The Forest Plantations in The Greenlandic Arboretum
A surprisingly lush vegetation is found in the inner south Greenland valleys. But it is vegetation that is species-poor. There are no conifers except for the creeping common juniper (Juniperus communis var. saxatilis). The reason for the lack of species richness is found in Greenland's isolated position which makes it difficult for plants with heavy seed to invade. This includes most of the conifers and species of the pea family.
Fig.1: Shrub consisting of Gray-leaf willow (Salix glauca) and fireweed (Chamaenerion latifolium), The Qingua valley. Photo: Jørgen Kjær Jensen, July 2006
However, a potential forest zone is indicated by the brushwoods of mountain birch (Betula pubescens ssp. czerepanovii, previously ssp. tortuosa) (Fig. 2) and the more scattered occurrence of the Greenland mountain-ash (Sorbus groenlandica) (Fig. 3) as well as American green alder (Alnus crispa).
Mountain Birch are found in a number of localities. It is mainly found as single individuals in the coastal regions, while only found as a luxuriant forest (continuous with heights above 5 meters) in isolated localities – here in association with Greenland mountain ash. The Qinngua valley (Fig 1, 2) being the most well-known forest locality was protected by law in 1930 by the Danish Colonial Administration.
In the planning of a new plantation it is the localities, with luxuriant shrubs consisting of willow and birch, that are the indicators of a potential treeline. However, due to intensive cuttings, followed by sheep browsing, areas within the treeline are often found treeless, resembling a tundra landscape. The main problem then is to determine whether the absence of shrub is caused by this factor or maybe due to an unfavourable climate.
The distribution of Mountain Birch has previously been mapped but it has never been related to the local climatic gradient and furthermore climate data from the birch forest zone has never been collected.
In the summer of 2007 the first project of its kind was initiated in Southwest Greenland. The project surveys and compares the climate in the Tasermiut Fiord including the undisturbed Qinngua Valley with simultaneous data collected in the Tunulliarfik Fiord system. The latter being an area where human-caused disturbance has been significant since the Norse settlement just before A.D. 1000.
The project will determine whether climate elsewhere in Southwest Greenland is the main factor limiting birch from developing into treelike structures, like those found in the Qinngua Valley. Future data obtained from the above mentioned areas will help to determine if human activity is causing the failure of birch re-establishment. In addition the data will help to identify potential areas for future protection or production.
The project was financed by the “Aase og Jørgen Münthers Fond” foundation and is conducted by Rasmus Christensen (See the below contact information)
Fig.2: Forest of Mountain Birch in the Qinngua valley, Nanortalik District. Photo: Rasmus Christensen, July 2007
Fig.3: Greenland mountain-ash (Sorbus groenlandica), “Klosterdalen” valley, The Tasermiut fiord. Photo: Rasmus Christensen, July 2007
The lack of warmth during the growing season (low heat-sum) is a strongly limiting factor for tree growth in Greenland. Before winter starts growth should be completed, and new shoot and buds should have been hardened. Violent, dry foehn (Chinook) winds from the inland ice cap occur during the whole year. During the winter, these foehn winds cause complex damages.
If one is to develop a picture of where the forest limit occurs in Greenland, can one look at the vegetation in similar areas in North America. The nearest relative to the Greenland mountain-ash is the northeast American mountain ash (Sorbus decora). It occurs neither higher, nor further north that the forest limit which is created by the conifers. Thus it is probable that conifers can grow in the summer-warm, inner fjords in Southwest Greenland where one finds the Greenlandic mountain-ash. In the White Mountains of New Hampshire the tree-line forming balsam fir (Abies balsamea) and black spruce (Picea mariana) and on Labrador's northern limit for the mountain-ash one finds black spruce, white spruce (Picea glauca) and tamarack (Larix laricina). At this area 5000 self-sown seedlings were collected in 1993 for planting in Greenland.
