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Sámi reindeer herders' perspective on herbivory of subarctic mountain birch forests by geometrid moths and reindeer: a case study from northernmost Finland.

Vuojala-Magga T, Turunen MT - Springerplus (2015)

Bottom Line: Earlier studies have shown that reindeer have a negative effect on the regeneration of defoliated birches by grazing and browsing their seedlings and sprouts.Eventually reindeer became key constructors, together with moth larvae, leading to negative ecological inheritance that forced herders to use new, adaptive herding practices.Both the scientific data and the IK of herders highlight the roles of reindeer and herders as continuous key constructors of the focal niche, one which stands to be modified in more heterogenic ways than earlier due to global warming and hence will result in new ecological inheritance.

View Article: PubMed Central - PubMed

Affiliation: Arctic Centre, University of Lapland, POB 122, FI-96101 Rovaniemi, Finland.

ABSTRACT

Introduction: Geometrid moths and semi-domesticated reindeer are both herbivores which feed on birch leaves in the subarctic mountain birch forests in northern Fennoscandia. The caterpillars of autumnal and winter moths have episodic outbreaks, which can occasionally lead to extensive defoliation of birch forests. Earlier studies have shown that reindeer have a negative effect on the regeneration of defoliated birches by grazing and browsing their seedlings and sprouts.

Case description: We interviewed 15 reindeer herders in the Kaldoaivi and Paistunturi herding co-operative in northernmost Finland in order to analyse their past, present and future views on the behaviour of moths and the growth of mountain birches. We investigate the behaviour of the two herbivores by combining the indigenous knowledge (IK) of Sámi herders with the results of relevant studies in biology and anthropology, applying niche construction theory (NCT) in doing so.

Discussion and evaluation: In the first stage, the niche constructors (moths, reindeer, herders, mountain birch and other organisms) are looked upon as "equal constructors" of a shared niche. As changes unfold in their niche, their role changes from that of constructor to key constructor. The role and importance of niche constructors were different when nomadic pasture rotation was used than they are today under the herding co-operative system. Niche construction faced its most radical and permanent negative changes during the border closures that took place over the latter half of the 19(th) century. The large-scale nomadic life among the Sámi herders, who migrated between Finland and Norway, came to an end. This phase was followed by stationary herding, which diminished the possibilities of reindeer to look for various environmental affordances. Difficult snow conditions or birch defoliation caused by moth outbreaks made the situation worse than before. Eventually reindeer became key constructors, together with moth larvae, leading to negative ecological inheritance that forced herders to use new, adaptive herding practices.

Conclusions: Both the scientific data and the IK of herders highlight the roles of reindeer and herders as continuous key constructors of the focal niche, one which stands to be modified in more heterogenic ways than earlier due to global warming and hence will result in new ecological inheritance.

No MeSH data available.


Number of days with minimum temperature below −36°C at Kevo, Finland (FMI2013).
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Fig3: Number of days with minimum temperature below −36°C at Kevo, Finland (FMI2013).

Mentions: It is predicted that the combined occurrence of mass outbreaks of autumnal moths and a new invasive species of winter moth will be more frequent, because milder winters will increase the survival rate of moth eggs (Neuvonen et al. 1999; Ayres and Lombardero 2000; Logan et al. 2003; den Herder et al. 2008; Klemola 2009; Ammunét 2011, Ammunét et al. 2012). For example, at Kevo, in northernmost Finland, the number of days with a minimum temperature below −36°C (critical for egg survival) decreased during the period 1962–2013 (FMI 2013) (Figure 3). The winter moth has already now expanded its range to continental areas of northern Finland (Jepsen et al. 2008; Klemola 2009; Karlsen et al. 2013). In the years 2006–2008 (2009) the destruction of birch forest in the Nuorgam and Polmak areas of Utsjoki was caused by winter moths. It was a new experience for herders: “I went to catch whitefish with my cousin. I was driving in front of him, and I stopped, and asked, ‘Can you see … that the ground and soil are alive?’ There were these balls the size of a human fist – worms stuck together – awful balls full of life; they were greenish worms and just full of life. They had just eaten all the birches, and it was (as late as) September (M2).Figure 3


Sámi reindeer herders' perspective on herbivory of subarctic mountain birch forests by geometrid moths and reindeer: a case study from northernmost Finland.

