Linking changes in taxon abundance to biotic and abiotic drivers over space and time is critical for understanding biodiversity responses to global change. Furthermore, deciphering temporal trends in relationships among taxa, including correlated abundance changes (e.g. synchrony), can facilitate predictions of future shifts. However, what drives these correlated changes over large scales are complex and understudied, impeding our ability to predict shifts in ecological communities. We used two global datasets containing abundance time-series (BioTIME) and biotic interactions (GloBI) to quantify correlations among yearly changes in the abundance of pairs of geographically proximal taxa (genus pairs). We used a hierarchical linear model and cross-validation to test the overall magnitude, direction and predictive accuracy of correlated abundance changes among genera at the global scale. We then tested how correlated abundance changes are influenced by latitude, biotic interactions, disturbance and time-series length while accounting for differences among studies and taxonomic categories. We found that abundance changes between genus pairs are, on average, positively correlated over time, suggesting synchrony at the global scale. Furthermore, we found that abundance changes are more positively correlated with longer time-series, with known biotic interactions and in disturbed habitats. However, the magnitude of these ecological drivers alone are relatively weak, with model predictive accuracy increasing approximately two-fold with the inclusion of study identity and taxonomic category. This suggests that while patterns in abundance correlations are shaped by ecological drivers at the global scale, these drivers have limited utility in forecasting changes in abundances among unknown taxa or in the context of future global change. Our study indicates that including taxonomy and known ecological drivers can improve predictions of biodiversity loss over large spatial and temporal scales, but also that idiosyncrasies of different studies continue to weaken our ability to make global predictions.
Species around the globe are shifting their ranges into new territories at an unprecedented rate. In particular, the spread of foundation species can transform recipient communities and ecosystems, however, the effects on belowground processes and diversity remain poorly documented. Belowground fungi are well suited for taking the ‘pulse' of changing ecosystems given their rapid turnover and implication in a wide variety of ecosystem processes. To better understand the belowground effects of range‐expanding species, we leveraged an ongoing invasion of a foundation tree species Pinus contorta into alpine tundra to study the impacts on belowground abiotic conditions and the fungal communities associating with the roots of resident plants. We found that individual range‐expanding trees create distinct abiotic ‘islands' with wetter soils and altered soil nutrients compared to the surrounding alpine tundra ecosystem. Potentially driven by these abiotic changes, we observed a decrease in the α diversity of mutualistic fungi and an increase in the α‐diversity of pathogenic fungi during later stages of range expansion. Changes in γ‐diversity mirrored patterns of α diversity while β‐diversity was only minorly affected by range‐expanding trees, suggesting that local habitat amelioration/deterioration rather than changes in among‐patch heterogeneity underpin trends in belowground diversity. In sum, our results show that range‐expanding foundation species can modify ecosystems by altering belowground abiotic conditions and diversity across scales. These impacts begin only a few years after initial range‐expansion and establishment and scale rapidly over time, indicating the need for preventative or swift conservation action to prevent long‐term consequences.
The past decade has yielded more biodiversity observations from community science than the past century of traditional scientific collection. This rapid influx of data is promising for overcoming critical biodiversity data shortfalls, but we also have vast untapped resources held in undigitized natural history collections. Yet, the ability of these undigitized collections to fill data gaps, especially compared against the constant accumulation of community science data, remains unclear. Here, we compare how well community science (iNaturalist) observations and digitized herbarium specimens represent the diversity, distributions, and modeling needs of vascular plants in Canada. We find that, despite having only a third as many records, herbarium specimens capture more taxonomic, phylogenetic, and functional diversity and more efficiently capture species’ environmental niches. As such, the digitization of Canada’s 7.3M remaining specimens has the potential to more than quintuple our ability to model biodiversity. In contrast, it would require over 27M more iNaturalist observations to produce similar benefits. Our findings indicate that digitizing Earth’s remaining herbarium specimens is likely an efficient, feasible, and potentially critical investment when it comes to improving our ability to predict and protect biodiversity into the future. Here, the authors compare the diversity of vascular plants found in community science observations and digitized herbarium specimens, finding that with only one-third the records, herbaria still capture more data by several metrics.
