Geology topics

Sammy L. King

Publications and source records attributed to Sammy L. King.

At least 37 records · Page 2Linked to original sources

USGS2016

Altered hydrologic and geomorphic processes and bottomland hardwood plant communities of the lower White River Basin

Introduction The work explained in this report was conducted to assess geomorphic adjustment of the lower White River, Arkansas, to hydrologic modifications and establish forest age and community structure within selected communities within the floodplain. Also, the HEC–GeoRAS model was evaluated for predicting flood depth and duration within the floodplain. Hydrologic modeling using HEC–GeoRAS is a common way to model flooding in a floodplain. A parameterized model exists for the White River, Arkansas, based on observed flows at gauges, but its ability to reproduce current and future hydrological conditions throughout the floodplain has not been quantified. The objectives of this work are to— Identify current and historical rates of bank erosion and channel migration. Determine bank heights and channel incision along the river from Norrell lock to DeValls Bluff. Determine sedimentation rates along three sections of the floodplain (as in the Clarendon area, near St. Charles, and near Jacks Bay). Evaluate the accuracy of the HEC–GeoRAS model in predicting water depths in the floodplain. Determine stand establishment patterns of bottomland hardwoods within selected plant communities along three sections of the floodplain. This study provides baseline information on the current geomorphic and hydrologic conditions of the river and can assist in the interpretation of forest responses to past hydrologic and geomorphic processes. Understanding the implications for floodplain forests of geomorphic adjustment in the Lower Mississippi Alluvial Valley is key to managing the region’s valuable resources for a sustainable future.

Arkansas↗

USGS2016

Combining citizen science species distribution models and stable isotopes reveals migratory connectivity in the secretive Virginia rail

Stable hydrogen isotope (δD) methods for tracking animal movement are widely used yet often produce low resolution assignments. Incorporating prior knowledge of abundance, distribution or movement patterns can ameliorate this limitation, but data are lacking for most species. We demonstrate how observations reported by citizen scientists can be used to develop robust estimates of species distributions and to constrain δD assignments. We developed a Bayesian framework to refine isotopic estimates of migrant animal origins conditional on species distribution models constructed from citizen scientist observations. To illustrate this approach, we analysed the migratory connectivity of the Virginia rail Rallus limicola , a secretive and declining migratory game bird in North America. Citizen science observations enabled both estimation of sampling bias and construction of bias-corrected species distribution models. Conditioning δD assignments on these species distribution models yielded comparably high-resolution assignments. Most Virginia rails wintering across five Gulf Coast sites spent the previous summer near the Great Lakes, although a considerable minority originated from the Chesapeake Bay watershed or Prairie Pothole region of North Dakota. Conversely, the majority of migrating Virginia rails from a site in the Great Lakes most likely spent the previous winter on the Gulf Coast between Texas and Louisiana. Synthesis and applications . In this analysis, Virginia rail migratory connectivity does not fully correspond to the administrative flyways used to manage migratory birds. This example demonstrates that with the increasing availability of citizen science data to create species distribution models, our framework can produce high-resolution estimates of migratory connectivity for many animals, including cryptic species. Empirical evidence of links between seasonal habitats will help enable effective habitat management, hunting quotas and population monitoring and also highlight critical knowledge gaps.

