scholarly journals Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10856
Author(s):  
Molly Moroz ◽  
Illiam S.C. Jackson ◽  
Daniel Ramirez ◽  
Melissa E. Kemp

How species will respond to ongoing and future climate change is one of the most important questions facing biodiversity scientists today. The fossil record provides unparalleled insight into past ecological and evolutionary responses to climate change, but the resource remains virtually untapped for many organisms. We use geometric morphometrics and a 25,000 year fossil record to quantify changes in body size and mandible shape through time and across climate regimes for two bat species present in Quaternary paleontological deposits of central Texas: Myotis velifer, a bat distributed throughout the Southwestern US and Mexico that is still found in central Texas today, and Eptesicus fuscus, a bat widely distributed throughout North America that has been extirpated in central Texas. Because of ecogeographic rules like Bergmann’s rule, which posits that endotherms are larger in colder environments, we hypothesized that both species were larger during cooler time intervals. Additionally, we hypothesized that both species would show variation in dental morphology across the studied sequence as a response to climate change. While we found a decrease in centroid size–a proxy for ­­body size–through time for both species, we could not establish a clear relationship between centroid size and temperature alone. However, we did find that specimens from drier environments were significantly larger than those from wetter ones. Furthermore, we found significant dental shape variation between environments reflecting different temperature levels for both species. Yet only M. velifer exhibited significant variation between environments of varying precipitation levels. This result was surprising because present-day populations of E. fuscus are highly variable across both temperature and precipitation gradients. We determined that the morphological change experienced by M. velifer through time, and between warmer and cooler temperatures, was associated with the coronoid process, condylar process, and the mandibular symphysis. These parts play a pivotal role in bite force, so changes in these features might relate to changes in diet. We show that long-term datasets derived from fossil material provide invaluable insight not only into the validity of ecogeographic rules, but also into the adaptive capacities of extant taxa when faced with environmental changes. Our results highlight diverging responses to a variety of climate factors that are relevant to consider in biodiversity research given ongoing global change.

Author(s):  
S. Supharatid ◽  
J. Nafung ◽  
T. Aribarg

Abstract Five mainland SEA countries (Cambodia, Laos, Myanmar, Vietnam, and Thailand) are threatened by climate change. Here, the latest 18 Coupled Model Intercomparison Project Phase 6 (CMIP6) is employed to examine future climate change in this region under two SSP-RCP (shared socioeconomic pathway-representative concentration pathway) scenarios (SSP2-4.5 and SSP5-8.5). The bias-corrected multi-model ensemble (MME) projects a warming (wetting) over Cambodia, Laos, Myanmar, Vietnam, and Thailand by 1.88–3.89, 2.04–4.22, 1.88–4.09, 2.03–4.25, and 1.90–3.96 °C (8.76–20.47, 12.69–21.10, 9.54–21.10, 13.47–22.12, and 7.03–15.17%) in the 21st century with larger values found under SSP5-8.5 than SSP2-4.5. The MME model displays approximately triple the current rainfall during the boreal summer. Overall, there are robust increases in rainfall during the Southwest Monsoon (3.41–3.44, 8.44–9.53, and 10.89–17.59%) and the Northeast Monsoon (−2.58 to 0.78, −0.43 to 2.81, and 2.32 to 5.45%). The effectiveness of anticipated climate change mitigation and adaptation strategies under SSP2-4.5 results in slowing down the warming trends and decreasing precipitation trends after 2050. All these findings imply that member countries of mainland SEA need to prepare for appropriate adaptation measures in response to the changing climate.


2020 ◽  
Vol 12 (4) ◽  
pp. 2959-2970
Author(s):  
Maialen Iturbide ◽  
José M. Gutiérrez ◽  
Lincoln M. Alves ◽  
Joaquín Bedia ◽  
Ruth Cerezo-Mota ◽  
...  

