Find research datasets worth reusing

opencc-zeroAug 2020View details →

Evaluating multiple historical climate products in ecological models under current and projected temperatures

Gridded historical climate products (GHCPs) are employed with increasing frequency when modeling ecological phenomena across large scales and predicting ecological responses to projected climate changes. Concurrently, there is an increasing acknowledgement of the need to account for uncertainty when employing climate projections from ensembles of global circulation models (GCMs) and emissions scenarios. Despite the growing usage and documented differences among GHCPs, uncertainty characterization has primarily focused on the roles of GCM and emissions scenario choice, while the consequences of using a single GHCP to make predictions over space and time has received relatively less attention. Here we employ average July temperature data from observations and seven GHCPs to model plant canopy cover and tree basal area across central Alaska, U.S.A. We first compare fit and support of models employing raw observed or GHCP temperature values versus those with an elevation adjustment, finding (1) greater support for, and better fit using elevation-adjusted versus raw temperature models and (2) overall similar fits of elevation-adjusted models employing temperature from observations or GHCPs. Focusing on basal area, we next compare predictions generated by elevation-adjusted models employing GHCP data under current conditions and a warming scenario of current temperatures plus 2 °C, finding good agreement among GHCPs though with between-GHCP differences and variation primarily at middle elevations (~ 1,000 m). These differences were amplified under the warming scenario. Finally, using pooled indices of prediction variation and difference across GHCP models, we identify characteristics of areas most likely to exhibit prediction uncertainty under current and warming conditions. Despite (1) overall good performance of GHCP data relative to observations in models and (2) positive correlation among model predictions, variation in predictions across models—particularly in mid-elevation areas where the position of treeline may be changing—suggests researchers should exercise caution if selecting a single GHCP for use in models. We recommend the use of multiple GHCPs to provide additional uncertainty information beyond standard estimated prediction intervals, particularly when model predictions are employed in conservation planning.

opencc-zeroDec 2012View details →

Data from: Historical changes in northeastern US bee pollinators related to shared ecological traits

Pollinators such as bees are essential to the functioning of terrestrial ecosystems. However, despite concerns about a global pollinator crisis, long-term data on the status of bee species are limited. We present a long-term study of relative rates of change for an entire regional bee fauna in the northeastern United States, based on >30,000 museum records representing 438 species. Over a 140-y period, aggregate native species richness weakly decreased, but richness declines were significant only for the genus Bombus. Of 187 native species analyzed individually, only three declined steeply, all of these in the genus Bombus. However, there were large shifts in community composition, as indicated by 56% of species showing significant changes in relative abundance over time. Traits associated with a declining relative abundance include small dietary and phenological breadth and large body size. In addition, species with lower latitudinal range boundaries are increasing in relative abundance, a finding that may represent a response to climate change. We show that despite marked increases in human population density and large changes in anthropogenic land use, aggregate native species richness declines were modest outside of the genus Bombus. At the same time, we find that certain ecological traits are associated with declines in relative abundance. These results should help target conservation efforts focused on maintaining native bee abundance and diversity and therefore the important ecosystems services that they provide.

opencc-zeroDec 2015View details →

Data from: Introgression of mtDNA in Urosaurus lizards: historical and ecological processes

Introgression of mtDNA appears common in animals but the implications of acquiring a novel mitochondrial genome are not well known. This study investigates mito-genome introgression between the lizard species Urosaurus graciosus, a thermal specialist, and U. ornatus, a species that occupies a wider range of thermal environments. As ectotherms, their metabolic rate is strongly influenced by the thermal environment; with mitochondria being linked to metabolic rates, overall energy budgets could be impacted by introgression. I use mitochondrial gene trees, inferred from Bayesian analyses of Cyt-B and ND1 gene sequences, along with morphology and microsatellites from nineteen populations of these two species to address if the direction and location of mito-nuclear discordance match predictions of introgression resulting from past population expansions. MtDNA is expected to move from resident species into expanding or invading species. Second, does having a heterospecific form of mitochondria impact body size, a trait strongly associated with fitness? Multiple independent introgression events of historic origin were detected. All introgression was unidirectional with U. ornatus-type mtDNA found in U. graciosus parental type individuals. This result was consistent with population expansions detected in U. graciosus but not U. ornatus. Females with heterospecific mtDNA were significantly smaller than homospecific forms and heterospecific males had a different relationship of body mass to body length than those with homospecific mtDNA. These changes indicate a potential selective disadvantage for individuals with heterospecific mitochondria and are consistent with the theoretical expectation that deleterious alleles are more likely to persist in expanding populations.

opencc-zeroDec 2014View details →

Data from: The evolution of life cycle complexity in aphids: ecological optimization, or historical constraint?

