High tree alpha-diversity in Amazonian Ecuador

In a 1 ha square plot of terra firme forest at 260 m elevation in Amazonian Ecuador, all trees with diameter at breast height (dbh) 5 cm were studied. There were 1561 individuals, 473 species, 187 genera and 54 families. Of these, 693 individuals, 307 species, 138 genera and 46 families had a dbh 10 cm. This is the highest number of tree species ever recorded for a tropical rain forest sample of this size. In both dbh classes, the most species-rich families were: Fabaceae sensu lato (including Mimosaceae and Caesalpiniaceae), Lauraceae and Sapotaceae; the most species-rich genera, were Pouteria, Inga and Protium. The vertical space was partitioned among species: 166 species were found only in the 5–10 dbh cm class and were mostly sub-canopy treelets, and 307 species with dbh 10 cm were mostly large canopy trees.     

Multiplicity in palm uses by the Huaorani of Amazonian Ecuador

An ethnobotanical study of the palms used by the Huaorani in the Yasuní National Park and Huaorani Ethnic Reserve in Amazonian Ecuador was carried out. In this inventory, 37 palm species were found; all were used by the Huaoranis. One hundred and ninety-one different uses were recorded in eight ethnobotanical categories. Most species (64.9%) were used for house construction and human food. More than half of the species were used for domestic utensils (59.4%) and hunting and fishing implements (54%). A comparison is made between these data and past studies for the other six indigenous communities from Amazonian Ecuador. This paper shows the highest diversity of useful palm species and the highest number of different uses ever recorded for an indigenous group in Amazonian Ecuador. The data combine quantitative and qualitative approaches.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 149–159.     

Useful lianas of the Siona-Secoya Indians from Amazonian Ecuador

An ethnobotanical inventory of lianas was carried out in a 1-ha plot of tropical moist forest in the Cuyabeno Reserve, Amazonian Ecuador. We obtained information about the uses that the Siona-Secoya Indians have for lianas. Of 98 species in the 1-ha plot, 47% were useful for the Siona-Secoya. Of the species used, 67% were for medicines, food, stimulants, and poisons; 17% had ritual applications, and 15% were used to make ropes or to weave baskets, toys, and ornaments. The species of lianas that were most useful were the ones with the highest values of ecological parameters such as density, dominance, and relative length. There is a close relationship between the ecological characteristics of the liana community and the uses made of it by the Indians.     

Species Diversity and Distribution Patterns of the Ants of Amazonian Ecuador

Ants are among the most diverse, abundant and ecologically significant organisms on earth. Although their species richness appears to be greatest in the New World tropics, global patterns of ant diversity and distribution are not well understood. We comprehensively surveyed ant diversity in a lowland primary rainforest in Western Amazonia, Ecuador using canopy fogging, pitfall traps, baits, hand collecting, mini-Winkler devices and subterranean probes to sample ants. A total of 489 ant species comprising 64 genera in nine subfamilies were identified from samples collected in only 0.16 square kilometers. The most species-rich genera were Camponotus, Pheidole, Pseudomyrmex, Pachycondyla, Brachymyrmex, and Crematogaster. Camponotus and Pseudomyrmex were most diverse in the canopy, while Pheidole was most diverse on the ground. The three most abundant ground-dwelling ant genera were Pheidole, Solenopsis and Pyramica. Crematogaster carinata was the most abundant ant species in the canopy; Wasmannia auropunctata was most abundant on the ground, and the army ant Labidus coecus was the most abundant subterranean species. Ant species composition among strata was significantly different: 80% of species were found in only one stratum, 17% in two strata, and 3% in all three strata. Elevation and the number of logs and twigs available as nest sites were significant predictors of ground-dwelling ant species richness. Canopy species richness was not correlated with any ecological variable measured. Subterranean species richness was negatively correlated with depth in the soil. When ant species were categorized using a functional group matrix based on diet, nest-site preference and foraging ecology, the greatest diversity was found in Omnivorous Canopy Nesters. Our study indicates ant species richness is exceptionally high at Tiputini. We project 647–736 ant species in this global hotspot of biodiversity. Considering the relatively small area surveyed, this region of western Amazonia appears to support the most diverse ant fauna yet recorded.     

