Nature ecology & evolution最新文献

Deuterostomes are one major group of bilaterians composed by hemichordates and echinoderms (collectively called Ambulacraria) and chordates. Comparative studies between these groups can provide valuable insights into the nature of the last common ancestor of deuterostomes and that of bilaterians. Indirect development of hemichordates, with larval phases similar to echinoderms and an adult body plan with an anteroposterior polarity like chordates and other bilaterians, makes them a suitable model for studying the molecular basis of development among deuterostomes. However, a comprehensive, quantitative catalogue of gene expression and chromatin dynamics in hemichordates is still lacking. In this study, we analysed the transcriptomes and chromatin accessibility of multiple developmental stages of the indirect-developing hemichordate Ptychodera flava. We observed that P. flava development is underpinned by a biphasic transcriptional program probably controlled by distinct genetic networks. Comparisons with other bilaterian species revealed similar transcriptional and regulatory dynamics during hemichordate gastrulation, cephalochordate neurulation and elongation stages of annelids. By means of regulatory networks analysis and functional validations by transgenesis experiments in echinoderms, we propose that gastrulation is the stage of highest molecular resemblance in deuterostomes and that much of the molecular basis of deuterostome development was probably present in the bilaterian last common ancestor.

Many terrestrial plant communities, especially forests, have been shown to lag in response to rapid climate change. Grassland communities may respond more quickly to novel climates, as they consist mostly of short-lived species, which are directly exposed to macroclimate change. Here we report the rapid response of grassland communities to climate change in the California Floristic Province. We estimated 349 vascular plant species’ climatic niches from 829,337 occurrence records, compiled 15 long-term community composition datasets from 12 observational studies and 3 global change experiments, and analysed community compositional shifts in the climate niche space. We show that communities experienced significant shifts towards species associated with warmer and drier locations at rates of 0.0216 ± 0.00592 °C yr⁻¹ (mean ± s.e.) and −3.04 ± 0.742 mm yr⁻¹, and these changes occurred at a pace similar to that of climate warming and drying. These directional shifts were consistent across observations and experiments. Our findings contrast with the lagged responses observed in communities dominated by long-lived plants and suggest greater biodiversity changes than expected in the near future.

The density of wood is a key indicator of the carbon investment strategies of trees, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here we analyse information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical forests being up to 30% denser than that in boreal forests. In both angiosperms and gymnosperms, hydrothermal conditions represented by annual mean temperature and soil moisture emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.

Accuracy and clarity in the names of species are achieved through globally agreed rules: the various international codes of nomenclature. For plants, proposed amendments to these rules¹ are debated during a week-long side meeting of the International Botanical Congress, which is held once every six years — most recently in Madrid in mid-July 2024 (ref. ²). Amendments accepted by delegates to that meeting will be included in the next published International Code of Nomenclature for Algae, Fungi, and Plants (hereafter, Code), due in 2025. Three controversial issues were considered at the 2024 International Botanical Congress, two of which focused on addressing ethical issues that arise from historical nomenclature and one of which aimed at future-proofing the type method to ensure that biological nomenclature is able to continue to accurately document and name the Earth’s biodiversity.

In the end, modest decisions were taken with respect to the first issue, which addressed eponymy — the common practice of naming taxa in honour of significant individuals. Eponyms capture and permanently record noteworthy — and sometimes troubling — aspects of the history and social context of the science of taxonomy. A set of proposals³ considered by the Madrid meeting provided a mechanism by which problematic eponyms, such as those that honour traders of enslaved persons or colonial administrators who were responsible for genocidal policies and acts, could be retired and replaced by more appropriate and acceptable names. When first published in 2021, these proposals sparked controversy: some argued that they would throw nomenclature into disarray by opening a floodgate of re-namings. By the opening of the Madrid meeting, the proposals had polarized the community. By the end of the meeting, a decision had been reached (the required 60% supermajority had been achieved) to amend the Code to allow the rejection of names that are derogatory to a group or groups of people, but only for names published after 1 January 2026. Although this decision recognizes that derogatory names are unacceptable, the meeting attendees demurred from establishing a way to deal with historical derogatory names. A special committee was established to report to the next meeting (in Cape Town, South Africa, in 2029) on how best to deal with matters of ethics in botanical nomenclature. The committee, once established, has an important but challenging remit — to find an appropriate way forward in a contested space.

