Variable Response of Glaciers to Climate Change in Uttarakhand Himalaya, India

<p><strong>Traditionally, deep-sea ecosystems have been considered to be insulated from the effects of modern climate change. Yet, with the recognition of the importance of food supply from the surface ocean and deep-sea currents to sustaining these systems, the potential for rapid response of benthic systems to climate change is gaining increasing attention. North Atlantic benthic responses to past climate change have been well-documented using marine sediment cores on glacial-interglacial timescales, and ocean sediments have also begun to reveal that planktic species assemblages are already being influenced by global warming. However, very few ecological time-series exist for the deep ocean covering the Holocene-through-industrial era. Here, we use benthic and planktic foraminifera found in Northeast Atlantic (EN539-MC16-A/B and RAPID-17-5P), Northwest Atlantic (KNR158-4-10MC and KNR158-4-9GGC) and Labrador Sea (RAPID-35-25B and RAPID-35-14P) sediments to show that, in locations beneath areas of major North Atlantic surface water change, benthic ecosystems have also changed significantly over the industrial era relative to the Holocene. We find that the response of the benthos is dependent on changes in the surface ocean near to the study sites. Our work highlights the spatial heterogeneity of these benthic ecosystem changes and therefore the need for local-regional scale modelling and observations to better understand responses to deep-sea circulation changes and modern surface climate change.&#160;</strong></p>

Download Full-text

Thermodynamics of cercarial survival and metabolism in a changing climate

Parasitology ◽

10.1017/s0031182011001272 ◽

2011 ◽

Vol 138 (11) ◽

pp. 1442-1452 ◽

Cited By ~ 35

Author(s):

N. J. MORLEY

Keyword(s):

Climate Change ◽

Life Span ◽

Global Climate ◽

Empirical Relationship ◽

Reaction Rates ◽

Sensu Stricto ◽

Life Cycles ◽

Variable Response ◽

Glycogen Store ◽

Response To Temperature

SUMMARYCercariae are non-feeding free-living stages in the life cycles of trematodes, highly influenced by temperature. Their life span is brief, limited by the depletion of a non-renewable glycogen store. Warmer temperatures under the influence of climate change may promote the transmission of parasites and therefore understanding their thermobiology forms an important step in discerning the future dynamics of parasite populations. An empirical relationship exists between cercarial mean expected life span and the half-life of the population (t0·5) and therefore t0·5 is a good indicator of glycogen utilization. In this study experimental data on the effects of temperature on cercarial survival is compiled from the scientific literature and evaluated in terms of metabolism using Q10 and Arrhenius activation energy (E* or μ), common measures of temperature-mediated reaction rates. Cercariae have a variable response to temperature, which does not appear to be influenced by their life-history attributes or size. There were little differences in Q10 and E* values between most temperature ranges. In almost half the studies examined (7 of 16) cercariae demonstrated a discrete zone of thermostability over a range equivalent to typical individual mean summer temperatures. Distinct intraspecific differences in temperature responses between 3 laboratory strains of Schistosoma mansoni and 2 natural strains of Echinoparyphium recurvatumsensu stricto were apparent. The importance of these results for cercarial biology under global climate change is discussed.

Download Full-text

On the response of Himalayan glaciers to climate change

Journal of Glaciology ◽

10.3189/2013jog12j130 ◽

2013 ◽

Vol 59 (215) ◽

pp. 480-490 ◽

Cited By ~ 27

Author(s):

Argha Banerjee ◽

R. Shankar

Keyword(s):

Climate Change ◽

Remote Sensing Data ◽

Variable Response ◽

Numerical Investigations ◽

Rapid Climate Change ◽

Warming Climate ◽

Himalayan Glaciers ◽

Debris Cover ◽

Warming Rate ◽

The Himalaya

AbstractModelling the response of Himalayan glaciers to rapid climate change is an important problem. The poorly understood effects of debris cover and the variable response of the glaciers have made it difficult to understand their dynamics. We propose a simple model for debris-covered glaciers and validate it against data from Dokriani Glacier, India. Numerical investigations of the model show that the response of debris-covered glaciers to a warming climate has two timescales. There is a period when the glacier loses ice by thinning but the front is almost stationary and it develops a long, slow-flowing tongue. This stationary period, which can be >100 years for glaciers with a large extent of debris cover, is negligible for bare glaciers. The quasi-stagnant tongue does not develop in response to cooling. An analysis of remote-sensing data in the light of these results indicates that the variable response of the glaciers in the Himalaya is consistent with a climate that is warming on average, but has considerable spatial variability in the warming rates. We estimate the average warming rate to be about the same as the global average.

Download Full-text

Variable response of anuran calling activity to daily precipitation and temperature: implications for climate change

Ecosphere ◽

10.1890/es12-00258.1 ◽

2013 ◽

Vol 4 (4) ◽

pp. art47 ◽

Cited By ~ 35

Author(s):

Oscar E. Ospina ◽

Luis J. Villanueva-Rivera ◽

Carlos J. Corrada-Bravo ◽

T. Mitchell Aide

Keyword(s):

Climate Change ◽

Daily Precipitation ◽

Variable Response ◽

Calling Activity ◽

Precipitation And Temperature

Download Full-text

Spatially variable response of Himalayan glaciers to climate change affected by debris cover

Nature Geoscience ◽

10.1038/ngeo1068 ◽

2011 ◽

Vol 4 (3) ◽

pp. 156-159 ◽

Cited By ~ 540

Author(s):

Dirk Scherler ◽

Bodo Bookhagen ◽

Manfred R. Strecker

Keyword(s):

Climate Change ◽

Variable Response ◽

Himalayan Glaciers ◽

Debris Cover

Download Full-text

Warm-season heat stress in moose (Alces alces)

Canadian Journal of Zoology ◽

10.1139/cjz-2013-0175 ◽

2013 ◽

Vol 91 (12) ◽

pp. 893-898 ◽

Cited By ~ 28

Author(s):

N.P. McCann ◽

R.A. Moen ◽

T.R. Harris

Keyword(s):

Climate Change ◽

Heat Stress ◽

Alces Alces ◽

Physiological Responses ◽

Warm Season ◽

Thermal Conditions ◽

Gastrointestinal Illness ◽

Variable Response ◽

Respiration Rates ◽

Free Ranging

Understanding how moose (Alces alces (L., 1758)) are affected by temperature is critical for determining why populations have recently declined at the southern extent of their North American range. Warm-season heat-stress thresholds of 14 and 20 °C are commonly used to study moose, but the variable response of free-ranging moose to temperatures above these thresholds suggests that moose may be more tolerant to heat. We studied zoo-managed cow and bull moose to identify factors that influence warm-season heat stress. We found clear behavioral and physiological responses to thermal conditions. Moose selected shade, indicating solar radiation affects heat stress. Temperature and wind influenced respiration rates. Heat-stress thresholds for moose occurred at 17 °C when bedded under calm conditions and 24 °C when bedded under wind, demonstrating that the onset of heat stress is sensitive to wind and incorporating wind velocity into analyses would improve investigations of heat stress. Moose showing symptoms of gastrointestinal illness selected wind at lower temperatures than healthy moose, suggesting the effects of climate change will be compounded for health-compromised moose. Determining why moose are declining at the southern extent of their range may require understanding how temperature interacts with wind, moose health, and other factors.

Download Full-text