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Randolph M. Chambers - One of the best experts on this subject based on the ideXlab platform.
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Impacts of Invasive Phragmites australis on Diamondback Terrapin Nesting in Chesapeake Bay
Estuaries and Coasts, 2018Co-Authors: Cassandra E. Cook, Allison M. Mccluskey, Randolph M. ChambersAbstract:The range expansion of exotic plant species, including the invasive reed Phragmites australis , causes widespread structural and functional changes to coastal ecosystems along the Atlantic and Gulf Coasts of North America. Native estuarine species, such as the diamondback terrapin ( Malaclemys terrapin ), are at risk of adverse effects from rapid habitat changes due to exotic invasions. Diamondback terrapins currently face population threats including by-catch mortality in crab pots, predation, and habitat loss, and populations may continue to suffer if deleterious plant invasions into preferred nesting habitats are left unchecked. We examined the extent to which Phragmites affects nesting of a breeding population of diamondback terrapins at Fisherman Island National Wildlife Refuge on the eastern shore of Virginia, where Phragmites has recently expanded into known areas of terrapin nesting. With data collected from the 2015 nesting season, we quantified the extent to which Phragmites shading could impact nest incubation temperature and determined how Phragmites density impacts the risk of rhizome invasion into nests. We conclude that Phragmites cover greater than 50% would decrease incubation temperatures of terrapin nests sufficiently to produce predominantly male hatchlings. Phragmites cover had no observed effect on root growth into simulated nests, but cover by other dune plant species explained observed trends in root growth. These results suggest that terrapins may be negatively impacted by Phragmites expansion into open nesting sites. Breeding site fidelity exhibited by terrapins and other estuarine species could limit the ability of their populations to adjust to rapid coastal expansion of invasive plant species.
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Hydrologic and chemical control of Phragmites growth in tidal marshes of SW Connecticut, USA
Marine Ecology Progress Series, 2002Co-Authors: Randolph M. Chambers, David T. Osgood, Ned KalapasevAbstract:We compared hydrology and porewater chemistry along transects in 3 tidal marshes vegetated by Spartina alterniflora and by the invasive species Phragmites australis. Relative to the Phragmites zone, the S. alterniflora zone occurred at lower tidal elevations in all 3 marshes and was characterized by greater depth of flooding and shorter periods of water-table drawdown below the soil surface. Penetration by Phragmites into the S. alterniflora zone appeared to be limited by exten- sive soil saturation at the leading edge of Phragmites growth. This mixed-species zone occurred at the intersection of the low-tide groundwater table with the soil surface and was characterized by sig- nificantly higher concentrations of porewater sulfide (739 ± 63 µM) relative to the monospecific Phragmites zone (335 ± 63 µM). Dissolved ammonium and phosphate concentrations were also sig- nificantly lower in the Phragmites zone relative to S. alterniflora and mixed-species zones of vegeta- tion. Discriminant analysis of the measured hydrologic and chemical variables identified depth of flooding, flooding frequency and duration, and sulfide concentration, as the most significant vari- ables distinguishing Phragmites stands along the estuarine salinity gradient. Together, these results indicate a greater flooding tolerance by Phragmites in marshes where porewater sulfide and salinity are lower. From a hydrologic and chemical perspective, opportunities for Phragmites invasion and expansion should be greater in oligohaline and mesohaline tidal marshes relative to polyhaline habitats. To control the growth of Phragmites in tidal marshes of management concern, both the feasibility and need for methods that increase flooding depth, frequency, salinity and/or sulfide concentrations should be considered.
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The Effects of Phragmites Removal on Nutrient Pools in a Freshwater Tidal Marsh Ecosystem
Biological Invasions, 1999Co-Authors: Laura A. Meyerson, Randolph M. Chambers, Kristiina A. VogtAbstract:Selected nitrogen and phosphorus pools in two freshwater tidal marsh ecosystems on the lower Connecticut River were measured relative to Phragmites, Typha and mixed native wetland plant cover types. For both the Chapman Pond Preserve and Chester Creek Marsh, significant differences were found between plant cover types in porewater ammonium and phosphate for some months during the 1998 growing season; porewater nitrate was always below the detection limit. At Chapman Pond, no significant differences were detected between Phragmites and Typha for plant tissue N concentrations. The standing stock of nitrogen was higher in Phragmites stands, however, owing to its greater aboveground biomass. No significant difference was found between plant cover types for total soil N at Chapman Pond, but KCl extractable ammonium was higher in the mixed cover type than Phragmites or Typha. The results of this study suggest that Phragmites is affecting nutrient pools in freshwater tidal marshes, a result that should be considered in future management design.
