Frontiers in Ecology and Evolution

Published by Frontiers Media SA
Online ISSN: 2296-701X
The Oldowan represents the earliest recurrent evidence of human material culture and one of the longest-lasting forms of technology. Its appearance across the African continent amid the Plio-Pleistocene profound ecological transformations, and posterior dispersal throughout the Old World is at the foundation of hominin technological dependence. However, uncertainties exist concerning the degree to which the Oldowan constitutes an environment-driven behavioral adaptation. Moreover, it is necessary to understand how Oldowan technology varied through time in response to hominin ecological demands. In this study, we present the stone tool assemblage from Ewass Oldupa, a recently discovered archeological site that signals the earliest hominin occupation of Oldupai Gorge (formerly Olduvai) ∼2.03 Ma. At Ewass Oldupa, hominins underwent marked environmental shifts over the course of a ∼200 kyr period. In this article, we deployed an analysis that combines technological and typological descriptions with an innovative quantitative approach, the Volumetric Reconstruction Method. Our results indicate that hominins overcame major ecological challenges while relying on technological strategies that remained essentially unchanged. This highlights the Oldowan efficiency, as its basic set of technological traits was able to sustain hominins throughout multiple environments.
| Predictive performance of species distribution models with different algorithms as measured with AUC versus distance of extrapolation in environmental space in a novel geographic region. Distance was measured by first normalizing the distance along each variable axis, then calculating Euclidean distance, and finally dividing by the square root of the number of dimensions (i.e., 19) to obtain a normalized distance in standard-deviation units.
Predictions from species distribution models (SDMs) are commonly used in support of environmental decision-making to explore potential impacts of climate change on biodiversity. However, because future climates are likely to differ from current climates, there has been ongoing interest in understanding the ability of SDMs to predict species responses under novel conditions (i.e., model transferability). Here, we explore the spatial and environmental limits to extrapolation in SDMs using forest inventory data from 11 model algorithms for 108 tree species across the western United States. Algorithms performed well in predicting occurrence for plots that occurred in the same geographic region in which they were fitted. However, a substantial portion of models performed worse than random when predicting for geographic regions in which algorithms were not fitted. Our results suggest that for transfers in geographic space, no specific algorithm was better than another as there were no significant differences in predictive performance across algorithms. There were significant differences in predictive performance for algorithms transferred in environmental space with GAM performing best. However, the predictive performance of GAM declined steeply with increasing extrapolation in environmental space relative to other algorithms. The results of this study suggest that SDMs may be limited in their ability to predict species ranges beyond the environmental data used for model fitting. When predicting climate-driven range shifts, extrapolation may also not reflect important biotic and abiotic drivers of species ranges, and thus further misrepresent the realized shift in range. Future studies investigating transferability of process based SDMs or relationships between geodiversity and biodiversity may hold promise.
Climate change is having profound effects on natural and socio-economic systems, especially via extreme climate events. Using panel data from 129 prefectural-level cities in China from 2013 to 2019, this paper explores the effects of extreme climate on crime rates based on a climate index and manual collection of crime data. The results showed that extreme climate has a significant positive effect on crime rates, increasing by 0.035% for every 1% increase in the extreme climate index. This occurs through two mechanistic pathways: reduced agricultural output and lower employment income. The heterogeneity analysis shows that extreme climate has a greater impact on crime rates in eastern areas which are economically developed and have high levels of immigration. This study provides new perspectives on the impact of extreme climate on the economy and society, in which governments can actively participate in climate governance through environmental protection, energy conservation and emission reduction, and technological innovation to reduce crime rates by reducing the occurrence of extreme climate.
| Satellite image of the study area obtained from Google Earth showing the location of the sites discussed in the main text. 
| Age models of the sites discussed in this study constructed with the Bacon package for R. The probability distribution of the individual calibrated radiocarbon dates are shown in blue. The 95% confidence of the age model is shown in gray, the median probability age of the age model is shown with a red line. 
| Percentage variation of selected taxa in the sites discussed in this study (fine gray lines) and weighted running means of individual taxa (solid colored lines). The dashed vertical rectangles highlight two conspicuous warm-dry intervals discussed in the Lago Cipreses record. 
| Comparison of the Nothofagus and Rumex percentages from Lago Cipreses, Lago Guanaco, Vega Ñandú, and Río Rubens, along with their corresponding macroscopic charcoal records and results of CharAnalysis. The black line corresponds to CHAR, the blue line denotes the calculated background, and the red line a locally defined threshold value. The red filling denotes frequency values above the mean in each site, the + symbol represents statistically significant charcoal peaks, the histogram indicates the magnitude of the statistically significant charcoal peaks. Also shown is the charcoal synthesis curve from southern South America normalized to the modern (1-0.1 ka interval) values. 
The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S). We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.
| Study area, study site and sampling design. (A) Volcano Antisana in the Ecuadorian Andes (extracted from Google map) and location of glacier 15-alpha within the Antisana ice-cap. (B) Map of the 15-alpha glacier between 1997 and 2008. Datum: WGMS 84; unit: UTM. (C) Sampling design: black areas represent the three lateral moraines of years 2001, 2003, and 2005, respectively; these areas were removed the species-area analyses because providing undesirable heterogeneity in the topography and granulometry. (D) Distribution of plots (1 m 2 ).
| PCA biplot combining diversity variables with microclimatic variables and the distance from the glacier on 120 plots. Each plot represented with a symbol assigned to one glacial retreat strip. Larger symbols represent the mean location of plots in each strip.
| Species-area curves at each glacial retreat strip along the chronosequence. Z values (see Preston equation in the section Methods) displayed for each strip. Symbols represent mean values ± SD based on 100 random simulations.
| Frequency of plant individuals developing under the shelter of abiotic refuges (nurse rocks) or heterospecific plants (nurse plants) at the community level, along the chronosequence. Mean values and Error bars: 95% CI are showed for each glacial retreat strip; different letters between strips indicate significant variations (post-hoc Tukey tests). The significance and the sign of the two trends were tested with logistic regressions: ***significant at P < 0.001.
Rapid warming is a major threat for the alpine biodiversity but, at the same time, accelerated glacial retreat constitutes an opportunity for taxa and communities to escape range contraction or extinction. We explored the first steps of plant primary succession after accelerated glacial retreat under the assumption that the first few years are critical for the success of plant establishment. To this end, we examined plant succession along a very short post-glacial chronosequence in the tropical Andes of Ecuador (2–13 years after glacial retreat). We recorded the location of all plant individuals within an area of 4,200 m2 divided into plots of 1 m2. This sampling made it possible to measure the responses of the microenvironment, plant diversity and plants traits to time since the glacial retreat. It also made it possible to produce species-area curves and to estimate positive interactions between species. Decreases in soil temperature, soil moisture, and soil macronutrients revealed increasing abiotic stress for plants between two and 13 years after glacial retreat. This increasing stress seemingly explained the lack of positive correlation between plant diversity and time since the glacial retreat. It might explain the decreasing performance of plants at both the population (lower plant height) and the community levels (lower species richness and lower accumulation of species per area). Meanwhile, infrequent spatial associations among plants indicated a facilitation deficit and animal-dispersed plants were almost absent. Although the presence of 21 species on such a small sampled area seven years after glacial retreat could look like a colonization success in the first place, the increasing abiotic stress may partly erase this success, reducing species richness to 13 species after 13 years and increasing the frequency of patches without vegetation. This fine-grain distribution study sheds new light on nature's responses to the effects of climate change in cold biomes, suggesting that faster glacial retreat would not necessarily result in accelerated plant colonization. Results are exploratory and require site replications for generalization.
(A) 13 C and (B) δ 15 N values measured in charred barley grains from eastern Tianshan complexity (ETC) sites. Dashed lines represent the threshold of "Optimal Water Status" (OWT) and "Superfluous Water Status" (SWT) for barley (Wallace et al., 2013; Vaiglova et al., 2020), and the estimated δ 15 N baseline of local vegetation using average δ 15 N values of archaeological herbivores (Ling et al., 2016).
(A) 13 C and (B) δ 15 N values of archaeological barley recovered from Shirenzigou IV of Phase I and Shirenzigou III of Phase II; (C) proportion of barley, arable weeds (excluding water-demanding weeds) and water-demanding weeds in the archaeobotanical assemblages of Shirenzigou IV (Phase I) and Shirenzigou III (Phase II).
(A) The typical landscapes of Bronze Age lakeside sites (the excavation area of Haiziyan in 2017) and (B) piedmont sites (the piedmont landscape of Shirenzigou) in the eastern Tianshan region; (C) 13 C and (D) δ 15 N values of archaeological barley from lakeside (Haiziyan, Yanchigucheng) and piedmont sites (Shirenzigou IV, Hongshankou, Kuola); (E) proportion of barley, arable weeds (excluding water-demanding weeds) and water-demanding weeds uncovered from lakeside and piedmont sites.
The locations of Shirenzigou IV (SRZ IV, 2,140 m.a.s.l.), Shirenzigou III (SRZ III, 2,200 m.a.s.l.), Haiziyan (HZY, 1,600 m.a.s.l.), Yanchigucheng (YCGC, 2,020 m.a.s.l.), Kuola (KL, 2,200 m.a.s.l.) and Hongshankou (HSK, 2,200 m.a.s.l.) in the eastern Tianshan region. The lowest and highest elevations of Barkol are at Lake Barkol (1,581 m.a.s.l.) and Yueyashan (4,308 m.a.s.l.), respectively. The lowest and highest elevations of Yiwu are at Lake Tuolekule (1,890 m.a.s.l.) and Tuomuerti (4,886 m.a.s.l.), respectively. Maps were generated using ArcMap v. 10.2 with data credit to National Park Service Natural Earth physical map (public domain).
This study combines plant stable isotope and archaeobotanical analyses to explore how ancient pastoral communities in varying landscapes of eastern Tianshan managed their barley fields. The question is less archaeologically investigated, as recent discussions have focused on pastoral and nomadic activities. Results show that diversified cultivation strategies were employed in barley cultivation at different locations in eastern Tianshan. We also observed a diachronic transition toward less labour-intensive crop management corresponding to a growing pastoral lifeway from the late Bronze Age (1300–800 BCE) to historical periods (400 BCE–300 CE). These results inform us about the mechanism by which southwest Asian originated domesticates were adapted to the Inner Asian environments in the context of the early food globalisation.
