W. H Conner | Clemson University (original) (raw)

Papers by W. H Conner

Research paper thumbnail of The Problem of Planting Louisiana Swamplands When Nutria(Myocastqr Coypu) Are Present

Research paper thumbnail of Creating Digital Coastal Watersheds: The Remote Data Acquisition Network at Bannockburn Plantation, Georgetown County …

clemson.edu

Abstract. Population growth and the resulting land use change required to support this growth is ... more Abstract. Population growth and the resulting land use change required to support this growth is occurring at a tremendous rate along the South Carolina coast. Sustainable technologies and low impact development practices can preserve hydrological and ecological function and ...

Research paper thumbnail of Monitoring Water Quality Changes in a Forested Freshwater Wetland Threatened By Salinity

Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large ... more Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large tidally-influenced or storm-driven incursions of estuarine waters that may also indicate rising sea levels associated with climate change. A coastal freshwater forested wetland in coastal South Carolina has experienced dieback of freshwater forested wetland trees due to increased salinity within the wetland. Vegetation in the wetland is transitioning from a closed canopy of common freshwater wetland trees such as bald cypress, water tupelo and swamp tupelo, to a more open canopy due to the establishment of salt tolerant grasses. The swamp is prime habitat for several wildlife species as evidenced by game cameras and amphibian recorders installed within the swamp. A team of researchers at the Baruch Institute examined a series of historical aerial images to track changes in vegetation through the years. In June 2013, several water level and conductivity sensors were installed along the salinity gradient to measure temporal variations in water level and salinity within the swamp. Microclimatic conditions were also measured and water flux at the tidally influenced watershed outlet logged. The data reveal that there is a pronounced salinity gradient from the upper reaches of the swamp to its lowest tidally influenced section. Upper reaches of the swamp are influenced primarily by incident rainfall within the watershed, while at the outlet there appears to be a complex dynamic driven by tides, local rainfall, and estuarine backwater effects.

Research paper thumbnail of Impacts of Outer Continental Shelf activities: LaFourche Parish, La. Final repot

Research paper thumbnail of Recognizing and Overcoming Difficult Site Conditions for Afforestation of Bottomland Hardwoods

Ecological Restoration, 2004

Research paper thumbnail of The use of wetlands in the Mississippi Delta for wastewater assimilation: a review

Ocean & Coastal Management, 2004

The use of wetlands for treatment of wastewaters has a number of important ecological and economi... more The use of wetlands for treatment of wastewaters has a number of important ecological and economic benefits. Adding nutrient rich treated wastewater effluent to selected coastal wetlands results in the following benefits: (1) improved effluent water quality; (2) increased accretion rates to help offset subsidence; (3) increased productivity of vegetation; and (4)

Research paper thumbnail of Above-ground productivity and litter decomposition in a tidal freshwater forested wetland on Bull Island, SC, USA

Forest Ecology and Management, 2007

Above-ground net primary productivity (NPP), decomposition of water tupelo leaves, and nutrient d... more Above-ground net primary productivity (NPP), decomposition of water tupelo leaves, and nutrient dynamics were investigated from 2000 to 2002 within a coastal, tidally influenced forested wetland on Bull Island, SC. Flooding of the island is influenced by flooding events of the Pee Dee River (PD) on the western side of the island, Big and Little Bull Creeks (BC) on the eastern side, and daily tidal fluctuations. Above-ground NPP ranged between 477 g/m 2 and 1117 g/m 2 while mean above-ground NPP was 743 g/m 2 when all data were combined regardless of growing seasons or sites. Mean annual litterfall and stemwood production were 463 g/(m 2 year) and 279 g/(m 2 year), respectively, for all three growing seasons. Analyses also showed that the 3-year average above-ground NPP was significantly higher (p < 0.0001) on the PD side (839 g/(m 2 year)) than on the BC side (647 g/(m 2 year)). In contrast, water tupelo leaves on the BC side decomposed faster (k = 2.04) than on the PD side (k = 1.59) probably due to microenvironmental factors such as temperature and moisture availability. Nutrient ratios (C:N, C:P, and N:P) indicated continuous N limitation on both sides of the island in respect to litter quality and nutrient deficiency.

