reefs impacted by fishing and nutrient pollution.

scholarly journals Spatial distribution of otter trawl effort in Icelandic waters: comparison of measures of effort and implications for benthic community effects of trawling activities

2003 ◽  
Vol 60 (6) ◽  
pp. 1200-1215 ◽  
Author(s):  
Stefán Áki Ragnarsson ◽  
Sigmar Arnar Steingrímsson
Keyword(s):  
Spatial Distribution ◽  
Scale Effects ◽  
Benthic Communities ◽  
Demersal Fish ◽  
Fishing Effort ◽  
Otter Trawl ◽  
Community Effects ◽  
The North ◽  
Swept Area ◽  
Icelandic Waters

Abstract We examined the spatial distribution of trawling effort from logbook data from all Icelandic vessels fishing for demersal fish between 1991 and 1997 with a spatial resolution of 1 degree of latitude and 1 degree of longitude. The trawling effort was widely distributed but was intensive only in small and localised areas. Three measures of effort were compared; tow frequency, tow duration and separate estimates of swept area for otter boards and trawls. In each year, the area swept with otter trawl was 1.7 times greater than the total area in which fishing occurred over the 7 year period. In contrast, the area swept with otter boards was 4% of the total fishing area. Most of the fishing effort was confined to depths shallower than 400 m. With increasing depth, the size of trawls became larger and accordingly, also the area swept per haul. Calculations assuming no variation in the size of the trawl in relation to depth, produced inaccurate swept area estimates. Furthermore, swept area estimates based on depth corrected door spreads were greater than estimates where no such correction was made. Swept area was considered to be a more appropriate measure of effort than tow frequency and tow duration as long as variation in the size of the gear (e.g. in relation to depth) was taken into account. Effort within Icelandic waters was compared in five depth strata within seven zones. Effort was highest off the south and NW coasts and lowest off the north and east coasts. Effort was most intensive at the 100–500 m depth in all zones but in some areas (such as off NW Iceland), effort extended to deeper waters. Knowledge of the distribution of fishing effort is important for predicting larger scale effects of fishing gears on benthic communities.

Small spatial scale effects of wave action exposure on morphological traits of the limpet Lottia subrugosa

2019 ◽  
Vol 99 (06) ◽  
pp. 1309-1315
Author(s):  
Edson A. Vieira ◽  
Marília Bueno
Keyword(s):  
Spatial Scale ◽  
Scale Effects ◽  
Spatial Scales ◽  
Wave Exposure ◽  
Wave Action ◽  
Shell Shape ◽  
Small Scale ◽  
Small Spatial Scale ◽  
Large Spatial Scale ◽  
Exposed Shore

AbstractMany studies have already assessed how wave action may affect morphology of intertidal species among sites that vary in wave exposure, but few attempted to look to this issue in smaller scales. Using the most common limpet of the Brazilian coast, Lottia subrugosa, and assuming position on rocky boulders as a proxy for wave action at small scale, we tested the hypothesis that waves may also influence limpet morphology at a smaller spatial scale by investigating how individual size, foot area and shell shape vary between sheltered and exposed boulder sides on three shores in the coast of Ubatuba, Brazil. Limpets consistently showed a proportionally larger foot on exposed boulder sides for all shores, indicating that stronger attachment is an important mechanism to deal with wave action dislodgement at a smaller scale. Shell shape also varied in the scale investigated here, with more conical (dissipative) shells occurring in exposed boulder sides in one exposed shore across time and in the other exposed shore in one year. Shell shape did not vary regarding boulder sides across time in the most sheltered shore. Although we did not assess large spatial scale effects of wave action in this study, variations of the effect of waves at small spatial scale observed for shell shape suggest that it may be modulated by the local wave exposure regime. Our work highlights the importance of wave action at small spatial scales, and may help to understand the ecological variability of limpets inhabiting rocky shores.

scholarly journals The importance of different spatial scales in determining structural and functional characteristics of deep-sea infauna communities