The oldest surviving introduced trees in Greenland are "Rosenvinges Trees", Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) from northern Norway. These trees were sown near Narsarsuaq in 1892. Today there are four surviving Scots pine trees, which are 5 meters high and very strongly wind-shape (Fig. 4)
Fig. 4. Rosenvinge's trees in Qanasiassat, 4 Scots pine (Pinus sylvestris), from north Norway on a 5 m hump, sown by the botanist Rosenvinge in 1892. Photo: Poul Erik Pedersen, August 2000
The natural Greenland brushwoods and "Rosenvinges trees" inspired The Royal Agricultural and Veterinary University (C.A. Jørgensen and C. Syrach-Larsen) and the Forest research department (C.H. Bornebusch) to study the possibilities of planting forest in Greenland. Since 1953 the Upernaviarssuk Research station, the Arboretum of the Royal Veterinary and Agricultural University, and the State forest tree-breeding station as well as the Icelandic forest council have worked to procure suitable forest plants. In the first optimistic period and up to 1950's a wide variety of northern material was tried. With few exceptions all these trials failed in establishing trees with notable exceptions. Survivors included Siberian larch (Larix sibirica), Scots pine (Pinus sylvestris) and Norway spruce (Fig. 5) from northern Norway, white spruce and the white spruce-Sitka spruce hybrid called Lutz spruce (P. glauca x sitchensis or P. x lutzii ) from the southern Alaska as well as a few others. The especially cold summers of 1982-1984 filtered out the planted trees and provided the basis for a more narrow selection of species and proveniences for more extensive plantings.
Fig. 5: Norway spruce (Picea abies) from north Norway, Qanasiassat plantation, planted in 1953. Photo: Poul Erik Pedersen, August 2000
Fig.6: Abies lasiocarpa from 1982 in The “Kuussuaq” forest, The Tasermiut fiord. Photo: Rasmus Christensen June 2007.
The head of the Arboretum (Dr. Søren Ødum, 1937-1999) in cooperation with the forest officer Poul Bjerge (Upernaviarsuk research station), was the driving power for the Greenland planting trials up through the 1970's and through to the end of the 1990's. Søren Ødum made a colossal work to find the right plant material, and many species and provenances were introduced by Søren Ødum to the plantations and gardens of Greenland. Søren Ødum started trial plantations in the community of Nuuk (Qooqqut), Kangerlussuaq/Sødre Strømfjord and founding the Greenland Arboretum in Narsarsuaq.
The most promising possibilities for finding the best adapted plant material for the Greenland climate has been shown to be collecting trips, where the material is purposefully collected near tree-lines. For a good result it is critical that the trees are adapted to a short growth season. They need to have a late timing of bud-break, an early stop of growth, and an early maturation of the shoot. By collecting material from a little more northerly latitudes than the planting area, one can often obtain a little earlier stop of growth and earlier shoot hardening. In this way the risk of freezing and scalding by the foehn winds after a cold summer is reduced. The price is that the annual height growth is somewhat reduced.
Commercial seed from tree-line areas is not normally found on the market because the long time between good seed years when it is possible to harvest a large amount of seed of good quality. On the collecting expeditions seed is collected where and when it is possible, and in addition a large number of small plants are dug up for later planting. Thereby time is won with an earlier test of the provenances and material, which can also be established in more accessible seed plantations.
Since 1981 the main effort has been to obtain material from directly from the forest tree-lines. Collecting expeditions have been made to the following areas: Alaska and Yukon (1988 Søren Ødum), Alaska, Yukon and North West Territories (1991, S. Ødum, Kenneth Høegh, Mads Nissen, Thomas Guldbeck), at Hudson Bay in the northern Manitoba and Northern Quebec/ Ungava Bay (1993, S. Ødum, K. Hoegh, M. Nissen, Poul Bjerge), the Euorpean Alps (1998, S. Ødum, P. Bjerge), the northwest Nepal/Himalaya (1999, K. Hoegh) and the Northern Urals and Kamchatka Peninsula in Russia (2000, K. Høegh, Agricultural Extension Service of Greenland), Jerry Leverenz (Arboretum in Hørsholm, Denmark) Thor Thorfinnsson (The Icelandic Forest Service, Iceland).
