Contrasting capabilities of two ungulate species to cope with extremes of aridity

AbstractSouthern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.

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Amazon forest responses to drought: scaling from individuals to ecosystems.

10.5194/egusphere-egu2020-12746 ◽

2020 ◽

Author(s):

Scott R. Saleska ◽

Natalia Restrepo-Coupe ◽

Fernanda V. Barros ◽

Paulo R. L. Bittencourt ◽

Neill Prohaska ◽

...

Keyword(s):

Climate Change ◽

Water Cycle ◽

Ecosystem Respiration ◽

Global Climate ◽

Forest Composition ◽

Future Climate Change ◽

Amazon Forest ◽

Ecosystem Responses ◽

Climate Conditions ◽

Dry Seasons

Scaling from individuals or species to ecosystems is a fundamental challenge of modern ecology and understanding tropical forest response to drought is a key challenge of predicting responses to global climate change.&#160; We here synthesize our developing understanding of these twin challenges by examining individual and ecosystem responses to the 2015 El Ni&#241;o drought at two sites in the central Amazon of Brazil, near Manaus and Santarem, which span a precipitation gradient from moderate (Manaus) to long (Santarem) dry seasons.&#160; We will focus on how ecosystem water and carbon cycling, measured by eddy flux towers, emerges from individual trait-based responses, including photosynthetic responses of individual leaves, and water cycle responses in terms of stomatal conductance and hydraulic xylem embolism resistance.&#160; We found the Santarem forest (with long dry seasons) responded strongly to drought: sensible heat values significantly increased and evapotranspiration decreased.&#160; Consistent with this, we also observed reductions in photosynthetic activity and ecosystem respiration, showing levels of stress not seen in the nearly two decades since measurements started at this site.&#160; Forests at the Manaus site showed significant, however, less consistent reductions in water and carbon exchange and a more pronounced water deficit.&#160; We report an apparent community level forest composition selecting for assemblies of traits and taxa manifest of higher drought tolerance at Santarem, compared to the Manaus forest (short dry seasons) and other forest sites across Amazonia.&#160; These results suggest that we may be able to use community trait compositions (as selected by past climate conditions) and environmental threshold values (e.g. cumulative rainfall, atmospheric moisture and radiation) as to help forecast ecosystem responses to future climate change.

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Future Climate Change Renders Unsuitable Conditions for Paramo Ecosystems in Colombia

Sustainability ◽

10.3390/su12208373 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8373

Author(s):

Matilda Cresso ◽

Nicola Clerici ◽

Adriana Sanchez ◽

Fernando Jaramillo

Keyword(s):

Climate Change ◽

Greenhouse Gas Emission ◽

Dry Season ◽

Capital City ◽

Maximum Temperature ◽

Future Climate Change ◽

Mountain Range ◽

Wet Season ◽

Temperature And Precipitation ◽

The Future

Paramo ecosystems are tropical alpine grasslands, located above 3000 m.a.s.l. in the Andean mountain range. Their unique vegetation and soil characteristics, in combination with low temperature and abundant precipitation, create the most advantageous conditions for regulating and storing surface and groundwater. However, increasing temperatures and changing patterns of precipitation due to greenhouse-gas-emission climate change are threatening these fragile environments. In this study, we used regional observations and downscaled data for precipitation and minimum and maximum temperature during the reference period 1960–1990 and simulations for the future period 2041–2060 to study the present and future extents of paramo ecosystems in the Chingaza National Park (CNP), nearby Colombia’s capital city, Bogotá. The historical data were used for establishing upper and lower precipitation and temperature boundaries to determine the locations where paramo ecosystems currently thrive. Our results found that increasing mean monthly temperatures and changing precipitation will render 39 to 52% of the current paramo extent in CNP unsuitable for these ecosystems during the dry season, and 13 to 34% during the wet season. The greatest loss of paramo area will occur during the dry season and for the representative concentration pathway (RCP) scenario 8.5, when both temperature and precipitation boundaries are more prone to be exceeded. Although our initial estimates show the future impact on paramos and the water security of Bogotá due to climate change, complex internal and external interactions in paramo ecosystems make it essential to study other influencing climatic parameters (e.g., soil, topography, wind, etc.) apart from temperature and precipitation.

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Downscaled Climate Change Projections for Wa District in the Savanna Zone of Ghana

Journal of Disaster Research ◽

10.20965/jdr.2014.p0422 ◽

2014 ◽

Vol 9 (4) ◽

pp. 422-431 ◽

Cited By ~ 7

Author(s):

Emmanuel Tachie-Obeng ◽

◽

Bruce Hewitson ◽

Edwin Akonno Gyasi ◽

Mark Kofi Abekoe ◽

...