Mangroves are a highly threatened ecosystem due to climate change and human activity, which increases coastal vulnerability. Knowledge about the ecological dynamics of mangroves on a centennial timescale can reveal the different responses in vegetation, which is useful for implementing basic actions for mangrove restoration, conservation and management. A mangrove ecosystem in the Cuyutlán Lagoon area along the Pacific coast of west-central Mexico is significantly altered as a result of industrialization, salt extraction, and road construction. The long-term dynamics of the mangrove ecosystem has also been controlled by Holocene climatic variability. This study reconstructs the environmental history of mangrove vegetation around the Cuyutlán Lagoon during the last ~1300 years in response to periods of human activity and climate change. The reconstruction was performed using paleoecological techniques in sediment cores that include the use of fossil pollen as a proxy for vegetation and magnetic susceptibility and geochemical data (determined by loss-on-ignition and X-ray fluorescence) as a proxy for past environmental changes. The chronology was determined using 14C dating and the age-depth model was constructed by linear interpolation. Redundancy analysis and non-metric multidimensional scaling (NMDS) were used to discern patterns of distribution of the different proxies. Results revealed that the mangrove pollen assemblage of the Cuyutlán Lagoon was dominated by the arboreal taxa Rhizophora mangle, Euphorbiaceae, Moraceae, and Pinaceae, herbaceous taxa like Poaceae, Chenopodiaceae/Amaranthaceae, and aquatics such as Typhaceae and Cyperaceae. NMDS showed a clear separation between two events of human activity—the Spanish Occupation of Colima (~AD 1523-1524) and the opening of the Manzanillo port (~AD 1824-1825). Climate change events such as the Medieval Climate Anomaly (MCA) (~AD 800-1200) and the Little Ice Age (LIA) (~AD 1350-1850) were also successfully identified. The main responses were mangrove expansion (driven by R. mangle) during the LIA and the Manzanillo Port Opening, while the MCA was a highly perturbed period marked by multiple hurricane events and low or no pollen deposition in the sediment. During the Spanish Occupation, the aquatic taxa Typhaceae expanded together with an increase in Ca, Sr and carbonate contents.
Introduction Among long-distance migratory insects, the monarch butterfly ( Danaus plexippus ) is one of the most iconic, whose journey is fueled by nectar from flowering plants along the migratory route which may involve up to 3,500 km. Understanding how and where monarchs obtain their dietary resources to fuel migratory flight and ensure overwintering stores would provide new insights into the migratory strategy of this species and subsequently help focus conservation efforts. Methods This pilot study was designed as a first attempt to assess the composition, dynamics, and isotopic (δ ² H, δ ¹³ C) composition of essential and non-essential fatty acids (FA) acquired or manufactured de novo from larval host milkweed ( Asclepias spp.) by monarch butterflies and from adult emergence to overwintering. Results Data from controlled laboratory isotopic tracer tests suggested that adult monarchs convert their dietary energy mainly into 16:0 and 18:1 fatty acids and store them as neutral lipids in their abdomen. FA isotopic composition reflects not only dietary sources but also subsequent isotopic fractionation from metabolism. On the other hand, δ ² H values of essential omega-3 fatty acid alpha-linolenic acid (ALA) correlated with δ ² H Wing , as markers of an individual’s geographic origin and indicated the importance of larval diet. Additionally, in wild-type females, high isotopic fractionation in δ ¹³ C ALA between neutral and polar lipids might indicate increased bioconversion activity during gravidity. Finally, δ ² H LIN showed positive H isotope fractionation from larval dietary sources, indicating that catabolic processes were involved in their manufacture. Furthermore, δ ² H LIN showed a negative correlation with δ ² H Wing values, which could potentially be useful when investigating individual life-history traits, such as migratory catabolic efforts or periods of fasting. Discussion This interpretation was supported by significant larger variations in δ ² H LIN and δ ² H LIN overwintering monarchs compared to other FA. Altogether, our results provide the first evidence that the H isotopic analysis of individual fatty acids in migrating and overwintering monarchs can be used to infer the nutritional history of individuals including the provenance of nectaring sites used to fuel key life history events.
Location map of the selected fossil pollen sites (black dots) and the ecoregion units (colored areas) from the boreal forest taiga biome (adapted from Girardin et al., 2009).
Diversity indices averaged for each ecoregion using 1-ka temporal windows; the site number is indicated in parentheses following ecoregion name labels. (A) α diversity from Shannon entropy number equivalent measurement, (B) β diversity, (C) the temporal (βSORt) diversity based on multisite Sørensen dissimilarity, (D) γ ecoregional total diversity; vertical bars represent the one standard deviation range for calculated indices.
Box plots of diversity indices for the North American boreal forest taiga biome derived from transformed indices. The indices are: (A) α diversity, (B) β diversity (C) γ diversity, (D) βSOR spatial diversity, (E) βSIM spatial turnover component, (F) βNES spatial nestedness component, (G) βSORt temporal diversity, (H) βSIMt temporal turnover component, (I) βNESt temporal nestedness component. Letters indicates significant differences between 1-ka time periods at the 5% confidence level obtained from the Least Significant Difference post-hoc tests. Linear regressions (black line) and associated Spearman correlation p-values are also indicated.
Assessment of biodiversity in a changing world is a key issue and studies on the processes and factors influencing its history at relevant time scales are needed. In this study, we analyzed temporal trends of plant diversity using fossil pollen records from the North American boreal forest-taiga biome (NABT). We selected 205 pollen records spanning the last 15,500 years. Diversity was decomposed into α and γ richness, and β diversity, using Shannon entropy indices. We investigated temporal and spatial patterns of β diversity by decomposing it into independent turnover (variation in taxonomic composition due to species replacements) and nestedness (variation due to species loss) components. The palynological diversity of the NABT biome experienced major rearrangements during the Lateglacial and early Holocene in response to major climatic shifts. The β nestedness likely reflected plant immigration processes and generally peaked before the β turnover value, which mirrors spatial and temporal community sorting related to environmental conditions and specific habitat constraints. Palynological diversity was generally maximal during the Lateglacial and the early Holocene and decreased progressively during the Holocene. These results are discussed according to macro-ecological processes, such as immigration, disturbances, and environmental fluctuations, with climate most notably as the main ecological driver at millennial scales.
Interactions between organisms and their environments are central to how biological diversity arises and how natural populations and ecosystems respond to environmental change. These interactions involve processes by which phenotypes are affected by or respond to external conditions (e.g., via phenotypic plasticity or natural selection) as well as processes by which organisms reciprocally interact with the environment (e.g., via eco-evolutionary feedbacks). Organism-environment interactions can be highly dynamic and operate on different hierarchical levels, from genes and phenotypes to populations, communities, and ecosystems. Therefore, the study of organism-environment interactions requires integrative approaches and model systems that are suitable for studies across different hierarchical levels. Here, we introduce the freshwater isopod Asellus aquaticus , a keystone species and an emerging invertebrate model system, as a prime candidate to address fundamental questions in ecology and evolution, and the interfaces therein. We review relevant fields of research that have used A. aquaticus and draft a set of specific scientific questions that can be answered using this species. Specifically, we propose that studies on A. aquaticus can help understanding (i) the influence of host-microbiome interactions on organismal and ecosystem function, (ii) the relevance of biotic interactions in ecosystem processes, and (iii) how ecological conditions and evolutionary forces facilitate phenotypic diversification.
The loggerhead sea turtle is considered a keystone species with a major ecological role in Mediterranean marine environment. As is the case with other wild reptiles, their outer microbiome is rarely studied. Although there are several studies on sea turtle’s macro-epibionts and endo-microbiota, there has been little research on epibiotic microbiota associated with turtle skin and carapace. Therefore we aimed to provide the identification of combined epibiotic eukaryotic, bacterial and archaeal microbiota on Mediterranean loggerhead sea turtles. In this study, we sampled skins and carapaces of 26 loggerheads from the Mediterranean Sea during 2018 and 2019. To investigate the overall microbial diversity and composition, amplicon sequencing of 16S and 18S rRNA genes was performed. We found that the Mediterranean loggerhead sea turtle epibiotic microbiota is a reservoir of a vast variety of microbial species. Microbial communities mostly varied by different locations and seas, while within bacterial communities’ significant difference was observed between sampled body sites (carapace vs. skin). In terms of relative abundance, Proteobacteria and Bacteroidota were the most represented phyla within prokaryotes, while Alveolata and Stramenopiles thrived among eukaryotes. This study, besides providing a first survey of microbial eukaryotes on loggerheads via metabarcoding, identifies fine differences within both bacterial and eukaryotic microbial communities that seem to reflect the host anatomy and habitat. Multi-domain epi-microbiome surveys provide additional layers of information that are complementary with previous morphological studies and enable better understanding of the biology and ecology of these vulnerable marine reptiles.
| Sampling sites of alpine grasslands on the Tibetan Plateau.
| Species importance point map according to the importance of the top 30 soil bacteria at the genus level of alpine grasslands on the Tibetan Plateau.
| Non-metric multidimensional scaling (NMDS) analysis of the soil bacteria in alpine grasslands on the Tibetan Plateau. Different shaped dots represent the samples from different alpine grassland types, and the bumps of the samples bound the faces of different colors. AD, alpine desert; ADS, alpine desert steppe; AM, alpine meadow; AMS, alpine meadow steppe; AS, alpine steppe.
Alpha diversity indices of soil bacterial communities (mean ± SE) in alpine grasslands on the Tibetan Plateau.
Analysis of similarities (ANOSIM) of soil bacteria in alpine grasslands on the Tibetan Plateau.
The Tibetan Plateau, widely known as the world’s “Third Pole,” has gained extensive attention due to its susceptibility to climate change. Alpine grasslands are the dominant ecosystem on the Tibetan Plateau, albeit little is known about the microbial community and diversity among different alpine grassland types. Here, soil bacterial composition and diversity in the upper soils of five alpine grassland ecosystems, alpine meadow (AM), alpine steppe (AS), alpine meadow steppe (AMS), alpine desert (AD), and alpine desert steppe (ADS), were investigated based on the 16S rRNA gene sequencing technology. Actinobacteria (46.12%) and Proteobacteria (29.67%) were the two dominant soil bacteria at the phylum level in alpine grasslands. There were significant differences in the relative abundance at the genus level among the five different grassland types, especially for the Rubrobacter, Solirubrobacter, Pseudonocardia, Gaiella, Haliangium, and Geodermatophilus. Six alpha diversity indices were calculated based on the operational taxonomic units (OTUs), including Good’s coverage index, phylogenetic diversity (PD) whole tree index, Chao1 index, observed species index, Shannon index, and Simpson index. The Good’s coverage index value was around 0.97 for all the grassland types in the study area, meaning the soil bacteria samplings sequenced sufficiently. No statistically significant difference was shown in other diversity indices’ value, indicating the similar richness and evenness of soil bacteria in these alpine grasslands. The beta diversity, represented by Bray–Curtis dissimilarity and the non-metric multidimensional scaling (NMDS), showed that OTUs were clustered within alpine grasslands, indicating a clear separation of soil bacterial communities. In addition, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), pH, and soil water content (SWC) were closely related to the variations in soil bacterial compositions. These results indicated that soil bacterial taxonomic compositions were similar, while soil bacterial community structures were different among the five alpine grassland types. The environmental conditions, including SOM, TN, TP, pH, and SWC, might influence the soil bacterial communities on the Tibetan Plateau.