Global commitments to protect 30% of land by 2030 present an opportunity to combat the biodiversity crisis, but reducing extinction risk will depend on where countries expand protection. Here, we explore a range of 30x30 conservation scenarios that vary what dimension of biodiversity is prioritized (taxonomic groups, species-at-risk, biodiversity facets) and how protection is coordinated (transnational, national, or regional approaches) to test which decisions influence our ability to capture biodiversity in spatial planning. Using Canada as a model nation, we evaluate how well each scenario captures biodiversity using scalable indicators while accounting for climate change, data bias, and uncertainty. We find that only 15% of all terrestrial vertebrates, plants, and butterflies (representing only 6.6% of species-at-risk) are adequately represented in existing protected land. However, a nationally coordinated approach to 30x30 could protect 65% of all species representing 40% of all species-at-risk. How protection is coordinated has the largest impact, with regional approaches protecting up to 38% fewer species and 65% fewer species-at-risk, while the choice of biodiversity incurs much smaller trade-offs. These results demonstrate the potential of 30x30 while highlighting the critical importance of biodiversity-informed national strategies.
Phenotypic plasticity enables rapid responses to environmental change, and could facilitate range shifts in response to climate change. What drives the evolution of plasticity at range edges, and the capacity of range-edge individuals to be plastic, remain unclear. Here, we propose that accurately predicting when plasticity itself evolves or mediates adaptive evolution at expanding range edges requires integrating knowledge on the demography and evolution of edge populations. Our synthesis shows that: (i) the demography of edge populations can amplify or attenuate responses to selection for plasticity through diverse pathways, and (ii) demographic effects on plasticity are modified by the stability of range edges. Our spatially explicit synthesis for plasticity has the potential to improve predictions for range shifts with climate change.
Understanding the strength and predictability of changes in global biodiversity is critical for quantifying how taxa will respond to global change. By analyzing the relationships in population trends among taxa exposed to both biotic and abiotic pressures, we may be able to discern these patterns, potentially facilitating the formulation of predictive frameworks for their future shifts. However, the extent to which these pressures can describe changes in abundances over large spatial and temporal scales is vastly understudied. We use two global datasets containing abundance time-series (BioTIME) and biotic interactions (GloBI) to fit a series of hierarchical models testing whether the yearly change in abundance of any given genus is associated with the yearly change in abundance of another geographically proximal genus (i.e. genus pairs) within the same study. We then use posterior predictive modeling to assess the predictive accuracy for each genus pair from the modeled output. Finally, we test how associations and predictive accuracy are influenced by site latitude, GloBI interactions, disturbance, time-series length, and taxonomic classification to assess what ecological factors explain differences in associations and/or predictability. Generally, we find that abundance changes between genus pairs tend to be neutral to weakly positively associated over time and have good predictive accuracy as long as yearly changes in abundance are not exceedingly large (<=39%). Associations and predictive accuracy across genus pairs vary systematically across ecological factors and taxonomic identity, increasing with longer time-series, towards the equator, and in disturbed habitats. Our results show that global time-series data can illustrate meaningful, albeit variable, relationships between genera and that these patterns are shaped by known ecological factors. Overall, this suggests that by incorporating broad and accessible ecological information, we can improve forecast methods to mitigate biodiversity loss in an era of global change.