Keyword(s):

Climate Change ◽

Local Level ◽

Control Period ◽

Dry Season ◽

Future Climate ◽

Future Climate Change ◽

Wet Season ◽

Annual Variations ◽

Near Future ◽

Savanna Zone

The possibility of future climate change in Ghana has received much attention due to repeated droughts and floods over the last decades. The savanna zone which is described as the food basket of Ghana is highly susceptible to climate change impact. Scenarios from 20-year time slices of the near future – 2046-2065 – and the far future – 2081-2100 – climate change meant to help guide policy remain a challenge. Empirical downscaling performed at the local-scale of Wa District in the savanna zone of Ghana under the IPCC A2 SRES emissions scenario showed evidence of probable climate change with mean annual temperatures expected to increase over an estimated range of 1.5°C to 2.3°C in the near future, with number of cool nights becoming less frequent, especially during the Harmattan1 period. The dry season is expected to be warmer than the wet season, with high inter-annual variations projected in both maximum (Tmax) and minimum (Tmin) temperatures. Given an average of 1 day of Tmax > 40°C per month in the control period of 1961-2000, the number of hot days is expected to increase to 12 by 2046-2065. An increase in total rainfall is projected with possible shifts in distribution toward the end of the year, with a slight increase in rainfall during the dry season and an increase of rainfall at the onset and toward the end of the wet season. However, a decrease in June rainfall is projected in the wet season. The objective of this paper is to improve the understanding of future climate as a guide to local level medium-term development plans of effective adaptation options for Wa district in the savanna zone of Ghana.

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Future projections of High Atlas snowpack and runoff under climate change

10.5194/hess-2020-622 ◽

2020 ◽

Author(s):

Alexandre Tuel ◽

Nabil El Moçayd ◽

Moulay Driss Hasnaoui ◽

Elfatih A. B. Eltahir

Keyword(s):

Climate Change ◽

River Discharge ◽

River Flow ◽

Climate Modeling ◽

Large Fraction ◽

Future Climate Change ◽

Wet Season ◽

High Atlas ◽

Snow Model ◽

Stressed Region

Abstract. The High Atlas, culminating at more than 4000 m, is the water tower of Morocco. While plains receive less than 400 mm of precipitation in an average year, the mountains can get twice as much, often in the form of snow between November and March. Snowmelt thus accounts for a large fraction of the river discharge in the region, and is particularly critical during spring, as the wet season ends but the need for irrigation increases. In the same region, future climate change projections point towards a significant decline in precipitation and enhanced warming of temperature. Understanding how the High Atlas snowpack will evolve under such trends is therefore of paramount importance to make informed projections of future water availability in Morocco. Here, we build on previous research results on snow and climate modeling in the High Atlas to make detailed projections of snowpack and river flow response to climate change in this region. Using a distributed energy balance snow model based on SNOW-17, high-resolution climate simulations over Morocco, and a panel regression framework to relate runoff ratios to regional meteorological conditions, we quantify the severe declines in snowpack and river discharge that are to be expected, even under a scenario of substantial mitigation of emissions. Our results have important implications for water resources planning and sustainability of agriculture in this already water-stressed region.

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Analyzing Land Use Impacts on Streamflow Response in a Tropical Watershed: A Hydrometric and Geochemical Approach

10.5194/egusphere-egu2020-1211 ◽

2020 ◽

Author(s):

Nicola Mathura ◽

Kegan Farrick

Keyword(s):

