Establishment of Cladonia stellaris after artificial dispersal in an unfenced forest in northern Sweden

In 2002, fragments and whole thalli of reindeer lichen, mainly Cladonia stellaris, were spread in a typical Scots pine forest in northern boreal Sweden to study the survival and development after artificial lichen dispersal. The forest was not fenced, allowing reindeer access to graze. Lichens were dispersed in intact vegetation in 1 m2 plots by one of two methods: either as an intact lichen mat (patch) of 0.25 m2 in the centre of the plot or as fragments scattered (scatter) across the whole plot. The lichen was then monitored by photo inventory. In 2006, three years after the first inventory, all patch plots had been partially grazed by reindeer and the lichen cover measured in both patch and scatter plots had decreased severely. In 2008, the lichen cover in the patch and scatter plots had increased by up to 54% and 88%, respectively, of the cover measured during the first inventory in 2003. A significant increase in the number of fragments in the plots was also observed between 2006 and 2008, suggesting that in addition to growing like naturally established thalli, the lichen had spread and slowly colonized the plots. Dispersing lichen by the “patch” method appears to be less costefficient than the “scatter” method, if the area is grazed by reindeer. These results support the hypothesis that dispersal of reindeer lichen could be an effective means of restoring lichen stands, which are important for reindeer husbandry, even if the area is open to reindeer grazing. Abstract in Swedish / Sammanfattning: Etablering av Cladonia stellaris efter artificiell spridning i ej inhägnad skog i norra Sverige Renlav (främst Cladonia stellaris) spreds manuellt 2002 i en talldominerad skog i norra Sverige för att studera lavens etablering efter artificiell spridning. Försöksområdet var inte hägnat utan öppet för renbete. Laven spreds i intakt markvegetation på 1 m2-ytor, antingen i form av intakta lavbålar (0,25 m2) i ytans centrum eller som fragment över hela provytan. Lavens etablering följdes med hjälp av fotoinventering. År 2006, tre år efter första inventeringen, hade alla provytor betats av ren och lavens täckningsgrad hade reducerats betydligt. Vid inventeringen 2008 hade lavens täckningsgrad ökat med upp till 54% (intakt lav) resp. 88% (lavfragment), i jämförelse med täckningsgraden den första inventeringen. Mellan 2006 och 2008 ökade antalet fragment per provyta signifikant vilket indikerar en fortsatt naturlig etablering med spridning via fragment. Att sprida lav i form av intakta lavbålar förefaller mindre kostnadseffektivt än spridning av lav i fragmentform om spridningsområdet är öppet för renbete. Resultaten utgör ett stöd för hypotesen att artificiell spridning av renlav kan vara ett effektivt sätt att restaurera viktiga renbetesområden, även om området inte är skyddat för renbete

Establishment of Cladonia stellaris after artificial dispersal in an unfenced forest in northern Sweden

In 2002, fragments and whole thalli of reindeer lichen, mainly Cladonia stellaris, were spread in a typical Scots pine forest in northern boreal Sweden to study the survival and development after artificial lichen dispersal. The forest was not fenced, allowing reindeer access to graze. Lichens were dispersed in intact vegetation in 1 m2 plots by one of two methods: either as an intact lichen mat (patch) of 0.25 m2 in the centre of the plot or as fragments scattered (scatter) across the whole plot. The lichen was then monitored by photo inventory. In 2006, three years after the first inventory, all patch plots had been partially grazed by reindeer and the lichen cover measured in both patch and scatter plots had decreased severely. In 2008, the lichen cover in the patch and scatter plots had increased by up to 54% and 88%, respectively, of the cover measured during the first inventory in 2003. A significant increase in the number of fragments in the plots was also observed between 2006 and 2008, suggesting that in addition to growing like naturally established thalli, the lichen had spread and slowly colonized the plots. Dispersing lichen by the “patch” method appears to be less costefficient than the “scatter” method, if the area is grazed by reindeer. These results support the hypothesis that dispersal of reindeer lichen could be an effective means of restoring lichen stands, which are important for reindeer husbandry, even if the area is open to reindeer grazing. Abstract in Swedish / Sammanfattning: Etablering av Cladonia stellaris efter artificiell spridning i ej inhägnad skog i norra Sverige Renlav (främst Cladonia stellaris) spreds manuellt 2002 i en talldominerad skog i norra Sverige för att studera lavens etablering efter artificiell spridning. Försöksområdet var inte hägnat utan öppet för renbete. Laven spreds i intakt markvegetation på 1 m2-ytor, antingen i form av intakta lavbålar (0,25 m2) i ytans centrum eller som fragment över hela provytan. Lavens etablering följdes med hjälp av fotoinventering. År 2006, tre år efter första inventeringen, hade alla provytor betats av ren och lavens täckningsgrad hade reducerats betydligt. Vid inventeringen 2008 hade lavens täckningsgrad ökat med upp till 54% (intakt lav) resp. 88% (lavfragment), i jämförelse med täckningsgraden den första inventeringen. Mellan 2006 och 2008 ökade antalet fragment per provyta signifikant vilket indikerar en fortsatt naturlig etablering med spridning via fragment. Att sprida lav i form av intakta lavbålar förefaller mindre kostnadseffektivt än spridning av lav i fragmentform om spridningsområdet är öppet för renbete. Resultaten utgör ett stöd för hypotesen att artificiell spridning av renlav kan vara ett effektivt sätt att restaurera viktiga renbetesområden, även om området inte är skyddat för renbete

