Ecometric modelling of tooth shape and precipitation gradients among lemurs on Madagascar

2019 ◽  
Author(s):  
Ethan L Fulwood
Keyword(s):  
Environmental Variables ◽  
Annual Precipitation ◽  
Morphological Adaptation ◽  
Fallback Foods ◽  
Phenotypic Characters ◽  
Community Values ◽  
Precipitation Seasonality ◽  
Dirichlet Normal Energy ◽  
Orientation Patch Count ◽  
Desert Zone

Abstract Ecometric modelling relates spatial environmental variables to phenotypic characters to better understand morphological adaptation and help reconstruct past environments. Here, the community means of the dental topography metrics Dirichlet normal energy (DNE) and orientation patch count (OPC) are tested against annual precipitation and precipitation seasonality among lemurs across Madagascar. Dry, seasonal environments are expected to be associated with high DNE and OPC, as lemurs living in these environments are more likely to rely on tougher foods. Ecometric models are also used to calculate ecometric loads for lemur taxa hypothesized to be experiencing evolutionary disequilibria and to reconstruct annual precipitation and precipitation seasonality at the ~500 years BP subfossil cave site of Ankilitelo. DNE was highest in highly seasonal but wet environments. Seasonal exploitation of fallback foods and the availability of new leaves during wet periods may be most important in driving community DNE. OPC was weakly predicted by annual precipitation and seasonality but its distribution appeared to be driven by a stepwise increase in its community values in rainforest environments. The lemur fauna from Ankilitelo appears to resemble communities from moister environments than occur in the spiny desert zone in which the site is situated today.

scholarly journals Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nabaz R. Khwarahm
Keyword(s):  
Climate Change ◽  
Habitat Suitability ◽  
Environmental Variables ◽  
Climate Changes ◽  
Future Climate ◽  
Annual Precipitation ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Kurdistan Region ◽  
Oak Tree

Abstract Background The oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables. Results The model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes. Conclusions The results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

scholarly journals Influence of Earthquakes on Landslide Susceptibility in a Seismic Prone Catchment in Central Asia

2021 ◽  
Vol 11 (9) ◽  
pp. 3768
Author(s):  
Fengqing Li ◽  
Isakbek Torgoev ◽  
Damir Zaredinov ◽  
Marina Li ◽  
Bekhzod Talipov ◽  
...  
Keyword(s):  
Central Asia ◽  
Landslide Susceptibility ◽  
Environmental Variables ◽  
Limit Equilibrium ◽  
Explanatory Power ◽  
Equilibrium Analysis ◽  
Annual Precipitation ◽  
Earthquake Scenario ◽  
Earthquake Scenarios ◽  
Local Decision

Central Asia is one of the most challenged places, prone to suffering from various natural hazards, where seismically triggered landslides have caused severe secondary losses. Research on this problem is especially important in the cross-border Mailuu-Suu catchment in Kyrgyzstan, since it is burdened by radioactive legacy sites and frequently affected by earthquakes and landslides. To identify the landslide-prone areas and to quantify the volume of landslide (VOL), Scoops3D was selected to evaluate the slope stability throughout a digital landscape in the Mailuu-Suu catchment. By performing the limit equilibrium analysis, both of landslide susceptibility index (LSI) and VOL were estimated under five earthquake scenarios. The results show that the upstream areas were more seismically vulnerable than the downstream areas. The susceptibility level rose significantly with the increase in earthquake strength, whereas the VOL was significantly higher under the extreme earthquake scenario than under the other four scenarios. After splitting the environmental variables into sub-classes, the spatial variations of LSI and VOL became more clear: the LSI reduced with the increase in elevation, slope, annual precipitation, and distances to faults, roads, and streams, whereas the highest VOL was observed in the areas with moderate elevations, high precipitation, grasslands, and mosaic vegetation. The relative importance analysis indicated that the explanatory power reduced with the increase in earthquake level and it was significant higher for LSI than for VOL. Among nine environmental variables, the distance to faults, annual precipitation, slope, and elevation were identified as important triggers of landslides. By a simultaneous assessment of both LSI and VOL and the identification of important triggers, the proposed modelling approaches can support local decision-makers and householders to identify landslide-prone areas, further design proper landslide hazard and risk management plans and, consequently, contribute to the resolution of transboundary pollution conflicts.

