Palm Syagrus Romanzoffiana Research Articles

Early genetic consequences of defaunation in a large-seeded vertebrate-dispersed palm (Syagrus romanzoffiana).

Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the disturbed area. In addition, the percentage of dispersed recruits around conspecific adults was lower, although not significantly, in the disturbed area (median values: 0.0 vs 14.4%). On the other hand, no evidence of increased inbreeding or reduced pollen-mediated gene flow (selfing rate and diversity of pollen donors) was found in the disturbed area. Our findings are strongly suggestive of some early genetic consequences resulting from the limitation in contemporary gene flow via seeds, but not pollen, in defaunated areas. Plant-disperser mutualisms involving medium-large frugivores, which are seriously threatened in tropical systems, should therefore be protected to warrant the maintenance of seed-mediated gene flow and genetic diversity in large-seeded plants.

Lectotipificación de los nombres descritos por J. Barbosa Rodrigues en la obra “Palmae novae Paraguayenses”

Abstract Stauffer, F., L. Ramella, E. Ferreira & L. Noblick (2016). Lectotypification of names proposed by J. Barbosa Rodrigues in the publication “Palmae novae Paraguayenses”. Candollea 71: 105–115. In Spanish, English and Spanish abstracts. DOI: http://dx.doi.org/10.15553/c2016v711a13 In the frame of the treatment of the family Palmae to be published in the Flora del Paraguay, lectotypes are designated for the following names described by J. Barbosa Rodrigues in the publication “Palmae novae Paraguayenses”: Attalea guaranitica Barb. Rodr., Bactris anisitsii Barb. Rodr., Cocos paraguayensis Barb. Rodr. and Cocos sapida Barb. Rodr. The latter is here proposed as a new synonym of the widely distributed South-eastern Brazil - Southern Cone palm Syagrus romanzoffiana (Cham.) Glassman. The fate of the important palm collection gathered by Barbosa Rodrigues is here discussed and notes on the palms described in the publication are added in order to better define their taxonomic identity.

Reproductive phenology, seed removal and early regeneration in relation to distance from parental plants of a native palm in small Atlantic forest fragments

The Brazilian Atlantic Forest is a global biodiversity hotspot, but most of what remains are small fragments. Small fragments are often harsh environments for forest plant recruitment due to edge effects and the loss of frugivorous animals that provide seed dispersal. We recorded the one-year reproductive phenology of the keystone palm Syagrus romanzoffiana in small (<2.5ha) Atlantic Forest fragments in southeastern Brazil. We tested the Janzen-Connell hypothesis with seed-removal experiments and followed the five-year survival of recruits in relation to the distance from parental plants. Palms produced many fruits throughout the year (mean 2,600/plant). More seedlings were found away from parental plants than near them, thereby supporting the Janzen-Connell hypothesis. Almost 45% of seedlings alive in 2010 were dead five years later, but recruitment of new seedlings compensated for this mortality. Distance-dependent factors influenced the density of early ontogenetic stages, but had limited effects on juveniles or on seed removal. High seed production, seed dispersal provided by disturbance-tolerant frugivores and the relatively long-term survival of adults, seedlings and juveniles seem to allow the persistence of S. romanzoffiana in the forest fragments, but possibly at the cost of an increased clumped distribution and reduced gene flow at the landscape scale.

Patch size, shape and edge distance influence seed predation on a palm species in the Atlantic forest

Seed predation is an important ecological process that affects the abundance, diversity and distribution of plant species, and it is known to be influenced by defaunation and forest fragmentation. Most studies on seed predation in human‐modified landscapes do not take into account the different spatial scales in which this process operates. In this study, we evaluated how variables at three distinct spatial scales affected the seed predation of a palm that provides a keystone resource to the frugivore community, the queen palmSyagrus romanzoffiana. Thirteen landscapes that vary in forest cover, number of fragments and patch sizes were sampled in the Brazilian Atlantic forest. We also evaluated the contribution of the three main groups of seed predators: squirrels, terrestrial rodents and invertebrates. Our results indicate that seed predation is more affected by fragment and local variables than by landscape influences. In addition, the size of the fragment, its shape and the distance from the nearest forest edge were the main predictors of the proportion of predated seeds. Moreover, the two main seed predators (squirrels and invertebrates) responded to the same fragment and local variables. Because most of the Atlantic forest consists of small fragments, we expect that the seed predation of this keystone palm should be high in most of its distribution, with potential consequences for the frugivore community.