Research paper thumbnail of The use of tree shelters in restoring forest species to a floodplain delta: 5-year results

Ecological Engineering, 2000

Without herbivory control, natural seed sources, and seasonal flood events, recovery of the Pen b... more Without herbivory control, natural seed sources, and seasonal flood events, recovery of the Pen branch delta in South Carolina to former conditions (prior to thermal discharge) may take many years. To assess the recovery process, seedlings of baldcypress (TuxoLtiurn distichum), water tupelo (Nyssa aquatica), swamp blackgum (Nyssa sylvatica var. b$oru), and green ash (Fraxinuspennsylucmicn) were planted in four areas of the delta in 1994. One-half of the seedlings were protected using tree shelters 1.5 m tall. Heights of seedlings were taken after planting and at the end of each growing season from 1994 to 1998. Survival at the end of 5 years ranged from 67 to 100% for seedlings in tree shelters and 2-90% for those not in tree shelters. Survival of seedlings without tree shelters was generally low, and mortality was attributed mainly to beaver damage. Although water tupelo, swamp blackgum, and green ash seedlings tended to die once clipped by beaver, 85% of the clipped baldcypress resprouted after clipping, and new sprouts grew vigorously. During year 1, height growth of tree shelter seedlings was significantly greater than non-tree shelter seedlings for all species, but once the seedling emerged from the top of the shelter, growth differences declined dramatically. Differences in height growth among areas was highly variable from year to year, and no one species tended to grow better in one area over another throughout the period. Restoration of the Pen branch delta to a baldcypress-water tupelo forest similar to the surrounding forest is possible. Baldcypress and water tupelo seem ideally suited to growing in all areas of the delta equally well, but it may take IO-20 years before the seedlings are of sufficient size to not be affected by herbivory and old enough to produce sufficient quantities of seed to maintain the forest.

Research paper thumbnail of Water Level Variability and Litterfall Productivity of Forested Freshwater Wetlands in Louisiana

American Midland Naturalist, 1992

ABSTRACT

Research paper thumbnail of Diameter Growth of Taxodium distichum (L.) Rich. and Nyssa aquatica L. From 1979-1985 in Four Louisiana Swamp Stands

American Midland Naturalist, 1992

Annual diameter growth of baldcypress and water tupelo trees in four swamp stands in S central Lo... more Annual diameter growth of baldcypress and water tupelo trees in four swamp stands in S central Louisiana were measured from 1979 to 1985. Seasonal patterns of growth were also monitored during 1979 and 1980 using vernier tree bands. Most growth occurred from late ...

Research paper thumbnail of Above-ground productivity and litter decomposition in a tidal freshwater forested wetland on Bull Island, SC, USA

Forest Ecology and Management, 2007

Research paper thumbnail of PRACTICE AND PERSPECTIVE Recognizing and Overcoming Difficult Site Conditions for Afforestation

hardwoods requires attention to site conditions, matching tree species to the site, and controlli... more hardwoods requires attention to site conditions, matching tree species to the site, and controlling weeds and herbivores in order to achieve success. In the last decade, about 370,000 acres (150,000 ha) of economically marginal farmland in the Lower Mississippi Alluvial Valley (LMAV) have been restored to bottomland hardwood forests (Stanturf and others 1998, King and Keeland 1999, Schoenholtz and others 2001). Planting of this considerable acreage is due to several federal programs, such as the Wetlands Reserve Program (WRP), that assist landowners by financing afforestation

Research paper thumbnail of Bottomland Hardwood Management Demonstrations for

This Conference Proceedings is brought to you for free and open access by the School of Agricultu... more This Conference Proceedings is brought to you for free and open access by the School of Agriculture Forestry Environmental Sciences at TigerPrints. It

Research paper thumbnail of Impact of hurricanes on forests of the Atlantic and Gulf Coasts, USA

Research paper thumbnail of A comparison of wetland tree growth response to hydrologic regime in Louisiana and South Carolina

Numerous investigations have examined the growth of wetland tree species under a variety of hydro... more Numerous investigations have examined the growth of wetland tree species under a variety of hydrologic conditions. Most studies have compared flooded versus non-flooded conditions in greenhouses or in one to a few field sites near each other or within the same region. Comparisons of wetland tree growth among widely separated areas of the country are rare. This study compared the diametet; growth of Nyssa sylva/ica var. biflora, Nyssa aqua/ica, and Taxodium dis/ichum trees from Louisiana (Gulf Coastal Plain) and South Carolina (Atlantic Coastal Plain), In both regions. individual trees were distributed along a gradient of hydrologic regimes from infrequent to permanent flooding. Nyssa sylva/ica var. biflora was restricted to periodic.ally flooded sites in both regions. Within these sites. this species showed little response to differences in mean water depth. In contrast, significant differences among hydrologic regimes were detected for N. aqua/ica in both regions. In Louisiana. pat...

