England: Restoring Kew Gardens

THE TIME IS December, 1987. Just to the west of the azaleas, more or less in the center of the Royal Botanic Gardens at Kew, two uprooted southern beeches lean crazily into the crown of a beautiful London plane tree. Three or four more trees are dead on the ground around the plane; those trees have already been marked for eventual disposal. One particularly fine casualty has an A label on it and will be used for veneers; another is suitable for furniture. A lute maker has claimed some samples of (7-grade lumber and will build one complete instrument, which, along w ith illustrations of all the intermediate stages from tree to finished lute, will form an exhibit for the botanical gardens’ museum.

But first the two askew trees must come down and out. Kew’s tree surgeons usually climb the trees that demand their attention, but to lop the branches off these they’ll use a large cherry picker. The Kew tree gang wears armor—Kevlar-lined boots, and pants made of eleven layers of ballistic nylon, which can clog the chain of a saw before it cuts through to a leg. In addition, they are taking pains this year to avoid carelessness. “You have to know what is going on in a tree when you’re topping it,”says Roger Howard, the tree-gang supervisor. “We’ve cut so much recently that we’re getting fed up with cutting.”

But cut they must, now and for years, as they attempt to repair the damage inflicted in the worst disaster ever to strike the Royal Botanic Gardens—popularly known as Kew Gardens. In the space of eight hours, between midnight and daybreak, on October 16, 1987, Kew, one of the oldest botanical gardens in the world, was torn apart. A storm of a severity essentially unheard of in Britain swept in from the southwest, and its winds cut like Paul Bunyan through woodlands across the width of Britain.

At Kew, just to the west of central London, some 500 trees were demolished and another 500 so badly damaged that they require major tree surgery. Among the dead are some that will be impossible to replace. The hurricane claimed an Iranian elm planted in 1761, tw years after the Princess Augusta founded Kew. Another elm, this one from the Himalayas, survived Dutch elm disease only to collapse in the storm. The Queen is said to be quite distressed that a walnut she planted in 1959 has predeceased her. All together, the mess created during one night of wind is expected to take Howard’s crew three to four years to clear completely.

The losses at Kew, however, will have consequences that extend much further than the confines of the gardens’ nearly 300 acres. Kew is an independent body, paid for by the British government at a cost now running to about $20 million a year. Kew’s age and tradition, together with that rather comfortable level of funding, has enabled the gardens to accumulate a collection unique within the botanical community. The herbarium, for example—probably the world’s largest—contains between five and six million dried plant and seed specimens (no one knows the precise figure) from all over the world.

What makes Kew the most significant botanical gardens in the world, though, is not simply its collection of plants. The living collection at Kew provides a laboratory in which to observe plants in action. Kew is famous for its greenhouses and its collection of tropical plants, but at the heart of the gardens stands the arboretum, a collection of 16,000 tree and shrub specimens from the earth’s temperate regions. The thousand trees lost or nearly lost represent 10 percent of the total number of trees wdthin Kew’s grounds. Each tree represents a decision, taken as long ago as two centuries, about what Kew ought to contain.

For roughly the past two decades Kew’s staff has sought to change the gardens, or the plants to be grown there. Now—the silver lining—the destruction wrought by the storm has given them greater latitude than anyone has had since the turn of the century to press the pace of that transformation. While the rest of the world’s botanical-garden community watches closely, wdiat will emerge from the wreckage, over a period of decades, is a garden designed to be a particular kind of scientific tool.

Kew has had to choose what plants to try to salvage from the debris left by the storm, what to abandon, and what to bring into the gardens from outside the collection. The up or down choice comes first: which trees—or, more properly, which trees’ genes—to save and which trees to turn into compost. As soon as the storm had subsided, the nursery staff at Kew set out to collect the genetic stock of the most important specimens that had fallen.

Unfortunately, the propagation of new plants from old cuttings is not a very straightforward operation, and the savagery of the storm created the worst of conditions for it. “If we know we are going to propagate a tree,” Martin Staniforth, the nursery supervisor, says, “we can control the timing, select the material.”The storm knocked down mature trees, with relatively few new, fastgrowing shoots of the sort suitable for propagation. Compounding the difficulty, the trees were knocked over as they were shutting down for the winter, when what growth they still maintained was approaching a seasonal low.

In effect, Kew’s nursery staff had to try to persuade many plants to ignore the signals of age and seasonal change. Staniforth took several of the rarest plants, however, and decided that “the plant was ready for a winter—right, we’ll let it have a winter.”Winter in this case occurred in one corner of a refrigerator room, where about thirty packages of twigs and branch tips were stacked. “It’s like keeping lettuce in a fridge,” Staniforth says. “We wrap the cuttings in damp newspaper and place them in plastic bags. The material will keep for up to six months, lying dormant.”