Climate Change ◽

Land Use ◽

Critical Zone ◽

Dry Season ◽

Future Climate Change ◽

Wet Season ◽

Forested Catchment ◽

Streamflow Response ◽

The Caribbean ◽

Geochemical Approach

Climate change and unsustainable land use practices such as quarrying have the potential to negatively impact the hydrology and water resource availability in catchments. Throughout the Caribbean, hillside quarrying has become a common practice. While these activities remove large sections of the critical zone, very little work has been done on how hillside quarrying impacts storm response and catchment water storage. &#160;The study is particularly important given the expected changes to rainfall patterns in the Caribbean under future climate change. We hypothesised that the removal of the critical zone during quarrying will increase the magnitude of streamflow response to storm events due to its close proximity to the river, while also reducing the overall storage of the watershed. This study utilized a hydrometric and geochemical approach with direct measurements of rainfall and streamflow, and bi-weekly water sample collections for geochemistry and 18O and 2H stable isotopes between the 3.6 km2 Acono (forested) and the adjacent 3.6 km2 Don Juan (quarried) watersheds, located in Trinidad and Tobago. A total of 1207 mm of rainfall occurred, with 87.3% falling from August to November (wet season) and 12.7% from December to March (dry season). The &#948; 18O in rainfall ranged from -7.7 to 0.3 &#8240; across both seasons with an average &#948;18O of -3.5&#177;1.8&#8240; during the wet season and 0.1&#177;0.5&#8240; in the dry season. During the dry season the mean &#948; 18O of stream water showed a difference between the forested (-2.8&#177;0.3&#8240;) and quarried (-3.1&#177;0.3&#8240;) catchments whereas there was little differences in &#948;18O in the forested catchment (-3.3&#177;0.3 &#8240;) and quarried catchment&#8211;(-3.2&#177;0.27&#8240;) in the wet season. Our stream &#948;18O dry season results suggests that different sources of water or anthropogenic influences such as water from settling ponds in the quarry could have impacted the &#948;18O of the quarried stream as we expected the forested catchment to be more stable. Sample collection at these sites is ongoing and additional parameters such as soil water isotopes and rainfall, soil and stream ion chemistry are expected to improve our understanding of the translation from rainfall to streamflow. This research will allow us to gain a better insight of the current hydrological processes within this catchment and aid in the long term adaptive planning for factors such as climate change and further land use change.&#160;

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Thermal ecology of the federally endangered blunt-nosed leopard lizard (Gambelia sila)

Conservation Physiology ◽

10.1093/conphys/coaa014 ◽

2020 ◽

Vol 8 (1) ◽

Cited By ~ 3

Author(s):

Kathleen N Ivey ◽

Margaret Cornwall ◽

Hayley Crowell ◽

Nargol Ghazian ◽

Emmeleia Nix ◽

...

Keyword(s):

Climate Change ◽

Endangered Species ◽

Thermal Tolerance ◽

Microhabitat Use ◽

Thermal Ecology ◽

Body Temperatures ◽

Ambient Temperatures ◽

Open Habitat ◽

Kangaroo Rat ◽

Upper Thermal Tolerance

Abstract Recognizing how climate change will impact populations can aid in making decisions about approaches for conservation of endangered species. The blunt-nosed leopard lizard (Gambelia sila) is a federally endangered species that, despite protection, remains in extremely arid, hot areas and may be at risk of extirpation due to climate change. We collected data on the field-active body temperatures, preferred body temperatures and upper thermal tolerance of G. sila. We then described available thermal habitat using biophysical models, which allowed us to (i) describe patterns in lizard body temperatures, microhabitat temperatures and lizard microhabitat use; (ii) quantify the lizards’ thermoregulatory accuracy; (iii) calculate the number of hours they are currently thermally restricted in microhabitat use; (iv) project how the number of restricted hours will change in the future as ambient temperatures rise; and (v) assess the importance of giant kangaroo rat burrows and shade-providing shrubs in the current and projected future thermal ecology of G. sila. Lizards maintained fairly consistent daytime body temperatures over the course of the active season, and use of burrows and shrubs increased as the season progressed and ambient temperatures rose. During the hottest part of the year, lizards shuttled among kangaroo rat burrows, shrubs, and open habitat to maintain body temperatures below their upper thermal tolerance, but, occasionally, higher than their preferred body temperature range. Lizards are restricted from staying in the open habitat for 75% of daylight hours and are forced to seek refuge under shrubs or burrows to avoid surpassing their upper thermal threshold. After applying climatic projections of 1 and 2°C increases to 2018 ambient temperatures, G. sila will lose additional hours of activity time that could compound stressors faced by this population, potentially leading to extirpation.

