the second half of the 20th century. Thus, studies on collections, whether paleontological, archaeological or current, seek to define and calibrate proxies to understand these changes.
Climate change research requires that these proxies be placed in the context of climate evolution over the last 20,000 to 100,000 years. In Chapter 11, Moreno and Bartolini demonstrate one such approach: the search for climate and salinity proxies in marine sediments (from a few tens of thousands of years ago to the last million years). This research is based on new collections of ocean cores, mainly from 1970 onwards. This chapter reveals the challenges inherent to the constitution and conservation, as well as to the analysis and understanding of data from such an extraordinary resource. In the same vein, Quiles et al. (Chapter 12) show how collections can provide access to atmospheric gas levels prior to a major landscape change. The aim is to calibrate the radiocarbon curve before the construction of the Aswan Dam in Egypt, which had a major impact on this region, and strongly affected the periodic flooding of the Nile. The analyses indicate that the herbarium plates of the 17th and 18th centuries allow for the detection of 14C levels in the atmosphere of this period. This study thus contributes to the refinement of archaeological dating over a historical period of several millennia, a major challenge for the knowledge of the history of ancient Egypt. These two projects reveal how collections can be at the heart of highly transdisciplinary research.
The next two chapters discuss research on the dispersal of crop pathogens and invasive alien species, problems associated with the globalization of agriculture and the transportation of diverse agricultural products over very long distances. The study by Gagnevin et al. (Chapter 13) explores the use of herbaria to study Xanthomonas citri pv. citri which infects citrus and geminiviruses that attack manioc and sweet potato. These pathogens have a strong impact on agricultural production in the Indian Ocean and sub-Saharan Africa. Their results show how new molecular and genomic methods can be used to access information residing in herbaria, rich in species of agricultural interest. These analyses make it possible to trace the origin, the evolutionary history and the dispersal routes of diseases that can have a major impact on the regional economy. The role of collections in understanding biological invasions is illustrated by Villemant et al. (Chapter 14), concerning the Asian hornet Vespa velutina, the first exotic species of Vespidae acclimatized in Europe. Their study underlines the importance of gaining data from collections in order to discover the origin of invasive lineages, the structure of diversity in its area of origin, and thus to make more accurate predictions on potential areas of invasion.
As mentioned earlier, using collections to answer targeted questions requires methodological adjustments. Sometimes the data from the collections are not sufficient to answer a question. Nevertheless, taking them into account allows us to reframe the subject and adjust the protocol. This iterative aspect, so fundamental to scientific research, is underlined well by Robuchon et al.’s study (Chapter 15). The existing data do not allow us to reach clear conclusions. However, when supplemented by targeted collections of the same species at the same locations, they can represent a solid past reference point for research on community change and local extinctions.
Despite their number, the chapters presented in this book only offer a glimpse of the diversity of research on global changes for which collections are an indispensable source of data. The review in Chapter 16 (by Muller et al.) on herbaria confirms that there is already a surprising diversity of approaches, even for this type of collection alone. The contribution of collections to understanding the effects of global change is clearly still in its infancy.
1.3.4. Designing the science of the future based on collections
As all of these examples show, collections-based research is both a user of collections to answer specific questions and a driving force of new designs for collections. The chapters in this book highlight different know-how that also enrich collections.
In Chapter 17, Garrouste reflects on the work of a naturalist, with the association of 2D, 3D and even 4D (films, movements) digital images of the collected specimens. These images make it possible to easily preserve information on living specimens (precise colors, movements, behaviors, interactions). The association of this information to specimens of collections allows us to make a conceptual leap, so much so that they are essential to ecology, physics of movements, bio-inspiration and evolution studies. Despite these advantages, the author mentions two contexts where these uses are, respectively, exacerbated and neglected, and thus their scientific potential is reduced: the use of photos as types when describing new species and the limited association of images to identifications from participatory science projects.
Today, an important part of the research on databases from natural history collections is destined to validate the data or neutralize their biases with respect to the questions asked. In Chapter 18, Monnet et al. discuss the provision and use of data via data portals or aggregators, as part of a traceability system from the collection specimen to the last of a series of users. Indeed, over the last two decades, institutions have made enormous efforts to make their data available and the number of research studies that use them is increasing exponentially. Scientific journals also play a fundamental role in recommending or requiring the availability of the data used. Nevertheless, the whole practice needs to be reviewed with rigor, and data processing and use pipelines that are more in line with principles of validation and traceability need to be built. The monitoring of the evolution of knowledge on specimens, the association of the various information obtained for the same specimen (Gene Bank Accession Number, GBIF ID, etc.), as well as that of the recovery of resampled data by other research groups are still very limited. Considering the fact that database portals and aggregators are designed to last over time and cannot be reconstructed with each new study, it is clear that new procedures must be implemented in this regard.
Questioning the collections, their values, their needs for maintenance and continuity are part of the daily life of scientists in charge of collections. This link also leads to numerous questions not only about how to add information and ensure its traceability, as proposed in the studies in Chapters 17 (Garrouste) and 18 (Monnet et al.), but also about their raison d’être and their future. Bahuchet’s study (Chapter 19) explores this issue through an analysis of biocultural collections. The basic question “do we need biocultural collections?” is posed with regard to the objects that are essential for testifying the relationship between people and nature. This question concerns all types of collections. It shows us that decisions concerning a collection cannot be taken without considering the scientific context that gave rise to their constitution.
The book concludes with a study of conservation, a research theme that is inseparable from the existence of collections. Rouchon (Chapter 20) details conservation practices and their changes over time, particularly in cases where the object to be conserved poses methodological and technical challenges. These examples reveal the magnitude of the conservation problem. How can we avoid alterations to the objects, whether they are of a physical nature, or the result of chemical reactions or biological activity? Through the question “why preserve?” the author underlines the different values that we give to collections or to certain objects, as well as the transformations that come as we gain more knowledge and understanding
