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Remote Detection of Disturbance from Motorized Vehicle Use in Appalachian Wetlands
Abstract and Figures
Wetland disturbance from motorized vehicle use is a growing concern across the Appalachian coalfields of southwestern Virginia and portions of adjacent states, particularly as both extractive industries and outdoor recreation development expand in regional communities. However, few attempts have been made in this region or elsewhere to adapt approaches that can assist researchers and land managers in remotely identifying and monitoring wetland habitats disturbed by motorized vehicle use. A comparative analysis of wetlands impacted and unimpacted by off-road vehicle activity at a public recreation area in Tazewell County, Virginia was conducted to determine if and how a common, satellite-derived index of vegetation health, normalized difference vegetation index (NDVI), can remotely detect wetland disturbance. NDVI values were consistently lower in wetlands impacted by several years of off-road vehicle use when compared to adjacent, unimpacted sites, with statistically-significant NDVI coldspots growing in size in impacted wetlands across the same time period. While considerations exist related to the resolution of data sources and the identification of specific modes of disturbance, NDVI and associated spatial analysis tools may provide a simple and cost-effective way for researchers and land managers to remotely monitor rates of wetland disturbance across mountainous portions of the eastern United States.
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... This is particularly the case for off-road vehicle (ORV) trail development, with many postmined landscapes being targeted for ORV trail systems (Sharp et al., 2020) and more than 800 km of state-managed ORV trails developed in the Virginia coalfields since 2012 (Institute for Service Research, 2017). A popular feature of ORV trail development is the conversion of pre-existing artificial pools and natural wetland habitat into play areas for vehicles, in which wetland areas are opened to "mudding," or in-pool recreational vehicle use (Meyer, 2002;Smith, 2021). One potential impact from these activities is the functional loss of artificial wetlands as amphibian breeding habitat, since extensive in-pool vehicle use may crush amphibian eggs and larvae or degrade water quality below levels supporting amphibian development. ...
... Recreational use from motorized vehicles within wetlands can be an additional source of these impacts. For example, wetlands in Tazewell County, Virginia opened to ORV use showed a significant decline in wetland condition over a six-year period, with indicators of emergent vegetation loss and soil rutting increasing relative to nearby unimpacted controls (Smith, 2021). Amphibian eggs deposited in similar habitats may also be susceptible to direct or indirect impacts from the same forms of disturbance, as was confirmed in this study. ...
Pool-breeding amphibians are reliant upon small, isolated, and fishless wetlands as sites for oviposition and larval development. These pools are often susceptible to impacts from anthropogenic disturbances, with off-road vehicle (ORV) trail development becoming an increasingly common form of wetland disturbance in the southwest Virginia coalfields. I performed a before-after control-impact (BACI) comparison of egg mass loss at 15 pools impacted and unimpacted by ORV trail development at a recently-opened public ORV trail system in Russell County, Virginia during the spring of 2024. Pools impacted by ORV use showed a mean 83% egg mass loss rate over just one week of trail use relative to no egg loss in unimpacted pools, with distinct mechanisms associated with ORV use (physical crushing, wheel-thrown eggs, and egg mass relocation) acting in concert to drive egg mass loss. My results provide some of the first empirical data documenting mechanisms of egg mass loss and embryonic mortality in pool-breeding amphibians from ORV disturbance and support several best management practices that land managers in Virginia and elsewhere can use to minimize impacts to resident amphibian populations on public and private lands managed for recreation.
... terrain characteristics, with wetland formation restricted primarily to narrow floodplain habitats along larger waterways and small, midslope seepage areas where groundwater is discharged on the ground surface (Thompson et al. 2007;Fleming and Patterson 2017). However, this region also contains a small number of rare, geographically-isolated wetlands perched in high-elevation (>900 m above sea level, asl) areas, including isolated wetlands formed in small ridge-top depressions and open-canopy wetlands at locations where relatively flat terrain occurs along the headwater reaches of firstorder, high-elevation streams (Risk 1998;Jones 2005;Smith 2021). ...
