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Ultraviolet-B (UV-B) radiation has been increasing in temperate latitudes in recent decades and is expected to continue rising for some time. Enhanced UV-B radiation can change plant chemistry, yet the effects of these changes on mammalian herbivores are unknown. To examine the influence of enhanced UV-B radiation on nutrition of a specialist and generalist hindgut fermenter, we measured nutritional and chemical constituents of three common North American range plants, big sagebrush (Artemisia tridentata), yarrow (Achillea millefolium), and bluebunch wheatgrass (Pseudoregneria spicata), and how these changes influenced in vitro dry matter digestibility and in vivo digestibility by pygmy rabbits (Brachylagus idahoensis)...
These data are associated with an article published in Global Ecology and Conservation (https://doi.org/10.1016/j.gecco.2020.e01173) that describes climate's cascading effects on disease, predation, and hatching sucess in the Yosemite toad (Anaxyrus canorus). The Yosemite toad currently is federally listed as threatened under the U.S. Endanered Species Act based upon reported population declines and vulnerability to climate and other global-change factors. The species occurs only in California’s central Sierra Nevada at medium to sub-alpine elevations. Lands throughout its range largely are protected from development, but climate and other global-change factors potentially can limit populations.
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. To assess and document the depths to the tops of individual A. canorus and Pseudacris regilla egg masses and to the sediments, we measured water depths at masses of both species. We used a meter stick to measure the depth (nearest mm) where female A. canorus deposited individual egg masses, and the distance from the water’s surface to the tops of those masses, at several breeding sites across 1996, 1998, 1999, and 2000. We did the same for egg masses of P. regilla...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. ENCLOSURES We used field enclosures to test the hypothesis that exposure to ambient UV-B caused embryo mortality in 1996 and 1998. We covered the top of each enclosure with one or two types of thin plastic sheeting. One type was transparent to the solar spectrum. The other type filtered UV-B below 314 nm (UV-B<314) but was otherwise transparent to solar radiation. Laying both types together over the top of an enclosure did not alter the transmission characteristics...
Reactive oxygen species (ROS) are involved in the oxidative damage of the cyanobacterium Anabaena sp. caused by UV-B (280?315 nm) radiation. UV-B-induced overproduction of ROS as well as the oxidative stress was detected in vivo by using the ROS-sensitive probe 2?,7?-dichlorodihydrofluorescein diacetate (DCFH-DA). Thiobarbituric acid reactive substances (TBARS) and fluorometric analysis of DNA unwinding (FADU) methods were adapted to measure lipid peroxidation and DNA strand breaks in Anabaena sp. Moderate UV-B radiation causes an increase of ROS production, enhanced lipid peroxidation and DNA strand breaks, yielding a significantly decreased survival. In contrast, the supplementation of UV-A in our work only showed...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. From 1999 to 2001, we deployed Optic StowAway Temperature loggers (Onset Computer Corporation; Bourne, Massachusetts, USA) to measure minimum daily air temperatures at various breeding sites during embryogenesis for A. canorus. These measurements enabled us to determine relations between air temperatures at individual breeding sites relative to air temperatures measured at the automated weather station in Dana Meadows (DAN) in the heart of our study area. We measured...
Reactive oxygen species (ROS) are involved the damage of living organisms under environmental stress including UV radiation. Cyanobacteria, photoautotrophic prokaryotic organisms, also suffer from increasing UV-B due to the depletion of the stratospheric ozone layer. The increased UV-B induces the production of ROS in vivo detected by using the ROS-sensitive probe 2?,7?-dichlorodihydrofluorescein diacetate (DCFH-DA). Ascorbic acid and N-acetyl- -cysteine (NAC) scavenged ROS effectively, while ?-tocopherol acetate or pyrrolidine dithiocarbamate (PDTC) did not. The presence of rose bengal and hypocrellin A increased the ROS level by photodynamic action in the visible light. The presence of the herbicide, 3-(3,4-dichlorophenyl)-1,1-dimethyl...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. We assessed the extent of annual mortality among embryos of A. canorus and Pseudacris regilla variously among breeding sites and years by measuring hatching success in as many individual egg masses as possible, given logistical constraints, at sites we surveyed annually from 1996 to 2000. We visually evaluated each individual embryo in an egg mass in situ while kneeling alongside it immediately before, at, or very soon after hatching (when individual capsules remained...
