@article{greenberg_moorman_elliott_martin_hopey_caldwell_2023, title={Breeding bird abundance and species diversity greatest in high-severity wildfire patches in central hardwood forests}, volume={529}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2022.120715}, abstractNote={In 2016, mixed-severity wildfires in the southern Appalachians created a gradient of forest structures not typical following prescribed burns, providing a unique opportunity to study temporally dynamic conditions and breeding bird response. We measured forest structure and breeding bird communities across a fire-severity gradient in 3 burned and 3 unburned watersheds for 5 years (Y1-Y5). We categorized plots as unburned (NB), low- (L), moderate- (M), or high-severity (H) using a composite fire-severity index. Tree mortality increased with fire-severity category (FSC) and over time; by Y5, 7 % of trees in NB, 11 % in L, 38 % in M, and 71 % in H had died. Shrub recovery was rapid and most pronounced in H, exceeding other FSCs (70 % vs 21 %–44 %) by Y5. Total bird abundance, species richness, and diversity increased over time in H (by Y3) and M (by Y4); by Y5, these metrics were highest in H and twice as high in H as in NB. Low-severity wildfires had no detectable effects on birds. Abundance of 7 species was greatest in higher-severity FSCs; 11 species did not differ among FSC, although ovenbirds (Seiurus aurocapilla) indicated a trend of lower abundance in H. No species was limited to NB, L, or M, whereas disturbance-dependent indigo bunting (Passerina cyanea), chestnut-sided warbler (Setophaga pensylvanica), and eastern towhee (Pipilo erythrophthalmus) were primarily associated with H. Increased richness and diversity were associated with heavy tree mortality and subsequent shrub recovery in H, accompanied by an influx of disturbance-dependent species and positive or neutral responses by most other species. Results highlight the interrelated roles of fire severity and time in driving forest structure and breeding bird response. Breeding birds responded to high-severity burns similarly to silvicultural treatments with heavy canopy reduction documented in other studies, offering possible alternatives when managing for breeding bird diversity in hardwood forests.}, journal={FOREST ECOLOGY AND MANAGEMENT}, publisher={Elsevier BV}, author={Greenberg, Cathryn H. and Moorman, Christopher E. and Elliott, Katherine J. and Martin, Katherine and Hopey, Mark and Caldwell, Peter V}, year={2023}, month={Feb} }
 @article{height_martin_leggett_2023, title={Call for environmental justice amplification among ecology scholars and practitioners: A Black Ecology perspective}, url={https://doi.org/10.1002/bes2.2039}, DOI={10.1002/bes2.2039}, abstractNote={Abstract For many ecologists, who do not identify as environmental justice scholars, the idea of including environmental justice into their work may not seem intuitive. This piece provides an overview of the foundations of environmental justice as a movement and as a branch of scholarship. The authors provide suggestions for how ecologists can include this area of scholarship into their work. Through this article, the authors hope to bridge the scholarly gap between environmental justice and ecology, using the lens of Black Ecology.}, journal={The Bulletin of the Ecological Society of America}, author={Height, Tatiana C. and Martin, Katherine L. and Leggett, Zakiya H.}, year={2023}, month={Jan} }
 @article{mcquillan_hwang_martin_2023, title={Extended growing seasons and decreases in hydrologic connectivity indicate increasing water stress in humid, temperate forests}, volume={338}, ISSN={["1873-2240"]}, url={https://doi.org/10.1016/j.agrformet.2023.109525}, DOI={10.1016/j.agrformet.2023.109525}, abstractNote={Forested headwater catchments are important sources of stable and abundant freshwater resources. Interactions between vegetation and topography influence lateral hydrologic connectivity by altering shallow subsurface flow paths. This in turn influences vegetation density along those paths, and subsequent hydrologic partitioning between localized water use and subsurface flows at catchment scales. Climate change impacts on forests, and the degree to which they reshape feedbacks between evapotranspiration (ET) and hydrologic connectivity, remain unclear. To clarify the extent and drivers of changing lateral hydrologic connectivity, we assessed relative changes in upslope to downslope vegetation density using the Normalized Difference Vegetation Index (NDVI) from 1984 – 2021 in 30,044 forested catchments across the Southern Appalachian Mountains. Increasing upslope NDVI relative to downslope NDVI was used as a proxy for decreasing lateral hydrologic connectivity. We then related changes in connectivity to climate and streamflow dynamics across 28 sub-regional reference watersheds. We found decreases in the ratio of downslope to upslope NDVI in almost half of the catchments (48.5%), primarily due to increasing upslope NDVI. This indicates increasing ET upslope and a decline in lateral hydrologic subsidy to downslope given precipitation. This was also supported by faster streamflow recession and increasing ET estimates relative to precipitation in over half of reference watersheds. The strongest predictor of decreasing connectivity was growing season minimum temperature (Tmin), which increased in 88% of catchments (Mean R2 = 0.27 +/- 0.13). While Tmin is not a dominant atmospheric driver of ET, this pattern has been closely linked to lengthened growing seasons. This suggests that alteration of lateral hydrologic connectivity is mainly driven by ecophysiological responses to changing climate rather than directly by atmospheric drivers. Our results emphasize the importance of vegetation dynamics shifting hydrologic partitioning and driving water limitations even in humid, temperate forests.}, journal={AGRICULTURAL AND FOREST METEOROLOGY}, author={McQuillan, Katie A. and Hwang, Taehee and Martin, Katherine L.}, year={2023}, month={Jul} }
