On the ecology and evolution of annual plants in disturbed environments

Abstract

This paper is concerned with the effect of disturbance on some crucial characteristics of annual plants. The theoretically optimal life-history traits that maximize individual fitness in disturbed environments are described and critically evaluated. It seems that none of them holds for all annual species.Self-pollination and especially seed polymorphism are considered important adaptations to life in unpredictable environments. The thesis is put forward that amphicarpic annuals, which exhibit both self-pollination and extreme seed polymorphism, are best adapted to life in hazardous habitats. The hypothetical course of the evolution of amphicarpy is demonstrated on the grounds of the comparison of contemporary annual species producing chasmogamous and cleistogamous flowers on a single individual.Nomenclature: follows Flora Europaea (Tutin et al. 1964(Tutin et al. -1980, except for non-European species where the nomenclature used in the papers cited has been followed.

An integrated morpho‐molecular study of Salicornia (Amaranthaceae‐Chenopodiaceae) in Iran proves Irano‐Turanian region the major center of diversity of annual glasswort species

“…The perennials are usually sensitive to such unpredictable conditions similar to disturbed and desert habitats. Therefore, diversification of annuals on the saline inland marshes is expected as a result of ecological pressure (Symonides, 1988;Davy & al., 2001;.…”

Long-term impacts of abundant perennial water provision for game on herbaceous vegetation in a semi-arid African savanna woodland

“…(generally annuals) since 1980 can be attributed to drought and its tolerance to grazing (O'Connor, 1994). The high relative cover in 1996 of the forbs D. tomentosa and C. angustifolia is indicative of deterioration in range condition and supports Symonides' (1988) assessment of rapid and often irregular fluctuations in both species composition and dominance structure of plant communities in disturbed environments. Dicoma tomentosa is conspicuous by its absence in the comprehensive plant checklist compiled by Zambatis (1994) for Klaserie.…”

Soil climate underpins year effects driving divergent outcomes in semi-arid cropland to grassland restoration

“…Establishing targeted species or communities after restoration treatment is dependent upon climate and landscape factors and inter-specific ecological processes including the strength and timing of competition (Young et al, 2015;Germino et al, 2018). For example, introduced annuals can be well-adapted to unpredictable conditions (Symonides, 1988), and when abundant, can slow down the colonization of perennials due to competition for resources (Bakker et al, 2003), altered nutrient fluxes (Mahood et al, 2022;Yang et al, 2023) and changes to hydraulic connectivity (Turnbull et al, 2012). In arid grasslands, some native perennial species compete well against introduced annuals.…”