Podocarpus National Park Research Articles

Systematic reduction in seed rain of large‐seeded and endozoochorous species in pastures compared to forests along a tropical elevational gradient

AbstractQuestionsHow do seed rain biomass and richness change from old‐growth tropical forests to pastures at different elevations? How do seed mass and seed dispersal mode change from forests to pastures across these elevations? What implications do these changes have for the recovery of deforested areas in tropical mountains?LocationOld‐growth montane forests and livestock pastures along an elevational gradient (1,000–3,000 m a.s.l.), located at Podocarpus National Park, San Francisco Reserve and surrounding agricultural lands, Andes of southern Ecuador.MethodsWe collected seed rain for a 3‐month period using 324 traps installed at eighteen 1‐ha plots across elevations. Half of the traps were installed in nine 1‐ha forest plots, and the other half in nine 1‐ha pasture plots. For each trap, we identified the seeds and measured seed rain biomass and richness. We also recorded seed traits and calculated community‐weighted means of seed mass and seed dispersal mode (proportion of endozoochory).ResultsForests received a higher seed rain biomass than pastures, but only at the lowest elevation. Seed rain richness did not differ between habitat types at all elevations. Community‐weighted means of seed mass and the proportion of endozoochorous species declined from forests to pastures, especially at the lower elevations.ConclusionsAlthough seed rain biomass and richness were overall similar between forests and pastures, large‐seeded and endozoochorous species were generally poorly represented in the seed rain of pastures compared with that of forests. These findings show that biomass and richness of seed rain may be insufficient to quantify the restoration potential of natural seed rain in deforested areas. Information on seed traits, such as seed mass and seed dispersal mode, is important to optimize restoration efforts towards the regeneration of diverse old‐growth forests along elevational gradients in tropical mountains.

Morphometric changes on dung beetle Dichotomius problematicus (Coleoptera: Scarabaeidae: Scarabaeinae) related to conversion of forest into grassland: A case of study in the Ecuadorian Amazonia.

The conversion of forest into grassland can induce differentiation in the functional morphology of resilient species. To assess this effect, we have chosen a dung beetle Dichotomius problematicus, as a model species. We established 20 sampling points distributed along a transect for a forest and grassland located in the Podocarpus National Park in Ecuador. Four pit-fall traps were baited with pig feces per sample point and were left open for 48 h. We sexed and measured 13 morphological traits of 269 individuals. Nonmetric multidimensional scaling was carried out to evaluate the influence of habitat and sexual dimorphism on the traits. We applied a principal component analysis to evaluate the morphological features that best explain the differences between land use and sexual dimorphism. We used generalized linear models to evaluate the explanatory variables: habitat and sexual dimorphism with respect to morphological traits. Five traits contributed over 70% body thickness, Pronotum width, Pronotum length, Head width and Elytra length, following the results of a principal component analysis. Both habitat and sex influence traits. In the forest, the individuals are larger than grassland likely due to available resources, but in grassland, the structures in charge of the burial process head, protibia are larger, displaying a strong pronotum and possible a greater reproductive capacity given by spherecity. These patterns of changes in the size of beetles and their structures could reflect the conservation state of an ecosystem.

Conversion of Andean montane forest to exotic forest plantation modifies soil physicochemical properties in the buffer zone of Ecuador's Podocarpus National Park

Conversion of Andean montane forest to exotic forest plantation modifies soil physicochemical properties in the buffer zone of Ecuador's Podocarpus National Park

Trade-Offs Among Aboveground, Belowground, and Soil Organic Carbon Stocks Along Altitudinal Gradients in Andean Tropical Montane Forests.

