The spatio‐temporal distribution of pollen traits related to dispersal and desiccation tolerance in Canarian laurel forest

Nogue, S; Nascimento, L de; Graham, L; Brown, LA; Gonzalez, LAG; Castilla-Beltran, A; Penuelas, J; Fernandez-Palacios, JM; Willis, KJ

Abstract

Questions
Pollen traits (e.g., size, wall thickness, number of apertures) have been suggested to be relevant in terms of pollination mechanisms and the ability of the male gametophyte to withstand desiccation. We examined the spatiotemporal distribution of pollen traits related to dispersal (ornamentation and dispersal unit) and desiccation tolerance (wall thickness, presence of furrows and pores and pollen size). Specifically, we address two questions: how are the pollen traits distributed in relation to different levels of aridity? And, how did the pollen trait composition change with changing past environmental conditions?

Location
Laurel forests of La Gomera and Tenerife (Canary Islands).

Methods
We used pollen rain from 19 forest plots on an elevational gradient of 1050 m and all laurel forest types (cold, dry, humid and ridge crest) to quantify pollen trait composition using community-weighted means. In addition, we used fossil pollen to examine the composition of pollen traits over 9600 years in response to known intervals of regional past climate change.

Results
Our results demonstrated increased prevalence of desiccation tolerance-related pollen traits over drier areas of the laurel forest distribution. We also found increased prevalence of rich pollen grain ornamentation in the core of the laurel forest distribution. Holocene pollen functional diversity increased during a trend towards drier conditions as did the proportion of pollen grains with apertures and thicker walls to indicate desiccation tolerance.

Conclusions
Our study provides the first step towards understanding the role of pollen traits when quantifying the dynamics of different plant communities.

• Journal Article Type: Article
• Acceptance Date: Aug 5, 2022
• Publication Date: Aug 25, 2022
• Deposit Date: Oct 28, 2022
• Publicly Available Date: Oct 28, 2022
• Journal: Journal of Vegetation Science
• Print ISSN: 1100-9233
• Electronic ISSN: 1654-1103
• Publisher: Wiley
• Volume: 33
• Issue: 5
• DOI: https://doi.org/10.1111/jvs.13147
• Publisher URL: https://doi.org/10.1111/jvs.13147
• Additional Information: Funders : British Ecological Society research grant;S.N. Spanish Ministry of Science;J.P. Catalan government grant;J.P. Fundación Ramón Areces grant ELEMENTAL-CLIMATE, J.P. Natural Environment Research Council; Grant Number: 4365/5337; Grant Number: PID2019-110521GB-I00; Grant Number: SGR2017-1005; Grant Number: (NERC) (NE/T009373/1)