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Foraging Ecology and Diurnal Activity Patterns of Klipspringer (Oreotragus oreotragus) in Yetefet Woyenat Forest, East Gojjam, Ethiopia

International Journal of Zoology ◽

10.1155/2020/4930915 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Melaku Bireda ◽

Mesele Yihune

Keyword(s):

Foraging Ecology ◽

Activity Patterns ◽

Early Morning ◽

Visual Observation ◽

Diurnal Activity ◽

Wet Season ◽

Ambient Temperatures ◽

Dry Seasons ◽

Trees And Shrubs ◽

Wet And Dry Seasons

The foraging ecology and diurnal activity patterns of the klipspringer (Oreotragus oreotragus) were studied in Yetefet Woyenat Forest from September 2017 to August 2018 during the dry and wet seasons. Data were collected by visual observation using focal and scan sampling methods. The result indicated that klipspringers were observed feeding on grasses, herbs, trees, and shrubs, but were primarily browsers during both wet and dry seasons. Carissa edulis was the most consumed plant species in the study area, followed by Rosa abyssinica and Maytenus arbutifolia. Despite moderate ambient temperatures, klipspringers were mostly active during early morning and late afternoon, feeding 45.56% of the daylight hours during the dry season and 43.75% during the wet season. Klipspringers were facing threats due to human activities in the study area. Thus, appropriate conservation measures should be taken to reduce disturbance of their ecology.

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Ecology of Frillneck Lizards, Chlamydosaurus-Kingii (Agamidae), in Tropical Australia

Wildlife Research ◽

10.1071/wr9890491 ◽

1989 ◽

Vol 16 (5) ◽

pp. 491 ◽

Cited By ~ 22

Author(s):

R Shine ◽

R Lambeck

Keyword(s):

Activity Patterns ◽

Common Species ◽

Body Temperatures ◽

Wet Season ◽

Ambient Temperatures ◽

Air Temperatures ◽

Highly Correlated ◽

Vantage Points ◽

Reproductive Cycles ◽

Free Ranging

Radiotelemetric monitoring of 18 free-ranging frillneck lizards in Kakadu National Park, combined with dissection of museum specimens, provided extensive data on the natural history and general ecology of this large and spectacular lizard. Activity patterns and reproductive cycles are highly seasonal, with lizards inactive during the drier (and cooler) months of the year. Frillnecks are primarily arboreal and are relatively unselective with regard to the species of tree used except that one common species, Eucalyptus confertyora, is avoided. Telemetered lizards usually clung to branches high in the canopy. During the mating season (November-December), males had larger activity ranges than did females (means of 2.5 vs 0.7 ha) and made longer daily movements (means of 69 vs 23 m). Frillneck lizards bask briefly in the morning, but body temperatures follow ambient temperatures for most of the day. Thermal heterogeneity in the lizards' habitat is low, so opportunities for behavioural regulation (especially reduction) of body temperature are limited. Body temperatures are highly correlated with air temperatures and are often close to 40�C. Female frillnecks are considerably smaller than males, and they produce 4-13 eggs during the wet season. Chlamydosaurus are apparently unique among reptiles in using bipedal locomotion during routine foraging. These lizards are 'sit and wait' predators, descending from arboreal vantage points to seize lepidopteran larvae or massed swarms of hymenopteran or isopteran alates. Many different types of insects are eaten, but vertebrate prey items are rarely taken.

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Testing the heat dissipation limitation hypothesis: basal metabolic rates of endotherms decrease with increasing upper and lower critical temperatures

PeerJ ◽

10.7717/peerj.5725 ◽

2018 ◽

Vol 6 ◽

pp. e5725 ◽

Cited By ~ 1

Author(s):

Imran Khaliq ◽

Christian Hof

Keyword(s):

Climate Change ◽

Heat Dissipation ◽

Climatic Conditions ◽

Future Climate Change ◽

Metabolic Rates ◽

Critical Temperatures ◽

Ambient Temperatures ◽

Species Vulnerability ◽

Vulnerability To Climate Change ◽

The Relationship

Metabolic critical temperatures define the range of ambient temperatures where endotherms are able to minimize energy allocation to thermogenesis. Examining the relationship between metabolic critical temperatures and basal metabolic rates (BMR) provides a unique opportunity to gain a better understanding of how animals respond to varying ambient climatic conditions, especially in times of ongoing and projected future climate change. We make use of this opportunity by testing the heat dissipation limit (HDL) theory, which hypothesizes that the maximum amount of heat a species can dissipate constrains its energetics. Specifically, we test the theory’s implicit prediction that BMR should be lower under higher metabolic critical temperatures. We analysed the relationship of BMR with upper and lower critical temperatures for a large dataset of 146 endotherm species using regression analyses, carefully accounting for phylogenetic relationships and body mass. We show that metabolic critical temperatures are negatively related with BMR in both birds and mammals. Our results confirm the predictions of the HDL theory, suggesting that metabolic critical temperatures and basal metabolic rates respond in concert to ambient climatic conditions. This implies that heat dissipation capacities of endotherms may be an important factor to take into account in assessments of species’ vulnerability to climate change.

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