... Past work has also highlighted anthropogenic threats to high-elevation wetlands of the type surveyed through this study, including damage from off-road recreation activities and residential development, as well as from timber harvesting, surface mining and gas drilling, and other resource extraction activities (Murdock 1994;Pearson 1994;Bedford and Godwin 2003;Smith 2021). The use of this study's focal wetlands as breeding habitats by a number of amphibian species -as well as the apparent presence of disjunct populations of lowlandassociated amphibians -further underscores the potential susceptibility of such wetlands to various forms of anthropogenic disturbance. ...
High-elevation wetlands of the Cumberland Mountains physiographic province hold high conservation priority due to their relative rarity, with little knowledge in the literature related to amphibians' use of these high-elevation habitats. Therefore, forest and wildlife managers have few data to use when designing management guidelines for these habitats. We sampled five high-elevation wetlands across Pine and Cumberland mountains along the Virginia-Kentucky border, United States of America to address gaps in knowledge about these habitats and their use by amphibians. We inventoried amphibian diversity at five wetlands using visual encounter and auditory surveys. We used standardized, area-constrained visual encounter surveys that consisted of searches of all available cover objects within a 10 m buffer of the wetland margin to inventory amphibian taxa at each site. We also used automated digital recorders to record auditory call data from anuran (frogs and toads) taxa. We encountered 18 total amphibian species (eight anuran and ten salamander species), recording numerous occurrences of some species, such as Mud Salamanders (Pseudotriton montanus Baird), that have previously been assumed to be absent from high-elevation wetlands in the Appalachian region. Statistical analyses further indicated high disparity in amphibian biodiversity between sites. Our results indicate that these wetlands should be of high conservation concern and should be given priority in regional habitat management efforts.
Global trends in wetland degradation and loss have created an urgency to monitor wetland extent, as well as track the distribution and causes of wetland loss. Satellite imagery can be used to monitor wetlands over time, but few efforts have attempted to distinguish anthropogenic wetland loss from climate-driven variability in wetland extent. We present an approach to concurrently track land cover disturbance and inundation extent across the Mid-Atlantic region, United States, using the Landsat archive in Google Earth Engine. Disturbance was identified as a change in greenness, using a harmonic linear regression approach, or as a change in growing season brightness. Inundation extent was mapped using a modified version of the U.S. Geological Survey's Dynamic Surface Water Extent (DSWE) algorithm. Annual (2015-2018) disturbance averaged 0.32% (1095 km 2 year-1) of the study area per year and was most common in forested areas. While inundation extent showed substantial interannual variability, the co-occurrence of disturbance and declines in inundation extent represented a minority of both change types, totaling 109 km 2 over the four-year period, and 186 km 2 , using the National Wetland Inventory dataset in place of the Landsat-derived inundation extent. When the annual products were evaluated with permitted wetland and stream fill points, 95% of the fill points were detected, with most found by the disturbance product (89%) and fewer found by the inundation decline product (25%). The results suggest that mapping inundation alone is unlikely to be adequate to find and track anthropogenic wetland loss. Alternatively, remotely tracking both disturbance and inundation can potentially focus efforts to protect, manage, and restore wetlands.
The unprecedented global biodiversity loss has massive implications for the capacity of ecosystems to maintain functions critical to human well‐being, urgently calling for rapid, scalable, and reproducible strategies for biodiversity monitoring, particularly in threatened ecosystems with difficult field access such as wetlands. Remote sensing indicators of spectral variability and greenness may predict the diversity of plant communities based on their optical diversity; however, most evidence is based on narrowband spectral data or terrestrial ecosystems. We investigate how spectral greenness and heterogeneity from publicly available broadband multi‐spectral Landsat satellite imagery explain variation in vegetation diversity across different wetland types, ecoregions, and disturbance levels using 1,138 sites surveyed by U.S. EPA's National Wetland Condition Assessment. We found positive correlations of plant species richness and diversity with indicators of annual maximum spectral greenness and its spatial heterogeneity, explaining up to 43% variation within the global sample, 48% within wetland types or ecoregions, and up to 61% with abiotic covariates. The combined effect of spectral greenness and heterogeneity was stronger than the best‐performing model using climatic, topographic, and edaphic factors alone. When compared among major U.S. watersheds and individual states, the fit of diversity‐greenness models increased when more wetland types were included within the corresponding region's boundaries, up to 61% at the watershed and 77% at the state level, respectively, for diversity models and up to 73% and 80%, respectively, for richness models. Model outliers were characterized by a significantly greater diversity of nonnative species (P < 0.0001), suggesting that changes in model performance and greenness distributions could be used as indicators of shifts in plant community composition, particularly in tidal wetlands making the majority of outliers with significantly lower than predicted diversity. This study represents a first‐time national‐scale effort to use publicly available remote sensing, climatic, and topographic data to predict plant diversity in wetlands, which tend to be understudied compared to terrestrial ecosystems despite being among the most stressed ecosystems on Earth. Our study suggests that multi‐temporal broadband satellite imagery could provide a low‐cost assessment of regional and national wetland biodiversity for prioritization of conservation efforts and early detection of biodiversity loss.