Vuojala-Magga T, Turunen MT - Springerplus (2015)

Number of days with minimum temperature below −36°C at Kevo, Finland (FMI2013).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4374085&req=5

Fig3: Number of days with minimum temperature below −36°C at Kevo, Finland (FMI2013).
Mentions: It is predicted that the combined occurrence of mass outbreaks of autumnal moths and a new invasive species of winter moth will be more frequent, because milder winters will increase the survival rate of moth eggs (Neuvonen et al. 1999; Ayres and Lombardero 2000; Logan et al. 2003; den Herder et al. 2008; Klemola 2009; Ammunét 2011, Ammunét et al. 2012). For example, at Kevo, in northernmost Finland, the number of days with a minimum temperature below −36°C (critical for egg survival) decreased during the period 1962–2013 (FMI 2013) (Figure 3). The winter moth has already now expanded its range to continental areas of northern Finland (Jepsen et al. 2008; Klemola 2009; Karlsen et al. 2013). In the years 2006–2008 (2009) the destruction of birch forest in the Nuorgam and Polmak areas of Utsjoki was caused by winter moths. It was a new experience for herders: “I went to catch whitefish with my cousin. I was driving in front of him, and I stopped, and asked, ‘Can you see … that the ground and soil are alive?’ There were these balls the size of a human fist – worms stuck together – awful balls full of life; they were greenish worms and just full of life. They had just eaten all the birches, and it was (as late as) September (M2).Figure 3

Bottom Line: Earlier studies have shown that reindeer have a negative effect on the regeneration of defoliated birches by grazing and browsing their seedlings and sprouts.Eventually reindeer became key constructors, together with moth larvae, leading to negative ecological inheritance that forced herders to use new, adaptive herding practices.Both the scientific data and the IK of herders highlight the roles of reindeer and herders as continuous key constructors of the focal niche, one which stands to be modified in more heterogenic ways than earlier due to global warming and hence will result in new ecological inheritance.

View Article: PubMed Central - PubMed

Affiliation: Arctic Centre, University of Lapland, POB 122, FI-96101 Rovaniemi, Finland.

ABSTRACT

Introduction: Geometrid moths and semi-domesticated reindeer are both herbivores which feed on birch leaves in the subarctic mountain birch forests in northern Fennoscandia. The caterpillars of autumnal and winter moths have episodic outbreaks, which can occasionally lead to extensive defoliation of birch forests. Earlier studies have shown that reindeer have a negative effect on the regeneration of defoliated birches by grazing and browsing their seedlings and sprouts.

Case description: We interviewed 15 reindeer herders in the Kaldoaivi and Paistunturi herding co-operative in northernmost Finland in order to analyse their past, present and future views on the behaviour of moths and the growth of mountain birches. We investigate the behaviour of the two herbivores by combining the indigenous knowledge (IK) of Sámi herders with the results of relevant studies in biology and anthropology, applying niche construction theory (NCT) in doing so.

Discussion and evaluation: In the first stage, the niche constructors (moths, reindeer, herders, mountain birch and other organisms) are looked upon as "equal constructors" of a shared niche. As changes unfold in their niche, their role changes from that of constructor to key constructor. The role and importance of niche constructors were different when nomadic pasture rotation was used than they are today under the herding co-operative system. Niche construction faced its most radical and permanent negative changes during the border closures that took place over the latter half of the 19(th) century. The large-scale nomadic life among the Sámi herders, who migrated between Finland and Norway, came to an end. This phase was followed by stationary herding, which diminished the possibilities of reindeer to look for various environmental affordances. Difficult snow conditions or birch defoliation caused by moth outbreaks made the situation worse than before. Eventually reindeer became key constructors, together with moth larvae, leading to negative ecological inheritance that forced herders to use new, adaptive herding practices.

Conclusions: Both the scientific data and the IK of herders highlight the roles of reindeer and herders as continuous key constructors of the focal niche, one which stands to be modified in more heterogenic ways than earlier due to global warming and hence will result in new ecological inheritance.

No MeSH data available.