Journal of Applied Ecology↗

USGS2016

Wetland tree transpiration modified by river-floodplain connectivity

Hydrologic connectivity provisions water and nutrient subsidies to floodplain wetlands and may be particularly important in floodplains with seasonal water deficits through its effects on soil moisture. In this study, we measured sapflow in 26 trees of two dominant floodplain forest species ( Celtis laevigata and Quercus lyrata ) at two hydrologically distinct sites in the lower White River floodplain in Arkansas, USA. Our objective was to investigate how connectivity-driven water table variations affected water use, an indicator of tree function. Meteorological variables (photosynthetically active radiation and vapor pressure deficit) were the dominant controls over water use at both sites; however, water table variations explained some site differences. At the wetter site, highest sapflow rates were during a late-season overbank flooding event, and no flood stress was apparent. At the drier site, sapflow decreased as the water table receded. The late-season flood pulse that resulted in flooding at the wetter site did not affect the water table at the drier site; accordingly, higher water use was not observed at the drier site. The species generally associated with wetter conditions ( Q. lyrata ) was more positively responsive to the flood pulse. Flood water subsidy lengthened the effective growing season, demonstrating ecological implications of hydrologic connectivity for alleviating water deficits that otherwise reduce function in this humid floodplain wetland.

Arkansas↗

USGS2016

Satellite-derived temperature data for monitoring water status in a floodplain forest of the Upper Sabine River, Texas

Decreased water availability due to hydrologic modifications, groundwater withdrawal, and climate change threaten bottomland hardwood (BLH) forest communities. We used satellite-derived (MODIS) land-surface temperature (LST) data to investigate spatial heterogeneity of canopy temperature (an indicator of plant-water status) in a floodplain forest of the upper Sabine River for 2008–2014. High LST pixels were generally further from the river and at higher topographic locations, indicating lower water-availability. Increasing rainfall-derived soil moisture corresponded with decreased heterogeneity of LST between pixels but there was weaker association between Sabine River stage and heterogeneity. Stronger dependence of LST convergence on rainfall rather than river flow suggests that some regions are less hydrologically connected to the river, and vegetation may rely on local precipitation and other contributions to the riparian aquifer to replenish soil moisture. Observed LST variations associated with hydrology encourage further investigation of the utility of this approach for monitoring forest stress, especially with considerations of climate change and continued river management.

Texas↗

USGS2016

Tree regeneration by seed in bottomland hardwood forests: A review

Bottomland hardwood forests (BLH) are found in temperate, humid regions of the southeastern US, primarily on alluvial floodplains adjacent to rivers. Altered hydrology in rivers and floodplains has caused changes in stand development and species composition of BLHs. We hypothesize that the driving mechanisms behind these changes are related to the regeneration process because of the complexity of recruitment and the vulnerability of species at that age in development. Here we review the state of our understanding regarding BLH regeneration, and identify potential bottlenecks throughout the stages of seed production, seed dispersal, germination, establishment, and survival. Our process-level understanding of regeneration by seed in BLHs is rudimentary, thus limiting our ability to predict the effects of hydrologic alterations on species composition. By focusing future research on the appropriate stages of regeneration, we can better understand the sources of forest-community transitions across the diverse range of BLH systems.

Southeastern Naturalist↗

USGS2016

Hydrologic effects on diameter growth phenology for Celtis laevigata and Quercus lyrata in the floodplain of the lower White River, Arkansas

Bottomland hardwood (BLH) forests represent an extensive wetland system in the Mississippi Alluvial Valley and southeastern USA, and it is currently undergoing widespread transition in species composition. One such transition involves increased establishment of sugarberry (Celtis laevigata), and decreased establishment of overcup oak (Quercus lyrata). The ecological mechanisms that control this transition are not well understood. We measured monthly diameter growth with dendrometer bands on 86 sugarberry and 42 overcup oak trees at eight sites in the floodplain of the White River (AR, USA) with differing hydrologic regimes. For both species, growth attenuated earlier at drier sites compared to wetter sites. Overcup oak grew slightly longer through late August, suggesting its growth period extends across both wet and dry periods. In contrast, sugarberry growth rate decreased substantially by mid-July. While these results did not necessarily indicate a mechanism for increased prominence of sugarberry, they suggest sugarberry growing season does not as much coincide with the typically drier period of late summer and may be less affected by these conditions. Overcup oak grows later into the dry season and water table conditions during this period may determine if overcup oak benefits from this relatively extended growth period.