Surface coal mining can permanently alter the rugged topography of Appalachia, which plays an important role in creating and maintaining the structure, composition, and diversity of this North American region's ecological communities. We used remote‐sensing datasets to characterize the past and future topographic impacts of surface coal mining on the mixed‐mesophytic forests of eastern Kentucky. To provide context, we examined the consequences of widespread topographic rearrangement for an imperiled ridgetop‐associated predator, the timber rattlesnake (Crotalus horridus). We found that surface mining disproportionately impacts ridgetop habitats, causing large reductions in suitable habitat for C horridus, and most likely other ridgetop‐dependent biota as well. Land permitted for surface mining is also concentrated in high topographic positions, and patterns of habitat loss are therefore likely to remain concentrated within these ecosystems. These permanent topographic shifts complicate restoration of pre‐existing microhabitats, create homogenized landscapes, threaten long‐term ecosystem health, and reduce the diversity of ecological communities.
The analysis of wildfire impacts at the scale of less than a square kilometer can reveal important patterns of vegetation recovery and regrowth in freshwater Arctic and boreal regions. For this study, NASA Landsat burned area products since the year 2000, and a near 20-year record of vegetation green cover from the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite sensor were combined to reconstruct the recovery rates and seasonal profiles of burned wetland ecosystems in Alaska. Region-wide breakpoint analysis results showed that significant structural change could be detected in the 250-m normalized difference vegetation index (NDVI) time series for the vast majority of wetland locations in the major Yukon river drainages of interior Alaska that had burned at high severity since the year 2001. Additional comparisons showed that wetland cover locations across Alaska that have burned at high severity subsequently recovered their green cover seasonal profiles to relatively stable pre-fire levels in less than 10 years. Negative changes in the MODIS NDVI, namely lower greenness in 2017 than pre-fire and incomplete greenness recovery, were more commonly detected in burned wetland areas after 2013. In the years prior to 2013, the NDVI change tended to be positive (higher greenness in 2017 than pre-fire) at burned wetland elevations lower than 400 m, whereas burned wetland locations at higher elevation showed relatively few positive greenness recovery changes by 2017.
Watershed restoration efforts seek to rejuvenate vegetation, biological diversity, and land productivity at Cienega San Bernardino, an important wetland in southeastern Arizona and northern Sonora, Mexico. Rock detention and earthen berm structures were built on the Cienega San Bernardino over the course of four decades, beginning in 1984 and continuing to the present. Previous research findings show that restoration supports and even increases vegetation health despite ongoing drought conditions in this arid watershed. However, the extent of restoration impacts is still unknown despite qualitative observations of improvement in surrounding vegetation amount and vigor. We analyzed spatial and temporal trends in vegetation greenness and soil moisture by applying the normalized difference vegetation index (NDVI) and normalized difference infrared index (NDII) to one dry summer season Landsat path/row from 1984 to 2016. The study area was divided into zones and spectral data for each zone was analyzed and compared with precipitation record using statistical measures including linear regression, Mann–Kendall test, and linear correlation. NDVI and NDII performed differently due to the presence of continued grazing and the effects of grazing on canopy cover; NDVI was better able to track changes in vegetation in areas without grazing while NDII was better at tracking changes in areas with continued grazing. Restoration impacts display higher greenness and vegetation water content levels, greater increases in greenness and water content through time, and a decoupling of vegetation greenness and water content from spring precipitation when compared to control sites in nearby tributary and upland areas. Our results confirm the potential of erosion control structures to affect areas up to 5 km downstream of restoration sites over time and to affect 1 km upstream of the sites.
