A Five-year Record Mast Production and Climate in Contrasting Mixed-oak-hickory Forests on the Mashomack Preserve, Long Island, New York, USA

This five-year study (2007–2011) investigated year-to-year variation in the oak (Quercus spp.) and hickory (Carya spp.) mast production in five different variations of mixed-oak-hickory forests at the Mashomack Preserve on Shelter Island, Long Island, New York. All seven species (six oaks and one hickory) had one to three mast years during the five year study, with black oak (Quercus velutina) having the highest number of mast years and producing the largest number of acorns. Pignut hickory (Carya glabra) had a similarly high overstory importance value to black oak in the study stands but had only one mast year and produced less than half of the nuts produced by black oak. White oak (Quercus alba) was the third ranking tree species in term of overstory importance and mast production, having two mast years during the study. There was a large amount of year-to-year and stand variation in mast production. The highest amount of mast was produced in 2009 and 2010, yet there was a 3–4 fold difference between the least and most productive stands in each year. The year 2011 was unique for having very low mast production and no mast year for any of the six tree species. This is attributed to a significant drought in 2010 that persisted through the summer of 2011. The 2010 drought did not reduce mast production in that year.