Conference Paper↗

USGS2015

Influence of hydrologic modifications on Fraxinus pennsylvanica in the Mississippi River Alluvial Valley, USA

We used tree-ring analysis to examine radial growth response of a common, moderately flood-tolerant species (<i>Fraxinus pennsylvanica</i> Marshall) to hydrologic and climatic variability for > 40 years before and after hydrologic modifications affecting two forest stands in the Mississippi River Alluvial Valley (USA): a stand without levees below dams and a stand within a ring levee. At the stand without levees below dams, spring flood stages decreased and overall growth increased after dam construction, which we attribute to a reduction in flood stress. At the stand within a ring levee, growth responded to the elimination of overbank flooding by shifting from being positively correlated with river stage to not being correlated with river stage. In general, growth in swales was positively correlated with river stage and Palmer Drought Severity Index (an index of soil moisture) for longer periods than flats. Growth decreased after levee construction, but swales were less impacted than flats likely because of differences in elevation and soils provide higher soil moisture. Results of this study indicate that broad-scale hydrologic processes differ in their effects on the flood regime, and the effects on growth of moderately flood-tolerant species such as <i>F. pennsylvanica</i> can be mediated by local-scale factors such as topographic position, which affects soil moisture.

Bayou Cocodrie National Wildlife Refuge, White Riv↗

USGS2014

Evaluating abiotic influences on soil salinity of inland managed wetlands and agricultural croplands in a semi-arid environment

Agriculture and moist-soil management are important management techniques used on wildlife refuges to provide adequate energy for migrant waterbirds. In semi-arid systems, the accumulation of soluble salts throughout the soil profile can limit total production of wetland plants and agronomic crops and thus jeopardize meeting waterbird energy needs. This study evaluates the effect of distinct hydrologic regimes associated with moist-soil management and agricultural production on salt accumulation in a semi-arid floodplain. We hypothesized that the frequency of flooding and quantity of floodwater in a moist-soil management hydroperiod results in a less saline soil profile compared to profiles under traditional agricultural management. Findings showed that agricultural croplands differed ( p -value < 0.001, df = 9) in quantities of total soluble salts (TSS) compared to moist-soil impoundments and contained greater concentrations (TSS range = 1,160-1,750 (mg kg-1)) at depth greater than 55 cm below the surface of the profile, while moist-soil impoundments contained lower concentrations (TSS range = 307-531 (mg kg-1)) at the same depths. Increased salts in agricultural may be attributed to the lack of leaching afforded by smaller summer irrigations while larger periodic flooding events in winter and summer flood irrigations in moist-soil impoundments may serve as leaching events.

Wetlands↗

USGS2014

Multiscale habitat selection of wetland birds in the northern Gulf Coast

The spatial scale of habitat selection has become a prominent concept in ecology, but has received less attention in coastal ecology. In coastal marshes, broad-scale marsh types are defined by vegetation composition over thousands of hectares, water-level management is applied over hundreds of hectares, and fine-scale habitat is depicted by tens of meters. Individually, these scales are known to affect wetland fauna, but studies have not examined all three spatial scales simultaneously. We investigated wetland bird habitat selection at the three scales and compared single- and multiscale models. From 2009 to 2011, we surveyed marsh birds (i.e., Rallidae, bitterns, grebes), shorebirds, and wading birds in fresh and intermediate (oligohaline) coastal marsh in Louisiana and Texas, USA. Within each year, six repeated surveys of wintering, resident, and migratory breeding birds were conducted at > 100 points ( n = 304). The results revealed fine-scale factors, primarily water depth, were consistently better predictors than marsh type or management. However, 10 of 11 species had improved models with the three scales combined. Birds with a linear association with water depth were, correspondingly, most abundant with deeper fresh marsh and permanently impounded water. Conversely, intermediate marsh had a greater abundance of shallow water species, such as king rail Rallus elegans, least bittern Ixobrychus exilis, and sora Porzana carolina. These birds had quadratic relationships with water depth or no relationship. Overall, coastal birds were influenced by multiple scales corresponding with hydrological characteristics. The effects suggest the timing of drawdowns and interannual variability in spring water levels can greatly affect wetland bird abundance.