Research paper thumbnail of Oil and gas use characterization, impacts, and guidelines

A nontechnical survey of oil and gas activities and their impacts on wetland, and a discussion of... more A nontechnical survey of oil and gas activities and their impacts on wetland, and a discussion of preliminary guidelines for optimizing production and minimizing impact are presented.

Research paper thumbnail of Conservation of Louisiana's coastal wetland forests. p.117-135. In Proceedings of Louisiana Natural Resources Symposium

Large-scale efforts to protect and restore coastal wetlands and the concurrent renewal of forest ... more Large-scale efforts to protect and restore coastal wetlands and the concurrent renewal of forest harvesting in cypress-tupelo swamps have brought new attention to Louisiana's coastal wetland forests in recent years. Our understanding of these coastal wetland forests has been limited by inadequate data and the lack of a comprehensive review of existing information. The importance of these forests is now being recognized and the loss and degradation of the ecosystem functions and services provided by Louisiana's coastal wetland forests is significant. Since Louisiana's coastal wetland forests are of tremendous economic, ecological, cultural, and recreational value to Louisiana, the country, and the world, the Louisiana Governor's office commissioned a Science Working Group to examine these forests and make recommendations for their conservation, protection and use. This paper summarizes the report findings and provides recommendations for what

Research paper thumbnail of The effect of sea level rise on coastal wetland forests: the Mississippi Delta, USA, as a model

Research paper thumbnail of Ecology of tidal freshwater forested wetlands of the southeastern United States

Research paper thumbnail of Processes Contributing to Resilience of Coastal Wetlands to Sea-Level Rise

Ecosystems, 2016

The objectives of this study were to identify processes that contribute to resilience of coastal ... more The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sealevel rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising sea level. When root zone contributions were removed statistically from comparisons between relative sea-level rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to sealevel rise.

Research paper thumbnail of The Problem of Planting Louisiana Swamplands When Nutria(Myocastqr Coypu) Are Present

Research paper thumbnail of Creating Digital Coastal Watersheds: The Remote Data Acquisition Network at Bannockburn Plantation, Georgetown County …

clemson.edu

Abstract. Population growth and the resulting land use change required to support this growth is ... more Abstract. Population growth and the resulting land use change required to support this growth is occurring at a tremendous rate along the South Carolina coast. Sustainable technologies and low impact development practices can preserve hydrological and ecological function and ...

Research paper thumbnail of Monitoring Water Quality Changes in a Forested Freshwater Wetland Threatened By Salinity

Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large ... more Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large tidally-influenced or storm-driven incursions of estuarine waters that may also indicate rising sea levels associated with climate change. A coastal freshwater forested wetland in coastal South Carolina has experienced dieback of freshwater forested wetland trees due to increased salinity within the wetland. Vegetation in the wetland is transitioning from a closed canopy of common freshwater wetland trees such as bald cypress, water tupelo and swamp tupelo, to a more open canopy due to the establishment of salt tolerant grasses. The swamp is prime habitat for several wildlife species as evidenced by game cameras and amphibian recorders installed within the swamp. A team of researchers at the Baruch Institute examined a series of historical aerial images to track changes in vegetation through the years. In June 2013, several water level and conductivity sensors were installed along the salinity gradient to measure temporal variations in water level and salinity within the swamp. Microclimatic conditions were also measured and water flux at the tidally influenced watershed outlet logged. The data reveal that there is a pronounced salinity gradient from the upper reaches of the swamp to its lowest tidally influenced section. Upper reaches of the swamp are influenced primarily by incident rainfall within the watershed, while at the outlet there appears to be a complex dynamic driven by tides, local rainfall, and estuarine backwater effects.