Cycling of carbon (C), nitrogen (N), calcium (Ca), phosphorus (P), and sulfur (S) is an important ecosystem service that forest soils provide. Humans influence these biogeochemical processes through the deposition of atmospheric pollutants and site disturbances. One way to study these potential anthropogenic trajectories is through long-term monitoring in association with human-caused environmental gradients such as urban-rural gradients. The objective of this study was to characterize changes in surface soil chemistry of urban, suburban and rural forest patches in the Baltimore Metropolitan area. Soil composite samples (0–10 cm) were analyzed for macro- and micronutrients, pH, and C. A total of 12 sites in forest patches dominated by white oak ( Quercus alba ) and tulip poplar ( Liriodendron tulipifera ) were established in 2001, and resampled in 2018. We hypothesized that after almost two decades (1) concentrations of N, Ca, and P, as well as soil pH would be higher, especially in urban forest patches due to local deposition; (2) S levels would be lower due to decreased regional atmospheric deposition and; (3) total soil C would increase overall, but the rate of increase would be higher in the urban end of the gradient due to increased NPP. Overall, means of Ca concentration, pH, and C:N ratios significantly changed from 2001 to 2018. Calcium increased by 35% from 622 to 844 mg kg –1 , pH increased from 4.1 to 4.5, and C:N ratios decreased from 17.8 to 16.7. Along the gradient, Ca, N, P, and S were statistically significant with Ca concentration higher in the urban sites; S and N higher in the suburban sites; and P lower in the urban sites. Confounding factors, such as different geologic parent material may have affected these results. However, despite the unique site conditions, patterns of surface soil chemistry in space and time implies that local and regional factors jointly affect soil development in these forest patches. The increase in pH and Ca is especially notable because other long-term studies demonstrated changes in the opposite direction.
Physical locations (A), genetic diversities (B), and forensic efficiency evaluations (C) of 17 X-chromosomal Multi-InDels in Beijing Han (CHB) and Southern Han (CHS) populations. For genetic diversities, different colors represented different expected heterozygosity (He) values: red and blue denote small and large He values, respectively; the size of shape is proportional to the number of alleles observed in each locus.
Population genetic analyses of different continental populations based on selected 17 loci. (A) Pairwise F ST distances of different continental populations. Different colors represented different F ST values: red denoted small F ST values; blue denoted large F ST values. (B) Multi-dimensional analysis of different continental populations. (C) The phylogenetic tree of different continental populations.
General information of 17 selected Multi-InDel loci on the X chromosome.
Multi-InDel, as the novel genetic markers, showed great potential in forensic research. Whereas, most scholars mainly focused on autosomal Multi-InDels, which might provide limited genetic information in some complex kinship cases. In this study, we selected 17 Multi-InDels on the X chromosome and developed a multiplex amplification panel based on the next-generation sequencing (NGS) technology. Genetic distributions of these 17 loci in Beijing Han, Chinese Southern Han, and the studied Guizhou Han populations revealed that most loci showed relatively high forensic application values in these Han populations. In addition, more allelic variations of some loci were observed in the Guizhou Han than those in Beijing Han and Southern Han populations. Pairwise F ST values, multi-dimensional analysis, and phylogenetic tree of different continental populations showed that selected 17 loci generally could differentiate African, European, East Asian, and South Asian populations. To sum up, the developed panel in this study is not only viewed as the high-efficient supplementary tool for forensic individual identification and paternity analysis, but it is also beneficial for inferring biogeographical origins of different continental populations.
Location of Wombat Pool and other cites mentioned in the text. (A) Regional map; (B) map of Cradle Mountain-Lake St Clair National Park; (C) satellite image of site and surrounding area. Circle = lake or marine sediment record, triangle = archeological site, square = speleothem record, star = Wombat Pool, black line = Cradle Mountain-Lake St Clair National Park boundary, white x = coring location.
| Radiocarbon dating results.
Lithology. Lithology, radiocarbon dates, magnetic susceptibility, and density for the Wombat Pool cores. The asterisk indicates the date that was not used in the chronology.
Age-depth model. Age-depth model for Wombat Pool (black line). The 95% confidence intervals are shown as gray shading. The distributions of the calibrated radiocarbon ages that were used to develop the model are shown in blue, and the date that was not included in the model is indicated in red.
Pollen diagram for percentage of selected taxa from Wombat Pool. Note differing scales on x-axes. Stippled gray shading indicates 10x exaggeration (i.e., Bauera rubioides and Melaleuca), solid gray shading indicates 5x exaggeration, and white shading indication 2x exaggeration. Isoetes values were divided by 50 to aid readability.
On centennial to millennial timescales fire regimes are driven by climate changes, vegetation composition and human activities. We reconstructed the postglacial vegetation and fire history based on pollen and charcoal data from a small lake in Cradle Mountain National Park and investigated the influence that climate, people, and vegetation had on past fire regimes. In the late-glacial period, a slowly warming climate led to a shift in vegetation from coniferous alpine shrubland to Phyllocladus woodland. During this period, fire activity was very low. The initial increase in fires occurred between 12,500–11,000 cal yr BP and led to a decline in forest taxa, a resurgence of grasses and a rise in the pyrophytic buttongrass Gymnoschoenus. The highest fire activity in the record occurred between 10,900–9400 cal yr BP, the warmest interval of the postglacial period based on independent proxy records. Subalpine trees had depressed levels of pollen during this time. After 9000 cal yr BP, fire activity declined substantially, and fire-sensitive rainforest reached its maximum extent ca. 8500–6500 cal yr BP. A major fire perturbation occurred ca. 3,600 cal yr BP, and thereafter rainforest shifted to open Eucalyptus woodland. The comparison of reconstructed fire and vegetation history at Wombat Pool to climate records and archeological data indicated that climate was the primary driver of the observed changes. In the late glacial and early Holocene, climate warming and individual species dispersal traits likely drove changes in vegetation composition that in turn impacted the fire regime. A relatively wet mid-Holocene climate favored rainforest trees whereas the drier and more variable climate of the late Holocene contributed to a decline in rainforest and a shift toward mixed forest as wet sclerophyll elements increased. Archeological evidence suggests humans reoccupied the region ca. 4000 cal yr BP. This may have added an ignition source that was absent in the previous ca. 7000 years and may have contributed to the large fire event ca. 3600 cal yr BP. Although pre-European populations may have been a source of ignition locally, the reconstructed fire history trends from Cradle Mountain National Park match well with large-scale changes in climate patterns.
Southern Central Asia witnessed widespread expansion in urbanism and exchange, between roughly 2200 and 1500 B.C., fostering a new cultural florescence, sometimes referred to as the Greater Khorasan Civilization. Decades of detailed archeological investigation have focused on the development of urban settlements, political systems, and inter-regional exchange within and across the broader region, but little is known about the agricultural systems that supported these cultural changes. In this paper, we present the archaeobotanical results of material recovered from Togolok 1, a proto-urban settlement along the Murghab River alluvial fan located in southeastern Turkmenistan. This macrobotanical assemblage dates to the late 3rd - early 2nd millennia B.C., a time associated with important cultural transformations in southern Central Asia. We demonstrate that people at the site were cultivating and consuming a diverse range of crops including, barley, wheat, legumes, grapes, and possibly plums and apples or pears. This, together with the associated material culture and zooarchaeological evidence, suggest a regionally adapted mixed agropastoral economy. The findings at Togolok 1 contribute to the ongoing discussion of dietary choices, human/landscape interactions, and the adaptation of crops to diverse ecosystems in prehistoric Central Asia.
Climate change was already shown to increase species numbers in high elevations. In contrast, grazing might interfere with climate change effects. To disentangle both the effects remains a major challenge of alpine ecology. The present study investigated both the effects on species diversity along an elevation gradient in the Austrian Central Alps. We aimed to answer the following questions: How do species diversity and frequency of subalpine–alpine–subnival plant communities change in grazed sites with time? Do competitive plant species increase in the communities? How does grazing exclusion affect species diversity, functional groups, and strategy types? Are environmental changes (temperature, sunshine duration, precipitation) responsible for diversity changes or does grazing override climate effects? The study was carried out for 18 years along an elevation gradient from 1,958 to 2,778 m a.s.l. at Obergurgl (Tyrol, Austria), including six different plant communities. A total of 11 grazing exclusions were established. At each community, the frequency of the species was counted in 1 m2 plots yearly or at least every 3–4 years. Environmental data were obtained from the weather station Obergurgl. Changes of the community parameters and the species composition were analyzed by partial redundancy analyses and mixed-effect models. Species diversity increased with time at all grazed sites, but this increase was suppressed under grazing exclusion. Grazing exclusion effects became pronounced after 5 years. The most consistent result was the increase of bryophytes throughout. At the subalpine grassland, tall-growing species expanded in the exclosures; at the upper alpine Carex curvula grassland, snow bed species decreased with grazing exclusion. Among the environmental factors, sunshine duration of the previous year’s autumn quartal was found to be the essential variable for the changes. We concluded that diversity increases in grazed communities of the Austrian Central Alps can be attributed to climate change. An indication of slightly reduced and altered weather effects under grazing exclusion was found.
| Global molecular phylogeny of trap-jaw ants reconstructed under Bayesian inference used to ancestral chromosome reconstruction. Clades A-G are highlighted in different colors. Morphological groups proposed by Brown (1978), are shown at the right side of the tree. The outgroup can be found at the top of the figure in light purple.
| Ancestral haploid chromosome state reconstruction inferred under Bayesian Inference and Maximum Likelihood methods. The ancestral chromosome number with the highest probability or with the best likelihood are denoted at the main nodes. The colors of branches represent each given chromosome number according to the legend. The known karyotypes of species are given at the tip. An ideogram was estimated from the available karyotypic formulae (in bold), denoting the number of metacentric, submetacentric, subtelocentric, and telocentric chromosomes along the phylogeny.
| Chromosome number evolution and inferred ancestral chromosome state in the trap-jaw ants inferred under Bayesian and Maximum likelihood optimization. Number at the nodes and respective colors (see label) present the inferred ancestral haploid chromosome. Numbers at the tips are the known haploid chromosome numbers of species. At right of each clade of Anochetus and Odontomachus are depicted the general chromosome morphology comprising the karyotypes. At each branch are highlighted the likely rearrangements undergone during karyotype evolution (see "Discussion" for details).
