Using ocean models to predict spatial and temporal variation in marine carbon isotopes

Ecosphere, Journal Year: 2017, Volume and Issue: 8(5)

Published: May 1, 2017

Abstract Natural‐abundance stable isotope ratios provide a wealth of ecological information relating to food web structure, trophic level, and location. The correct interpretation data requires an understanding spatial temporal variation in the isotopic compositions at base web. In marine pelagic environments, accurate is hampered by lack reliable, spatio‐temporally distributed measurements baseline compositions. this study, we present relatively simple, process‐based carbon model that predicts spatio‐temporal distributions composition phytoplankton (here expressed as δ 13 C PLK ) across global ocean one degree monthly resolution. driven output from coupled physics‐biogeochemistry model, NEMO ‐ MEDUSA , operates offline; it could also be alternative underlying systems. Model validation challenged same explicit motivates development, but predictions our successfully reproduce major patterns values observed zooplankton, are consistent with simulations models. represent initial hypothesis baselines areas where few currently available, best available tool estimate basin scales.

Language: Английский

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Incorporating Genetic Diversity to Optimize the Plant Conservation Network in the Third Pole

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(3)

Published: March 1, 2025

Climate change poses a significant threat to the survival of many species. Although protected areas can slow down biodiversity loss, they often lack systematic planning and do not integrate genetic diversity. Genetic diversity is key prerequisite for species ability tolerate new conditions. Using population distribution data from 96 plant in Third Pole (encompassing Tibetan Plateau adjacent mountains), we mapped patterns diversity, projected climate-driven range dynamics future erosion, designed an optimal conservation framework region. We identified several patches high haplotype (HD), with relatively number haplotypes southeastern Pole. Regression models revealed that climate topography have interacted shape latitude precipitation being best predictors HD cpDNA nrDNA, respectively. Ecological niche modeling predicted approximate 43 km northwestward 86 m upward shift suitable habitats under scenarios, likely leading loss up 13.19% 15.49% nrDNA Alarmingly, 71.20% newly priority fall outside existing planned National Park Clusters. Therefore, recommend expanding network by 2.02 × 105 km2 (5.91%) Pole, increasing total conserved area 1.36 106 (39.93%) effectively preserve evolutionary potential plants. This study represents innovative attempt incorporate into efforts.

Language: Английский

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Mapping migration in a songbird using high‐resolution genetic markers

Molecular Ecology, Journal Year: 2014, Volume and Issue: 23(23), P. 5726 - 5739

Published: Oct. 24, 2014

Neotropic migratory birds are declining across the Western Hemisphere, but conservation efforts have been hampered by inability to assess where migrants most limited-the breeding grounds, stopover sites or wintering areas. A major challenge has lack of an efficient, reliable and broadly applicable method for measuring strength connections between populations annual cycle. Here, we show how high-resolution genetic markers can be used identify genetically distinct groups a bird, Wilson's warbler (Cardellina pusilla), at fine enough spatial scales facilitate assessing regional drivers demographic trends. By screening 1626 samples using 96 highly divergent single nucleotide polymorphisms selected from large pool candidates (~450 000), novel region-specific routes timetables migration along Pacific Flyway. Our results illustrate that more reliable, precise amenable high throughput than previously described intrinsic marking techniques, making them large-scale monitoring organisms.

Language: Английский

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assignPOP: An r package for population assignment using genetic, non‐genetic, or integrated data in a machine‐learning framework

Methods in Ecology and Evolution, Journal Year: 2017, Volume and Issue: 9(2), P. 439 - 446

