Biodiversity offsets: can we push the threshold for offsetable impacts by translocation of substrates and species?

Last changed: 29 March 2018

Land-use have led to changes in ecosystem structures and processes, biodiversity loss, and declines in ecosystem services. However, biodiversity offsetting aimed at compensating (achieving no net loss of biodiversity) for residual adverse biodiversity impacts arising from land-use projects potentially provides an approach that links biodiversity conservation and human development. However, in Sweden, biodiversity offsetting has had limited use so far, although various forms of ecological restoration have been used. There are expectations that an increased use of biodiversity offsets in Sweden could help reduce biodiversity loss and help maintain ecosystem function.

Aim

To fulfill these expectations we need to increase our understanding and knowledge regarding biodiversity offsets both from a theoretical and practical perspective. In this project (the Aitik biodiversity offset project) we will address three main topics 1) Method development: We will evaluate a novel methods for biodiversity offset, translocation of dead wood, which potentially could push the threshold for offsetable impacts and technical solutions feasible for this novel method. 2) Currency (methods for quantifying damage): We will assess how the choice of currency (metrics to estimate biodiversity) influence biodiversity offset planning and performance.  3) Robustness of offsetting methods over time: We will develop long-term management plans for our case study and other types of biodiversity offsets based on expert knowledge and experience from national and international biodiversity offsets.

 

Experimental design

Our case study will be a unique novel large-scale long-term biodiversity offset project initiated in northern Sweden as a consequence of the expansion of the Aitik mine. To compensate for loss of ca 250 ha of forest with high or very high conservation values the Land and Environmental Court of Appeal decided that two offsets areas should be sets aside and that a large number (540) of dead wood substrate should be translocated (including associated insects, epiphytes and wood fungi) from the impact area to the compensation area. To allow for a scientific evaluation of this project we have conducted baseline measures of insects, bryophytes and wood fungi in both impact and compensation areas as well as the reference landscape prior to the translocation. In addition, we have designed a field experiment were we vary the number of translocated dead wood substrates in 30 plots in the 400ha large compensation area (Fig. 1, Table 1). Beginning in 2018 we will monitor survival and spread of translocated species using trapping, field inventories and molecular methods with regular intervals.

Figure 1. Plot design

 

Management implications

Never before have deadwood translocation of this magnitude been undertaken making this project unique and we basically lack knowledge regarding the outcome of these translocation, i.e. if translocated species will survive and establish in the compensation area. But if the method is successful it could be extremely useful in biodiversity offsetting and forest restoration. To evaluate this offset project it is therefore of outmost importance and for this purpose we will engage with ecologists, biodiversity and ecosystem specialists and policy makers in Sweden and abroad.

Facts:

Project leader: Joakim Hjältén1

Associated researchers: Brownlie, SF2, Granberg Å3, Hekkala, A-M1, Josefsson T3, Jönsson M4, Lindroos O1, Lundmark T1, Löfroth T1, Nordin J5, Rudolphi J1, ten Kate K2 and von Hase A2.

Affiliations:
1Swedish University of Agricultural Sciences, 2Forest Trends, 3Enetjärn Natur, 4Swedish Biodiversity Center; 5Sveaskog.