The delay gave Kew time enough to acquire plants for root stock. Staniforth hopes to save an extremely rare Syrian apple tree by grafting, and is trying to propagate the only male osage orange Kew possesses. Some species cannot be grafted, so Staniforth is attempting to root some cuttings in soil—an effort, basically, to convince the plants that spring has come; several have put up some shoots. In all, Staniforth is making special efforts to save about fifty plants.

Finally, Kew is taking advantage of its special expertise in a new technique to save plants for which conventional propagation methods hold little promise. Using the tools of biotechnology, Kew’s micropropagation unit is trying to raise young plants from tissue cultures. Trees with very hard or pithy wood have resisted conventional propagation techniques—they had to grow from seed or, up until now, they didn’t grow at all.

The goal of micropropagation is to take a culture of the plant—just a piece of tissue—and produce a whole plant that can be grown and eventually placed in the garden. Doing that requires careful manipulation of growth regulators in the culture medium, and it requires good starting stocks—cells that are still young and dividing regularly. Unfortunately, the timing of the storm meant that most of the shoot and bud cells had shut down. “We try and force material to divide,” says Michael Fay, the micropropagation supervisor. “We place the shoots in a sugar-rich solution to break dormancy—it’s worked with some plants here.”

However, the technology is still new and is not always successful. A Kentucky coffee tree that was once spectacularly formed seems to be doing well. A sweet chestnut and the only specimen in England of a southern buckthorn from the United States may also ultimately return to the garden. But even if each attempt succeeds, the microprogation unit will produce clones of no more than fifty of the trees destroyed by the storm—a number of them trees that Staniforth is also working on. Only sixty or seventy trees out of the 500 down, then, will be replaced by genetically identical specimens.

In other words, Kew will be abandoning more than 85 percent of the trees lost in the storm. Over the next decade the missing trees will be replaced by new plants, selected according to criteria most of the dead trees could not meet. Most of those trees had been residents of Kew for a century or more, and had been collected in an age whose standards were different from our own; they are being sacrificed now to the demands of modern scientific precision.

THE SCIENTIFIC PROGRAM at Kew includes several lines of research. One is classical botany, the attempt to characterize plants and their life cycles in detail, and to connect what one sees in a particular plant grown under controlled conditions—its shape, its color, its response to conditions of weather or soil, its rate of growth, its vigor, and so on—w-ith what one knows about that kind of plant in the wild. The storm has given an additional spur to several other lines of research. One of these is biochemistry, which has assumed great importance in recent years: the chemicals that plants produce in seed, leaf, bark, trunk, and root have all been studied intensively. The storm has provided researchers with a major new source of root material to analyze. Roots process all kinds of substances for a plant; verylittle is known about how they do it or about what possibly useful chemicals may be involved. Tree-ring research is another line of inquiry, pursued worldwide; ring growth patterns in Kew’s now greatly enlarged collection of wood show, for example, the impact of the Industrial Revolution on London’s environment.

The essential precondition for any of this work is that every plant examined must possess a meticulously kept pedigree. Thus Staniforth and his staff of five spend a quarter of their time in the nursery simply maintaining the records that track each plant from its source to its eventual presentation as a full-grown specimen in the gardens. These records preserve the details of where the original stock was collected, what part of the plant’s range it comes from, how it was propagated, and under what conditions it grows at Kew. These details sound basic, but this is the data that makes Kewfunction as something other than an ornamental garden. “So little is actually know-n about plants,” Staniforth says, that “any information is gratefully received.”

(By these scientific standards even ordinaryplumbing accidents can have a dire effect. In 1987 Kew also suffered from a flood, in the basement of one of the buildings housing its collection of dried plants. The plants bobbed safely in their plastic bags, but their labels floated off; to botanists, an unlabeled plant specimen is almost no specimen at all.)

A plant that comes complete with the right level of detail—usually the first collected specimen to be rigorouslycharacterized—can form what is called a type specimen. A type specimen need not be typical—an apple tree native to Syria may look considerably different at Kewfrom the way it would in the wild— but it is the yardstick against which to check whether or not another plant (in a garden, in the lab, or in the wild) is of that species. Type specimens, and by extension every plant in a research collection, create the essential context for the conduct of science: material, ail from one source, for experiments that can be repeated, varied, and checked by others.

KEW’S GOALS HAVE changed repeatedly since the gardens were established, two and a quarter centuries ago. Kewbegan as a royal garden, the hobby of a princess. But it was founded during the creation of an empire, and from the mid-nineteenth centuryon, Kew acted as the headquarters of a network of gardens throughout Britain’s tropical possessions, devoted to the cultivation of commercial plants. It was, if you will, one of the first national laboratories. Kew and its satellite gardens studied the horticulture of rubber, coffee, tea, bananas, and the like.