 @article{caldwell_martin_vose_baker_warziniack_costanza_frey_nehra_mihiar_2023, title={Forested watersheds provide the highest water quality among all land cover types, but the benefit of this ecosystem service depends on landscape context}, volume={882}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2023.163550}, abstractNote={Conversion of natural land cover can degrade water quality in water supply watersheds and increase treatment costs for Public Water Systems (PWSs), but there are few studies that have fully evaluated land cover and water quality relationships in mixed use watersheds across broad hydroclimatic settings. We related upstream land cover (forest, other natural land covers, development, and agriculture) to observed and modeled water quality across the southeastern US and specifically at 1746 PWS drinking water intake facilities. While there was considerable complexity and variability in the relationship between land cover and water quality, results suggest that Total Nitrogen (TN), Total Phosphorus (TP) and Suspended Sediment (SS) concentrations decrease significantly with increasing forest cover, and increase with increasing developed or agricultural cover. Catchments with dominant (>90 %) agricultural land cover had the greatest export rates for TN, TP, and SS based on SPARROW model estimates, followed by developed-dominant, then forest- and other-natural-dominant catchments. Variability in modeled TN, TP, and SS export rates by land cover type was driven by variability in natural background sources and catchment characteristics that affected water quality even in forest-dominated catchments. Both intake setting (i.e., run-of-river or reservoir) and upstream land cover were important determinants of water quality at PWS intakes. Of all PWS intakes, 15 % had high raw water quality, and 85 % of those were on reservoirs. Of the run-of-river intakes with high raw water quality, 75 % had at least 50 % forest land cover upstream. In addition, PWS intakes obtaining surface water supply from smaller upstream catchments may experience the largest losses of natural land cover based on projections of land cover in 2070. These results illustrate the complexity and variability in the relationship between land cover and water quality at broad scales, but also suggest that forest conservation can enhance the resilience of drinking water supplies.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Caldwell, Peter V. and Martin, Katherine L. and Vose, James M. and Baker, Justin S. and Warziniack, Travis W. and Costanza, Jennifer K. and Frey, Gregory E. and Nehra, Arpita and Mihiar, Christopher M.}, year={2023}, month={Jul} }
 @article{gay_martin_v. caldwell_emanuel_sanchez_suttles_2023, title={Riparian buffers increase future baseflow and reduce peakflows in a developing watershed}, volume={862}, ISSN={["1879-1026"]}, url={http://dx.doi.org/10.1016/j.scitotenv.2022.160834}, DOI={10.1016/j.scitotenv.2022.160834}, abstractNote={Land conversion and climate change are stressing freshwater resources. Riparian areas, streamside vegetation/forest land, are critical for regulating hydrologic processes and riparian buffers are used as adaptive management strategies for mitigating land conversion effects. However, our ability to anticipate the efficacy of current and alternative riparian buffers under changing conditions remains limited. To address this information gap, we simulated hydrologic responses for different levels of buffer protection under a future scenario of land/climate change through the year 2060. We used the Soil and Water Assessment Tool (SWAT) to project future streamflow in the Upper Neuse River watershed in North Carolina, USA. We tested the capacity of riparian buffers to mitigate the effects of future land use and climate change on daily mean streamflow under three buffer treatments: present buffer widths and fully forested 15 m and 30 m buffers throughout the basin. The treatments were tested using a combination of a future climate change scenario and landcover projections that indicated a doubling of low-intensity development between 2017 and 2060. In areas with >50 % development, the 30 m buffers were particularly effective at increasing average daily streamflow during the lowest flow events by 4 % and decreasing flow during highest flow events by 3 % compared to no buffer protection. In areas between 20 and 50 % development, both 15 m and 30 m buffers reduced low flow by 8 % with minimal effects on high flow. Results indicate that standardized buffers might be more effective at a local scale with further research needing to focus on strategic buffer placement at the watershed scale. These findings highlight a novel approach for integrating buffers into hydrologic modeling and potential for improved methodology. Understanding the effects of riparian buffers on streamflow is crucial given the pressing need to develop innovative strategies that promote the conservation of invaluable ecosystem services.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, publisher={Elsevier BV}, author={Gay, Elly T. and Martin, Katherine L. and V. Caldwell, Peter and Emanuel, Ryan E. and Sanchez, Georgina M. and Suttles, Kelly M.}, year={2023}, month={Mar} }
 @article{zhang_martin_stevenson_yao_2022, title={Equally green? Understanding the distribution of urban green infrastructure across student demographics in four public school districts in North Carolina, USA}, volume={67}, ISSN={["1610-8167"]}, url={https://doi.org/10.1016/j.ufug.2021.127434}, DOI={10.1016/j.ufug.2021.127434}, abstractNote={Green infrastructure (GI) provides a suite of ecosystem services that are widely recognized as critical to health, well-being, and sustainability on an urbanizing planet. However, the distribution of GI across urban landscapes is frequently uneven, resulting in unequal delivery of these services to low-income residents or those belonging to underserved racial/ethnic identities. While GI distribution has been identified as unequal across municipalities, we investigated whether this was true in public schoolyards within and among urban school districts. We examined schoolyards in four metropolitan areas of diverse socio-economic and demographic compositions in North Carolina, USA to determine if they provided equal exposure to GI, then compared whether this was true of the broader urban landscape. We first classified the land cover of elementary schoolyards and their neighborhoods, then used bivariate and multivariate approaches to analyze the relationships between GI (i.e. tree canopy cover and total GI) and the socioeconomic status and race/ethnicity of the schools and surrounding neighborhoods, respectively. We found that the extent of tree canopy cover and total GI in schoolyards was unrelated to the socioeconomic status and the race/ethnicity of students across the four school districts. In contrast, neighborhoods with lower socioeconomic status and larger populations of underserved race/ethnicity residents had less tree canopy cover and total GI. Although total GI was more evenly distributed in schoolyards, the extent of tree canopy cover and total GI in schoolyards was lower than that in the neighborhoods. This suggests opportunities for school districts to expand GI in schoolyards, leveraging their potential to increase ecosystem services to all children, from increased educational opportunities to improved mental, physical, and environmental well-being.}, journal={URBAN FORESTRY & URBAN GREENING}, publisher={Elsevier BV}, author={Zhang, Zhenzhen and Martin, Katherine L. and Stevenson, Kathryn T. and Yao, Yuan}, year={2022}, month={Jan} }
