Geology topics

L. Arriana Brand

Publications and source records attributed to L. Arriana Brand.

4 recordsLinked to original sources

USGS2016

Desert tortoise annotated bibliography, 1991-2015

Introduction Agassiz’s desert tortoise, Gopherus agassizii , was considered a single species for 150 years after its discovery by James Cooper (1861), with a geographic range extending from southeastern California, southern Nevada, and southwestern Utah southward into northern Sinaloa, Mexico (Murphy and others, 2011). What was once G. agassizii is now recognized as a complex composed of three sister species, G. agassizii , G. morafkai , and G. evgoodei (Murphy and others, 2011; Edwards and others, 2016) (fig. 1). The geographic range of Agassiz’s Desert Tortoise ( G. agassizii ) is now limited to north and west of the Colorado River (Murphy and others, 2011), with the exception of a small population in northwestern Arizona (Edwards and others, 2015). This annotated bibliography is based on peer-reviewed journal articles published between January 1991 and December 2015 on Agassiz’s Desert Tortoise, with the geographic range as defined by Murphy and others (2011). Studies pertaining to other species of Gopherus (e.g., G. morafkai ), were included only when associated with G. agassizii . In addition to articles pertaining directly to desert tortoises, we compiled articles concerning threats to desert tortoises and the habitats they occupy. Similarly, we only included studies that encompass other habitat types when they were directly compared with habitats of G. agassizii . Agassiz’s Desert Tortoise (hereinafter called desert tortoise) is a state- and federally-listed threatened species (U.S. Fish and Wildlife Service, 1990; California Department of Fish and Game, 2015). The first population federally listed as threatened occurred on the Beaver Dam Slope, Utah (U.S. Fish and Wildlife Service, 1980). In 1990, the entire geographic range north and west of the Colorado River was federally listed as threatened (U.S. Fish and Wildlife Service, 1990), with the exception being a small population in northwestern Arizona. The purpose of this annotated bibliography is to support recovery efforts for the species, because populations have continued to decline in spite of designation of critical habitat and publication of a recovery plan (U.S. Fish and Wildlife Service, 1994). For example, between 2005 and 2014, populations in critical habitats declined about 50% (U.S. Fish and Wildlife Service, 2015).

Open-File Report↗

USGS2014

Effects of wetland management on carrying capacity of diving ducks and shorebirds in a coastal estuary

With global loss of natural wetlands, managed wetlands increasingly support energy requirements for wintering shorebirds and waterfowl. Despite numerous studies of avian bioenergetics in freshwater systems, less is known of the energetic capacity of estuarine systems. In San Francisco Bay, managed saline ponds converted from former commercial salt evaporation ponds form part of the largest wetland restoration project on the Pacific coast of North America. A daily-ration model was applied to assess carrying capacity for diving ducks and shorebirds during four winter seasons (2007–2010) in seasonal and circulation ponds, each in two salinity classes. Diving ducks comprised an estimated 35,450 ± 1,559 ( ± SE) in average years and 45,458 ± 1,653 in peak years with > 95% in circulation ponds. Shorebirds comprised 64,253 ± 14,838 ( ± SE) in average years and 108,171 ± 4,854 in peak years with > 64% in seasonal ponds. Macroinvertebrate energy density was highest in mesohaline (5–30 ppt) circulation ponds and lowest in seasonal ponds for both guilds. Energy requirements for diving ducks in mesohaline followed by low-hyperhaline (30–80 ppt) circulation ponds were mostly met by available prey energy. Available energy for shorebirds was substantially less than they required in seasonal ponds but exceeded their needs in mesohaline circulation ponds. Mesohaline circulation ponds supported 9,443 ± 1,649 ( ± SE) shorebird use-days·ha -1 of accessible habitat and 2,297 ± 402 diving duck use-days·ha -1 of accessible habitat, twice the capacity of low-hyperhaline circulation ponds and greater than five times that of seasonal ponds for both guilds. Our results indicated that reducing salinity to mesohaline levels and altering water depth to increase accessibility substantially increased energy available for these species in estuarine managed ponds.

California↗

USGS2012

Trajectory of early tidal marsh restoration: elevation, sedimentation and colonization of breached salt ponds in the northern San Francisco Bay

Tidal marsh restoration projects that cover large areas are critical for maintaining target species, yet few large sites have been studied and their restoration trajectories remain uncertain. A tidal marsh restoration project in the northern San Francisco Bay consisting of three breached salt ponds (≥300 ha each; 1175 ha total) is one of the largest on the west coast of North America. These diked sites were subsided and required extensive sedimentation for vegetation colonization, yet it was unclear whether they would accrete sediment and vegetate within a reasonable timeframe. We conducted bathymetric surveys to map substrate elevations using digital elevation models and surveyed colonizing Pacific cordgrass ( Spartina foliosa ). The average elevation of Pond 3 was 0.96 ± 0.19 m (mean ± SD; meters NAVD88) in 2005. In 2008–2009, average pond elevations were 1.05 ± 0.25 m in Pond 3, 0.81 ± 0.26 m in Pond 4, and 0.84 ± 0.24 m in Pond 5 (means ± SD; meters NAVD88). The largest site (Pond 3; 508 ha) accreted 9.5 ± 0.2 cm (mean ± SD) over 4 years, but accretion varied spatially and ranged from sediment loss in borrow ditches and adjacent to an unplanned, early breach to sediment gains up to 33 cm in more sheltered regions. The mean elevation of colonizing S. foliosa varied by pond (F = 71.20, df = 84, P < 0.0001) and was significantly lower in Ponds 4 and 5 compared with Pond 3 which corresponded with greater tidal muting in those ponds. We estimated 16% of Pond 3, 13% of Pond 4, and 24% of Pond 5 were greater than or equal to the median elevation of S. foliosa . Our results suggest that sedimentation to elevations that enable vegetation colonization is feasible in large sites with sufficient sediment loads although may occur more slowly compared with smaller sites.

California↗

USGS2011

Seasonal fecundity and source-sink status of shrub-nesting birds in a southwestern riparian corridor

Saltcedar ( Tamarix spp.) has increasingly dominated riparian floodplains relative to native forests in the southwestern U.S., but little is known about its impacts on avian productivity or population status. We monitored 86 Arizona Bell's Vireo ( Vireo bellii arizonae ), 147 Abert's Towhee ( Melozone aberti ), and 154 Yellow-breasted Chat ( Icteria virens ) nests to assess reproductive parameters in cottonwood-willow ( Populus-Salix ), saltcedar, and mesquite ( Prosopis spp.) stands along the San Pedro River, Arizona during 1999–2001. We also assessed source-sink status for each species in each vegetation type using field data combined with data from the literature. There were no significant differences in reproductive parameters between vegetation types for Abert's Towhee or Yellow-breasted Chat, although seasonal fecundity was quite low across vegetation types for the latter (0.75 ± 0.14; mean ± SE). Bell's Vireo had extremely low seasonal fecundity in saltcedar (0.10 ± 0.09) and significantly fewer fledglings per nest in saltcedar (0.09 ± 0.09) compared with cottonwood (1.07 ± 0.32). Point estimates of λ were substantially <1 for all three focal species in all habitats indicating the entire study area may be performing as a sink; 90% CI of included 1 only for Abert's Towhee across vegetation types and Bell's Vireo in cottonwood vegetation. These results are surprising given the San Pedro is considered to be one of the best remaining occurrences of lowland native riparian vegetation in the southwestern United States.

Arizona↗