The Geoecology Data Base is used to assess energy-related impacts on ecosystems at regional (mult... more The Geoecology Data Base is used to assess energy-related impacts on ecosystems at regional (multi-county or multi-state) levels. The statistical analysis capabilities of SAS have been used frequently in regional analysis, as in assessing the impacts of sulfur dioxide upon natural vegetation communities or major forest tree species. The results of this application and the uses of SAS in managing the Geoecology Data Base are discussed.
The Everglades Construction Project of the South Florida Water Management District (District) wil... more The Everglades Construction Project of the South Florida Water Management District (District) will employ large constructed wetlands known as Stormwater Treatment Areas (STAs) to reduce phosphorus concentrations in runoff entering the Everglades. The District built and operated a prototype STA, the 1,545 ha Everglades Nutrient Removal Project (ENRP), to determine the efficacy of subtropical wetlands for improving regional water quality with a focus on reducing total phosphorus (TP). In five years of operation, the ENRP has consistently exceeded its performance goals of TP outflow concentrations <50 microg P/L and a 75% TP load reduction. Since August 1994, the ENRP has retained 70.3 metric tons of TP that otherwise would have entered the Everglades. When corrected for surface area and inflow TP load, TP removal efficiency was highest in the inflow buffer cell and decreased generally in a downstream fashion through the wetland. High TP removal efficiency in treatment cell 4 was attributed to superior performance of its submerged aquatic vegetation community relative to the emergent and floating macrophyte community in the other cells. Controlled experiments in the District's STA Optimization Research Program will help clarify what effect vegetation and operational conditions may have on nutrient removal in the STAs.
ABSTRACT Context Strong reciprocal interactions exist between landscape patterns and ecological p... more ABSTRACT Context Strong reciprocal interactions exist between landscape patterns and ecological processes. In wetlands, hydrology is the dominant abiotic driver of ecological processes and both controls, and is controlled, by vegetation presence and patterning. We focus on binary patterning in the Everglades ridge-slough landscape, where longitudinally connected flow, principally in sloughs, is integral to landscape function. Patterning controls discharge competence in this low-gradient peatland, with important feedbacks on hydroperiod and thus peat accretion and patch transitions. Objectives To quantitatively predict pattern effects on hydrologic connectivity and thus hydroperiod. Methods We evaluated three pattern metrics that vary in their hydrologic specificity. (1) Landscape discharge competence considers elongation and patch-type density that capture geostatistical landscape features. (2) Directional connectivity index (DCI) extracts both flow path and direction based on graph theory. (3) Least flow cost (LFC) is based on a global spatial distance algorithm strongly analogous to landscape water routing, where ridges have higher flow cost than sloughs because of their elevation and vegetation structure. Metrics were evaluated in comparison to hydroperiod estimated using a numerically intensive hydrologic model for synthetic landscapes. Fitted relationships between metrics and hydroperiod for synthetic landscapes were extrapolated to contemporary and historical maps to explore hydroperiod trends in space and time. Results Both LFC and DCI were excellent predictors of hydroperiod and useful for diagnosing how the modern landscape has reorganized in response to modified hydrology. Conclusions Metric simplicity and performance indicates potential to provide hydrologically explicit, computationally simple, and spatially independent predictions of landscape hydrology, and thus effectively measure of restoration performance.
Restoration efforts in Florida's Everglades focus on preserving and restoring this unique wet... more Restoration efforts in Florida's Everglades focus on preserving and restoring this unique wetland's natural landscape. Because most of the Everglades is a freshwater peatland, it requires surplus rainfall to remain a peatland. Restoration plans generally assume a stable climate, yet projections of altered climate over a 50-year time horizon suggest that this assumption may be inappropriate. Using a legacy regional hydrological model, we simulated combinations of a temperature rise of 1.5 °C, a ± 10 % change in rainfall, and a 0.46 m sea level rise relative to base conditions. The scenario of increased evapotranspiration and increased rainfall produced a slight increase in available water. In contrast, the more likely scenario of increased evapotranspiration and decreased rainfall lowered median water depths by 5-114 cm and shortened inundation duration periods by 5-45 %. Sea level rise increased stages and inundation duration in southern Everglades National Park. These ecolo...
It is important to understand the vulnerability of the water management system in south Florida a... more It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature,...
Surface topography of boreal peatlands is frequently hummocky. The hummocks and hollows develop f... more Surface topography of boreal peatlands is frequently hummocky. The hummocks and hollows develop from the peat and remain stable over long periods of time, even while climate and other environmental conditions change. Processes leading to these stable ...
Page 1. CLIMATE RESEARCH Clim Res Vol. 11: 109124, 1999 Published March 22 1. INTRODUCTION Asses... more Page 1. CLIMATE RESEARCH Clim Res Vol. 11: 109124, 1999 Published March 22 1. INTRODUCTION Assessments of the impact of climate change have identified the importance of integrating the ecological and the economic ...