Ozone depletion has caused ultraviolet-B (UV-B) radiation to rise in temperate latitudes of both hemispheres. Enhanced UV-B radiation can affect plant nutritional chemistry, but the effects of these changes on mammalian herbivores are unknown. Therefore, we measured nutritional and chemical constituents of 18 forages and related changes to in vitro dry matter digestibility, and intake and in vivo digestibility of five of these plants by a ruminant herbivore (blue duiker, Cephalophus monticola) and a specialist (pygmy rabbit, Brachylagus idahoensis ) and generalist (eastern cottontail, Sylvilagus floridanus ) hindgut-fermenter. Forages were irradiated for three months with ambient (1X) or supplemental (1.6X) UV-B...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. To assess embryo mortality, we visually evaluated each individual embryo in an egg mass in situ while kneeling alongside it immediately before, at, or very soon after hatching (when individual capsules remained from hatched embryos and when any remnants of dead embryos typically still were visible). We did not assess mortality in any egg masses that had deteriorated too far to evaluate embryos. In 2001, a limited number of field personnel caused us to estimate...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. We conducted a field experiment in 1999 to test for effects of enclosing embryos of A. canorus and moving them to slightly deeper water, thereby reducing the potential for exposure to ice and freezing temperatures, on hatching success at five breeding sites. We split freshly laid egg masses approximately into halves. We left one indiscriminately chosen half of each mass where it was deposited originally (replicates of which were scattered among the shallow waters)...
We produced this data set as part of a larger, integrated study to assess the statuses of populations of Anaxyrus canorus and the causes of observed effects on fitness at field sites, primarily in Yosemite National Park near Tioga Pass, from 1996 to 2001. We assessed the three general categories (early, mid, and late) for the developmental stage at which embryos of A. canorus died among various breeding sites from 1999 to 2001. We visually evaluated each individual embryo in an egg mass in situ while kneeling alongside it immediately before, at, or very soon after hatching (when individual capsules remained from hatched embryos and when any remnants of dead embryos typically still were visible). We did not assess...
    map background search result map search result map Yosemite Toad (Anaxyrus canorus) project datasets; climate, disease, predation, and hatching success data Minimum daily air temperatures (1999 to 2001) and minimum and maximum daily water temperatures next to egg masses (2001) during embryogenesis for Anaxyrus canorus at various breeding sites near Tioga Pass Effects of exposure to ambient UV-B on embryos of Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, in 1996 and 1998 Egg-mass depths for Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, in 1996, 1998, 1999, and 2000 Category for the developmental stage at which embryos of Anaxyrus canorus died at various breeding sites near Tioga Pass, California, USA, from 1999 to 2001 Embryo mortality for Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, from 1996 to 2001 Embryo mortality relative to the abundance category of the water mold, Saprolegnia diclina, and an unidentified predatory flatworm (Turbellaria spp.) for egg masses of Anaxyrus canorus at various breeding sites near Tioga Pass, California, USA, in 2001 Mortality resulting from two field experiments regarding freezing potential for embryos of Anaxyrus canorus at various breeding sites near Tioga Pass, California, USA, in 1999 and 2000 and for one laboratory experiment in 2000 at the Sierra Nevada Aquatic Research Laboratory in Mammoth Lakes, California, USA Yosemite Toad (Anaxyrus canorus) project datasets; climate, disease, predation, and hatching success data Minimum daily air temperatures (1999 to 2001) and minimum and maximum daily water temperatures next to egg masses (2001) during embryogenesis for Anaxyrus canorus at various breeding sites near Tioga Pass Effects of exposure to ambient UV-B on embryos of Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, in 1996 and 1998 Egg-mass depths for Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, in 1996, 1998, 1999, and 2000 Category for the developmental stage at which embryos of Anaxyrus canorus died at various breeding sites near Tioga Pass, California, USA, from 1999 to 2001 Embryo mortality for Anaxyrus canorus and Pseudacris regilla at various breeding sites near Tioga Pass, California, USA, from 1996 to 2001 Embryo mortality relative to the abundance category of the water mold, Saprolegnia diclina, and an unidentified predatory flatworm (Turbellaria spp.) for egg masses of Anaxyrus canorus at various breeding sites near Tioga Pass, California, USA, in 2001 Mortality resulting from two field experiments regarding freezing potential for embryos of Anaxyrus canorus at various breeding sites near Tioga Pass, California, USA, in 1999 and 2000 and for one laboratory experiment in 2000 at the Sierra Nevada Aquatic Research Laboratory in Mammoth Lakes, California, USA