For decades, biologists have debated why many parasites have obligate multi-host life cycles. Here, we use comparative phylogenetic analyses of aphids to evaluate the roles of ecological optimization and historical constraint in the evolution of life cycle complexity. If life cycle complexity is adaptive, it should be evolutionarily labile, i.e., change in response to selection. We provide evidence that this is true in some aphids (aphidines), but not others (non-aphidines) – groups that differ in the intensity of their relationships with primary hosts. Next, we test specific mechanisms by which life cycle complexity could be adaptive or a constraint. We find that among aphidines there is a strong association between complex life cycles and polyphagy but only a weak correlation between life cycle complexity and reproductive mode. In contrast, among non-aphidines the relationship between life cycle complexity and host breadth is weak but the association between complex life cycles and sexual reproduction is strong. Thus, although the adaptiveness of life cycle complexity appears to be lineage specific, across aphids, life cycle evolution appears to be tightly linked with the evolution of other important natural history traits.

opennotspecifiedMar 2013View details →

Subspecies and Distribution. A. [. fusciceps Gray, 1866 — NW Ecuador, W of the Andes, historically in the provinces of Esmeraldas and Carchi, from the Colombian border S to the Cordillera de Colonche in the Guayas Province (most S record is in "Puente sobre el rio Chimbo," Chimborazo Province), but today it is restricted to two remnant populations (Awa Ethnological Reserve N of the Rio Mira, and Cotacachi-Cayapas Ecological Reserve and adjacent Los Cedros Protected Forest and surrounding forests S of the Rio Mira). A. f. rufiventris Sclater, 1872 — E Panama (Atlantic slope) and W Colombia from the Uraba region in NW Antioquia, N through Cordoba, Sucre, and N Bolivar departments (N distributional limit on the S bank of the Canal del Dique, Cartagena), W of the Rio Cauca to the coast, E to the lower Rio Cauca along the W bank to SC Antioquia (the Cerro Pirre or the Rio Tucuti marks the border with A. geoffroyi grisescens), and S to the Cordillera Occidental of the Andes in SW Colombia (the most southerly record is Barabacoas, Narino Department). in Atelidae

Subspecies and Distribution. A. [. fusciceps Gray, 1866 — NW Ecuador, W of the Andes, historically in the provinces of Esmeraldas and Carchi, from the Colombian border S to the Cordillera de Colonche in the Guayas Province (most S record is in "Puente sobre el rio Chimbo," Chimborazo Province), but today it is restricted to two remnant populations (Awa Ethnological Reserve N of the Rio Mira, and Cotacachi-Cayapas Ecological Reserve and adjacent Los Cedros Protected Forest and surrounding forests S of the Rio Mira). A. f. rufiventris Sclater, 1872 — E Panama (Atlantic slope) and W Colombia from the Uraba region in NW Antioquia, N through Cordoba, Sucre, and N Bolivar departments (N distributional limit on the S bank of the Canal del Dique, Cartagena), W of the Rio Cauca to the coast, E to the lower Rio Cauca along the W bank to SC Antioquia (the Cerro Pirre or the Rio Tucuti marks the border with A. geoffroyi grisescens), and S to the Cordillera Occidental of the Andes in SW Colombia (the most southerly record is Barabacoas, Narino Department).

opencc-zeroMay 2022View details →

Historical connections between Atlantic Forest and Amazonia drove genetic and ecological diversity in Lithobates palmipes (Anura, Ranidae)

The Atlantic and Amazon rainforests have a shared but unclear past, with intermittent connections resulting from historical climate change. We investigate these connections by studying the phylogeography and climatic niche of the disjunct distributed frog Lithobates palmipes. We sequenced two fragments of mitochondrial DNA from Atlantic Forest (AtF) and Amazonia (AmF) individuals and evaluated how genetic diversity is distributed in space and whether past demographic changes occurred. Also, we evaluated the existence of past suitable connections between biomes for L. palmipes through ecological niche models (ENM) and tested for niche divergence. The AtF group is nested within the AmF group and closely related to individuals from eastern Amazonia, a pattern recovered in many species that used northeast connection routes. We found evidence of recurrent use of connections in different directions and time during the Pleistocene, resulting in genetic structure between biomes, with no signal of demographic change and evidence of niche divergence across both genetic groups. ENMs indicated suitable areas connecting forests throughout northeastern Brazil during the Pleistocene. Mitochondrial lineages do not match biomes exactly. One lineage is composed of AtF populations and eastern Amazonia individuals. The other is composed of western Amazonia individuals, suggesting an effect of past climatic heterogeneity within the Amazonia forest. This is the first evidence that this route drove genetic and ecological diversity for amphibians recently, a group with habits and ecological requirements different from other vertebrates that have been shown to use this putative corridor.

Fig. 1 in Is Phylogeographic Congruence Predicted by Historical Habitat Stability, or Ecological Co-associations?