replying to L. A. Muir & J. P. Botting Nature Ecology & Evolution https://doi.org/10.1038/s41559-024-02559-6 (2024)

The Cabrières Biota (France) is a new diverse fossil assemblage that provides insights into Ordovician polar ecosystems¹. This assemblage comprises fossils of algae, sponges, cnidarians, trilobites, non-biomineralized arthropods, molluscs, brachiopods, hyoliths, hemichordates, worms and lobopodians¹, as well as trace fossils. Muir and Botting² question whether the site is a Lagerstätte by reinterpreting sponges, algae, hemichordates, worms and cnidarians as trace fossils. Here we show that their arguments do not follow an evidence-based approach and the specifics of their trace fossil claims do not engage with the standard protocols for distinguishing between trace and body fossils. We provide comprehensive evidence that the Cabrières Biota is a diverse and exceptionally preserved fossil Lagerstätte including algae and animals, representing a high-latitude refugium during the warm Early Ordovician.

arising from F. Saleh et al. Nature Ecology & Evolution https://doi.org/10.1038/s41559-024-02331-w (2024)

Saleh et al.¹ announced the Cabrières Biota as a new exceptionally preserved fossil assemblage (Konservat-Lagerstätte) of Early Ordovician age dominated by sponges and algae. New deposits of this type are needed to better understand Ordovician ecology and biodiversification and the Cabrières assemblage was presented as a major advance in knowledge of Ordovician polar communities¹. However, the specimens identified as sponges, algae, a worm, a hemichordate tube and a lobopod (that is, all of the non-arthropod exceptionally preserved taxa) appear to be trace fossils, mostly burrows containing faecal pellets. Thus, the Cabrières fossils do not constitute an exceptionally preserved assemblage and the conclusions relating to polar palaeoecology cannot be supported.

The failure to halt the global decline in biodiversity by 2020 contributed to the adoption of the ambitious Kunming-Montreal Global Biodiversity Framework, which includes transparency and responsibility as foundations. The Global Biodiversity Framework identifies the actions needed so that societies are living in harmony with nature by 2050. To support the delivery of this ambition, the transparency and responsibility mechanisms defined in the Global Biodiversity Framework include a detailed Monitoring Framework designed to prompt evidence-based actions and track progress towards its goals and targets at the national and global level. The Monitoring Framework includes a set of indicators selected by the Parties through a political process. These indicators have since been operationalized through a scientific process led by an expert group focused on assessing and clarifying their methods. Most indicators are now ready to inform on progress, but key limitations of data availability and methodological challenges remain. The onus is now on the Parties to resource implementation and on the scientific community to support indicator use and development. Implementation of the Monitoring Framework will provide an unprecedented view of the state of biodiversity at the national level, which can be used to assess both national and global progress. Investment to overcome the Monitoring Framework’s weaknesses will improve our ability to measure progress and mobilize the actions needed to protect and restore biodiversity and the many benefits we receive from nature.

Rapid warming and increasing disturbances in high-latitude regions have caused extensive vegetation shifts and uncertainty in future carbon budgets. Better predictions of vegetation dynamics and functions require characterizing resilience, which indicates the capability of an ecosystem to recover from perturbations. Here, using temporal autocorrelation of remotely sensed greenness, we quantify time-varying vegetation resilience during 2000–2019 across northwestern North American Arctic-boreal ecosystems. We find that vegetation resilience significantly decreased in southern boreal forests, including forests showing greening trends, while it increased in most of the Arctic tundra. Warm and dry areas with high elevation and dense vegetation cover were among the hotspots of reduced resilience. Resilience further declined both before and after forest losses and fires, especially in southern boreal forests. These findings indicate that warming and disturbance have been altering vegetation resilience, potentially undermining the expected long-term increase of high-latitude carbon uptake under future climate.