Microhabitat specialization in a species-rich palm community in Amazonian Ecuador

1 Relationships between microhabitat variables (altitude, inclination, topographic position, drainage, canopy height) and the distribution and abundance of palms and palm-like plants in 50 ha of old-growth terra firme rain forest in the Yasuní National Park, lowland Amazonian Ecuador, were examined using 118 20 × 20 m plots laid out in a stratified random design.
2 If microhabitat niche differentiation is important for maintaining the species richness of the community, then (i) the distribution of the palms will be strongly influenced by microhabitat heterogeneity and (ii) palms of similar growth form will show antagonistic microhabitat relationships.
3 Mantel and cluster analyses showed that palm species distributions were strongly structured by topography. The main difference in species composition was between plots in the bottomland and plots on the upper slopes and hill tops.
4 Logistic and logit analyses showed that 20 of the 31 palm and palm-like taxa analysed had distributions that were significantly related to the microhabitat variables measured, mainly to topography but also to drainage and canopy height.
5 Spatial autocorrelation in the overall community structure was not explained by the microhabitat variables. Analyses of distributions or abundances of single species showed neighbourhood effects for seven taxa.
6 Antagonistic patterns of microhabitat preferences were recognizable among some species pairs of small palms, medium-sized palms and palm-like plants, but not among canopy palms.
7 It is concluded that microhabitat specialization is an important factor in maintaining the diversity of this palm community, while mass effects might also be important.     

Ethnobotany of the fiber palmAstrocaryum chambira (Arecaceae) in Amazonian Ecuador

Astrocaryum chambira Burret is native to the western parts of the Amazon basin where indigenous people use it as a source of fiber. Its use among four different indigenous groups in Ecuador is described here. They extract fibers from the pinnae, mostly of the young leaves. Both men and women twist the fibers into strings in their homes after hunting and work in the fields. The main items produced are woven hammocks, bags, and nets. These products represent the main source of cash income for many indigenous people. The highest value for their products is obtained from sale directly to tourists. The commercial use ofA. chambira can possibly be increased in extractivism along with better marketing. The variety of ways this palm is used also makes it a valuable species for agroforestry.     

Growth and mortality of trees in Amazonian tropical rain forest in Ecuador

Abstract. Structural changes are analysed in four samples representing 4 ha, two line transects and two hectare plots, of Amazonian tropical lowland rain forest in northern Ecuador. Only trees with a DBH ≥ 10 cm were included. A sample of floodplain forest in Añangu represents the largest turnover found in tropical forests (stand half-life = 23 yr). The line transect and hectare plot both of tierra firme forest in Añangu have the same turnover (37 yr) and were balanced for death and in-growth of both individuals and wood (basal area). The 1-ha tierra firme sample in Cuyabeno had a turnover of 67 yr and was in a growing phase. The floodplain line transect in Añangu was in a phase of structural breakdown. However, the floodplain line transect had the largest growth of basal area per tree (23.4 cm²/yr). The tierra firme samples had a growth of 9.6, 10.1, and 13.6 cm²/yr. Most of the dead trees fell with some uprooting in three of the four samples. However, no significant difference in the distribution of mode of death was found between the four samples. Death was independent of topography and the dead trees were randomly distributed. As the trees grow up they occupy more space and larger trees (DBH ≥ 15 cm) become more uniformly distributed, whereas smaller trees (DBH ≤ 15 cm) were randomly distributed. Our study confirms that plots of 1 ha are not sufficient to include representative samples of different stages of forest structure.     

Remembering: functional organization of the declarative memory system

How do brain systems support our subjective experience of recollection and our senses of familiarity and novelty? A new functional imaging study concludes that each of these functions is accomplished by a distinct component of the medial temporal lobe, shedding new light on the functional organization of this memory system.     

Hallucinogenic plants of the Shuar and related indigenous groups in Amazonian Ecuador and Peru

Banisteriopsis caapi, Brugmansia suaveolens, andNicotiana tabacum are the principal hallucinogens used by the Shuar and related ethnic groups in Amazonian Ecuador and Peru. These three species are common hallucinogens throughout northwestern Amazonia.Banisteriopsis caapi (natem) is the hallucinogen most frequently employed by the Shuar. The Shuar drink the juice ofN. tabacum duringnatem healing ceremonies. They also believe that smoke fromN. tabacum cigarettes repel evil spirits.Brugmansia suaveolens is the strongest Shuar hallucinogen. Considered very dangerous, it sometimes is added tonatem mixtures or it may be taken alone. Other plants used in hallucinogens or in narcotic beverages includeBrunfelsia grandiflora, Cyperus spp.,Diplopterys cabrerana, Heliconia stricta, Herrania spp., andIlex guayusa.     