Abstract. Several sets of reference regions have been used in the literature for the regional synthesis of observed and modelled climate and climate change information. A popular example is the series of reference regions used in the Intergovernmental Panel on Climate Change (IPCC) Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Adaptation (SREX). The SREX regions were slightly modified for the Fifth Assessment Report of the IPCC and used for reporting subcontinental observed and projected changes over a reduced number (33) of climatologically consistent regions encompassing a representative number of grid boxes. These regions are intended to allow analysis of atmospheric data over broad land or ocean regions and have been used as the basis for several popular spatially aggregated datasets, such as the Seasonal Mean Temperature and Precipitation in IPCC Regions for CMIP5 dataset. We present an updated version of the reference regions for the analysis of new observed and simulated datasets (including CMIP6) which offer an opportunity for refinement due to the higher atmospheric model resolution. As a result, the number of land and ocean regions is increased to 46 and 15, respectively, better representing consistent regional climate features. The paper describes the rationale for the definition of the new regions and analyses their homogeneity. The regions are defined as polygons and are provided as coordinates and a shapefile together with companion R and Python notebooks to illustrate their use in practical problems (e.g. calculating regional averages). We also describe the generation of a new dataset with monthly temperature and precipitation, spatially aggregated in the new regions, currently for CMIP5 and CMIP6, to be extended to other datasets in the future (including observations). The use of these reference regions, dataset and code is illustrated through a worked example using scatter plots to offer guidance on the likely range of future climate change at the scale of the reference regions. The regions, datasets and code (R and Python notebooks) are freely available at the ATLAS GitHub repository: https://github.com/SantanderMetGroup/ATLAS (last access: 24 August 2020), https://doi.org/10.5281/zenodo.3998463 (Iturbide et al., 2020).


2019 ◽  
Vol 116 (21) ◽  
pp. 10418-10423 ◽  
Author(s):  
Orly Razgour ◽  
Brenna Forester ◽  
John B. Taggart ◽  
Michaël Bekaert ◽  
Javier Juste ◽  
...  

Local adaptations can determine the potential of populations to respond to environmental changes, yet adaptive genetic variation is commonly ignored in models forecasting species vulnerability and biogeographical shifts under future climate change. Here we integrate genomic and ecological modeling approaches to identify genetic adaptations associated with climate in two cryptic forest bats. We then incorporate this information directly into forecasts of range changes under future climate change and assessment of population persistence through the spread of climate-adaptive genetic variation (evolutionary rescue potential). Considering climate-adaptive potential reduced range loss projections, suggesting that failure to account for intraspecific variability can result in overestimation of future losses. On the other hand, range overlap between species was projected to increase, indicating that interspecific competition is likely to play an important role in limiting species’ future ranges. We show that although evolutionary rescue is possible, it depends on a population’s adaptive capacity and connectivity. Hence, we stress the importance of incorporating genomic data and landscape connectivity in climate change vulnerability assessments and conservation management.


2020 ◽  
Author(s):  
Wei Yuan ◽  
Shuang-ye Wu ◽  
Shugui Hou

<p>This study aims to establish future vegetation changes in the east and central of northern China (ECNC), an ecologically sensitive region in the transition zonal from humid monsoonal to arid continental climate. The region has experienced significant greening in the past several decades. However, few studies exist on how vegetation will change with future climate change, and great uncertainties exist due to complex, and often spatially non-stationary, relationships between vegetation and climate. In this study, we first used historical NDVI and climate data to model this spatially variable relationship with Geographically Weighted Logit Regression. We found that temperature and precipitation could explain, on average, 43% of NDVI variance, and they could be used to model NDVI fairly well. We then establish future climate change using the output of 11 CMIP6 models for the medium (SSP245) and high (SSP585) emission scenarios for the mid-century (2041-2070) and late-century (2071-2100). The results show that for this region, both temperature and precipitation will increase under both scenarios. By late-century under SSP585, precipitation is projected to increase by 25.12% and temperature is projected to increase 5.87<sup>o</sup>C in ECNC. Finally, we used future climate conditions as input for the regression models to project future vegetation (indicated by NDVI). We found that NDVI will increase under climate change. By mid-century, the average NDVI in ECNC will increase by 0.024 and 0.021 under SSP245 and SSP585. By late-century, it will increase by 0.016 and 0.006 under SSP245 and SSP585 respectively. Although NDVI is projected to increase, the magnitude of increase is likely to diminish with higher emission scenarios, possibly due to the benefit of precipitation increase being gradually encroached by the detrimental effects of temperature increase. Moreover, despite the overall NDVI increase, the area likely to suffer vegetation degradation will also expands, particularly in the western part of ECNC. With higher emissions and later into the century, region with low NDVI is likely to shift and/or expand north-forward. Our results could provide important information on possible vegetation changes, which could help to develop effective management strategies to ensure ecological and economic sustainability in the future.</p>