Yellow-headed (Xanthocephalus xanthocephalus) and red-winged (Agelaius phoeniceus) blackbirds coexist in marshes across North America. Pictured here at Iona Beach Regional Park in Vancouver, British Columbia, males of each species compete for nesting areas. In wetlands across their overlapping ranges, yellow-heads are dominant over red-wings, pushing them out of valuable marsh real-estate to secure the best nesting places. Unfortunately, since the construction of Vancouver International Airport in 1968 and its expansion in subsequent years, both species have lost substantial extents of marsh habitat. Given their dominant–subordinate relationship, one might expect that habitat loss should disproportionately impact the subordinate red-wings, since they get last choice at nesting habitat, which might limit their reproductive success. Today, however, Iona Beach supports a healthy and abundant population of red-wings, and usually hosts only a few yellow-heads. Indeed, over the past half-century, the population of yellow-heads at Iona Beach has decreased ~95%, down from an estimated 70 individuals in 1970 to only 1–3 nowadays (Campbell RW, Dawe NK, McTaggart-Cowan I, et al. 2001. The Birds of British Columbia. Volume 4. Royal British Columbia Museum Victoria. Vancouver, Canada: UBC Press). Despite their dominance, the yellow-headed blackbirds of Vancouver have seemingly been more negatively impacted by habitat loss and degradation than their subordinate red-winged cousins. Does their dominant behavior make yellow-heads more vulnerable to change? Are red-wings more tolerant of anthropogenic disturbances? Over the next decade, the potential extirpation of yellow-headed blackbirds from Iona Beach calls into question which blackbird genuinely is the dominant species. Of course, none of this stops the remaining few yellow-heads from bullying the abundant red-wings out of prime nesting space. At least population decline has not adversely impacted their yellow-headed ego!
As a fast-growing area of technology, sequencing platforms are updated frequently and this rapid technical revolution poses not only great advances but also challenges. To be effective, biomonitoring programmes need to deliver comparable results across research groups and time. Understanding the sources of bias in bioinformatics promotes reliable results that accurately reflect biodiversity. We assembled two mock communities of planktonic organisms to assess the accuracy of species recovery based on sequencing the 18S rRNA V4 region using two NGS platforms, Roche 454 (the platform of choice for early metabarcoding studies), and Illumina MiSeq (employed frequently in recent metabarcoding studies). Our findings suggest that the two platforms have comparable performance on metabarcoding datasets. When singletons (sequences represented by a single read) were excluded from analyses, Illumina MiSeq had a slightly better operational taxonomic unit (OTU) precision score than Roche 454 (calculated as the number of species detected divided by the number of OTUs generated) but only in one bioinformatics workflow (when paired reads were appended, not merged). Roche 454 performed slightly better than Illumina MiSeq in terms of species detection but only when simple mock communities with a single individual per species were analysed. When singleton sequences were included, both platforms detected more than 75% of species with a slightly higher detection achieved by Illumina MiSeq. The OTU clustering of both datasets resulted in a gross overestimation of species richness. This finding suggests that studies employing OTU clustering as a proxy for genetic diversity must carefully perform read processing, such as singleton exclusion, to avoid overestimates. Finally, this study provides insight into technical bioinformatic strategies that should accompany such transitions. In a field such as metabarcoding, where advances in sequencing technology constantly drive the discipline, ensuring the comparability of past and future technologies, and the derived ecological conclusions is important.
The advantages of MISER LC-MS (high throughput, simple readout of results) are demonstrated in the analysis of E-capsaicin in chili peppers and hot sauces. The ready availability of samples with a wide range of capsaicin content and the fast and easy detection using the MISER (Multiple Injections in a Single Experimental Run) technique makes this a potentially useful experiment to introduce novices to the important analytical technique of LC-MS. In this study we describe a simple and rapid chromatographic method for evaluation of E-capsaicin in chili peppers using HPLC with 80% organic eluent in a Poroshell SB-C18 column coupled with electrospray ionization mass spectrometry detection and MISER analysis. The misergrams obtained from continuous sample injections every 0.73 min allow the convenient simultaneous visualization of the outcomes of multiple experiments represented as single chromatograms. A considerable variation in E-capsaicin levels is clearly visualized among different types of peppers and sauces, with the ghost pepper (Bhut Jolokia) showing the highest E-capsaicin concentration of the peppers sampled.
A series of cyclophanes composed of two triarylelement caps linked by two-atom bridges has been synthesized. The bridgehead functional groups include phosphines in combination with amines, hydrosilanes, methylsilanes, and ethoxysilanes. Computational studies accurately predicted that when the bridgehead substituents are small (lone pairs or protons), an in,in bridgehead stereochemistry is strongly favored, but larger bridgehead substituents favor the formations of in,out stereoisomers. The X-ray structures, spectra, and reactivity of these compounds are discussed, as well as the resolution of one of the cyclophanes into pure enantiomers.