Adaptive Radiation of Aquatic MIcrobial Species (ARAMIS). The action aims to understand the causes, mechanisms and consequences of adaptive radiation (i.e. the process in which organisms diversify rapidly to occupy ecological niches) in freshwater microbial communities. This will help solve several of the outstanding questions in the field of microbial ecology, such as how shifts in environmental conditions impact the trajectory of microbial evolution, the relative importance of horizontal versus vertical gene transfer in microbial ecosystems, or the definition of microbial ‘species’. As diversity is linked with stability, elucidating the factors driving diversification in freshwater taxa will also help us predict how such ecosystems may respond to future change. ARAMIS proposes the novel hypothesis that, while every freshwater clade has a unique evolutionary history, the environmental forces driving such evolution are fundamentally the same, both in nature and in relative importance. If validated, this simple paradigm would push the state of the art and allow the development of powerful conceptual models integrating environmental constraints, microbial diversification, and community stability. The hypothesis will be tested by combining metagenomics, metatranscriptomics and enrichment cultures over a set of more than 200 lake samples. This will contribute to a conceptual synthesis between community ecology and evolutionary biology by closing the gap between theoretical work and data-driven studies. ARAMIS has a high academic potential but, since it deals with the stability of freswater microbial populations, can also have social and public policy impact by bringing an ecoevolutionary perspective to the management of aquatic resources.

While the latitudinal diversity gradient is one of the rare patterns that might be considered general and widely accepted in ecology, the latitudinal specialisation gradient remains controversial. Ecological specialisation varies greatly across the tree of life, with clades that depend on a host organism for survival being among the most specialised. Understanding the processes that produce the global pattern of increasing host specialisation with decreasing latitude would be a breakthrough in the field of evolutionary ecology. This project will investigate the causes and consequences of higher host specialisation in the tropics, focusing on fundamental repertoires (expressed and non-expressed host use abilities). First, we will test if tropical species are genetically more specialised to their hosts by identifying host-associated gene modules and reconstructing their evolution across tropical and temperate species in the tribe Nymphalini. Then, we will test if higher specialisation is an artifact of data scarcity in the tropics. For that, we will develop an efficient approach for data collection based on interaction prediction, and produce a comprehensive dataset of fundamental and realised host repertoires for tropical Melitaeini butterflies. Then, including the entire Nymphalidae family, we will test if evolution of species interactions in the tropics favours specialisation. We will apply a combination of phylogenetic and network analyses to existing global datasets (augmented with all data produced in this project) to unravel how fundamental host repertoires evolve and whether current theory is able to explain tropical interactions equally well as the better-studied temperate interactions. Finally, we will quantify the consequences of host specialisation in a changing world in terms of risk of coextinction. The frameworks developed here can be easily expanded to other symbiont-host systems, increasing the significance of this research far beyond butterflies.

Plants lack a nervous system and central decision-making organ like a brain, but can nevertheless sense and respond to environmental cues that play crucial roles in regulating their growth, through poorly understood mechanisms. The aim of DECORE is to elucidate these mechanisms, particularly those underlying the low temperature-mediated control of bud dormancy in the model tree hybrid aspen. A recent discovery in the host lab, pinpointing AGL8 as a low temperature responsive transcription factor involved in bud dormancy release, has lead us to hypothesize that AGL8-mediated transcriptional control of the plant hormone gibberellin, mobile signaling component FT1 (a tree ortholog of Arabidopsis FLOWERING LOCUS T) and cell-cell communication together orchestrate bud dormancy release. In DECORE, Dr. Pandey will test this hypothesis by deciphering the interplay between gene expression, hormonal regulation and cell-cell communication during dormancy release, and simultaneously acquire skills in cutting-edge techniques like transmission electron microscopy, immunocytochemistry and mass spectrometry in leading environments at the host SLU/UPSC (Umeå, Sweden) and via secondment to CNRS (Bordeaux, France). Synergistically complementing the skills in biochemistry and genomics gained during his PhD, this training will provide Dr. Pandey with a unique opportunity to broaden his technical and theoretical expertise, which will promote a successful achievement of the project’s goals, open new vistas in developmental adaptation, and support his ambition of becoming a research leader. Dr. Pandey will follow a personalized career development plan to enhance his skills in communication, grant writing, public engagement and student mentoring. Thus, DECORE will contribute fundamental knowledge on a key process in seasonal adaptation, critical for mitigating the effects of climate change on seasonal growth in trees, and career advancement of a scientist with outstanding potential.

Crop diversification offers substantial potential benefits for smallholder farmers in southern Africa. Positive interactions between diverse crops can lead to higher and more stable yields, more nutritious diets, better economic returns, and lower agrichemical use. However, choosing the right diversification option to realise these benefits is challenging. Interactions between crops can be negative as well as positive, and it is not yet well understood which features of different crop combinations and their environments determine their overall performance. EcoDiv will address this knowledge gap by undertaking an ambitious analysis of large datasets from agricultural field experiments across Zimbabwe, Zambia and Malawi. Specifically, EcoDiv will 1) quantify the relationships between crop combination productivity and crop traits under different environmental conditions, 2) explore which characteristics of crop combinations are important to meet different socioeconomic needs, and 3) investigate whether the effects of crop combinations on microhabitat conditions explain their performance. This research will produce an ecological framework for crop diversification in southern Africa: an understanding of the key interactions between crop traits and environmental conditions that predict the performance of different crop combinations in different contexts. To achieve EcoDiv’s objectives, Dr Chloe MacLaren (the research fellow) will work with interdisciplinary and international research teams at two host institutes, the Swedish University of Agricultural Sciences (SLU) and the International Maize and Wheat Improvement Centre (CIMMYT). EcoDiv will advance Dr MacLaren’s career by developing the knowledge, skills, and networks needed to achieve leading research positions in ecology for agricultural development. Both hosts will benefit from transfer-of-knowledge in new statistical methods, and from strengthened collaboration around shared research goals in sub-Saharan Africa.

Aboriginal societies around the world have independently transitioned their production mode. In northern Eurasia, the transition manifested itself in a movement away from transport reindeer herding towards reindeer pastoralism from the sixteenth to nineteenth centuries. Although this was one of the most significant changes affecting circumpolar people across the region, much remains unknown about the drivers of this transition, and even less about its consequences for indigenous governance and social relations. Northern Fennoscandia was one of the first regions to witness the transition, and the indigenous Sami of northern Sweden are an especially suitable case for addressing these gaps. The historical sources are exceptionally rich and Sami are a very interesting case because reindeer pastoralism developed in a foraging culture, with many households continuing as hunters and fishers even after the transition dominated society. A central assumption is that the transition to reindeer pastoralism was induced by market opportunities. TransRein builds on the hypothesis that the transition of these societies was driven by concomitant, self-governed responses as the transition progressed and will advance research about indigenous reindeer-herding societies beyond the state of the art by pursuing the following three objectives. 1. Create a detailed depiction of the transition from transport reindeer herding to reindeer pastoralism among indigenous Sami, focusing on governance of natural resources and—for the first time—its effect on social relations, and significantly deepen our understanding of indigenous governance, 1550–1800. 2. Identify common forces behind the transition through comparisons with other reindeer-herding societies in Eurasia that underwent the same transition. 3. Place the transition in two wider contexts; the transitions from foraging economies to pastoralism in other societies, and the transition in a European context of early modern agrarian change.