How it all started...

  • Posted on: 10 August 2017

The  Dendrological  Atlas:  A  Legacy  in  the  Making
(Arnold Arboretum, Arnoldia Magazine, 1990.)

An interview with Hungarian botanist Zsolt Debreczy on his life’s work – a proposed fourteen-volume manual of trees and shrubs. If one were to take literally the adage "one picture is worth a thousand words," then the Dendrological Atlas project, with its proposed 3,300 full-plate drawings and 20,000 photographs, is going to be worth millions. This monumental project is the dream of Hungarian botanist Zsolt Debreczy of the Museum of Natural History in Budapest, who has been working on it since 1971. Upon completion, the Atlas is projected to cover 6,500 species and 7,200 cultivars of cold-hardy, woody plants in fourteen volumes, with a grand total of 12,000 pages.

Working in collaboration with Debreczy is his wife, Gyöngyvér Bíró, a microbiologist by training, who does the literature searches and helps with the writing and field work. Botanist-photographer Istvan Rácz has been working with Debreczy since 1976, producing the photographic documentation for the project. In addition, several illustrators, including the late Vera Csapody, have worked with the team to produce pen and ink illustrations based on Debreczy’s pencil sketches.

The Dendrological Atlas team has traveled extensively throughout the temperate zones including Asia, Europe, North America, and North Africa. They first came to the Arnold Arboretum for a brief visit in 1983, and in 1988, as recipients of a Mercer Fellowship from Harvard University, they were able to return.

The goal of the Atlas project is to create a comprehensive, beautifully illustrated work that includes all the trees and shrubs of the temperate climate zones of the world. The work builds upon the foundation laid by such authors as Alfred Rehder, W. J. Bean, and Gerd Krussmann but adds totally original illustrations, visually oriented keys, and in-depth taxonomic descriptions.

According to plans, the Atlas will consist of two parts: Gymnosperms (Volumes 1 to 3) and Angiosperms (Volumes 4 to 12). The format of the work can be seen on the following pages. Debreczy, Rácz, and Bíró hope to finish the project by the year 2000, almost thirty years after the the first drawings were made.

The following interview with Zsolt Debreczy addresses some of the questions frequently asked the Dendrological Atlas team regarding this ongoing project.

When did you start working on this project?

I started it in 1971 with Dr Vera Csapody, the renowned Hungarian plant illustrator, who had published or illustrated almost 60 books before I started to work with her. Her first undertaking, with the great research botanist Sándor Jávorka, was on the Hungarian flora - with over 4,200 drawings of the plants native to the Carpatho-Pannonian region (historical Hungary), published in 1934. After I wrote a successful book on the winter - hardy ever - greens with Vera Csapody’s illustrations, we started the Dendrological Atlas project in 1971.

Was the project originally planned to be as large-scale as it now is?

Not at all! At first we planned simply to illustrate Rehder’s Manual, the most widely used reference book for identification of temperate trees and shrubs. We started with small, two-dimensional illustrations based mainly on herbarium specimens. Following my sketches, Vera Csapody immediately worked them out in black ink. As time went on, we used more and more living specimens for making the drawings and of course they looked different from those made from pressed specimens. It soon became clear that a consistent style, a"single voice", was needed to bridge this problem. Vera Csapody was in her eighties when we switched our format to produce full-page, three-dimensional illustrations. This happened in 1975, and it marks the beginning of the project in its present format. We also had to solve the problem of consistency in the photographs, which we resolved in 1976 when Istvan Rácz joined the team. Later my wife Gyöngyvér Bíró and some younger illustrators joined the group, and the Atlas became a major project of the Museum of Natural History in Budapest.

The collecting trips started in 1977. I organized them to cover most countries in Europe, North America, North Africa, the Caucasus, and Asia Minor. We worked in the best living collections of Europe, including many English parks and arboreta, and we studied in the best herbaria as well. We soon realized that if every major woody plant species in the temperate zones was to be illustrated with two pages, this would require at least five thousand pages of illustrations. That is when the Atlas became a whole series of books. To date, almost three thousand line drawings have been done, and our photoarchive now contains more than sixty thousand pictures from which the photo plates will be assembled.

The scope of the project seems to invite collaboration. Are you working with scientists in other parts of the world?

We have already received tremendous help from many institutions, colleagues, private persons, and even family members. Without their help and generosity, our present status could never have been reached. In fact, this project is being supported by all those people who maintain the herbaria and living collections we use for study and for documenting specimens.

