We investigated the thermal thresholds to seed germination and the variations in abscisic acid (ABA) levels and oxidative metabolism during seed dormancy-breaking and germination in two palm species with differences in desiccation tolerance. We used Mauritia flexuosa (buriti palm, desiccation-sensitive seeds) from swampy habitats (Veredas) and Attalea speciosa (babassu, desiccation-tolerant seeds) from the transition zone between the forest and semi-arid region (drained soils). Germination was evaluated at 15–40°C after dormancy-breaking (operculum removal). At optimal temperature for both species (30°C), embryos were sampled in distinct germination phases – dry, imbibed, after operculum removal and at early germination – and used for quantifying ABA and hydrogen peroxide (H2O2) content, antioxidant enzyme activities and for histolocalization of superoxide anion (O2−). Seeds of M. flexuosa germinated only in a narrow temperature range (25–35°C), while A. speciosa seeds germinated between 15 and 40°C. After operculum removal, reduced ABA levels in embryos of M. flexuosa were accompanied by constant H2O2 levels, while in A. speciosa, similar levels of ABA and H2O2 were maintained throughout all germination phases. The presence of O2− was restricted to the haustorium, and an increase in O2− accumulation was observed in both species after operculum removal. Similarities were noted between both species regarding enzyme activities; however, the activities were higher in embryos from M. flexuosa. The presence of O2− only in the haustorium indicates that this region of the embryo is an active structure following imbibition and is involved in germination itself, not just functioning in reserve mobilization.

Functional traits play a key role in driving plant community effects on ecosystem function. We examined nine functional traits in various palm (Arecaceae) species and their relationships with moisture, tree-fall gaps, slope, and forest type at 29 transects (500×5 m) in the northeastern region of the Colombian Amazon. Redundancy analysis of mean trait values of species within a plot weighted by their abundance and Pearson correlations were used to evaluate the relationships between traits and environmental factors. The community trait composition was correlated with local environmental factors, which explained 23% of the trait variance. We detected functional dominance of the tallest palms in soils with high moisture and in floodplain forests (p ≤0.05). Palms with relatively long leaves were dominant in the flooded forests. Acaulescent and small palms were dominant on high slopes, and in terra firme forests, long-petioled palms were dominant in forest gaps. The number of seeds per fruit was not correlated with any environmental variable. Thus, hydrology is one of the main drivers of the functional composition of neotropical palm communities at the local scale, segregating tall palms with competitive and evasive strategies from small understory palms, which are mainly stress tolerant.

With 30 threatened species (14 categorized as Critically Endangered and 16 as Endangered, sensu IUCN), Coccothrinax (c. 54 species) is the flagship palm genus for conservation in the Caribbean Island Biodiversity Hotspot. Coccothrinax has its centre of taxonomic diversity in these islands, with c. 51 endemic species. We present a conservation framework for the 14 Critically Endangered species, found in Cuba, Haiti or the Dominican Republic. Only two species (C. jimenezii, C. montana) occur in more than one country (Haiti and the Dominican Republic). Immediate threats include oil drilling and nickel mining, intrusion of saline water into soil, urban and agricultural development, low population recruitment, uncontrolled fires, interspecific hybridization, and unsustainable ethnobotanical practices. Coccothrinax bermudezii, C. borhidiana, C. crinita ssp. crinita, C. leonis and C. spissa are not conserved in protected areas. Coccothrinax bermudezii, C. jimenezii, C. leonis and C. nipensis are not part of ex situ collections. Based on results from a conservation project targeting C. jimenezii, we recommend international cooperation between the three range states to implement integrative conservation management plans, plant exploration initiatives, taxonomic revisions, outreach, and fundraising. The ultimate aim of this review is to provide baseline information that will develop conservation synergy among relevant parties working on Coccothrinax conservation in Cuba, Haiti and the Dominican Republic. Such collaborations could also benefit through partnerships with botanists working in other countries.

Scatter-hoarding by rodents is expected to benefit palm recruitment by allowing cached seeds to escape predation and to colonize new areas, but evidence that seedlings emerge from cached seeds is scarce. We aimed to assess to what extent seedling establishment of two palm species (Astrocaryum aculeatissimum and Attalea humilis) is favoured by seed caching by rodents in a large Atlantic Forest remnant. We mapped the location of conspecific seedlings within circular plots of 15-m radius around five adult individuals of each palm species, checking if seedlings established from dispersed (>2 m from parent palms) or non-dispersed seeds (0–2 m from parent palms), and from buried or unburied seeds. We found a total of 42 A. aculeatissimum seedlings and 16 A. humilis seedlings. Nearly all (98%) seedlings established from seeds dispersed away from parents (mainly located 10–15 m from parents), and 83% and 75% of seedlings of A. aculeatissimum and A. humilis, respectively, established from seeds buried in the soil. Results show that both palm species depend almost entirely on caching of seeds by rodents to establish seedlings. Our study suggests that checking for endocarps associated with established seedlings can accurately estimate the process behind seedling establishment, improving our understanding about the net outcome of seed caching for large-seeded palms.

