Temperature-related sex allocation shifts in a recovering keystone species, Pinus palustris

Abstract

Background: The possible effects of climate change on sex allocation of a species have recently emerged as a topic of interest, relative to population sustainability via natural regeneration. Also, the universality of pollen limitation for reproduction and how climate may influence it in different taxonomic groups remain to be explored.

Aims: The aim of this study was to examine how climate fluctuation may affect sex allocation in Pinus palustris.

Methods: We used a long-term observational data on P. palustris (1957–2014), including pollen, female conelets and cone production.

Results: We found that, unlike cone production with its ca. 3-year cycle, (1) pollen (male) and unfertilised conelet (female) production did not exhibit any temporal cycles, (2) pollen and unfertilised conelet production showed lower variation than cone production, (3) pollen and unfertilised conelet production were positively correlated to one another and to final cone production, (4) an optimal male-to-female sex allocation ratio exists for promoting cone production and (5) sex allocation ratio was positively correlated with temperature.

Conclusions: Our findings shed new light on both the reproductive ecology and management of P. palustris ecosystems under changing climates (e.g., through alteration of pollen density and thus the resulting sex allocation).

Keywords:

• climate change
• cone production
• sex ratio
• life cycle
• longleaf pine
• long-term study
• pollen limitation
• regeneration

Acknowledgements

We thank many individuals who assisted with collection of the pollen and cone data and Marilyn Buford, James Barnett and Juan Arroyo for constructive comments which improved this manuscript. X. Chen was partially supported by USDA National Institute of Food and Agriculture McIntire-Stennis project 1008643.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed here.

Additional information

Funding

None.

Notes on contributors

Qinfeng Guo

Qinfeng Guo is interested in community ecology, biogeography and invasion ecology.

Dale G. Brockway

Dale G. Brockway is a research ecologist interested in forest ecosystem ecology, fire ecology, restoration ecology and silviculture.

Xiongwen Chen

Xiongwen Chen is interested in landscape ecology using field information, ecological analysis and modelling, remote sensing and GIS for basic ecological and forestry research.