scholarly journals Quantifying Climate-Wise Connectivity across a Topographically Diverse Landscape

Land ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 355 ◽  
Author(s):  
Morgan Gray ◽  
Elisabeth Micheli ◽  
Tosha Comendant ◽  
Adina Merenlender
Keyword(s):  
Climate Adaptation ◽  
Temperature Gradients ◽  
Range Shifts ◽  
Temperature Extremes ◽  
Improved Method ◽  
The West ◽  
Biologically Relevant ◽  
Summer Maximum ◽  
Suitable Habitats ◽  
Large Water

Climate-wise connectivity is essential to provide species access to suitable habitats in the future, yet we lack a consistent means of quantifying climate adaptation benefits of habitat linkages. Species range shifts to cooler climates have been widely observed, suggesting we should protect pathways providing access to cooler locations. However, in topographically diverse regions, the effects of elevation, seasonality, and proximity to large water bodies are complex drivers of biologically relevant temperature gradients. Here, we identify potential terrestrial and riparian linkages and their cooling benefit using mid-century summer and winter temperature extremes for interior coastal ranges in Northern California. It is rare for the same area to possess both terrestrial and riparian connectivity value. Our analysis reveals distinct differences in the magnitude and orientation of cooling benefits between the summer maximum and winter minimum temperatures provided by the linkages we delineated for the area. The cooling benefits for both linkage types were maximized to the west during summer, but upslope and to the northeast during winter. The approach we employ here provides an improved method to prioritize climate-wise connectivity and promote landscape resilience for topographically diverse regions.

scholarly journals Update of distribution, habitats, population size, and threat factors for the West African crocodile in Mauritania

2016 ◽  
Vol 37 (3) ◽  
pp. 325-330 ◽  
Author(s):  
João Carlos Campos ◽  
Fernando Martínez-Freiría ◽  
Fábio Vieira Sousa ◽  
Frederico Santarém ◽  
José Carlos Brito
Keyword(s):  
Population Size ◽  
Conservation Status ◽  
West African ◽  
Conservation Strategies ◽  
Temperature Extremes ◽  
Local Conservation ◽  
The West ◽  
Water Abstraction ◽  
New Localities ◽  
Domestic Use

The West African crocodile (Crocodylus suchus) is an emblematic species from the Sahara-Sahel with scarce knowledge on distribution and conservation status. This study updated the knowledge on distribution, occupied habitats, population size, and factors that threaten C. suchus and its habitats in Mauritania. Five field expeditions to Mauritania (2011-2016), allowed the detection of 26 new localities, increasing by 27% the current number of all known locations (adding up to ). In most localities less than five individuals were observed, and in all visiting sites the number of observed individuals ranged from one to 23. Eleven threat factors were identified, being droughts and temperature extremes (100% localities affected) and water abstraction for domestic use and nomadic grazing (94%) the most frequent. These findings suggest that crocodiles are apparently vulnerable in Mauritania and that future local conservation strategies are needed to assure the continuity of its fragile populations and preserve their habitats.

Spatiotemporal Variation in ΔR on the West Coast of North America in the Late Holocene: Implications for Dating the Shells of Marine Mollusks

2020 ◽  
Vol 85 (4) ◽  
pp. 676-693
Author(s):  
Ian Hutchinson
Keyword(s):  
North America ◽  
West Coast ◽  
Late Holocene ◽  
Southern Oscillation ◽  
Tidal Energy ◽  
Spatiotemporal Resolution ◽  
The West ◽  
Summer Maximum ◽  
High Alkalinity ◽  
High Degree

Radiocarbon ages on mollusk shells, which account for about half of the more than 8,000 dates from cultural deposits on the west coast of North America, need to be corrected for the local marine reservoir effect (ΔR) to yield true ages. Assays on “prebomb” shells show that ΔR increases poleward, echoing the age gradient in offshore waters. The meridional gradient in ΔR is not appreciably affected by the transition either from an upwelling regime to a downwelling regime north of 40°N–45°N or from a winter maximum-high alkalinity river discharge pattern to a summer maximum-low alkalinity pattern at the same latitude, probably because these changes are offset by increasing storminess and tidal energy in coastal areas. Mesoscale variations in ΔR along this gradient are attributable to contrasts in shore morphology and exposure. Data from 123 shell-wood pairs reveal similar patterns of temporal variation in ΔR in the late Holocene in the coastal ecoregions. The characteristic temporal pattern echoes phases of variable El Niño-Southern Oscillation (ENSO) activity. The high degree of variability in ΔR argues against the indiscriminate application of regionally uniform or trans-Holocene ΔR values and demands improvements in spatiotemporal resolution if shell is used to date cultural deposits.

scholarly journals Will population exposure to heat extremes intensify over Southeast Asia in a warmer world?

