Andean Forests Research Articles

Miconiagaragoana - Melastomataceae: A new rheophytic species from the eastern Andes of Colombia.

A new species, Miconiagaragoana, from riparian environments of the northern Cordillera Oriental of Colombia, is described. This is the second species exclusive to rheophytic conditions that grows in the Andean forest in Colombia and is characterized by the presence of stellate-lepidote trichomes on young structures and inflorescences, terminal inflorescences, 4-merous (rarely 5-merous) flowers, oblong-subulate anthers with an apical pore and 2-locular ovary. The differences with other rheophytic species occurring in Colombia are noted and it is argued that it is related to other Andean species with bluish-green ripe fruits such as M.squamulosa and M.symplocoidea. This new species is so far known only from Colombia and its threat category is suggested as Critically Endangered" (CR).

Structure of plant-frugivorous bird interaction networks in two high Andean forests of southwestern Colombia

Structure of plant-frugivorous bird interaction networks in two high Andean forests of southwestern Colombia

From Stand to Forest: Woody Plant Recruitment in an Andean Restoration Project.

The growing deforestation of tropical forests requires the implementation of restoration actions capable of assisting the recovery of biodiversity and the functioning of these ecosystems. This research aimed to identify the environmental factors that influence the abundance and diversity of woody plant recruitment in an Andean forest restoration project in Medellin (Colombia). Data from woody plant individuals taller than 80 cm were collected in 22 plots of 200·m-2. The environmental factors selected were edaphic variables, plantation structure, slope, elevation, prior land use, and landscape forest cover. Generalized linear models (GLM) were used to analyze recruitment densit and Linear Mixed Models (LMM) to assess recruited species richness, diversity, and dominance. Woody plant recruitment attributes in our study area were similar to those of secondary succession in an Andean forest, but planted trees contributed little to recruitment density and diversity. While recruitment density was affected by slope, canopy closure, and landscape forest cover, recruitment diversity was influenced by physical (bulk density) and chemical (pH, aluminum, Cation Exchange Capacity) edaphic factors, planted tree diversity (species richness and composition), canopy closure, and the mortality rate of planted trees. We conclude that sites with lower mortality rates of planted trees and denser canopies enhance both recruitment density and diversity, indicating a synergy between active restoration and passive regeneration processes.

Epidendrum manusalinasiae (Orchidaceae: Laeliinae), new species from the high Andean forests of Manu National Park, Cusco, Perú

We describe and illustrate a new species of Epidendrum from the high Andean forests of Manu National Park, Cusco. Epidendrum manusalinasiae belongs the Saxicola group. Information on its distribution, habitat, phenology, and conservation status is provided. The new species is compared with E. churubambense, E. herreranum and E. tetartociclium from which it is distinguished by having leaves elliptic to widely elliptic, flowers pale yellow to green, sepals sometimes tinged red-brown, column and calli creamy yellow, lip disc with large, fleshy thickened, forming wide cordiform platform, wider than mid-lobe and reaching its base and mid-lobe whit distal portion plicated forward, whit a sub-lobed appearance in natural position.

Evaluating the performance of Polylepis incana seeds: reassessing their potential for restoration and conservation of high Andean forests

The use of high‐quality seeds is essential for reforestation and ecosystem restoration; however, few Andean species have been assessed to determine factors influencing seed quality. Most Andean native tree species used for restoration are propagated from naturally regenerated seedlings or cuttings. We evaluated the seed quality (germination, viability, vigor, and physical characteristics) of a central Peruvian population of the keystone high Andean tree species Polylepis incana (quinual) in relation to the mother tree and microsite characteristics. Our analysis, using 12,912 seeds categorized by weight, included germination tests in incubator, tetrazolium tests, and vigor test (germination in nursery conditions). Results showed a mean germination rate of 30.9 ± 22.4%, with a significant proportion of damaged (38.7%), empty (19.1%), and non‐viable (12.7%) seeds. Heavier seeds exhibited the highest germination, while dasometric variables of the mother tree were not related to seed performance. However, solar incidence and slope negatively impacted germination. We conclude that seed quality may be higher than previously estimated, supporting the need to re‐evaluate and promote the use of seeds for propagating P. incana. Furthermore, since the characteristics of mother trees seem not to be relevant for this species and only solar incidence and terrain slope seem to negatively affect seed quality, we consider it important to change the paradigm from identifying individual seed trees to identifying seed forests. Conservation of natural forests as primary seed sources should be the foundation of future reforestation and restoration efforts in the high Andes.