Besides the collection expeditions, planting have continued in Narsarsuaq of Siberian larch, especially of the Arkhangelsk provenance in Russia, delivered from Iceland. In all 75,000 small plants of Siberian larch have been planted in the Greenland Arboretum form 1992-2002.
The most suitable planting locations in Greenland are deep in the fjords, sheltered from the foehn winds and in areas where trees can be helped to establish by native brushwood which improves the local climate. Areas should be free of sheep or fenced in. A nursery has been established at the research station at Upernaviarssuk (10 km from Julianehåb) by the local forestry officer, Poul Bjerge. It was here that plants were produced earlier, but during the later years plants have been primarily delivered from the Arboretum in Hørsholm, Denmark, Iceland and northern Norway or dug up as small seedlings at diverse tree-line areas.
At the Upernaviarsuk research station, above the forest limit for mountain birch and Greenland mountain-ash, a small plantation of about 0.1 hectare, planted in 1960, where the low arctic climate has developed krummholz-types of primarily Siberian larch, Scots pine from Northern Norway, white spruce and Lutz (hybrid) spruce. It is noteworthy that the Lutz spruce has been able to survive as a approximately 1.5 m tall krummholz-trees with a stem diameter at the root collar of up to 30 cm. Balsam popular (Populus balsamifera)(Fig. 7) and Feltleaf willow (Salix alaxensis) (Fig. 8) are capable of developing into small trees on good soil in Upernaviarsuk and in the nearby Qaqortoq/Junlianahåb. The last named species has probably a much smaller requirement for summer warmth than most other tree-line trees.
Fig.7: Engelmann spruce (Picea engelmanii), Lodgepole pine (Pinus contorta) og balsam poplar (Populus balsamifera)in Poul Bjerge’s garden in Qaqortoq. An otherwise treeless environment near the outer coast of South Greenland. Photo: Rasmus Christensen, June 2007
Fig. 8: Felt-leaf willow (Salix alaxensis), "Kaneq" in Erik Petersen's garden, planted 1995 - the proud owner in front. Photo: Kenneth Høegh, August 2007.
The willow tree in the above picture is of a clone called “Kaneq”, which is the Greenlandic name for the Icelandic clone “Hrima”. It is the most treelike clone of all the Alaskan willow-clones that has been tested in Southwest Greenland, origining from Cooper River Delta in the southernmost Alaska. “Kaneq” is extremely robust and will develop in to a polycormic tree even in the cold summer environment of Nuuk – Mainly on south-facing localities protected from the wind. An astonishing specimen is to be found near the house of “Hans Egede” in Nuuk.
At Tasermiut Fjord one can find two small plantations (Fig. 9, 10) of the naturally occurring hybrid Lutz spruce from the Kenai Peninsula in Alaska. These plantation which were established in 1960 and cover an area of 5.5 hectares in total. These Lutz spruce were 2.5 m tall on average in 1987 with individuals up to 4 m tall in these stands. Today, in the summer of 2007, the trees are up to 10 m tall. Pure white spruce from Knik River near Anchorage also occurs in these stands but grows a little more slowly. Siberian larch is about 10 m tall today, but the stand is decimated by larch cancer (Potebniamyces coniferarum).
Fig. 9: The two plantations at ”Kuussuaq”, The Tasermiut fiord seen from a helicopter. Photo: Rasmus Christensen, June 2004
Fig.10: The first timber cut in Greenland. Ole and Jonas from the municipality of Nanortalik were the first Greenlanders to become lumbers . “Kuussuaq” forest. Photo: Rasmus Christensen, July 2005
In 2005 the first timber was harvested from the plantation in the Tasermiut Fiord (Fig. 10) – first of all this was done to thin the stand and thereby increase the annual growth in the residuals but also as a project to estimate the profitability in forestry in Greenland. The logs harvested in the plantation will be used as fencepoles at Upernaviarsuk Agricultural Research Station.
The project was financed by the “Augustinus Fonden” and “Bodil Pedersens Fond” foundations and was conducted by Rasmus Christensen assisted with crew from the Nanortalik municipality.
