The Montgomery County Housing Opportunities Commission has issued more than 300 low-interest mortgages under a special program that started a month ago.

The 30-year, fixed-rate loans, which the commission uses to encourage construction of moderately priced housing, brought to 4,000 the number of single-family mortgages issued by the commission since 1979.

Information about the mortages may be obtained by calling 565-HOME. Autumn Leaf Collection

Autumn leaf collection will begin in Montgomery on Nov. 5 and continue through the first week in January in part of the south county.

The district is bounded by Rte. I-270, Norbeck, Bel Pre and Bonifant roads, Northwest Branch Park, and the District and Prince George's County lines.

Leaves should be placed in piles or containers behind curbs, not in streets or alleys.

Sticks, branches and coarse garden debris should be placed in containers for pickup with regular household trash. Newspaper Recycling Center

St. Paul's Catholic Church in Damascus has opened a newspaper recycling center in its parking lot at 9420 Main St. The center will be open daily from 9 a.m. to 5 p.m.

Proceeds from the program will help youth programs in the Damascus area, according to Barry Levy, who is coordinating the recycling effort. Four Corners Land Values

First, Four Corners in lower Montgomery lost its local elementary school, which closed last year because of declining student enrollments in the neighborhood between Wheaton and Silver Spring.

Then, county officials announced plans to close the community's Northwood High School in mid-1985.

That's when officers of five civic associations in the Four Corners area met with County Executive Charles W. Gilchrist and prompted the county government to sponsor a $2,800 survey of property values there.

The results, issued earlier this month, indicate that despite the school closings, housing values in Four Corners over the past decade remained above the countywide average.

"Many people felt their neighborhood was being drained of public services and that would have an impact on the value of their property," said William Sher, a county housing expert. The property survey, conducted by Real Estate Analysis Inc., instead found that Four Corners fared better than other Montgomery neighborhoods.

The survey of 85 houses found that about half of them showed price gains higher than the county average.

The report noted that property values across the county, when measured in constant dollars, eroded over the past 10 years.