Fire effects on plant reproductive fitness vary among individuals, reflecting pollination-dependent mechanisms.

Autor: Richardson LK; Program in Plant Biology and Conservation, Northwestern University, 2205 Tech Drive, Hogan 6-140B, Evanston, Illinois, 60208, USA.; Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60022, USA.; Department of Biology, California State University Northridge, 18111 Nordhoff Street, Northridge, Califorrnia, 91330, USA., Beck J; Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60022, USA., Eck DJ; Department of Statistics, University of Illinois, Computing Applications Building, Room 152, 605 E. Springfield Avenue, Champaign, Illinois, 61820, USA., Shaw R; Department of Ecology, Evolution, and Behavior, University of Minnesota, 206 Ecology, 1987 Upper Buford Circle, St. Paul, Minnesota, 55108, USA., Wagenius S; Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60022, USA.
Jazyk: angličtina
Zdroj: American journal of botany [Am J Bot] 2023 Apr; Vol. 110 (4), pp. e16160. Date of Electronic Publication: 2023 Apr 17.
DOI: 10.1002/ajb2.16160
Abstrakt: Premise: Fire induces flowering in many plant species worldwide, potentially improving reproductive fitness via greater availability of resources, as evident by flowering effort, and improved pollination outcomes, as evident by seed set. Postfire increases in flowering synchrony, and thus mating opportunities, may improve pollination. However, few studies evaluate fire effects on multiple components of fitness. Consequently, the magnitude and mechanism of fire effects on reproductive fitness remain unclear.
Methods: Over multiple years and prescribed burns in a prairie preserve, we counted flowering stems, flowers, fruits, and seeds of three prairie perennials, Echinacea angustifolia, Liatris aspera, and Solidago speciosa. We used aster life-history models to assess how fire and mating opportunities influenced annual maternal fitness and its components in individual plants.
Results: In Echinacea and Liatris, but not in Solidago, fire increased head counts, and both fire and mating opportunities increased maternal fitness. Burned Echinacea and Liatris plants with many flower heads produced many seeds despite low seed set (fertilization rates). In contrast, plants with an average number of flower heads had high seed set and produced many seeds only when mating opportunities were abundant.
Conclusions: Fire increased annual reproductive fitness via resource- and pollination-dependent mechanisms in Echinacea and Liatris but did not affect Solidago fitness. The consistent relationship between synchrony and seed set implies that temporal mating opportunities play an important role in pollination. While fire promotes flowering in many plant species, our results reveal that even closely related species exhibit differential responses to fire, which could impact the broader plant community.
(© 2023 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)
Databáze: MEDLINE
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