Research paper thumbnail of Impacts of Outer Continental Shelf activities: LaFourche Parish, La. Final repot

Research paper thumbnail of Recognizing and Overcoming Difficult Site Conditions for Afforestation of Bottomland Hardwoods

Ecological Restoration, 2004

Research paper thumbnail of The use of wetlands in the Mississippi Delta for wastewater assimilation: a review

Ocean & Coastal Management, 2004

The use of wetlands for treatment of wastewaters has a number of important ecological and economi... more The use of wetlands for treatment of wastewaters has a number of important ecological and economic benefits. Adding nutrient rich treated wastewater effluent to selected coastal wetlands results in the following benefits: (1) improved effluent water quality; (2) increased accretion rates to help offset subsidence; (3) increased productivity of vegetation; and (4)

Research paper thumbnail of Above-ground productivity and litter decomposition in a tidal freshwater forested wetland on Bull Island, SC, USA

Forest Ecology and Management, 2007

Above-ground net primary productivity (NPP), decomposition of water tupelo leaves, and nutrient d... more Above-ground net primary productivity (NPP), decomposition of water tupelo leaves, and nutrient dynamics were investigated from 2000 to 2002 within a coastal, tidally influenced forested wetland on Bull Island, SC. Flooding of the island is influenced by flooding events of the Pee Dee River (PD) on the western side of the island, Big and Little Bull Creeks (BC) on the eastern side, and daily tidal fluctuations. Above-ground NPP ranged between 477 g/m 2 and 1117 g/m 2 while mean above-ground NPP was 743 g/m 2 when all data were combined regardless of growing seasons or sites. Mean annual litterfall and stemwood production were 463 g/(m 2 year) and 279 g/(m 2 year), respectively, for all three growing seasons. Analyses also showed that the 3-year average above-ground NPP was significantly higher (p < 0.0001) on the PD side (839 g/(m 2 year)) than on the BC side (647 g/(m 2 year)). In contrast, water tupelo leaves on the BC side decomposed faster (k = 2.04) than on the PD side (k = 1.59) probably due to microenvironmental factors such as temperature and moisture availability. Nutrient ratios (C:N, C:P, and N:P) indicated continuous N limitation on both sides of the island in respect to litter quality and nutrient deficiency.

Research paper thumbnail of The use of tree shelters in restoring forest species to a floodplain delta: 5-year results

Ecological Engineering, 2000

Without herbivory control, natural seed sources, and seasonal flood events, recovery of the Pen b... more Without herbivory control, natural seed sources, and seasonal flood events, recovery of the Pen branch delta in South Carolina to former conditions (prior to thermal discharge) may take many years. To assess the recovery process, seedlings of baldcypress (TuxoLtiurn distichum), water tupelo (Nyssa aquatica), swamp blackgum (Nyssa sylvatica var. b$oru), and green ash (Fraxinuspennsylucmicn) were planted in four areas of the delta in 1994. One-half of the seedlings were protected using tree shelters 1.5 m tall. Heights of seedlings were taken after planting and at the end of each growing season from 1994 to 1998. Survival at the end of 5 years ranged from 67 to 100% for seedlings in tree shelters and 2-90% for those not in tree shelters. Survival of seedlings without tree shelters was generally low, and mortality was attributed mainly to beaver damage. Although water tupelo, swamp blackgum, and green ash seedlings tended to die once clipped by beaver, 85% of the clipped baldcypress resprouted after clipping, and new sprouts grew vigorously. During year 1, height growth of tree shelter seedlings was significantly greater than non-tree shelter seedlings for all species, but once the seedling emerged from the top of the shelter, growth differences declined dramatically. Differences in height growth among areas was highly variable from year to year, and no one species tended to grow better in one area over another throughout the period. Restoration of the Pen branch delta to a baldcypress-water tupelo forest similar to the surrounding forest is possible. Baldcypress and water tupelo seem ideally suited to growing in all areas of the delta equally well, but it may take IO-20 years before the seedlings are of sufficient size to not be affected by herbivory and old enough to produce sufficient quantities of seed to maintain the forest.

Research paper thumbnail of Water Level Variability and Litterfall Productivity of Forested Freshwater Wetlands in Louisiana

American Midland Naturalist, 1992

ABSTRACT

Research paper thumbnail of Diameter Growth of Taxodium distichum (L.) Rich. and Nyssa aquatica L. From 1979-1985 in Four Louisiana Swamp Stands

American Midland Naturalist, 1992

Annual diameter growth of baldcypress and water tupelo trees in four swamp stands in S central Lo... more Annual diameter growth of baldcypress and water tupelo trees in four swamp stands in S central Louisiana were measured from 1979 to 1985. Seasonal patterns of growth were also monitored during 1979 and 1980 using vernier tree bands. Most growth occurred from late ...

