What with the International Sculpture Conference due to open officially here next Tuesday, Washington's galleries and alternative art spaces are already alive with sculpture of every kind. The next few weeks will provide gallery-goers with a unique opportunity to get a taste of contemporary sculpture of every possible school, aesthetic persuasion and material, and from all over the globe.

To begin with, the work of four Washington area artists of very different backgrounds and inclinations have been assembled in a show curated by well-known print collector Joshua Smith and installed in the Columbia Square building downtown. Titled "Washington International Sculpture," it consists of nine works: three by Emilie Benes Brzezinski and two each by Nizette Brennan, Alfredo Halegua and John Ruppert.

While this is an ambitious and largely successful exhibition, Halegua's squat, David Smith "Cubi"-like burnished aluminum works don't work terribly well in the lofty I.M. Pei atrium. Uncomfortably derivative, they are singularly undynamic and placed too close together to compete with the space.

However, the other artists' works come off beautifully, for a number of reasons. Brennan's lovely limestone and steel pieces, "Wicomico") and "The Great Wicomico," have been thoughtfully situated -- one is tempted to say secreted -- to maximize their inherently intimate qualities. The larger of the two, both of which are compositions of essentially the same two scored limestone shapes, has been placed in the half-circular pool at the base of the broad looping stairway leading to the atrium's lower level. The other, perched atop a fluted column, sits in the corner of the landing, so discreetly as to nearly evade detection. It looks as if it's been there all along -- a very nice touch.

Brzezinski's commanding raw wood sculptures do very well in the space too, by virtue of their sheer size and rough-hewn simplicity. This artist's work has always had a rather primal power, and though it looks out of place in the polished chrome and pink marble interior, it looks, paradoxically, perfectly out of place. The imposing but graceful "Poplar Arch," especially, benefits from the location. The massive, highly original cast steel pieces of Ruppert also do very nicely in this environment, bringing as they do a severely masculine, ruggedly industrial flavor to the exhibit. These two darkly towering monoliths -- blackened, filed, welded and distressed -- outright challenge the slickly civilized atrium. The powerful yet oddly graceful "Vertical Barge," with its row of huge shipyard chain-links fused to its face, is a truly memorable piece of work.

David Nash at de Andino British sculptor David Nash has for years worked almost entirely with wood -- not carefully crafted, finished and polished wood, but literally parts of trees: cultivated with green moss and lichen, soaked in water, charred, stacked or rough-sawn into slabs and nearly paper-thin sheaves. He has even planted trees and bushes in patterns to create living sculptures.

Few artists feel themselves and their vocations as closely tied to nature as does Nash, who works out of a studio in an old converted church in an almost treeless slate-quarrying area in Wales. A small but very representative exhibit of his thoughtful and unique sculptures, prints and charcoal studies is currently on view at de Andino Fine Arts gallery. And though Nash's organic works always look just a tad uncomfortable indoors -- as most of them are irrevocably rooted in the out-of-doors environment -- you'll nevertheless get a pretty accurate idea of what he's after from this show.

Nash makes his own charcoal, and has in the past often combined, say, a large work made of charred wood with a drawing of same rendered in the piece's own burnt material. This is another means by which he sustains an intimate connection between his drawings, which are an essentially artificial aspect of the sculptural process, and the natural world with which they deal. And aside from one or two pieces here, such as "Cracking Box," a coarsely doweled, slab-formed crate, and the simple, elegant elm wood form "Drifting Star/Loose Cog," the various studies for outdoor projects are the most satisfying examples of his work.

Especially good are the delightful charcoal and pastel studies of "Four Sheep Spaces" -- a` la Henry Moore -- and the large "Ile de Vassiviere: Summer '89, birch, oak, pine.") The first is a series of studies of natural outcroppings of black stone in Derbyshire, each subtly rendered almost as a cloud, each with what appears to be a small oval pool of brown water at its foot. The second is a whole collection of ideas for outdoor works, a number of which already have been executed on one or more occasions by Nash -- the "Ladders" of thick branches (and sometimes entire trees) joined with rungs, for example, one of which he constructed in Japan several years ago. There is a wonderful whimsy to many of this artist's concepts, and this tempers the intellectual earnestness with which he continually probes his materials for more ways to draw attention to their innate beauty, as well as to create visually stimulating sculpture.

Robert Brady at Mateyka American sculptor Robert Brady also works in wood, but with an artistic agenda totally different from that of Nash's. His formed and painted works, a small number of which are currently on view at Marsha Mateyka Gallery, are more in the nature of ritual petroglyphic figures, like those you might find painted on or graven into the sides of cliffs in the Southwest deserts.

Brady has formerly explored many other techniques and materials, including ceramics, basket-weaving and stone. But these painted wood figures are among his most successful to date. Tall, elongated, sometimes with limbs nailed or wired on like puppets, they have a curiously plantlike presence. In fact, although they are intentionally crafted into decidedly anthropomorphic archetypes, the artist has at the same time given them formal references to organic forms. The tall, lovely "Cirrus," for instance, at first resembles not a human figure so much as a sort of inverted jack-in-the-pulpit, replete with a bulb-topped spadix in the hollow of the figure's boat-shaped back.

Such boat or petal shapes recur throughout Brady's work. In the wall construction "Natal," small versions of this convex ovoid form are used to represent the wings of a host of white "angels" converging about an attached stick figure's head. And the tall, tiny-headed standing figure "Aleut" (whose title gives a clue to the inspiration for some of these works) supports another boat form upright in its arms. Then there are two figures in a distinctly different style or derivation, one sitting, one standing, that seem in some respects more akin to Picasso's carved stick figures or Modigliani's stone carvings inspired by African sculpture. In all, Brady's work investigates the long legacy of figural abstraction, and the many symbolic uses to which it has been put in cultures throughout the ages. In doing so he has arrived at a stylistic synthesis that is recognizably his own.

Washington International Sculpture: Nizette Brennan, Emilie Benes Brzezinski, Alfredo Halegua and John Ruppert, at Columbia Square, 555 13th St. NW, through Oct. 19.

David Nash: Drawings and Sculpture, at de Andino Fine Arts, 1609 Connecticut Ave. NW, through June.

Robert Brady: Recent Sculpture and Drawings, at Marsha Mateyka Gallery, 2012 R St. NW, through June 16.