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Open Access Publications from the University of California

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The Road Ecology Center at the University of California, Davis integrates ecological sciences, engineering, and social sciences to study the interactions between roads and the surrounding natural and human environment, and to develop sustainable transportation solutions that are environmentally and socially friendly. The purpose of the UC Davis Road Ecology Center is to foster and develop a science of road ecology; to support university-based training and education in road ecology; develop scientifically-sound assessment tools, frameworks, and practices to be used in planning and management of sustainable transportation systems; and to share research findings and information in partnership with environmental scientists, professional organizations, governmental agencies, and public interest groups. As road use continues to increase, there is an urgent need to bring together the research findings of planners, policymakers, educators and researchers in a single archive. Awareness of the pervasiveness of road effects has grown, so that we now have an opportunity to provide information that will help us develop scientific tools to understand the underlying relationships, and to incorporate this understanding in planning today's transportation systems.

Road Ecology Center

There are 478 publications in this collection, published between 1995 and 2016.
Recent Work (478)

Major Objectives for Road Ecology to Benefit Transportation and Society

Pinpointing major objectives as a vision for transportation and society provides a cost-effective framework for numerous detailed solutions along the road network. Three major objectives, with road ecology a central player, are highlighted: (1) improve the natural environment close to the entire road network; (2) integrate roads with a sustainable emerald network across the landscape; and (3) integrate roads with near-natural water conditions across the land¬scape. These are briefly described along with examples of possible key steps ahead. In effect, this big picture or vision is a cost-effective route to achievement and benefit for transportation, the environment, and society.

Species conservation in Idaho—going beyond the ESA

Results of listing species under the Endangered Species Act (ESA) have been less than inspiring. Since enactment of the ESA, slightly over 1300 species have been listed as threatened or endangered. Only 12 of these species have recovered to the point of being delisted. Roughly 40 others have been removed from listing due either to extinction, errors in the original listing decision, or other reasons. Congress directs that 75 percent of funding for recovery of species goes to about 10 species, leaving the remaining 25 percent to be applied to all the remaining listed species. A major focus of the Endangered Species Act is on listing of species. Once a species becomes listed, time-consuming and complex consultation is often required to avoid liability under the act. That consultation process can discourage and delay implementation of actions beneficial to the species. In Idaho, efforts have been made to utilize Candidate Conservation Agreements (CCAs) and Candidate Conservation Agreements with Assurances (CCAAs) to avoid the need to list additional species and provide direct beneficial effects for species. Slickspot Pepppergrass (Lepidium papilliferum, or SSPG) is an annual or biennial white flower thought to occur only in southern Idaho. It is found in the sagebrush habitats of the Snake River Plain and possesses an unusual habitat requirement (“slick spots” of clay soils). Information on the plant’s historical range, habitat needs, and population trends had been limited and largely anecdotal. On and off, SSPG was designated as a candidate species under ESA for over a decade. Threats to the species include grazing, non-native plants, development, recreation, wildfire, fire suppression, and fire-prevention activities. A lawsuit was initiated in 2001 demanding emergency listing of SSPG under the ESA. In settlement of that that suit, the Fish and Wildlife Service (FWS) was under a court order for a decision to list SSPG as threatened or endangered by July 2003. In early 2003, the state Office of Species Conservation was made aware that FWS believed that an endangered listing was appropriate based on the information available and that significant changes in land use would result from this listing. Through negotiation by interested parties including the Office of Species Conservation, Idaho Department of Fish and Game, Idaho National Guard, Idaho Bureau of Land Management (BLM), and a consortium of ranching interests, efforts were made to avoid listing of the species through development of a CCA. In July 2003, FWS delayed their listing decision by six months in order to allow for completion of the CCA and resolution of some final issues. FWS and NOAA’s Policy for Evaluation of Conservation Efforts (or PECE policy) was applied as a guideline for the development of this CCA; this was the first application of the PECE policy in development of a CCA. Conservation measures prepared to address each threat to SSPG were included in the CCA. A FWS-facilitated scientific review panel validated conclusions reached by the SSPG partnership and found that the CCA would substantially delay risks of extinction of SSPG. In January 2004, FWS issued a determination that the proposal to list SSPG was not warranted because of the management plans developed and instituted under the CCA. This was a win-win solution for all parties to the agreement and for the species. The benefits include: 1) conservation measures to benefit the covered species are developed and put into place on both public and private lands across a large geographic area, 2) users such as grazing permittees get routine processing of renewals, assuming the terms of the CCA are being met, 3) landowners and state agencies get Section 10 incidental take coverage and assurances that additional restrictions will not be placed on their lands or operations, and 4) federal agencies get reduced consultation requirements. Since this CCA was developed, another CCA has been developed for the Southern Idaho Ground Squirrel (Spermophilus brunneus endemicus). A programmatic CCA is currently being completed for the Southern Idaho Ground Squirrel that will allow other parties to enter into the CCA and participate in the benefits by agreeing to implement the conservation measures described. A multi-species CCA for Idaho is also currently under development. More applications of this concept are possible, but they can be challenging to develop. Early establishment of a baseline of the “best available scientific information” for a species is one of the most important early steps that can be taken to facilitate development of a CCA and/or CCAA.