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), native to tropical Asian regions, has become a serious threat to palm trees all over the world. Knowledge of its flight potential is vital to improving the preventive and curative measures currently used to manage this pest. As R. ferrugineus is a quarantine pest, it is difficult to study its flight potential in the field. A computer-monitored flight mill was adapted to analyse the flying ability of R. ferrugineus through the study of different flight parameters (number of flights, total distance flown, longest single flight, flight duration, and average and maximum speed) and the influence of the weevil's sex, age, and body size on these flight parameters. Despite significant differences in the adult body size (body weight and length) of males and females, the sex of R. ferrugineus adults did not have an influence on their flight potential. Neither adult body size nor age was found to affect the weevil's flying abilities, although there was a significantly higher percentage of individuals flying that were 8–23 days old than 1–7 days old. Compared to the longest single flight, 54% of the insects were classified as short-distance flyers (covering <100 m) and 36 and 10% were classified as medium- (100–5000 m) and long-distance (>5000 m), respectively. The results are compared with similar studies on different insect species under laboratory and field conditions.

Introduction. Plants develop mechanisms that allow them to compartmentalize injuries that they suffer during their life. In trees, pruning and injection treatments must be used in accordance with precise rules to reduce risks resulting from the injuries created. Sealing in palms. Palms, contrary to widespread belief, are quite capable of “healing” injuries (sealing); because of an anatomy quite different from trees, the sealing process in palms is much simpler. Compartmentalization of injection wounds. The controversy on the use of injection in trees is due essentially to initial mistakes that have then been rectified. Injection in palms against the red palm weevil. For palms, for decades, this technique has been employed without problems and with great efficiency against various pests, including Rhynchophorus ferrugineus, the red palm weevil (RPW). Its use has been reserved for exceptional situations either to face abnormal pest proliferation, uncontrollable by other techniques, or to implement eradication programs. Integrated eradication program. In such a program, the main aim of injection treatments is preventive. With long-persistence insecticides, the number of treatments could be greatly reduced. The resulting savings in time and money would enable the organization of the treatments of all the palms located in an infested area, and consequently the rapid eradication of the pest. New perspectives. We established that insecticides applied by injection were capable of protecting palms with only two or even one treatment per year. These results suggest a radical improvement in programs to eradicate RPW, while considerably reducing the risks to health and the environment compared with spray treatments.

Palm diaspores are reported to have various kinds of dormancy. However, (1) the embryo is underdeveloped; (2) the endocarp is water permeable; and (3) the diaspores take a long time to germinate. Thus, we conclude that the diaspores of the majority of palm species have morphophysiological dormancy (MPD). The ones that do not have MPD are morphologically dormant.

Although the dioecious palm, Mauritia flexuosa plays a pivotal role in Amazonian ecology and economy, little is known about its flowering and fruiting patterns. We investigated the role of habitat and inter-annual precipitation in the phenology of M. flexuosa. We calculated sex ratios and recorded phenology for 20 mo in four populations (N = 246) of savanna–forest ecotone (two sites) and forest (two sites) habitat in Roraima, Brazilian Amazonia. Sex ratios were significantly female-biased, and >98% of females set fruit. No significant relationship was found between habitat and sex. Flowering occurred at the wet/dry season interface (August–November), and fruit maturation occurred during the wet season (May–August). Males and females flowered synchronously, and neither the onset nor termination of flowering differed significantly between habitats. Flowering was negatively associated with present precipitation and positively correlated with prior precipitation (3 mo). Fruiting was positively associated with present precipitation and unrelated to prior precipitation (3 mo). We conclude that habitat has an insignificant effect, although short-term climatic variation may influence phenology of this species in northern Amazonia. These results highlight the need for long-term studies relating flowering and fruiting events, and inter-annual climatic variation.