Tropical montane forests (TMFs) play an important role as a carbon reservoir at a global scale. However, there is a lack of a comprehensive understanding on the variation in carbon storage across TMF compartments [namely aboveground biomass (AGB), belowground biomass (BGB), and soil organic matter] along altitudinal and environmental gradients and their potential trade-offs. This study aims to: 1) understand how carbon stocks vary along altitudinal gradients in Andean TMFs, and; 2) determine the influence of climate, particularly precipitation seasonality, on the distribution of carbon stocks across different forest compartments. The study was conducted in sixty 0.1 ha plots along two altitudinal gradients at the Podocarpus National Park (Ecuador) and Río Abiseo National Park (Peru). At each plot, we calculated the amount of carbon in AGB (i.e. aboveground carbon stock, AGC), BGB (i.e. belowground carbon stock, BGC), and soil organic matter (i.e. soil organic carbon stock, SOC). The mean total carbon stock was 244.76 ± 80.38 Mg ha–1 and 211.51 ± 46.95 Mg ha–1 in the Ecuadorian and Peruvian plots, respectively. Although AGC, BGC, and SOC showed different partitioning patterns along the altitudinal gradient both in Ecuador and Peru, total carbon stock did not change with altitude in either site. The combination of annual mean temperature and precipitation seasonality explained differences in the observed patterns of carbon stocks across forest compartments between the two sites. This study suggests that the greater precipitation seasonality of colder, higher altitudes may promote faster turnover rates of organic matter and nutrients and, consequently, less accumulation of SOC but greater AGC and BGC, compared to those sites with lesser precipitation seasonality. Our results demonstrate the capacity of TMFs to store substantial amounts of carbon and suggest the existence of a trade-off in carbon stocks among forest compartments, which could be partly driven by differences in precipitation seasonality, especially under the colder temperatures of high altitudes.

A new giant Pristimantis (Anura, Craugastoridae) from the paramos of the Podocarpus National Park, southern Ecuador.

A new species of frog of the genus Pristimantis is described from the paramos of the Nudo de Cajanuma, Podocarpus National Park, on the border between the provinces of Loja and Zamora-Chinchipe, Ecuador. The new species is readily distinguished from all other species of Pristimantis by its large body size (snout-vent length: 50.0–50.5 mm in adult females, 34.7–42.5 mm in adult males), thick glandular skin, large warts on flanks, prominent glandular patches on head and legs, and dark brown dorsum. This new species is among the largest and stoutest Pristimantis frogs of the high Andes. It is only known from its type locality, where it occurs in paramo bambusoid meadows at elevations between 3300 and 3400 m. It is morphologically similar to Pristimantiserythros, P.farisorum, P.obmutescens, P.orcesi, P.racemus, P.simoterus, P.simoteriscus, and P.thymelensis. Notorious morphological characters present in this new species are thick glandular patches covering dorsum and limbs and porous skin texture, which are shared with P.erythros.

The distributions of morphologically specialized hummingbirds coincide with floral trait matching across an Andean elevational gradient

AbstractMorphological trait matching between species affects resource partitioning in mutualistic systems. Yet, the determinants of spatial variation in trait matching remain largely unaddressed. Here, we generate a hypothesis that is based on the geographical distributions of species morphologies. To illustrate our hypothesis, as a study system we use hummingbirds in the tropical Andes. Hummingbirds with specialized morphologies (i.e., long or curved bills) may forage on flowers that are inaccessible to hummingbirds with generalized bill morphologies (i.e., small‐to‐medium‐sized bills with no curvature), yet the vast majority of hummingbirds have generalized bill morphologies. Thus, we propose that trait matching across space is determined by the distribution of morphological specialists. In the Andes, we observe the richness of specialized hummingbird morphotypes to peak at high and low elevations. Therefore, we hypothesize that trait matching should be most influential in predicting pairwise interactions at high and low elevations. We illustrate our hypothesis by field observations along an elevational gradient in Podocarpus National Park (Ecuador). Using Bayesian hierarchical modeling of interaction frequencies in combination with network analyzes, we found that hummingbirds at high and low elevations contributed to resource partitioning by foraging on morphologically close‐matching flowers. Moreover, at high and low elevations, hummingbirds with specialized morphologies showed a stronger tendency to visit close‐matching flowers than morphological non‐specialists did. In contrast, at mid‐elevations, hummingbirds were not attracted to morphologically close‐matching flowers. These results suggest that the spatial distribution of specialized morphotypes determines trait matching and the partitioning of interactions within hummingbird–plant communities.Abstract in Spanish is available with online material.