Influence of ground substrate on establishment of reindeer lichen after artificial dispersal

Methods to improve the recovery of reindeer lichen after soil disturbance or overgrazing are being sought for areas where reindeer are herded. The effects of four substrates – mineral soil, moss, twigs and pine bark – on the establishment of lichen fragments after total removal of the vegetation were thus studied in a middle-aged pine stand and a clear-cut, both located in a lichen-rich pine-heath. Cladina mitis fragments of two sizes were manually dispersed in 1 m2 quadrats and their movements from their respective dispersal points were registered after one year. The natural re-establishment of lichens in the quadrats was monitored over three years by using digital pictures. In the forest stand, no significant differences were detected in either the fragment movement or the lichen establishment between the different substrates, but the fragment size had positive effects on both parameters. In the clear-cut, the moss substrate was the most suitable not only for the artificially dispersed lichens to fasten to, but also for the natural settlement of lichens from the surrounding lichen mat. More lichen thalli fastened to the bark and twigs substrates than to the mineral soil, but the settlement of lichens from the surrounding was greater on bare mineral soil substrate. The results indicate that artificial dispersal of lichen thalli on an appropriate substrate could be a successful strategy for promoting lichen recovery

The origins of prescribed burning in Scandinavian forestry: the seminal role of Joel Wretlind in the management of fire-dependent forests

In Sweden, prescribed burning was trialed as early as the 1890s for forest regeneration purposes. However, the origins of prescribed burning in Sweden are commonly attributed to Joel Efraim Wretlind, forest manager in the State Forest district of Mala, Vasterbotten County, from 1920 to 1952. To more fully understand the role he played in the development of prescribed burning and the extent of his burning, we examined historical records from the State Forest Company's archive and Wretlind's personal archive. The data showed that at least 11,208 ha was burned through prescribed burning between 1921 and 1970, representing 18.7% of the Mala state-owned forest area. Wretlind thus created a new forestry-driven fire regime, reaching, during peak years, extents close to historical fire regimes before the fire suppression era, and much higher than present-day burning. His use of prescribed fire to regenerate forests served as a guide for many other forest managers, spreading to all of northern Sweden during the 1950-1960s. Our analysis of Wretlind's latest accounts also shows how he stood against the evolutions of modern forestry to defend a forestry system based on the reproduction of natural processes, such as fire

Culturally modified trees and forest structure at a Kawesqar ancient settlement at Rio Batchelor, western Patagonia

Indigenous land use occurring on temporal scales over centuries or millennia shapes forests in specific ways and influences the dynamics of forest ecosystems. It is challenging to study such land use, but analysis of "culturally modified trees" (CMTs) can give precise spatial and temporal information on past land use by indigenous people. The aim of this study was to increase our knowledge of indigenous use of land and resources in Nothofagus forests by identifying CMTs and analyzing the forest structure dynamics in an ancient Kawesqar settlement site in western Patagonia. Our results show that there are CMTs at Rio Batchelor and that the forest structure varies significantly within the site, indicating that Kawesqar people altered the forest by extracting various resources. We conclude that CMT studies have great potential in Nothofagus forests in southernmost America, but also face specific challenges due to environmental conditions and lack of corroborating historical information

