Botanical Garden goes to Far East; test of a theory

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Timo Koponen and Aune Koponen

The University of Helsinki is currently building a new botanical garden at Kumpula Manor, ca. 3 km N of the site of the old garden in Kaisaniemi. Creation of a completely new scientific garden offers a rare possibility to test the phytogeographical theory of bioclimatic vegetation zones.

Early studies in vegetation science

In the early history of botany studies in Finland two disciplines were internationally recognized as being of high standard, namely the taxonomy of cryptogamic plants (see Universitas Helsingiensis 2/1993) and phytogeography, especially vegetation science. The scientists of our University were among the first to develop criteria by which plant association should be described and classified, what they tell us of the physical condition of the habitats, and even among the first to apply this type of knowledge to agriculture and forestry. Johan Petter Norrlin (1842-1917) studied plant topography and believed that plant associations reflect the soil and the microclimatic conditions of the habitat; in habitats with similar vegetation the same ecological conditions prevail. Aimo Kaarlo Cajander (1879-1943), basing his studies on this same approach, developed Finnish forest-site type and peatland-type classifications. One of Norrlin's students, Ragnar Hult (1857-1899), was a forerunner in developing the methodology of vegetation science. He emphasized the physiognomy of vegetation and paid less attention to its ecology. His ideas were followed in Sweden, making him actually the father of the "Uppsala school" of vegetation science. The students of these vegetation scientists and these students' students continued to study the vegetation of Finland, so that now the major vegetation types of our forests, peatlands and lakes are well known.

The theory of bioclimatic vegetation zones

Aarno Kalela (1908-1977) focused on to the regional features of vegetation in Finland and North America. That Finland is a level country which lies in the boreal vegetation zone is advantageous when the zonation of vegetation is studied; regularity of vegetation is more difficult to discover in a mountainous area. Based on much material from Finland, Kalela divided the boreal zone into several subzones. Kalela's work was continued by Jaakko Jalas (1920-), Teuvo Ahti (1934-) and Leena Hämet-Ahti (1931-). Using many floristic, climatological and vegetational parameters and characteristics they first expanded the originally Finnish zone system to cover all of Scandinavia and later the whole northern hemisphere. When Sakari Tuhkanen (1952-) tested the boundaries of these vegetation zones against many climatological parameters, he found corresponding bioclimatic areas in the southern hemisphere, especially in South America. The Finnish system has been found useful by other botanists as well; it explains not only the distribution of vascular plants and vegetation types but also the distribution of other organisms, such as bryophytes, lichens and birds.

As a result of more than one hundred years of research by several generations of Finnish botanists, we now have in hand a very valuable tool: system of bioclimatic vegetation zones. This means that we know and can predict which areas abroad correspond bioclimatically to any area in Finland. This is very useful knowledge which can be applied in agriculture, forestry, and horticulture. But how can such a theory be tested? By transport experiments, moving plants between bioclimatically corresponding areas!

New Botanical Garden at the University of Helsinki

The Botanical Garden of the University of Helsinki was established in 1678 as a herbal garden of the Academy of Turku. The garden was moved to Helsinki in 1829 in connection with the establishment of the Imperial Alexander University. Czar Nikolai I then (in 1828) ordered that an area of Helsinki City public parkland was to be given to the University for its botanical garden. The new garden was fully planted by 1833, and has been in Kaisaniemi since then. The 4-hectare garden, with its outdoor garden and greenhouses has been a remarkable resource for teaching botany not only in our University but in many other schools as well, such as the horticultural and art schools. The greenhouses are a popular tourist attraction with ca 17 000 visitors yearly.

In the early 1980's the University decided to build a new campus in the Kumpula area. From the very beginning it was clear that the Botanical Garden must be one of the first institutes there; trees grow slowly. Kumpula has a good facility for the garden, the old Kumpula manor with its previously cultivated 6-hectare surroundings. Planning of the new garden began in 1987, and basic construction was completed in 1994. The garden has now a good laboratory, a library, and office facilities in an old restored building. A greenhouse was built for the propagation of plants for the new garden. The new garden will include a garden of ornamental plants, a garden of economic plants and phytogeographic garden as well, where plants will be located and cultivated according to their original areas. These geographical sections will include collections of Japanese plants, of plants of the Far East, meaning the Russian Far East and Northeast China, collections from eastern and western North America, and a European collection.

All our plants will originate from their natural habitats. Part will come from international seed exchanges, and because seeds of some other plants, especially trees, are inadequately available, these will be obtained from a series of excursions.

Establishment of a new botanical garden is a rare event and also a challenging possibility to test and introduce new plants and varieties. This is clear from the fact that our excursion to Japan was only the second excursion abroad to be arranged by our garden; the previous excursion was that of Peter Kalm to North America in 1748-1751!