 @article{mcquillan_tulbure_martin_2022, title={Forest water use is increasingly decoupled from water availability even during severe drought}, volume={2}, ISSN={["1572-9761"]}, url={https://doi.org/10.1007/s10980-022-01425-9}, DOI={10.1007/s10980-022-01425-9}, abstractNote={Key to understanding forest water balances is the role of tree species regulating evapotranspiration (ET), but the synergistic impact of forest species composition, topography, and water availability on ET and how this shapes drought sensitivity across the landscape remains unclear. Our aims were to quantify (1) the effect of forest composition and topography including elevation and hillslope gradients on the relationship between ET and water availability, and (2) whether the relationship has changed over time. We used remotely sensed Landsat and MODIS ET to quantify forest ET across the Blue Ridge ecoregion of the southeastern USA. Then quantified metrics describing ET responses to water availability and trends in responses over time and assessed how these metrics varied across elevation, hillslope, and forest composition gradients. We demonstrated forest ET is becoming less constrained by water availability at the expense of lateral flow. Drought impacts on ET diverged along elevation and hillslope gradients, and that divergence was more pronounced with increasingly severe drought, indicating high elevation and drier, upslope regions tend to maintain ET rates even during extreme drought. We identified a decoupling of ET from water availability over time, and found this process was accelerated at higher elevations and in areas with more diffuse-porous trees. Given the large proportion of forests on the landscape distributed across high elevation and upslope positions, reductions in downslope water availability could be widespread, amplifying vulnerability of runoff, the health of downslope vegetation, and aquatic biodiversity.}, journal={LANDSCAPE ECOLOGY}, author={McQuillan, Katie A. and Tulbure, Mirela G. and Martin, Katherine L.}, year={2022}, month={Feb} }
 @article{bergeson_martin_doll_cutts_2022, title={Soil infiltration rates are underestimated by models in an urban watershed in central North Carolina, USA}, volume={313}, ISSN={["1095-8630"]}, url={https://doi.org/10.1016/j.jenvman.2022.115004}, DOI={10.1016/j.jenvman.2022.115004}, abstractNote={Stormwater management problems are expanding as urbanization continues and precipitation patterns are increasingly extreme. Urban soils are often more disturbed and compacted than non-urban soils, therefore, rainfall run-off estimates based on models designed for non-urban soils may not be accurate due to altered soil infiltration rates. Our objective was to quantify soil infiltration rates across an urban watershed and compare them to estimates from rainfall-runoff models commonly used in stormwater management (Horton and Green-Ampt) as well as an alternate, random-forest model created using available geospatial data. We measured infiltration rates and collected data on soil properties (texture, bulk density) and context (land use, ground cover, time since development) at 89 points across the 102 ha Walnut Creek watershed in Raleigh, North Carolina (USA). Forest land covers and forest ground covers (leaf litter) had the highest infiltration capacities; however, all of our measurements indicate that urban soils in the Walnut Creek watershed are able to absorb most precipitation events and are likely capable of infiltrating additional urban stormwater runoff. Comparisons between observations and the rainfall-runoff model estimates reveal that both underestimated urban soil infiltration rates. Despite higher than expected urban soil infiltration capacity, stormwater management remains a challenge in this urban watershed. Therefore, to reduce stormwater runoff from impervious surfaces through soil infiltration, impervious surfaces should be disconnected, especially adjacent to new development, and urban forests should be conserved. Further, because our random forest model more accurately captured watershed infiltration rates than the rainfall-runoff models, we propose this type of machine learning approach as an alternative method for informing stormwater management and prioritizing areas for impervious disconnection.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, publisher={Elsevier BV}, author={Bergeson, Chase B. and Martin, Katherine L. and Doll, Barbara and Cutts, Bethany B.}, year={2022}, month={Jul} }
 @article{zhang_stevenson_martin_2022, title={Use of nature-based schoolyards predicts students' perceptions of schoolyards as places to support learning, play, and mental health}, volume={1}, ISSN={["1469-5871"]}, url={https://doi.org/10.1080/13504622.2022.2032612}, DOI={10.1080/13504622.2022.2032612}, abstractNote={Abstract Although green schoolyards provide many benefits to children and communities, little research explores students’ perceptions of these benefits and how natural elements (e.g. gardens, trees) and associated use shape student experience. We examine the relationship between nature-based attributes, nature-based activities, and teacher-led activities with students’ perceptions of schoolyards’ benefits to self (e.g. feeling calm, good place to learn) and to community (e.g. contributions to cleaner water, increased biodiversity). We measured 199 3rd -6th grade students’ perceptions of schoolyards’ benefits from 9 schools in Raleigh, North Carolina. Overall, students viewed schoolyards positively, and recognized more benefits to self than community. We found that the relationship between the presence of nature-based attributes and students’ positive feelings was limited. Instead, we found that nature-based activities and teacher-led activities had a positive relationship with students’ positive feelings. Our findings suggest that school greening efforts need to be paired with policies and curricular practices to encourage interaction with natural elements to ensure benefits are fully realized by students. Supplemental data for this article is available online at https://doi.org/10.1080/13504622.2022.2032612 .}, number={9}, journal={ENVIRONMENTAL EDUCATION RESEARCH}, publisher={Informa UK Limited}, author={Zhang, Zhenzhen and Stevenson, Kathryn T. and Martin, Katherine L.}, year={2022}, month={Jan} }