2013 ◽  
Vol 10 (7) ◽  
pp. 4547-4563 ◽  
Author(s):  
J. Ingels ◽  
A. Vanreusel
Keyword(s):  
Functional Diversity ◽  
Deep Sea ◽  
Spatial Ecology ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Standing Stock ◽  
Terrestrial Ecosystems ◽  
Small Scale ◽  
Functional Characteristics ◽  
Sampling Locations

Abstract. The urge to understand spatial distributions of species and communities and their causative processes has continuously instigated the development and testing of conceptual models in spatial ecology. For the deep sea, there is evidence that structural and functional characteristics of benthic communities are regulated by a multitude of biotic and environmental processes that act in concert on different spatial scales, but the spatial patterns are poorly understood compared to those for terrestrial ecosystems. Deep-sea studies generally focus on very limited scale ranges, thereby impairing our understanding of which spatial scales and associated processes are most important in driving structural and functional diversity of communities. Here, we used an extensive integrated dataset of free-living nematodes from deep-sea sediments to unravel the importance of different spatial scales in determining benthic infauna communities. Multiple-factor multivariate permutational analyses were performed on different sets of community descriptors (structure, structural and functional diversity, standing stock). The different spatial scales investigated cover two margins in the northeast Atlantic, several submarine canyons/channel/slope areas, a bathymetrical range of 700–4300 m, different sampling locations at each station, and vertical sediment profiles. The results indicated that the most important spatial scale for structural and functional diversity and standing stock variability is the smallest one; infauna communities changed substantially more with differences between sediment depth layers than with differences associated to larger geographical or bathymetrical scales. Community structure differences were greatest between stations at both margins. Important regulating ecosystem processes and the scale on which they occur are discussed. The results imply that, if we are to improve our understanding of ecosystem patterns of deep-sea infauna and the relevant processes driving their structure, structural and functional diversity, and standing stock, we must pay particular attention to the small-scale heterogeneity or patchiness and the causative mechanisms acting on that scale.

scholarly journals The importance of different spatial scales in determining structure and function of deep-sea infauna communities

2013 ◽  
Vol 10 (1) ◽  
pp. 195-232 ◽  
Author(s):  
J. Ingels ◽  
A. Vanreusel
Keyword(s):  
Spatial Scale ◽  
Deep Sea ◽  
Spatial Ecology ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Standing Stock ◽  
Small Scale ◽  
Sampling Locations ◽  
And Function ◽  
Structure Diversity

Abstract. The urge to understand spatial distributions of species and communities and their causative processes has continuously instigated the development and testing of conceptual models in spatial ecology. For the deep-sea, there is evidence that structure, diversity and function of benthic communities are regulated by a multitude of biotic and environmental processes that act in concert on different spatial scales, but the spatial patterns are poorly understood compared to those for other ecosystems. Deep-sea studies generally focus on very limited scale-ranges, thereby impairing our understanding of which spatial scales and associated processes are most important in driving diversity and ecosystem function of communities. Here, we used an extensive integrated dataset of free-living nematodes from deep-sea sediments to unravel which spatial scale is most important in determining benthic infauna communities. Multiple-factor multivariate permutational analyses were performed on different sets of community descriptors (structure, diversity, function, standing stock). The different spatial scales investigated cover two margins in the Northeast Atlantic, several submarine canyons/channel/slope areas, a bathymetrical range of 700–4300 m (represents different stations, 5–50 km apart), different sampling locations at each station (replication distances, 1–200 m), and vertical sediment profiles (cm layers). The results indicated that the most important spatial scale for diversity, functional and standing stock variability is the smallest one; infauna communities changed substantially more with differences between sediment depth layers than with differences associated to larger geographical or bathymetrical scales. Community structure differences were largest between stations at both margins. Important regulating ecosystem processes and the scale on which they occur are discussed. The results imply that, if we are to improve our understanding of ecosystem patterns of deep-sea infauna and the relevant processes driving their structure, diversity, function and standing stock, we must pay particular attention to the small-scale heterogeneity or patchiness and the causative mechanisms acting on that scale.

scholarly journals Emergent Behavior and Uncertainty in Multimodel Climate Projections of Precipitation Trends at Small Spatial Scales