Fig. 1. Ecological niche models (ENMs) estimated for each of the five species from present-day to Last Glacial Maximum, and climatic stability based on the ENM time series. Color coding uses "warm" colors to indicate areas of highest probability of occurrence, or highest climatic stability. Species names are abbreviated as follows: C.p. (Cryptocercus punctulatus), R.f. (Reticulitermes flavipes), O.d. (Odontotaenius disjunctus), S.s. (Scolopocryptops sexspinosus), and N.a. (Narceus americanus).

Fig. 4 in Is Phylogeographic Congruence Predicted by Historical Habitat Stability, or Ecological Co-associations?

Fig. 4. Assessment of phylogeographic structure via comparison of FST (grey bars) versus Φ ST (black bars). All values represent mean differentiation across all pairs of BAPS clusters per species (i.e., "global" values). Species names are abbreviated as in Fig. 1.

Fig. 2 in Is Phylogeographic Congruence Predicted by Historical Habitat Stability, or Ecological Co-associations?

Fig. 2. Unrooted dendrograms representing two competing hypotheses about key drivers of phylogeographic congruence among five saproxylic invertebrates: abiotic factors related to historical climatic stability (left) versus biotic factors related to ecological co-associations (right). Scale bars represent either the inverse of a measure of habitat overlap (1 – Schoener's D; left), or the cumulative dissimilarity score for species interactions based on trophic guild, timing of colonization during succession, frequency of syntopy, and presumed interaction type (right). Numbers on nodes for the biotic drivers scenario indicate the number of jackknife replicates (out of 4) that supported a given predicted partition. Species names are abbreviated as in Fig. 1.

Fig. 3 in Is Phylogeographic Congruence Predicted by Historical Habitat Stability, or Ecological Co-associations?

Fig. 3. The number and distribution of spatial-genetic clusters, and phylogenetic relationships among mitochondrial DNA (mtDNA) haplotypes, for each of the five focal species. BAPS clusters were arbitrarily color-coded (alphabetic names are also shown), and spatial projections were based on membership of georeferenced individuals (Voronoї tessellations not shown). Grey shading identifies the "northern region" of the study area, referred to in the main text. Rooted phylogenetic trees (outgroup not shown) are simplified and color-coded corresponding to BAPS cluster membership of each mtDNA haplotype. Nodes with bootstrap support values>70% are marked by asterisks. Species names are abbreviated as in Fig. 1.

opencc-zeroJul 2021View details →

Is phylogeographic congruence predicted by historical habitat stability, or ecological co-associations?

Comparative phylogeographic studies can uniquely distinguish idiosyncratic versus community-wide responses to past environmental change. However, to date, impacts of species interactions have been largely overlooked. Here we used non-genetic data to characterize two competing scenarios about expected levels of congruence among five saproxylic invertebrate species (i.e., a wood-feeding cockroach, termite and beetle; a predatory centipede, and a detritivorous millipede) from the southern Appalachians mountains—a topographically complex unglaciated landscape. Under one scenario, abiotic factors primarily drove species' responses, with predicted congruence based on spatial overlap of climatically stable habitat areas estimated for each species via ecological niche modeling. The other scenario considered biotic factors to be most influential, with proxies for actual or potential direct interactions used to predict congruence. Analyses of mitochondrial and nuclear DNA sequence datasets for each species focused on four axes of comparison: the number and distribution of spatial-genetic clusters, phylogeographic structure, changes in long-term effective population size, and historical gene flow dynamics. Overall, we found stronger support for ecological co-associations scenario, suggesting an important influence of biotic factors in constraining or facilitating species' responses to Pleistocene climatic cycles. However, there was an imperfect fit between this scenario's predictions and outcomes of empirical data analyses. Thus, our conclusions are compelling, but tentative. This work advances comparative phylogeography by expanding the scope of inferences beyond abiotic drivers, and provides insights into the evolutionary history of a functionally important ecological community, within a globally recognized center of endemism.

publicMar 2013View details →

Data from: Historical changes in northeastern US bee pollinators related to shared ecological traits

Open the record for dataset details and reuse information.

publicNov 2016View details →

Data from: Introgression of mtDNA in Urosaurus lizards: historical and ecological processes

Open the record for dataset details and reuse information.

publicMar 2015View details →

Data from: The evolution of life cycle complexity in aphids: ecological optimization, or historical constraint?

Open the record for dataset details and reuse information.

publicSep 2016View details →

Data from: Ecological and historical determinants of population genetic structure and diversity in the Mediterranean shrub Rosmarinus officinalis (Lamiaceae)

Open the record for dataset details and reuse information.

publicOct 2017View details →

Data from: Influence of historical land use and modern agricultural expansion on the spatial and ecological divergence of sugarcane borer, Diatraea saccharalis (Lepidoptera: Crambidae) in Brazil

Open the record for dataset details and reuse information.

publicAug 2020View details →

Evaluating multiple historical climate products in ecological models under current and projected temperatures

Open the record for dataset details and reuse information.