Reproductive dynamics of four plant communities of southwestern British Columbia

Pojar, J.

doi:10.1139/b74-234

Cited by 113 publications

(99 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Obligate outcrossing species tend to flower longer than autogamous or self-compatible species (24,195), and this may reflect the greater uncertainty of pollination. Extended duration could also allow individuals to track and accumulate resources needed for seed maturation in environments where resources are either temporally unpredictable or sparse (24).…”

Section: Duration Synchrony and Skewness Within Speciesmentioning

confidence: 99%

Phenological Patterns of Terrestrial Plants

Rathcke¹,

Lacey²

1985

Annu. Rev. Ecol. Syst.

1,308

680

View full text Add to dashboard Cite

The term phenology is derived from the Greek word phaino meaning to show or to appear. Hence, phenology is defined as the study of the seasonal timing of life cycle events. For plants the seasonal timing of such events can be critical to survival and reproduction. In agriculture the most common failure of introduced crops is the inability to adjust to the seasons imposed by the new, environment (68). In the past few years, interest in the ecology and evolution of timing of life cycle events has grown. Here we review the literature on phenological patterns of germination, flowering, and fruiting (including dispersal).The phenological pattern of any life cycle event can be quantitatively defined as a statistical distribution characterized by such parameters as time of occurrence (onset, mean, mode), duration (range), synchrony (variance), and skewness. For each life cycle event we discuss each parameter for which data are available. Because parameters at one level can contribute to parameters at higher levels, parameters are sometimes related. For example, the degree of synchrony within and among individuals can determine duration at the population level. Therefore, we discuss phenological patterns at the levels of individuals, populations, species, and communities. Also, we use the word phenology in its strict sense of seasonal timing within years; and we address variation among years only when it pertains to the discussion of within-year patterns.The purpose of this review is to present hypotheses about possible evolutionary causes and consequences of different phenological patterns and to discuss the evidence for each hypothesis. We also briefly summarize information about the environmental and genetic controls of timing because these are the proximate factors that can influence the evolution of phenological patterns. We divide our review into four sections. The first three address germination, flowering, and fruiting separately. Each section covers possible selective factors, proximate environmental cues, and genetic determinants of different phenological parameters. The last section focuses on the relationships of germination, flowering, and fruiting, to the whole life cycle of the plant. Here we address possible ecological and evolutionary constraints that may direct the evolution of all life cycle events.Space prevents an exhaustive literature review, particularly of descriptive studies, so we mention representative studies and reviews that provide the reader access to additional literature. We do not address phenological patterns of leaf production (43,146) or the specific methodologies for collecting and analyzing phenological data (151, 194, 20 1). GERMINATIONThe seedling stage is the most vulnerable time in the life cycle of a plant (10 1). Mortality is often severe because small seedlings have minimal capacity for homeostatic responses or physiological retrenchment in the face of unfavorable abiotic or biotic conditions (10). Therefore, the timing of germination should be under strong selection to occu...

show abstract

Section: Duration Synchrony and Skewness Within Speciesmentioning

confidence: 99%

Phenological Patterns of Terrestrial Plants

Rathcke¹,

Lacey²

1985

Annu. Rev. Ecol. Syst.

1,308

680

View full text Add to dashboard Cite

show abstract

“…Although many recent papers have dealt with pollination ecology at the community level (Hocking, 1968;Keven, 1972;Frankie et al, 1974;Pojar, 1974;Heinrich, 1976;Schmeske et al, 1978;Parrish & Bazzaz, 1979;Opler et al, 1980;Arroyo et al, 1982;Numata & Tanaka, 1982;Tanaka, 1984), only a few studies have referred to populations and individuals comprising the community (Augspurger, 1980(Augspurger, , 1981(Augspurger, , 1983. On the other hand, the morphological correspondence of animal-pollinated flowers with their pollinators has been described in terms of a 'pollination syndrome' (Faegri & van der Pijl, 1979).…”

Section: Introductionmentioning

confidence: 99%

The ecological pollination syndromes of insect‐pollinated plants in an alpine meadow