2022 ◽  
Author(s):  
Xuerong Sun ◽  
Fei Ge ◽  
Yi Fan ◽  
Shoupeng Zhu ◽  
Quanliang Chen
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Southeast Asia ◽  
Climate Adaptation ◽  
Coupled Model ◽  
The Philippines ◽  
Mitigation Strategies ◽  
Population Exposure ◽  
Temperature Extremes ◽  
Heat Extremes

Abstract Temperature extremes have increased during the past several decades and are expected to intensify under current rapid global warming over Southeast Asia (SEA). Exposure to rising temperatures in highly vulnerable regions affects populations, ecosystems, and other elements that may suffer potential losses. Here, we evaluate changes in temperature extremes and future population exposure over SEA at global warming levels (GWLs) of 2.0 °C and 3.0 °C using outputs from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Results indicate that temperature extreme indices are projected to increase over SEA at both GWLs, with more significant magnitudes at 3.0 °C. However, daily temperature ranges (DTR) show a decrease. The substantial increase in total SEA population exposure to heat extremes from 730 million person-days at 2.0 °C GWL to 1,200 million person-days at 3.0 °C GWL is mostly contributed by the climate change component, accounting for 48%. In addition, if the global warming is restricted well below 2.0 °C, the avoided impacts in population exposure are prominent for most regions over SEA with the largest mitigation in the Philippines (PH). Aggregate population exposure to impacts is decreased by approximately 39% at 2.0 °C GWL, while the interaction component effect, which is associated with increased population and climate change, would decrease by 53%. This indicates the serious consequences for growing populations concurrent with global warming impacts if the current fossil-fueled development pathway is adhered to. The present study estimates the risks of increased temperature extremes and population exposure in a warmer future, and further emphasizes the necessity and urgency of implementing climate adaptation and mitigation strategies in SEA.

The Non-Gaussianity and Spatial Asymmetry of Temperature Extremes Relative to the Storm Track: The Role of Horizontal Advection

2017 ◽  
Vol 30 (2) ◽  
pp. 445-464 ◽  
Author(s):  
Chaim I. Garfinkel ◽  
Nili Harnik
Keyword(s):  
General Circulation ◽  
Extreme Temperature ◽  
Storm Track ◽  
Reanalysis Data ◽  
Temperature Extremes ◽  
Tropospheric Temperature ◽  
Positive Temperature ◽  
The West ◽  
Near Surface ◽  
Temperature Advection

The distribution of near-surface and tropospheric temperature variability in midlatitudes is distinguishable from a Gaussian in meteorological reanalysis data; consistent with this, warm extremes occur preferentially poleward of the location of cold extremes. To understand the factors that drive this non-Gaussianity, a dry general circulation model and a simple model of Lagrangian temperature advection are used to investigate the connections between dynamical processes and the occurrence of extreme temperature events near the surface. The non-Gaussianity evident in reanalysis data is evident in the dry model experiments, and the location of extremes is influenced by the location of the jet stream and storm track. The cause of this in the model can be traced back to the synoptic evolution within the storm track leading up to cold and warm extreme events: negative temperature extremes occur when an equatorward propagating high–low couplet (high to the west) strongly advects isotherms equatorward over a large meridional fetch over more than two days. Positive temperature anomalies occur when a poleward propagating low–high couplet (low to the west) advects isotherms poleward over a large meridional fetch over more than two days. The magnitude of the extremes is enhanced by the meridional movement of the systems. Overall, horizontal temperature advection by storm track systems can account for the warm/cold asymmetry in the latitudinal distribution of the temperature extremes.