Five new species of the Drosophila tripunctata group (Diptera: Drosophilidae) from Podocarpus National Park, Ecuador

Five new species of the genus Drosophila Fallén, 1823 belonging to the tripunctata group are described and illustrated: D. warmi sp. nov., D. kurillakta sp. nov., D. chichu sp. nov., D. saraguru sp. nov. and D. ayauma sp. nov. from the forests of Podocarpus National Park. The first species is ascribed to subgroup II of Frota-Pessoa (1954), the second species to subgroup IV, and the last three species are not assigned to any subgroup. The flies were captured using plastic bottles containing pieces of yeast fermented banana.

Habitat requirements and differential abundance of the culpeo (Lycalopex culpaeus) in the high Andes of southern Ecuador

Basic information on culpeos’ ecology for vast regions of its range is lacking. A model was built explaining the differential abundance of culpeos in the high Ecuadorian Andes. This model considered several environmental variables and is the first approach to evaluate the culpeo’s habitat requirements in Ecuador. Fixed 1-km transects were established along paths in the highest areas of Podocarpus National Park. Here, a culpeo abundance index (AI) was calculated monthly for each transect during a year. The AI was derived from the occurrence frequency of scats, and genetic analyses were performed to confirm scat identifications. Environmental variables (e.g., climate, vegetation cover, environmental richness, and diversity) were measured at two spatial scales (microhabitat and landscape). Predictors were grouped into orthogonal factors, and general linear models (GLM) were obtained by applying a selection method of models. The results show that the highest culpeo abundances were associated with well-preserved homogeneous areas that had high levels of rainfall and extreme temperatures, with these features being characteristic of pure “paramo” at the highest altitudes. In addition, a strong positive relationship was also found with the abundance of the mountain tapir. It is suggested that the subspecies of culpeo inhabiting this region could be particularly adapted to the ecological conditions of paramo areas. If so, habitat fragmentation and ongoing changes in land use, as well as climate change, could be potential threats for the culpeo both in the study area and the entire Ecuadorian high-Andean ecosystem.

Eight new species of the genus Drosophila (Diptera: Drosophilidae) from the Andes of southern Ecuador

Eight new species of the genus Drosophila are described and illustrated: Drosophila kingmani sp. nov., Drosophila malacatus sp. nov., Drosophila millmasapa sp. nov., Drosophila pichka sp. nov., Drosophila rusaryu sp. nov., Drosophila shunku sp. nov., Drosophila shunkuku sp. nov. and Drosophila taki sp. nov. These species were collected in the cloud forests of Podocarpus National Park in the southern Ecuadorian Andes. The flies were captured using plastic bottles containing pieces of fermented banana with yeast.

Noteworthy records of Sunbittern Eurypyga helias (Pallas, 1781) (Eurypygiformes, Eurypygidae) and Black-necked Stilt Himantopus mexicanus (Statius Müller, 1776) (Charadriiformes, Recurvirostridae) from the southern Andes of Ecuador

We report the highest and southernmost documented records of 2 species of Ecuadorian birds: Sunbittern Eurypyga helias (Pallas, 1781) in the southern end of Podocarpus National Park and Black-necked Stilt Himantopus mexicanus (Statius Müller, 1776) in Yacuri National Park. Considering these and other records, both species might be expanding their ranges into the highlands, but the necessity to fill geographical, morphological, and taxonomic gaps on Ecuadorian birds remains.

Five new species of Drosophilaguarani group from the Andes of southern Ecuador (Diptera, Drosophilidae).

Five species of the genus Drosophila are described and illustrated: D.zamoranasp. n., D.quinarensissp. n., D.sachapuyusp. n., D.caxarumisp. n., and D.misisp. n. from the cloud forests of the Podocarpus National Park, in the southern Ecuadorian Andes. Flies were captured using plastic bottles containing pieces of fermented banana with yeast. All the species were found to belong to the Drosophilaguarani species-group.

