Analyzing the Impacts of Off-Road Vehicle (ORV) Trails on Watershed Processes in Wrangell-St. Elias National Park and Preserve,Alaska |
| |
Authors: | Email author" target="_blank">Christopher?D?ArpEmail author Trey?Simmons |
| |
Institution: | (1) Alaska Science Center, U.S. Geological Survey, Anchorage, AK 99508, USA;(2) Present address: Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA;(3) Central Alaska Inventory and Monitoring Network, National Park Service, Fairbanks, AK 99709, USA |
| |
Abstract: | Trails created by off-road vehicles (ORV) in boreal lowlands are known to cause local impacts, such as denuded vegetation,
soil erosion, and permafrost thaw, but impacts on stream and watershed processes are less certain. In Wrangell-St. Elias National
Park and Preserve (WRST), Alaska, ORV trails have caused local resource damage in intermountain lowlands with permafrost soils
and abundant wetlands and there is a need to know whether these impacts are more extensive. Comparison of aerial photography
from 1957, 1981, and 2004 coupled with ground surveys in 2009 reveal an increase in trail length and number and show an upslope
expansion of a trail system around points of stream channel initiation. We hypothesized that these impacts could also cause
premature initiation and headward expansion of channels because of lowered soil resistance and greater runoff accumulation
as trails migrate upslope. Soil monitoring showed earlier and deeper thaw of the active layer in and adjacent to trails compared
to reference sites. Several rainfall-runoff events during the summer of 2009 showed increased and sustained flow accumulation
below trail crossings and channel shear forces sufficient to cause headward erosion of silt and peat soils. These observations
of trail evolution relative to stream and wetland crossings together with process studies suggest that ORV trails are altering
watershed processes. These changes in watershed processes appear to result in increasing drainage density and may also alter
downstream flow regimes, water quality, and aquatic habitat. Addressing local land-use disturbances in boreal and arctic parklands
with permafrost soils, such as WRST, where responses to climate change may be causing concurrent shifts in watershed processes,
represents an important challenge facing resource managers. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|