 @article{zhang_stevenson_martin_2021, title={Exploring geographical, curricular, and demographic factors of nature use by children in urban schoolyards in Raleigh, NC, USA}, volume={65}, ISSN={["1610-8167"]}, url={https://doi.org/10.1016/j.ufug.2021.127323}, DOI={10.1016/j.ufug.2021.127323}, abstractNote={Experience in nature provides a host of benefits to children, but today’s children who live in urban environments spend less time with nature compared to previous generations. Because children spend a large amount of time at school, greening schoolyards is one strategy for providing children with more access to nature and its benefits. However, installing nature-rich spaces in schoolyards may not guarantee their use, and research is needed to understand how the physical make-up of schoolyards may interact with teacher and student-related factors to predict use of natural elements on schoolyards. We inventoried 9 urban schoolyards and surveyed an associated 199 3rd-6th grade students and 14 teachers to measure children’s awareness and use of nature-rich vs. traditional outdoor spaces as predicted by teachers’ behavior (i.e. taking students outdoors) and environmental education-related training, student demography, and schoolyard physical environment. We found that children were less aware of nature-rich spaces (gardens 69 %, woodlands 28 %) compared to traditional outdoor spaces (playgrounds 73 %, athletic fields 77 %) and spent less time there (once a month versus several times a week). However, teachers taking children outdoors (p = 0.001) and trained in environmental education (p = 0.10) positively predicted student awareness of gardens. Teacher training in environmental education was also predictive of children exploring woodlands (p = 0.04), highlighting the importance of teacher training in successful green schoolyard efforts. We provide a glimpse of schoolyards as places for urban children to access nature's benefits by studying different school factors that influence children’s nature-based activities. Simply implementing natural spaces in schoolyards cannot guarantee the use of natural spaces by children. Providing institutional support and professional development for teachers may help to enhance children's awareness of different nature-rich areas and promote nature-base activities in schoolyards.}, journal={URBAN FORESTRY & URBAN GREENING}, publisher={Elsevier BV}, author={Zhang, Zhenzhen and Stevenson, Kathryn T. and Martin, Katherine L.}, year={2021}, month={Nov} }
 @article{saia_suttles_cutts_emanuel_martin_wear_coulston_vose_2019, title={Applying Climate Change Risk Management Tools to Integrate Streamflow Projections and Social Vulnerability}, volume={5}, ISSN={1432-9840 1435-0629}, url={http://dx.doi.org/10.1007/s10021-019-00387-5}, DOI={10.1007/s10021-019-00387-5}, number={1}, journal={Ecosystems}, publisher={Springer Science and Business Media LLC}, author={Saia, Sheila M. and Suttles, Kelly M. and Cutts, Bethany B. and Emanuel, Ryan E. and Martin, Katherine L. and Wear, David N. and Coulston, John W. and Vose, James M.}, year={2019}, month={May}, pages={67–83} }
 @article{suttles_singh_vose_martin_emanuel_coulston_saia_crump_2018, title={Assessment of hydrologic vulnerability to urbanization and climate change in a rapidly changing watershed in the Southeast US}, volume={645}, ISSN={["1879-1026"]}, url={http://dx.doi.org/10.1016/j.scitotenv.2018.06.287}, DOI={10.1016/j.scitotenv.2018.06.287}, abstractNote={This study assessed the combined effects of increased urbanization and climate change on streamflow in the Yadkin-Pee Dee watershed (North Carolina, USA) and focused on the conversion from forest to urban land use, the primary land use transition occurring in the watershed. We used the Soil and Water Assessment Tool to simulate future (2050-2070) streamflow and baseflow for four combined climate and land use scenarios across the Yadkin-Pee Dee River watershed and three subwatersheds. The combined scenarios pair land use change and climate change scenarios together. Compared to the baseline, projected streamflow increased in three out of four combined scenarios and decreased in one combined scenario. Baseflow decreased in all combined scenarios, but decreases were largest in subwatersheds that lost the most forest. The effects of land use change and climate change were additive, amplifying the increases in runoff and decreases in baseflow. Streamflow was influenced more strongly by climate change than land use change. However, for baseflow the reverse was true; land use change tended to drive baseflow more than climate change. Land use change was also a stronger driver than climate in the most urban subwatershed. In the most extreme land use and climate projection the volume of the 1-day, 100 year flood nearly doubled at the watershed outlet. Our results underscore the importance of forests as hydrologic regulators buffering streamflow and baseflow from hydrologic extremes. Additionally, our results suggest that land managers and policy makers need to consider the implications of forest loss on streamflow and baseflow when planning for future urbanization and climate change adaptation options.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Suttles, Kelly M. and Singh, Nitin K. and Vose, James M. and Martin, Katherine L. and Emanuel, Ryan E. and Coulston, John W. and Saia, Sheila M. and Crump, Michael T.}, year={2018}, month={Dec}, pages={806–816} }
 @article{hwang_martin_vose_wear_miles_kim_band_2018, title={Nonstationary Hydrologic Behavior in Forested Watersheds Is Mediated by Climate‐Induced Changes in Growing Season Length and Subsequent Vegetation Growth}, volume={54}, ISSN={0043-1397 1944-7973}, url={http://dx.doi.org/10.1029/2017WR022279}, DOI={10.1029/2017WR022279}, abstractNote={Forested watersheds provide important ecosystem services through the provision of high quality freshwater, mitigation of floods, and maintenance of base flows. How alteration of these services under ongoing climate change is mediated by vegetation dynamics is not fully understood. Combining independent remote sensing based vegetation information and distributed hydrological modeling, we investigated the impact of climate‐induced vegetation dynamics on long‐term non‐stationary hydrologic behavior in two forested watersheds in the southern Appalachians. We found significant increases in precipitation‐runoff deficit (defined as annual precipitation minus annual runoff), equivalent to annual evapotranspiration plus storage changes, over the last three decades. This non‐stationary hydrologic behavior was significantly correlated with long‐term and interannual changes in growing season length and subsequent vegetation growth. These patterns in vegetation phenology were attributed primarily to minimum temperature regimes, which showed steeper and more consistent increases than temperature maxima. Using a distributed modeling framework, we also found that the long‐term non‐stationary hydrologic behavior could not be simulated unless full vegetation dynamics, including vegetation phenology and long‐term growth, were incorporated into the model. Incorporating seasonal vegetation dynamics also led to the improved simulation in streamflow dynamics, while its effect spread out through the following dormant seasons. Our study indicates that non‐stationary hydrologic behavior has been closely mediated by long‐term seasonal and structural forest canopy interaction with climate variables rather than directly driven by climatic variables. This study emphasizes the importance of understanding the ecosystem responses to ongoing climate change for predictions of future freshwater regimes.}, number={8}, journal={Water Resources Research}, publisher={American Geophysical Union (AGU)}, author={Hwang, Taehee and Martin, Katherine L. and Vose, James M. and Wear, David and Miles, Brian and Kim, Yuri and Band, Lawrence E.}, year={2018}, month={Aug}, pages={5359–5375} }