Estuaries and Coasts↗

USGS2014

Linking multi-temporal satellite imagery to coastal wetland dynamics and bird distribution

Ecosystems are characterized by dynamic ecological processes, such as flooding and fires, but spatial models are often limited to a single measurement in time. The characterization of direct, fine-scale processes affecting animals is potentially valuable for management applications, but these are difficult to quantify over broad extents. Direct predictors are also expected to improve transferability of models beyond the area of study. Here, we investigated the ability of non-static and multi-temporal habitat characteristics to predict marsh bird distributions, while testing model generality and transferability between two coastal habitats. Distribution models were developed for king rail ( Rallus elegans ), common gallinule ( Gallinula galeata ), least bittern ( Ixobrychus exilis ), and purple gallinule ( Porphyrio martinica ) in fresh and intermediate marsh types in the northern Gulf Coast of Louisiana and Texas, USA. For model development, repeated point count surveys of marsh birds were conducted from 2009 to 2011. Landsat satellite imagery was used to quantify both annual conditions and cumulative, multi-temporal habitat characteristics. We used multivariate adaptive regression splines to quantify bird-habitat relationships for fresh, intermediate, and combined marsh habitats. Multi-temporal habitat characteristics ranked as more important than single-date characteristics, as temporary water was most influential in six of eight models. Predictive power was greater for marsh type-specific models compared to general models and model transferability was poor. Birds in fresh marsh selected for annual habitat characterizations, while birds in intermediate marsh selected for cumulative wetness and heterogeneity. Our findings emphasize that dynamic ecological processes can affect species distribution and species-habitat relationships may differ with dominant landscape characteristics.

Ecological Modelling↗

USGS2014

Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak ( Quercus lyrata ) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry ( Celtis laevigata ) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually increased for several decades before declining during a drought in the late 1990s. We interpret this result as removal of flood stress following levee construction. This finding emphasizes the fact that flooding can be stressful to trees regardless of their flood tolerance and that growth in floodplain trees can be sustained provided adequate soil moisture is present, regardless of the source of soil moisture. However, future research efforts should focus on the long-term effect of hydrologic modification on stand development and on how hydrologic modifications, such as elimination of surface flooding and groundwater declines, affect the vulnerability of floodplain forests to drought.

Forest Ecology and Management↗

USGS2014

Suitability of coastal marshes as Whooping Crane (Grus americana) foraging habitat in southwest Louisiana, USA

Foraging habitat conditions (i.e., water depth, prey biomass, digestible energy density) can be a significant predictor of foraging habitat selection by wading birds. Potential foraging habitats of Whooping Cranes ( Grus americana ) using marshes include ponds and emergent marsh, but the potential prey and energy availability in these habitat types have rarely been studied. In this study, we estimated daily digestible energy density for Whooping Cranes in different marsh and microhabitat types (i.e., pond, flooded emergent marsh). Also, indicator metrics of foraging habitat suitability for Whooping Cranes were developed based on seasonal water depth, prey biomass, and digestible energy density. Seasonal water depth (cm), prey biomass (g wet weight m -2 ), and digestible energy density (kcal g -1 m -2 ) ranged from 0.0 to 50.2 ± 2.8, 0.0 to 44.8 ± 22.3, and 0.0 to 31.0 ± 15.3, respectively. With the exception of freshwater emergent marsh in summer, all available habitats were capable of supporting one Whooping Crane per 0.1 ha per day. All habitat types in the marshes had relatively higher suitability in spring and summer than in fall and winter. Our study indicates that based on general energy availability, freshwater marshes in the region can support Whooping Cranes in a relatively small area, particularly in spring and summer. In actuality, the spatial density of ponds, the flood depth of the emergent marsh, and the habitat conditions (e.g., vegetation density) between adjacent suitable habitats will constrain suitable habitat and Whooping Crane numbers.