Small-scale topography modulates elevational α-, β- and γ-diversity of Andean leaf beetles.

Elevational diversity gradients are typically studied without considering the complex small-scale topography of large mountains, which generates habitats of strongly different environmental conditions within the same elevational zones. Here we analyzed the importance of small-scale topography for elevational diversity patterns of hyperdiverse tropical leaf beetles (Coleoptera: Chrysomelidae). We compared patterns of elevational diversity and species composition of beetles in two types of forests (on mountain ridges and in valleys) and analyzed whether differences in the rate of species turnover among forest habitats lead to shifts in patterns of elevational diversity when scaling up from the local study site to the elevational belt level. We sampled beetle assemblages at 36 sites in the Podocarpus National Park, Ecuador, which were equally distributed over two forest habitats and three elevational levels. DNA barcoding and Poisson tree processes modelling were used to delimitate putative species. On average, local leaf beetle diversity showed a clear hump-shaped pattern. However, only diversity in forests on mountain ridges peaked at mid-elevation, while beetle diversity in valleys was similarly high at low- and mid-elevation and only declined at highest elevations. A higher turnover of species assemblages at lower than at mid-elevations caused a shift from a hump-shaped diversity pattern found at the local level to a low-elevation plateau pattern (with similar species numbers at low and mid-elevation) at the elevational belt level. Our study reveals an important role of small-scale topography and spatial scale for the inference on gradients of elevational species diversity.

Two new Andean species of Anolis lizard (Iguanidae: Dactyloinae) from southern Ecuador

ABSTRACTWe describe two new species of Anolis lizard that are sympatric on the Amazonian slopes of the Andes of southern Ecuador at elevations between 1440 and 1970 m. The new species may be distinguished from other Anolis by external anatomy, mitochondrial divergence and dewlap colour. We estimate the phylogenetic positions of the new species using Bayesian analysis of DNA sequence data including all species of Dactyloa-clade Anolis for which DNA data are available. Anolis hyacintogularis sp. nov. is sister to Anolis calimae, whereas Anolis lososi sp. nov. is sister to Anolis williamsmittermeierorum, herein reported for Ecuador for the first time. Individuals of both new species were collected within a protected area in southern Ecuador, Podocarpus National Park, which suggests that at least some populations of these species are well protected.www.zoobank.org/urn:lsid:zoobank.org:pub:E55FA804-E3FD-4412-8FEB-5234E29E272D

Farmers' Preferences for PES Contracts to Adopt Silvopastoral Systems in Southern Ecuador, Revealed Through a Choice Experiment.

This study investigates farmers' preferences to participate in payment contracts to adopt silvopastoral systems in Ecuador. A choice experiment was used to elicit preferences between different contract attributes, including differing payment amounts and land management requirements. The research was carried out in the buffer zone of Podocarpus National Park in Southern Ecuador, an area where most land is dedicated to cattle husbandry. A choice experiment was conducted to measure farmers' interest in different types of contracts. Based on existing incentive programs, contract choices varied with respect to the type of silvopastoral system, extra land-use requirements, payment levels and contract duration. In addition, contracts differed with regards to access by cattle to streams. Although the farmers did not show strong preferences for every contract attribute, the majority of farmers in the area showed interest in the proposed contracts. A latent class model identified three classes of respondents, based on their preferences for different contracts attributes or the "business as usual" option. The results suggest that farmland area, agricultural income, and landowners' perceptions of environmental problems provide a partial explanation for the heterogeneity observed in the choices for specific contracts. Participation might increase if contracts were targeted at specific groups of farmers, such as those identified through our latent class model. Offering flexible contracts with varying additional requirements within the same scheme, involving farmers from the start in payments for environmental services design, and combining payments for environmental services with integrated conservation and development projects may be a better way to convince more farmers to adopt silvopastoral systems.