Wood anatomical acclimation in the endemic genus Polylepis in Peruvian Andean forests

Wood anatomical acclimation in the endemic genus Polylepis in Peruvian Andean forests

BIRD COMMUNITIES RESPOND TO THE SEASONAL FRUIT AND FLOWER AVAILABILITY IN A FRAGMENTED TROPICAL ANDEAN LANDSCAPE

Fire is one of the main causes of fragmentation in tropical Andean forests. Fragmentation can influence plant reproductive phenology, which in turn affects bird communities. In the Bolivian Yungas, we investigated how the seasonal availability of fruits and flowers affects bird richness, abundance and bird community composition in forest edges and adjacent bracken (Pteridium ferns) dominated areas. We captured birds with mist nets at eight sites during the dry, transition and wet seasons, and recorded fruit and flower availability through phenological observations and plant collections. We examined variation in species richness and abundance using generalized linear mixed-effects models, and bird species composition in each season using multivariate analyses. Fruit availability was higher in the transition and wet seasons, and lowest in the dry season, while flower availability did not differ among seasons. Bird species richness and abundance were significantly higher in bracken areas, although there was significantly lower fruit availability than at the forest edge, and these were mainly generalist bird species that may be tolerant to disturbance. Total bird abundance increased with higher fruit availability in both habitats, and with flower availability at the forest edge. Bird species composition differed between forest edges and bracken areas in the transition and the wet seasons, being influenced by fruiting and flowering phenology in the dry and transition seasons, and elevation in all seasons. Our results show the varying seasonal influence of plant reproductive phenology on avian communities of disturbed habitats, although other large scale factors associated with fragmentation may also shape bird communities.

Habitat Suitability in High Andean Butterflies: The Role of Land Cover in the Occurrence and Conservation of Species.

High Andean butterflies in northern South America are subject to landscape change processes. Our study used models to assess the habitat suitability of three Satyrinae species in the Upper Bogotá River Basin, Colombia. These three species include Pedaliodes polla (Thieme), Pedaliodes phaea (Hewitson), and Pedaliodes phaeina (Staudinger), the last two are endemic to Colombia. We used MaxEnt software to assess the habitat quality of these species, analyze the bioclimatic requirements that most influence them, and propose priority conservation areas. Our results indicated that, in most cases, the contribution of cover is more significant than 60%, so this variable determines the habitat capacity to support the species under study. We identified that the areas with suitable habitats are reduced with values less than or equal to 25% and are located in areas with a medium degree of intervention, which allows the species to occur. On the other hand, the climatic variables with the most significant contribution to the models were Temperature Seasonality and Precipitation of Driest Quarter (May-July). Conservation efforts must be focused on the most suitable areas, given the reduction in habitat for these species. Our research emphasizes the need to safeguard well-connected remnants of the high Andean forest and natural cover in agricultural matrices to counter the impact of agricultural expansion.

Complete phylogeny of Micrathena spiders suggests multiple dispersal events among Neotropical rainforests, islands and landmasses, and indicates that Andean orogeny promotes speciation.

The Neotropical region is the most diverse on the planet, largely owing to its mosaic of tropical rainforests. Multiple tectonic and climatic processes have been hypothesized to contribute to generating this diversity, including Andean orogeny, the closure of the Isthmus of Panama, the GAARlandia land bridge and historical connections among currently isolated forests. Micrathena spiders are diverse and widespread in the region, and thus a complete phylogeny of this genus allows the testing of hypotheses at multiple scales. We estimated a complete, dated phylogeny using morphological data for 117 Micrathena species and molecular data of up to five genes for a subset of 79 species. Employing event-based approaches and biogeographic stochastic mapping while considering phylogenetic uncertainty, we estimated ancestral distributions, the timing and direction of dispersal events and diversification rates among areas. The phylogeny is generally robust, with uncertainty in the position of some of the species lacking sequences. Micrathena started diversifying around 25 Ma. Andean cloud forests show the highest in-situ speciation, while the Amazon is the major dispersal source for adjacent areas. The Dry Diagonal generated few species and is a sink of diversity. Species exchange between Central and South America involved approximately 23 dispersal events and started ~20 Ma, which is consistent with a Miocene age for the Isthmus of Panama closure. We inferred four dispersal events from Central America to the Antilles in the last 20 Myr, indicating the spiders did not reach the islands through the GAARlandia land bridge. We identified important species exchange routes among the Amazon, Andean cloud forests and Atlantic forests during the Plio-Pleistocene. Sampling all species of the genus was fundamental to the conclusions above, especially in identifying the Andean forests as the area that generated the majority of species. This highlights the importance of complete taxonomic sampling in biogeographic studies.