Louisiana↗

USGS2013

Book review: The man who saved the whooping crane: The Robert Porter Allen story

Kathleen Kaska has done a remarkable job of capturing the life of Robert Porter Allen, truly one of the premier biologist/conservationists of the twentieth century. Allen, born in 1905, grew up reading outdoor adventure books and playing in the woods of northern Pennsylvania with his brother. At a young age, he was encouraged to join the Junior Audubon club and his passion for ornithology soon crystallized. He attended Lafayette College to study ornithology, but he was disinterested in academics and fared poorly. He dropped out after two years and joined the Merchant Marines. Not an auspicious beginning for such a highly respected scientist and conservationist! Soon, however, he landed a librarian job with Audubon and his diligence, acumen, and communication skills allowed him to take more and more responsibilities. He became one of the youngest Audubon sanctuary directors ever appointed, and he was also able to secure a fellowship through Cornell to work on Roseate Spoonbills ( Platalea ajaja ). Audubon later appointed him to lead their Whooping Crane ( Grus americana ) studies. Review info: The Man Who Saved the Whooping Crane. By Kathleen Kaska, 2012. ISBN: 978-0813040240, 256 pp.

Journal of Field Ornithology↗

USGS2013

Effects of hydrologic connectivity and environmental nariables on nekton assemblage in a coastal marsh system

Hydrologic connectivity and environmental variation can influence nekton assemblages in coastal ecosystems. We evaluated the effects of hydrologic connectivity (permanently connected pond: PCP; temporary connected pond: TCP), salinity, vegetation coverage, water depth and other environmental variables on seasonal nekton assemblages in freshwater, brackish, and saline marshes of the Chenier Plain, Louisiana, USA. We hypothesize that 1) nekton assemblages in PCPs have higher metrics (density, biomass, assemblage similarity) than TCPs within all marsh types and 2) no nekton species would be dominant across all marsh types. In throw traps, freshwater PCPs in Fall (36.0 ± 1.90) and Winter 2009 (43.2 ± 22.36) supported greater biomass than freshwater TCPs (Fall 2009: 9.1 ± 4.65; Winter 2009: 8.3 ± 3.42). In minnow traps, saline TCPs (5.9 ± 0.85) in Spring 2009 had higher catch per unit effort than saline PCPs (0.7 ± 0.67). Our data only partially support our first hypothesis as freshwater marsh PCPs had greater assemblage similarity than TCPs. As predicted by our second hypothesis, no nekton species dominated across all marsh types. Nekton assemblages were structured by individual species responses to the salinity gradient as well as pond habitat attributes (submerged aquatic vegetation coverage, dissolved oxygen, hydrologic connectivity).

Wetlands↗

USGS2013

Valley plugs, land use, and phytogeomorphic response: Chapter 14

Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use activities, resulting in dramatic geomorphic readjustments including the formation of valley plugs. Considerable variation in the response of abiotic processes, including surface hydrology, subsurface hydrology, and sedimentation dynamics, to channelization and the formation of valley plugs. Altered abiotic processes associated with these geomorphic features and readjustments influence biotic processes including species composition, abundance, and successional processes. Considerable interest exists for restoring altered fluvial systems and their floodplains because of their social and ecological importance. Understanding abiotic and biotic responses of channelization and valley-plug formation within the context of the watershed is essential to successful restoration. This chapter focuses on the primary causes of valley-plug formation, resulting fluvial-geomorphic responses, vegetation responses, and restoration and research needs for these systems.