Support values for Bayesian Inference Posterior Probability (PP) and Maximum Likelihood (BS) with the respective groups of the genus Anochetus and Odontomachus.
Recent phylogenetic and molecular data are changing our knowledge about the relations between species and evolutionary processes resulting in the chromosome variation observed in ants (Hymenoptera: Formicidae). Ants exhibit remarkable variations in morphology, behavior, karyotypes, and chromosome structure. By assembling genetic and chromosome information about the trap-jaw ants from the subfamily Ponerinae, we reconstructed the phylogenetic relationships that inferred the monophyletic condition between the Anochetus and Odontomachus genera and estimated their ancestral haploid chromosome number. According to our inferences, these clades have an ancestral haploid chromosome number n = 15. The most recent common ancestor of Anochetus and Odontomachus has arisen between the Early Paleocene and the Early Eocene periods (time of the most recent common ancestor). In the Anochetus genus, we observed maintenance of the ancestral chromosome number estimated here in most species. This also suggests that pericentric inversions were the primary chromosomal rearrangement modulating the karyotype evolution of this genus. However, a reduction from n = 15–14 is observed in Anochetus emarginatus and Anochetus cf. madaraszi , which likely occurred by centromeric fusion. In contrast, the increase from the ancestral karyotype number in Anochetus horridus suggested centromeric fissions. Odontomachus showed maintenance of the ancestral chromosome number in the “ rixosus group” and several gains in all species from the “ haematodus group.” Our findings suggest that centromeric fissions and pericentric rearrangements lead to chromosomal changes in trap-jaw ants. Considering the ancestral state estimated here, changes in chromosome morphology are likely due to pericentric inversions, and chromosome number increases are likely due to centric fissions. The higher number of acrocentric or telocentric chromosomes in the karyotypes with n < 15 haploid chromosomes supports such an idea.
Studies that compile local ecological knowledge (LEK) on some of the various species of living beings observe biological data and are notably fundamental for effectively managing fisheries, supporting management strategies for protected areas, species conservation, and other factors. In this study, ethnoecological approaches were used to focus on the octopus Callistoctopus furvus (Gould, 1852), recently re-described and re-presented to the academic community more than a century after its discovery. The LEK of octopus fishers from different marine ecoregions of Brazil was compared to identify the distribution limits of the species along the Brazilian coast. Semi-structured interviews were conducted in 16 municipalities across four marine ecoregions located between the states of Ceará (northern limit) and Santa Catarina (southern limit), between March 2018 and August 2019. The results of the 187 interviews indicated a traditionality of fishing among artisanal octopus fishers, who are mostly men, although some are women who also share information on the fishing of C. furvus and hold leadership positions in the fishing colony. Cronbach’s alpha was used to analyze reliability of the form used in the interviews. A logistic regression model with binomial distribution was used to assess whether the probability of capturing the “eastern octopus” was associated with some of the interview variables. A cluster analysis based only on the respondents who caught the “eastern octopus” indicated the formation of groups and revealed greater dissimilarities among the fishers from the southeastern marine ecoregion of Brazil due to the fishing method used in the region. Heat maps showed that most of the information on the species was obtained in the eastern marine ecoregion of Brazil. The occurrence of the “eastern octopus” was recorded in all the studied Brazilian marine ecoregions. Moreover, this study revealed the relevant contribution of fishers’ knowledge to the distribution diagnosis of species with scarce scientific information.
The outbreak of Coronavirus disease 2019 (COVID-19) has become a global public health event. Effective forecasting of COVID-19 outbreak trends is still a complex and challenging issue due to the significant fluctuations and non-stationarity inherent in new COVID-19 cases and deaths. Most previous studies mainly focused on univariate prediction and ignored the uncertainty prediction of COVID-19 pandemic trends, which may lead to insufficient results. Therefore, this study utilized a novel intelligent point and interval multivariate forecasting system that consists of a distribution function analysis module, an intelligent point prediction module, and an interval forecasting module. Aimed at the characteristics of the COVID-19 series, eight hybrid models composed of various distribution functions (DFs) and optimization algorithms were effectively designed in the analysis module to determine the exact distribution of the COVID-19 series. Then, the point prediction module presents a hybrid multivariate model with environmental variables. Finally, interval forecasting was calculated based on DFs and point prediction results to obtain uncertainty information for decision-making. The new cases and new deaths of COVID-19 were collected from three highly-affected countries to conduct an empirical study. Empirical results demonstrated that the proposed system achieved better prediction results than other comparable models and enables the informative and practical quantification of future COVID-19 pandemic trends, which offers more constructive suggestions for governmental administrators and the general public.
| Diagrammatic representation of the SEIR model with the added class of "Detected" patients. Individuals move (denoted by solid arrows) from Susceptible to Exposed to Infected to Recovered, with the rates indicated above arrows in the figure. Some of the infected are detected (diagnosed/confirmed), indicated by the dashed arrow.
| (A) R 0 vs. HDI as an example of transmissibility dependence on demographic data (Pearson correlation denoted as R). (B) Pearson correlations of R 0 with (from left to right): social security and health insurance coverage (INS), percentage of urban population (UP), BUCAP measure of population density (BAP), median age (MA), infant mortality (IM), net migration (I-E), and percentage of refugee population by country or territory of asylum (RE). The statistical significance of each correlation is indicated in the legend, while "ns" stands for "no significance."
| (A) R 0 vs cholesterol level, as an example of a health-related parameter dependence. (B) Pearson correlation of R 0 with (from left to right): alcohol consumption per capita (ALC); the prevalence of obesity (OB); severity of COVID-19 relevant chronic diseases in the population (CD); a percentage of people with raised blood pressure (RBP); a percentage of smokers (SM); the prevalence of insufficient physical activity among adults (IN); BCG immunization coverage among 1-year-olds (BCG) (C) Correlation of blood types with R 0 in order: A, B, AB, and O (from left to right); overall value for that group, correlation only for Rh + subtype of the group, and correlation for Rh − subtype is shown. The two rightmost bars correspond to the overall correlation of Rh + and the overall correlation of the Rh − blood type with R 0 . The convention for representing the statistical significance of each correlation is the same as in Figure 4.
| (A) R 0 vs. the time delay of epidemic onset. (B) Pearson correlation of R 0 with pollutants (from left to right): NO 2 , SO 2 , CO, PM2.5, and PM10 (inhalable particles with 2.5 and 10 µm, respectively). (C) R 0 vs. precipitation. (D) Pearson correlation of R 0 with (from left to right): temperature, specific humidity, UV index, air pressure, and wind speed. The convention for representing the statistical significance of each correlation is the same as before.
It is hard to overstate the importance of a timely prediction of the COVID-19 pandemic progression. Yet, this is not possible without a comprehensive understanding of environmental factors that may affect the infection transmissibility. Studies addressing parameters that may influence COVID-19 progression relied on either the total numbers of detected cases and similar proxies (which are highly sensitive to the testing capacity, levels of introduced social distancing measures, etc.), and/or a small number of analyzed factors, including analysis of regions that display a narrow range of these parameters. We here apply a novel approach, exploiting widespread growth regimes in COVID-19 detected case counts. By applying nonlinear dynamics methods to the exponential regime, we extract basic reproductive number R 0 (i.e., the measure of COVID-19 inherent biological transmissibility), applying to the completely naïve population in the absence of social distancing, for 118 different countries. We then use bioinformatics methods to systematically collect data on a large number of potentially interesting demographics and weather parameters for these countries (where data was available), and seek their correlations with the rate of COVID-19 spread. While some of the already reported or assumed tendencies (e.g., negative correlation of transmissibility with temperature and humidity, significant correlation with UV, generally positive correlation with pollution levels) are also confirmed by our analysis, we report a number of both novel results and those that help settle existing disputes: the absence of dependence on wind speed and air pressure, negative correlation with precipitation; significant positive correlation with society development level (human development index) irrespective of testing policies, and percent of the urban population, but absence of correlation with population density per se . We find a strong positive correlation of transmissibility on alcohol consumption, and the absence of correlation on refugee numbers, contrary to some widespread beliefs. Significant tendencies with health-related factors are reported, including a detailed analysis of the blood type group showing consistent tendencies on Rh factor, and a strong positive correlation of transmissibility with cholesterol levels. Detailed comparisons of obtained results with previous findings, and limitations of our approach, are also provided.
Characteristics of the 372 study participants that responded to items regarding green space visited and reasons for visiting green spaces during the COVID-19 lockdown.
Change in frequency of use of urban green spaces during the COVID-19 lockdown explained by sociodemographic and green space characteristics variables.
Mobility restrictions imposed during the COVID-19 pandemic present a useful study system for understanding the temporal and spatial patterns of green space use. Here, we examine green space characteristics and sociodemographic factors associated with change in frequency of green space use before and during a COVID-19 lockdown in Brisbane, Australia drawing on a survey of 372 individuals. Applying regression analysis, we found that individuals who visited a different green space during lockdown than before tended to decrease their frequency of visits. In contrast, individuals who continued visiting their usual green space during lockdown were more inclined to increase their number of visits. Changes in frequency of green space use were also associated with particular characteristics of their usually visited green space. The presence of blue spaces and accessibility (carparks/public transport) were associated with increased frequency of use while foliage height diversity was associated with reduced frequency of use. We found that females were more likely to change their green space visitation frequency during COVID-19 compared to men and they also reported greater importance of green spaces for social and family interactions and spiritual reasons during COVID-19 compared to before. Males showed greater increases than females in the importance of green space for nature interactions and mental health benefits during the COVID-19 lockdown compared to before. Our results provide key insights for future resilient urban planning and policy that can fulfil a wide range of physical and psychological needs during a time of crisis and beyond.