 @article{martin_emanuel_vose_2018, title={Terra incognita: The unknown risks to environmental quality posed by the spatial distribution and abundance of concentrated animal feeding operations}, volume={642}, url={https://doi.org/10.1016/j.scitotenv.2018.06.072}, DOI={10.1016/j.scitotenv.2018.06.072}, abstractNote={Concentrated animal feeding operations (CAFOs) pose wide ranging environmental risks to many parts of the US and across the globe, but datasets for CAFO risk assessments are not readily available. Within the United States, some of the greatest concentrations of CAFOs occur in North Carolina. It is also one of the only states with publicly accessible location data for classes of CAFOs that are required to obtain water quality permits from the U.S. Environmental Protection Agency (EPA); however, there are no public data sources for the large number of CAFOs that do not require EPA water quality permits. We combined public records of CAFO locations with data collected in North Carolina by the Waterkeeper and Riverkeeper Alliances to examine the distribution of both permitted and non-permitted CAFOs across the state. Over half (55%) of the state's 6646 CAFOs are located in the Coastal Plain, a low-lying region vulnerable to flooding associated with regular cyclonic and convective storms. We identified 19% of CAFOs ≤ 100 m of the nearest stream, and some as close as 15 m to the nearest stream, a common riparian buffer width for water quality management. Future climate scenarios suggest large storm events are expected to become increasingly extreme, and dry interstorm periods could lengthen. Such extremes could exacerbate the environmental impacts of CAFOs. Understanding the potential impacts of CAFO agroecosystems will require remote sensing to identify CAFOs, fieldwork to determine the extent of environmental footprints, and modeling to identify thresholds that determine environmental risk under changing conditions.}, journal={Science of The Total Environment}, publisher={Elsevier BV}, author={Martin, Katherine L. and Emanuel, Ryan E. and Vose, James M.}, year={2018}, month={Nov}, pages={887–893} }
 @article{martin_hwang_vose_coulston_wear_miles_band_2017, title={Watershed impacts of climate and land use changes depend on magnitude and land use context}, volume={10}, ISSN={1936-0584}, url={http://dx.doi.org/10.1002/eco.1870}, DOI={10.1002/eco.1870}, abstractNote={Human population growth and urban development are affecting climate, land use, and the ecosystem services provided to society, including the supply of freshwater. We investigated the effects of land use and climate change on water resources in the Yadkin–Pee Dee River Basin of North Carolina, United States. Current and projected land uses were modeled at high resolution for three watersheds representing a forested to urban land use gradient by melding the National Land Cover Dataset with data from the U.S. Forest Service Forest Inventory and Analysis. Forecasts for 2051–2060 of regional land use and climate for scenarios of low (B2) and moderately high (A1B) rates of change, coupled with multiple global circulation models (MIROC, CSIRO, and Hadley), were used to inform a distributed ecohydrological model. Our results identified increases in water yields across the study watersheds, primarily due to forecasts of increased precipitation. Climate change was a more dominant factor for future water yield relative to land use change across all land uses (forested, urban, and mixed). When land use change was high (27% of forested land use was converted to urban development), it amplified the impacts of climate change on both the magnitude and timing of water yield. Our fine‐scale (30‐m) distributed combined modeling approach of land use and climate change identified changes in watershed hydrology at scales relevant for management, emphasizing the need for modeling efforts that integrate the effects of biophysical (climate) and social economic (land use) changes on the projection of future water resource scenarios.}, number={7}, journal={Ecohydrology}, publisher={Wiley}, author={Martin, Katherine L. and Hwang, Taehee and Vose, James M. and Coulston, John W. and Wear, David N. and Miles, Brian and Band, Lawrence E.}, year={2017}, month={Jul}, pages={e1870} }
 @misc{golladay_martin_vose_wear_covich_hobbs_klepzig_likens_naiman_shearer_et al._2016, title={Achievable future conditions as a framework for guiding forest conservation and management}, volume={360}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2015.10.009}, abstractNote={We contend that traditional approaches to forest conservation and management will be inadequate given the predicted scale of social-economic and biophysical changes in the 21st century. New approaches, focused on anticipating and guiding ecological responses to change, are urgently needed to ensure the full value of forest ecosystem services for future generations. These approaches acknowledge that change is inevitable and sometimes irreversible, and that maintenance of ecosystem services depends in part on novel ecosystems, i.e., species combinations with no analog in the past. We propose that ecological responses be evaluated at landscape or regional scales using risk-based approaches to incorporate uncertainty into forest management efforts with subsequent goals for management based on Achievable Future Conditions (AFC). AFCs defined at a landscape or regional scale incorporate advancements in ecosystem management, including adaptive approaches, resilience, and desired future conditions into the context of the Anthropocene. Inherently forward looking, ACFs encompass mitigation and adaptation options to respond to scenarios of projected future biophysical, social-economic, and policy conditions which distribute risk and provide diversity of response to uncertainty. The engagement of science-management-public partnerships is critical to our risk-based approach for defining AFCs. Robust monitoring programs of forest management actions are also crucial to address