Book chapter↗

USGS2013

Microhabitat selection, demography, and correlates of home range size for the King Rail ( Rallus elegans )

Animal movements and habitat selection within the home range, or microhabitat selection, can provide insights into habitat requirements, such as foraging and area requirements. The King Rail ( Rallus elegans ) is a wetland bird of high conservation concern in the United States, but little is known about its movements, habitats, or demography. King Rails ( n = 34) were captured during the 2010–2011 breeding seasons in the coastal marshes of southwest Louisiana and southeast Texas. Radio telemetry and direct habitat surveys of King Rail locations were conducted to estimate home ranges and microhabitat selection. Within home ranges, King Rails selected for greater plant species richness and comparatively greater coverage of Phragmites australis , Typha spp., and Schoenoplectus robustus . King Rails were found closer to open water compared to random locations placed 50 m from King Rail locations. Home ranges ( n = 22) varied from 0.8–32.8 ha and differed greatly among sites. Home range size did not vary by year or sex; however, increased open water, with a maximum of 29% observed in the study, was correlated with smaller home ranges. Breeding season cumulative survivorship was 89% ± 22% in 2010 and 61% ± 43% in 2011, which coincided with a drought. With an equal search effort, King Rail chicks and juveniles observed in May-June decreased from 110 in 2010 to only 16 in the drier year of 2011. The findings show King Rail used marsh with ≤ 29% open water and had smaller home ranges when open water was more abundant.

Louisiana, Texas↗

USGS2013

Effects of hydrologic connectivity on aquatic macroinvertebrate assemblages in different marsh types

Hydrologic connectivity can be an important driver of aquatic macroinvertebrate assemblages. Its effects on aquatic macroinvertebrate assemblages in coastal marshes, however, are relatively poorly studied. We evaluated the effects of lateral hydrologic connectivity (permanently connected ponds: PCPs; temporary connected ponds: TCPs), and other environmental variables on aquatic macroinvertebrate assemblages and functional feeding groups (FFGs) in freshwater, brackish, and saline marshes in Louisiana, USA. We hypothesized that (1) aquatic macroinvertebrate assemblages in PCPs would have higher assemblage metric values (density, biomass, Shannon-Wiener diversity) than TCPs and (2) the density and proportional abundance of certain FFGs (i.e. scrapers, shredders, and collectors) would be greater in freshwater marsh than brackish and saline marshes. The data in our study only partially supported our first hypothesis: while freshwater marsh PCPs had higher density and biomass than TCPs, assemblage metric values in saline TCPs were greater than saline PCPs. In freshwater TCPs, long duration of isolation limited access of macroinvertebrates from adjacent water bodies, which may have reduced assemblage metric values. However, the relatively short duration of isolation in saline TCPs provided more stable or similar habitat conditions, facilitating higher assemblage metric values. As predicted by our second hypothesis, freshwater PCPs and TCPs supported a greater density of scrapers, shredders, and collectors than brackish and saline ponds. Aquatic macroinvertebrate assemblages seem to be structured by individual taxa responses to salinity as well as pond habitat attributes.

Aquatic Biology↗

USGS2013

Seasonal comparison of aquatic macroinvertebrate assemblages in a flooded coastal freshwater marsh

Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may decrease density, taxonomic diversity, and taxa richness. The principal objectives of this study are to characterize the seasonal aquatic macroinvertebrate assemblage in a freshwater emergent marsh and compare aquatic macroinvertebrate species composition, density, and taxonomic diversity to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower seasonal density and taxonomic diversity compared to that of freshwater marsh ponds; and 2) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds. Seasonal aquatic macroinvertebrate density in freshwater emergent marsh ranged from 0 organisms/m 2 (summer 2009) to 91.1 ± 20.53 organisms/m 2 (mean ± SE; spring 2009). Density in spring was higher than in all other seasons. Taxonomic diversity did not differ and there were no unique species in the freshwater emergent marsh. Our data only partially support our first hypothesis as aquatic macroinvertebrate density and taxonomic diversity between freshwater emergent marsh and ponds did not differ in spring, fall, and winter but ponds supported higher macroinvertebrate densities than freshwater emergent marsh during summer. However, our data did not support our second hypothesis as taxa richness between freshwater emergent marsh and ponds did not statistically differ.

Louisiana↗