Summary 1. The concept of plant functional type proposes that species can be grouped according to common responses to the environment and/or common effects on ecosystem processes. However, the knowledge of relationships between traits associated with the response of plants to environmental factors such as resources and disturbances (response traits), and traits that determine effects of plants on ecosystem functions (effect traits), such as biogeochemical cycling or propensity to disturbance, remains rudimentary. 2. We present a framework using concepts and results from community ecology, ecosystem ecology and evolutionary biology to provide this linkage. Ecosystem functioning is the end result of the operation of multiple environmental filters in a hierarchy of scales which, by selecting individuals with appropriate responses, result in assemblages with varying trait composition. Functional linkages and trade-offs among traits, each of which relates to one or several processes, determine whether or not filtering by different factors gives a match, and whether ecosystem effects can be easily deduced

/pdf/predicting-changes-in-community-composition-and-ecosystem-3zopj1ch0s.pdf

Predicting changes in community composition and ecosystem functioning from plant traits: revisiting the Holy Grail

羟氨苄青霉素引起大疱性类天疱疮样疹

Storage is a characteristic feature of most plants, particularly perennials, and the subject has been thoroughly reviewed according to its chemistry and physiology (9, 40, 59, 80, 133, 139). However, in ecology much of the information on storage is based on observation rather than experimentation, and experiments often fail to confirm common perceptions of the nature and dynamics of stored reserves. For example, clipping studies show that not all carbohydrates are available to the plant, even though they are considered to be stored reserves. In this review we suggest criteria for defining storage in ecological and eonomic contexts in order to examine the costs and benefits of storage. We then evaluate the evidence for, and ecological importance of, different types of storage. We discuss storage in relation to vegetative growth

/pdf/the-ecology-and-economics-of-storage-in-plants-2grclrzphb.pdf

The Ecology and Economics of Storage in Plants

A central goal in ecology is to predict population dynamics from demographic information. Based on the asymptotic population growth rate l, calculated from a projection matrix model as a descriptor of the population dynamics, we analyze published data of 49 species of birds to determine how l is influenced by variation in different demographic traits. Across species, the mean elasticity of the adult survival rate was significantly larger than the mean elasticity of the fecundity rate. The contribution of the fecundity rate to the population growth rate increased with increasing clutch size and decreasing adult survival rate, while the greatest contribution of adult survival rate occurred among long-lived species that matured late and laid few eggs. This represents a continuum from ''highly reproductive species'' at one end to ''survivor species'' at the other end. In addition, a high contribution of adult survival rate was found in some relatively long-lived species with early age at maturity (and a large clutch size) which was assumed to represent a bet-hedging strategy, i.e., producing a large number of offspring in some occasional good years. In a retrospective analysis, interspecific differences in the effects of actual temporal variation in adult survival rate and fecundity rate on the variability of l were analyzed. These effects are expected to be large when the variance or the sensitivity of the trait is large. Because there was a negative relationship among species, both for the adult survival rate and the fecundity rate between the variability and the sensitivity of the trait, contribution of a trait to the variance in l decreased with sensitivity. Similarly, within species, less temporal variation was found in traits with high elasticities than in traits with less contribution to l. In some species, covariance among matrix elements also influenced the contribution of a demographic trait to l. Monitoring schemes of bird demography should be designed in such a way that temporal variances and covariances among demographic traits can be estimated. Further- more, it is important in such schemes to include data from a combination of traits that either have large sensitivities or high temporal variation.

Avian life history variation and contribution of demographic traits to the population growth rate

Determining whether seed production is pollen limited has been an area of intensive empirical study over the last two decades. Yet current evidence does not allow satisfactory assessment of the causes or consequences of pollen limitation. Here, we critically evaluate existing theory and issues concerning pollen limitation. Our main conclusion is that a change in approach is needed to determine whether pollen limitation reflects random fluctuations around a pollen–resource equilibrium, an adaptation to stochastic pollination environments, or a chronic syndrome caused by an environmental perturbation. We formalize and extend D. Haig and M. Westoby's conceptual model, and illustrate its use in guiding research on the evolutionary consequences of pollen limitation, i.e., whether plants evolve or have evolved to ameliorate pollen limitation. This synthesis also reveals that we are only beginning to understand when and how pollen limitation at the plant level translates into effects on plant population dynamics...

