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Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness.

Nusslé S, Matthews KR, Carlson SM - PLoS ONE (2015)

Bottom Line: Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure.In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow.Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science, Policy & Management, University of California, Berkeley, California, United States of America.

ABSTRACT
Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two "resting" meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw), which have been in a "resting" state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

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Temperature predictions under four climatic scenarios.The four climate warming scenarios represent: (1) the current situation, (2) a moderate increase of 1°C in air temperature, (3) a more realistic scenario of 3.7°C increase in air temperature, and (4) the worst-case scenario for the U.S.A., with a 5.6°C increase in air temperature. The boxplots represents, for each meadow and each scenario, the expected maximal temperature (DmaxT) (black line), the 50% prediction interval, i.e., the maximal temperatures expected every other year (box), the 95% prediction interval, i.e., the maximal temperatures (DmaxT) expected every twenty years (upper whiskers), and the 99% prediction interval, i.e., the maximal temperatures (DmaxT) expected every one hundred years (upper circle).
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pone.0142426.g007: Temperature predictions under four climatic scenarios.The four climate warming scenarios represent: (1) the current situation, (2) a moderate increase of 1°C in air temperature, (3) a more realistic scenario of 3.7°C increase in air temperature, and (4) the worst-case scenario for the U.S.A., with a 5.6°C increase in air temperature. The boxplots represents, for each meadow and each scenario, the expected maximal temperature (DmaxT) (black line), the 50% prediction interval, i.e., the maximal temperatures expected every other year (box), the 95% prediction interval, i.e., the maximal temperatures (DmaxT) expected every twenty years (upper whiskers), and the 99% prediction interval, i.e., the maximal temperatures (DmaxT) expected every one hundred years (upper circle).

Mentions: When we do not include warming, our model predicts that the maximal temperature (DmaxT) in Mulkey should reach on average 25.9°C, but could reach, in some parts of the river, 27.3°C every other year and 29.9°C every twenty years (Table 4 and Fig 7), which is consistent with the observed daily maximal temperature (DmaxT) that reached 26.3°C in Mulkey Meadows. In Ramshaw, the maximal temperature (DmaxT) modeled should reach 21.7°C on average, 23.1°C every other year, and 25.7°C every twenty years (Table 4, Fig 7), compared to the observed daily maximal temperature (DmaxT) which reached 25.5°C in Ramshaw meadow. Finally, in Big Whitney, the maximal temperature (DmaxT) modeled should reach 17.2°C on average, 18.6°C every other year, and 21.2°C every twenty years (Table 4, Fig 7), compared to the observed daily maximal temperature (DmaxT) of 21.2°C in Big Whitney meadow. If we consider the most optimistic scenario, i.e. a global temperature elevation of “only” 1°C by the end of the century (i.e., 0.5°C for the water temperature), our model predicts that the maximal temperature (DmaxT) reached in Mulkey could reach 28.1°C every other year in the warmest parts of the river (23.9°C in Ramshaw; 19.5°C in Big Withney) and 30.8°C every twenty years (26.5°C in Ramshaw; 22.1°C in Big Withney). With a more realistic scenario of global warming, i.e., a global temperature elevation of 3.7°C (i.e., 1.8°C in rivers), our model predicts that some parts of the river could reach 30.4°C every other year (26.1°C in Ramshaw; 21.7°C in Big Withney) and 33.0°C every twenty years (28.7°C in Ramshaw; 24.3°C in Big Withney). Modeled temperatures in the three meadows are summarized in Table 4 and Fig 7.


Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness.

Nusslé S, Matthews KR, Carlson SM - PLoS ONE (2015)

Temperature predictions under four climatic scenarios.The four climate warming scenarios represent: (1) the current situation, (2) a moderate increase of 1°C in air temperature, (3) a more realistic scenario of 3.7°C increase in air temperature, and (4) the worst-case scenario for the U.S.A., with a 5.6°C increase in air temperature. The boxplots represents, for each meadow and each scenario, the expected maximal temperature (DmaxT) (black line), the 50% prediction interval, i.e., the maximal temperatures expected every other year (box), the 95% prediction interval, i.e., the maximal temperatures (DmaxT) expected every twenty years (upper whiskers), and the 99% prediction interval, i.e., the maximal temperatures (DmaxT) expected every one hundred years (upper circle).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4643935&req=5

pone.0142426.g007: Temperature predictions under four climatic scenarios.The four climate warming scenarios represent: (1) the current situation, (2) a moderate increase of 1°C in air temperature, (3) a more realistic scenario of 3.7°C increase in air temperature, and (4) the worst-case scenario for the U.S.A., with a 5.6°C increase in air temperature. The boxplots represents, for each meadow and each scenario, the expected maximal temperature (DmaxT) (black line), the 50% prediction interval, i.e., the maximal temperatures expected every other year (box), the 95% prediction interval, i.e., the maximal temperatures (DmaxT) expected every twenty years (upper whiskers), and the 99% prediction interval, i.e., the maximal temperatures (DmaxT) expected every one hundred years (upper circle).
Mentions: When we do not include warming, our model predicts that the maximal temperature (DmaxT) in Mulkey should reach on average 25.9°C, but could reach, in some parts of the river, 27.3°C every other year and 29.9°C every twenty years (Table 4 and Fig 7), which is consistent with the observed daily maximal temperature (DmaxT) that reached 26.3°C in Mulkey Meadows. In Ramshaw, the maximal temperature (DmaxT) modeled should reach 21.7°C on average, 23.1°C every other year, and 25.7°C every twenty years (Table 4, Fig 7), compared to the observed daily maximal temperature (DmaxT) which reached 25.5°C in Ramshaw meadow. Finally, in Big Whitney, the maximal temperature (DmaxT) modeled should reach 17.2°C on average, 18.6°C every other year, and 21.2°C every twenty years (Table 4, Fig 7), compared to the observed daily maximal temperature (DmaxT) of 21.2°C in Big Whitney meadow. If we consider the most optimistic scenario, i.e. a global temperature elevation of “only” 1°C by the end of the century (i.e., 0.5°C for the water temperature), our model predicts that the maximal temperature (DmaxT) reached in Mulkey could reach 28.1°C every other year in the warmest parts of the river (23.9°C in Ramshaw; 19.5°C in Big Withney) and 30.8°C every twenty years (26.5°C in Ramshaw; 22.1°C in Big Withney). With a more realistic scenario of global warming, i.e., a global temperature elevation of 3.7°C (i.e., 1.8°C in rivers), our model predicts that some parts of the river could reach 30.4°C every other year (26.1°C in Ramshaw; 21.7°C in Big Withney) and 33.0°C every twenty years (28.7°C in Ramshaw; 24.3°C in Big Withney). Modeled temperatures in the three meadows are summarized in Table 4 and Fig 7.

Bottom Line: Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure.In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow.Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science, Policy & Management, University of California, Berkeley, California, United States of America.

ABSTRACT
Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two "resting" meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw), which have been in a "resting" state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

Show MeSH
Related in: MedlinePlus