Control of invasive conifers in temperate Andean forests promotes native vegetation restoration, but requires continuous management

Non-native conifers have been planted widely because of their growth potential and wood quality. However, many of them have become invasive in the introduced ranges. In Chile, the initial introduction of non-native conifers helped the recovery of degraded land, but today some pine species present a high invasion risk when they are not properly managed, leading to detrimental impacts on natural ecosystems and biodiversity. Such is the case of Douglas fir (Pseudotsuga menziesii), a species listed as invasive in south-central Chile, as well as in many other countries, when it establishes beyond the original plantation range. The main goal of this research was to characterize the invasion pattern of P. menziesii within a recently-declared protected area nearby the Conguillío National Park in the Andes Cordillera. We aimed at determining the key factors that promote the invasion of P. menziesii outside the original plantations. We established five 1,000 m2 sampling transects (i.e., 100×10 m), considering two invasion conditions: (i) within the native forest and (ii) far into open scrub areas, both adjacent to P. menziesii plantations. We measured forest structure, soil nutrients, the floristic composition and pine regeneration before and after controlling the invasion within each study conditions. We found that P. menziesii density and soil nutrient availability in the soil decreased with the distance from the plantation. In addition, an increase in native species cover was found after removing pines, but also noted the ability of P. menziesii to readily re-invade the native forest after removal. These results indicate the need for continuous control of P. menziesii, especially inside the native forest at the early stages of invasion. We discuss the need for better plantation management to prevent its spread into natural areas and protect native forests from non-native conifers invasion.

The bright side of the moon: vocal activity of the Black-banded owl (Strix huhula huhula) in the Yungas Andean forests of Argentina

ABSTRACT In recent years, passive acoustic monitoring (PAM) has become one of the main tools for natural history and behavior studies in nocturnal birds. In this study, we explored the Black-banded owl (Strix huhula huhula) vocal activity in the Yungas Andean forests from northwestern Argentina, using one autonomous recording unit from September 2017 to February 2018. We found higher vocal activity on nights with high lunar illumination (76–100%), mainly concentrated during the early night: between 22:00–23:00 h; approximately 1–2 hours after sunset. This study shows the first acoustic phenology pattern of the black-banded owl during a year-round survey with the use of PAM in the Yungas. We highlight the importance of this type of research to gain knowledge on the vocal behavior of Neotropical nocturnal birds. Additionally we highlight the necessity of incorporating PAM, combined with occupation models, to evaluate the population status of threatened nocturnal bird species.

Seed permeability: an essential trait for classifying seed dormancy type

Abstract Seed dormancy in plants can have a significant impact on their ecology. Recent work by Rojas-Villa and Quijano-Abril (2023) classified the seed dormancy class in 14 plant species from the Andean forests of Colombia by using germination trials and several microscopy techniques to describe seed anatomy and morphology. The authors conclude that Cecropia species have both physical and physiological dormancy (of which they call physiophysical dormancy) based on seed morphology and mean germination times of over 30 days. Here, we present seed permeability and germination data from neotropical pioneer tree species: Ochroma pyramidale, Cecropia longipes, and Cecropia insignis, as well as Cecropia peltata (present in Rojas-Villa and Quijano-Abril, 2023), to demonstrate that Cecropia species do not exhibit dormancy and also have high levels of seed permeability. We find that the mean germination time for all three Cecropia species in our study was less than 30 days. This suggests a need for reporting the conditions in which germination trials take place to allow for comparability among studies and using seed permeability tests to accurately identify the physical dormancy class of seeds. Further, we present data from the literature that suggests that dormancy is not a requirement for seed persistence in the seed bank.