2006 ◽  
Vol 19 (21) ◽  
pp. 5554-5569 ◽  
Author(s):  
P. Good ◽  
J. Lowe
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Scale Effects ◽  
Spatial Scales ◽  
Regional Scale ◽  
Emergent Behavior ◽  
Small Scale ◽  
Climate Projections ◽  
New Methods ◽  
Precipitation Trends

Abstract Aspects of model emergent behavior and uncertainty in regional- and small-scale effects of increasing CO2 on seasonal (June–August) precipitation are explored. Nineteen different climate models are studied. New methods of comparing multiple climate models reveal a clearer and more impact-relevant view of precipitation projections for the current century. First, the importance of small spatial scales in multimodel projections is demonstrated. Local trends can be much larger than or even have an opposing sign to the large-scale regional averages used in previous studies. Small-scale effects of increasing CO2 and natural internal variability both play important roles here. These small-scale features make multimodel comparisons difficult for precipitation. New methods that allow information from small spatial scales to be usefully compared across an ensemble of multiple models are presented. The analysis philosophy of this study works with statistical distributions of small-scale variations within climatological regions. A major result of this work is a set of emergent relationships coupling the small- and regional-scale effects of CO2 on precipitation trends. Within each region, a single relationship fits the ensemble of 19 different climate models. Using these relationships, a surprisingly large part of the intermodel variance in small-scale effects of CO2 is explainable simply by the intermodel variance in the regional mean (a form of pattern scaling). Different regions show distinctly different relationships. These relationships imply that regional mean results are still useful, as long as the interregional variation in their relationship with impact-relevant extreme trends is recognized. These relationships are used to present a clear but rich picture of an aspect of model uncertainty, characterized by the intermodel spread in seasonal precipitation trends, including information from small spatial scales.

scholarly journals The application of science to the management of Atlantic salmon (Salmo salar): integration across scales

1998 ◽  
Vol 55 (S1) ◽  
pp. 303-311 ◽  
Author(s):  
John D Armstrong ◽  
James WA Grant ◽  
Harvey L Forsgren ◽  
Kurt D Fausch ◽  
Richard M DeGraaf ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Life Histories ◽  
Large Scale ◽  
Scale Effects ◽  
Spatial Scales ◽  
Small Scale ◽  
Spatial And Temporal Scales ◽  
Management Plans ◽  
Broad Scale ◽  
The Way

The need for integration across spatial and temporal scales in applying science to the management of Atlantic salmon is considered. The factors that are currently believed to affect the production of anadromous adult Atlantic salmon (synthesized from recent reviews) are arranged in a hierarchy in which any given process overrides those processes at lower levels. There is not a good correlation between levels in the process hierarchy and levels in hierarchies of scale. This demonstrates the importance of integrating across scales in identifying the optimum foci for targeting management action. It is not possible to generalize on the need for integration across scales within management plans. This is because of the complex ecology of salmon, the broad range of characteristics of the systems of which they are a part, and the fact that both local scale and broad scale management can have broad scale effects. Many uncertainties remain regarding the large-scale components of the ecology of salmon, the way that small-scale mechanisms interact with life histories, and the way that different factors interact to limit production of fish. When more is understood of these processes, it is likely that generalized rules might be developed to predict the management requirements for stream systems. In the meantime, it is essential that there is good integration among managers working at different scales and it is important that management systems operating at all spatial scales include high-calibre expertise to compensate for the present paucity of general rules.

scholarly journals The Effects of Habitat Heterogeneity at Distinct Spatial Scales on Hard-Bottom-Associated Communities

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 39 ◽  
Author(s):  
Fabiane Gallucci ◽  
Ronaldo A. Christofoletti ◽  
Gustavo Fonseca ◽  
Gustavo M. Dias
Keyword(s):  
Habitat Heterogeneity ◽  
Rocky Shore ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Biotic Interactions ◽  
Habitat Diversity ◽  
Small Scale ◽  
Β Diversity ◽  
Biological Substrate ◽  
Mangrove Roots