Polar cap sporadic E

1969 ◽  
Vol 47 (8) ◽  
pp. 931-948 ◽  
Author(s):  
N. C. Gerson
Keyword(s):  
Auroral Oval ◽  
Skewed Distribution ◽  
The Arctic ◽  
Similar Data ◽  
The West ◽  
Secondary Maximum ◽  
Geomagnetic Pole ◽  
Summer Maximum ◽  
Resolute Bay ◽  
Sporadic E

Backscatter probings (at 28 MHz) of the arctic ionosphere were made at Alert, Canada, for almost two years. A skewed distribution around the site was found with (a) maximum occurrences constrained to the northeast within ±30° of the great circle through Alert and the principal northern magnetic dip pole, (b) a secondary maximum to the south, and (c) a marked dearth of observations as a tongue from the west (250°–280°) to about 800 km in the east. The annual pattern was almost identical with the summer and winter patterns. Equinoctial distributions were distinct. The maximum broadened to include the sector in the northeast within the great circles passing through Alert and the dip pole, and Alert and the geomagnetic pole. The secondary maximum and the tongue from the west of very low occurrences vanished.Seasonally, a pronounced maximum was found in the period June–August, and a weak secondary maximum during the equinoctial months. Diurnally, activity was present from 0700–1900 LST with a single peak near 1300 LST. Slight deviations from this pattern were noted in winter and summer. In the equinoxes, a plateau or double peak seemed present in the afternoon.Returns from the azimuth of Thule correlated with vertical-incidence sporadic E frequencies from Thule multiplied by the secant factor. No correlation with similar data from Resolute Bay was present. Indications of direct backscatter from field-aligned irregularities were found despite the large angles off perpendicularity. Es occurrences, after a lag of 1–2 days, seemed to be associated with appreciable increases in the daily value of ap. None of the results were predicted by standard maximum usable frequency prediction procedures.Two mechanisms seem possible for clarifying the results: (a) for the summer maximum, the Es layer tilted upwards to the principal northern dip pole; and (b) for the secondary equinoctial maximum, the daily swing of the auroral oval through the antenna beamwidth.

Controls on range shifts of coastal Californian bivalves during the peak of the last interglacial and baseline predictions for today

Paleobiology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Emily A. Orzechowski ◽  
Seth Finnegan
Keyword(s):  
Coastal Waters ◽  
Recent Time ◽  
Range Shifts ◽  
Bivalve Species ◽  
Last Interglacial ◽  
High Dispersal ◽  
Suitable Habitats ◽  
Mis 5E ◽  
Near Future ◽  
Water Species

Abstract As the most recent time in Earth history when global temperatures were warmer than at present, the peak of the last interglacial (Marine Isotope Substage [MIS] 5e; ~120,000 years ago) can serve as a pre-anthropogenic baseline for a warmer near-future world. Here we use a new compilation of 22 fossil localities in California that have been reliably dated to MIS 5e to establish baseline expectations for contemporary bivalve species movements by identifying and analyzing bivalve species with “extralimital” ranges, that is, species that occupied the California region during MIS 5e but are now restricted to adjacent regions. We find that 15% of species (n = 142) found in MIS 5e localities have extralimital ranges and currently occupy warmer waters to the south of the California region. The majority of extralimital occurrences occur in paleo-embayments, suggesting that these sheltered habitats were more suitable habitats for warm-water species than exposed coasts during the MIS 5e. We further find that extralimital species now tend to occur in cooler, more seasonally productive coastal waters and to occupy more offshore islands when compared with the broader species pool immediately south of California. These findings suggest that high dispersal potential and preexisting tolerances to environmental conditions similar to California's comparatively cool and seasonally productive environments may have enabled extralimital bivalves to colonize the California region during MIS 5e.

scholarly journals Selecting tree species for climate change integrated forest restoration and management in the Chitwan Annapurna Landscape, Nepal

2020 ◽  
Vol 13 ◽  
pp. 29-46
Author(s):  
Gokarna Jung Thapa ◽  
Eric Wikramanayake
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Forest Restoration ◽  
Climate Adaptation ◽  
Range Shifts ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Government ◽  
Choice Of Species

Climate change will affect forest vegetation communities, and field surveys have already indicated measurable distribution range shifts in some tree species. As forests play an important role in stabilizing steep slopes and provide vital ecological goods and services, the Government of Nepal has been encouraging forest restoration and sustainable management. However, reforestation and afforestation programs should consider the long term survivorship of the trees selected for reforestation to build climate adaptation and resilience. Thus, the choice of species should include species that would be expected to grow within the elevation zone or in the particular habitat under future climate change scenarios. In this analysis, we have assessed the response of 12 important tree species to climate change using the IPCC A2A GHG scenario with GCM-based climate envelopes to provide guidelines and recommendations for climate change-integrated forest restoration and management in the Chitwan-Annapurna Landscape (CHAL). The results indicate that several species could exhibit range shifts due to climate change, with an overall trend for species in the lower elevations to move northwards or further up the slopes within the current area of distributions. Analyses such as this, though not perfect, can help to make critical and informed decisions to support long-term forest restoration programs.

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