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Porewater chemistry associated withPhragmites andSpartina in a Connecticut tidal marsh
Wetlands, 1997Co-Authors: Randolph M. ChambersAbstract:Porewater chemistry and plant height were examined along 5 short transects extending from sections of tidal marsh dominated by the common reed Phragmites australis to those dominated by Spartina alterniflora. Phragmites was found at relatively higher tidal elevations along 4 of 5 transects; along all transects, Phragmites was growing and flowering throughout a porewater salinity range from 12 to 30 ppt. Dissolved inorganic phosphorus concentrations varied from 0 to >35 μM in both Spartina and Phragmites sections of marsh, but ammonium concentrations averaged >40 μM in zones dominated by Spartina and 400 μM, perhaps due to sulfide inhibition of nitrogen uptake for growth. The persistence of Phragmites at field conditions of high salinity and elevated sulfide concentrations suggests that hydrologic management may be insufficient to eradicate Phragmites in tidal wetlands.
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Linking the Success of Phragmites to the Alteration of Ecosystem Nutrient Cycles
Concepts and Controversies in Tidal Marsh Ecology, 1Co-Authors: Laura A. Meyerson, Kristiina A. Vogt, Randolph M. ChambersAbstract:In the United States, Phragmites australis is often viewed as a pest species because it forms monocultures that dominate a site for longer time scales than other wetland plants and because it decreases biodiversity. While research has shown that Phragmites is successful in tidal marshes where it tolerates the effects of prolonged flooding and salinity, to date there is little evidence of its influence on ecosystem-level processes. We review the literature and suggest future areas of research by regarding the specific question of whether Phragmites can dominate a site through its ability to control the cycling of limiting nutrients. Phragmites sequesters nutrients in standing live and dead biomass that either accumulates in the soil or is removed from the system by tidal flushing. Phragmites reduces light and temperature under its dense growth that decreases decomposition rates and immobilizes nutrients in long-term storage pools. Phragmites outcompetes other species for increased nutrient inputs from various anthropogenic sources. We focus in particular on two possible mechanisms which may be related to Phragmites success: Phragmites immobilizes nitrogen into forms (e.g., DON) which cannot be utilized by other species; and/or Phragmites accumulates Si and/or Al which immobilize P making it unavailable to other plants. Identifying the relative importance of these mechanisms to Phragmites expansion could assist the development of successful wetland restoration and management plans.
Thomas J. Mozdzer - One of the best experts on this subject based on the ideXlab platform.
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Evidence does not support the targeting of cryptic invaders at the subspecies level using classical biological control: the example of Phragmites
Biological Invasions, 2019Co-Authors: Erik Kiviat, Karin M. Kettenring, Laura A. Meyerson, Thomas J. Mozdzer, Warwick J. Allen, Andrew H. Baldwin, Ganesh P. Bhattarai, Hans Brix, Joshua S. Caplan, Carla LambertiniAbstract:Classical biocontrol constitutes the importation of natural enemies from a native range to control a non-native pest. This is challenging when the target organism is phylogenetically close to a sympatric non-target form. Recent papers have proposed and recommended that two European moths ( Archanara spp.) be introduced to North America to control non-native Phragmites australis australis , claiming they would not adversely affect native P. australis americanus . We assert that these papers overlooked research contradicting their conclusions and that the authors recommended release of the non-native moths despite results of their own studies indicating that attack on native Phragmites is possible after field release. Furthermore, their open-field, host-specificity tests were conducted in non-wetland fields in Switzerland using potted plants, reflecting considerably different conditions than those of North American wetlands. Also, native Phragmites in eastern North America has declined, increasing its potential vulnerability to any new stressors. Because all inadvertently introduced, established, Phragmites -specialist, herbivorous insects have done more harm to native than non-native Phragmites , native Phragmites may experience more intense herbivory than non-native Phragmites from the introduction of Archanara spp. due to demographic mechanisms (e.g., increase in density of the biocontrol agent and spillover onto alternate hosts) or because the herbivores may undergo genetic change. In addition to the risk to native Phragmites, significant biomass reduction of non-native Phragmites may decrease important ecosystem services, including soil accretion in wetlands affected by sea level rise. We strongly caution against the approval of Archanara spp. as biocontrol agents for non-native Phragmites in North America.
