Biodiversity inventories

Biodiversity discovery

Most species remain to be described, named or even encountered. Names are essential, since without them, we cannot tell whether we are talking about the same or different species, and what species are shared between different places. We create the tools for efficient biodiversity discovery – and apply them, too. In project Lifeplan [link], we have created the biggest sample of global biodiversity ever generated by standardised methods. These samples consist of sounds, DNA sequences and images. The main challenge is then to make sense of all the variation encountered. What variation represents technical errors, what is real? Where should we draw the limits between unknown species? How can we estimate the true number of species when any sample is too small to catch them all? For each of these challenges, we are creating new tools.

A phylogenetic framework

In making sense of DNA variation, phylogenetic placement has emerged as one of the best approaches to classify novel taxa. Here,a reference tree is used as a biological map for an individual sequence to find where it likely sits relative to the other species. Thus, even if an individual sequence is unknown, phylogenetic placement allows us to tell which group it is likely to belong to. For example, we might be able to identify a new species, which might belong to a new genus, within the family Riodinidae in butterflies. We also use this phylogenetic placement to populate the Insect Tree of Life with these newly discovered sequences and thus build an ever-growing tree to explore how biodiversity is distributed and where there are gaps in our current knowledge. Additionally, phylogenies can be used for metrics of diversity, for example as a community diversity index or for conservation purposes – by revealing how closely or distantly related the members of a given community are to each other. Because phylogenetic trees are transversal to most of our work, generating new phylogenetic resources at different geographic and taxonomic scales is key.

Ultrasound-based monitoring

Bats are invaluable to the functioning of ecosystems, yet four out of five known species remain poorly studied – largely due to monitoring challenges based on their cryptic nature. Their biodiversity can be explored through acoustic monitoring, as different species echolocate and communicate using distinct calls, many of which occur at ultrasonic frequencies beyond the range of human hearing. These soundscapes also capture insects and other nocturnal life, offering a unique window into nighttime ecosystems. By advancing automated sound analysis tools, researchers can survey bat populations more efficiently and at scale, helping to close critical gaps in global biodiversity knowledge.