Effects of temperature and nutrient enrichment on the Arctic moss Hygrohypnella ochracea growth and productivity

• Published in: Polar Biology
• Main Authors: Manolaki, Paraskevi, Pastor, Ada, Karttunen, Krister, Guo, Kun, Riis, Tenna
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: C-CO tracer method; Aquatic primary productivity; Arctic streams; Climate change; Arctic; Greenland; Polar Biology
• Online Access: https://pure.au.dk/portal/da/publications/effects-of-temperature-and-nutrient-enrichment-on-the-arctic-moss-hygrohypnella-ochracea-growth-and-productivity(a8c0ce41-788c-46a9-aa22-de9eebd26942).html; https://doi.org/10.1007/s00300-022-03077-6; http://www.scopus.com/inward/record.url?scp=85136588355&partnerID=8YFLogxK

Arctic streams are highly sensitive to climate warming due to changes in water temperature and nutrient availability. Mosses are the dominant benthic primary producers in low-order streams in Greenland, and climate induced ecosystem alterations are expected to cause significant changes to their growth and productivity rates. However, the combined effects of climate change to stream mosses are relatively unknown. In this study, we conducted a full factorial experiment with three levels of nutrients and temperatures, and we measured primary productivity by applying the 14 C-CO 2 tracer method, relative growth rate (RGR), shoot elongation (SE) and lateral growth (length of branches, LB; Shoot density, SD). We aimed to investigate the single and interactive effect of temperature and nutrient enrichment on growth (biomass and elongation), primary productivity and shoot morphology of the Arctic aquatic moss Hygrohypnella ochracea. We found that low temperature determines H. ochracea growth however, the effect of nutrient enrichment became increasingly significant with increasing temperature. We also found important morphological changes in moss lateral growth which is expected to cause fundamental changes in moss community structure. Our results demonstrated that, in the low-order Arctic streams, climate change will cause shifts in benthic primary productivity, growth and morphology, and these changes are expected to cause cascading effects on the stream ecosystem structure, biodiversity and function.