The 2020 COVID-19 lockdown provides an opportunity to assess how the anthropause affected the behavior of birds. Black-headed gulls (Larus ridibundus) wintering at Dianchi Lake (Yunnan Province, southwestern China) prefer to forage on easily accessible human-provided food at various sites along the lake. Following the closure of the lake because of the pandemic, synthetic food was provided at a single location. We expected that the home range size and distribution of gulls would change in response to these changes in food provisioning. A total of 91 gulls were tagged with satellite transmitters in November 2018 and March 2019, and their movements were tracked during the winter months. We analyzed their home range size and spatial distribution in four periods, SCP2019, SOP2019, SCP2020, and SOP2020 (Scenic Opening/Closing Period in 2019/2020), and the difference between SOP2019 and SCP2019 was used as the control group. The eutrophication level in the wintering periods “Nov. 2018–Apr. 2019” and “Oct. 2019–Apr. 2020” was determined using the Normalized Difference Vegetation Index (NDVI), and the coverage ratio of algal blooms and NDVI were used as indicators of the amount of naturally available food. The home range sizes of gulls were reduced in SCP2020 compared with SOP2019, SCP2019, and SOP2020. The gulls were most abundant in the 600–900 m buffer zone and least abundant in the 0–300 m buffer zone in SCP2019; they were most abundant in the 0–300 m buffer zone and least abundant in the 900–2000 m buffer zone in SCP2020. These patterns were consistent with variation in the NDVI and the coverage ratio of algal blooms among buffer zones. Changes in wintering behaviors in SCP2020 relative to other periods suggested that gulls modified their behavior following anthropause-related changes in the distribution and provisioning of food. Our findings provide insights into the role of behavioral plasticity in mediating adaptation to changes in human activities in birds.
| Examples of current positive (green) and negative (red) contributions of horseshoe bat (A) and waterfowl (C) trade to the SDGs, and how context and species-specific policy responses could improve delivery of SDG outcomes (B,D). Thickness of lines represents the relative size of the costs/benefits, based on the qualitative assessment conducted by the authors in Table 1.
| A general process and key considerations for developing risk-based wildlife trade policy for sustainable development outcomes.
The COVID-19 pandemic has caused huge loss of life, and immense social and economic harm. Wildlife trade has become central to discourse on COVID-19, zoonotic pandemics, and related policy responses, which must focus on “saving lives, protecting livelihoods, and safeguarding nature.” Proposed policy responses have included extreme measures such as banning all use and trade of wildlife, or blanket measures for entire Classes. However, different trades pose varying degrees of risk for zoonotic pandemics, while some trades also play critical roles in delivering other key aspects of sustainable development, particularly related to poverty and hunger alleviation, decent work, responsible consumption and production, and life on land and below water. Here we describe how wildlife trade contributes to the UN Sustainable Development Goals (SDGs) in diverse ways, with synergies and trade-offs within and between the SDGs. In doing so, we show that prohibitions could result in severe trade-offs against some SDGs, with limited benefits for public health via pandemic prevention. This complexity necessitates context-specific policies, with multi-sector decision-making that goes beyond simple top-down solutions. We encourage decision-makers to adopt a risk-based approach to wildlife trade policy post-COVID-19, with policies formulated via participatory, evidence-based approaches, which explicitly acknowledge uncertainty, complexity, and conflicting values across different components of the SDGs. This should help to ensure that future use and trade of wildlife is safe, environmentally sustainable and socially just.
| The mean selected desire to own of pet-owning respondents in Brazil, China, the USA, and Vietnam, in 2018, prior to the inception of COVID-19 (black, filled symbols) and in July 2020 (open symbols) for (A) mammal species, (B) bird species, and (C) reptile species.
We wished to assess whether the COVID-19 pandemic, thought to have a zoonotic origin, may lead to a reduction in consumer demand for wildlife products. In 2018, we surveyed the effect of demand reduction messaging on consumers' desire to own exotic pets with 1,000 respondents in each of Brazil, China, the USA, and Vietnam. In July 2020, during the pandemic, we repeated the survey with 100 new respondents in each country. Mean desire to own a given exotic pet was 40–60% lower in 2020 during the pandemic, but only for respondents from Brazil, China, and the USA, and only for the group of respondents who had high a priori purchase likelihoods: those who had already owned an exotic pet. The stated desire to own of non-owners was no different in 2020, but this group already had extremely low purchase likelihoods. Vietnamese pet owners, in contrast to those in other countries, exhibited higher purchase desire during the pandemic than previously. We speculate that this arose because Vietnam has a long history of dealing with epidemic disease, had no COVID-19 related deaths by the time of survey, and so population uncertainty about the consequences of exotic pet ownership may have decreased. While limited, our initial evidence indicates that the global pandemic is unlikely to permanently curb demand for wildlife products.
Previous studies have estimated the influence of control measures on air quality in the ecological environment during the COVID-19 pandemic. However, few have attached importance to the comparative study of several different periods and evaluated the health benefits of PM2.5 decrease caused by COVID-19. Therefore, we aimed to estimate the control measures' impact on air pollutants in 16 urban areas in Beijing and conducted a comparative study across three different periods by establishing the least squares dummy variable model and difference-in-differences model. We discovered that restriction measures did have an apparent impact on most air pollutants, but there were discrepancies in the three periods. The Air Quality Index (AQI) decreased by 7.8%, and SO2, NO2, PM10, PM2.5, and CO concentrations were lowered by 37.32, 46.76, 53.22, 34.07, and 19.97%, respectively, in the first period, while O3 increased by 36.27%. In addition, the air pollutant concentrations in the ecological environment, including O3, reduced significantly, of which O3 decreased by 7.26% in the second period. Furthermore, AQI and O3 concentrations slightly increased compared to the same period in 2019, while other pollutants dropped, with NO2 being the most apparent decrease in the third period. Lastly, we employed health effects and environmental value assessment methods to evaluate the additional public health benefits of PM2.5 reduction owing to the restriction measures in three periods. This research not only provides a natural experimental basis for governance actions of air pollution in the ecological environment, but also points out a significant direction for future control strategies.
| (A) Nei's unbiased distance values and (B) pairwise F ST values are depicted between all regions. Due to the small sample size of the SouthBiscayneBay region (n = 3), samples from this region have been excluded from these analyses. Detailed results for each dataset are presented in Supplementary Tables 2, 3 (Nei's and F ST , respectively) and distributions are plotted in Supplementary Figures 1, 2 (Nei's and F ST , respectively). Line color indicates the type of region pair: nursery region to nursery region (red), nursery region to spawning region (purple), or spawning region to spawning region (blue). Line width indicates genetic distance with greater genetic distance or higher F ST illustrated with a narrower connecting line. Please note that these lines solely represent pairwise values, not movement of individual shrimp between regions. Spawning regions are labeled in yellow (Base map from Google Earth).
| (A) Principal component analysis (PCA; PC1 and PC2 explain 4.1 and 4.0%, respectively). (B) Discriminant Analysis of Principal Components (DAPC), and (C) Neighbor Joining Tree (NJ) of the batch161 dataset. All seven regions are represented and points are color-coded by collection site. (D) STRUCTURE results are reported for all seven regions (reported beneath the plot) for batch161. K = 2 was deemed optimal using the Evanno method. Results across all nine datasets are presented in Supplementary Figures 3-6 (PCAs, DAPCs, Njs, and STRUCTURE plots, respectively).
| The number of private alleles, normalized by each region's sample size (referred to as PA norm in-text), are presented for each region. Detailed results for each dataset are presented in Supplementary Table 4. Box color indicates the type of region: nursery region (white) or spawning region (blue). Outliers are red.
Details of the assembled and quality-filtered ddRADseq datasets are presented.
The Gulf of Mexico pink shrimp, Farfantepenaeus duorarum , supports large fisheries in the United States and Mexico, with nearly 7,000 tons harvested from the region in 2016. Given the commercial importance of this species, management is critical: in 1997, the southern Gulf of Mexico pink shrimp fishery was declared collapsed and mitigation strategies went into effect, with recovery efforts lasting over a decade. Fisheries management can be informed and improved through a better understanding of how factors associated with early life history impact genetic diversity and population structure in the recruited population. Farfantepenaeus duorarum are short-lived, but highly fecund, and display high variability in recruitment patterns. To date, modeling the impacts of ecological, physical, and behavioral factors on juvenile settlement has focused on recruitment of larval individuals of F. duorarum to nursery grounds in Florida Bay. Here, we articulate testable hypotheses stemming from a recent model of larval transport and evaluate support for each with a population genomics approach, generating reduced representation library sequencing data for F. duorarum collected from seven regions around the Florida Peninsula. Our research represents the first and most molecular data-rich study of population structure in F. duorarum in the Gulf and reveals evidence of a differentiated population in the Dry Tortugas. Our approach largely validates a model of larval transport, allowing us to make management-informative inferences about the impacts of spawning location and recruitment patterns on intraspecific genetic diversity. Such inferences improve our understanding of the roles of non-genetic factors in generating and maintaining genetic diversity in a commercially important penaeid shrimp species.
Extreme climate events have a greater impact on natural and human systems than average climate. The spatial and temporal variation of 16 temperature and nine precipitation extremal indices was investigated using the daily maximum and minimum surface air temperature and precipitation records from 113 meteorological stations in China’s arid regions from 1960 to 2016. The warmth indices [warm spell duration (WSDI); numbers of warm nights, warm days, tropical nights (TR), and summer days (SU)] increased significantly. On the contrary, the cold indices [numbers of frost days (FD), ice days (ID), cool days, and cool nights; cold spell duration (CSDI)] decreased significantly. The number of FD decreased fastest (−3.61 days/decade), whereas the growing season length (GSL) increased fastest (3.17 days/decade). The trend was strongest for diurnal temperature range (DTR) (trend rate = −7.29, P < 0.001) and minimum night temperature (trend rate = 7.70, P < 0.001). The cold extreme temperature events increased with increasing latitude, but the warm extreme temperature events decreased. Compared with temperature indices, the precipitation indices exhibited much weaker changes and less spatial continuity. Overall, changes in precipitation extremes present wet trends, although most of the changes are insignificant. The regionally averaged total annual precipitation for wet days increased by 4.78 mm per decade, and extreme precipitation events have become more intense and frequent during the study period. The spatial variability of extreme precipitation in the region was primarily influenced by longitude. Furthermore, the climate experienced a warm-wet abrupt climate change during 1990s.
Meteorological station data from 1961 to 2016 in the Sichuan Yellow River Source (SYRS) was used to analyze the trends in precipitation and temperature. The Thornthwaite Memorial model and GIS technology were used to calculate the response of pasture productivity to climate change. A climate prediction model of pasture productivity was established to predict its response to precipitation and temperature. The results showed that: (1) the annual precipitation presents a slight downward trend, at a rate of −10.16 mm⋅(10a)–1. The average annual temperature exhibited an upward trend, at (10a)–1, and the productivity of herbage exhibited a linearly increasing trend, with a rate of increase of 80.07 g⋅m–2⋅(10a)–1. (2) In terms of spatial distribution, the pasture productivity decreased from southwest to northeast. The influence of temperature on pasture productivity was greater than that of precipitation in the SYRS. (3) The “warm-wet” climate was conducive to increasing pasture productivity. The annual average temperature was predicted to increase by 1 or 2°C, and the annual average precipitation was predicted to increase by 10 or 20% with an average increase between 7.15 and 14.30%. (4) Grassland degradation continues to occur and ecological restoration measures should be implemented to control grassland degradation.