Ecological Niche Modeling Predicting the Potential Distribution of African Horse Sickness Virus from 2020 - 2060

2021 ◽  
Author(s):  
Ayalew Assefa ◽  
Abebe Tibebu ◽  
Amare Bihon ◽  
Alemu Dagnachew ◽  
Yimer Muktar
Keyword(s):  
Solar Radiation ◽  
Ecological Niche ◽  
Annual Precipitation ◽  
Maximum Temperature ◽  
Mean Annual Precipitation ◽  
African Horse Sickness ◽  
Diurnal Range ◽  
Annual Minimum Temperature ◽  
Precipitation Seasonality ◽  
Vector Borne

Abstract African horse sickness is a vector-borne, non-contagious and highly infectious disease of equines caused by African Horse Sickness viruses (AHSv) that mainly affect horses. The occurrence of the disease causes huge economic impacts because of its fatality rate is high, trade ban and disease control costs. In planning of vectors and vector borne diseases, the application of Ecological niche models (ENM) used an enormous contribution in exactly delineating the suitable habitats of the vector. We developed an ENM with the objective of delineating the global suitability of AHSv outbreaks retrospective based on data records from 2005–2019. The model was developed in R software program using Biomod2 package with an Ensemble modeling technique. Predictive environmental variables like mean diurnal range, mean precipitation of driest month(mm), precipitation seasonality (cv), mean annual maximum temperature (oc), mean annual minimum temperature (oc) mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm) mean annual precipitation (mm), solar radiation (kj /day), elevation/altitude (m), wind speed (m/s) were used to develop the model. From these variables, solar radiation, mean maximum temperature, average annual precipitation, altitude and precipitation seasonality contributed 36.83%, 17.1%, 14.34%, 7.61%, and 6.4%, respectively. The model depicted the sub-Sahara African continent as the most suitable area for the virus. Mainly Senegal, Burkina Faso, Niger, Nigeria, Ethiopia, Sudan, Somalia, South Africa, Zimbabwe, Madagascar and Malawi are African countries identified as highly suitable countries for the virus. Besides, OIE-listed disease-free countries like India, Australia, Brazil, Paraguay and Bolivia have been found suitable for the virusThis model can be used as an epidemiological tool in planning control and surveillance of diseases nationally or internationally.

scholarly journals Development of the first georeferenced map of Rhipicephalus (Boophilus) spp. in Mexico from 1970 to date and prediction of its spatial distribution

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Yazmin Alcala-Canto ◽  
Juan Antonio Figueroa-Castillo ◽  
Froylán Ibarra-Velarde ◽  
Yolanda Vera-Montenegro ◽  
María Eugenia Cervantes-Valencia ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Environmental Variables ◽  
Control Strategies ◽  
Integrated Control ◽  
Area Under The Curve ◽  
Entropy Method ◽  
Distribution Model ◽  
Economic Losses ◽  
Precipitation Seasonality ◽  
Epidemiological Risk

The tick genus Ripicephalus (Boophilus), particularly R. microplus, is one of the most important ectoparasites that affects livestock health and considered an epidemiological risk because it causes significant economic losses due, mainly, to restrictions in the export of infested animals to several countries. Its spatial distribution has been tied to environmental factors, mainly warm temperatures and high relative humidity. In this work, we integrated a dataset consisting of 5843 records of Rhipicephalus spp., in Mexico covering close to 50 years to know which environmental variables mostly influence this ticks’ distribution. Occurrences were georeferenced using the software DIVA-GIS and the potential current distribution was modelled using the maximum entropy method (Maxent). The algorithm generated a map of high predictive capability (Area under the curve = 0.942), providing the various contribution and permutation importance of the tested variables. Precipitation seasonality, particularly in March, and isothermality were found to be the most significant climate variables in determining the probability of spatial distribution of Rhipicephalus spp. in Mexico (15.7%, 36.0% and 11.1%, respectively). Our findings demonstrate that Rhipicephalus has colonized Mexico widely, including areas characterized by different types of climate. We conclude that the Maxent distribution model using Rhipicephalus records and a set of environmental variables can predict the extent of the tick range in this country, information that should support the development of integrated control strategies.

scholarly journals Effect of precipitation seasonality on annual oxygen isotopic composition in the area of spring persistent rain in southeastern China and its paleoclimatic implication

2020 ◽  
Vol 16 (1) ◽  
pp. 211-225 ◽  
Author(s):  
Haiwei Zhang ◽  
Hai Cheng ◽  
Yanjun Cai ◽  
Christoph Spötl ◽  
Ashish Sinha ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Asian Summer Monsoon ◽  
Precipitation Amount ◽  
Annual Precipitation ◽  
Lower Amount ◽  
Seasonal Precipitation ◽  
Precipitation Seasonality ◽  
Precipitation Δ18o

