The Cairngorms Connect partnership is a bold and ambitious 200-year vision to enhance habitats, species and ecological processes across a vast area within the Cairngorms National Park. Christina Hunt is the Centre for Conservation Science’s Conservation Scientist involved in the ‘Species Indicator Project’. In today’s blog she explains how we’re investigating the impacts of forest restoration on biodiversity.

The restoration taking place as part of Cairngorms Connect includes connecting up patches of native Caledonian pine forest and assisting the natural regeneration of pine and broad-leaved trees on moorland

Habitat restoration takes a long time so we have come up with a plan to study long-scale processes over just a few years. Different sites have undergone habitat restoration for different lengths of time, so by studying these we can investigate processes that have taken place over several decades.

The Cairngorms National Park (c) Ben Andrew (rspb-images.com)

Our main study area is the Cairngorms Connect partnership area in the Northern Cairngorms but we are also conducting surveys in the east Cairngorms (our pre-restoration comparison site) and in Norway (our post-restoration comparison site).

It would take too long to survey all the species at each site so instead we have picked three important groups, which we call our ‘indicator species’. These are birds, moths and vegetation. We are using these groups as indicators of ecosystem-wide changes.

Moths such as the Poplar hawk moth (left) are distinctive and easily identified by their shape and size. Others such as the Dusky brocade (right) have to be identified by the subtle differences in colouration and markings on the wings © Christina Hunt

Our moth and bird surveys began in June but we don’t survey the vegetation until July because we need to wait until all the plants are growing and big enough to be visible during the surveys. We’re only just getting started with the vegetation surveys so in this blog post I’ll give you an overview of our moth and bird survey methods.

How do we survey moths?

Lots of moths are nocturnal (they are active at night) and many of these are attracted to light. It’s not known why they are attracted to light but it helps us survey them! The moths are attracted to the bright light of our moth trap but they will want to hide away before sunrise so the trap is filled with egg boxes to provide lots of hiding places for them.

A portable moth trap at sunrise. This trap can fold up to fit inside a rucksack, allowing me to take the trap to remote sites that are only accessible on foot © Christina Hunt

We turn on the light at sunset and then wake up really early (often around 4:30 am!) to see what moths we’ve caught. We identify the moths using ID books and then we release them. Some of the moths are really distinctive whilst others have more subtle markings that we use to identify them.

A light knot grass moth. The drawings in the book are life-size, which is helpful for identification as you can hold the moth above its picture to check the size! © Christina Hunt

How do we survey birds?

We survey birds using point counts: a type of survey where you stand in one location and record any birds you see or hear around you within a five-minute period. Birds may be hiding or may quickly fly past you so it’s important to know how to identify them by their songs and calls as well as their appearance.

It’s generally only male birds that sing (although there are exceptions), so you need to learn bird calls as well. Males and females will both call, either to keep in contact with one another or to alert others to danger. Calls often sound very different from songs so it can take a while to learn them!

One of the bird species we’re interested in is Willow warbler, which is found in areas with broad-leaved trees. The presence of Willow warbler on moorland sites is a positive sign of broad-leaved tree regeneration © John Bridges (rspb-images.com)

What do we do once we’ve collected all the data?

Once all the surveys are complete we need to prepare the data to be analysed. Rather than looking at whether a certain species is present at each site, instead we want to look at overall biodiversity.

There are lots of ways to measure biodiversity but we use species richness: the total number of different species present in an area. We would expect to find lower species richness at the pre-restoration sites and higher species richness at the post-restoration sites because restoration work should improve habitat quality. But what will be interesting is to study the Cairngorms Connect sites to work out how many years it takes for species richness to begin to increase following restoration.

Cairngorms Connect is a large-scale habitat restoration project aiming to restore natural habitats and ecological processes across 600 km2 of the Cairngorms. The project is a partnership between multiple land-managers: RSPB Scotland, Forestry and Land Scotland, NatureScot and Wildland Ltd, supported by funding from the Endangered Landscapes Programme.

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