Distribution and abundance of tree species in swamp forests of Amazonian Ecuador

Research to date on Amazonian swamps has reinforced the impression that tree communities there are dominated by a small, morphologically specialized subset of the regional flora capable of surviving physiologically challenging conditions. In this paper, using data from a large‐scale tree inventory in upland, floodplain, and mixed palm swamp forests in Amazonian Ecuador, we report that tree communities growing on well‐drained and saturated soils are more similar than previously appreciated. While our data support the traditional view of Amazonian swamp forests as low‐diversity tree communities dominated by palms, they also reveal four patterns that have not been well documented in the literature to date: 1) tree communities in these swamp forests are dominated by a phylogenetically diverse oligarchy of 30 frequent and common species; 2) swamp specialists account for < 10% of species and a minority of stems; 3) most tree species recorded in swamps (> 80%) also occur in adjacent well‐drained forest types; and 4) many tree species present in swamps are common in well‐drained forests (e.g. upland oligarchs account for 34.1% of all swamp stems). These observations imply that, as in the temperate zone, the composition and structure of Amazonian swamp vegetation are determined by a combination of local‐scale environmental filters (e.g. plant survival in permanently saturated soils) and landscape‐scale patterns and processes (e.g. the composition and structure of tree communities in adjacent non‐swamp habitats, the dispersal of propagules from those habitats to swamps). We conclude with suggestions for further research to quantify the relative contributions of these factors in structuring tree communities in Amazonian swamps.     

Habitat niche partitioning by 16 species of Myristicaceae in Amazonian Ecuador

The distribution and spatial pattern of plants in tropical forests have important implications for how species interact with each other and their environments. In this article we use a large-scale permanent census plot to address if the coexistence of 16 co-occurring species of Myristicaceae is aided by topographic and light gradient niche partitioning. We used a second order spatial pattern analysis based on Ripley’s K function to describe species’ distributions and associations among species, and a torus translation procedure to test for associations with three topographically defined habitats. A majority of species displayed spatial aggregation and over half had one or more significant habitat associations. Four species were associated with the ridge habitat, four species with slope habitat, and two with valley habitat. Seven other species showed no habitat association. Within each habitat group, species exhibited a variety of distributions in relation to light availability. However, habitat associations were largely unexplained by differential rates of mortality, growth or recruitment over a 5-year interval. We conclude that although in principle partitioning of the topographic and light environments may double or treble the number of species able to coexist, there is no evidence that partitioning of physical habitats can explain the coexistence of all 16 of these closely related species.     

Reproductive Biology of the Monoecious Understory Palm Prestoea schultzeana in Amazonian Ecuador1

Prestoea schultzeana is a monoecious, protandrous palm in the forest understory of Amazonian Ecuador. We studied its leaf production, population density, sexual expression, phenology, pollination, and the specificity of the floral visitors. On average, 1.4 leaves and 0.9 inflorescences are produced per individual per year. The number of staminate flowers per inflorescence is relatively constant compared with the number of pistillate flowers which varies greatly. Flowering occurs in staminate and pistillate phases of approximately 19 and 0–7 days duration, respectively. Flowers open in the morning, and staminate flowers abscise in the afternoon of the same day whereas pistillate flowers last for two days. Flowers are whitish-yellow with a sweet odor and produce nectar. They were visited by Coleoptera (Chrysomelidae, Curculionidae, Nitidulidae, Ptiliidae, Staphylinidae), Hemiptera, Diptera (Drosophilidae, Syrphidae, Ceratopogonidae), Lepidoptera (Nymphalidae), and Hymenoptera (Formicidae, Halictidae). All examined individuals of the syrphid fly Copestylum sp. visiting pistillate flowers carried 100–500 grains of P. schultzeana pollen. Pollen occurred on all body parts, but especially on the legs, and this makes Copestylum sp. the most important pollinator. Most floral visitors were also frequent on the flowers of co-occurring plant species; notably the palm Hyospathe elegans shared most visitor species with P. schultzeana.     