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Phragmites australis management in the united states 40 years of methods and outcomes
Aob Plants, 2014Co-Authors: Karin M. Kettenring, David M. Burdick, Thomas J. Mozdzer, Eric L G Hazelton, Dennis F. WhighamAbstract:Studies on invasive plant management are often short in duration and limited in the methods tested, and lack an adequate description of plant communities that replace the invader following removal. Here we present a com- prehensive review of management studies on a single species, in an effort to elucidate future directions for research in invasive plant management. We reviewed the literature on Phragmites management in North America in an effort to synthesize our understanding of management efforts, identify gaps in knowledge and improve the efficacy of man- agement. Additionally, we assessed recent ecological findings concerning Phragmites mechanisms of invasion and integrated these findings into our recommendations for more effective management. Our overall goal is to examine whether or not current management approaches can be improved and whether they promote reestablishment of native plant communities. We found: (i) little information on community-level recovery of vegetation following removal of Phragmites; and (ii) most management approaches focus on the removal of Phragmites from individual stands or groups of stands over a relatively small area. With a few exceptions, recovery studies did not monitor vege- tation for substantial durations, thus limiting adequate evaluation of the recovery trajectory. We also found that none of the recovery studies were conducted in a landscape context, even though it is now well documented that land-use patterns on adjacent habitats influence the structure and function of wetlands, including the expansion of Phragmites. We suggest that Phragmites management needs to shift to watershed-scale efforts in coastal regions, or larger man- agement units inland. In addition, management efforts should focus on restoring native plant communities, rather than simply eradicating Phragmites stands. Wetlands and watersheds should be prioritized to identify ecosystems that would benefit most from Phragmites management and those where the negative impact of management would be minimal.
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nitrogen uptake by native and invasive temperate coastal macrophytes importance of dissolved organic nitrogen
Estuaries and Coasts, 2010Co-Authors: Thomas J. Mozdzer, Joseph C Zieman, Karen J McglatheryAbstract:We investigated if the success of the invasive common reed Phragmites australis could be attributed to a competitive ability to use dissolved organic nitrogen (DON) when compared to the dominant macrophyte Spartina alterniflora in tidal wetlands. Short-term nutrient uptake experiments were performed in the laboratory on two genetic lineages of Phragmites (native and introduced to North America) and S. alterniflora. Our results provide the first evidence for direct assimilation of DON by temperate marsh plants and indicate that amino acids are assimilated intact by all plant types at similar rates. Both Phragmites lineages had significantly greater urea–N assimilation rates than S. alterniflora, and the affinity for dissolved inorganic nitrogen (DIN) species was the greatest in native Phragmites > introduced Phragmites > S. alterniflora. Field studies demonstrated uptake of both DON and DIN in similar proportion as those determined in the laboratory experiments. Based on these uptake rates, we estimate that DON has the potential to account for up to 47% of N demand for Phragmites plants, and up to 24% for S. alterniflora plants. Additionally, we suggest that differences in N uptake between native and introduced Phragmites lineages explain one mechanism for the success of the introduced type under increasingly eutrophic conditions.
