Leaf production, reproductive patterns, field germination and seedling survival in Chamaedorea bartlingiana, a dioecious understory palm

Abstract

Chamaedorea bartlingiana is a dioecious palm that grows in the cloud forest understories of the Venezuelan Andes. Age and sexual differences in phenology and reproductive patterns were studied in labelled individuals of all age categories. This species has long-lived leaves and low leaf production, both characteristic of understory plants. Growth rates are lower in juveniles than in adults and in females than in males, as in other palms. Male and female individuals show different reproductive patterns. Male inflorescences are always produced at the same rate and the probability of surviving until anthesis is constant. Females produce reproductive buds at the same rate as males, but these buds have a 35% probability of becoming a ripe infrutescence if the plant has infrutescences already growing, and 70% if it does not. This pattern and the slow growth of inflorescences (1 year for males from bud to flowers, 2 years for females from bud to ripe fruits) cause a pluriannual reproductive pattern at the population level. Field germination does not follow this pattern, but shows one annual peak probably related to environmental conditions.

Growth and reproduction of the understory palm Geonoma schottiana Mart. in the gallery forest in Central Brazil

“…Consequently the maximum flowering rate is set by leaf production rate (Ataroff & Schwarzkopf 1992, Cunningham 1995. Leaf production in reproductive individuals of G. schottiana (4.6 leaves year -1 ) was at least 1.5 times higher then inflorescence production (2.75 infl year -1 ).…”

“…Reproductive structures can be classified into four developmental phases, similar to those adopted by Ataroff & Schwarzkopf (1992) and by Martén & Quesada (2001): (i) inflorescence without fruits -this phase begins with the emergence of an inflorescence from the interior of the bract, includes the elongation of the rachis, rachillae and floral anthesis, and finishes with the abscission of the pistillate flowers and the emergence of developing fruits; (ii) infructescence with small fruits -the phase begins when the fruits are still small and bright green and ends when they reach nearly the size of ripe fruits, but while the color is still bright green; (iii) infrutescence with green fruits -most fruits are similar in size to the ripe fruits, but are opaque green; (iv) infrutescence with ripe fruits -almost all fruits are purple and black, although some still can be green. Reproduction is complete when the most of the fruits had been dispersed and rachis and rachillae become dry and brittle.…”

“…Many factors influence leafing seasonality (review in Fenner 1998), mainly climatic variables, such as precipitation (De Steven et al 1987, Scariot et al 1991, Voeks 2002, but see Ataroff & Schwarzkopf 1992), and irradiance (Wright & Van Schaik 1994). Where water is not a limiting factor, seasonal peaks of irradiance may play a predominant role in leaf production (Wright & Van Schaik 1994).…”

Population dynamics of the rat Microryzomys minutus (Rodentia: Muridae) in the Venezuelan Andes

“…It could be a consequence of food availability throughout the year (Seres and Ramírez 1993) and the absence of a real dry season. Although food availability is greatest when palm seedlings are more abundant (Ataroff and Schwarzkopf 1992), rats can eat other items as Renealmia sp. fruits, which are available during the whole year (Seres and Ramírez 1993), and obtain energy enough to breed at any time.…”

Dinâmica Do Banco De Plântulas De Palmito Em Ambiente Natural

“…Ash (1988) [1] e Ataroff (1992) [2] baseados em dados da produção de folhas encontraram resultado semelhante ao estudarem as palmeiras Balaka microcarpa Burret e Chamaedorea bartlingiana H. Wendl., respectivamente.…”