uncertainty regarding species distributions and ecosystem processes. Development of regional indicators of response will also be essential to evaluate outcomes of management strategies. Our conceptual framework provides a starting point to move toward AFCs for forest management, illustrated with examples from fire and water management in the Southeastern United States. Our model is adaptive, incorporating evaluation and modification as new information becomes available and as social–ecological dynamics change. It expands on established principles of ecosystem management and best management practices (BMPs) and incorporates scenarios of future conditions. It also highlights the potential limits of existing institutional structures for defining AFCs and achieving them. In an uncertain future of rapid change and abrupt, unforeseen transitions, adjustments in management approaches will be necessary and some actions will fail. However, it is increasingly evident that the greatest risk is posed by continuing to implement strategies inconsistent with current understanding of our novel future.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Golladay, S. W. and Martin, K. L. and Vose, J. M. and Wear, D. N. and Covich, A. P. and Hobbs, R. J. and Klepzig, K. D. and Likens, G. E. and Naiman, R. J. and Shearer, A. W. and et al.}, year={2016}, month={Jan}, pages={80–96} }
 @article{vose_martin_barten_2016, title={Applications of forest hydrological science to watershed management in the 21st century}, DOI={10.1079/9781780646602.0240}, abstractNote={This chapter examines the role of forest hydrological science in the development and application of watershed management in the 21st century. It provides a brief synthesis of anticipated biophysical and socioeconomic changes expected to occur over the coming decades and discuss critical watershed science needs and management responses to maintain watershed ecosystem services in the coming decades. The chapter builds on several recent discussions on the role of ecohydrology in addressing water resource challenges now and in the future. The examples focus on forest watersheds in the southern US forests, as the complex mixture of public and private forest land ownership creates substantial challenges for watershed management at larger spatial scales. Despite the focus on the southern USA, the general principles are applicable to forest watersheds across the globe.}, journal={Forest Hydrology: Processes, Management and Assessment}, author={Vose, J. M. and Martin, Katherine and Barten, P. K.}, year={2016}, pages={240–253} }
 @article{hurteau_liang_martin_north_koch_hungate_2016, title={Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests}, volume={26}, ISSN={1051-0761}, url={http://dx.doi.org/10.1890/15-0337}, DOI={10.1890/15-0337}, abstractNote={Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three treatments (control, thin-only, and thin and burn) with and without the occurrence of wildfire. We evaluated how two different probabilities of wildfire occurrence, 1% and 2% per year, might alter the carbon balance of treatments. In the absence of wildfire, we found that thinning and burning treatments initially reduced total ecosystem carbon (TEC) and increased net ecosystem carbon balance (NECB). In the presence of wildfire, the thin and burn treatment TEC surpassed that of the control in year 40 at 2%/yr wildfire probability, and in year 51 at 1%/yr wildfire probability. NECB in the presence of wildfire showed a similar response to the no-wildfire scenarios: both thin-only and thin and burn treatments increased the C sink. Treatments increased TEC by reducing both mean wildfire severity and its variability. While the carbon balance of treatments may differ in more productive forest types, the carbon balance benefits from restoring forest structure and fire in southwestern ponderosa pine forests are clear.}, number={2}, journal={Ecological Applications}, publisher={Wiley}, author={Hurteau, Matthew D. and Liang, Shuang and Martin, Katherine L. and North, Malcolm P. and Koch, George W. and Hungate, Bruce A.}, year={2016}, month={Mar}, pages={382–391} }
 @article{martin_hurteau_hungate_koch_north_2015, title={Carbon Tradeoffs of Restoration and Provision of Endangered Species Habitat in a Fire-Maintained Forest}, volume={18}, ISSN={1432-9840 1435-0629}, url={http://dx.doi.org/10.1007/S10021-014-9813-1}, DOI={10.1007/S10021-014-9813-1}, number={1}, journal={Ecosystems}, publisher={Springer Science and Business Media LLC}, author={Martin, Katherine L. and Hurteau, Matthew D. and Hungate, Bruce A. and Koch, George W. and North, Malcolm P.}, year={2015}, pages={76–88} }
 @article{hurteau_bradford_fulé_taylor_martin_2014, title={Climate change, fire management, and ecological services in the southwestern US}, volume={327}, ISSN={0378-1127}, url={http://dx.doi.org/10.1016/j.foreco.2013.08.007}, DOI={10.1016/j.foreco.2013.08.007}, abstractNote={The diverse forest types of the southwestern US are inseparable from fire. Across climate zones in California, Nevada, Arizona, and New Mexico, fire suppression has left many forest types out of sync with their historic fire regimes. As a result, high fuel loads place them at risk of severe fire, particularly as fire activity increases due to climate change. A legacy of fire exclusion coupled with a warming climate has led to increasingly large and severe wildfires in many southwest forest types. Climate change projections include an extended fire season length due to earlier snowmelt and a general drying trend due to rising temperatures. This suggests the future will be warmer and drier regardless of changes in precipitation. Hotter, drier conditions are likely to increase forest flammability, at least initially. Changes in climate alone have the potential to alter the distribution of vegetation types within the region, and climate-driven shifts in vegetation distribution are likely to be accelerated when coupled with stand-replacing fire. Regardless of the rate of change, the interaction of climate and fire and their effects on Southwest ecosystems will alter the provisioning of ecosystem services, including carbon storage and biodiversity. Interactions between climate, fire, and vegetation growth provide a source of great uncertainty in projecting future fire activity in the region, as post-fire forest recovery is strongly influenced by climate and subsequent fire frequency. Severe fire can be mitigated with fuels management including prescribed fire, thinning, and wildfire management, but new strategies are needed to ensure the effectiveness of treatments across landscapes. We review the current understanding of the relationship between fire and climate in the Southwest, both historical and projected. We then discuss the potential implications of climate change for fire management and examine the potential effects of climate change and fire on ecosystem services. We conclude with an assessment of the role of fire management in an increasingly flammable Southwest.}, journal={Forest Ecology and Management}, publisher={Elsevier BV}, author={Hurteau, Matthew D. and Bradford, John B. and Fulé, Peter Z. and Taylor, Alan H. and Martin, Katherine L.}, year={2014}, month={Sep}, pages={280–289} }
