scholarly journals Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4441 ◽  
Author(s):  
Lorena B. Bissoli ◽  
Angelo F. Bernardino
Keyword(s):  
Spatial Variability ◽  
Secondary Production ◽  
Human Impacts ◽  
Spatial Scales ◽  
Tidal Flats ◽  
Mangrove Forests ◽  
Benthic Assemblages ◽  
Tropical Estuaries ◽  
Eastern Brazil ◽  
Habitat Differences

Tropical estuaries are highly productive and support diverse benthic assemblages within mangroves and tidal flats habitats. Determining differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support for management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition were evident, with mangrove forests being dominated by annelids (Oligochaeta and Capitellidae) whereas peracarid crustaceans were also abundant on tidal flats. Macrofaunal biomass, density and secondary production also differed between habitats and among estuaries. Those differences were related both to the composition of benthic assemblages and to random spatial variability, underscoring the importance of hierarchical sampling in estuarine ecological studies. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

scholarly journals Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil

2017 ◽  
Author(s):  
Lorena B Bissoli ◽  
Angelo F Bernardino
Keyword(s):  
Secondary Production ◽  
Human Impacts ◽  
Spatial Scales ◽  
Tidal Flats ◽  
Benthic Assemblages ◽  
Human Disturbances ◽  
Tropical Estuaries ◽  
Benthic Production ◽  
Eastern Brazil ◽  
Habitat Differences

Estuaries are highly productive and support diverse benthic assemblages, but few estimates of benthic production are available for most ecosystems. In tropical estuaries mangroves and tidal flats are typical habitats with high spatial heterogeneity of benthic macrofaunal assemblages. However, accessing differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support to management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition, biomass, density and secondary production were significant, but also varied between estuaries. Macrofaunal secondary production differed between estuaries and between tidal flat and mangrove habitats, and those differences were related to the composition of benthic assemblages. High benthic production were associated with tidal flats in estuaries with presumable less human impacts, although benthic assemblages from mangrove sediments had similar production irrespective of human disturbances. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

scholarly journals Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil

2017 ◽  
Author(s):  
Lorena B Bissoli ◽  
Angelo F Bernardino
Keyword(s):  
Secondary Production ◽  
Human Impacts ◽  
Spatial Scales ◽  
Tidal Flats ◽  
Benthic Assemblages ◽  
Human Disturbances ◽  
Tropical Estuaries ◽  
Benthic Production ◽  
Eastern Brazil ◽  
Habitat Differences

Estuaries are highly productive and support diverse benthic assemblages, but few estimates of benthic production are available for most ecosystems. In tropical estuaries mangroves and tidal flats are typical habitats with high spatial heterogeneity of benthic macrofaunal assemblages. However, accessing differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support to management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition, biomass, density and secondary production were significant, but also varied between estuaries. Macrofaunal secondary production differed between estuaries and between tidal flat and mangrove habitats, and those differences were related to the composition of benthic assemblages. High benthic production were associated with tidal flats in estuaries with presumable less human impacts, although benthic assemblages from mangrove sediments had similar production irrespective of human disturbances. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

scholarly journals Local spatial structure of forest biomass and its consequences for remote sensing of carbon stocks

2014 ◽  
Vol 11 (23) ◽  
pp. 6827-6840 ◽  
Author(s):  
M. Réjou-Méchain ◽  
H. C. Muller-Landau ◽  
M. Detto ◽  
S. C. Thomas ◽  
T. Le Toan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spatial Variability ◽  
Spatial Scales ◽  
Forest Biomass ◽  
Remote Sensing Data ◽  
Field Measurements ◽  
Forest Degradation ◽  
Forest Carbon ◽  
Mitigation Strategies ◽  
Large Plot

