The UK’s woodlands are worth £1.8bn in pollution removal services, according to the Office for National Statistics (ONS).
The ONS published its natural capital accounts for woodland, freshwater and farmland on 25 July. 1 It has been working with DEFRA since 2011 on valuing natural capital, aiming to incorporate it into the national environmental accounts by 2020.
The ONS found that woodlands removed more pollution and carbon dioxide from the atmosphere than any other habitat in 2015, taking out 292,000 tonnes, a service the ONS values at £1.8bn.
Some £767m of this is based on the avoided health costs associated with respiratory and cardiovascular illnesses, and the subsequent years of life gained and deaths avoided. The remaining £1.05bn is based on the amount of carbon sequestered.
The value in carbon sequestration has increased from £980m in 2008 largely because of the increase in the carbon price from £55 per tonne to £61 per tonne in 2015, as well as the UK’s timber stock increasing by 10% over this period.
The ONS also valued farmland vegetation’s removal of pollution at £176m in 2015. Physically, farmland habitats remove the most pollution as they remove a substantial amount of ozone.
However, fine particular matter (PM2.5) is associated with the highest damage to health and as woodlands remove more particulate matter than any other habitat, the ecosystem service that woodlands provide is valued higher.
The ONS also found that between 2009 and 2015 the amount of recreational time spent visiting woodlands in the UK was estimated to have increased from 245 million hours to 350 million hours. However the recreational value of this decreased from £490m to £290m because less money is being spent on travel and admission fees per trip.
The amount of timber removed from the UK’s woodlands increased from 11.2 million cubic metres in 2007 to 13.7 million cubic metres in 2015, increasing the value in this area from £157m in 2007 to £227m in 2015.
However, the ONS also found that the health of the UK’s freshwaters is deteriorating, hindering its capacity to provide ecosystem services.
Since 2008, the number of water bodies classed as in poor or bad condition has increased, while the number classed as in excellent or good condition has decreased. In 2014, 69% of rivers and canals and 62% of lakes did not meet all the criteria to receive an excellent or good status.
Its capacity to remove pollutants has decreased since 2007, along with the pollution removal value which has fallen from £25m in 2007 to £15.7m in 2015.
The ONS said that a drop in the number of water and wetland birds also suggests a decrease in the ability of wetland habitats to maintain biodiversity.
It attributes the decline, between 2002 and 2014, in part to changes in land management, such as drainage of land, intensification of grassland management and conversion of floodplain grazing marshes to arable land.