My original query:
The classic examples of populations that cycle, including predator-prey
interactions, and some host-parasite interactions, all involve animals.
Are there similar examples of cycles in plant populations? Certainly
lots of variation in abundance, such as in population size of desert
annuals responding to precipitation, but what about regular (cyclic)
variation?
David Inouye
Thanks to all of you who responded (the first few were on ECOLOG-L, and
the others were sent privately):
El 06/02/2017 a las 14:57, Menges, Eric escribió:
Cycling in plants is probably best known for semelparous, strict
biennials. These plants are rosettes one year and flower the second
year. The rosette population is likely to be much larger creating
cycling of total population size for that cohort (e.g. the cohort
flowering in even years). Some populations may have two cohorts but if
disturbances that create recruitment opportunities occur over large
areas, then the population may be dominated by a single cohort and have
biennial cycling.
My research group has documented similar patterns for an annual plant
(Warea carteri) with delayed recruitment in an article in Population
Ecology (2011, volume 53, pages 131-142). In this case the biennial
cycles gradually dampen due to some seeds germinating in off-years. The
cycling is usually initiated by fire and subsequent mass recruitment
from a persistent soil seed bank.
Eric Menges
Perhaps the best example is masting in trees.
Pati Vitt
Here a couple of articles published by my group that may be of interest
HERNANDEZ PLAZA E, NAVARRETEL, LACASTA, C. GONZALEZ-ANDUJAR,
JL**(2012)**Fluctuations in plant populations: Role of exogenous and
endogenous factors. Journal of Vegetation Science 23: 640-646**
GONZALEZ-ANDUJAR, JL, FERNANDEZ-QUINTANILLA, C.; NAVARRETE, L. (2006).
Population cycles in an annual plant produced by delay-density
dependence. /American Naturalist/168: 318-322.
Jose
--------------------------
Dr. José L. Gonzalez-Andujar
Instituto de Agricultura Sostenible (CSIC)
Córdoba (Spain)
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You know about the pseudo-cycle in dipterocarp flowering ... see Ashton,
Givnish, and Appanah 1988 American Naturalist; multi-year
phenomenon driven by El Niño cycles.
AS Watt talked about a microsuccessional cycle in Festuca-dominated
grasslands near the North Sea in Breckland, starting with bare ground
stabilized by pebbles, invasion by Festuca, vigorous growth of Festuca
driven by the capture of fine sand and silt by the growing rosette, a
mature phase of slow growth once the rosettes and mounds poke up too
high, invasion by bryophytes, increasing cover and nutrient-lockup by
bryophytes, Festuca death, wind blowing away silt mound no long
stabilized until a desert pavement re-establishes itself. There were
some publications on this from 1946 to 1960, but I don't know if he ever
characterized the length of the cycle. The proportion of the landscape
in different stages did change, however, apparently in response to
ecological conditions.
A similar story has been told about Larrea-Opuntia cycles, with Larrea
being the Festuca character and Opuntia being the bryophytes character.
Most likely the highly spatially patterned strings and flarks of
patterned peatlands also have an underlying temporal cycle as the
patterns move upslope. Ditto tiger bush in semi-arid areas of Africa,
Australia, and the Chihuahuan desert.
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I don't think the cycles are clock-like – not that PP cycles must be,
depending on the nature of the interactions – but clearly white spruce
and the spruce budworm do something like cycle. Key, as with other
high-latitude systems that cycle, IMHO, is low diversity and thus few
alternative prey or predators. Fires and pines, eucalyptus, etc.
"cycle" to a certain extant.
It seems to me that Flor did some classic work on the cycling of
resistance genotypes in Australian flax, driven by different strains of
a rust.
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One of the things I noticed when I worked on a coastal bluff native grassy-rocky headland is that the
native blue lupins seemed to have "boom" & bust years as a population, possibly in a 3 yr
cycle tho this may not be equivalent to the typical predator. I noticed the pattern when I was doing
multiyear demography studies of Silene douglassii var. oraria on the bluffs. The "best" years
for Silene appeared to be those when not overtopped by lupines growing in the same environment.
I presumed it had to do with the lupine life history cycle.. and life span, but
of course don't know whether anyone has looked at selective factors related to
it. I do know some lupine species are subject to lots of herbivory by mice, or
in other lupines, butterfly larvae, .. but don't know if mice are a seed
predator at the site I worked at.
Better documented cyclic patterns might be some of thoseJonathan Silvertown describes in Chpt. 4 of
his "Demons in Eden", i.e. that can involve demographic components as well as biotic
factors, e.g. Dwarf sisal bamboo and mice, but also the "fir waves" which have
demographic, abiotic and biotic components and are fascinating. Whether you consider any of these
equivalent to animal predator-prey or not, the chapter is a great read if you've not seen it and
students enjoy learning about it. I've not taken time to read actual journal articles on these but
I'm sure others have.
Or perhaps you've hiked Mt Shimagare in Japan and have seen some of these
phenomena. Would love to go there someday.
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Bamboo mass flowering and then death? That's pretty cyclical and
impressive from what I've read.
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spruce/fir waves? but that's not intrinsic to the plant population itself.
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There are some examples of natural cycling of plant populations caused
by overcompensating density-dependence of competition. The 'classical'
exapmple is Symonides, Silvertown & Andreasen, Population Cycles Caused
by Overcompensating Density-Dependence in an Annual Plant, Oecologia
71(1), 1986, 156-58. See also e.g. Freckleton, Watkinson, Are weed
population dynamics chaotic? Journal of Applied Ecology 39 (2002), 699–707.
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Would you consider masting to be cyclic variation? Southern bamboo
species have spectacular synchronized mast events (with 12-, 13- and
30-year cycles for some species). I suppose that most of these cycles do
generate responses in the animals that depend on the resource.
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It isn't biotic like the animal examples, but there is the
grass-clover-filaree pattern in California
grasslands...http://ucanr.edu/sites/UCCE_LR/files/180538.pdf
It is the result of variation in fall precipitation timing and
temperatures. See also Stromberg et al. "California Grasslands" book
including Page 158 of the attached pdf.
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Plants with stand level dieback e.g. Metrosideros polymorpha
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--
Dr. David W. Inouye
Professor Emeritus
Department of Biology
University of Maryland
College Park, MD 20742-4415
[email protected]
Principal Investigator
Rocky Mountain Biological Laboratory
PO Box 519
Crested Butte, CO 81224