Once the empire was up and running, however, Kew’s role became redundant—any further work on tea, say, could best be done in the mountains of Ceylon or Darjeeling, not in London. Accordingly, by the 1930s Kew had become a refuge for botanical curiosities, collected by peripatetic English naturalists. Under a series of old masters of landscaping, from Capability Brown to William Mesfield to J. D. Hooker, Kew gained the beautiful form as a garden that it has largely retained—at a significant cost, as twentieth-century science would reckon it. Ian Beyer, Kew’s deputy curator, says, “Kew began to go wrong in the twenties. The garden had been designed by eminent people, and for fifty years or so, everyone was afraid to touch their work.”

Instead of continuing to build the scientifically important collection, Kew began to grow what Bevcr calls “botanicalgarden flora”—material traded back and forth between gardens. Thus every garden in Europe might possess specimens propagated from one particularly admired plant. By the late 1960s, as a consequence of neglect and of the deliberate decision to raise plants about which little more was known than that they looked good, Kew and many other gardens were virtually useless as scientific institutions. Charles Erskine, the head of Kew’s arboretum, estimates that even today, after two decades of catching up, more than half the trees under his care are of unknown origin, and are thus essentially irrelevant to a scientist.

Under normal circumstances this state of affairs would persist for some decades: one thing you can’t do in a botanical garden, Beyer says, is “go through the arboretum and cut down the trees you don’t like—even when you know that they have very little scientific validity.”Given that a tree may stand for 150 years or more, this ethical delicacy has meant that change comes very slowly— Kew has been replacing at most sixty to eighty trees a year since the drive began to re-establish its arboretum as a scientific resource. In this context the storm, though it made an unholy mess, is not quite the disaster it originally seemed. The trees that died and will not be repropagated yield to Kew the invaluable gift of space and the opportunity to cultivate the plants that its current curators choose—ones that will serve particular intellectual goals framed now, rather than two or three generations ago.

To GATHER NEW plants Kew mounts an expedition about every other year. Like the rest of the gardens’ operation, the arrangements for such journeys have been changing. In the past the strategy was to go to an interesting place and grab anything that caught one’s eye. Now, with a shift toward greater specialization, Kew and other botanical gardens wall have to cooperate.

Kew, given its particular climate and geographical conditions, can grow’ just about any tree, plant, or shrub that thrives in a temperate zone. Kew’s curators are planning an expedition to China

and would like to go to Argentina, two regions whose flora are already familiar to the gardens’ staff. But the strategy— to concentrate on specific groups of plants—and the decisions about where to go contain a surprise: Kew will not seek out exceptionally rare plants to conserve. If a plant is truly endangered, Beyer argues, the chances of re-establishing a population from botanical-garden stocks once the wild type has become extinct are almost nil; the same forces that knocked the species out once will do so again. Most members of the botanical community share this view.

In this argument a living collection should not be a kind of antiquarian museum, filled with curiosities that have nowhere else to go. Beyer and his colleagues wish to create a garden whose plants will yield knowledge likely to have benefits relevant to human needs. “I look at Ethiopia, or the Sudan,” Beyer says, “and I see we are injecting a lot of money and food, and for what?

I hey need firewood, fodder—they need irrigation. A botanical garden ought to work on the plants of economic importance.”

The protection of species follows from this line of action—but only indirectly. The more work one does, the more one finds important economic implications in the research, which in turn create incentives to protect species. As a consequence, countries that possess the greatest reserves of plant species will tend to conserve the habitats essentia! for the survival of those species—or so the world hopes. However, once botanists make the commitment to gather information about plants in a scientifically rigorous fashion, the choice of which specific plants to preserve and study is more a political one than a scientific one.

The argument is about emphasis. Everyone concedes that gardens that own rare plants should maintain them, but the choice of which new plants to seek out is central to the definition of what a botanical garden ought to do—and here at Kew the choice is unequivocal.

One day two months after the storm one of Kew’s gardeners walked a visitor down the Broad Walk, an avenue marked by the stately progression of pairs of tulip trees, planted in 1939. The trees are purely ornamental; they have no particular importance to any botanist.

The storm destroyed several of them— perversely, usually one of a pair, not both.

No decision has been made about whether to replace the missing halves of pairs, replace whole pairs, or replace the whole avenue, perhaps with a different kind of tree. Ultimately, the Kew collection will be more significant than it was before the storm, with or without the tulip trees. But however Kew’s gardeners repair the damage along the Broad Walk, their approach to the problem is emblematic of the process of thought they now bring to bear at Kew. Formerly the Broad Walk, when the trees were in flower, was a place of stunning beauty. “It is going to take a long time to recapture that,” Charles Erskine said— but the Broad Walk will eventually become complete again in one form or another.

Erskine added, “We reap the benefit now of what our predecessors did. I won’t see what I do; my children’s children will.”

— Thomas Levenson