Published: Sept. 18, 2017

Abstract The use of biomarkers (e.g., genetic, microchemical and morphometric characteristics) to discriminate among assign individuals a population can benefit species conservation management by facilitating our ability understand structure demography. Tools that evaluate the reliability large genomic datasets for discrimination assignment, as well allow their integration with non‐genetic markers same purpose, are lacking. Our r package, POP , provides both functions in supervised machine‐learning framework. uses Monte‐Carlo K ‐fold cross‐validation procedures, principal component analysis, estimate assignment accuracy membership probabilities, using training (i.e., baseline source population) test validation) independent. A user then build specified predictive model based on relative sizes these classification functions, including linear discriminant support vector machine, naïve Bayes, decision tree random forest. any researcher who seeks genetic or data infer individuals. is freely available package under GPL license, be downloaded from CRAN at https://github.com/alexkychen/assignPOP . comprehensive tutorial also found https://alexkychen.github.io/assignPOP/

Language: Английский

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Space, time and complexity in plant dispersal ecology

Movement Ecology, Journal Year: 2014, Volume and Issue: 2(1)

Published: Aug. 1, 2014

Dispersal of pollen and seeds are essential functions plant species, with far-reaching demographic, ecological evolutionary consequences. Interest in dispersal has increased concerns about the persistence populations species under global change. We argue here that advances ecology research will be determined by our ability to surmount challenges spatiotemporal scales heterogeneities ecosystem complexity. Based on this framework, we propose a selected set questions, for which suggest some specific objectives methodological approaches. Reviewed topics include multiple vector contributions dispersal, landscape-dependent patterns, long-distance events, variation consequences communities, climate change, anthropogenic landscapes.

Language: Английский

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Geographic assignment with stable isotopes in IsoMAP

Methods in Ecology and Evolution, Journal Year: 2013, Volume and Issue: 5(3), P. 201 - 206

Published: Nov. 29, 2013

Summary Stable isotope ratios of H and O (δ 2 δ 18 O) are intrinsic properties biological geological materials, can be used to constrain the geographic origin movements such materials. One most widespread uses data in ecology is reconstruct animals by comparing chemically inert tissues predictive models (‘isoscapes’) spatial isotopic variation environmental water. Although analysis for isotope‐based assignment subject ongoing research, a basic framework this work has emerged. Here, we introduce document set tools, implemented within IsoMAP (Isoscapes Modelling, Analysis, Prediction; http://isomap.org ) cyber‐GIS system, that support sample applications. We highlight important considerations potential pitfalls associated with use or misuse tools. In addition increasing accessibility analysis, provides several unique capabilities related generation space‐ time‐specific water isoscapes may advance field assignment. Functionality existing toolkit limited scope, although system will actively developed future, it intended complement not supplant more flexible customizable analytical

Language: Английский

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Investigating human geographic origins using dual-isotope (87Sr/86Sr, δ18O) assignment approaches

PLoS ONE, Journal Year: 2017, Volume and Issue: 12(2), P. e0172562 - e0172562

Published: Feb. 21, 2017

Substantial progress in the application of multiple isotope analyses has greatly improved ability to identify nonlocal individuals amongst archaeological populations over past decades. More recently development large scale models spatial isotopic variation (isoscapes) contributed geographic assignments human and animal origins. Persistent challenges remain, however, accurate identification individual origins from skeletal data studies (and animal) migration provenance. In an attempt develop test more standardized quantitative approaches assignment using two methods, combining 87Sr/86Sr δ18O isoscapes, are examined for Circum-Caribbean region: 1) Interval approach a defined range fixed per location; 2) Likelihood univariate bivariate probability density functions. These methods tested with enamel modern sample known origin Caracas, Venezuela further explored samples unknown recovered Cuba Trinidad. The results emphasize both potential limitation different approaches. Validation tests on exclude most areas region correctly highlight Caracas as possible place positive validation clearly demonstrate overall efficacy dual-isotope geoprovenance. accuracy precision may be by better understanding relationships between environmental biological variation; continued refinement relevant isoscapes; eventual incorporation broader array proxy data.

