Demography and potential extractive use of the liana palm, Desmoncus orthacanthos Martius (Arecaceae), in southern Quintana Roo, Mexico

Disturbance and Resilience in Tropical American Palm Populations and Communities

“…Target material is primarily leaves (e.g. Pedersen, 1996;Svenning & Macía, 2002;Valverde et al, 2006;Martínez-Ramos et al, 2009), but also palm heart (Freckelton et al, 2003), seeds (Bernal, 1998;Holm et al, 2008), fruits (Moegenburg & Levey, 2003;Holm et al, 2008), shoots (Siebert, 2000;Escalante et al, 2004), stems (Anderson & Putz, 2002), or even sap (Wright & Duber, 2001;Galetti et al, 2006).…”

“…Overall, available data tend to detect a complex effect of harvest intensity on palm growth, varying from positive (Sabal spp., Martínez-Ballesté et al, 2008;Desmoncus orthacanthos, Siebert, 2000) to neutral (Chamaedorea elegans, Martínez-Ramos et al, 2009) and negative (Geonoma deversa, Flores & Ashton, 2000), while effects on reproductive output are found to be systematically negative (Geonoma deversa, Flores & Ashton, 2000; Chamaedorea radicalis, Endress et al, 2004a,b;Chamaedorea elegans, Martínez-Ramos et al, 2009). Effects vary according to the percentage of individuals harvested, with some precise thresholds proposed in various studies (86% of seeds of Phytelephas seemannii, Bernal, 1998; 40% of shoots of Desmoncus orthacanthos, Escalante et al, 2004;22.5% of Mauritia flexuosa females harvested in fruits every 20 years, Holm et al, 2008; 33% of leaves of Astrocaryum mexicanum harvested, Mendoza et al, 1987; 30% of leaves of Thrinax radiata harvested, Calvo-Irabién et al, 2009). Harvest effects also vary according to the life-stage harvested: harvesting juveniles of Astrocaryum mexicanum may lead to population decline more rapidly than harvesting adults (Mendoza et al, 1987).…”

Individual growth, reproduction and population dynamics of Dioon merolae (Zamiaceae) under different leaf harvest histories in Central Chiapas, Mexico

“…Harvesting plant parts does not need to be effected at a commercial scale to have a negative impact on individual performance or on population viability; excessive clandestine harvest for ceremonial or commercial purposes often leads to deterioration of plant populations (Padoch, 1992;Young and Clarke, 2000;Endress et al, 2004). Experimental or observational studies indicate possible consequences on birth and death rates of plant populations due to negative effects on individual survival, reproduction and growth rates after over-harvesting of leaves (Mendoza et al, 1987;Oyama and Mendoza, 1990;Chazdon, 1991;Vanderklein and Reich, 1999;Ticktin et al, 2002;Anten et al, 2003), stems and fruits (Escalante et al, 2004;Holm et al, 2008), or entire individuals (Pinard, 1993;Olmsted and Álvarez-Buylla, 1995;Freckleton et al, 2003;Raimondo and Donaldson, 2003). Yet some studies have shown no effects (Endress et al, 2006) or positive effects on population growth when defoliation is not severe (López-Toledo, 2003).…”

Demography of palm species in Brazil’s Atlantic forest: a comparison of harvested and unharvested species using matrix models

“…Matrix-based demographic models also provide an excellent means by which to assess the consequences of altered recruitment for plant population dynamics (Bruna 2003), and the analysis of these matrices provides a range of measures of population structure and behavior that afford comparison between species (Caswell 2001). Finally, matrix models constitute an excellent tool for elaborating management plans in a context of sustainability (Silvertown et al 1996;Escalante et al 2004;Zuidema et al 2007). They are commonly used to project what the asymptotic growth rate of a population, or k (Caswell 2001), which can also be used as a measure of fitness for organisms possessing a particular set of traits in a particular environment (Caswell 2001).…”