Temporal Variation in Seed Predation by Insects in a Population of Syagrus romanzoffiana (Arecaceae) in Santa Catarina Island, SC, Brazil

Insect seed predation may vary depending on seed production. The present study considers the hypothesis that the rates of seed predation tend to be smaller in years of higher fruit production. Thus, we monitored the production of fruits and predation of seeds of the palm Syagrus romanzoffiana over 2years in the Atlantic Forest (Parque Municipal da Lagoa do Peri, Florianópolis, SC, Brazil), between July 2006 and June 2008. Plots of 0.25m(2) were fitted under 20 mother plants and fruits were monthly collected for assessment of abundance and seed predation. There was variation in fruit production between the 2years and among reproductive plants. Predation rates were high and occurred in the predispersal phase by the Curculionidae Revena rubiginosa Boheman, Anchylorhynchus aegrotus Fahraeus, and Anchylorhynchus variabilis Gyllenhal. Seed predation by these species of Anchylorhynchus is first registered in the present study. In average, about 60% of the seeds monthly produced in the population tend to escape insect predation in year of high or low production, becoming available for recruitment. The predation rate was not related to the amount of fruits produced per reproductive plant. Also, different than expected, there was a positive relation between the rates of seed predation and the total of fruits produced monthly on the plots. Thus, no evidence for the satiation of insect seed predators was found in this study with S. romanzoffiana.

Seed dispersal and predation in the palm Syagrus romanzoffiana on two islands with different faunal richness, southern Brazil

Palms are considered key species in tropical forests and represent a source of food for the community of frugivores in times of scarcity. Palms have also been used as a model to investigate how the processes of dispersal and seed predation are affected by fragmentation and alteration of tropical forests. This study examines the dispersal and seed predation of Syagrus romanzoffiana in two insular environments of different sizes (1500 ha and 50 ha) and faunal compositions, both located in the Brazilian Atlantic rainforest in Santa Catarina State, Brazil. We recorded 13 species of animals considered consumers and dispersers of fruits and seeds of S. romanzoffiana at the larger study area (Peri Lagoon Municipal Park, Santa Catarina Island) and five species on Campeche Island. In these areas, the rates of dispersal were high (Peri 57.5% to 75.5% and Campeche 81.5% to 93.0%, based on the removal experiments). In the smaller area, despite the low faunal richness, the coatis (Nasua nasua), introduced in the island were important seed dispersers. Only in Peri occurred predation by rodents (rates of 4%) due to the presence of agoutis (Dasyprocta azarae) and there was no post-dispersal predation by insects. The greatest loss of seeds (52% in both locations, based on sampling of seeds accumulated under parent plants) were caused by predation of Revena rubiginosa (Coleoptera, Curculionidae), of which oviposition occurs in the pre-dispersal phase. Besides this factor, about 40% of the seeds showed up without endosperm. However, high seed production seems to compensate for these losses, with significant seedling stock of S. romanzoffiana in both areas. Palmeiras são consideradas espécies-chave em florestas tropicais representando fonte de alimento para a comunidade de frugívoros em épocas de escassez. Palmeiras também têm sido usadas como modelo de estudo na avaliação de como os processos de dispersão e predação de sementes são afetados pela fragmentação e alteração das florestas tropicais. Este estudo examina a dispersão e predação das sementes de Syagrus romanzoffiana em dois ambientes insulares de diferentes tamanhos (1500ha e 50ha) e composições faunísticas, ambos localizados em área de Mata Atlântica no Estado de Santa Catarina, Brasil. Foram registradas 13 espécies de animais considerados consumidores e dispersores dos frutos e sementes de S. romanzoffiana na maior área estudada (Parque Municipal da Lagoa do Peri, Ilha de Santa Catarina) e cinco espécies na Ilha do Campeche. Nestas áreas, as taxas de dispersão foram altas (Peri 57,5% a 75,5% e Campeche 81,5% a 93,0%, com base em experimentos de remoção). Na menor área, apesar da baixa riqueza faunística, os quatis (Nasua nasua), introduzidos nessa ilha, foram importantes dispersores das sementes. Somente ocorreu predação por roedores no Peri (taxas de 4%) devido à presença de cotias (Dasyprocta azarae) e não houve predação pós-dispersão causada por insetos. A maior perda de sementes (52% em ambas as localidades, com base em amostragem de sementes acumuladas sob plantas-mãe) foi causada por predação de larvas de Revena rubiginosa (Coleoptera, Curculionidae), cuja oviposição ocorre na fase de pré-dispersão. Além deste fator, cerca de 40% das sementes mostravam-se sem endosperma. Contudo, a alta produção de sementes parece compensar essas perdas, havendo expressivo estoque de plântulas de S. romanzoffiana em ambas as áreas.

