Climate change has been taken into consideration in two afforestation projects west of Hillerød, in North Zealand, aimed at protecting and optimising groundwater resources.
Denmark has the objective of doubling its total area of forest
to approx. 20%, or 950,000 ha, before the end of this century. This
means that more CO2 will be prevented from release into the
atmosphere, groundwater will be protected from fertiliser resides
from agriculture, and a more varied natural landscape will be
created, with a high degree of biodiversity. There are therefore
many projects underway around the country where forests are being
planted which are suited to a climate with warmer winters, greater
precipitation, and more violent storms. For example, 1000 ha of new
forest in North Zealand will be adapted to the future
climate.
"The primary aim of the project is to protect existing groundwater
resources and provide potential for new ones. By purchasing
agricultural land and planting forests instead, we will ensure that
pesticides and chemicals from fertilisers do not seep into the
groundwater in the future. There is therefore a ban on the use of
fertiliser and pesticides on all the land we are purchasing",
explains a ranger from the North Zealand office of the Danish
Forest and Nature Agency, who is project leader for the two
afforestation projects.
Map showing the project areas (purple shading)
Joint afforestation initiative
The project is a joint initiative by the Danish Forest and Nature
Agency, Copenhagen Energy (KE), and Hillerød Municipality. KE is
financing the purchase of the land through a user levy of approx.
DKK 0.50 per m3 of drinking water, Hillerød Municipality is
donating some sites, and has undertaken to establish connecting
paths and outdoor facilities, while the North Zealand office of the
Danish Forest and Nature Agency is managing the acquisition of land
as it becomes available. The land is being acquired through free
trade, and several years may pass before a single cohesive forest
is established.
Once the land has been purchased, the Danish Forest and Nature
Agency is also responsible for planting and future management of
the new forests. So far, approx. 140 ha of the 1000 ha planned have
been purchased during spring 2010. Several private property owners
have also begun to see the advantages of planting trees on their
own soil. For example, a generous government subsidy is payable
under the "Subsidy for private afforestation" scheme, while
landowners remain eligible for agricultural subsidies on the
planted areas in question.
"It is a long process. We do not have the option of expropriation,
so we have to negotiate with every landowner under normal market
conditions to acquire the land. The project area will therefore be
a patchwork of plots during the first few years, which we will
later have to combine into a cohesive forest area", says the
ranger.
The afforestation project by the North Zealand office of the
Danish Forest and Nature Agency is not just about planting trees.
By cutting drainage systems, wetlands are re-established which
promote natural diversity and absorb CO2. This area was a field not
long ago.
Poplar and alder are rapid growers
One of the first things the ranger and his colleagues do when
planting new forest is to make a plan for the given location,
including analyses of subsoil conditions, so they know which tree
species will grow best in the area.
"We also examine the old drainage maps for the area, to work out
where we can dam up the drain systems and thereby recreate natural
wetlands. There are two reasons for this. Firstly, retaining the
water on the land instead of letting it drain off into fjords and
lakes leads to maximum groundwater formation. Secondly, it is much
quicker to create natural areas where there is water present. It's
fantastic to work with nature. As soon as you stop cultivation, it
doesn't take long before pioneer species such as oak, birch and
willow begin to appear", says the ranger. He has a particular
interest in poplar trees, which he feels have been overlooked as a
species in Denmark, since Danish production of matchsticks and
cheese boxes came to an end after the boom years in the 50s and
60s.
Both poplars and alders will therefore be used widely as a
pre-culture for the tree species which will later make up the
forest. Once the slow-growing tree species, mixed with hornbeam
(Denmark's hardest tree species) and others, have become
established, the poplars and alders will be removed again - cut
into wood chips and taken to a combined heat and power plant.
Birth of a forest: Poplar and alder trees, as shown here, will
initially be planted on many of the blocks of land acquired.
Only hardy species used
The Danish Forest Act stipulates that over 50 per cent of
a forest area must be planted with trees. The intention is to plant
approximately 55 per cent of the new forest areas in North Zealand,
and allow the rest to stand for recreational purposes and as
grasslands which may develop into marshes etc. over time. Valley
areas will also be left clear of trees. This will lead to formation
of new wetlands where precipitation can collect.
"Many people imagine that when we plant a new forest, we plant
long straight rows of spruce, with pitch darkness in between. This
is far from the truth for these projects. Firstly, we don't use any
spruce, as they have been found to be very sensitive to climate
change. We are only interested in stable deciduous tree species,
mixed with a little Scotch pine. This is a mix of species able to
withstand the major storms climate change will bring. Secondly, we
are seeking to create a varied natural mix which is interesting to
visit and able to withstand climate change", says the ranger.