Revisiting the relationship between common weather variables and loblolly-shortleaf pine seed crops in natural stands

Abstract

Seed production was monitored during 24 years using seed-collection traps in loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands located in southeast Arkansas, north-central Louisiana, and southwest Mississippi on the southeastern Coastal Plain, USA. Sound seed production was correlated with mean monthly precipitation and temperature from National Oceanic and Atmospheric Administration weather stations located near the seed-collection areas to determine the potential of weather factors in forecasting pine seed crops. Correlations were restricted to three critical periods in the pine reproductive cycle—strobili primordia differentiation, pollination, and fertilization. The most important (P < 0.05) variables correlated with pine seed production for combined locations were cumulative precipitation (r = +0.60) during July, August, and September at 27 to 25 months before seed dispersal and mean temperature (r = –0.45) in August at 26 months before seed dispersal. Because multiple environmental factors can negatively impact pine seed development during the two years following strobili primordia differentiation, seed-production forecasts based on weather variables should be verified by on-site cone counts during the summer preceding autumn seed dispersal.

Citation

Cain, Michael D.; Shelton, Michael G. 2000. Revisiting the relationship between common weather variables and loblolly-shortleaf pine seed crops in natural stands. New Forests. 19: 187-204.