What do we know about pile driving and fish?

There are growing concerns about the potential effects of in-water pile driving on aquatic organisms. These concerns arise from an increased awareness that high-intensity sounds have the potential to harm both terrestrial and aquatic vertebrates (e.g., Fletcher and Busnel 1978; Kryter 1984; Richardson et al. 1995; Popper 2003; Popper et al. 2004). The result of exposure to intense sounds may extend over a continuum running from little or no effects to the death of the ensonified organism. This paper is a brief review of what is known about the effects of pile driving on fish. It also provides some ideas about the design of future experiments that can be used to test these effects. The conclusions and recommendations presented here are explored in far more detail in a recent review on effects of pile driving on fish (Hastings and Popper 2005). In addition, a broader examination of the general effects of sound on fishes can be found in Popper (2003) and Popper et al. (2004). It is widely believed that fish close to pile-driving activities may be killed by exposure to very intense sounds. There is also some evidence that fish at some greater (but undefined) distance may survive exposure to pile-driving activities. However, experimental data are very limited. Moreover, nothing is known about non-life-threatening effects on fish of some (undefined) distance from the pile-driving operation. Such effects may include (a) non-life threatening damage to body tissues, (b) physiological effects including changes in stress hormones or hearing capabilities, or (c) changes in behavior (discussed in Popper et al. 2004). These effects could be temporary (e.g., a temporary loss of hearing that recovers over time) or of sufficient length to lower long-term survival and/or reproductive potential of individual animals or communities. There are also no data on effects of cumulative exposure to pile-driving sounds. The concerns about currently available pile-driving data arise because there is very little quantification and replication of experiments and because the investigators were not able to control the stimulus to which the fish were exposed. Thus, little is known about the stimulus actually received by fish during experiments. It therefore becomes difficult to evaluate the effects of pile driving on fish that are at different distances from the source. Moreover, there are no studies to date that included observations of the behavior of fish during exposure to pile-driving signals (but see paper by Hawkins in this volume). Because of the dearth of data on effects of pile driving on fish, it has been suggested that data from other types of experiments involving intense signals be extrapolated to pile driving. A problem, however, is that the sounds used in other studies, such as the effects of sonar (Popper et al. 2005a), seismic air guns (Pearson et al. 1992; Engås et al. 1996; Wardle et al. 2001; McCauley et al. 2003; Popper et al. 2005b), and pure tones (Enger 1981; Hastings et al. 1996) differ greatly from sounds produced during pile-driving activities. Moreover, there are also concerns about extrapolating effects between species, and particularly between species that have different life styles, sound-detection capabilities, and responses to adverse stimuli (see Hastings et al. 1996; McCauley et al. 2003; Popper et al. 2005b). Furthermore, there is some evidence to suggest that it may not always be possible to generalize the effects of high-intensity sounds between different age classes of the same species (e.g., Popper et al. 2005b). Since there are issues with the way pile-driving experiments have been done to date, it is worth considering how one might design an experiment that would provide the data needed to understand the effects of pile driving or, for that matter, any intense sound, on fish. One caveat with these suggestions, however, is that they require that fish be kept in a limited locale (e.g., a cage or tank) so that they can be observed before, during, and after the sound exposure, and that the fish can be retrieved for physiological and morphological analysis. Such requirements preclude direct observations on how fishes might behave if they were free from constraints or confinement during the exposure to pile driving, as has been done in one study on the effects of seismic air guns on fishes on a reef (Wardle et al. 2001).

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