In the absence of reference sites, a modified BACI design (Downes et al., 2002) was used, whereby a control site and treatment site were located on each stream (Figure 1).
|Figure 1: Layout of treatment and control sites|
The key features of the study are:
- A rigorous experimental design comprising multiple locations with sampling conducted before and after restoration at control and treatment sites;
- Each control site is located upstream of a treatment site so it stays largely unaffected by any restoration works (see Figure 1);
- Each experimental site is roughly 1km in length and includes both sides of the stream to a minimum average width of ~20m;
- Replanting is carried out by local waterway managers i.e. Catchment Management Authority's (CMAs), following current best practice guidelines;
- The establishment of all experimental sites receives long-term support from landholders.