Linking landscape and genetic variation in the heterogeneous Yungas Andean forest' hotspot: a multi taxa approach

AbstractAimThe factors that influence the diversity of Yungas Andean forest remain unexplored. Our study seeks to investigate the impact of key isolating factors on the genetic structure of multiple taxa, testing for four hypotheses: isolation by distance (IBD), isolation by resistance due to topography (IBRtopo), isolation by resistance due to habitat suitability (IBRsuit) and isolation by environmental dissimilarity (IBE).LocationYungas Andean forest.TaxonTetrapoda.MethodsWe analysed a dataset consisting of 477 Cyt‐b sequences from 138 localities, encompassing 13 species. Through multiple matrix regression, Moran Spectral Randomization of Mantel and GDM analyses, we tested the impact of each extrinsic predictor on observed genetic variation and determined the effect size of environmental variation on genetic divergence. Additionally, we investigated the spatial distribution of lineages within the study species.ResultsThe genetic variation within the Yungas exhibited varied responses that correspond to the regional landscape heterogeneity. We identified different isolating factors as the main predictor for specific species: IBD for Akodon spegazzinii; IBRtopo for certain small mammals' species; IBE for Thylamys cinderella and Oligoryzomys brendae; and IBRsuit for Calomys fecundus, Oreobates barituensis and Melanophryniscus rubriventris with some considerations. Furthermore, our results support the presence of a latitudinal pattern in the distribution of genetic lineages.Main ConclusionsThe heterogeneous landscape of the Yungas Andean forest posed varied effects on genetic variation. The effect of topography and continuity of suitable habitats over vertebrate dispersal shapes the genetic diversity, in particular topography acts either as a barrier or as corridor, while habitat suitability resistance mainly shapes endemism genetic structure; local climate represents a strong genetic promoter in transition zones; and the effect of geographic distance is less evident when considering other landscape promoter of genetic divergence. This reinforces the understanding that the complex interplay of environmental and historical factors contributes to the observed patterns of genetic diversity in this region.

Campylocentrum luzmariae (Vandeae, Orchidaceae), a new species from the Andean cloud forest of Colombia

The Andean forests of Colombia harbor high plant biodiversity, especially orchids. Here, we propose and describe a new species of Campylocentrum from the cloud forests of the eastern Andean slopes of Caquetá, Colombia. The new species resembles C. alvesii, from which it differs by the longer lip with obtuse lateral lobes, and C. asplundii, from which it differs by inflorescences shorter than the leaves, trilobed lip, and strongly recurved spur.

Indicators sandflies and environment associated to spatial landscaping change in Chocó Biosphere Reserve UNESCO.

Sandflies are vector insects associated with terrestrial forest ecosystems; in the Ecuadorian Andes, they participate in the transmission of human cutaneous leishmaniasis. This geographical area represents an opportunity to evaluate the role of sandflies as bioindicators of the degree of intervention of tropical humid forest ecosystems (THF) associated with changes in the ecology of the local landscape. CDC-light traps were used for collecting adult sandflies in February 2020 in a humid tropical forest within the Chocó Biosphere Reserve. All species were identified using morphological keys. Analysis data about abundance, richness, species accumulation, diversity index, species composition communities, species sex proportion, spatial sandflies environmental, Renyi's Diversity Profile were performed to compare six spatial habitats in Mashpi locality, Ecuador. Sandflies were collected (n-1435); the main species are represented by Trichophoromyia reburra, Nyssomyia trapidoi, Psathyromyia aclydifera, Psychodopygus panamensis and Lutzomyia hartmanni. Only Th. reburra is associated with not intervened forest, while the other three species are associated with intervened forest within Mashpi in the Choco Biosphere Reserve. The secondary forest has major sandflies' richness, while the primary forest exhibits major abundance. Th. reburra is a sandfly restricted to the Andean Forest and is a bioindicator of the high environmental health quality of the forest, while Ny. trapidoi and Pa. aclydifera are bioindicators of environmental disturbances in the forest. Additionally, Ps. panamensis, Lu. hartmanni and Ny. trapidoi are bioindicators of human impact and the risk of leishmaniasis.