Managing reindeer lichen during forest regeneration procedures

In northern Sweden, conventional forest regeneration procedures applied in modern commercial forestry can disturb terricolous lichen (Cladina spp.) pastures. This has become a source of conflicts with Sámi reindeer herders. The overall aim of this thesis was to investigate forest regeneration strategies that may minimise the disturbance to, and promote the regeneration of, reindeer lichen pastures. The Sámi herders’ practices and knowledge related to the lichen resources were also analysed. Effects of gentle soil preparation methods on the re-establishment of lichen cover, reindeer grazing and establishment of Pinus sylvestris planted seedlings were studied in a field experiment. Using the HuMinMix-technique to mix the lichen mat with humus and mineral soil (humix-substrate), was found to promote lichen mat recovery more effectively than conventional scarification. Seedling establishment was highest for mounding and tracks with mineral soil. Rates of seedlings mechanically damaged, possibly caused by reindeer trampling in winter, indicates that planting on densely grazed areas should be avoided to minimize sources of conflict and to prefer either direct seeding or natural regeneration instead. According to a survey, complete re-establishment of the lichen mat after soil preparation was estimated to take about one decade on humix-substrate, compared to probably more than five decades following conventional harrowing. Possibilities for artificial dispersal of reindeer lichen, e.g. in areas disturbed by conventional soil preparation, were also studied. The substrate was identified as a key factor for lichen establishment. In this regard, mineral soil was identified as a poor substrate for reindeer lichen immobilization, while milled organic materials, such as moss, were suitable substrates for lichen immobilization and growth. All dispersal methods tested resulted in lichen establishment, but transplanted lichen cushions were heavily depleted by reindeer grazing, while fragmented lichen thalli were much less affected. A study based on ethnolinguistics demonstrated that whereas the Western use of the word ‘pasture’ is often associated with a specific plant community, Sámi herders’ understanding of the word (guohtun in Sámi) also incorporates the effect of snow on grazing. Sámi herders use their knowledge of the effects of forest trees and other vegetation on snow conditions, to strategically plan reindeer grazing during winter. Sámi herders’ knowledge of winter pastures should therefore be integrated with information on the effects of forest regeneration procedures on stand development to develop strategies that meet the needs of both commercial forestry and the reindeer herders

Sami herders’ classification system of reindeer winter pastures – A contribution to adapt forest management to reindeer herding in northern Sweden

International audienc

La gestion des pâtures de lichen au cours de la régénération forestière: Associer les savoirs locaux des éleveurs de rennes Sami et la sylviculture

