Project: Burning for forage and biodiversity? Long term ecological effects of large scale wild fire and prescribed burning

Last changed: 29 March 2018
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Sustainable forest management faces a number of urgent challenges, including land use conflicts between maintaining biodiversity for ecosystem functions, supporting conservation and maximizing forest production. Fire is an important disturbance in boreal forest but has been replaced with management in Fennoscandia, which have had negative effects on biodiversity. Herbivory and fire are two disturbances that often co-occur but studies of their interactions are rare in forest ecosystems and almost absent in the boreal forests of Fennoscandia.

The overarching aim with this project is to quantify the ecological long term (>10 years) effects of large scale wildfire and prescribed burnings in boreal landscapes and to evaluate how ungulate browsing, landscape characteristics and management history might impact the occurrence of saproxylic beetles, polypores and ectomycorrhizal fungi after fire. We will also evaluate the potential of burned areas to produce food for herbivores. This project constitute a unique opportunity to evaluate long term effects of large scale forest fire, including three replicates that burnt the same year and located in landscapes with a range of management intensity. The project is highly relevant for sustainable forest management because the potential synergistic effects that can be reached by combining the usefulness of a conservation measure (burning) for biodiversity conservation with damage prevention through alternative forage production.

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Photo: Therese Löfroth
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Photo: Therese Löfroth
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Photo: Therese Löfroth
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Photo: Therese Löfroth
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Photo: Therese Löfroth

Study area/study design

Replication of large natural fires is unique in the heavily managed boreal landscape of Fennoscandia. Our study areas consists of three large (300 – 1900 ha) natural fire areas in Norrbotten that all burned in 2006. In each of the burned areas, 6 study plots (3 young stands consisting mainly of trees regenerated after the fire and 3 old stands dominated by trees that survived the fires) will be selected within areas that has been left unharvested after the fire. For each of the burned areas 3 young stands and 3 old stands will be selected in similar forest types outside the burned area and function as control areas. We will also include prescribed burnings of clear-cuts and mature forest (Table 1).

Table 1. Number of replicates of the different stand types within the landscapes surrounding each natural fire. For natural fire all sampling sites in each landscape will be located within the set aside area of unharvested burned forest but in different stands and separated by at least 500 m.

The three burned areas differ in the management history of the surrounding landscape and in the dominating burned forest type. The largest fire in Bodträskfors mostly affected young and middle aged managed forest including mostly pine dominated stands [37]. The fire in Muddus was located within a large national park and affected dry pine forest mainly as a ground fire [37]. In Lainio, the fire affected 200-year old spruce forest and the high intensity of the fire resulted in crown fire with high tree mortality. The landscape surrounding the Lainio burn is dominated by spruce forest with high conservation values [37] (Table 2). The differences among these three fires give us the opportunity to test if long term effects of forest fire are general over a wide range of habitats.

Table 2. The burned areas included in the study. The study sites are all within the retained parts of the burned areas.

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