 @article{martin_goebel_2013, title={The foundation species influence of eastern hemlock (Tsuga canadensis) on biodiversity and ecosystem function on the Unglaciated Allegheny Plateau}, volume={289}, ISSN={0378-1127}, url={http://dx.doi.org/10.1016/j.foreco.2012.10.040}, DOI={10.1016/j.foreco.2012.10.040}, abstractNote={Foundation species are defined as abundant species that regulate ecosystem processes of a community through a small number of strong interactions, and eastern hemlock (Tsuga canadensis) is often cited as an example foundation species. Much of the understanding of its influence on ecosystem dynamics comes from investigations into the impact of hemlock mortality following invasion by an invasive pest, hemlock woolly adelgid (Adelges tsugae). While this information is invaluable, uncertainty remains about how much of these changes are due to disturbance, and are thus temporary, and how much is attributed to the role of hemlock, which are more permanent. To clarify the role of hemlock in intact forests, we investigated community composition and resource availability in eight hemlock dominated riparian forests on the Unglaciated Allegheny Plateau of Ohio, USA. In transects at 10, 30 and 50 m from headwater streams, we measured all vegetation strata and physiographic context. Light availability was quantified using hemispherical photography during the growing season and the deciduous leaf-off period. We also measured soil chemistry and leaf litter biomass and chemistry as metrics of nutrient cycling and productivity, and determined the relative decomposition rate using cellulose paper. Comparisons across transects indicated a high degree of similarity in community composition and function due to the direct and indirect effects of hemlock dominance. Species richness was low, with slight increases moving upslope from the streams. Productivity (leaf litter biomass), light availability (canopy openness) in the growing season and deciduous leaf-off period, and nutrient cycling (decomposition and leaf litter chemistry) was also similar across transects. Non-metric multidimensional scaling analyses indicated differences in species composition 10 m from streams compared to 30 and 50 m away from the streams. Structural equation modeling (SEM) indicated hemlock dominance has a strong negative influence on vegetation species richness, as well as light availability and productivity. This indicates that as a foundation species, hemlock exerts a stronger biotic control than dampens the abiotic influence of environmental differences, overwhelming subtle but predictable patterns in species composition. Whether other foundation species, particularly conifers, structure ecosystems through similar mechanisms merits further investigation.}, journal={Forest Ecology and Management}, publisher={Elsevier BV}, author={Martin, Katherine L. and Goebel, P. Charles}, year={2013}, month={Feb}, pages={143–152} }
 @article{martin_goebel_2012, title={Decline in riparian Tsuga canadensis forests of the central Appalachians across an Adelges tsugae invasion chronosequence}, volume={139}, ISSN={1095-5674}, url={http://dx.doi.org/10.3159/torrey-d-12-00012.1}, DOI={10.3159/torrey-d-12-00012.1}, abstractNote={Abstract Forests of eastern North American are losing Tsuga candensis (eastern hemlock) ecosystems throughout an expanding portion of its range due to the invasive pest insect Adelges tsugae (hemlock woolly adelgid: HWA). Tsuga canadensis represents a small portion of the landscape, particularly in the central and southern Appalachians where it is largely restricted to cove and riparian areas; however, it is a foundation species that defines a unique forest ecosystem. Consequently, loss of T. canadensis will result in a re-organization of ecosystem structure and function as alternate communities develop. A greater understanding this transition will advance ecological theory, but is also directly applicable to management and restoration planning. While county-level patterns of detection are readily available, less is known about the process of decline and compositional shifts. We identified riparian T. canadensis forests along thirty headwater streams across West Virginia and Virginia, representing an invasion chrononosequence of nine to thirty-two years. Sites encompassed a range in elevation, slope, and aspect, intended to identify patterns of T. canadensis dominance and decline. At each site, we sampled the overstory and sapling vegetation and recorded the crown health of each T. canadensis in transects at 10, 30, and 50 meters from the bank-full stream channel. Although in severe decline, T. canadensis continued to dominate both the overstory and sapling layers across riparian-upland transects across the central Appalachians. Structural equation modeling (SEM) indicated decline was moderated by higher elevations and landscape positions that received less incident radiation due to aspect and slope, but duration of Adelges tsugae invasion was the most influential factor in the decline of crown health for the overstory. SEM also identified decline in the overstory as the most influential factor in the decline of the sapling layer. Future forest function depends on composition, which will likely vary depending on the presence of Rhododendron maximum, an aggressive native shrub. Most importantly, functional processes that respond rapidly to T. canadensis decline are likely to experience continuing fluctuation as the composition shifts more gradually.}, number={4}, journal={The Journal of the Torrey Botanical Society}, publisher={Torrey Botanical Society}, author={Martin, Katherine L. and Goebel, P. Charles}, year={2012}, month={Oct}, pages={367–378} }
