Today, the amount of insects squashed on car windscreens is smaller than 40 years ago. You can no longer find bladder wrack, or bladder fucus, on the shore at your summer cottage. Such everyday observations are linked with biodiversity loss, a hot topic in recent public discussion.
Even in Finland, one in nine species is threatened, and many previously common ones have declined.
According to Pasi Sihvonen, Director of the Zoology Unit of the Finnish Museum of Natural History, biodiversity loss is a dominant topic for a reason.
“It’s about the survival of humanity as well. Without well-functioning ecosystems and ecosystem services, we will not cope. We need clean water and the food produced as a result of pollinators’ activities. For the time being, our understanding of the progress of biodiversity loss is deficient. We know that the number of mammals and amphibians has decreased. In contrast, our understanding of the state of most insect groups is patchy.”
There is also a great deal to uncover in the interrelations between different species. More information is needed to stop biodiversity loss.
“Biodiversity loss can be compared to an aeroplane that is losing rivets one by one. The plane will stay in the air even if a couple of rivets fall off. But how many rivets can it afford to lose before it crashes to the ground? Similarly, we don’t know how many species can disappear without it affecting the ecosystem. Will the system stop working when 10% of the species disappear, or will we continue to scrape by even if one-fifth of them have been lost?” Sihvonen says.
Better conservation with monitoring data
With the help of long-term monitoring schemes, we gain information on the progress of biodiversity loss. They reveal whether a species or a group of species has increased in abundance, declined or remained unchanged.
Thanks to monitoring, conservation measures can be targeted at declining species and their habitats. Monitoring data on species numbers cover mainly Europe and North America. From an international perspective, Finland is at the forefront of such surveys. Our monitoring schemes have continued for longer than in many other countries.
The longest ongoing scheme in Finland focuses on birds, whose ringing began in 1913. Since then, more than 13 million birds have been ringed in the country. The monitoring of the number of butterflies commenced in the early 1990s and that of moths in the mid-1990s, while flying squirrel and pollinator monitoring began in 2003 and last summer, respectively.
“We wanted to monitor pollinators earlier, but received funding for it only now. Decision-makers may have been influenced by international news on pollinator decline. Launching new monitoring schemes also requires specialists in the field, in addition to which volunteers are often trained for them.”
Uninterrupted monitoring and time series are extremely important for research to identify long-term trends. Time series have revealed that, for example, the number of individuals in even common bird species has decreased. A similar decline is not evident among butterflies, although individual species have disappeared almost entirely. At the same time, dozens of new species have arrived in Finland from the south.
In Finland, monitoring relies largely on enthusiastic hobbyists. They collect observations that are compiled and analysed by one or two salaried researchers. Many other countries do not have a similar tradition of volunteering.
“Data are accumulated at a very low cost. Still, funding must be separately sought from funders every year. A long-term approach would provide continuity in research.”
Ordinary citizens can also collect observations. By storing your species observations in the Finnish Biodiversity Information Facility service, you make them available to researchers, municipalities and entrepreneurs.
The happy tale of the white-backed woodpecker
Monitoring and targeted conservation measures have yielded good results. One positive example is the recovery of the white-backed woodpecker population from critically endangered to vulnerable.
At its lowest level in the 1990s, only 13 nesting pairs were known in Finland. Today, the number is approximately 500.
“The population started to recover when the mandatory conservation of the best woodpecker forests began in the 1990. Based on research, white-backed woodpeckers thrive in old broad-leaved forests with a lot of decaying trees and a small number of young conifers,” says Postdoctoral Researcher Petteri Lehikoinen.
In addition to conservation, the population has been boosted by net migration from Russia, and possibly also by the winter feeding of woodpeckers. Even global warming may have helped the birds survive through the winter.
The white-backed woodpecker is what is known as an umbrella species. Protecting habitats suitable to it benefits a number of species that thrive in a similar environment. Among other species, this gives beetles partial to decaying wood another lease on life.
Not just the threatened ones
Discussion on biodiversity loss often turns to endangered species such as the white-backed woodpecker. Also important, however, is how common species fare.
“The decline of a common species makes it increasingly vulnerable, as its genetic diversity narrows. If the habitat changes, the population will have fewer traits that could help the species survive under changed conditions,” Sihvonen says.
Common species that have already declined include the grey mountain carpet, the catswood – a plant previously familiar from roadsides – and the sparrow.
What will be particularly problematic is if what are known as key species become rare. For example, the previously mentioned bladder fucus provides a habitat to dozens of different species. And there are as many as hundreds of species directly or indirectly dependent on the aspen.
“We only know some of the interdependencies of different species. It’s difficult to assess how the extinction or increasing rarity of a single species affects an entire ecosystem,” Sihvonen notes.
Everyone can make a difference
Through research, biodiversity loss has been confirmed to have begun centuries ago. Researchers have been talking about the phenomenon for decades. And yet, the topic has only recently broken through to public discussion.
“I’m glad we’re finally talking about it. The topic has been highlighted by the media, and it is finally on the political agenda. For instance, the recently reformed Nature Conservation Act obliges parties who destroy habitats to provide substituting habitats elsewhere,” Sihvonen says.
He emphasises that everyone can do their part to curb biodiversity loss. The methods are largely the same as in the fight against climate change. You can make a difference through your lifestyle and consumption choices.