For marine benthic communities, environmental heterogeneity at small spatial scales are mostly due to biologically produced habitat heterogeneity and biotic interactions, while at larger spatial scales environmental factors may prevails over biotic features. In this study, we investigated how community structure and β-diversity of hard-bottom-associated meio- and macrofauna varied in relation to small-scale (cm–m) changes in biological substrate (an algae “turf” dominated by the macroalgae Gelidium sp., the macroalgae Caulerpa racemosa and the sponge Hymeniacidon heliophile) in a rocky shore and in relation to larger-scale (10’s m) changes in environmental conditions of the same biological substrate (the macroalgae Bostrychia sp) in different habitats (rocky shore vs. mangrove roots). Results showed that both substrate identity and the surrounding environment were important in structuring the smaller-sized meiofauna, particularly the nematode assemblages, whereas the larger and more motile macrofauna was influenced only by larger-scale changes in the surrounding ecosystem. This implies that the macrofauna explores the environment in a larger spatial scale compared to the meiofauna, suggesting that effects of spatial heterogeneity on communities are dependent on organism size and mobility. Changes in taxa composition between environments and substrates highlight the importance of habitat diversity at different scales for maintaining the diversity of the associated fauna.

scholarly journals Post-settlement dispersal: the neglected link in maintenance of soft-sediment biodiversity

2015 ◽  
Vol 11 (2) ◽  
pp. 20140795 ◽  
Author(s):  
Conrad A. Pilditch ◽  
Sebastian Valanko ◽  
Joanna Norkko ◽  
Alf Norkko
Keyword(s):  
Human Activities ◽  
Larval Dispersal ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Larval Settlement ◽  
Small Scale ◽  
Soft Sediment ◽  
Species Pools ◽  
And Function ◽  
Metacommunity Dynamics

Seafloor integrity is threatened by disturbances owing to human activities. The capacity of the system to recover from disturbances, as well as maintain resilience and function, depends on dispersal. In soft-sediment systems, dispersal continues after larval settlement, but there are very few measurements of how far the post-settlers disperse in nature. Spatial scales of post-settlement dispersal are, however, likely to be similar to pelagic larval dispersal because of continued, frequent, small-scale dispersal over longer periods. The consequences of this dispersal may be more important for the maintenance of biodiversity and metacommunity dynamics than is pelagic larval dispersal, because of the greater size and competency of the dispersers. We argue that an increased empirical understanding of post-settlement dispersal processes is key for predicting how benthic communities will respond to local disturbances and shrinking regional species pools, with implications for monitoring, managing and conserving biodiversity.

Präzisions-Forstwirtschaft – was ist das? | Precision forestry – what's that?

2007 ◽  
Vol 158 (8) ◽  
pp. 235-242 ◽  
Author(s):  
Hans Rudolf Heinimann
Keyword(s):  
Business Processes ◽  
Spatial Scales ◽  
Supply Chain Coordination ◽  
Sensor Technology ◽  
Small Scale ◽  
Soil Physics ◽  
Coordination Problem ◽  
Precision Engineering ◽  
Precision Forestry ◽  
And Control

The term «precision forestry» was first introduced and discussed at a conference in 2001. The aims of this paper are to explore the scientific roots of the precision concept, define «precision forestry», and sketch the challenges that the implementation of this new concept may present to practitioners, educators, and researchers. The term «precision» does not mean accuracy on a small scale, but instead refers to the concurrent coordination and control of processes at spatial scales between 1 m and 100 km. Precision strives for an automatic control of processes. Precision land use differs from precision engineering by the requirements of gathering,storing and managing spatio-temporal variability of site and vegetation parameters. Practitioners will be facing the challenge of designing holistic, standardized business processes that are valid for whole networks of firms,and that follow available standards (e.g., SCOR, WoodX). There is a need to educate and train forestry professionals in the areas of business process re-engineering, computer supported management of business transactions,methods of remote sensing, sensor technology and control theory. Researchers will face the challenge of integrating plant physiology, soil physics and production sciences and solving the supply chain coordination problem (SCCP).

Sign in / Sign up

Export Citation Format

Share Document