A temporary truce has been reached in an angry dispute over a D.C. recreation department plan to spend $380,000 modernizing a park next to Lafayette Elementary School.

The compromise was approved at a meeting of more than 100 residents of the quiet Chevy Chase neighborhood recently. The gathering, packed with opponents to the modernization, concluded with the adoption by Advisory Neighborhood Commission (ANC) 3G of a plan hammered out before the meeting began. The commission had been asked by the recreation department for advice on the renovation.

The dispute centers on a 12-acre neighborhood park with grassy slopes and quiet corners shaded by giant trees.

The modernization plans call for cutting down some of the locust and mulberry trees; installation of 89 mercury vapor lights for security purposes; construction fo a 16- by 40-foot handball and paddle tennis wall; installation of 4,000 square feet of chain link fence; pagvement of 15,000 square feet of grassy areas; a fenced "tot lot" for small children and nature study area; installation of picinc tables, barbecue grills and lighted baskeball courts; additional horseshoe pits and shuffleboard courts; a row of cherry trees to be planted across a sledding slope, and the construction of a 16- by 16-foot Victorian gazebo.

The plan's supporters are city officials and the Lafayette School Modernization Committee, a group of parents, teachers and school officials who have worked for th past five years on the $4 million renovation of Lafayette Carolyn Harwood, who maintains that the park is primarily a recreation facility heavily used by school groups who need a safe and modern place to play.

The opponents - Friends of Lafayette Park and Playground - are led by Mary Ann Fiske and Brock Evans, neighborhood residents who say they did not hear about the renovation plans until this year. Many members are parents of Lafayette pupils, Fiske said. They argue that the planned ball courts, fences, lights and paving will ruin the park's tranquil beauty and its special character as a quite refuge for neighborhood residents. Also, they believe that the city does not have funds to maintain the expensive new facilities. They want to keep the status quo, with outlays only for necessary repairs of present structures and the elimination of one-unsightly and unsafe play area.

The recent meeting climaxed weeks of acrmmonious exchanges between the neighborhood groups, who were finally brought together in a special task force to settle their differences. The 3 1/2-hour meeting was chaired by Albert Gollin, head of ANC adopted a resolution that Gollin had drafted ahead of time. It supported compromises arrived at by the task force, taking into account a modified plan presented by the Modernization Committee, one of the parties to the dispute. The modified plan watered down the compromise agreement, according to one ANC commissioner.

The propriety of Gollin's role was questioned at the meeting by a neighborhood resident who accused him of conflict of interest. From 1972 to 1976, Gollin was chairman of the Lafayette School Modernaization Committee, and deeply involved in drawing up the plan. Gollin resigned from the committee last year to run for the ANC position.

At the meeting's end, Gollin made a public pledge to consult with both Harwood and Fiske before making written recommendations on behalf of the ANC to the recreation department.

Parts of the task force compromise still in effect apparently are the elimination of additional shuffleboard and horseshoe pits, and some barbecue grills. Being restudied are decisions concerning the destruction of trees, as well as the placement of new trees, lighting of the park and basketball courts, and the location of the tennis wall and gazebo.