Feeding ecology of the culpeo in southern Ecuador: wild ungulates being the main prey

This study details for the first time the food habits of the culpeo or Andean fox (Lycalopex culpaeus) in high areas of the Ecuadorian Andes during a complete annual cycle. Our objective was to identify prey species, calculate their contribution to diet and test for temporal variation. In total, 304 Andean fox scats were collected within the Podocarpus National Park (Loja province, southern Ecuador). By analysing the content of scats 413 prey items were identified and classified into eight prey groups. Sub-sequently, the frequency of occurrence (FO) for each prey group was calculated per month together with the relative contribution of estimated consumed biomass (CB). In addition, the Shannon-Wiener’s index was calculated as a measurement of monthly diet diversity. The results show a diet dominated by cervids belonging to the Mazama and Pudu genus (70% FO), followed by small mammals (30% FO), large rodents (12% FO), carnivorous species (10% FO) and lagomorphs (8% FO). There was temporal variation in the consumption of both deer and small mammals. Cervids also provided the major part of the consumed biomass (70% CB), the remaining prey categories each accounted for less than 11% CB. Negative correlations in consumption were observed between cervids and two other groups, rabbits and small mammals. Trophic diversity values fluctuated throughout the year showing a mean of 1.7. The results obtained show a diets very different from those previously reported; deer being the bulk of the diet instead of rodents or other mammals. The consumption of carnivorous species in the area was also high in comparison with other regions. Overall, this study clearly demonstrates that the culpeo is an important top predator in the high-Andean ecosystem.

Evaluation of Global Positioning System telemetry collar performance in the tropical Andes of southern Ecuador

The objective of this study was to evaluate if canopy cover, topographic obstruction of the sky, and differences among vegetation type affected performance of global positioning system (GPS) telemetry in southern Ecuador. A GPS collar was placed at 30 test sites in Podocarpus National Park, Ecuador, and we estimated canopy cover and topographic obstruction at each site. The mean fix success rate was 87.7% (SD=22.3%), and the mean location error for test sites was 9.7m (SD=4.17m). Canopy cover significantly reduced the performance of GPS telemetry in our study area both in terms of location error and fix acquisition rate. However, topographic obstruction did not significantly influence location errors or fix acquisition rate. Screening data to remove less accurate, two-dimensional fixes resulted in an 11% data loss and reduced the mean location error by 3.8m. Understanding how habitat variables influence fix acquisition and location errors of GPS collars will assist researchers in evaluating potential biases and developing methods to correct for the effect of such biases on analyses of habitat use and animal movements in the tropical Andes in southern Ecuador.

Elevation and topography influence community structure, biomass and host tree interactions of lianas in tropical montane forests of southern Ecuador

AbstractQuestionsHow does the structure of liana communities (diameter, density and biomass) in tropical montane forests vary along elevation and topographic gradients? How do patterns of tree infestation vary with elevation? Is tree diameter growth reduced by lianas in tropical montane forest?LocationTropical Andean forests (1000–3000 m a.s.l.) in the San Francisco Reserve and in the Podocarpus National Park, southern Ecuador.MethodsAll lianas (DBH ≥ 1 cm) were censused in 54 permanent plots (20 × 20 m) equally distributed between three study sites (1000, 2000 and 3000 m a.s.l.) and three topographic positions (lower, mid and upper slope) per site (six replicate plots at each site by position combination). The DBH and number of lianas hosted was recorded for all trees (DBH ≥ 10 cm). Liana biomass was estimated using allometric equations. ANOVAs were used to test for effects of elevation and slope positions on liana parameters and proportion of trees infested. The relationships between liana biomass and tree parameters and environmental parameters were analysed with partial least squares regression. We used the available literature data to perform a regression analysis of liana biomass in response to elevation in humid tropical old‐growth forests between sea level and 3000 m a.s.l.ResultsLiana diameter, density and biomass all decrease with elevation. The decreasing liana biomass agrees with results from previous studies of liana biomass in other humid tropical forests, indicating a decrease of 0.18 Mg·ha−1 liana biomass per 100 m of elevation gain. Topographic variation leads to thinner but more abundant stems upslope; there was no effect of topographic position on liana biomass. Liana biomass and liana infestation are both positively correlated with host tree DBH at every elevation. Tree diameter growth is reduced by liana infestation; the proportion of infested trees is lower in Andean montane forests than in tropical lowland forests.ConclusionsLiana biomass distribution and tree infestation vary significantly with elevation. Biomass of lianas and relative contribution of lianas to total above‐ground biomass both decrease with elevation. Topographic effects likely result from higher soil fertility at lower slope positions.