Abstract. Advances in forest carbon mapping have the potential to greatly reduce uncertainties in the global carbon budget and to facilitate effective emissions mitigation strategies such as REDD+ (Reducing Emissions from Deforestation and Forest Degradation). Though broad-scale mapping is based primarily on remote sensing data, the accuracy of resulting forest carbon stock estimates depends critically on the quality of field measurements and calibration procedures. The mismatch in spatial scales between field inventory plots and larger pixels of current and planned remote sensing products for forest biomass mapping is of particular concern, as it has the potential to introduce errors, especially if forest biomass shows strong local spatial variation. Here, we used 30 large (8–50 ha) globally distributed permanent forest plots to quantify the spatial variability in aboveground biomass density (AGBD in Mg ha–1) at spatial scales ranging from 5 to 250 m (0.025–6.25 ha), and to evaluate the implications of this variability for calibrating remote sensing products using simulated remote sensing footprints. We found that local spatial variability in AGBD is large for standard plot sizes, averaging 46.3% for replicate 0.1 ha subplots within a single large plot, and 16.6% for 1 ha subplots. AGBD showed weak spatial autocorrelation at distances of 20–400 m, with autocorrelation higher in sites with higher topographic variability and statistically significant in half of the sites. We further show that when field calibration plots are smaller than the remote sensing pixels, the high local spatial variability in AGBD leads to a substantial "dilution" bias in calibration parameters, a bias that cannot be removed with standard statistical methods. Our results suggest that topography should be explicitly accounted for in future sampling strategies and that much care must be taken in designing calibration schemes if remote sensing of forest carbon is to achieve its promise.

scholarly journals Carryover effects drive competitive dominance in spatially structured environments

2016 ◽  
Vol 113 (25) ◽  
pp. 6939-6944 ◽  
Author(s):  
Benjamin G. Van Allen ◽  
Volker H. W. Rudolf
Keyword(s):  
Species Interactions ◽  
Spatial Scales ◽  
Landscape Type ◽  
Habitat Differences ◽  
Natal Habitat ◽  
The Difference ◽  
Carry Over ◽  
Species Performance ◽  
Natal Habitat Effects ◽  
The Impact

Understanding how changes to the quality of habitat patches affect the distribution of species across the whole landscape is critical in our human-dominated world and changing climate. Although patterns of species’ abundances across a landscape are clearly influenced by dispersal among habitats and local species interactions, little is known about how the identity and origin of dispersers affect these patterns. Because traits of individuals are altered by experiences in their natal habitat, differences in the natal habitat of dispersers can carry over when individuals disperse to new habitats and alter their fitness and interactions with other species. We manipulated the presence or absence of such carried-over natal habitat effects for up to eight generations to examine their influence on two interacting species across multiple dispersal rates and different habitat compositions. We found that experimentally accounting for the natal habitat of dispersers significantly influenced competitive outcomes at all spatial scales and increased total community biomass within a landscape. However, the direction and magnitude of the impact of natal habitat effects was dependent upon landscape type and dispersal rate. Interestingly, effects of natal habitats increased the difference between species performance across the landscape, suggesting that natal habitat effects could alter competitive interactions to promote spatial coexistence. Given that heterogeneity in habitat quality is ubiquitous in nature, natal habitat effects are likely important drivers of spatial community structure and could promote variation in species performance, which may help facilitate spatial coexistence. The results have important implications for conservation and invasive species management.

scholarly journals Habitat associations of American badgers in southeastern British Columbia

2002 ◽  
Vol 80 (7) ◽  
pp. 1228-1239 ◽  
Author(s):  
Clayton D Apps ◽  
Nancy J Newhouse ◽  
Trevor A Kinley
Keyword(s):  
British Columbia ◽  
Forest Cover ◽  
Human Impacts ◽  
Sandy Loam ◽  
Spatial Scales ◽  
Parent Material ◽  
Habitat Associations ◽  
Vegetation Productivity ◽  
Fine Sandy Loam ◽  
Taxidea Taxus