Fruit manipulation of the palm Syagrus romanzoffiana by vertebrates in southern Brazil

EnglishA year-long study was carried out in a deciduous forest to examine the vertebrate manipulation on fruits of Syagrus romanzoffiana in southern Brazil. Eleven 50x50 cm-track traps (each one baited with ten ripe fruits) were placed monthly around 11 adult palm trees, totalling a sampling effort of 935 traps. The fruits removed (absent) or chewed (left in situ) by a given vertebrate species were counted for each trap. Three species of mammals and one bird were monitored. The coati (Nasua nasua) removed more fruits (N = 250; 50 %) than chewed (N = 130; 26 %), leaving intact 120 fruits (24 %). The dusky-legged guan (Penelope obscura) also removed more fruits (N = 107; 43 %) than chewed (N = 44; 18 %), leaving intact 96 (39 %). On the other hand, the opossum (Didelphis albiventris) removed 127 (13 %), but chewed 622 (63 %), leaving intact 236 (24 %). Similarly, the agouti (Dasyprocta azarae) removed 16 (12 %), and chewed 64 (49 %), leaving intact 51 fruits (39 %). Results are discussed in light of the roles of these vertebrate species in seed dispersal of S. romanzoffiana. portuguesEste estudo teve a duracao de um ano e avaliou a manipulacao por vertebrados (tres especies de mamiferos e uma de ave) nos frutos da palmeira Syagrus romanzoffiana no sul do Brasil. Onze armadilhas de pegada de 50x50 cm (cada uma iscada com 10 frutos maduros) foram colocadas proximas a onze palmeiras adultas, totalizando um esforco amostral de 935 armadilhas. Os frutos removidos (ausentes) ou mastigados (deixados in situ) pelas especies de vertebrados foram contabilizadas para cada armadilha. Tres especies de mamiferos e uma de ave foram monitoradas. O coati (Nasua nasua) removeu 250 frutos (50%), mastigou 130 (26%) e deixou intactos 120 frutos (24%). O jacu (Penelope obscura) tambem removeu mais frutos (N = 107; 43%) do que mastigou (N = 44; 18%), deixando intactos 96 frutos (39%). O gamba (Didelphis albiventris) removeu 127 (13%), e mastigou 622 (63%), deixando intactos 236 (24%). Similarmente, a cutia (Dasyprota azarae) removeu 16 (12%), mastigou 64 (49%), deixando intactos 51 frutos (39%). Os resultados sao discutidos relacionando o papel das especies de vertebrados na dispersao de sementes de S. romanzoffiana.

Fruit manipulation of the palm Syagrus romanzoffi ana by vertebrates in southern Brazil

A year-long study was carried out in a deciduous forest to examine the vertebrate manipulation on fruits of Syagrus romanzoffiana in southern Brazil. Eleven 50x50 cm-track traps (each one baited with ten ripe fruits) were placed monthly around 11 adult palm trees, totalling a sampling effort of 935 traps. The fruits removed (absent) or chewed (left in situ) by a given vertebrate species were counted for each trap. Three species of mammals and one bird were monitored. The coati (Nasua nasua) removed more fruits (N = 250; 50 %) than chewed (N = 130; 26 %), leaving intact 120 fruits (24 %). The dusky-legged guan (Penelope obscura) also removed more fruits (N = 107; 43 %) than chewed (N = 44; 18 %), leaving intact 96 (39 %). On the other hand, the opossum (Didelphis albiventris) removed 127 (13 %), but chewed 622 (63 %), leaving intact 236 (24 %). Similarly, the agouti (Dasyprocta azarae) removed 16 (12 %), and chewed 64 (49 %), leaving intact 51 fruits (39 %). Results are discussed in light of the roles of these vertebrate species in seed dispersal of S. romanzoffiana. Key words: Atlantic forest, Dasyprocta azarae, Didelphis albiventris, Nasua nasua, palm tree, Penelope obscura, seed dispersal, fruit removal.