Notes on the Tropical Andean GenusDisceratus(Orthoptera, Tettigoniidae, Pseudophyllinae), the Probable Male ofD. nubiger,and Its Calling Song

A male Disceratus specimen found in cloud forest of Podocarpus National Park in southernmost Ecuador is apparently conspecific with Disceratus nubiger Scudder 1869, known only from the female holotype, collected one and a half centuries ago on slopes of the volcano Antisana. The song of this male could be recorded, confirming the identification of field recordings as well as additional acoustic records with an ultrasound detector at the same site. This incessant calling song, a series of steadily repeated short clicks with a sharp peak at 20 kHz, easily reveals the presence of this short-legged and brachypterous katydid — it lives in bamboo thickets within cloud forest, where individuals are very difficult to find. More fieldwork and nocturnal acoustic monitoring in the tropical Andes will be essential to shed light on the distribution and life history of this practically forgotten genus and its species, some of them probably still undiscovered. Disceratus is recognized as full genus rather than a subgenus of Gnathoclita.

Species of Hybotinae from Podocarpus National Park, Ecuador (Diptera, Empidoidea, Hybotidae)

The Hybotinae of the Podocarpus National Park were studied. Fourteen species are recorded and nine new species are described and illustrated: Euhybus pectinifemursp. nov., Neohybos fuliginosussp. nov., Neohybos globosussp. nov., Neohybos rostratussp. nov., Neohybos serratussp. nov., Neohybos spinosussp. nov., Syndyas longiventrissp. nov., Syneches flavithoraxsp. nov. and Syneches polletisp. nov. A key to Neohybos species from Ecuador is also presented.

Exploring the Leaf Beetle Fauna (Coleoptera: Chrysomelidae) of an Ecuadorian Mountain Forest Using DNA Barcoding.

BackgroundTropical mountain forests are hotspots of biodiversity hosting a huge but little known diversity of insects that is endangered by habitat destruction and climate change. Therefore, rapid assessment approaches of insect diversity are urgently needed to complement slower traditional taxonomic approaches. We empirically compare different DNA-based species delimitation approaches for a rapid biodiversity assessment of hyperdiverse leaf beetle assemblages along an elevational gradient in southern Ecuador and explore their effect on species richness estimates.Methodology/Principal FindingsBased on a COI barcode data set of 674 leaf beetle specimens (Coleoptera: Chrysomelidae) of 266 morphospecies from three sample sites in the Podocarpus National Park, we employed statistical parsimony analysis, distance-based clustering, GMYC- and PTP-modelling to delimit species-like units and compared them to morphology-based (parataxonomic) species identifications. The four different approaches for DNA-based species delimitation revealed highly similar numbers of molecular operational taxonomic units (MOTUs) (n = 284–289). Estimated total species richness was considerably higher than the sampled amount, 414 for morphospecies (Chao2) and 469–481 for the different MOTU types. Assemblages at different elevational levels (1000 vs. 2000 m) had similar species numbers but a very distinct species composition for all delimitation methods. Most species were found only at one elevation while this turnover pattern was even more pronounced for DNA-based delimitation.Conclusions/SignificanceGiven the high congruence of DNA-based delimitation results, probably due to the sampling structure, our study suggests that when applied to species communities on a regionally limited level with high amount of rare species (i.e. ~50% singletons), the choice of species delimitation method can be of minor relevance for assessing species numbers and turnover in tropical insect communities. Therefore, DNA-based species delimitation is confirmed as a valuable tool for evaluating biodiversity of hyperdiverse insect communities, especially when exact taxonomic identifications are missing.