Thesis (Ph. D.)--Griffith University, 2004. / Title from PDF title page (viewed on Dec. 10, 2006). Includes bibliographical references (p. 226-247).

This study created an ecological spatial model, using a geographic information system, to visualize the influence of hydrochory on restoration of the three dominant wetland communities of broadleaf marsh, wetland shrub, and wet prairie across the floodplain of the Kissimmee River. Primary parameters incorporated into the model included floodplain hydrology, seed characteristics of buoyancy and dispersal rates, and species flood tolerance. S²rensen's similarity index, comparing spatial agreement among model output and observed community data, resulted in values of BLM-BB = 0.10, BLM = 0.07, WS = 0.21, and WP = 0.36. The significant discrepancies between modeled and observed community spatial coverage indicated a need for incorporation of more stochastic variables of climatic disturbances, nutrient availability, and soil characteristics. More research on species flood tolerance across smaller spatial scales is also needed, and base data incorporated into the model should also be reliable and consistent if accuracy is to be achieved. / by Stevee Kennard. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Abstract not available

Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (leaves 240-251).

Understanding energy fluxes within and between floodplain water bodies, and between rivers and their floodplains is essential for comprehending the dynamics of modern, altered river systems. Floodplain aquatic invertebrates may move between habitats deliberately (through emergence and dispersal) or through passive transport during flooding. This movement may represent a significant flux of energy and an essential food web subsidy. I assessed the usefulness of the stable isotopes of hydrogen and oxygen (D and 18O respectively) for identifying the origins and movements of macroinvertebrates in Mississippi River floodplain water bodies. I sampled water and invertebrates from the Mississippi River, intermittent and permanent floodplain wetlands, and tributaries during 2007 and 2008. Results showed consistent relationships between δD and δ18O signatures in invertebrate tissues and their home water bodies. I also investigated whether δD and δ18O could be used as a multivariate "fingerprint" to trace a captured invertebrate back to its environment of origin. Results showed that δD can be a useful tracer of the movement of floodplain invertebrates in some cases, although δ18O is likely not suitable for that purpose.

The composition and distribution of fish assemblages was examined in a floodplain lake system in the Amazon basin. Quantitative samples were collected during the 1992-1993 flooding season at Marchantaria Island, Solimoes River. A total of 25,819 specimens representing 8 orders, 30 families, 101 genera and 139 species of fish were collected. Analysis of species richness distribution among 7 vegetation strata showed that vegetated sites had higher species richness than unvegetated sites. Stands of Paspalum repens had the most diverse fish fauna. Canonical correspondence analysis (CCA) was used to investigate relationship between fish assemblages and 16 environmental variables. CCA revealed that dissolved oxygen, water transparency, water depth and aquatic vegetation structure were significantly related to fish assemblage organization. The results suggest that physiological adaptations to hypoxia and habitat complexity play a major role in the organization of these assemblages. The morphology, ontogenetic development, shape variability and deposition of otolith microincrements are described for floodplain serrasalmin fishes. Serrasalmin otoliths were similar to other ostariophysan, nevertheless their shape was species-specific. Elliptical Fourier analysis showed that Mylossoma aureum lapilli were highly variable in shape when compared to closely related species. PCA and discriminant function analysis indicated that two distinct forms of lapillus can be recognized for M. aureum, and intra-species variation was higher than inter-species variation. Otolith microincrement analysis was tested for these fishes, and microincrement deposition validation showed that Piaractus brachipomus deposits otolith increments on a daily basis. Patterns of spatial distribution, growth and mortality characteristics of larvae and juvenile were examined for M. aureum inhabiting the Marchantaria Island floodplain. Otolith-derived birth date reconstruction showed that M. aureum spawning season extended from late November to March, and peak larvae recruitment to the island occurred in mid-December. Larvae and juveniles had different spatial distributions in relation to habitat usage. Instantaneous growth coefficients (g) varied from 0.0197(d�����) to 0.265(d�����) among cohorts. Early-season cohorts had wider otolith microincrements and higher instantaneous growth coefficients than late-season cohorts. Mortality estimated by the decline of loge (abundance) regressed on age indicated that cohort-specific instantaneous mortality varied significantly among cohorts, ranging from 0.027(d�����) (2.6%/d) to 0.103(d�����) (9.7%/d). / Graduation date: 2001

A social survey of the communities living adjacent to the Pongolo river floodplain was carried out, in order to understand the perceptions of the impact of artificial flood releases on the general use of natural resources of Pongolo floodplain in terms of: general resource use, stream flow, water quality and subsistence agriculture. The results show that floodplain communities perceive that the present artificial flood releases which are intended to maintain the environmental requirements of the floodplain are not meeting their needs nor the needs of the environment. Key perceptions on environmental impacts identified are: (i) reduction in water required to maintain floodplain resources, (ii) deterioration in water quality and (iii) decrease in available floodplain land and natural resources. / Thesis (M.Env.Dev.) - University of KwaZulu-Natal, Pietermaritzburg, 2007.

I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation.

Multiple dimensions of biodiversity within and across producer and consumer guilds in the food web affect an ecosystem’s functionality and stability. Tropical and subtropical aquatic ecosystems, which are extremely diverse, have received much less attention than terrestrial ecosystems in regards to the effects of biodiversity on ecosystem functioning. We conducted a field experiment that tested for effects of macrophyte functional diversity on diversity and stability of associated fish assemblages in floodplain lakes of the Upper Paraná River floodplain, Brazil. Three levels of macrophyte functional diversity were maintained through time in five floodplain lakes and response variables included various components of fish taxonomic and functional diversity and stability. Components of functional diversity of fish assemblages were quantified using a suite of ecomorphological traits that relate to foraging and habitat use. Response variables primarily distinguished macrophyte treatments from the control. Macrophyte treatments had, on average, double the number of species and total abundance than the control treatment, but only limited effects on stability. The high diversity treatment was essentially nested within the low diversity for assemblage structure and had similar or even slightly lower levels of species richness and abundance in most cases. Gymnotiformes and young-of-year were diverse and relatively abundant in macrophyte treatments contributing to the large differences in diversity between macrophyte and control treatments. Higher fish diversity in structured habitats compared to more homogenous habitats is likely associated with increased ecomorphological diversity to exploit heterogeneous microhabitats and resources provided by the macrophytes.

Abstract not available