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Efficacy of Imazapyr and Glyphosate in the Control of Non‐Native Phragmites australis
Restoration Ecology, 2008Co-Authors: Thomas J. Mozdzer, Curtis J. Hutto, Paul A. Clarke, Dorothy P. FieldAbstract:The cosmopolitan common reed (Phragmites australis) has been expanding into previously unoccupied wetland habitats throughout North America. This invasion by a non-native haplotype of Phragmites has become a major concern due to a reduction in plant diversity, reduction of faunal biodiversity, and changes in ecosystem structure. A randomized complete block design was used to compare the efficacy of two herbicides, glyphosate (Rodeo, Dow AgroSciences, IN, U.S.A.) and imazapyr (Habitat, BASF Corporation, NC, U.S.A.), on 1-ha Phragmites monoculture in a shallow borrow pit. Six foliar experimental treatments were applied consisting of (1) 2% glyphosate formulation, June application; (2) 2% glyphosate formulation, September application; (3) 2% imazapyr formulation, June application; (4) 2% imazapyr formulation, September application; (5) 5% imazapyr formulation, June application; and (6) 5% imazapyr, September application. Experimental plots were monitored yearly for two years after treatment. Relative importance values (RIV) were determined to assess the efficacy of herbicide treatments. We report that imazapyr foliar application is statistically superior to glyphosate in reducing Phragmites RIV, with no significant differences between the 2 and 5% formulations. Both herbicides are more effective in reducing Phragmites RIV if applied early in the growing season (June). No significant differences in non-Phragmites plant recolonization were observed between herbicide treatments over the two-year time course. These results suggest that imazapyr is superior in reducing Phragmites RIV, and that earlier applications of herbicides may be more effective on Phragmites. However, managers must note that adjacent nontarget plant species may be negatively affected by earlier treatments.
Hans Brix - One of the best experts on this subject based on the ideXlab platform.
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Evidence does not support the targeting of cryptic invaders at the subspecies level using classical biological control: the example of Phragmites
Biological Invasions, 2019Co-Authors: Erik Kiviat, Karin M. Kettenring, Laura A. Meyerson, Thomas J. Mozdzer, Warwick J. Allen, Andrew H. Baldwin, Ganesh P. Bhattarai, Hans Brix, Joshua S. Caplan, Carla LambertiniAbstract:Classical biocontrol constitutes the importation of natural enemies from a native range to control a non-native pest. This is challenging when the target organism is phylogenetically close to a sympatric non-target form. Recent papers have proposed and recommended that two European moths ( Archanara spp.) be introduced to North America to control non-native Phragmites australis australis , claiming they would not adversely affect native P. australis americanus . We assert that these papers overlooked research contradicting their conclusions and that the authors recommended release of the non-native moths despite results of their own studies indicating that attack on native Phragmites is possible after field release. Furthermore, their open-field, host-specificity tests were conducted in non-wetland fields in Switzerland using potted plants, reflecting considerably different conditions than those of North American wetlands. Also, native Phragmites in eastern North America has declined, increasing its potential vulnerability to any new stressors. Because all inadvertently introduced, established, Phragmites -specialist, herbivorous insects have done more harm to native than non-native Phragmites , native Phragmites may experience more intense herbivory than non-native Phragmites from the introduction of Archanara spp. due to demographic mechanisms (e.g., increase in density of the biocontrol agent and spillover onto alternate hosts) or because the herbivores may undergo genetic change. In addition to the risk to native Phragmites, significant biomass reduction of non-native Phragmites may decrease important ecosystem services, including soil accretion in wetlands affected by sea level rise. We strongly caution against the approval of Archanara spp. as biocontrol agents for non-native Phragmites in North America.
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large scale management of common reed Phragmites australis for paper production a case study from the liaohe delta china
Ecological Engineering, 2014Co-Authors: Hans Brix, Edward A Laws, Dechao Sun, Xigui Ding, Hongming Yuan, Guangming Zhao, Jin Wang, Shaofeng PeiAbstract:Abstract The largest Phragmites reed field in the world, with a historical area of approximately 1000 km 2 , is located in the Liaohe Delta in northeastern China. The Phragmites wetlands are extensively managed to maximize the production of reed biomass for the paper industry. Based on satellite remote sensing we estimated that the total area of the Phragmites wetlands has decreased from 857 km 2 in 2003 to 786 km 2 in 2009 to accommodate oil field infrastructure and societal developments. However, at the same time the production of Phragmites biomass used for the production of reed pulp has increased to 400,000 metric tons per year. This paper describes the great efforts that have been made to increase the Phragmites yields for the paper industry, including (1) diversion of freshwater from rivers to the Phragmites fields, (2) management of the water table, (3) harvesting and burning for pest control, and (4) seawater irrigation to rehabilitate Phragmites fields infested with weeds. The paper industry has facilitated the conservation of the Phragmites wetlands and their associated ecosystem services. Besides being a source for fiber, the wetlands provide important habitat for wildlife, sequester carbon, and create job opportunities and economic income for the local people.