The taxonomy of Premnobiini is reviewed in the context of a molecular phylogeny including species of Ipini, Dryocoeotini, and Xyleborini. DNA data from COI, 16S, 28S, and CAD (~2640 characters) were generated for 79 species. Parsimony and Bayesian methods, using multiple sequence alignment methods and partitioning regimes, were used to reconstruct the phylogeny. The resulting topologies are generally congruent. Ipini is monophyletic along with all genera except Acathotomicus. Premnobiini is nested within Ipini and consists of two clades, which associate with the type species of Premnobius and Premnophilus, and with morphological diagnostic characters. The following taxonomic changes are made based on the recovered relationships. Premnophilus is resurrected as a valid genus and Premnobiini is considered a sub-tribe of Ipini.
| A virtual window into a 2.5D world. (A) Integrating three-dimensional animal movement tracks with the mapping of these complex three-dimensional habitats, will enable us to study how animals navigate the branching structures of their arboreal environments. (B) Vertical movement track over time of an arboreal kinkajou (Potos flavus) in reference to ground (brown solid line) tracked on Barro Colorado Island, Panama, and canopy height (green dashed line). GPS data were sampled at 1 Hz and dots represent 1-min median values. The solid black line represents a running median of the height measurements over a 15-min interval. (C) Based on the animal's horizontal movements we can extract where in the canopy animals move over the course of the day. Spider monkeys (Ateles geoffroyi, red) tend to stay in higher canopy areas, while coatis (Nasua narica, blue), capuchins (Cebus capucinus, purple), and kinkajous (yellow) move through areas with lower canopy heights. The averages (and 95% CI shading) over the active period for four arboreal mammals species: coati (blue, N = 17 individuals), kinkajou (purple, N = 13 individuals), capuchin (yellow, N = 8 individuals), and spider monkey (red, N = 8 individuals) are presented. Each line represents the cumulative average values smoothed over 15-min of the individuals of a single species during the activity time of the individuals. Sources of DEM (digital elevation model) and canopy height data (Havmøller et al., 2021). Coatis sleep high in trees and descend to the ground in the mornings, forage on the ground during the day to return up into the trees at night (Kaufmann, 1962). Kinkajous and capuchins stay within the canopy and are known to only rarely come to the ground. Spider monkeys spend the majority of their day high in the canopy and have the least overall variation in vertical positioning. (D) Sensei-Panama visualization in CAVE2, visualizes animal movement trajectories within a virtual tropical environment, reconstructed from sensor and image data. Animal movements are shown with points connected by lines.
The complex, interconnected, and non-contiguous nature of canopy environments present unique cognitive, locomotor, and sensory challenges to their animal inhabitants. Animal movement through forest canopies is constrained; unlike most aquatic or aerial habitats, the three-dimensional space of a forest canopy is not fully realized or available to the animals within it. Determining how the unique constraints of arboreal habitats shape the ecology and evolution of canopy-dwelling animals is key to fully understanding forest ecosystems. With emerging technologies, there is now the opportunity to quantify and map tree connectivity, and to embed the fine-scale horizontal and vertical position of moving animals into these networks of branching pathways. Integrating detailed multi-dimensional habitat structure and animal movement data will enable us to see the world from the perspective of an arboreal animal. This synthesis will shed light on fundamental aspects of arboreal animals’ cognition and ecology, including how they navigate landscapes of risk and reward and weigh energetic trade-offs, as well as how their environment shapes their spatial cognition and their social dynamics.
| Spatial-temporal patterns of animal assemblages (Number of Identified Specimen) from sites dating to 7500-2000 BP in Yellow River Valley. (a) Animal assemblages from sites dating to 7500-7000 BP. (b) Animal assemblages from sites dating to 7000-6000 BP. (c) Animal assemblages from sites dating to 6000-5000 BP. (d) Animal assemblages from sites dating to 5000-4000 BP. (e) Animal assemblages from sites dating to 4000-3000 BP. (f) Animal assemblages from sites dating to 3000-2000 BP.
| Variation in the NISP (Number of Identified Specimen) percentages of faunal remains representing different habitats, compared with climate and vegetation changes, and the summed probability distribution of original radiocarbon dates from 8000 to 2000 BP. (A) North China temperature record (Hou and Fang, 2012). (B) Pollen-based annual precipitation regime, reconstructed from Gonghai Lake (Chen et al., 2015b). (C) Synthesized standard curve of tree pollen percentages in the monsoon margin region (lying between forest and steppe) (Zhao and Yu, 2012). (D) Summed probability distribution of original radiocarbon dates from 8000 to 2000 BP, revealing the trends and fluctuations in human population (Dong et al., 2019). (E) NISP percentage of livestock remains and wild mammal remains representing different habitats.
The mid-late Holocene witnessed the rapid development of Neolithic and Bronze cultures in the Yellow River Valley (YRV) of northern China. Spatio-temporal patterns of plant utilization during this period and its influencing factors have been intensively discussed, whereas the variation in animal exploitation in relation to climate change and human activities has not been adequately studied. In this paper, we reviewed zooarchaeological data obtained from 38 Neolithic and Bronze sites in YRV, and compared them with paleoclimate and archaeological records, to reconstruct the trajectory of animal utilization in this area between 7500 and 2000 BP and discern the influencing factors driving it. The results revealed that animal exploitation was mainly sourced from wildlife between 7500 and 6000 BP, shifting to omnivorous livestock sources in the period of 6000–4000 BP except in the northeast Tibetan Plateau. During 4000–2000 BP, however, omnivorous and herbivorous livestock had come to dominate humans' subsistence on animals, which nonetheless showed substantial spatio-temporal variation in the YRV. Further analysis suggests that animal exploitation in the Neolithic and Bronze YRV were both directly affected by human activities, while climate change might have influenced the environment surrounding human settlements and, indirectly, their choice of animals to exploit. This work provides new perspectives for exploring the changing patterns of human-environment interactions in the YRV during the mid-late Holocene.
| Left side: The map of the study area located in SW Greece (36 • 58 N, 21 • 40 E), showing the different observation points (red dots), and the major sub-areas. It also contains information about the water connections. Right side: Birds' migration "national" routes in Greece (Hellenic forestry, 2020) along the Mediterranean/Black Sea Flyway (BirdLife International, 2017), and a picture of the site which captures one of the drainage canals in the form that it looks today.
| Graph by Maneas et al. (2019), showing monthly mean precipitation (MAP), evaporation rate (MAE) and temperature (MAT) at the study area for the period 1956-2011. At the bottom, a graph showing the birds' periods and seasons used for the analyses.
| Number of monthly recorded species in the GLw-Natura2000 based on counts during the period November 2016-January 2019.
| Stacked column graph showing the spatial distribution (percentage) of waterbirds' categories in the different sub-areas of the GLw-Natura2000 area, based on their average population distribution during the different periods. The abundance (mean, minimum and maximum values) of each waterbirds category during the same period is presented in the table at the bottom of each graph.
Located at the south-western most part of the Balkan peninsula, along an important migration route (the Mediterranean/Black Sea Flyway), the Gialova Lagoon wetland is one of the few remaining Important Bird Areas (IBAs) along the south-west coast of Greece, also designated as a Special Protection Area. The wetland serves as the first suitable stopover for many spring migrants who have flown non-stop over the Mediterranean Sea, and the last before their journey back to Africa in the autumn. In this study, we conducted monthly field visits during the period October 2016 to January 2019 with the aim to complement existing information about the site, to evaluate the current status and distribution of waterbirds, to provide insights for the management of the area and to re-assess the IBA/Ramsar criteria. A total of 149 bird species representing 43 families and 15 orders were recorded, including 36 threatened species at an International, European or/and national level, and 40 species listed in the Annex I of the EUs Birds Directive (21 species were listed as both threatened and under Annex I). 81 species were identified as wetland related species, of which 66 species were identified as waterbirds (7 orders, 11 families). Waterbirds richness and abundance were higher during the Wet season and corresponding periods (Wintering and Spring migration). All parts of the wetland supported waterbirds and threatened species, with the S. Wetland sub-area being the most diverse during the Breeding/Nesting, and both migration periods. The abundance of most waterbirds and IBA species have declined over the last 20 years, but this does not necessarily mean that the area no longer fulfills Ramsar criterion 6 (and equivalent IBA criterion A4i). However, this outcome should not be overlooked by the site managers and conservation actions, such as the restoration of fresh water inflows which could improve habitats and water conditions for IUCN and IBA species, should be implemented with high priority. In addition, our results indicate that the area meets Ramsar criterion 4 and criterion 2, and thus we suggest that it should be further investigated and evaluated to potentially become the eleventh Greek Ramsar site.
Vegetation is essential for maintaining urban ecosystems, climate regulation, and resident health. To explore the variations in city-level vegetation greening (VG) and its relationship to urban expansion, VG in 439 Chinese cities was extracted using the Theil–Sen and Mann–Kendall algorithms based on Moderate Resolution Imaging Spectroradiometer EVI (enhanced vegetation index) data from 2001 to 2020. The spatial variations in VG and its patterns, as well as its relationship with urban expansion, were then analyzed. The following results were obtained: (1) cities with larger greening areas were primarily located in the central and eastern provinces of China, followed by the southeastern, southwestern, and western provinces. The 48 cities with the largest greening areas accounted for 60.47% of the total greening area. (2) VG patches in northern China exhibited better integrity. (3) The centralization trend of VG was evident; the location of VG patterns was influenced by the form of urban expansion. (4) The intensity of artificial impervious area expansion had a weak negative correlation with the VG. Therefore, we must enhance vegetation in new urban areas to improve the spatial balance of VG. The present results of this study can provide a foundation for developing effective policies for the construction and management of urban greenery projects.
| (A) Geographic location of study area, (B) soil types, (C) digital elevation model (DEM) and sampling transects across the basins of Datong (cool-temperate transect), Taiyuan (mid-temperate transect), and Yuncheng (warm-temperate transect), (D) soil sampling locations in 2007, and (E) soil sampling locations in 2017.
| The spatial distribution of temporal change of soil nitrogen density (SND T ) and the local wavelet spectra of SND T along the (A) cool-temperate, (B) mid-temperate, and (C) warm-temperate transects. The solid black lines in the local wavelet spectra show SND T variation with >1 standard deviation, and the numbers in the bracket represent the area of significant variations.
| Correlation coefficients between the temporal change of soil nitrogen density (SND T ) and its controlling factors or their decomposed scale components by continuous wavelet transform (CWT) along the (A) cool-temperate, (B) mid-temperate, and (C) warm-temperate transects. The x-axis indicates the original scale or the decomposed scales of the environmental factors.
| Partial wavelet coherency (PWC) between the temporal change of soil nitrogen density (SND T ) and single predictor variable after excluding the effect of the other variables along the (A) cool-temperate (slope), (B) mid-temperate (SSD), and (C) warm-temperate (SSD) transects. The direction of the arrow shows the type of correlation (the right direction is positive and the left direction is negative), and the solid black lines show significant bivariate wavelet coherence (BWC) at a 95% confidence level.