At first we worked with various Hungarian and Central European institutions and arboreta, and later with the excellent German, Dutch, Belgian, and English collections, such as Bedgebury Pinetum and Kew Gardens. And now we are particularly pleased to be able to work at the Arnold Arboretum, built by such greats as Sargent, Wilson, and Rehder. Today we are cooperating with numerous research fellows and scientists on a consulting basis, and we incorporate their comments and suggestions into our work.

Your project is as much art as it is science.How do you see these two often conflicting elements fitting together in your work?

Many of the illustrations may have artistic merit. The illustrator and photographer are limited by the accuracy requirements of science. The illustrations and photographs have to reflect the beauty of nature, but they do not have the same kind of freedom that art does. In the Atlas, the text and the pictures share the same pages; they transmit different information in complementary ways. We intend our work to be precise and correct in terms of science, but much of this information may be out-of-date after a few years, or decades. We believe the illustrations will retain their value long after some of the taxonomy has been revised.

In the same way, you try to fuse taxonomic botany and practical horticulture. Is this not also difficult?

We are botanists but feel we are part of both camps. While we "grew up" doing extensive herbarium and field work, we have spent far more time in living collections than most botanists. Horticulture can produce a tremendous amount of information regarding plant morphology and morphological diversity, but it is not always appreciated by botanists who find the data provided confusing or unreliable. The botanists, on the other hand, have the necessary tools and experience to interpret the data and keep track of the proper classification.

A project of this magnitude seems over-whelming because it assumes that you know about all species of trees and that you will livelong enough to complete it. Do you ever have doubts about your ability to finish this work?

I was thirty years old when I started this project and I was often told: "You are too young to start working on a project like this! "Now it would be too late for me to start a project on this scale. For the past nineteen years I have been working extensively on vegetation mapping and preparation of the Atlas. During this period I have not published anything in the field of taxonomy and I am glad that I did not. Rather, I worked with numerous colleagues and traveled as much I could, devoting most of my time and energy to seeing and understanding the problems of the whole temperate world dendroflora. As a result, I now have a deeper understanding of the diversity of this flora and a more solid basis on which to make taxonomic judgments than I would have had earlier in my career.

Undertaking a project like this does not necessarily mean that one knows everything about all kinds of trees. The value of this work, we believe, stands on its genuineness: while using others’ work, the Atlas is intended to give our own summation of the temperate dendroflora.

Are you describing any new species or varieties in the Atlas, or are you working primarily with preexisiting taxonomies?

This work differs from those produced in the era of plant exploration during the early part of this century. Taxonomic revisions will be presented in the Atlas, but these will be new combinations rather than descriptions of new taxa. New treatments of selected groups will be published elsewhere.

How do you determine what species to include and what to exclude in the Atlas? Many on the proposed list of woody plants you include in your project are not very hardy. What makes them part of your geoflora?

We define the "hardy dendroflora" as the woody flora of the winter-cold areas of the world. The dominant part of this "geoflora"is growing in the Northern Hemisphere and is a remnant of the so-called Paleoarctic or Arcto Tertiary flora. The species of this flora became established in their present locations during the cooler periods of the Tertiary period. In a sense, they were preadapted to survive the severe cold of the glaciations long before they occurred. Though this flora is an extra tropical one, some of its members extend to subtropical-tropical high mountains as a result of recent migrations, and are therefore treated in our study. Our selection of plants is based on scientific considerations rather than on merely horticultural criteria regarding the hardiness of certain woody plants.

Whom do you envision as the audience for your work? In what ways do you think that it will be an improvement upon existing works?

In general, we believe that the book will be used by both professionals in botany, horticulture, and silviculture as well as by amateurs. Botanists will use the written keys and the illustrative discussion of the variability and relationships given for each species. Others may find more useful the visual keys, the morphological illustrations, or the accounts of the cultivars. We hope many people will be captivated by the beauty of the dendroflora. The work is intended to be an improvement in keys and in the discussion of the introduction of the woody plants. It will also be more consistent in its descriptions and more systematically illustrated than other works. Except for a few historical plates, all the illustrations are original.

What do you see as the major hurdles to finishing the project on schedule, time or money?

Time! If we had enough money ... Of course more funds are needed for the Atlas, particularly for field trips, which is the only way to speed up the accumulation of data and photographs. It is also crucial to build a working relationship with some institution outside of Europe, perhaps in North America, to house our duplicate specimens, our working archives, and our reference materials. This would make it possible to have our scientific documentation preserved in more than one place and would allow other scientists easier access to our material.


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