Management Implications of Acorn Production

Of the major extrinsic factors (weather, insects, and wildlife) that limit acorns available for regeneration, none is very amenable to management in the general forest setting. Weather variables have the potential to reduce or completely eliminate an acorn crop in a given time and place, however, there is no realistic means of managing weather factors (Beck, 1993).

Insects are potentially very damaging to the acorn crop at many stages of the production process. Numerous insects feed on foliage of oaks. Their impact on acorn production has not been assessed. But such insects as aphids have been shown to have large impacts on nut production in species such as pecans by depleting available energy. It has been hypothesized that premature abscission of flowers may be related to leaf hoppers. It has been observed repeatedly that weevils destroy 50 percent of mature acorns on an average. Experience with seed orchards and seed production areas for the southern pines demonstrates the possibilities for control of insects when an economic demand exists. However, the technical base does not exist for the oak species even if the demand were there (Beck, 1993).

It is technically possible to reduce animal predation by reducing or excluding animal populations. But in a forest setting it is probably not ecologically desirable or politically possible to reduce populations. In fact, mast production specifically for wildlife may often be a management objective. It is probably possible to reduce animal predation in seed orchards; but even there, reducing losses to wildlife will not be a major way to increase acorns available for regeneration (Beck, 1993).

Maintaining the good acorn producers in the stand in a dominant position is currently the only practical way to enhance acorn production. The large inherent differences among trees in productive capability have been observed and reported numerous times over the past 50 years. But this knowledge has not been applied due to the difficulty in identifying acorn producers. Given the many other factors that may impact production in a given year, identification of consistent producers is not easily accomplished. Nevertheless, attempts should be made to identify and manage trees capable of producing large acorn crops (Beck, 1992).