Language: Английский

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Determining origin in a migratory marine vertebrate: a novel method to integrate stable isotopes and satellite tracking

Ecological Applications, Journal Year: 2014, Volume and Issue: 25(2), P. 320 - 335

Published: Sept. 15, 2014

Stable isotope analysis is a useful tool to track animal movements in both terrestrial and marine environments. These intrinsic markers are assimilated through the diet may exhibit spatial gradients as result of biogeochemical processes at base food web. In environment, maps predict distribution stable isotopes limited, thus determining geographic origin has been reliant upon integrating satellite telemetry data. Migratory sea turtles regularly move between foraging reproductive areas. Whereas most nesting populations can be easily accessed monitored, little known about demographic trends populations. The purpose present study was examine migration patterns loggerhead aggregations Gulf Mexico (GoM), where have historically understudied. Two methods assignment using values known-origin samples from were compared: (1) nominal approach discriminant (2) novel continuous-surface bivariate carbon nitrogen isoscapes (isotopic landscapes) developed for this study. Tissue obtained 60 satellite-tracked individuals five beaches within GoM. Both methodological approaches resulted high accuracy area determination, though each advantages disadvantages. more appropriate when defined boundaries necessary, but up 42% could not considered approach. All included approach, individual results aggregated identify hotspots use, rate lower than assignment. validation provides foundation future turtle studies region inexpensively determine large numbers untracked individuals. Regular monitoring with sampling used fill critical data gaps regarding habitat use patterns. Probabilistic previously presented here also applied other migratory species.

Language: Английский

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Evidence of widespread movements from breeding to molting grounds by North American landbirds

Ornithology, Journal Year: 2018, Volume and Issue: 135(3), P. 506 - 520

Published: May 2, 2018

Precise locations for the complete feather molt of North American landbirds, relative to their breeding territories, remain undocumented most species. We analyzed >760,000 records 140 species at 936 bird-capture stations assess probabilities recording both molting landbirds sites and birds sites, investigate latitudinal, longitudinal, elevational shifts from grounds. demonstrate widespread evidence molt-migrations among a variety including many migratory previously thought on "breeding grounds." Geospatial differences between grounds were detected in all 4 compass directions as well upslope downslope elevation, while individuals some appeared disperse specific not discriminated by spatial direction or elevation territories. Although western populations are reported undergo more molt-migration than eastern species, our molt-movement similar America greater east west several Combining results with those these previous studies, we suggest that landbird move longer distances molt, whereas may equally likely shorter habitats, remaining within overall ranges Heterogeneous responses suggested which relate success, resource availability weather events, other factors. Researchers using stable-isotopic, genetic, geolocator techniques need consider potential strategies, incorporate habitat requirements into full-annual-cycle conservation efforts.

Language: Английский

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Large‐scale spatial analysis of ringing and re‐encounter data to infer movement patterns: A review including methodological perspectives

Methods in Ecology and Evolution, Journal Year: 2014, Volume and Issue: 5(12), P. 1337 - 1350

Published: Sept. 3, 2014

Summary A major aim of bird ringing is to provide information about the migration and movements populations. However, in comparison with demographic studies, little research has been devoted improving quantitative inferences through large‐scale spatial analyses. This represents a serious knowledge gap because robust on geographical linkages migratory populations throughout annual cycle necessary understand ecology evolution migrants for conservation management Here, we review recent developments emerging opportunities study based marked birds. Large‐scale analyses data need account spatiotemporal variation re‐encounter probability complexity movement processes, including variability among individuals direction distance. We identify seven studies that used methods gathered by national centres. In most cases, numbers ringed recovered series source destination areas were derive estimates proportion each population travelling area. Where recovery sparse, precision was improved incorporating probabilities similar species. When not available, could sometimes be drawn local recapture from areas. Studies date illustrate these sets can inferences. Further work needed develop modelling approaches test their sensitivity key assumptions using both real simulated data. Data all birds marked, only those re‐encountered, are often inaccessible should computerised parallel analytical developments. Further, there great potential formal combination additional sources such as counts detailed radiotracking or loggers. Because operations cover long periods time exist large quantities, they hold promise inferring patterns, changes relation climate, land use change other environmental drivers.

Language: Английский

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