Landscape allometry: from tidal channel hydraulic geometry to benthic ecology

2002 ◽  
Vol 59 (8) ◽  
pp. 1418-1427 ◽  
Author(s):  
W Gregory Hood
Keyword(s):  
Exit Time ◽  
Surface Velocity ◽  
Hydraulic Geometry ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Surface Deposit ◽  
Channel Size ◽  
Channel Form ◽  
Ecological Patterns ◽  
Patterns And Processes

The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential linkage of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of fish feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.

scholarly journals How Does Spartina alterniflora Invade in Salt Marsh in Relation to Tidal Channel Networks? Patterns and Processes

2020 ◽  
Vol 12 (18) ◽  
pp. 2983
Author(s):  
Limin Sun ◽  
Dongdong Shao ◽  
Tian Xie ◽  
Weilun Gao ◽  
Xu Ma ◽  
...  
Keyword(s):  
Spartina Alterniflora ◽  
Yellow River ◽  
Higher Order ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Channel Network ◽  
Buffer Zones ◽  
Channel Networks ◽  
Main Pathway ◽  
Patterns And Processes

Rapid invasion of Spartina alterniflora in coastal wetlands throughout the world has attracted much attention. Some field and imagery evidence has shown that the landward invasion of S. alterniflora follows the tidal channel networks as the main pathway. However, the specific patterns and processes of its invasion in salt marshes in relation to tidal channel networks are still unclear. Based on yearly satellite images from 2010 to 2018, we studied the patterning relationship between tidal channel networks and the invasion of S. alterniflora at the south bank of the Yellow River Estuary (SBYRE). At the landscape (watershed and cross-watershed) scale, we analyzed the correlation between proxies of tidal channel network drainage efficiency (unchanneled flow lengths (UFL), overmarsh path length (OPL), and tidal channels density (TCD)) and spatial distribution of S. alterniflora. At the local (channel) scale, we examined the area and number of patches of S. alterniflora in different distance buffer zones outward from the tidal channels. Our results showed that, overall, the invasion of S. alterniflora had a strong association with tidal channel networks. Watershed with higher drainage efficiency (smaller OPL) attained larger S. alterniflora area, and higher-order (third-order and above) channels tended to be the main pathway of S. alterniflora invasion. At the local scale, the total area of S. alterniflora in each distance buffer zones increased with distance within 15 m from the tidal channels, whereas the number of patches decreased with distance as expansion stabilized. Overall, the S. alterniflora area within 30 m from the tidal channels remained approximately 14% of its entire distribution throughout the invasion. The results implicated that early control of S. alterniflora invasion should pay close attention to higher-order tidal channels as the main pathway

Seafloor morphology and habitats of tidal channels in the Venice Lagoon, Italy tidal channel habitats

2020 ◽  
pp. 187-198
Author(s):  
Fantina Madricardo ◽  
Giacomo Montereale-Gavazzi ◽  
Marco Sigovini ◽  
Aleksandra Kruss ◽  
Carlotta Toso ◽  
...  
Keyword(s):  
Venice Lagoon ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Seafloor Morphology

scholarly journals Fragmented Landscape, Fragmented Knowledge: A Synthesis of Renosterveld Ecology and Conservation

2019 ◽  
Vol 46 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Emmeline N Topp ◽  
Jacqueline Loos
Keyword(s):  
Cape Floristic Region ◽  
Fragmented Landscape ◽  
Biodiversity Hotspots ◽  
Current State ◽  
Ecological Patterns ◽  
Local Patch ◽  
Populated Region ◽  
Patterns And Processes ◽  
First Time ◽  
Effective Conservation

SummaryKnowledge of ecological patterns and processes is key to effective conservation of biodiversity hotspots under threat. Renosterveld is one of the most critically endangered habitats in the biologically unique Cape Floristic Region, South Africa. For the first time, we map and synthesize the current state of knowledge on renosterveld ecology and conservation. We investigated 132 studies for the themes, locations and taxa of renosterveld research and the fragmentation, threats, recommendations and barriers to renosterveld conservation. More studies focused on plants than any other taxa (48% of articles) and are conducted mostly in larger, intact renosterveld fragments. The most commonly identified threat to renosterveld was agricultural intensification; conservation recommendations spanned improved farming practices, formal protection and local patch management. Conservation implementation has been piecemeal and has depended largely on the goodwill of landowners, which can be constrained by costs of conservation measures and a lack of suitable restoration means. Citizen science is a promising potential solution to some barriers. Fragmented knowledge in such a transformed and relatively densely populated region highlights the scale of knowledge gaps for other biodiversity hotspots and has implications for ongoing conservation work.

