Liz Dent's scientific contributions

Publications (14)

Article
Transport of fine-grained sediment from unpaved forest roads into streams is a concern due to the potential negative effects of additional suspended sediment on aquatic ecosystems. Here, we compared turbidity and suspended sediment concentration (SSC) dynamics in five non-fish bearing coastal Oregon streams above and below road crossings, during th...
Article
One objective of the Oregon State Forest riparian management strategies is to provide a long-term supply of wood to streams. We explored this objective as a case study by comparing the predicted wood loads from a riparian forest managed in accordance with Northwest Oregon State Forest Management Plan to an unmanaged riparian forest. We obtained rip...
Article
A replicated before–after-control-impact study was used to test effectiveness of Oregon’s (USA) riparian protection measures at minimizing increases in summer stream temperature associated with timber harvest. Sites were located on private and state forest land. Practices on private forests require riparian management areas around fish-bearing stre...
Conference Paper
We examined the efficacy of timber harvest regulations at protecting Oregon Coast Range stream temperatures at 33 sites over seven years. Although Pacific Northwest states began enacting riparian timber harvest regulations decades ago to protect salmonid habitat quality and human health, we lack information regarding regulatory sufficiency. Charact...
Article
Oregon's forested coastal watersheds support important cold-water fisheries of salmon and steelhead (Oncorhynchus spp.) as well as forestry-dependent local economies. Riparian timber harvest restrictions in Oregon and elsewhere are designed to protect stream habitat characteristics while enabling upland timber harvest. We present an assessment of r...
Conference Paper
Background/Question/Methods Stream temperature affects aquatic system productivity, community composition, and species’ developmental rates and fecundity. Anthropogenic elevation of stream temperature is a common water quality concern for Pacific Northwest states due to its effects on salmonid development and survival. Riparian timber harvest and...
Article
Full-text available
  Cool summertime stream temperature is an important component of high quality aquatic habitat in Oregon coastal streams. Within the Oregon Coast Range, small headwater streams make up a majority of the stream network; yet, little information is available on temperature patterns and the longitudinal variability for these streams. In this paper we d...
Article
Research shows that low-volume roads, including commonly studied forest roads, can have many effects on water quality and aquatic resources. The temporal and spatial relationships of these environmental effects are complex. Water quality sampling is costly, and results are difficult to link to specific road problems. Research results from other roa...
Article
Full-text available
The major forest nonpoint source control programs in the West are largely regulatory, either under forest practices acts (California, Idaho, New Mexico, Nevada, Oregon, and Washington) or a streamside management act (Montana). These programs and the specific rules they enforce con-tinue to undergo intensive scrutiny. Still, the questions are the sa...
Article
Acknowledgments Researchers and managers from British Columbia, Washington, Oregon, California, Idaho, Colorado, and Georgia attended the workshop. These participants contributed valuable input to the Headwaters Research Cooperative that will help guide the cooperative’s research priorities. The Oregon Headwaters Research Workshop and this summary...

Citations

... Specifically, forest roads have geomorphologically active surfaces, which suffer serious erosion during and following heavy rainfall events (Solgi et al., 2021). These soil losses complicate forest management and pollute downstream surface waters, degrading aquatic habitats by altering the chemical, biological, and physical processes of streams (Al-Chokhachy et al., 2016;Arismendi et al., 2017;Mann et al., 2019;Zhao et al., 2022a). Because of these vast ecological repercussions, forest management must develop and incorporate methods to mitigate road erosion to prevent further degradation. ...
... Legacies of prior disturbances modify habitat availability and therefore species responses to current forest management. Such legacies have been observed for the amount of wood in streams, which is influenced by prior harvest and fire history (McDade et al. 1990, Meleason et al. 2003, Meleason et al. 2013, Czarnomski et al. 2008. Legacies are also evident in the types of stream substrates, influenced by debris flows and amount of down wood in the streams. ...
... In Oregon coastal streams, mean stream temperature tends to increase with distance downstream as a result of exposure of the stream surface to solar radiation and warmer air temperatures (Sullivan et al. 1990, Dent et al. 2008, Groom et al. 2011. However, other work has shown that for some streams, longitudinal trends in temperature are more complex (Fullerton et al. 2015(Fullerton et al. , 2018. ...
... Stream temperatures in both basins gradually returned to pre-harvest levels after 15 years; important factors influencing the temperature increases were removal of riparian vegetation, and conduction between stream water and nearby soils or substrates (Johnson and Jones, 2000). Also in Oregon, Groom et al. (2011) indicated that retaining buffers reduced temperature increases in streams following harvesting. Similarly, Gomi et al. (2006) found in British Columbia that daily maximum temperature in summer increased by up to 2 • C to 8 • C after harvesting in streams where no riparian buffer was retained. ...
... Borovansky et al. (editors, 2002) recommended the development of road inventories and assessments at multiple scales and cited several conservation opportunities that could be identified during the inventory process. As well, Reed et al. (1996), Gucinski et al. (editors, 2001), and Mills (2007) emphasized the need for current, accurate road inventories that include information useful during environmental effects analyses. For example, inventory specialists can gather information about drainage, erosion, wetland and stream-crossing problems, water diversion potential, and road maintenance and repair needs. ...
... Knowledge about the effectiveness of current forestry practices in protecting downstream resources during chemical applications is limited for Oregon Coast Range watersheds. For example, little information exists to document the effects of no buffer protections under the OFPA for non-fish bearing streams (at the time of sampling), although they comprise up to 70% of the river miles in some watersheds [12,23,24]. Investigations in the neighboring Washington state have led to restrictions in chemical types and buffers on intermittent streams to improve protection of downstream resources [25]. ...
... CDF and BOF chose to place more initial emphasis on hillslope monitoring for the Long-Term Monitoring Program because it can provide a more immediate, cost effective and direct feedback loop to resource managers on impacts from current timber operations when compared to instream monitoring (particularly channel monitoring which involves coarse sediment parameters) (Reid and Furniss 1999). As stated in Robben and Dent (2002), it is usually easier to identify a sediment source and quantify the volume of sediment it produced, when compared to measuring sediment in the watercourse and tracing it to the source. ...
... Changes in forest land uses can affect streamflow, sediment, organic matter, and thermal regimes (Wohl et al., 2015;Steel et al., 2017;Wohl et al., 2019;Segura et al., 2020), potentially disrupt aquatic and riparian ecosystems (Anderson et al., 1976;Nisbet, 2001), and ultimately degrade water quality of managed watersheds (Binkley and Brown, 1993). Accordingly, management guidelines are developed with the intent to reduce or mitigate potential impacts of land use on aquatic and riparian habitat and downstream water quality (e.g., Aust and Blinn, 2004;Ice et al., 2004;Shepard, 2006;Croke and Hairsine, 2006;Anderson and Lockaby, 2011;Cristan et al., 2016). ...
... In Oregon coastal streams, mean stream temperature tends to increase with distance downstream as a result of exposure of the stream surface to solar radiation and warmer air temperatures (Sullivan et al. 1990, Dent et al. 2008, Groom et al. 2011. However, other work has shown that for some streams, longitudinal trends in temperature are more complex (Fullerton et al. 2015(Fullerton et al. , 2018. ...