MosSsoup

Mosses usually keep a low profile, quietly covering rocks and forest floors. But the Splachnaceae family takes a bolder approach—they grow on dung and carcasses and trick flies into spreading their spores. Instead of relying on wind, like most bryophytes, they use smell and color to lure those flies (Marino, Raguso, & Goffinet, 2009). Splachnum sphaericum,  ©Johannes Merz

I recently had the opportunity to visit Jiesnnalvárri again—this time in March, a stark contrast to my visit in August 2023. The subarctic tundra around the Kevo Subarctic Research Institute offers a unique glimpse into the extreme seasonal changes that shape plant life. In just a few months, the landscape transforms from green mountain birch forest and open  shrub and lichen dominated tundra to a frozen, snow-covered expanse. Winter: Snow and Ice In March, the tundra was completely covered in snow and ice. While it may seem like an inhospitable environment, this snow plays a crucial role in protecting the plants beneath. Snow acts as an insulator, preventing the soil from reaching extreme subzero temperatures (Bokhorst et al., 2017; Christiansen et al., 2018). For mosses and other tundra plants, this insulating effect can mean the difference between survival and death. Deeper snow cover improves plant survival rates by shielding them from harsh freezing conditions (Bokhorst et al....

Deep in the southeast of La Réunion , a tropical island shaped by its volcanos, lies the Forêt de Mare Longue —one of the last remaining lowland rainforests of the Mascarene Islands. This forest is a hotspot for endemic diversity in the archipelago. Among them is a tiny liverwort: Capillolejeunea mascarena Lejeuneaceae, a large group The genus  Capillolejeunea  is the only  Lejeuneacae  endemic to Africa (Pócs et al., 2011). Lejeuneaceae are a large group of leafy liverworts  that dominates the moist tropics with hundreds of species. Capillolejeunea mascarena  is restricted to the Comoros, Madagascar, Mauritius and Réunion.    It grows on rotting wood, corticolous and epiphyllous in lowland and submontane (100-800 m) forests.  It forms delicate mats of overlapping, bilobed leaves just a few millimeters wide.  I encountered it growing on  Agarista buxifolia , one of the native   tree species occuring only on Réuion and Ma...

In the far north of Finnish Lapland, where the boreal forest thins and open tundra begins, lie rare and fragile landforms shaped by ice: palsa mires . These wetlands are found only in areas of discontinuous permafrost, and they are among the most sensitive ecosystems in the world to climate change (Lindholm et al. 2005, Palmer et al. 2012, Fronzek et al. 2006). On a field excursion in October 2023, I visited the Skalluvaara palsa mire , located about 6 km northwest of Stuorra Skállovárri, at around 280 meters above sea level. Here, the aapa mire where open fens, sedge-dominated lawns, and low ridges form a mosaic across the subarctic landscape ends and the Palsa zone starts. Palsas are the northernmost complex mire type — unusual, elevated peat mounds that owe their existence to ice (Sollid et al. 1998, Lindholm et al. 2005) View into the palsa mire from the top of a pasla hill, palsa hill vegetation can be seen in the foreground What is a palsa? A palsa is a peat-covered hill, of...