Sedimentary ancient DNA shows terrestrial plant richness continuously increased over the Holocene in northern Fennoscandia.

The effects of climate change on species richness are debated but can be informed by the past. Here, we generated a sedimentary ancient DNA dataset covering 10 lakes and applied novel methods for data harmonization. We assessed the impact of Holocene climate changes and nutrients on terrestrial plant richness in northern Fennoscandia. We find that richness increased steeply during the rapidly warming Early Holocene. In contrast to findings from most pollen studies, we show that richness continued to increase thereafter, although the climate was stable, with richness and the regional species pool only stabilizing during the past three millennia. Furthermore, overall increases in richness were greater in catchments with higher soil nutrient availability. We suggest that richness will increase with ongoing warming, especially at localities with high nutrient availability and assuming that human activity remains low in the region, although lags of millennia may be expected.

Fern rhizomes as fodder in Norway.

BACKGROUND: Although ferns are often known under collective names in Norway, e.g. blom, a substantial number of vernacular names for individual fern species are known, in particular for useful or poisonous taxa. In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition's core area is found in the two North Norwegian counties of Nordland and Troms, in accordance with the longer winters encountered in the north, frequently leading to fodder shortage in early spring. The tradition extends northeastwards into Finnmark, but is less well documented there. Although numerous sources mention the use of fern rhizomes for fodder, the fern species hiding behind the tradition are incompletely known. This paper aims at reviewing available data in terms of identifyng the species used for fodder, the history and geographical distribution of such use, and other relevant traditions, e.g. the timing and mode of collection, and the way the rhizomes were used. METHODS: The study is based on data extracted from a variety of archival and literature sources; the latter retrived from my database of more than 7500 publications providing information on plant names and plant uses in Norway. RESULTS: More than 200 individual records mention the use of fern rhizomes for fodder in Norway. Only a fraction of these, typically made by botanist recording data on plant uses, provides information on the identity of the species used. Based on these, Dryopteris filix-mas and Matteuccia struthiopteris stand out as the most important species serving as sources of fern rhizomes for fodder. Locally, Dryopteris expansa was the preferred species, and this taxon may to some extent be overlooked in the records so far available. With a few exceptions, Norwegian folk tradition singles out Athyrium filix-femina as a harmful and poisonous species, causing livestock to go blind and lame, but whether this is true or not, remains unknown; the symptoms are in fact documented elsewhere as a consequence of poisoning due to Dryopteris filix-mas. In coastal north Norway, fern rhizomes were regularly collected for fodder, both in late autumn and early spring, and used to remedy a recurrent shortage of fodder in late winter and spring. Locally, the tradition of collecting fern rhizomes lived on until the 1940's or 1950's. Although mainly a tradition of the ethnic Norwegians, it had also been adopted by the farmers belonging to the Finnish and Sámi ethnic minorities. CONCLUSION: Fern rhizomes have a long tradition as an additional fodder for livestock in Norway. Preferred species were Matteuccia struthiopteris and Dryopteris filix-mas, locally also Dryopteris expansa. Athyrium filix-femina was considered to be poisonous, and usually avoided.

Scented grasses in Norway--identity and uses.

BACKGROUND: Some grass species are richer in coumarin and thus more sweetly scented than others. These have been eagerly sought after in parts of Norway, but the tradition has been weakly documented, both in terms of the species collected, their vernacular names, and uses. METHODS: Based on literature data and a substantial body of information collected during my own ethnobotanical field work, artefacts and voucher specimens, the grass species are identified, and their uses clarified. RESULTS: In Norwegian literature, the tradition of collecting and using scented grasses has received little attention, and past authors largely refer it to Anthoxanthum spp. The tradition's concentration to the Sámi strongholds of northernmost Norway, and most authors' lacking knowledge of the Sámi language, have contributed to the weak and misleading coverage in previous publications. Coumarin-rich grass species are well known in folk tradition in northernmost Norway, as luktegress (Norwegian, "scent grass"), háissasuoidni (North Sámi, "scent grass"), hajuheinä (Finnish, "scent grass"), or similar terms. They have been (and still are) frequently collected, and used as perfume, for storing with clothes, and a number of other purposes. Despite literature records identifying the species used as Anthoxanthum odoratum coll. (including A. nipponicum), the main source utilized in North Norway is Hierochloë odorata, both ssp. arctica and ssp. odorata. Anthoxanthum nipponicum and Milium effusum are alternative, but infrequently used sources of material, depending on local tradition and availability. CONCLUSION: By far the most important grass species hiding behind the "scented grass" tradition in Norway is Hierochloë odorata. Anthoxanthum nipponicum is also used, but much less frequently, and only a single record confirms the use of Milium effusum. Only the foliage of Hierochloë provides suitable material for making traditional braids. The three major ethnic groups in Norway have all utilized scented grasses as perfume and for storing with clothes, but the tradition's geographical concentration to the far north of Norway (Finnmark and NE Troms), suggests that it has originally mainly been a Sámi tradition, adopted by their neighbours.

