Evolutionary Drivers, Proximate Mechanisms, and Spatial Synchrony of Acorn Production in Oaks

Walter D. Koenig, Mario B. Pesendorfer, and Johannes M. H. Knops

Published May 2017 in International Oaks No. 28: 29–40

Abstract

Masting behavior – the highly variable and synchronized production of seeds by a population of plants – is common among oaks and has dramatic effects on resource dynamics and community structure. Based on the California Acorn Survey, our long-term study of acorn production by California oaks, we summarize the major hypotheses driving this phenomenon along with some of the questions remaining to be answered about masting at both the functional (ultimate) and mechanistic (proximate) levels of analysis. We also discuss one of the key issues regarding the definition of masting, namely what constitutes a population. This latter issue has recently been addressed by quantifying spatial synchrony, the spatial and temporal scale at which acorn production is synchronous. The drivers of spatial synchrony differ dramatically depending on the spatial scale of interest; at the relatively small spatial scale of individual trees a few km apart, the primary drivers for one species we have studied in detail, the valley oak (Quercus lobata Née) are local environmental factors such as soil nutrients and water availability, whereas at the large spatial scale of several hundred km the drivers of both differences in overall productivity and spatial synchrony are primarily more general environmental factors, specifically weather.

Keywords

California Acorn Survey, economy of scale, masting, Moran effect, pollination efficiency, predator satiation, resource matching

References

Abe, T., Y. Tachiki, H. Kon, A. Nagasaka, K. Onodera, K. Minamino, Q. Han, and A. Satake. 2016. Parameterisation and validation of a resource budget model for masting using spatiotemporal flowering data of individual trees. Ecology Letters 19: 1129-1139.

Büsgen, M., and E. Münch. 1929. The structure and life of forest trees. Chapman & Hall, London.

Crone, E.E., and J.M. Rapp. 2014. Resource depletion, pollen coupling, and the ecology of mast seeding. Annals of the New York Academy of Sciences 1322: 21-34.

Crone, E.E., E. Miller, and A. Sala. 2009. How do plants know when other plants are flowering? Resource depletion, pollen limitation and mast-seeding in a perennial wildflower. Ecology Letters 12: 1119-1126.

Ellis, W. 1743. Modern Husbandman. T. Osborne and N. Cooper, London.

Isagi, Y., K. Sugimura, A. Sumida, and H. Ito. 1997. How does masting happen and synchronize? Journal of Theoretical Biology 187: 231-239.

Kelly, D., and V.L. Sork. 2002. Mast seeding in perennial plants: why, how, where? Annual Review of Ecology and Systematics 33: 427-447.

Kelly, D., D.E. Hart, and R.B. Allen. 2001. Evaluating the wind pollination benefits of mast seeding. Ecology 82: 117-126.

Kelly, D., A. Geldenjuis, A. James, E.P. Holland, M.J. Plank, R.E. Brockie, P.E. Cowan, G.A. Harper, W.G. Lee, M J. Maitland, A.F. Mark, J.A. Mills, R.P. Wilson, and A. E. Byrom. 2013. Of mast and mean: differential temperature cue makes mast seeding insensitive to climate change. Ecology Letters 16: 90-98.

Knapp, E.E., M.A. Goedde, and K.J. Rice. 2001. Pollen-limited reproduction in4: implications for wind pollination in fragmented populations. Oecologia 128: 48-55.

Knops, J.M. H., W.D. Koenig, and W.J. Carmen. 2007. A negative correlation does not imply a trade-off between growth and reproduction in California oaks. Proceedings of the National Academy of Sciences (USA) 104: 16982-16985.

Koenig, W.D. 2002. Global patterns of environmental synchrony and the Moran effect. Ecography 25: 283-288.

Koenig, W.D., and M.V. Ashley. 2003. Is pollen limited? The answer is blowin' in the wind. Trends in Ecology and Evolution 18: 157-159.

Koenig, W.D., and J.M.H. Knops. 2000. Patterns of annual seed production by northern hemisphere trees: a global perspective. American Naturalist 155: 59-69.

Koenig, W.D., and J.M.H. Knops. 2013. Large scale spatial synchrony and cross-synchrony in acorn production by two California oaks. Ecology 94: 83-93.

Koenig, W.D., J.M.H. Knops, W J. Carmen, M.T. Stanback, and R.L. Mumme. 1994a. Estimating acorn crops using visual surveys. Canadian Journal of Forest Research 24: 2105-2112.

Koenig, W.D., R.L. Mumme, W.J. Carmen, and M.T. Stanback. 1994b. Acorn production by oaks in central coastal California: variation in and among years. Ecology 75: 99-109.

