Acorn production prediction models for five common oak species of the eastern United States

Abstract

Acorn production varies considerably among oak (Quercus) species, individual trees, years, and locations, which directly affects oak regeneration and populations of wildlife species that depend on acorns for food. Hard mast indices provide a relative ranking and basis for comparison of within‐ and between‐year acorn crop size at a broad scale, but do not provide an estimate of actual acorn yield—the number of acorns that can potentially be produced on a given land area unit based on the species, number, and diameter at breast height (dbh) of oak trees present. We used 10 years of acorn production data from 475 oak trees to develop predictive models of potential average annual hard mast production by five common eastern oak species, based on tree diameter and estimated crown area. We found a weak (R2 = 0.08–0.28) relationship between tree dbh and acorn production per unit crown area for most species. The relationship between tree dbh and acorn production per tree was stronger (R2 = 0.33–0.57). However, this is because larger‐dbh trees generally have larger crowns, not because they have a greater capacity to produce more acorns per unit crown area. Acorn production is highly variable among individual trees. We estimated that dbh of at least 60 dominant or codominant oak trees per species should be randomly sampled to obtain an adequate representation of the range of dbhs (≥12.7 cm dbh) in a given forest area, and achieve precise estimates when using these equations to predict potential acorn production. Our predictive models provide a tool for estimating potential acorn production that land managers and forest planners can apply to oak inventory data to tailor estimates of potential average annual acorn production to different forest management scenarios and multiple spatial scales. © 2011 The Wildlife Society.

Environmental and endogenous drivers of tree mast production and synchrony in piñon–juniper–oak woodlands of New Mexico

“…, Rose et al. ). Our predictive models provide one approach for central New Mexico, although other regions of the Southwest would have to develop area‐specific calibrations of parameters.…”

Seedbanks, germination and early survival of bitter cherry (Prunus emarginata) in coastal British Columbia

“…Conversely, the soil sampling depth of 0-10 cm included most but not all seed (Section 2.1) and may have underestimated seed populations within a stand. The greater seed bank in 51-75 year old stands likely results from tree size and age increasing to a maximum, combined with inputs of animal-dispersed seed, and offset in older stands by decreasing numbers of P. emarginata stems (Lutz and Halpern, 2006), decreasing crown size and potential seed production as mature trees are overtopped (Chapman et al, 1992;Rose et al, 2011) and gradual mortality in the soil seed bank. Contributions of these factors to seed populations in these sites are important, but unknown.…”

Stand Structure and Acorn Production of the Island Scrub Oak (Quercus pacifica)

“…Nevertheless, crown diameter tends to correlate strongly with tree biomass or volume and is increasingly applied in remote sensing studies (Dubayah andDrake 2000, Popescu et al 2011). Furthermore, recent work shows that crown area, estimated from crown diameter, is a reliable predictor of overall acorn production in 5 common oak species of the eastern United States (Rose et al 2012).…”