2018 ◽  
Author(s):  
Luis Miguel Pardo ◽  
Ignacio Garrido ◽  
Paulina Bruning ◽  
Charlotte Carrier ◽  
Rossana Reveco ◽  
...  

Western Antarctic shows one of the fastest responses to climate change on Earth. Glacier meltdown and freshening are perhaps the most conspicuous evidence of anthropogenic impacts, that together with ice scouring can strongly modify benthic communities. The spatial extension of these impacts has been rarely explored in rocky subtidal environments. This study describes changes in benthic communities across glacier and bathymetric gradient in Fildes Bay, Antarctica. Suction samples were taken from four sites at increasing distance from the Collin glacier (0 - 2.5 – 5 - 7 km) and three depths (5 – 10 - 15 m). Macrofaunal diversity increased with depth across all distances from the glacier; these changes were associated with the increase in diversity of amphipods and echinoderms. The lowest and highest species diversity occurred at zero and two km from the glacier, indicating a strong, but localized, glacier effect. Variation in salinity tolerance and the abundance of key habitat forming algae could explain the spatial variation in these communities. This result remarks the importance of facilitation as a structuring force in Antarctic benthic communities. We suggest that the fate of communities in future climate-change scenarios will depend on how habitat-forming species respond to these environmental changes.


2021 ◽  
Vol 21 (4) ◽  
pp. 3059-3071
Author(s):  
Guocheng Wang ◽  
Zhongkui Luo ◽  
Yao Huang ◽  
Wenjuan Sun ◽  
Yurong Wei ◽  
...  

Abstract. Grassland aboveground biomass (AGB) is a critical component of the global carbon cycle and reflects ecosystem productivity. Although it is widely acknowledged that dynamics of grassland biomass is significantly regulated by climate change, in situ evidence at meaningfully large spatiotemporal scales is limited. Here, we combine biomass measurements from six long-term (> 30 years) experiments and data in existing literatures to explore the spatiotemporal changes in AGB in Inner Mongolian temperate grasslands. We show that, on average, annual AGB over the past 4 decades is 2561, 1496 and 835 kg ha−1, respectively, in meadow steppe, typical steppe and desert steppe in Inner Mongolia. The spatiotemporal changes of AGB are regulated by interactions of climatic attributes, edaphic properties, grassland type and livestock. Using a machine-learning-based approach, we map annual AGB (from 1981 to 2100) across the Inner Mongolian grasslands at the spatial resolution of 1 km. We find that on the regional scale, meadow steppe has the highest annual AGB, followed by typical and desert steppe. Future climate change characterized mainly by warming could lead to a general decrease in grassland AGB. Under climate change, on average, compared with the historical AGB (i.e. average of 1981–2019), the AGB at the end of this century (i.e. average of 2080–2100) would decrease by 14 % under Representative Concentration Pathway (RCP) 4.5 and 28 % under RCP8.5. If the carbon dioxide (CO2) enrichment effect on AGB is considered, however, the estimated decreases in future AGB can be reversed due to the growing atmospheric CO2 concentrations under both RCP4.5 and RCP8.5. The projected changes in AGB show large spatial and temporal disparities across different grassland types and RCP scenarios. Our study demonstrates the accuracy of predictions in AGB using a modelling approach driven by several readily obtainable environmental variables and provides new data at a large scale and fine resolution extrapolated from field measurements.