Theory and practice meet; where to go for seed-hunting?

Our research project proposal, "Introduction of new ornamental and horticultural plants into southern Finland," which was accepted by Helsinki University, was based on a plan to arrange scientific expeditions to areas corresponding bioclimatically to conditions in Helsinki. Our garden lies in the border area between the hemiboreal and southern boreal bioclimatic vegetation zones, and the climate is moderately oceanic; summers are cool and winters moderate, but very low temperatures (below -30 EC) may occur.

On the basis of the research of the Finnish phytogeographers mentioned above, we knew the four major areas outside Europe in the northern hemisphere which we should visit. In Asia we should go to Japan, to the island of Hokkaido at ca 400 - 800 m elevation, and to the island of Honshu at ca 1 000-2 200 m. In continental Asia, other bioclimatically corresponding areas are to be found in the high mountains of Korea and Northeast China, and in certain areas in the Russian Far East, such as Amur, Sachalin, and Kamchatka. In North America, corresponding areas can be found in both eastern and western Canada, especially in the "interior wet belt" of British Columbia. Of these, Hokkaido in Japan, Northeast China, and British Columbia were selected. The excursions to Japan and China were made in 1993 and 1994, respectively, and British Columbia is our targit this year.

Preparation and realization

The most significant element in collecting plant material for scientific purposes is careful documentation. Only when the localities and other details are known can the plants later be used for purposes such as plant breeding and experimentation. A minimum of five participants is necessary on such excursions. There must be a leader who arranges funding and logistics, a specialist who selects the plants to be sampled and supervises the collection numbers, at least two collectors who are specialists in horticulture (one of them able to climb tall trees), and a person who documents the collected material by voucher specimens. The field work was rehearsed in Finland before the excursion, and we had all the collecting and documenting equipment with us during this practice. Everyone learned his or her duties.

In the group there must also be persons who know the local conditions and the language. We used our earlier personal contacts and proposed cooperation with three gardens, which all agreed: in Japan the Botanical Garden, University of Hokkaido in Sapporo, in China the Arboretum of the Institute of Applied Ecology in Shenyang, and in Canada the Devonian Botanic Garden in Edmonton. In Japan we had with us - in addition to Dr. Takahashi Hideki from Sapporo - Professor Cao Tong from China and Professor Dale H. Vitt from Canada. In China, Professor Cao Tong organized the field excursions, and Professor Vitt was in the group. This year in Canada Professor Vitt will arrange the logistics, and there will be representatives from both China and Japan. Cooperation in the field has been very good indeed, and sending material to Helsinki after the excursions entailed no difficulties whatever.

Results and prognosis

In Japan we collected 400 and in China 330 numbers of mostly seeds. We also sent twigs of trees in test tubes by express mail to Helsinki for micropropagation, which is a part of our project. Moreover, both in China and Japan, because some rather large samples of seeds were collected, a limited amount of these could be offered in international seed exchanges.

After the excursions the seeds were sown and placed outdoors to induce germination by natural cold treatment. Some of the Japanese seeds germinated in the spring of 1994, and the plants grew well. A total of 13 000 plants were produced, of which 49 woody plant species and 1 450 individual plants have already been planted in the Japanese section of the phytogeographic garden. The seeds from China will germinate in the spring of 1995. To test the hardiness of material over a wider area we have cooperation agreements with three city gardens, those of Kerava, Kotka, and Riihimäki, and with three horticultural schools, those in Harju, Lepaa, and Mäntsälä. We gave them plants or seeds from our material, and they will grow these and report to us how well they thrive.

Did we select the areas to visit correctly? We will know only after many years whether we were successful or not, and whether the theory of bioclimatically corresponding areas proves correct and useful. In the best case the University of Helsinki will have a very rich garden deserving international comparison. For instance, the material from China included seeds of seven different species of birches and nine different species of maples. We brought back seeds of ca 90 Japanese and 70 Chinese woody plant species, which have not previously been tested in Finland. At the very least, these have a better prognosis than those of our famous procedessor Peter Kalm. Only three of the plants (Fanleaf hawthorn, Purple-flowering raspberry and Virginia creeper) which he introduced from North America have survived in Finnish gardens to the present day. Kalm's failure was due to the fact that he did not have the necessary phytogeographical knowledge available. He travelled mostly in areas which were not bioclimatically correponding to southern Finland.

The new garden will be opened to the public in 2010. Welcome!

Timo Koponen WAS Professor of Botany and the Director of the Botanical Garden. Aune Koponen, his wife, WAS the Intendent of the Garden, and Docent Lecturer in Botany.