Hydrologic dynamics and ecosystem structure

2003 ◽  
Vol 47 (6) ◽  
pp. 17-24 ◽  
Author(s):  
I. Rodríguez-Iturbe
Keyword(s):  
Hydrological Cycle ◽  
Limiting Factor ◽  
Ecosystem Structure ◽  
Nutrient Cycles ◽  
Stochastic Fluctuation ◽  
Ecological Patterns ◽  
Probabilistic Structure ◽  
Patterns And Processes ◽  
Hydrologic Inputs ◽  
Soil Climate

Ecohydrology is the science that studies the mutual interaction between the hydrological cycle and ecosystems. Such an interaction is especially intense in water-controlled ecosystems, where water may be a limiting factor, not only because of its scarcity, but also because of its intermittent and unpredictable appearance. Hydrologic dynamics is shown to be a crucial factor for ecological patterns and processes. The probabilistic structure of soil moisture in time and space is presented as the key linkage between soil, climate and vegetation dynamics. Nutrient cycles, vegetation coexistence and plant response to environmental conditions are all intimately linked to the stochastic fluctuation of the hydrologic inputs driving an ecosystem.

scholarly journals Water quality in two Australian dryland rivers: spatial and temporal variability and the role of flow

2010 ◽  
Vol 61 (8) ◽  
pp. 864 ◽  
Author(s):  
Fran Sheldon ◽  
Christine S. Fellows
Keyword(s):  
Water Quality ◽  
Temporal Variability ◽  
Temporal Dynamics ◽  
Spatial And Temporal Variability ◽  
Quality Guidelines ◽  
Spatial And Temporal Dynamics ◽  
Flow Phase ◽  
Ecological Patterns ◽  
Patterns And Processes ◽  
Dryland Rivers

Water quality, along with hydrology, plays an important role in the spatial and temporal dynamics of a range of ecological patterns and processes in large rivers and is also often a key component of river health assessments. Geology and land use are significant drivers of water quality during flow periods while during periods of no-flow, local-scale factors such as evaporation, groundwater influence and the concentration and precipitation of compounds are important. This study explored the water quality changes in two Australian dryland rivers, the Cooper Creek (Lake Eyre Basin) and the Warrego River (Murray–Darling Basin), across different hydrological phases over several years. Water quality varied both spatially and temporally; the greatest spatial variability occurred during the no-flow phase, with temporal changes driven by flow. Concentrations of major anions and cations also varied spatially and temporally, with an overall cation dominance of calcium and magnesium and an anion dominance of bicarbonate. This bicarbonate dominance contrasts with previous data from inland lentic systems where sodium chloride was found to dominate. Such extreme spatial and temporal variability hampers successful derivation of water quality guidelines for these variable rivers and suggests such guidelines would need to be developed with respect to ‘flow phase’.

scholarly journals Macrosystems ecology: understanding ecological patterns and processes at continental scales

2014 ◽  
Vol 12 (1) ◽  
pp. 5-14 ◽  
Author(s):  
James B Heffernan ◽  
Patricia A Soranno ◽  
Michael J Angilletta ◽  
Lauren B Buckley ◽  
Daniel S Gruner ◽  
...  
Keyword(s):  
Ecological Patterns ◽  
Macrosystems Ecology ◽  
Patterns And Processes

scholarly journals A simulation study of the use of temporal occupancy for identifying core and transient species

