Abstract Detail

Ecological Section

Hawkins, Tracy S. [1], Meadows, James S. [2], Williams, Justin P. [1].

Masting periodicity and fate of acorns for Quercus pagoda in four silvicultural treatments: 7 year results.

Masting periodicity and acorn fate in bottomland hardwood forests in the southeastern United States is not well understood, and empirical studies investigating this aspect of oak reproductive ecology for this forest type are scant. In light of this, a long-term study was established to monitor acorn production and fate of acorns for Quercus pagoda (cherrybark oak) trees growing in a bottomland forest concurrent with silvicultural treatments applied in a completely randomized experimental design. Data were collected in 2006 (pre- thinning) and 2009 – 2015 (post-thinning). Acorns were collected in seed traps placed beneath randomly selected Q. pagoda trees and harvested from traps at regular intervals throughout each year. Acorns were counted and categorized as immature, insect predated, avian/mammal predated (pre-dispersal), empty, or viable (sound). There were no differences among control and thinning treatments in mean annual number of acorns produced, nor proportions of acorns in each acorn fate category. Total acorn production varied between years, ranging from a low of 94 ± 18 acorns/m² in 2006 to a high of 201 ± 21 acorns/m² in 2010. Masting periodicity was characterized by successive years of high mast, preceded and followed by low mast years. The proportion of total acorn production dispersed as immature was consistent between years (25 ± 1%), and thus the proportion of acorns reaching maturity did not differ between years. Mammal/avian predation varied between years and was weakly related (R² = 0.1214) to total hard mast. The number of mature acorns predated by Curculio sp. (acorn weevil) and Callirhytis sp. (gall wasp) larvae varied between years and was moderately related to total mature acorn production (R² = 0.3381); however, the proportion of mature acorns predated declined with increased total mature acorn production, suggesting potential for predator satiation during high mast years. A model of Q. pagoda acorn production dynamics for this bottomland forest will be presented, and the importance of high mast years to potential for oak regeneration and provision of quality forage for wildlife will be discussed.

1 - USDA - Forest Service, Center For Bottomland Hardwoods Research, Box 9681, Mississippi State, MS, 39762, USA
2 - USDA - Forest Service, Center For Bottomland Hardwoods Research, P.O. Box 227, Stoneville, MS, 38776, USA

Keywords:
cherrybark oak
forest management
oak reproduction
masting periodicity
Curculio sp.
oak ecology
forest ecology
red oak acorn production.

Presentation Type: Oral Paper:Papers for Sections
Session: 52
Location: Salon 6/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 4:15 PM
Number: 52010
Abstract ID:813
Candidate for Awards:None