Erik Kiviat - One of the best experts on this subject based on the ideXlab platform.
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Evidence does not support the targeting of cryptic invaders at the subspecies level using classical biological control: the example of Phragmites
Biological Invasions, 2019Co-Authors: Erik Kiviat, Karin M. Kettenring, Laura A. Meyerson, Thomas J. Mozdzer, Warwick J. Allen, Andrew H. Baldwin, Ganesh P. Bhattarai, Hans Brix, Joshua S. Caplan, Carla LambertiniAbstract:Classical biocontrol constitutes the importation of natural enemies from a native range to control a non-native pest. This is challenging when the target organism is phylogenetically close to a sympatric non-target form. Recent papers have proposed and recommended that two European moths ( Archanara spp.) be introduced to North America to control non-native Phragmites australis australis , claiming they would not adversely affect native P. australis americanus . We assert that these papers overlooked research contradicting their conclusions and that the authors recommended release of the non-native moths despite results of their own studies indicating that attack on native Phragmites is possible after field release. Furthermore, their open-field, host-specificity tests were conducted in non-wetland fields in Switzerland using potted plants, reflecting considerably different conditions than those of North American wetlands. Also, native Phragmites in eastern North America has declined, increasing its potential vulnerability to any new stressors. Because all inadvertently introduced, established, Phragmites -specialist, herbivorous insects have done more harm to native than non-native Phragmites , native Phragmites may experience more intense herbivory than non-native Phragmites from the introduction of Archanara spp. due to demographic mechanisms (e.g., increase in density of the biocontrol agent and spillover onto alternate hosts) or because the herbivores may undergo genetic change. In addition to the risk to native Phragmites, significant biomass reduction of non-native Phragmites may decrease important ecosystem services, including soil accretion in wetlands affected by sea level rise. We strongly caution against the approval of Archanara spp. as biocontrol agents for non-native Phragmites in North America.
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Ecosystem services of Phragmites in North America with emphasis on habitat functions
Aob Plants, 2013Co-Authors: Erik KiviatAbstract:Phragmites australis (common reed) is widespread in North America, with native and non-native haplotypes. Many ecologists and wetland managers have considered P. australis a weed with little value to the native biota or human society. I document important ecosystem services of Phragmites including support for many common and rare species of plants and animals. This paper is based on an extensive review of the ecology and natural history literature, discussions with field workers, and observations in 13 US states and one Canadian province during the past 40 years. Phragmites sequesters nutrients, heavy metals and carbon, builds and stabilizes soils, and creates self-maintaining vegetation in urban and industrial areas where many plants do not thrive. These non-habitat ecosystem services are proportional to biomass and productivity. Phragmites was widely used by Native Americans for many purposes; the most important current direct use is for the treatment of wastes. Most of the knowledge of non-habitat ecosystem services is based on studies of P. australis haplotype M (an Old World haplotype). Phragmites also has habitat functions for many organisms. These functions depend on the characteristics of the landscape, habitat, Phragmites stand, species using Phragmites and life history element. The functions that Phragmites provides for many species are optimal at lower levels of Phragmites biomass and extent of stands. Old World Phragmites, contrary to many published statements, as well as North American native Phragmites, provide valuable ecosystem services including products for human use and habitat functions for other organisms. Phragmites stands may need management (e.g. thinning, fragmentation, containment or removal) to create or maintain suitable habitat for desired species of animals and plants.