Plant species introduced by foreigners according to folk tradition in Norway and some other European countries: xenophobic tales or not?

BACKGROUND: In their quest to understand and interpret nature, people have frequently sought religious or divine origins for plant species and their characteristics. Less often, historical events or persons are involved. This study comprises eleven cases of the latter kind, all claiming that plant species have been introduced by foreigners or at least from foreign lands. METHODS: Based on literature data and a few cases recorded during my own ethnobotanical field work, eleven European examples of pseudo-historical plant origins are presented here, including Cakile maritima, Cicuta virosa, Lathyrus japonicus, Leymus arenarius, Primula vulgaris, and Scopolia carniolica in Norway, Heracleum mantegazzianum and/or H. persicum in Denmark, Phoenix dactylifera and P. theophrastii in Greece, and Jacobaea vulgaris in Scotland. RESULTS: The only common trait in these stories is that foreigner or at least foreign lands are claimed as sources of the plant species. In most cases, the "historical" explanations given in folk tradition are demonstrably at odds with reality. In those cases that involve poisonous or potentially harmful species (Cicuta virosa, Heracleum mantegazzianum and/or H. persicum, Jacobaea vulgaris), or the "useless" Phoenix theophrastii, with its inedible fruits, the stories may be interpreted as xenophobic, blaming foreigners for introducing dangerous or worthless species. The remaining examples merely suggest a search for exotic and seemingly rational, if erroneous, origins for plant species and stands that people considered strange and unusual. CONCLUSION: The spreading vectors assumed in folk tradition are correct and well documented, e.g. ship cargos (including goods and packing materials), which are responsible for introducing ballast plants and other anthropochores, and wartime activities, introducing a broad range of species (polemochores). They do not, however, apply to the species included in this study, which are either indigenous plants or introduced ornamentals. The foreigners appearing in the folk tales serve mostly as suitably exotic explanations for what is perceived "alien" plants.

Ethnobotany of Heracleum persicum Desf. ex Fisch., an invasive species in Norway, or how plant names, uses, and other traditions evolve.

BACKGROUND: Heracleum persicum was introduced to Norway as an ornamental in the 1830's. Towards the end of the 19th century, it started spreading outside gardens, later to become a frequent sight in the major towns and settlements of North Norway - and a veritable pest plant. During the last 100 years or so, a substantial ethnobotanical tradition related to the species has evolved, demonstrating that folk knowledge is not only forgotten and lost, but also charting new terrain. METHODS: This survey is based on data extracted from all relevant publications, including botanical literature, travel accounts, newspaper notes, etc., as far as they have come to my attention. In addition, information on vernacular names and various uses of the H. persicum in Norway has been extracted from my own, substantial archive of interviews, questionnaires, and correspondence related to the ethnobotany of Norway. RESULTS: Where extant, H. persicum tends to be known to everyone, even by city dwellers who otherwise generally neglect plants. People tend to love or hate it, and in Tromsø, the largest town of northern Norway, the species has become more or less emblematic of the city. Both here and in other areas of northern Norway, it is referred to by a variety of vernacular names, partly borrowed from other species, partly derived from the Latin genus name, and partly coined for this species only. In the latter group, tromsøpalme ('the palm of Tromsø') has proved by far the most popular invention. It was seemingly first used (and coined) by German soldiers during the World War II occupation of Norway, but now largely replaces other vernacular names. The plant is still popular with children, who frequently play in and with it, whereas adults have been more prone to speculate on its origins - and how to get rid of it. Salt is the most popular "herbicide" for this purpose. CONCLUSIONS: Over the years, H. persicum has accumulated at least twenty different vernacular names in Norway, and a variety of other traditions. By necessity, all these traditions are less than 180 years old, showing that even modern and urban societies may produce a substantial body of plant lore, which certainly merits ethnobotanical attention.