Abstract. This study examines the seasonality of precipitation amount and δ18O over the monsoon region of China (MRC). We found that the precipitation amount associated with the East Asian summer monsoon (EASM) in the spring persistent rain (SPR) region is equivalent to that of the nonsummer monsoon (NSM). The latter contributes ∼50 % to amount-weighted annual δ18O values, in contrast with other areas in the MRC, where the δ18O of annual precipitation is dominated by EASM precipitation. Interannual relationships between the El Niño–Southern Oscillation (ENSO) index, simulated δ18O data from IsoGSM, and seasonal precipitation amount in the SPR region were also examined. We found that on interannual timescales, the seasonality of precipitation amount (EASM ∕ NSM ratio) was modulated by ENSO and primarily influences the variability of amount-weighted annual precipitation δ18O values in the SPR region, although integrated regional convection and moisture source and transport distance may also play subordinate roles. During El Niño (La Niña) phases, less (more) EASM and more (less) NSM precipitation leading to lower (higher) EASM ∕ NSM precipitation amount ratios results in higher (lower) amount-weighted annual precipitation δ18O values and, consequently, in higher (lower) speleothem δ18O values. Characterizing spatial differences in seasonal precipitation is, therefore, key to correctly interpreting speleothem δ18O records from the MRC.

scholarly journals Pollen, vegetation change and climate at Lake Barombi Mbo (Cameroon) during the last ca. 33 000 cal yr BP: a numerical approach

2012 ◽  
Vol 8 (1) ◽  
pp. 59-78 ◽  
Author(s):  
J. Lebamba ◽  
A. Vincens ◽  
J. Maley
Keyword(s):  
Vegetation Change ◽  
Potential Evapotranspiration ◽  
Numerical Approach ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Climate Reconstructions ◽  
Precipitation Seasonality ◽  
Successional Stages ◽  
Artificial Neural ◽  
High Precipitation

Abstract. This paper presents quantitative reconstructions of vegetation and climate along the pollen sequence of Lake Barombi Mbo, southwestern Cameroon (4°39'45.75" N, 9°23'51.63" E, 303 m a.s.l.) during the last 33 000 cal yr BP, improving previous empirical interpretations. The biomisation method was applied to reconstruct potential biomes and forest successional stages. Mean annual precipitation, mean annual potential evapotranspiration and an index of moisture availability were reconstructed using modern analogues and an artificial neural network technique. The results show a dense forested environment around Lake Barombi Mbo of mixed evergreen/semi-deciduous type during the most humid phases (highest precipitation and lowest evapotranspiration), but with a more pronounced semi-deciduous type from ca. 6500 cal yr BP to the present day, related to increased seasonality. This forest displays a mature character until ca. 2800 cal yr BP, then becomes of secondary type during the last millennium, probably due to increased human activity. Two episodes of forest fragmentation are shown, which are synchronous with the lowest reconstructed precipitation and highest potential evapotranspiration values. The first of these occurs during the LGM, and the second one from ca. 3000 to ca. 1200 cal yr BP, mainly linked to high precipitation seasonality. Savanna were, however, never extensive within the Barombi Mbo basin, existing instead inside the forest in form of savanna patches. The climate reconstructions at Lake Barombi Mbo suggest that the artificial neural networks technique would be more reliable in this region, although the annual precipitation values are likely under-estimated through the whole sequence.

Amphibian functional diversity is related to high annual precipitation and low precipitation seasonality in the New World

2019 ◽  
Vol 28 (9) ◽  
pp. 1219-1229 ◽  
Author(s):  
Leticia Margarita Ochoa‐Ochoa ◽  
Nancy R. Mejía‐Domínguez ◽  
Julian A. Velasco ◽  
Katharine Ann Marske ◽  
Carsten Rahbek
Keyword(s):  
Functional Diversity ◽  
New World ◽  
Annual Precipitation ◽  
Precipitation Seasonality ◽  
Low Precipitation

scholarly journals Influence of precipitation seasonality on glacier mass balance and its sensitivity to climate change