Soil nitrogen density (SND), which is influenced by environmental factors operating at different spatial scales and intensities, is critical for agricultural production and soil quality. Although the spatiotemporal distribution of top-layer SND has been well explored, the scale effects of environmental factors on the temporal changes of SND (SNDT) are poorly studied, which might promote the predictive accuracy of SNDT. Thus, SNDT during a certain period was calculated to explore the multiscale effects of environmental factors on it. In the study, three sampling transects under the basins of warm-temperate, mid-temperate, and warm-temperate zones were established with 200 km long and 1 km intervals to explore the spatial variation of SNDT, examine the multiscale effect of environmental factors on it, construct the predicting models based on its scale-specific relations with environmental factors, and validate the models in each basin or in other climate-zone basins. The results indicated that the increment of SND during a certain period was the greatest in the mid-temperate basin, and the variation of SNDT was ranked as cool-temperate > mid-temperate > warm-temperate basins. Under different soil types, the spatial characteristics of SNDT were different in different climate-zone basins, but the average SNDT under cropland was the greatest in each basin. Considering the influencing factors (climatic, topographic, and vegetation factors), they had controls on SNDT operating at different spatial scales. In regard to the prediction of SNDT, the method of partial least square regression (PLSR) combined with a multiscale analysis was found to be more preferable for dependent SNDT prediction than the traditional method of stepwise multiple linear regression but could not be validated for the independent validation data in other basins. Thus, the spatial multiscale relations of SNDT with environmental factors could provide more information for each basin, and the integration of the extra information decomposed by wavelet transform into the method of PLSR could enhance the SNDT prediction for dependent datasets. These findings are of great significance for future studies in the spatial modeling of SND temporal dynamics under the influence of environmental changes.
Under the background of global climate change, the impact from drought on the ecosystem exhibits the characteristics of complexity and multi-process, especially for the main component, which is the grassland ecosystem of the overall ecosystem. Identifying past droughts and predicting future ones is vital in limiting their effects. However, the random and non-linear nature of drought variables makes accurate drought prediction still a challenging scientific problem. In this study, the boundaries, Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI) of Asian Grassland Ecosystem (AGE) were obtained by Google Earth Engine (GEE), which were used to construct LST-EVI feature spaces to calculate the dry-wet edge fitting equations and Temperature Vegetation Drought Index (TVDI). Mann–Kendall test and Sen trend degrees were further used to analyze the drought trend of AGE. The results showed that there were obvious spatial differences in the wet and dry conditions of AGE, which showed that the TVDI increased from east to west and from north to south, with humid areas mainly concentrated in northern Asia and severe drought areas concentrated in southern Asia. From 2010 to 2018, the area of humid areas and severe drought areas of AGE decreased, and some humid areas changed to normal areas or even drought areas, while the drought in severe drought areas was alleviated. The results of the Sen trend test further show that the aggravating trend of drought in severe drought areas of South Asia is relatively low, and some areas show a trend of changing to humidity. However, there is an obvious aggravating trend of drought in humid areas or low drought areas of South Asia, these areas should also be the focus areas for drought prevention in the future. This study identified the spatio-temporal distribution characteristics and evaluated the evolution trend of the drought of AGE, which is of great significance to the management and prevention of drought of AGE.
FIGURE The ee-m wind in n synoptic patterns during gggg-----in North China.
Urban ozone (O 3 ) pollution has become a prominent environmental threat to public health while the relationship between O 3 formation and driving factors remains elusive, particularly for megacities in the Shandong Peninsula of China. In this study, we use intensive ambient measurements of trace gases to comprehensively investigate the magnitude of O 3 pollution in Jinan city from 2013 to 2020. Further, emission inventory and OMI NO 2 columns are used for probing changes in precursor emissions. Ground-level measurements indicate degraded O 3 air quality afterward in 2015 and depict city-wide elevated O 3 levels (higher than 140 μg/m ³ in the warm season). For precursor emissions, it is found that NO x emissions have decreased more than 30% due to successful regulation efforts, which is in excellent agreement with NO 2 columns from OMI. The method of objective synoptic weather pattern classification [T-Mode principal component analysis (PCT)] is adopted to distinguish the associated meteorological parameters under various synoptic patterns which govern the variability in regional O 3 levels. Among identified synoptic patterns, Type 2 and Type 8 featured by low sea level pressure (SLP), high temperature, and strong ultraviolet radiation are the most prevalent synoptic patterns in spring and summer, respectively, which are prone to the occurrence of O 3 exceedances. This work provides a detailed view of long-term O 3 levels and the relationship between precursors and meteorological conditions in a typical densely populated city in northern China, showing implications for developing O 3 mitigation strategies.
| The extent of the fires (a) is shown over a Google Earth satellite image. The fire extent (from the Commonwealth National Indicative Aggregated Fire Extent Dataset) is outlined in white, and dark green regions on the image represent pre-fire closed forests. Areas where conservation units could not be assigned across the 59 species assessed, due to a lack of genetic samples, are shown in panel (b) (from Catullo and Moritz, 2020). Colour indicates the number of species in a grid cell for which populations from that area could not be assigned to a conservation unit, with the fire extent shown in the polygons.
Environmental catastrophes are increasing in frequency and severity under climate change, and they substantially impact biodiversity. Recovery actions after catastrophes depend on prior benchmarking of biodiversity and that in turn minimally requires critical assessment of taxonomy and species-level diversity. Long-term recovery of species also requires an understanding of within-species diversity. Australia’s 2019–2020 bushfires were unprecedented in their extent and severity and impacted large portions of habitats that are not adapted to fire. Assessments of the fires’ impacts on vertebrates identified 114 species that were a high priority for management. In response, we compiled explicit information on taxonomic diversity and genetic diversity within fire-impacted vertebrates to provide to government agencies undertaking rapid conservation assessments. Here we discuss what we learned from our effort to benchmark pre-fire taxonomic and genetic diversity after the event. We identified a significant number of candidate species (genetic units that may be undescribed species), particularly in frogs and mammals. Reptiles and mammals also had high levels of intraspecific genetic structure relevant to conservation management. The first challenge was making published genetic data fit for purpose because original publications often focussed on a different question and did not provide raw sequence read data. Gaining access to analytical files and compiling appropriate individual metadata was also time-consuming. For many species, significant unpublished data was held by researchers. Identifying which data existed was challenging. For both published and unpublished data, substantial sampling gaps prevented areas of a species’ distribution being assigned to a conservation unit. Summarising sampling gaps across species revealed that many areas were poorly sampled across taxonomic groups. To resolve these issues and prepare responses to future catastrophes, we recommend that researchers embrace open data principles including providing detailed metadata. Governments need to invest in a skilled taxonomic workforce to document and describe biodiversity before an event and to assess its impacts afterward. Natural history collections should also target increasing their DNA collections based on sampling gaps and revise their collection strategies to increasingly take population-scale DNA samples in order to document within-species genetic diversity.
| Territories ceded to the United States in the Treaties of 1836, 1837, 1842, and 1854 in which Ojibwe tribes ceded the outlined lands and reserved the rights to hunt, fish, and gather to maintain their lifeway. GLIFWC member tribes are in red [(1) Bad River, (2) Bay Mills, (3) Fond du Lac, (4) Keweenaw Bay, (5) Lac Courte Oreilles, (6) Lac du Flambeau, (7) Lac Vieux Desert, (8) Mille Lacs, (9) Mole Lake, (10) Red Cliff, and (11) St. Croix]. *The ceded territory and reservation boundaries are representations and may not be the legally binding boundary. Map created using Ceded Territories Boundary Version 2.1.
In February 2021, the Wisconsin DNR implemented a wolf season in which > 20% of the population was killed in 63 h. Wisconsin’s Ojibwe tribes had a visceral reaction to this killing. This paper provides a perspective for this reaction by reviewing the Ojibwe relationship with Ma’iingan. This relationship maintains that Ma’iingan and Ojibwe are to be considered relatives whose fates are intertwined. Ma’iingan and Ojibwe have lived parallel histories, suffering from the effects of colonization, the decimation of wolf populations and decline of tribal culture. The Ojibwe tribes ceded vast territories in treaties with the United States while retaining common use rights, including the right to hunt and fish. These rights were reaffirmed just as wolves were reestablishing themselves in Wisconsin. The tribes continue to strengthen their culture, while wolf populations continue to recover. By examining these comparative histories, it becomes apparent that “whatever happens to one happens to the other.” Unfortunately, Ma’iingan were not adjudicated during the Wisconsin treaty case, creating uncertainty over how the relationship between the Ojibwe and Ma’iingan is to be respected by the state. The tribes believe their treaty right includes protection for wolves, so that wolves can fulfill their cultural and ecological purposes. Tribes maintain that Ma’iingan should determine their own population levels, in order to provide ecological and cultural benefits. A respectful and appreciative relationship with Ma’iingan should be maintained so that the future well-being of both Ma’iingan and the Ojibwe will be assured.
How strong was the anthropogenic imprint in the disturbance regime of eastern Canadian mixed forests during the 20th century? And how did it alter the tree species composition? To answer these questions, we reconstructed the 20th century anthropogenic disturbance regime and analyzed its impact on modern forest composition using historical and modern forest inventory and map data. Between 1895 and 2005, an equivalent of 144% of the study area has been logged and 19% burned. The logging rotation period has shortened from 152 years in 1895–1935 to 47 years in 1965–2005, due to increased industrial capacity. The fire rotation period decreased from 1668 years in 1895–1925 to 200 years during the peak of human settlement (1925–1955), and then increased to 2925 years in 1955–2005. The geographical progression of anthropogenic disturbances in the landscape has reflected the socio-economic context. During the 20th century, logging moved inland from the margins of the main water courses, reflecting the shift in wood transport from log driving on rivers to the densification of the road network in the second half of the 20th century. Most fires were located at low altitude, close to private lands suggesting ignitions from anthropogenic origins. Fire prone species (poplars) are mostly found within burned areas. Despite these disturbances, forest composition remained relatively stable, suggesting resilience of regional forest ecosystems.