American badgers (Taxidea taxus) are endangered in British Columbia due to habitat loss and human-caused mortality. To better understand human impacts and to promote conservation planning, we described badger habitat relationships. At two spatial scales, we analyzed selection by 12 radio-implanted resident badgers for soil composition, forest overstory, land cover, vegetation productivity, terrain, and human influence. At a broad (23.8 km2) landscape scale, soil parent-material associations were positive with glaciolacustrine and glaciofluvial and negative with colluvial. Soil-order associations were positive with brunisols and regosols and negative with podzols and luvisols. Association with fine sandy-loam texture was positive. Associations were negative with forested habitats and positive with open range, agricultural habitats, and linear disturbances. Associations were negative with elevation, slope, terrain ruggedness, and both vegetation productivity and moisture. At a fine (14.5 ha) scale, associations were positive with glaciofluvial, fine sandy-loam textured, and well-drained soils. Associations were negative with colluvial soils, forest cover, vegetation moisture, elevation, and ruggedness. Associations with open range and southern aspects were positive. The linear combination of a subset of variables could explain and predict habitat selection. At this range extent, natural conditions may restrict badger occurrence, increasing badger sensitivity to human factors that influence habitat quality and mortality.

Bidirectional connectivity in rivers and implications for watershed stability and management

2015 ◽  
Vol 72 (5) ◽  
pp. 785-795 ◽  
Author(s):  
Jonathan W. Moore
Keyword(s):  
Human Impacts ◽  
Spatial Scales ◽  
Ecological Resilience ◽  
Social Ecological Systems ◽  
Social Ecological ◽  
Challenges And Opportunities ◽  
Watershed Governance ◽  
The Stability ◽  
Natural Scale ◽  
Future Management

River networks are connected in both upstream and downstream directions on large spatial scales by movement of water, materials, and animals. Here I examine the implications of these linkages for the stability, productivity, and management of watersheds and their migratory fishes. I use simple simulations of watershed alteration to illustrate that degradation can erode the productivity and stability of both upstream and downstream fisheries. Through analysis of an existing global dataset on rivers, I found that larger rivers tend to be more fragmented than smaller rivers. I offer three challenges and opportunities for the future management of watersheds. First, given that human impacts can spread up and down rivers, there is a need to align the scales of impact assessments with the natural scale of river systems. Second, free-flowing rivers naturally dampen variability; thus, the conservation of connectivity, habitat, and biodiversity represents a key opportunity to sustain the processes that confer stability. Third, watersheds represent natural units of social–ecological systems; watershed governance would facilitate reciprocal feedbacks between people and ecosystems and enable more social–ecological resilience.

Polarimetric Radar–Based Estimates of Spatial Variability in Characteristic Sizes of Raindrops in Stratiform Rainfall

2011 ◽  
Vol 50 (12) ◽  
pp. 2514-2525 ◽  
Author(s):  
Sergey Y. Matrosov
Keyword(s):  
Spatial Variability ◽  
Spatial Scale ◽  
Spatial Scales ◽  
Cross Coupling ◽  
Mean Value ◽  
Limiting Factor ◽  
Mean Values ◽  
Measurement Mode ◽  
Mm Estimation ◽  
Stratiform Rainfall

AbstractPolarimetric X-band radar measurements of differential reflectivity ZDR in stratiform rainfall were used for retrieving mean mass-weighted raindrop diameters Dm and estimating their spatial variability δDm at different scales. The ZDR data were calibrated and corrected for differential attenuation. The results revealed greater variability in Dm for larger spatial scales. Mean values of δDm were respectively around 0.32–0.34, 0.28–0.30, and 0.24–0.26 mm at scales of 20, 10, and 4.5 km, which are representative of footprints of various spaceborne sensors. For a given spatial scale, δDm decreases when the mean value of Dm increases. At the 20-km scale the decreasing trend exhibits a factor-of-1.7 decrease of δDm when the average Dm changes from 1 to 2 mm. Estimation data suggest that this trend diminishes as the spatial scale decreases. Measurement noise and other uncertainties preclude accurate estimations of Dm variability at smaller spatial scales because for many data points estimated variability values are equal to or less than the expected retrieval errors. Even though they are important for retrievals of absolute values of Dm, the details of the drop shape–size relation did not significantly affect estimates of size spatial variability. The polarization cross coupling in simultaneous transmission–simultaneous receiving measurement mode presents another limiting factor for accurate estimations of Dm. This factor, however, was not too severe in estimations of the size variability. There are indications that tuning the differential attenuation correction scheme might balance off some possible cross-coupling ZDR bias if differential phase accumulation is less than approximately 40°.

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