2020 ◽  
Vol 12 (20) ◽  
pp. 8373
Author(s):  
Matilda Cresso ◽  
Nicola Clerici ◽  
Adriana Sanchez ◽  
Fernando Jaramillo

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.


2015 ◽  
Vol 9 (3) ◽  
pp. 1105-1128 ◽  
Author(s):  
J. M. Shea ◽  
W. W. Immerzeel ◽  
P. Wagnon ◽  
C. Vincent ◽  
S. Bajracharya

Abstract. In this study, we apply a glacier mass balance and ice redistribution model to examine the sensitivity of glaciers in the Everest region of Nepal to climate change. High-resolution temperature and precipitation fields derived from gridded station data, and bias-corrected with independent station observations, are used to drive the historical model from 1961 to 2007. The model is calibrated against geodetically derived estimates of net glacier mass change from 1992 to 2008, termini position of four large glaciers at the end of the calibration period, average velocities observed on selected debris-covered glaciers, and total glacierized area. We integrate field-based observations of glacier mass balance and ice thickness with remotely sensed observations of decadal glacier change to validate the model. Between 1961 and 2007, the mean modelled volume change over the Dudh Koshi basin is −6.4 ± 1.5 km3, a decrease of 15.6% from the original estimated ice volume in 1961. Modelled glacier area change between 1961 and 2007 is −101.0 ± 11.4 km2, a decrease of approximately 20% from the initial extent. The modelled glacier sensitivity to future climate change is high. Application of temperature and precipitation anomalies from warm/dry and wet/cold end-members of the CMIP5 RCP4.5 and RCP8.5 ensemble results in sustained mass loss from glaciers in the Everest region through the 21st century.


1992 ◽  
Vol 23 (3) ◽  
pp. 137-154 ◽  
Author(s):  
I. Krasovskaia ◽  
L. Gottschalk

One of the most important consequences of future climate change may be an alteration of the surface hydrological balance, including changes in flow regimes, i.e. seasonal distribution of flow and especially the time of occurrence of high/low flow, which is of vital importance for environmental and economic policies. Classification of flow regimes still has an important role for the analyses of hydrological response to climate change as well as for validating climate models on present climatic and hydrologic data, however, with some modifications in the methodology. In this paper an approach for flow regime classification is developed in this context. Different ways of flow regime classification are discussed. The stability of flow regimes is studied in relation to changes in mean annual temperature and precipitation. The analyses have shown that even rather small changes in these variables can cause changes in river flow regimes. Different patterns of response have been traced for different regions of the Nordic countries.


Author(s):  
Junnosuke Horita ◽  
Yoh Iwasa ◽  
Yuuya Tachiki

AbstractThe enhanced or reduced growth of juvenile masu salmon (Oncorhynchus masou masou) may result from climate changes to their environment and thus impact on the eco-evolutionary dynamics of their life-history choices. Male juveniles with status, i.e., if their body size is larger than a threshold, stay in the stream and become resident males reproducing for multiple years, while those with smaller status, i.e., their body size is below the threshold, migrate to the ocean and return to the stream one year later to reproduce only once. Since juvenile growth is suppressed by the density of resident males, the fraction of resident males may stay in equilibrium or fluctuate wildly over a 2-year period. When the threshold value evolves, the convergence stable strategy may generate either an equilibrium or large fluctuations of male residents. If environmental changes occur faster than the rate of evolutionary adaptation, the eco-evolutionary dynamics exhibit a qualitative shift in the population dynamics. We also investigated the relative assessment models, in which individual life-history choices are made based on the individual’s relative status within the juvenile population. The eco-evolutionary dynamics are very different from the absolute assessment model, demonstrating the importance of understanding the mechanisms of life history choices when predicting the impacts of climate change.


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