This study assessed the spatial patterns of significant negative trend of forest seasonal greenness over the different forest types of India using 8-day composite MODIS NDVI (500 m) time series data (2001–2014). It was further analyzed to quantify the negative changes in the core forest areas and to identify hotspots of it over the large protected forest areas. Significant negative changes in the seasonal greenness were found to be highest over tropical moist deciduous forest (2067.35 thousand ha) followed by tropical dry deciduous (1407.73 thousand ha), tropical wet evergreen (577.43 thousand ha), tropical semi evergreen (442.58 thousand ha), subtropical broad leaved (321.13 thousand ha) and Himalayan moist temperate forest (293.80 thousand ha). Mangroves forest also showed decrease in its greenness over 15.6% of its total area. Interestingly, most of the observed negative changes of high to medium magnitude were found in the core areas of the forest types. Hotspots analysis revealed spatially coherent significant negative changes of seasonal greenness over the large protected areas i.e. Similipal wildlife sanctuary of Odisha, Rajaji national park of Uttarakhand, Achanakmar wildlife sanctuary of Chhattisgarh and Sundarban of West Bengal. The outcomes of the present study would help in the prioritization of the forest types and protected forest areas for biodiversity conservation and climate change mitigation programmes.
This community note describes a five-year academic-community partnership between a community organization and two universities in Kentucky. It also documents the potential of adventure tourism to help diversify the community's economy and contribute to the quality of life in the region. While recognizing that adventure tourism cannot make up for the loss of the area's traditional economic base, the data indicate that adventure tourism can make a positive contribution to the quality of life, environmental quality, and sustainability of the town. A major obstacle to achieving the community organization's goals to develop adventure tourism has been the failure to get buy-in from local government leaders.
Outdoor recreation entails a careful balance between environmental impact and economic impact, particularly in rural Appalachian transitional economies. Outdoor recreation annually brings millions of dollars into rural areas in Central Appalachia by utilizing the natural features of the region for recreation. However, uneven development has fomented long-standing environmental injustices as extraction industries utilize unparalleled control over the natural environment and its use. In this article, the researchers examine Kentucky off-highway vehicle (OHV) use patterns as they pertain to the environment alongside their generalized household economic expenditures per trip. Off-highway vehicle users represent a legitimate claim to public land use, and thus findings of this article reinforce the need for caution in balancing the economic impacts and environmental costs of outdoor recreation, including OHV use.
In 2004 migration and mortality for unknown reasons of the herbivorous Black necked swan (Cygnus melancorhyphus (Molina, 1782)) occurred within the Río Cruces wetland (southern Chile), a Ramsar Site and nature sanctuary. Before 2004, this wetland hosted the largest breeding population of this water bird in the Neotropic Realm. The concurrent decrease in the spatial occurrence of the aquatic plant Egeria densa Planch. 1849 - the main food source of swans - was proposed as a cause for swan migration and mortality. Additionally, post-mortem analyses carried out on swans during 2004 showed diminished body weight, high iron loads and histopathological abnormalities in their livers, suggesting iron storage disease. Various hypotheses were postulated to describe those changes; the most plausible related to variations in water quality after a pulp mill located upstream the wetland started to operate in February 2004. Those changes cascaded throughout the stands of E. densa whose remnants had high iron contents in their tissues. Here we present results of a long-term monitoring program of the wetland components, which show that swan population abundance, body weights and histological liver conditions recovered to pre-disturbance levels in 2012. The recovery of E. densa and iron content in plants throughout the wetland, also returned to pre-disturbance levels in the same 8-year time period. These results show the temporal scale over which resilience and natural restoring processes occur in wetland ecosystems of temperate regions such as southern Chile.