Koenig, W.D., K.A. Funk, T.S. Kraft, W.J. Carmen, B.C. Barringer, and J.M.H. Knops. 2012. Stabilizing selection for within-season flowering phenology confirms pollen limitation in a wind-pollinated tree. Journal of Ecology 100: 758-763.

Koenig, W.D., J.M.H. Knops, W J. Carmen, and I.S. Pearse. 2015. What drives masting? The phenological synchrony hypothesis. Ecology 96: 184-192.

Koenig, W.D., A.R., M.D. Carbonero, P. Fernández-Rebollo, J.M.H. Knops, T.T. Marañón, C.M. Padilla-Díaz, I.S. Pearse, I.M. Pérez-Ramos, J. Vázquez-Piqué, and M.B. Pesendorfer. 2016. Is the relationship between mast-seeding and weather in oaks related to their life-history or phylogeny? Ecology 97: 2603-2615.

Mohler, C.L. 1990. Co-occurrence of oak subgenera: implications for niche differentiation. Bulletin of the Torrey Botanical Club 117: 247-255.

Monks, A., J.M. Monks, and A J. Tanentzap. 2016. Resource limitation underlying multiple masting models makes mast seeding sensitive to future climate change. New Phytologist 210: 419-430.

Moreira, X., L. Abdala-Roberts, Y. B. Linhart, and K. A. Mooney. 2014. Masting promotes individual- and population-level reproduction by increasing pollination efficiency. Ecology 95: 801-807.

Norton, D.A., and D. Kelly. 1988. Mast seeding over 33 years by Dacrydium cupressinum Lamb. (rimu) (Podocarpaceae) in New Zealand: the importance of economies of scale. Functional Ecology 2: 399-408.

Pearse, I.S., W.D. Koenig, and J.M.H. Knops. 2014. Cues versus proximate drivers: testing the mechanism behind masting behavior. Oikos 123: 179-184.

Pearse, I.S., W.D. Koenig, K.A. Funk, and M.B. Pesendorfer. 2015. Pollen limitation and flower abortion in a wind-pollinated, masting tree. Ecology 96: 587-593.

Pearse, I.S., W.D. Koenig, and D. Kelly. 2016. Mechanisms of mast seeding: resources, weather, cues, and selection. New Phytologist 212: 546-562.

Pérez-Ramos, I.M., J.M. Ourcival, J.M. Limousin, and S. Rambal. 2010. Mast seeding under increasing drought: results from a long-term data set and from a rainfall exclusion experiment. Ecology 91: 3057-3068.

Pesendorfer, M.B., W.D. Koenig, I.S. Pearse, J.M.H. Knops, and K.A. Funk. 2016a. Individual resource-limitation combined with population-wide pollen availability drives masting in the valley oak (Quercus lobata). Journal of Ecology 104: 637-645.

Pesendorfer, M.B., T.S. Sillett, W.D. Koenig, and S.A. Morrison. 2016b. Scatter-hoarding corvids as seed dispersers for oaks and pines: a review of a widely distributed mutualism and its utility to habitat restoration. Condor: Ornithological Applications 118: 215-237.

Sánchez-Humanes, B., V.L. Sork, and J.M. Espelta. 2011. Trade-offs between vegetative growth and acorn production in Quercus lobata during a mast year: the relevance of crop size and hierarchical level within the canopy. Oecologia 166: 101-110.

Satake, A., and Y. Iwasa. 2000. Pollen coupling of forest trees: forming synchronized and periodic reproduction out of chaos. Journal of Theoretical Biology 203: 63-84.

Satake, A., and Y. Iwasa. 2002a. Spatially limited pollen exchange and a long-range synchronization of trees. Ecology 83: 993-1005.

Satake, A., and Y. Iwasa. 2002b. The synchronized and intermittent reproduction of forest trees is mediated by the Moran effect, only in association with pollen coupling. Journal of Ecology 90: 830-838.

Sharp, W.M. and V.G. Sprague. 1967. Flowering and fruiting in the white oaks. Pistillate flowering, acorn development, weather, and yields. Ecology 48: 243-251.

Silvertown, J.W. 1980. The evolutionary ecology of mast seeding in trees. Biological Journal of the Linnean Society 14: 235-250.

Sork, V.L., J. Bramble, and W. Sexton. 1993. Ecology of mast-fruiting in three species of North American deciduous oaks. Ecology 74: 528-541.

Sork, V.L., F.W. Davis, P.E. Smouse, V.J. Apsit, R.J. Dyer, J.F. Fernandez-M., and B. Kuhn. 2002. Pollen movement in declining populations of California valley oak, Quercus lobata: where have all the fathers gone? Molecular Ecology 11: 1657-1668.

Stearns, S.C. 1976. Life-history tactics: a review of the ideas. Quarterly Review of Biology 51: 3-47.