Meteorological complexity in the Amazonian area of Ecuador: An approach based on dynamical system theory

Meteorological rhythms and trends are important components for ecosystem functioning. The complex time evolution of meteorology is often difficult to capture using linear methods. The objective of this work was to use basic concepts of dynamical system theory for assessing time evolution of daily records from six local meteorological variables collected at the Amazonian basin. We analysed rainfall, relative humidity, evaporation, minimum temperature, relative sunshine duration and evaporation/precipitation ratio. Data were collected from Puyo meteorological station, Pastaza Province, Ecuador. Data sets covered 4 years (from 1st January 2001 to 1st January 2005) (a total of 1460 data points). The TISEAN Software Package (public domain software available at http://www.mpipks-dresdren.mpg.de/～tisean) was used for deriving nonlinear parameters from each time series. We found interesting evidence of chaotic behaviour as maximal Lyapunov exponents were positive for all time series considered. These results were consistent with those computed from corresponding surrogate time series. Positive Lyapunov exponents allow an estimation of the lead time of correlation for making reliable predictions.     

High foliicolous lichen alpha-diversity on individual leaves in Costa Rica and Amazonian Ecuador

Two individual, dicotyledoneous leaves (125 and 98 cm² in size) and one composed palm leaf (c. 6800 cm² in size), gathered at La Selva Biological Station, Costa Rica, and Jatun Satcha Biological Station, Amazonian Ecuador, were screened for small-scale foliicolous lichen diversity. On the dicotyledoneous leaf from Costa Rica, 49 lichens and one lichenicolous fungus were found, while a comparable leaf from Ecuador revealed 46 lichens and two lichenicolous fungi. The palm leaf yielded 81 lichens and one lichenicolous fungus. This is the highest alpha-diversity so far reported for foliicolous lichens on individual leaves and invites for comparison with tree diversity in tropical rain forests. Due to the high proportion of species represented by a single thallus, the taxonomic diversity of lichens on individual leaves (or trees in selected plots) cannot be self-supporting, but reflects a high degree of dispersion or entropy within the community of which the individual leaf (or selected plot) is part. Diversity is therefore fractal, showing similar patterns at different scales, each part of a given community reflecting the entire community. Thus, mechanisms that result in high small-scale diversity must be looked for at the community level.     

Color vision and niche partitioning in a diverse neotropical primate community in lowland Amazonian Ecuador

A recent focus in community ecology has been on how within‐species variability shapes interspecific niche partitioning. Primate color vision offers a rich system in which to explore this issue. Most neotropical primates exhibit intraspecific variation in color vision due to allelic variation at the middle‐to‐long‐wavelength opsin gene on the X chromosome. Studies of opsin polymorphisms have typically sampled primates from different sites, limiting the ability to relate this genetic diversity to niche partitioning. We surveyed genetic variation in color vision of five primate species, belonging to all three families of the primate infraorder Platyrrhini, found in the Yasuní Biosphere Reserve in Ecuador. The frugivorous spider monkeys and woolly monkeys (Ateles belzebuth and Lagothrix lagotricha poeppigii, family Atelidae) each had two opsin alleles, and more than 75% of individuals carried the longest‐wavelength (553–556 nm) allele. Among the other species, Saimiri sciureus macrodon (family Cebidae) and Pithecia aequatorialis (family Pitheciidae) had three alleles, while Plecturocebus discolor (family Pitheciidae) had four alleles—the largest number yet identified in a wild population of titi monkeys. For all three non‐atelid species, the middle‐wavelength (545 nm) allele was the most common. Overall, we identified genetic evidence of fourteen different visual phenotypes—seven types of dichromats and seven trichromats—among the five sympatric taxa. The differences we found suggest that interspecific competition among primates may influence intraspecific frequencies of opsin alleles. The diversity we describe invites detailed study of foraging behavior of different vision phenotypes to learn how they may contribute to niche partitioning.     

Osteophloeum platyspermum andVirola duckei (myristicaceae): newly reported as hallucinogens from Amazonian Ecuador

Quijos Quichua collaborators identifiedOsteophloeum platyspermum andVirola duckei (Myristicaceae) as sources of a psychoactive sap. This is the first reported hallucinogenic use of Myristicaceae from Ecuador. Species in Malpighiaceae and Solanaceae are more common sources of hallucinogens, but older Quichua still employ these myristicaceous species.Virola is used widely as a hallucinogen in other parts of Amazonia but there are no previous reports on the psychoactive use ofO. platyspermum. Field tests for the presence of alkaloids using Dragendorffs reagent were positive for both species. Like the Bora and Witoto in Peru, the Quijos Quichua consume myristicaceous hallucinogens orally. Most other indigenous peoples prepare psychoactive snuffs from the bark and sap.