Research paper thumbnail of Above-ground productivity and litter decomposition in a tidal freshwater forested wetland on Bull Island, SC, USA

Forest Ecology and Management, 2007

Research paper thumbnail of PRACTICE AND PERSPECTIVE Recognizing and Overcoming Difficult Site Conditions for Afforestation

hardwoods requires attention to site conditions, matching tree species to the site, and controlli... more hardwoods requires attention to site conditions, matching tree species to the site, and controlling weeds and herbivores in order to achieve success. In the last decade, about 370,000 acres (150,000 ha) of economically marginal farmland in the Lower Mississippi Alluvial Valley (LMAV) have been restored to bottomland hardwood forests (Stanturf and others 1998, King and Keeland 1999, Schoenholtz and others 2001). Planting of this considerable acreage is due to several federal programs, such as the Wetlands Reserve Program (WRP), that assist landowners by financing afforestation

Research paper thumbnail of Bottomland Hardwood Management Demonstrations for

This Conference Proceedings is brought to you for free and open access by the School of Agricultu... more This Conference Proceedings is brought to you for free and open access by the School of Agriculture Forestry Environmental Sciences at TigerPrints. It

Research paper thumbnail of Impact of hurricanes on forests of the Atlantic and Gulf Coasts, USA

Research paper thumbnail of A comparison of wetland tree growth response to hydrologic regime in Louisiana and South Carolina

Numerous investigations have examined the growth of wetland tree species under a variety of hydro... more Numerous investigations have examined the growth of wetland tree species under a variety of hydrologic conditions. Most studies have compared flooded versus non-flooded conditions in greenhouses or in one to a few field sites near each other or within the same region. Comparisons of wetland tree growth among widely separated areas of the country are rare. This study compared the diametet; growth of Nyssa sylva/ica var. biflora, Nyssa aqua/ica, and Taxodium dis/ichum trees from Louisiana (Gulf Coastal Plain) and South Carolina (Atlantic Coastal Plain), In both regions. individual trees were distributed along a gradient of hydrologic regimes from infrequent to permanent flooding. Nyssa sylva/ica var. biflora was restricted to periodic.ally flooded sites in both regions. Within these sites. this species showed little response to differences in mean water depth. In contrast, significant differences among hydrologic regimes were detected for N. aqua/ica in both regions. In Louisiana. pat...

Research paper thumbnail of Oil and gas use characterization, impacts, and guidelines

A nontechnical survey of oil and gas activities and their impacts on wetland, and a discussion of... more A nontechnical survey of oil and gas activities and their impacts on wetland, and a discussion of preliminary guidelines for optimizing production and minimizing impact are presented.

Research paper thumbnail of Conservation of Louisiana's coastal wetland forests. p.117-135. In Proceedings of Louisiana Natural Resources Symposium

Large-scale efforts to protect and restore coastal wetlands and the concurrent renewal of forest ... more Large-scale efforts to protect and restore coastal wetlands and the concurrent renewal of forest harvesting in cypress-tupelo swamps have brought new attention to Louisiana's coastal wetland forests in recent years. Our understanding of these coastal wetland forests has been limited by inadequate data and the lack of a comprehensive review of existing information. The importance of these forests is now being recognized and the loss and degradation of the ecosystem functions and services provided by Louisiana's coastal wetland forests is significant. Since Louisiana's coastal wetland forests are of tremendous economic, ecological, cultural, and recreational value to Louisiana, the country, and the world, the Louisiana Governor's office commissioned a Science Working Group to examine these forests and make recommendations for their conservation, protection and use. This paper summarizes the report findings and provides recommendations for what

Research paper thumbnail of The effect of sea level rise on coastal wetland forests: the Mississippi Delta, USA, as a model

Research paper thumbnail of Ecology of tidal freshwater forested wetlands of the southeastern United States

Research paper thumbnail of Processes Contributing to Resilience of Coastal Wetlands to Sea-Level Rise

Ecosystems, 2016

The objectives of this study were to identify processes that contribute to resilience of coastal ... more The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sealevel rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising sea level. When root zone contributions were removed statistically from comparisons between relative sea-level rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to sealevel rise.