Twenty Years of Natural Loblolly and Shortleaf Pine Seed Production on the Crossett Experimental Forest in Southeastern Arkansas

Abstract

Loblolly and shortleaf pine (Pinus taeda L. and P. echinata Mill., respectively) seed crops were monitored for 20 consecutive years (1980-1981 through 1999-2000) using seed-collection traps in natural stands on the Upper Coastal Plain of southeastern Arkansas. Each seed-collection period began on October 1 and continued through the end of February of successive years. Sound seeds were separated from void seeds by use of a cut test. During 20 yr, sound seed production ranged from O to 2,000,000/ac. There were six bumper seed crops (>800,000 sound seeds/ac), nine good seed crops (40,000-800,000 sound seeds/ac), and five poor seed crops (<40,000 sound seeds/ac). Because no poor seed crops occurred back-to-back, the seed supply was adequate for successful natural pine regeneration over the entire monitoring period. During 8 yr of adequate seed production, when weekly seed counts were made, seed dispersal always peaked in early November; therefore, site preparation should be completed before November to maximize seedling catch.