Disjunctions between Africa and the Neotropics present a puzzle that is key to understanding the biogeography of the diverse floras and faunas of both continents. Many authors have proposed that Raphia taedigera Maur., the sole Neotropical representative of an otherwise African genus, has been introduced to the New World. Paleoecological data from a freshwater swamp in Nicaragua, which yielded R. taedigera pollen dating to 2800 ± 90 y before present (BP) and Raphia seed fragments from 2040 ± 60 BP are presented. These illustrate that Raphia taedigera arrived in the New World before trans-Atlantic trade by humans and thus arrived as a result of a natural phenomenon. The lack of differentiation of R. taedigera from the African sister taxon, R. vinifera, suggests recent separation of the two species (i.e. after the creation of the southern Atlantic Ocean by the splitting of West Gondwana). Other evidence supports dispersal of Raphia by ocean currents. The palm probably arrived from Africa by floating as an individual fruit or on a raft of vegetation. Thus, R. taedigera represents another example of trans-Atlantic dispersal, strengthening the link between the flora and fauna of Africa and the Neotropics.

Seed predation by native and alien rodents can limit plant recruitment and ultimately affect forest dynamics and composition (Campbell & Atkinson 2002, Côté et al. 2003, Hulme 1998, Sánchez-Cordero & Martínez-Gallardo 1998). Even partial consumption of seeds by predators may affect plant community structure, though its importance is poorly understood (Steele et al. 1993, Vallejo-Marín et al. 2006). Despite consumption of relatively large portions of seeds by herbivores, seeds can retain their ability to germinate if the embryo remains intact (Dalling & Harms 1999, Janzen 1972, Mack 1998). Germination of damaged seeds may be accelerated or prolonged (Karban & Lowenberg 1992, Koptur 1998, Vallejo-Marín et al. 2006). Damage by seed pests also facilitates ageing stress; which manifests as decreased seedling vigour, decreased seed viability, lower germination percentages and slower germination rates (Priestley 1986).

The conservation status of 134 species, subspecies and varieties of West Indian palms (Arecaceae) is assessed and reviewed, based on field studies and current literature. We find that 90% of the palm taxa of the West Indies are endemic. Using the IUCN Red List categories one species is categorized as Extinct, 11 taxa as Critically Endangered, 19 as Endangered, and 21 as Vulnerable. Fifty-seven taxa are classified as Least Concern. Twenty-five taxa are Data Deficient, an indication that additional field studies are urgently needed. The 11 Critically Endangered taxa warrant immediate conservation action; some are currently the subject of ex situ and in situ conservation projects in the region’s botanical gardens. We recommend that preliminary conservation assessments be made of the 25 Data Deficient taxa so that conservation measures can be implemented for those facing imminent threats.

Frugivorous and granivorous vertebrates often discriminate against seeds and fruits infested by insects (Sallabanks & Courtney 1992). Insects may actively render seed or fruit unpalatable or unusable to vertebrates as a strategy to maximize the amount of food available to themselves (Janzen 1977). Nevertheless, vertebrates sometimes do not differentiate between sound and infested seeds or fruits (Dixon et al. 1997, Weckerly et al. 1989), or even prefer insect-infested seeds and fruits to sound ones (Sallabanks & Courtney 1992, Semel & Andersen 1988, Steele et al. 1996, Valburg 1992). Possible reasons for vertebrates to prefer infested seeds include: (1) seeds with larvae having a higher nutritional value than sound ones, because larvae synthesize fat and/or proteins (Sallabanks & Courtney 1992, Valburg 1992) or other nutrients such as vitamins (Havera & Smith 1979, Semel & Andersen 1988, Steele et al. 1996); (2) seeds with larvae tasting better than sound seeds (Borowicz 1988); and (3) seeds with larvae may be more easily opened and consumed than sound seeds (Borowicz 1988).

Despite the importance of the palm family, Arecaceae, little has been systematically documented about the seed behaviour of the many species. The post-harvest seed behaviour of Phoenix reclinata, the highly utilized wild date palm species distributed along the eastern seaboard of Africa, is investigated in the present study. While both embryo and endosperm water concentration declined as the seeds of Phoenix reclinata matured, they remained relatively high: this is a characteristic of (but not confined to) non-orthodox seeds. The ultrastructure of embryo cells, and the finding that negligible water uptake was required for the initiation of germination, were in keeping with the possible non-orthodox nature of the seeds. A developmental study revealed that between the acquisition of full germinability and complete pre-shedding maturity, germination performance appeared to be constrained, suggesting the presence of an inhibitor. Pre-treatment by soaking, mechanical or acid scarification had no significant promotory effect on either rate or totality of germination of mature P. reclinata seeds, while use of water transiently at 100°C was highly deleterious. However, germination of partially dehydrated seeds was initiated sooner if they had been soaked or scarified. Mature P. reclinata seeds tolerated dehydration to a mean embryo water concentration of 0.40 g g–1 (dry mass basis; dmb), but at 0.14 g g–1, both rate and totality of germination were adversely affected. However, viability of seeds dehydrated to the mean embryo water concentration 0.40 g g–1 declined during storage for 16 weeks. It is concluded that P. reclinata seeds are non-orthodox, and are best categorized as showing intermediate post-harvest behaviour.