The Geoecology Data Base is used to assess energy-related impacts on ecosystems at regional (mult... more The Geoecology Data Base is used to assess energy-related impacts on ecosystems at regional (multi-county or multi-state) levels. The statistical analysis capabilities of SAS have been used frequently in regional analysis, as in assessing the impacts of sulfur dioxide upon natural vegetation communities or major forest tree species. The results of this application and the uses of SAS in managing the Geoecology Data Base are discussed.
The Everglades Construction Project of the South Florida Water Management District (District) wil... more The Everglades Construction Project of the South Florida Water Management District (District) will employ large constructed wetlands known as Stormwater Treatment Areas (STAs) to reduce phosphorus concentrations in runoff entering the Everglades. The District built and operated a prototype STA, the 1,545 ha Everglades Nutrient Removal Project (ENRP), to determine the efficacy of subtropical wetlands for improving regional water quality with a focus on reducing total phosphorus (TP). In five years of operation, the ENRP has consistently exceeded its performance goals of TP outflow concentrations <50 microg P/L and a 75% TP load reduction. Since August 1994, the ENRP has retained 70.3 metric tons of TP that otherwise would have entered the Everglades. When corrected for surface area and inflow TP load, TP removal efficiency was highest in the inflow buffer cell and decreased generally in a downstream fashion through the wetland. High TP removal efficiency in treatment cell 4 was attributed to superior performance of its submerged aquatic vegetation community relative to the emergent and floating macrophyte community in the other cells. Controlled experiments in the District's STA Optimization Research Program will help clarify what effect vegetation and operational conditions may have on nutrient removal in the STAs.
ABSTRACT Context Strong reciprocal interactions exist between landscape patterns and ecological p... more ABSTRACT Context Strong reciprocal interactions exist between landscape patterns and ecological processes. In wetlands, hydrology is the dominant abiotic driver of ecological processes and both controls, and is controlled, by vegetation presence and patterning. We focus on binary patterning in the Everglades ridge-slough landscape, where longitudinally connected flow, principally in sloughs, is integral to landscape function. Patterning controls discharge competence in this low-gradient peatland, with important feedbacks on hydroperiod and thus peat accretion and patch transitions. Objectives To quantitatively predict pattern effects on hydrologic connectivity and thus hydroperiod. Methods We evaluated three pattern metrics that vary in their hydrologic specificity. (1) Landscape discharge competence considers elongation and patch-type density that capture geostatistical landscape features. (2) Directional connectivity index (DCI) extracts both flow path and direction based on graph theory. (3) Least flow cost (LFC) is based on a global spatial distance algorithm strongly analogous to landscape water routing, where ridges have higher flow cost than sloughs because of their elevation and vegetation structure. Metrics were evaluated in comparison to hydroperiod estimated using a numerically intensive hydrologic model for synthetic landscapes. Fitted relationships between metrics and hydroperiod for synthetic landscapes were extrapolated to contemporary and historical maps to explore hydroperiod trends in space and time. Results Both LFC and DCI were excellent predictors of hydroperiod and useful for diagnosing how the modern landscape has reorganized in response to modified hydrology. Conclusions Metric simplicity and performance indicates potential to provide hydrologically explicit, computationally simple, and spatially independent predictions of landscape hydrology, and thus effectively measure of restoration performance.
Restoration efforts in Florida's Everglades focus on preserving and restoring this unique wet... more Restoration efforts in Florida's Everglades focus on preserving and restoring this unique wetland's natural landscape. Because most of the Everglades is a freshwater peatland, it requires surplus rainfall to remain a peatland. Restoration plans generally assume a stable climate, yet projections of altered climate over a 50-year time horizon suggest that this assumption may be inappropriate. Using a legacy regional hydrological model, we simulated combinations of a temperature rise of 1.5 °C, a ± 10 % change in rainfall, and a 0.46 m sea level rise relative to base conditions. The scenario of increased evapotranspiration and increased rainfall produced a slight increase in available water. In contrast, the more likely scenario of increased evapotranspiration and decreased rainfall lowered median water depths by 5-114 cm and shortened inundation duration periods by 5-45 %. Sea level rise increased stages and inundation duration in southern Everglades National Park. These ecolo...
It is important to understand the vulnerability of the water management system in south Florida a... more It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature,...
Surface topography of boreal peatlands is frequently hummocky. The hummocks and hollows develop f... more Surface topography of boreal peatlands is frequently hummocky. The hummocks and hollows develop from the peat and remain stable over long periods of time, even while climate and other environmental conditions change. Processes leading to these stable ...
Page 1. CLIMATE RESEARCH Clim Res Vol. 11: 109124, 1999 Published March 22 1. INTRODUCTION Asses... more Page 1. CLIMATE RESEARCH Clim Res Vol. 11: 109124, 1999 Published March 22 1. INTRODUCTION Assessments of the impact of climate change have identified the importance of integrating the ecological and the economic ...
Uploads
Papers