Following RSPB's own recent report on the impacts of climate change on nature, Finlay Duncan, Birdlife Communications and Media Officer, brings news of a brand new report published today.
Birds are among the best studied species in the world, making them great messengers for the effects of climate change. As world leaders gather in Paris to negotiate a global climate change agreement at the UN COP21 summit, a new report, jointly published by BirdLife International and US Partner the National Audubon Society, details the severity of the threats of climate change. The Messengers, released today, gathers hundreds of peer-reviewed studies illustrating the many ways climate change threatens us and birds. The fact climate change will result in more losers than winners is an overriding theme. It is likely that twice the number of species will be worse off from a changing climate than the number of species that will benefit. Most bird species are expected to experience shrinking ranges, which will increase the risk of extinction for some. Population declines may also be felt more widely where species are not able to shift their distributions as quickly as the climate is changing. It’s not just birds who’ll be affected in this way. Ecological communities and interactions between species will be disrupted overall. We too face many threats, with a rise in the number of extreme weather events and greater prevalence of disease. By the year 2100, it’s expected that an additional 52 million people in 84 different countries will be vulnerable to coastal storm surges. Lower crop yields will impact the amount of food we can produce, increasing the risk of malnutrition for many. But the report also includes a strong message of hope. It details examples in which BirdLife Partners, leaders in nature-based solutions, are helping birds and communities become more resilient in a warming world. Examples include the creation of a new mainland colony for the African Penguin, with climate-induced shifts in fish stocks partly responsible for their dramatic decline in numbers in South Africa. In Europe too, conservation efforts are helping species to adapt to a changing climate; for example, with core breeding sites for Eurasian Bittern under threat from rising sea levels in the south coast of the UK, the creation of new habitats is leading to population increases. The Messengers report hopefully demonstrates that solutions from nature can deliver a series of benefits to people and to biodiversity, whilst at the same time offer an effective and accessible response to climate change. The report is available to view in full here: http://climatechange.birdlife.org
In the final blog in our mini-series Malcolm Ausden, a Principal Ecologist for RSPB, looks at how we create and manage new habitat for wildlife under a changing climate. This topic is one of the many issues covered in the RSPB's new report on the impacts of climate change on wildlife.
Changes in climate add an additional layer of complexity to how we design and manage our nature reserves. How do we decide what’s best to do now, when the climate and species’ distributions are likely to be quite different in the future? And how is the climate likely to change anyway?
Despite the uncertainties over how the climate might change, there is sufficient consensus on its expected direction of travel, to help inform what we need to do now.
When deciding actions to try and lessen the overall impacts of climate change on wildlife, it is useful to distinguish between two types of timescales. First, there are measures which we can adapt on short timescales as weather conditions change. For example, changes in climate will affect plant growth, and thereby the number of cattle that we need to graze a wet grassland to provide suitable sward conditions for breeding waders. But we don’t have to plan cattle numbers several decades in advance. Instead, we can adjust our grazing levels on a short timescale in response to growth conditions during that particular year. We just need to be adaptable, and to make informed decisions based on continually monitoring and reviewing of our actions and their impacts.
In contrast, when we are re-creating good wildlife habitat, we want to design this habitat so it continues to provide suitable conditions under a wide range of future climates. This requires taking into account how the climate, and species’ distributions, are expected to change. There are two main situations where we are doing this. The first is in the design of new coastal wetlands, to help offset expected future losses of these due to rising sea levels and increased coastal erosion (as well as to help offset historical losses through land claim). The second is in the hydrological design of our freshwater wetlands, in which we take account of expected future changes in water availability.
We are designing out new coastal wetlands so that they should continue to provide valuable habitat for wildlife under a wide range of future sea levels. A good example of this is the innovative design of the RSPB’s Wallasea Island Wild Coast Project in Essex. Innovative features at Wallasea include the creation of ‘sea level rise adaptation zones’ - gently sloping areas of land designed to maintain rare transitions between high salt marsh and non-tidal grassland under a range of future sea levels. There is an article describing the design and construction of Wallasea in the August edition of British Wildlife.
A good example of a freshwater wetland designed to help cope with expected future changes in water availability is Frampton Marsh RSPB reserve in Lincolnshire. Here, as in the rest of southern and eastern England, changes in climate are expected to reduce water availability in late spring and summer, while periods of heavy rain and drought are also expected to become more common. At Frampton, we collect water in winter (when there is plenty of it) and store it in two reservoirs, so we can use this to top up water levels on the rest of the reserve in late spring and summer. We have also designed the wetland so that different sections of it can be periodically dried out and re-flooded. This not only provides valuable, newly flooded habitat for birds, but also means that in dry years, we have the option of only keeping some areas wet, while in wetter years we keep a larger proportion of the site wet.
We have also been liaising with colleagues on the Continent to increase our understanding of the requirements of birds that might colonise (or are just about colonising) the UK, due to changes in climate and recovery from past declines. Examples of these include Spoonbill and Black-winged Stilt. We have been building the requirements of these and other potential colonists into the design of our wetlands for the future.
The fourth blog in our series comes from the British Trust for Ornithology's Science Director, James Pearce-Higgins. You can read far more on any of the topics in this mini-series on our new report on the impacts of climate change on wildlife, released one week ago.
Managing species in the face of climate change
In the UK, our peatlands are one of the environments most threatened by climate change. Active peatland depends upon a high water table to encourage the growth of Sphagnum mosses, and other vegetation, which through time, decompose and are slowly converted into peat, locking away the carbon they contain. In most upland areas, these peatlands are rain-fed, and therefore they tend to be most strongly associated with western and northern Britain.
This means that the extensive areas of blanket peatland in the UK are not only vital to protect in order to reduce greenhouse gas emissions, but that they will be vulnerable to changes in precipitation and increases in temperature caused by climate change, which can reduce water tables. The species which occur on them may also threatened by climate change in the same way. For example, the golden plover, like a number of other bird species, associates strongly with blanket peatland areas, where a flush of invertebrates in spring provides abundant food for its young. The most important of these are craneflies, whose larvae are vulnerable to desiccation when the peat dries-up in hot summer weather, providing a strong link between soil moisture, insect abundance and golden plover abundance. As a result, the golden plover population in the Peak District may be vulnerable to extinction under a high climate change scenario by the end of this century.
We are not without tools to combat this threat. Through appropriate management, it may be possible to counteract the impacts of climate change. Much of our peatlands are in poor condition as a result of historical drainage and erosion. By blocking these drainage channels, we can raise water tables, improving the condition of the vegetation, and increasing cranefly abundance by up to five times, increasing the resilience of populations of peatland birds, such as the golden plover, to climate change.
Alternatively, management may be able to compensate for the impacts of climate change by improving a species’ population status without directly addressing the climate-related mechanism causing decline. In the example of golden plovers, which can be susceptible to its eggs and young being predated by generalist predators such as corvids and foxes, this could be through management to reduce predation.
Although in the face of climate change, the long-term persistence of many of our upland birds may seem unlikely, it appears there is much that conservationists can do to slow or prevent such declines occurring. Recent evidence that populations of northern species threatened by climate change have persisted longer in protected areas likely to be managed favourably for them, than in the wider countryside, supports this. Looking to the future, our ability to replicate this model elsewhere will depend upon understanding the mechanisms driving each population’s response to climate change, and maintaining the resources to support such active intervention.