 @article{martin_hix_goebel_2011, title={Coupling of vegetation layers and environmental influences in a mature, second-growth Central Hardwood forest landscape}, volume={261}, ISSN={0378-1127}, url={http://dx.doi.org/10.1016/j.foreco.2010.12.001}, DOI={10.1016/j.foreco.2010.12.001}, abstractNote={Forest communities across the landscape of the Central Hardwood Forest Region are experiencing a transition from dominance by oak (Quercus) and hickory (Carya) to maple (Acer) driven largely by a prolonged period of fire suppression. In many cases, this shift in community composition, structure, and function is considered undesirable as oak–hickory forests are valued for timber, wildlife habitat, and natural heritage. Considerable management and restoration efforts target the restoration of oak–hickory forest communities, yet treatments have yielded varying degrees of success. In some cases, difficulties in meeting targets may be due to ecological thresholds created by complex vegetation–environment interactions that maintain the maple-dominated community state. We examined direct and indirect interactions among vegetation layers and environmental gradients for the mature, second-growth forest communities of the Ironton Unit of the Wayne National Forest (WNF) in southeastern Ohio. Using a stratified random approach, we identified 72 study communities with trees at least 70 years old and without evidence of recent disturbance. Within these communities, we sampled all overstory vegetation on two–four 500 m2 plots and recorded saplings and ground-flora species in nested sub-plots. At each plot, we also collected soil samples for physical and chemical analyses and recorded physiographic variables. Our first objective was to describe the Ironton forest landscape, where communities were likely transitioning from oak to maple. To identify such patterns, we used ordination analyses that relate species occurrence to implied environmental gradients. Our second objective was to use the relationships to develop a structural equation model (SEM) to quantify the strength of pathways among the canopy, sapling, and ground-flora vegetation layers and environmental factors (e.g., soil chemistry and physiographic position). Our results indicate that the forest landscape of the Ironton Unit of the WNF is at a transition point with communities dominated by either oak or maple, and a sapling layer dominated by maple. Maple may be most likely to replace oak and hickory in the canopies of communities at mid- and lower-slope positions with intermediate soil moisture. This transition will likely have cascading effects throughout the sapling and ground-flora layers, which SEM demonstrates are directly influenced by the canopy. We believe the simultaneous consideration of direct and indirect interactions shaping vegetation structure and composition using techniques such as SEM will advance understanding of the current transition from an oak–hickory to a maple-dominated forest landscape. This information will contribute to the continued improvement of appropriate forest management and ecosystem restoration techniques for the Central Hardwood Forest Region, including those designed to shift the dominance of forest communities from maple to oak.}, number={3}, journal={Forest Ecology and Management}, publisher={Elsevier BV}, author={Martin, Katherine L. and Hix, David M. and Goebel, P. Charles}, year={2011}, month={Feb}, pages={720–729} }
 @inproceedings{martin_goebel_2011, place={Lexington, KY}, title={Preparing for hemlock woolly adelgid in Ohio: communities associated with hemlock-dominated ravines of Ohio’s Unglaciated Allegheny Plateau}, number={NRS-P-78}, booktitle={Proceedings of the 17th Central Hardwood Forest Conference}, publisher={USDA Forest Service General Technical Report}, author={Martin, K.L. and Goebel, P.C.}, year={2011}, pages={436–446} }
 @inproceedings{martin_goebel_2010, place={Bragança, Portugal}, title={Impacts of hemlock decline on successional pathways and ecosystem function at multiple spatial scales in forests of the central Appalachians, USA}, booktitle={Forest Landscapes and Global Change - New Frontiers in Management, Conservation and Restoration: Proceedings of the IUFRO Landscape Ecology Working Group International Conference}, publisher={Instituto Politécnico de Bragança}, author={Martin, K.L. and Goebel, P.C.}, editor={Azevedo, J.C. and Feliciano, M. and Castro, J. and Pinto, M.A.Editors}, year={2010}, pages={147–152} }
 @article{martin_kirkman_2009, title={Management of ecological thresholds to re-establish disturbance-maintained herbaceous wetlands of the south-eastern USA}, volume={46}, ISSN={0021-8901 1365-2664}, url={http://dx.doi.org/10.1111/j.1365-2664.2009.01659.x}, DOI={10.1111/j.1365-2664.2009.01659.x}, abstractNote={Summary1. The restoration of disturbance-maintained ecosystems may require management to overcomeecological thresholds and re-establish feedbacks that perpetuate an alternative community. Weuse hardwood-dominated depression wetlands (locally known as oak domes) embedded in thefire-maintained longleaf pine–wiregrass Pinus palustris–Aristida stricta ecosystem as an examplewhere concepts developed from alternative state theory are applied to practical restoration.2. As extantcommunitieswerenotavailableasreferencesites,webasedourrestorationobjectiveson knowledge of vegetation dynamics, land-use history and historical data. We quantified a hard-woodencroachmentpatternbeginningwiththeestablishmentofcentralnucleiduringfire-freeperi-ods. Expansion of this core of hardwoods is positively reinforced by the accumulation of fuels thatimpedethespreadoffire.3. In order to examine the feasibility of re-establishing herbaceous communities, we selected 10depressionwetlandsin2000andrandomlyassignedahardwoodremovaltreatmenttohalfofthem.During the transition period of fine fuel accumulation, we adapted the management regime asnec-essary for control of hardwood re-sprouts and to promote the development of a fire-maintainedcommunity.4. After 5 years, hardwood removal communities had shifted toward herbaceous dominance,characterized by multi-layered, species-rich, native, wetland-specific ground flora. The rapidrecoveryofherbaceousspecieswasprobablypossiblebecauseofinitialseedlingrecruitmentfrom apersistent wetland soil seed bank. This immediate recruitment of herbaceous vegetation producedfinefuels,allowingforthereintroductionoffrequentprescribedfireand, thus,there-establishmentoftheherbaceouscommunity-firefeedbackmechanismnecessarytomaintainthecommunitystate.5. Synthesis and applications. Our findings confirm that it is possible to re-establish a rare alterna-tive community state in a fire-maintained ecosystem. Establishment of a desired transition trajec-tory required decoupling ecological feedbacks that inhibit reintroduction of fire while facilitatingpositive feedbacks to promote fire. Our approach incorporating ecological thresholds and bioticlegacies, such as a persistent seed bank, can serve as a model to inform restoration strategies forotherdisturbance-maintainedecosystems.Key-words: adaptive management, alternative community state, coastal plain, depressionwetland, ecological threshold, fire, hardwood removal, longleaf pine ecosystem, restoration,seed bank}, number={4}, journal={Journal of Applied Ecology}, publisher={Wiley}, author={Martin, Katherine L. and Kirkman, L. Katherine}, year={2009}, month={Aug}, pages={906–914} }