Recent funding for VOLT
Recently, two VOLT members from the Ecosystem Ecology group, Kathrin Rousk and Mingye Yuan, have received grants for more studies on moss-cyanobacteria interactions.
Kathrin has received DKK 2,384,988 from the Villum Foundation for a project titled “The symbiotic trinity – the next step in evolution? EvoMoss”, and Mingyue was awarded SEK 4,000,500 from Vetenskapsrådet (Swedish Research Council) for a project titled “How do moss-cyanobacteria associations drive nitrogen availability and community assembly during ecosystem succession?”. You can read a summary of each project below. Congratulations, Kathrin and Mingyue!
The symbiotic trinity – the next step in evolution?
Endosymbiosis, the process where one organism engulfs another, has played a key role in the evolution of life on Earth. One of the most significant examples is the origin of plants: a free-living cyanobacterium was engulfed by a host cell, eventually evolving into the chloroplast, the photosynthesizing organelle in plant cells. Last year, a groundbreaking discovery identified another potential endosymbiosis event: a free-living, nitrogen (N)-fixing cyanobacterium was engulfed by a marine alga, forming the marine nitroplast. This new organelle supplies the host with newly fixed N, a key nutrient for all life. I propose here that we are at the dawn of a terrestrial nitroplost in moss-cyanobacteria symbioses, which can serve as a unique model system to unravel the evolution of an N-fixing organelle. Just as mitochondria and chloroplasts originated from ancient endosymbiotic events, the discovery of a terrestrial nitroplast would complete the “symbiotic trinity”, marking the third organelle acquired by plants.
How do moss-cyanobacteria associations drive nitrogen availability and community assembly during ecosystem succession?
Primary succession occurs after severe disturbances that leave ecosystems devoid of most life. For life to establish, a supply of nutrients, in particular nitrogen (N), is required. Mosses are pioneers during primary succession, and all mosses host N-fixing cyanobacteria that can provide the needed N via biological nitrogen fixation. However, no study has yet resolved the dynamics of moss-cyanobacteria associations and their contribution to ecosystem N budget during primary succession, despite its importance for ecosystem development. I will fill this key knowledge gap in ecosystem ecology by 1) determining changes in moss-cyanobacteria associations in regard to species diversity and community composition of both partners as well as field cover along a successional gradient formed from glacier advances, 2) quantifying biological N fixation during primary succession in situ using isotope tracking; 3) elucidating the interactions between moss-cyanobacteria associations and vascular plants during primary succession using Grimes’ competitive-stress-ruderal (CSR) theory, uniquely applied to mosses. This project will uncover how ecosystems develop after severe disturbance and will elucidate the contribution of N fixation to ecosystem N cycling.
