Even the Soviets have gotten into the global ecology act. After all, Earth Day was a universal project.

To hail its efforts in this "clean up and clear up" campaign, the Soviet Union has issued three stamps and a souvenir sheet titled "Let's Preserve Nature." Each stamp carries an ecological message printed diagonally in the upper left corner and depicts a problem that requires worldwide cooperation.The 10-kopeck stamp, titled "Man, Stop," shows a red rose, half-covered with industrial waste billowing from large smokestacks in the background.

The 15-kopeck, "Man, Save Us," shows a white bird, trapped by industrial waste, attempting to fly into a blue sky.

The 20-kopeck, "Man, Spare Us," features a large tree that has been felled by a circular saw.

The souvenir sheet shows a variety of plants along its margins. In the center of the sheet is a 10-kopeck stamp that portrays a blue swallow building its nest against the side of a factory.

Ecology is not a new theme for the Soviet postal program. A 1983 souvenir sheet was titled "To Preserve Nature and the World"; a 1984 sheet featured the theme "Earth, Nature and its Creatures Are Unique"; and a 1986 sheet was concerned with "Earth - Our Home."

Also appearing on the Russian postal front is a set of six stamps in a continuing series honoring Russian admirals. Each stamp features the portrait of an admiral and the warship he commanded.

The. U.S. Postal Service will release a 15-cent postcard in the Historic Preservation Series that pays tribute to Isaac Royall House in Medford, Mass. The card features a view of the house's main facade. "USA 15" appears in the upper right corner.

The Royall House is considered one of the finest examples of Georgian design in Colonial America and is a registered National Historic Landmark. Originally, the house was a simple brick structure built in the late 17th century by Gov. John Winthrop. In the mid-18th century, the house was bought and rebuilt by Isaac Royall Jr., a wealthy merchant.

When Royall's family fled to England during the Revolutionary War, Colonists confiscated the estate and it became headquarters for Gen. John Stark. Part of the property was later sold to finance the founding of Harvard Law School. In 1908, the Royall House was restored by the Royall House Association.

First-day cancellations are available in two methods. The deadline in either case is July 16.

You can buy the card at a local post office, self-address it and send to: Customer-Supplied Card, Isaac Royall House Postal Card, Postmaster, Medford, MA 02155-9991. No remittance is required. The Postal Service gives preferential service to this type of order.

If you want the Postal Service to provide the card, send, for each card ordered, a peelable, self-addressed label and 15 cents payment in check or money order to: Isaac Royall House Postal Card, Postmaster, Medford, MA 02155-9992.

The Postal Service is springing into action with its Spring 1990 Commemorative Stamp Pack, which features the year's first five commemoratives.

The pack contains mint stamps and text about the Ida B. Wells, Idaho Statehood, Judicial Branch, Love and Wyoming Statehood stamps. The stamps can be displayed behind clear, protective strips on the center panel of the tri-folded pack.

The Stamp Pack (Item No. 8909) is available at most post offices and by mail. Mail orders should include a check or money order for $3.95, plus 50 cents for handling per total order. There is a minimum mail order of $10, which may be reached by ordering other philatelic products or postage stamps. Send orders to: Spring 1990 Commemorative Stamp Pack, Philatelic Sales Division, Kansas City, MO 64144-9997.