In the area of Narsarsuaq, not long from Rosenvinge's trees, is a small plantation, which was started in 1954. It has many tree species, for example Norway spruce (Fig. 5), Scots pine and lodgepole pine (Pinus contorta). Siberian larch from 1957 was up to 11 m tall in the summer of the year 2007 in this plantation and a forest climate has clearly developed, in spite of the small plantation size of about 1 hectare.
In 2003 the plantation was mapped including registrations of the first self-sown larches in Greenland. The mapping was accomplished by Birgitte Jacobsen and Katrine H. Nielsen as a Bachelor thesis at the Danish Agricultural University. (See below contact information)
Fig.11: Sibirian Larch (Larix sibirica var. sukaczewii), planted 1998. The Greenlandic Arboretum. Photo: Rasmus Christensen, July 2007
In Narsarsuaq there are brushwood-covered, south, and west facing slopes that have been planted with over 100,000 trees (comprising 105 species and 400 provenances), in what can now be called the Greenland Arboretum (Fig. 12).
Fig.12: A section of the Greenland Arboretum in Narsarsuaq with Lutz spruce (Picea x lutzii) and Siberian larch (Larix sibirica) planted respectively in 1988 and 1986. Photo Kenneth Høegh, June 2000.
Within this 200 hectare area one can find representatives of nearly all the subarctic and northern subalpine tree-line developing species of the northern hemisphere. Many of the species are represented with a large number of difference geographic races (provenances). The most complete collections are of white spruce, the variety of Siberian larch from the northwest par of its range (L. sibirica var. sukaczewii) (Fig. 11), subalpine fir (Abies lasiocarpa) (Fig. 6) and the inland form of lodgepole pine (P. contorta var. latifolia) (Fig. 13),
Fig.13: Lodgepole pine (Pinus contorta)from Haines, Alaska, USA, planted 1984. The “Kuussuaq” forest. Photo: Rasmus Christensen, June 2004
Engelmann spruce (P. engelamnnii), (Fig. 14) as well as Nordic tree-line provenances of Norway spruce and Scots pine as well as diverse broadleaved trees (Fig. 15). Rarer species such as subalpine larch (Larix lyalii), Larix lyallii x L. occidentalis, Himalaya birch (Betual utilis) and Scots Elm (Ulmus glabra) (Fig. 16) among other can also be found here.
Fig.14: Engelmann spruce (Picea engelmannii) in Narsarsuaq from Rio Grande del Norte, Colorado, USA, planted 1991, Photo: Rasmus Christensen, June 2007
Fig.15:Alder (Alnus fruticosa) planted 1997. The Greenlandic Arboretum. Photo: Rasmus Christensen, July 2007
Longer north are test plantations in Ivigtut, within Amaralikfjord, in Qorqut within Godthåbsfjord, and in Sødre Strømfjord.
The annual growth-rate of the Greenlandic forests is very similar to what is observed in the rest of the subarctic areas in the Northern hemisphere. In Lapland it takes Scots pine and Norway spruce several hundred years to reach a height of about 15 m and a diameter of 40 cm. Tests with tree-growth have shown that Greenland is able to compete with this. Future larger scale plantings are planned and mainly in the region between Narsarsuaq and Tasermiut Fiord.
Fig.16: Scots elm (Ulmus glabra) in the “Iscentralen” garden in Narsarsuaq. Photo: Rasmus Christensen, June 2007
In the northern fjord landscapes along Godhåbsfjord, the trees will most likely be, if nothing else, something exotic to experience. But the trials in Sødre Strømfjord will probably serve as a scientific experiment to test where the northern limit to the forest-line occurs. With their marginal position the Greenland forest tree stands are well suited to detect natural and man-caused climate changes and register the results in their growth rings.
The arboretum and the activities in Southwest Greenland are administrated by the association “Narsarsuaq Orpiuteqarfia”.
For further information on these activities in Greenland please contact “Narsarsuaq Orpiuteqarfia”: