Why pollen-atmosphere interplay matters to forest gene conservation

Abstract

Forests are thought to adapt too slowly to anthropogenic climate change, making them highly vulnerable to large-scale loss. Losses can accrue swiftly because generations are lengthy, particularly at higher latitudes (>23⁰ to 73⁰) where wind-pollinated forest species are commonly found to mature slowly. Losses incurred during adaptation to climate change translates into less allelic richness, or genetic diversity, and one can expect some resilience on this point because forests have more genetic diversity than other seed plants and this feature has shaped the forest fragmentation paradox debate (Bacles and Jump 2011, Kramer et al. 2008, Lowe et al. 2015). These great reservoirs of genetic diversity in forest trees have an overlooked dimension: temporal layering. To explain temporal layering of genetic variation, consider that a given pollen pool is available to any year’s cohort of ovules is shaped by weather conditions during pollen release, transport and deposition (Box 1). Seed and pollen dispersal occurs on far greater distances than once thought (e.g., Ehrlich and Raven 1969, Williams 2017). Seed from that one ovular cohort will thus have an allelic composition distinct from other cohorts. Shaped by weather conditions occurring pollen release, transport and deposition, the pollen pool is a function of certain atmospheric events3 (Lanner 1966).

Parent Publication

• Gene conservation of tree species—banking on the future. Proceedings of a workshop.

Citation

Williams, Claire G. 2017. Why pollen-atmosphere interplay matters to forest gene conservation. In: Sniezko, Richard A.; Man, Gary; Hipkins, Valerie; Woeste, Keith; Gwaze, David; Kliejunas, John T.; McTeague, Brianna A., tech. cords. 2017. Gene conservation of tree species—banking on the future. Proceedings of a workshop. Gen. Tech. Rep. PNW-GTR-963. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 72-73.