In northern Sweden, conventional forest regeneration procedures applied in modern commercial forestry can disturb terricolous lichen (Cladina spp.) pastures. This has become a source of conflicts with Sámi reindeer herders. The overall aim of this thesis was to investigate forest regeneration strategies that may minimise the disturbance to, and promote the regeneration of, reindeer lichen pastures. The Sámi herders' practices and knowledge related to the lichen resources were also analysed. Effects of gentle soil preparation methods on the re-establishment of lichen cover, reindeer grazing and establishment of Pinus sylvestris planted seedlings were studied in a field experiment. Using the HuMinMix-technique to mix the lichen mat with humus and mineral soil (humix-substrate), was found to promote lichen mat recovery more effectively than conventional scarification. Seedling establishment was highest for mounding and tracks with mineral soil. Rates of seedlings mechanically damaged, possibly caused by reindeer trampling in winter, indicates that planting on densely grazed areas should be avoided to minimize sources of conflict and to prefer either direct seeding or natural regeneration instead. According to a survey, complete re-establishment of the lichen mat after soil preparation was estimated to take about one decade on humix-substrate, compared to probably more than five decades following conventional harrowing. Possibilities for artificial dispersal of reindeer lichen, e.g. in areas disturbed by conventional soil preparation, were also studied. The substrate was identified as a key factor for lichen establishment. In this regard, mineral soil was identified as a poor substrate for reindeer lichen immobilization, while milled organic materials, such as moss, were suitable substrates for lichen immobilization and growth. All dispersal methods tested resulted in lichen establishment, but transplanted lichen cushions were heavily depleted by reindeer grazing, while fragmented lichen thalli were much less affected. A study based on ethnolinguistics demonstrated that whereas the Western use of the word ‘pasture' is often associated with a specific plant community, Sámi herders' understanding of the word (guohtun in Sámi) also incorporates the effect of snow on grazing. Sámi herders use their knowledge of the effects of forest trees and other vegetation on snow conditions, to strategically plan reindeer grazing during winter. Sámi herders' knowledge of winter pastures should therefore be integrated with information on the effects of forest regeneration procedures on stand development to develop strategies that meet the needs of both commercial forestry and the reindeer herders.En Suède boréale, les techniques de régénération forestière utilisées par la foresterie moderne, notamment les préparations de sols précédant la plantation, endommagent les pâtures de lichen terricoles (Cladina spp.), et sont devenues une source de conflit entre forestiers et éleveurs de rennes Sami. L'objet de cette thèse est d'étudier des stratégies de régénération forestière pouvant réduire les perturbations et promouvoir le ré-établissement du lichen des rennes. Les savoirs et les pratiques des éleveurs Sami sur la ressource en lichen sont également analysés. Les effets de préparations de sol moins perturbatrices sur le ré-établissement du tapis de lichen, le pâturage des rennes et l'établissement de plants de Pinus sylvestris furent étudiés. L'utilisation de l'HuMinMix, technique mélangeant le couvert de lichen avec la couche d'humus et le sol minéral, est favorable à la régénération du tapis de lichen par comparaison aux préparations de sols conventionnelles. Cependant, l'établissement des jeunes pins est supérieur suivant une préparation exposant seulement le sol minéral. L'occurrence de dégâts mécaniques, possiblement causés par le piétinement des rennes, est un argument pour éviter la plantation dans les parcelles fortement fréquentées par les rennes, au profit de la régénération naturelle ou de l'ensemencement afin d'éviter les conflits avec les propriétaires forestiers. La régénération complète du tapis de lichen suivant la préparation de sol HuMinMix est estimée à une dizaine d'année comparé à plus de cinquante ans suivant les techniques conventionnelles. Les possibilités de dispersion artificielle du lichen, par exemple dans des parcelles fortement endommagées par les préparations de sol, sont également étudiées. La nature du substrat s'avère être un facteur clé pour l'établissement du lichen dispersé. Le sol minéral se révèle être un substrat ne permettant pas l'immobilisation des fragments de lichen, alors que les substrats organiques sont favorables à l'établissement et à la croissance du lichen. Au cours du suivi de 17 parcelles en régénération, toutes les espèces du genre Cladina furent observées colonisant naturellement les sols scarifiés. Néanmois la présence d'espèces de lichen pionnières semble favoriser l'établissement des lichens du genre Cladina. Toutes les méthodes de dispersion testées résultèrent en un établissement effectif du lichen. Néanmoins l'établissement suivant la transplantation de thalles lichéniques entiers, non-fragmentés, fût sévèrement réduit par le pâturage des rennes, alors que l'établissement à partir de thalles fragmentés le fût beaucoup moins. Une étude ethnolinguistique permit également de démontrer que, contrairement à son usage dans la culture occidentale où le mot ‘pâture' est associé à une communauté végétale spécifique, l'usage par les éleveurs Sami du même mot (guohtun en Sami) inclut l'effet de la neige sur les pâtures de lichen et leur pâturage par les rennes. Les éleveurs de rennes Samis utilisent leurs savoirs sur l'influence de la végétation forestière sur les conditions de neige, et donc les conditions de pâturage, pour élaborer des stratégies de pâturage au cours de l'hiver. C'est pourquoi il est nécessaire d'intégrer le savoir des éleveurs Sami sur les pâturages hivernaux en tenant compte des conséquences de la régénération forestière sur le développement et la structure du peuplement, afin d'améliorer la compréhension des effets de la production forestière sur le pâturage hivernal des rennes, et pour développer des stratégies qui satisfassent les gestionnaires forestiers et les éleveurs de rennes