Yumoto

1986

Ecological Research

View full text Add to dashboard Cite

The insect pollination of an alpine plant community consisting of herbs and shrubs, was observed on Mt. Kisokoma-ga-take, central Honshu, Japan. There were two main groups of pollinators, syrphid flies and bumble bees. Although some shrubs were visited by both types of insects, other shrubs and the herbs were visited by either syrphid flies or bumble bees. Two types of herbs categorized by the difference of flower-visiting insects, the Syrphid-type and the Bombus-type, exhibited some clearly contrasting ecological characteristics such as the flowering behavior of individual plants, spatial distribution of the plant populations and segregation of flowering phenology at the community level. The Syrphid-type herbs were densely distributed throughout wide areas in the tall herb stand, and all the flowers borne by an individual plant bloomed simultaneously. Each species did not markedly segregate its flowering time from that of other species of the same type. The Bombus-type herbs were distributed locally and/or at low density, and the individual flowers borne by an individual plant showed staggered flowering times. Each species had a more strictly segregated flowering time. These ecological characteristics of these two flower types seemed to be related to the behavioral characteristics of their pollinators.

show abstract

“…Flowering duration could determine the total number of flowers produced and thus set an upper limit on the number of ovules and pollen grains produced. A protracted flowering period could reduce the uncertainty of pollination (Wilson and Rathcke 1974;Ackerman 1989;Preston 1991) and act as a means of reproductive assurance which could be critical in pollen-limited obligately outcrossing species (Pojar 1974;Bawa 1983). Thus, selection on flowering duration and number of flowers produced should be directional.…”

mentioning

confidence: 99%

NATURAL SELECTION ON GENETICALLY CORRELATED PHENOLOGICAL CHARACTERS INLYTHRUM SALICARIAL. (LYTHRACEAE)

O’Neil

1997

Evolution

View full text Add to dashboard Cite

The seasonal timing of life-history events such as flowering can be critical to plant reproductive success (Rathcke and Lacey 1985). There is considerable evidence for a relationship between the timing of flowering and fecundity (Schemske 1977;Augspurger 1981;Roach 1986;Mazer 1987), and for selection on timing of initial flowering (Schemske 1984; Stewart and Schoen 1987;Campbell 1989 Campbell , 1991Kelly 1992a). However, the prevalence of phenotypic (Mazer 1987; Dorn and Mitchell-aids 1991; Kelly 1992a,b) and genetic correlations (Dorn and Mitchell-aids 1991; but see Kelly 1993) between the timing of flowering and other life-history events or other quantitative traits makes it difficult to predict how populations might respond to selection acting on flowering time. Many of the traits that can be correlated with the timing of flowering such as plant size, duration of flowering, and the number of flowers produced, are traits that could be subject to selection themselves. A high degree of intercorrelation among characters can make it difficult to disentangle the effects of direct selection from the effects of selection on correlated traits, especially if correlated traits are not included in the selection analysis.Many of the potential problems associated with the interpretation of selection on correlated characters can be ameliorated if the genetic variance-covariance structure of the traits in the population subject to selection is known. Unfortunately, few studies have simultaneously assayed selection gradients, heritabilities, and genetic correlations (but see Kelly 1992aKelly , 1993Campbell et al. 1994). Knowledge of heritabilities allows a prediction of whether the population will respond to selection. Moreover, low additive genetic coefficients of variation (Houle 1992) for characters that are subject to strong phenotypic selection can be interpreted as evidence that selection has eroded genetic variation. The existence of genetic correlations can explain the presence of significant additive genetic variance in the face of strong selection if they act as evolutionary constraints. Knowing both the pattern of phenotypic selection and genetic correlations can allow a much more insightful interpretation of the potential for an evolutionary response to indirect selection via selection on a genetically correlated trait (see Campbell et al. 1994).The study of life-history characters such as flowering time provides an ideal system to understand how selection acts on phenotypically and genetically correlated characters. The degree of flowering synchrony among individuals within a plant population could influence reproductive success by enhancing the ability of individual plants to attract pollinators if attraction is density dependent (Augspurger 1980(Augspurger , 1981Thomson 1980; but see Schemske 1980;Zimmerman 1980;Melampy 1987;Rodriguez-Robles et al. 1992). Plants flowering in synchrony will also have a greater number of potential mates. Thus, stabilizing selection should favor individuals exhibiting flowe...

show abstract

Reproductive dynamics of four plant communities of southwestern British Columbia

Cited by 113 publications

References 9 publications

Phenological Patterns of Terrestrial Plants

Phenological Patterns of Terrestrial Plants

The ecological pollination syndromes of insect‐pollinated plants in an alpine meadow

NATURAL SELECTION ON GENETICALLY CORRELATED PHENOLOGICAL CHARACTERS INLYTHRUM SALICARIAL. (LYTHRACEAE)

Contact Info

Product

Resources

About