2008 ◽  
Vol 48 ◽  
pp. 88-92 ◽  
Author(s):  
Koji Fujita
Keyword(s):  
Mass Balance ◽  
Surface Albedo ◽  
Summer Precipitation ◽  
Arid Environment ◽  
Climatic Conditions ◽  
Snow Accumulation ◽  
Annual Precipitation ◽  
Glacier Mass Balance ◽  
Accumulation Pattern ◽  
Precipitation Seasonality

AbstractNumerical calculations are described, aimed at evaluating the influence of precipitation seasonality (summer and winter) on glacier mass balance. First, equilibrium-line altitudes (ELAs) are modeled using idealized meteorological variables. Modeled climatic conditions (summer mean temperature and annual precipitation) at the ELA of glaciers located within a winter accumulation pattern confirm the observational results of earlier studies. However, the ELA of glaciers located within a summer accumulation climate pattern locates in a colder environment than that of glaciers located within a winter accumulation climate pattern. This difference is mainly due to the annual snow accumulation and the surface albedo. A warming test (+1K) reveals higher sensitivities for the glaciers located within a summer accumulation pattern than for the glaciers located within a winter accumulation pattern. In a humid environment, a significant decrease in snow accumulation on the glaciers located within a summer accumulation pattern directly causes higher sensitivities. In an arid environment, on the other hand, the decreased summer snow induces accelerated melting by lowering the surface albedo and thus increasing absorption of solar radiation on the glaciers located within a summer accumulation pattern. Both influences are due to significant differences in summer precipitation. This study shows the importance of precipitation seasonality on the climatic sensitivity of glacier mass balance, which in previous studies has been linked only with annual precipitation.

scholarly journals The geographical distribution patterns of Chrysoteuchia Hübner in China and description of a new species (Lepidoptera, Crambidae)

ZooKeys ◽  
2019 ◽  
Vol 853 ◽  
pp. 109-118 ◽  
Author(s):  
Lu-Lan Jie ◽  
Jing-Bo Yang ◽  
Wei-Chun Li
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Environmental Variables ◽  
Distribution Patterns ◽  
Annual Precipitation ◽  
Southeastern China ◽  
Present Distribution ◽  
Suitable Area ◽  
First Time ◽  
A New Species

The geographical distribution patterns ofChrysoteuchiaHübner in China are analysed with MaxEnt and ArcGIS based on known localities and nineteen environmental variables. The results suggest that southeastern China is a highly suitable area, and Bio11 (mean temperature of the coldest quarter), Bio12 (annual precipitation) and Bio18 (precipitation of the warmest quarter) are revealed to be the main variables affecting the present distribution patterns. Among them, Bio18 is the strongest predictor with a 24.3% contribution. Furthermore, a new species from Tibet is added to the genus,Chrysoteuchialandryisp. nov., and the male ofC.curvicavusis described for the first time. Images of adults and their genitalia are illustrated, and two maps showing the geographical distribution patterns ofChrysoteuchiain China are provided.

scholarly journals Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 834-844 ◽  
Author(s):  
R. R. Hilário ◽  
J. J. Toledo
Keyword(s):  
Tropical Forests ◽  
Atlantic Forest ◽  
Forest Structure ◽  
Northeastern Brazil ◽  
Annual Precipitation ◽  
Anthropogenic Pressure ◽  
Forest Fragments ◽  
Plant Groups ◽  
Precipitation Seasonality ◽  
Palm Species

Abstract Palms, bromeliads and bamboos are key elements of tropical forests and understanding the effects of climate, anthropogenic pressure and forest structure on these groups is crucial to forecast structural changes in tropical forests. Therefore, we investigated the effects of these factors on the abundance of these groups in 22 Atlantic forest fragments of Northeastern Brazil. Abundance of bromeliads and bamboos were assessed through indexes. Palms were counted within a radius of 20 m. We also obtained measures of vegetation structure, fragment size, annual precipitation, precipitation seasonality and human population density. We tested the effects of these predictors on plant groups using path analysis. Palm abundance was higher in taller forests with larger trees, closed canopy and sparse understory, which may be a result of the presence of seed dispersers and specific attributes of local palm species. Bromeliads were negatively affected by both annual precipitation and precipitation seasonality, what may reflect adaptations of these plants to use water efficiently, but also the need to capture water in a regular basis. Bamboos were not related to any predictor variable. As climate and forest structure affected the abundance of bromeliads and palms, human-induced climatic changes and disturbances in forest structure may modify the abundance of these groups. In addition, soil properties and direct measurements of human disturbance should be used in future studies in order to improve the predictability of models about plant groups in Northeastern Atlantic Forest.

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