Seed Dispersal of the Palm Syagrus romanzoffiana by Tapirs in the Semi‐deciduous Atlantic Forest of Argentina

ABSTRACTVertebrates play a fundamental role in the dispersal of Neotropical trees, generating different seed shadows according to their physical and behavioral features. Tapirs are capable of consuming great quantities of large fruits, and they defecate seeds far from parent trees. For instance, intact seeds of the palm Syagrus romanzoffiana have been found in tapir dung piles in the Atlantic Forest of southeastern Brazil, suggesting that tapirs effectively disperse this species. However, recruitment was not examined therein. We studied tapir endozoochory of large and medium seeds in the semi‐deciduous Atlantic Forest of Argentina by examining dung piles found within Iguazu National Park. We recorded dung‐pile positions to evaluate the spatial distribution. We also counted the number of juveniles in 2 × 2 m quadrats placed on old dung piles in latrines, beneath adults and in random sites to estimate recruitment levels. Syagrus romanzoffiana seeds were present in 98 percent of dung piles, averaging &gt;200 seeds/dung pile, indicating that this species constitutes the main fruit component in the tapir's diet. Dung piles showed a clumped deposition pattern reflecting the use of latrines. Juvenile recruitment in latrines was 21 times higher than that of under‐adult sites and 500 times greater than in random sites, and correlated with the frequency of use of the areas. We concluded that the lowland tapir is a major disperser of S. romanzoffiana. Given that this palm can be considered a keystone species, a disruption of this interaction might affect the entire community of frugivores in the long term.

The parakeet Brotogeris tirica feeds on and disperses the fruits of the palm Syagrus romanzoffiana in Southeastern Brazil

Small psittacids remain unrecorded as dispersal agents of palm fruits in Brazil. I record here the plain parakeet (Brotogeris tirica), an Atlantic forest endemic, feeding on and dispersing the fruits of the palm Syagrus romanzoffiana at Ubatuba, northern coast of São Paulo, Southeastern Brazil. The birds removed the fruit and carried it away from the mother-tree in about 40% of the feeding records. While perched on trees and shrubs of the understorey, the parakeets removed and ingested most of the mesocarp, dropping the partly consumed fruit. As the parakeets damaged no the embryo and may feed at a distance from the mother-tree, they act as primary dispersal agents. This is the first substantiated record of a small Neotropical psittacid as a stomatochorous dispersal agent of palm fruits the size of A. romanzoffiana drupes.

Forest fragment size and microhabitat effects on palm seed predation

The establishment of plant species depends crucially on where the seeds are deposited. However, since most studies have been conducted in continuous forests, not much is known about the effects of forest fragmentation on the maintenance of abiotic and biotic characteristics in microhabitats and their effects on seed survival. In this study, we evaluated the effects of forest fragmentation on the predation upon the seeds of the palm Syagrus romanzoffiana in three microhabitats (interior forest, forest edge and gaps) in eight fragments of semi-deciduous Atlantic forest ranging in size from 9.5 ha to 33,845 ha in southeastern Brazil. Specifically, we examined the influence of the microhabitat structure, fauna and fragment size on the pattern of seed predation. Fragments <100 ha showed similar abiotic and biotic characteristics to those of the forest edge, with no seed predation in these areas. Forest fragments 230–380 ha in size did not present “safe sites” for S. romanzoffiana seed survival and showed high seed predation intensity in all microhabitats evaluated. In fragments larger than 1000 ha, the seed predation was lower, with abiotic and biotic differences among gaps, interior forests and forest edges. In these fragments, the survival of S. romanzoffiana seeds was related to squirrel abundance and interior forest maintenance. Based on these results, we concluded that there are no safe sites for S. romanzoffiana seed establishment in medium- and small-sized fragments as result of the biotic and abiotic pressure, respectively. We suggest that on these forest fragments, management plans are needed for the establishment of S. romanzoffiana, such as interior forest improvement and development in small-sized sites in order to minimize the edge effects, and on medium-sized fragments, we suggest post-dispersal seed protection in order to avoid seed predation by vertebrates. Our findings also stress the importance of assessing the influence of forest fragmentation on angiosperm reproductive biology as part of the effective planning for the management of fragmented areas.