The State of Nature Report was sobering news for us in Britain in May 2013. I told you about it at the time. But a few weeks later, evidence came in Ecology Letters that conservation efforts may be paying off in Britain, the Netherlands and Belgium. [Correction] I’ve since learned that the Ecology Letters paper was published online, the same day that the State of Nature Report appeared.
I don’t know why the sobering story got more attention than the encouraging story. Perhaps because a sobering story makes neat soundbites. I’ve posted links to both stories, so that you can judge.
Here’s a sobering soundbite. Dr Mark Eaton, a lead author on the State of Nature Report, said that ‘the UK’s nature is in trouble… declines are happening across all countries and UK Overseas Territories, habitats and species groups, although it is probably greatest amongst insects, such as our moths, butterflies and beetles… Threats including sweeping habitat loss, changes to the way we manage our countryside, and the more recent impact of climate change, have had a major impact on our wildlife, and they are not going away.’
Really? Aren’t some of those threats going away? At least here in Britain and in our neighbouring countries across the North Sea, that remark may be too simple. Early in 2013, we heard that butterflies in Britain were in trouble but then, during the same year, bees and butterflies in Britain did well.
The authors of the encouraging story in Ecology Letters said that biodiversity was being lost far too fast, until about 25 years ago. But, they said, things improved after that. ‘We found that extensive species richness loss and [loss of biodiversity] occurred before 1990, whereas these negative trends became substantially less accentuated during recent decades, being partially reversed for certain taxa (e.g. bees in Great Britain and Netherlands).’
In other words, things are getting better at least for some insects and plants.
Those authors compared four 20-year time periods: 1950–1969, 1970–1989, 1990–2009 and, when possible, 1930–1949. During those periods ‘the studied countries were subjected to substantial changes in land-use, climate and environmental policies.’ They examined data on wild bees, hoverflies and butterflies. They classified plants according to how much they rely on flower visitors for pollination. Some plants need insects or they won’t get pollinated; some plants benefit from insects but can manage without; some plants don’t need pollinating insects.
Between 1950 and 1989, ‘substantial richness changes were noted in all insect groups.’ Plants suffered too. But after 1990, ‘declines in species richness or spatial heterogeneity slowed down.’
Can this success continue? Could it be recreated elsewhere? Maybe it could. The authors said in Ecology Letters, ‘Our findings are encouraging, indicating that declines have slowed or even been partially reversed in many groups and sites in recent decades. Although current species communities may be less diverse than in the past, they still contain many species of considerable value for conservation… although we may not be able to reverse species extinctions, the trends here presented help justify the continuation of investment in conservation.’
Those authors point out that European land is ‘some of the world’s most intensively managed… but in recent decades cropland expansion has decelerated and even been partially reversed… [I]ncreased public awareness of the consequences of biodiversity loss has led to increased investment in measures to counteract the most negative impacts of industrial pollution, habitat destruction and agricultural intensification. Furthermore, farm payments have led to conversion of cropland into restored conservation or agri-environmental management areas… conservation efforts may be paying off.’
They conclude that there’s ‘potential… at least in regions where large-scale land-use intensification and natural habitat loss has ceased.’