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Phragmites Management Sourcebook for the Tidal Hudson River (and beyond)
2006Co-Authors: Erik KiviatAbstract:Phragmites australis (common reed) is an invasive marsh plant spreading in many wetlands on and near the tidal Hudson River. Phragmites is generally considered a pest with low value to wildlife and threatening rare plants, but scientific documentation is ambivalent. Some organisms are favored by Phragmites invasion and some are not. Phragmites appears to have considerable value for water quality amelioration and soil stabilization. Ecological functions of Phragmites vary greatly depending on site and stand factors. Important site factors include depth and duration of flooding, salinity, soil organic matter content, and microtopography; important stand factors include Phragmites height, density, dominance, prevalence of inflorescences (tassels), vine loads, presence of trees or shrubs, stand size, and interspersion of Phragmites patches with other plant communities. Phragmites is often encouraged by, and a symptom of, underlying problems, such as siltation, nutrient loading, and hydrological alteration. Yet Phragmites does not necessarily indicate poor habitat quality. Many restoration and management projects seek to remove Phragmites despite poor understanding of its ecology, the nontarget impacts of removal, and the sustainability of alternate species. I conducted a review and synthesis of information pertinent to the ecology and management of Phragmites on the Hudson River estuary and in nearby areas. This synthesis is unique in focusing on the Hudson River, considering a wide taxonomic and functional range of Phragmites impacts, and including extensive published and unpublished data and observations. I describe Phragmites ecology, address management issues on the Hudson, outline management techniques and their nontarget impacts, and suggest how research needs can be defined. Depending on management goals, site and stand factors, the surrounding landscape, and the local biota, it may be appropriate to take no action, remove a Phragmites stand, or alter the stand to change its habitat functions and ecosystem services. An explicit and documented decision-making process should be used to justify decisions and acquire information about management outcomes that can inform subsequent management.
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Phragmites use by Native North Americans
Aquatic Botany, 2001Co-Authors: Erik Kiviat, Elizabeth HamiltonAbstract:Abstract Phragmites australis (Cav.) Trin. ex Steud. occurred in North America in pre-Columbian time but has spread greatly and become invasive in the north-central and northeastern US during the 1900s. At least 46 Native North American tribes were reported to use Phragmites historically, and we compiled statistical data from the literature on 24 of these tribes. There were approximately 75 different uses of Phragmites . Each tribe had 2–25 (mean=7.0) uses for Phragmites , of which the most frequent were: arrowshaft (17 tribes), cigarette (13), flute (12), whistle (7), pipestem (7), and matting (6). Number of uses per tribe was highest in the SouthWestern quadrant of North America, and was negatively correlated with latitude but not correlated with longitude. The apparent center of Phragmites availability and use in the SouthWestern United States is consistent with occurrence of Phragmites in pre-Columbian sediments and archaeological deposits, and at least two specialized Phragmites -using animals. The ethnobotanical importance of Phragmites should be considered in management of this plant.
Cassandra E. Cook - One of the best experts on this subject based on the ideXlab platform.
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Impacts of Invasive Phragmites australis on Diamondback Terrapin Nesting in Chesapeake Bay
Estuaries and Coasts, 2018Co-Authors: Cassandra E. Cook, Allison M. Mccluskey, Randolph M. ChambersAbstract:The range expansion of exotic plant species, including the invasive reed Phragmites australis , causes widespread structural and functional changes to coastal ecosystems along the Atlantic and Gulf Coasts of North America. Native estuarine species, such as the diamondback terrapin ( Malaclemys terrapin ), are at risk of adverse effects from rapid habitat changes due to exotic invasions. Diamondback terrapins currently face population threats including by-catch mortality in crab pots, predation, and habitat loss, and populations may continue to suffer if deleterious plant invasions into preferred nesting habitats are left unchecked. We examined the extent to which Phragmites affects nesting of a breeding population of diamondback terrapins at Fisherman Island National Wildlife Refuge on the eastern shore of Virginia, where Phragmites has recently expanded into known areas of terrapin nesting. With data collected from the 2015 nesting season, we quantified the extent to which Phragmites shading could impact nest incubation temperature and determined how Phragmites density impacts the risk of rhizome invasion into nests. We conclude that Phragmites cover greater than 50% would decrease incubation temperatures of terrapin nests sufficiently to produce predominantly male hatchlings. Phragmites cover had no observed effect on root growth into simulated nests, but cover by other dune plant species explained observed trends in root growth. These results suggest that terrapins may be negatively impacted by Phragmites expansion into open nesting sites. Breeding site fidelity exhibited by terrapins and other estuarine species could limit the ability of their populations to adjust to rapid coastal expansion of invasive plant species.