2020 ◽  
Author(s):  
Sara Snell Taylor ◽  
Jessica R. Coyle ◽  
Ethan P. White ◽  
Allen H. Hurlbert
Keyword(s):  
Transient Species ◽  
Imperfect Detection ◽  
Heterogeneous Landscapes ◽  
Core Species ◽  
Simulation Based ◽  
Ecological Patterns ◽  
Misclassification Rates ◽  
Patterns And Processes ◽  
Source Sink

AbstractTransient species, which do not maintain self-sustaining populations in a system where they are observed, are ubiquitous in nature and their presence often impacts the interpretation of ecological patterns and processes. Identifying transient species from temporal occupancy, the proportion of time a species is observed at a given site over a time series, is subject to classification errors as a result of imperfect detection and source-sink dynamics. We use a simulation-based approach to assess how often errors in detection or classification occur in order to validate the use of temporal occupancy as a metric for inferring whether a species is a core or transient member of a community. We found that low detection increases error in the classification of core species, while high habitat heterogeneity and high detection increase error in classification of transient species. These findings confirm that temporal occupancy is a valid metric for inferring whether a species can maintain a self-sustaining population, but imperfect detection, low abundance, and highly heterogeneous landscapes may yield high misclassification rates.

Seabed mapping of tropical tidal channels, NE Brazil

2020 ◽  
Author(s):  
Andressa Lima Ferreira ◽  
Helenice Vital ◽  
Moab Gomes ◽  
Andre Aquino da Silva ◽  
Yoe Perez
Keyword(s):  
Sea Level ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Water Dynamics ◽  
Central Portion ◽  
Tidal Channel ◽  
Tidal Channels ◽  
The South ◽  
Average Width ◽  
Radar Images

<p>The Galinhos-tidal-channel system is located in the Brazilian equatorial margin, northeastern coast of Rio Grande do Norte State. The economic importance of the region began around 1600s and continues until today with salt exports, later shrimp farms, handmade fishing, oil and gas industry, ecotourism and wind energy. A spit, behind which an intricate system of tidal channels has developed, with practically absent riverine influence, characterizes the area. The integration of interferometric sonographic data (total of 4.7 km<sup>2</sup>), calibrated with sediment samples, and radar images were used to map geomorphological features on the area.  The ALOS PALSAR image, allowed to integrate the altitude information of the emerged and submerged portions, resulting in efficient method for coastal flooding areas and substrate mapping. The sonographic study allowed recognizing bedforms, which are important morphological elements that influence water and sediment discharge. Four main types of submerged geomorphic units were identified: a) 2D sandy dunes, b) 3D sandy dunes c) muddy flatbeds and d) irregular beds. Dunes were classified according to their size into small, medium and large. Bathymetric data revealed that depths from 2 to 8 m along the area. The main tidal channel Galinhos has a width of 900m, 12km long, irregular bottom, and asymmetrical margins. The Pisa Sal tidal channel has an average width of 150m and 3km long, U shaped cross-section, slight asymmetric margins and slightly irregular bottom. Deepest parts occurs close to its mouth (between 6,5m and 8m), gradually decreasing until they reach 5m on its inner portion. The Tomaz tidal channel, until to central portion has an asymmetrical bed with the highest depths on its right side reaching 7m. Its left side range from 5.5m to 6m. In the south portion, this channel becomes shallower (5m) and its asymmetry is reversed. After splitting the channel width is reduced from 260m to 140m and the bottom becomes less irregular and flat sometimes. In this portion, the highest depths reach 7m. The data made it possible to identify the regions of higher and lower altitudes using as reference the mean sea level. Altitudes throughout the region range from 0 (sea level) to 20m and come from local topographic elevation. The south portion concentrates altitudes above 10m and the lower regions are located in the central portion of the area. The central portion is the flattest and this behaviour extends over 5km to the dunes located in the Galinhos spit, when the altitudes exceed values above 10m. The Galinhos spit integrates an area with average altitude ranging from two to seven m. Flooded or wet regions were well delimited due to non-penetration or absorption of electromagnetic energy (low frequency) when it interacts with the water dynamics; however, results are better where the depth is higher than 3m.</p>

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