Effect of acorn burying depth on germination, seedling emergence and development of Quercus aliena var. acuteserrata

Abstract

Acorns of Quercus aliena var. acuteserrata are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6cm-, 12cm- and 18cm-depth. The experimental results show: Fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at a later time than of acorns buried less deeply. They appeared to have more difficulties to emerge aboveground than the seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than late emerged seedlings, seedlings from shallowly buried acorns had an advantage.