Spruce budworm (SBW) outbreaks are a major disturbance in North American forests. In Quebec, Canada, the recent history of SBW outbreaks at the local scale is well-known. Studies at the Québec scale nonetheless remain rare despite the need to better understand the dynamics of SBW outbreaks at a larger scale. This study aimed to reconstruct the spatiotemporal dynamics of SBW outbreaks during the 20th century across the insect's range in southern Quebec. To this end, we sampled 83 stands throughout southern Quebec. These stands were selected according to their age and the presence of black, white, and red spruce. In fact, spruce, unlike balsam fir, survives the SBW outbreaks and can record them in these growth rings. In each stand, cores were taken from 20 spruce trees. The dendrochronological series of more than 1,600 trees were analyzed, and we identified, through the k-means grouping of stands, the spatial patterns of tree growth for the three previously documented 20th century SBW outbreaks. The outbreaks were not homogeneous across the distribution range of the insect. Two groups of stands showed early- (1905–1930) and late-century (1968–1988) outbreaks of high severity and a mid-century (1935–1965) outbreak of moderate severity. This pattern is explained mainly by the presence of the insect within the balsam fir–yellow birch and balsam fir–white birch bioclimatic domains, areas where outbreaks tend to be most severe because of the abundance of balsam fir, the main SBW host species. However, these two models differ in terms of the duration of outbreaks. A third, more northern, cluster of stands experienced lower severity outbreaks over the 20th century, a pattern explained by a lower proportion of balsam fir trees in these landscapes. Our study shows that, on the one hand, these three groups of stands are defined by outbreaks of specific duration (an outbreak period beginning when more than 20% of the trees are affected and ending when <20% of the trees are affected) and severity (in terms of percentage of affected trees), and on the other hand they are spatially distinct and subject to different climatic conditions.
The possible role of avian predators in limiting songbird populations has been largely discounted since the publication of findings showing a lack of statistical association in United Kingdom bird census data between changes in prey species populations and those of a range of predatory species, including raptors and corvids. I re-applied the methodology behind these findings, covering a wider range of prey species and using site-level modeling to estimate predator abundance instead of a mixture of spatial modeling and raw count data. A significant aggregate predator effect was found in 33 out of 40 prey species, compared to only 10 out of 27 in the original study, as well as a higher rate of significant individual predator effects, with 41 significantly negative and 84 significantly positive effects out of a total of 320. The greater explanatory power of predator variables estimated using site-level modeling suggests that this has significant advantages over the use of predator variables derived from spatial modeling, which may not capture variation in predator abundance at a local scale, or from raw count data, which may lead to attenuation of effect estimates. The prevalence of positive associations between predators and prey is consistent with a common response to local habitat variation, which may absorb negative covariance resulting from the impact of predators on prey populations. Both positive and negative predator-prey associations may also occur as a result of independent demographic processes that manifest as sequential habitat occupation or withdrawal. Analyses of census data cannot discriminate among these possible scenarios and may therefore have limited value in determining whether predators have been limiting prey populations. Inference to a lack of impact of avian predators on prey populations from such analyses may therefore be unsafe, and a role for increased predator numbers remains a viable hypothesis with respect to bird population declines. The recent neglect of this possibility should therefore be urgently reversed, with a particular need for field experiments that can support strong inference regarding population limitation of songbirds by avian predators.
One of the most useful metaphors for driving scientific and engineering progress has been that of the “machine.” Much controversy exists about the applicability of this concept in the life sciences. Advances in molecular biology have revealed numerous design principles that can be harnessed to understand cells from an engineering perspective, and build novel devices to rationally exploit the laws of chemistry, physics, and computation. At the same time, organicists point to the many unique features of life, especially at larger scales of organization, which have resisted decomposition analysis and artificial implementation. Here, we argue that much of this debate has focused on inessential aspects of machines – classical properties which have been surpassed by advances in modern Machine Behavior and no longer apply. This emerging multidisciplinary field, at the interface of artificial life, machine learning, and synthetic bioengineering, is highlighting the inadequacy of existing definitions. Key terms such as machine, robot, program, software, evolved, designed, etc., need to be revised in light of technological and theoretical advances that have moved past the dated philosophical conceptions that have limited our understanding of both evolved and designed systems. Moving beyond contingent aspects of historical and current machines will enable conceptual tools that embrace inevitable advances in synthetic and hybrid bioengineering and computer science, toward a framework that identifies essential distinctions between fundamental concepts of devices and living agents. Progress in both theory and practical applications requires the establishment of a novel conception of “machines as they could be,” based on the profound lessons of biology at all scales. We sketch a perspective that acknowledges the remarkable, unique aspects of life to help re-define key terms, and identify deep, essential features of concepts for a future in which sharp boundaries between evolved and designed systems will not exist.
| Location of the tree-ring sites in European Russia. KOLA-summer temperature reconstruction (1600-2004, Kononov et al., 2009), MR-SPEI reconstruction (1790-2014, Matskovsky et al., 2016b), CAU-summer temperature reconstruction (1596-2011, Dolgova, 2016). Long tree-ring chronologies are described in Figure 2. Grayscale shading shows elevation.
| Replication of long chronologies in European Russia. Note different axes. For the locations see Figure 1. *Higher length and replication are reported by Tarabardina et al. (2016): 9th-19th centuries, 6,505 dated samples in total.
In this review, we have focused on the following key points: (1) living trees in European Russia and their climatic sensitivity. Species suitable for tree-ring analyses, their age limits, spatial distribution of temperature- and drought-sensitive trees, and the available tree-ring chronologies. (2) Extension of the living-tree chronologies using archeological and architectural samples. Dendrochronological dating of archeological and cultural monuments. (3) Tree-ring-based climatic reconstructions in European Russia. European Russia drought atlas. (4) Climatic and environmental reconstructions in the Northern Caucasus. (5) Dendroecology. We also briefly summarized the problems and prospects of tree-ring research in European Russia.
The relationship between archeological culture and ethnicity is invariably complex. This is especially the case for periods of national division and rapid inter-ethnic exchange, such as China’s Sixteen Kingdoms (304–439 CE) and Northern and Southern Dynasties (420–589 CE). Going by tomb shape and grave goods, the Foyemiaowan cemetery at Dunhuang exhibits a typical third–tenth century Han style. Despite this, the ethnic makeup of the Foyemiaowan population has remained unclear. We therefore analyzed 485 Y-chromosomal SNPs and entire mitochondrial genomes of 34 Foyemiaowan samples. Our study yielded the following discoveries: (1) principal component analysis revealed that the Foyemiaowan population was closely clustered with Tibeto-Burman populations on the paternal side and close to Mongolic-speaking populations on the maternal side; (2) lineage comparisons at the individual level showed that the Foyemiaowan population consisted of primarily Tibeto-Burman and Han Chinese related lineages (Oα-M117, 25%;Oβ-F46, 18.75%), partially Altaic speaking North Eurasian lineages (N-F1206, 18.75%) and a slight admixture of southern East Asian lineages (O1b1a2-Page59, 6.25%; O1b1a1-PK4, 3.13%). Similarly, the maternal gene pool of Foyemiaowan contained northern East Asian (A, 4.17%; CZ, 16.67%; D, 20.83%; G, 4.17%; M9, 4.17%), southern East Asian (B, 12.51%; F, 20.83%) and western Eurasian (H, 4.17%; J, 4.17%) related lineages; (3) we discovered a relatively high genetic diversity among the Foyemiaowan population (0.891) in our ancient reference populations, indicating a complex history of population admixture. Archeological findings, stable isotope analysis and historical documents further corroborated our results. Although in this period China’s central government had relinquished control of the Hexi Corridor and regional non-Han regimes became the dominant regional power, Foyemiaowan’s inhabitants remained strongly influenced by Han culture.
Sedimentary ancient DNA has been proposed as a key methodology for reconstructing biodiversity over time. Yet, despite the concentration of Earth’s biodiversity in the tropics, this method has rarely been applied in this region. Moreover, the taphonomy of sedimentary DNA, especially in tropical environments, is poorly understood. This study elucidates challenges and opportunities of sedimentary ancient DNA approaches for reconstructing tropical biodiversity. We present shotgun-sequenced metagenomic profiles and DNA degradation patterns from multiple sediment cores from Mubwindi Swamp, located in Bwindi Impenetrable Forest (Uganda), one of the most diverse forests in Africa. We describe the taxonomic composition of the sediments covering the past 2200 years and compare the sedimentary DNA data with a comprehensive set of environmental and sedimentological parameters to unravel the conditions of DNA degradation. Consistent with the preservation of authentic ancient DNA in tropical swamp sediments, DNA concentration and mean fragment length declined exponentially with age and depth, while terminal deamination increased with age. DNA preservation patterns cannot be explained by any environmental parameter alone, but age seems to be the primary driver of DNA degradation in the swamp. Besides degradation, the presence of living microbial communities in the sediment also affects DNA quantity. Critically, 92.3% of our metagenomic data of a total 81.8 million unique, merged reads cannot be taxonomically identified due to the absence of genomic references in public databases. Of the remaining 7.7%, most of the data (93.0%) derive from Bacteria and Archaea, whereas only 0–5.8% are from Metazoa and 0–6.9% from Viridiplantae, in part due to unbalanced taxa representation in the reference data. The plant DNA record at ordinal level agrees well with local pollen data but resolves less diversity. Our animal DNA record reveals the presence of 41 native taxa (16 orders) including Afrotheria, Carnivora, and Ruminantia at Bwindi during the past 2200 years. Overall, we observe no decline in taxonomic richness with increasing age suggesting that several-thousand-year-old information on past biodiversity can be retrieved from tropical sediments. However, comprehensive genomic surveys of tropical biota need prioritization for sedimentary DNA to be a viable methodology for future tropical biodiversity studies.
Top-cited authors
Margaret Byrne
  • Department of Biodiversity, Conservation and Attractions, Western Australia
Henrik G. Smith
  • Lund University
Klaus Birkhofer
  • Brandenburg University of Technology Cottbus - Senftenberg
Maj Rundlöf
  • Lund University
Gavin Leslie Simpson
  • Aarhus University