Pollen limitation of plant reproduction: Ecological and evolutionary causes and consequences

Stage projection (Lefkovitch) matrices for 21 species of woody plants and 45 herbaceous perennials were extracted from the plant demographic literature or compiled from published data. Each matrix was divided into six regions representing: recruitment of seeds to the seed pool; recruitment of seedlings or juveniles from current seed production; clonal growth; retrogression, due to plants decreasing in size or reverting in stage; stasis, (survival from one year to the next in the same stage class); progression to later stage classes. Matrix analysis was used to calculate the finite rate of increase λ for each population and to calculate the elasticities of each transition coefficient in the matrices (...)

comparative plant demography - relative importance of life-cycle components to the finite rate of increase in woody and herbaceous perennials

(1) The effects of three levels of defoliation at four stages of development on leaf production, reproduction probability, fruit production and survival of an understorey palm, Astrocaryum mexicanum, were studied from 1978 to 1981. (2) Three portions of the crown were factorized with the partial defoliation treatments. (3) Completely defoliated juvenile and immature palms produced significantly fewer leaves than control plants. In mature palms, the removal of the oldest portions of the crown increased leaf production by 30%. (4) Complete defoliation and the removal of two-thirds of the oldest leaves had the effect of reducing leaf abscission in all stages, except for seedlings. (5) Defoliation had a significant effect on reproduction during all years, except 1978. Completely defoliated palms had a lower probability of reproduction and produced no fruits for three years. The removal of a small proportion of the oldest tissue significantly increased fruit production. Defoliations greater than 33% of the total number of leaves reduced the reproductive capacity of palms, except when the oldest tissue was removed. (6) The survival of totally defoliated juvenile and immature individuals was 50% less than that of undefoliated plants. The survival of mature individuals was not significanly affected by the defoliation.

https://www.jstor.org/stable/pdfplus/2260433.pdf

Effects of experimental defoliation on growth, reproduction and survival of Astrocaryum mexicanum.

Seeds are a very imporatnt component of the life cycle of plants. They are not only carry the necessary genetic variation required for evolutionary change, but they are quite often the only means of l

Seed Biology of Palms: A Review

Patterns of sexual reproduction and clonal growth were investigated in the understory palm Reinhardtia gracilis var. gracilior over a 3-yr period. R. gracilis is a very abundant clonal palm in the tropical rain forest of Los Tuxtlas, Veracruz, Mexico. Because ramets form clumps, genets are easily identified in the field. Genets were monitored in a 0.5-ha area, and classified by size according to the number of ramets they possessed. In contrast to clonal growth, sexual reproduction was highly dependent on genet size. The probability of reproduction, the number of inflorescences, and the number of fruits produced were positively correlated with genet size. However, neither the probability of producing a ramet, nor the number of ramets produced per genet were correlated with genet size. Over the 3 yr of study, 55% of the genet population had at least one ramet with reproductive structures, while ,1% (a single genet in one year) had six ramets with flowers. Thirty- two percent of the mature genets reproduced during each of three consecutive years. In contrast, 58% of the genets produced no new ramets during these 3 yr. No evidence was found of a trade-off between clonal growth and sexual reproduction. Ramet production increases genet size and this in turn increases genet reproductive performance. Clonal growth in this species may be viewed as a growth strategy that tends to maximize genet fitness.

https://bsapubs.onlinelibrary.wiley.com/doi/pdf/10.2307/2446436

Sexual reproduction and clonal growth in Reinhardtia gracilis (Palmae), an understory tropical palm.

http://web.ecologia.unam.mx/laboratorios/fmolina/images/stories/publicaciones/ArticulosJournals/Clark-Tapia-etal-2005-b.pdf

How important is clonal recruitment for population maintenance in rare plant species?: The case of the narrow endemic cactus, Stenocereus eruca, in Baja California, Mexico

Ana Mendoza

Papers

comparative plant demography - relative importance of life-cycle components to the finite rate of increase in woody and herbaceous perennials

Effects of experimental defoliation on growth, reproduction and survival of Astrocaryum mexicanum.

Seed Biology of Palms: A Review

Sexual reproduction and clonal growth in Reinhardtia gracilis (Palmae), an understory tropical palm.

How important is clonal recruitment for population maintenance in rare plant species?: The case of the narrow endemic cactus, Stenocereus eruca, in Baja California, Mexico