Over recent decades, studies on post-dispersal seed predation have revealed some general patterns despite dealing with a highly variable phenomenon (reviews in Crawley 1993, Hulme 1998). Most of these studies, however, were carried out with plant species whose population density range from low to moderately high (Hulme 1998). Only rarely has seed predation been studied in very dense stands of a given plant species (Schupp 1988a, b, 1992). In such a situation, seed predators might respond to the local availability of seeds in a manner that differs from their response under conditions of low seed density. For instance, a high density of seeds beneath a fruiting plant may attract seed predators, causing a positive correlation between predation and seed density (Janzen 1970). Schupp (1992), however, noted that at a population scale, a high density of seeds could satiate predators, resulting in a negative correlation between predation and seed density (see also Burkey 1994).

The reproductive biology of the dioecious understorey palm Chamaedorea radicalis was investigated in order to identify the primary pollen vector and quantify the relationship between female fecundity and local neighbourhood sexual composition. The study was conducted in a montane mesophyll forest within the El Cielo Biosphere Reserve, Tamaulipas, Mexico. The species is considered vulnerable in Mexico and there are concerns about the sustainability of leaf harvest. We determined that wind is the primary pollen vector, based both on floral and pollen morphological characters, and on a pollinator exclosure experiment. Successful wind pollination of this understorey palm was facilitated by the extended flowering period of males, which allows one male to be a source of pollen to receptive females for as long as a month. The number of flowers and fruits borne on a female were dependent on female size, however, no size parameter correlated well with fruit set. Fruit set was also not dependent on local sexual composition, male density or distance to the nearest male, suggesting that in this study area female reproductive success is not limited by the availability of pollen.

The conservation status of 23 Hawaiian endemic palms, Pritchardia spp., is reviewed. Field survey reports, recovery plans, herbaria holdings and observations have been utilized to assess each taxon's current range and status. Eleven species are categorized as Critically Endangered, nine Endangered, two Vulnerable and one as Data Deficient when subject to the IUCN Red List criteria. Conservation management options are discussed. A large proportion of this genus is on the verge of extinction and will continue to decline in the wild without active conservation management. Recommendations involving long-term management include maintaining and protecting the existing wild populations, establishment of effective ex situ populations, reintroduction into the wild, and the establishment of procedures to deal with invasive plants and animals.

The Amazonian rain forests form one of the largest areas of continuous forest in the world, and they harbour a substantial part of the world's biodiversity (World Conservation Monitoring Centre 1992). The extravagant species richness of Amazonia makes collecting information on species distribution patterns there a formidable challenge. Relatively few studies have been able to provide data that cover both a large enough number of species and wide enough geographical areas to allow relevant biogeographical and ecological generalizations (such studies concerning plants include Balslev 1988, de Oliveira & Daly 1999, Pitman et al. 1999, Prance 1973, ter Steege et al. 2000, Terborgh & Andresen 1998, Tuomisto & Poulsen 1996). The scarcity of field observations is undoubtedly one of the reasons why very different ideas exist about the mechanisms that control plant distributions and patterns of species richness in Amazonia (Balslev 1988, Condit 1996, Gentry 1988, Nelson et al 1990, Pitman et al. 1999, Prance 1973, 1982; ter Steege et al. 2000, Tuomisto et al. 1995).

The study presented here investigated the importance of environmental heterogeneity and clumping for the mesoscale distribution patterns of five palm species in old-growth Andean forest (Maquipucuna, Ecuador). Seedlings, juveniles and adults were recorded in 167 plots located throughout the 3-km × 3-km study area. Mountain (Cerro Sosa or Cerro Sta. Lucia), altitude, aspect, topographic-edaphic conditions and forest structure were also recorded. The following questions were investigated: (1) Are the distributions related to environmental heterogeneity? (2) Are the distribution patterns consistent with severe recruitment limitation? The distribution patterns of four species were related to environmental heterogeneity, especially to that created by the mountainous landscape itself, and at least four of the five species also exhibited strong clumping that was clearly linked to spatially restricted recruitment and could not be explained by the environmental parameters. Thus, both niche specialization and recruitment limitation probably play important roles in Andean palm community ecology. Consistent differences among the two mountains in forest structure and the frequency of certain palm stages most likely reflected extractivism.