Mapping the way: identifying priority potential corridors for protected areas connectivity in Colombia

Colombia has experienced alarming rates of deforestation, posing a threat to forest biodiversity both inside and outside protected areas. Furthermore, a decline in ecological connectivity can potentially disrupt vital ecological processes such as pollination, gene flow, breeding, seed dispersal, among others. To address this issue at a national scale, it is crucial to identify and conserve a comprehensive network of ecological corridors.In this study, we identified high priority potential ecological corridors linking protected areas in Colombia. We categorized a representative set of 16 threatened mammal species into four ecological profiles. Then, we used Least Cost Path (LCP) analysis to model potential corridors between protected areas as those that minimized resistance for forest species dispersal. To prioritize conservation efforts, we applied the decrease in the Probability of Connectivity index (dPC) to identify corridors with the highest priority.Our findings emphasize the importance of preserving large forest patches within protected areas for species inhabiting lowland and sub-Andean forests. However, for species residing in Andean and high Andean forests, restoration measures (e.g., increasing forest cover) between protected areas are needed to enhance landscape permeability and facilitate their dispersal, thereby contributing to their conservation.Our results have practical implications for decision-makers involved in conservation efforts. These findings can aid in identifying conservation priorities for existing protected areas and their surrounding forest habitats in Colombia. Additionally, we provided expert-based resistance values for different forest mammals that can be further used in other large scale connectivity analyses, including other countries where these species inhabit.

Above‐ and belowground strategies of tropical montane tree species are coordinated and driven by small‐scale nitrogen availability

Abstract The question whether the strategies of above‐ and belowground plant organs are coordinated as predicted by the plant economics spectrum theory is still under debate. We aim to determine the leading dimensions of tree trait variation for above‐ and belowground functional traits, and test whether they represent spectra of adaptation along a soil fertility gradient in tropical Andean forests. We measured leaf, stem and fine root functional traits, and individual‐level soil nutrient availability for 433 trees from 52 species at three elevations between 1000 and 3000 m a.s.l. We found close coordination between above– and belowground functional traits related to the trade‐off between resource acquisition and conservation, whereas root diameter and specific root length formed an independent axis of covarying traits. The position of a tree species along the acquisition–conservation axis of the trait space was closely associated with local soil nitrogen, but not phosphorus, availability. Our results imply that above‐ and belowground plant functional traits determine at which edaphic microhabitats coexisting tree species can grow, which is potentially crucial for understanding community assembly in species‐rich tropical montane forests. Read the free Plain Language Summary for this article on the Journal blog.

A new species of terrestrial toad of the Rhinellafestae group (Anura, Bufonidae) from the highlands of the Central Cordillera of the Andes of Colombia.

The genus Rhinella (Bufonidae) comprises 92 species of Neotropical toads. In Colombia, Rhinella is represented by 22 recognized species, of which nine belong to the Rhinellafestae group. Over the past decade, there has been increasing evidence of cryptic diversity within this group, particularly in the context of Andean forms. Specimens of Rhinella collected in high Andean forests on both slopes of the Central Cordillera in Colombia belong to an undescribed species, Rhinellakumandaysp. nov. Genetic analyses using the mitochondrial 16S rRNA gene indicated that the individuals belong to the festae species group. However, they can be distinguished from other closely related species such as Rhinellaparaguas and Rhinellatenrec by a combination of morphological traits including the presence of tarsal fold, a moderate body size, and substantial genetic divergence in the 16S rRNA gene (> 5%). Through this integrative approach, the specimens from the Central Cordillera of Colombia are considered an evolutionary divergent lineage that is sister to R.paraguas, and described as a new species. Rhinellakumandaysp. nov. is restricted to the Central Cordillera of Colombia inhabiting both slopes in the departments of Caldas and Tolima, in an elevational range between 2420 and 3758 m. With the recognition of this new species, the genus Rhinella now comprises 93 species with 23 of them found in Colombia, and ten species endemic to the country.

Rediscovery of the Neotropical orchid Porroglossum parsonsii and recommendations for its conservation

Abstract Understanding the distribution and habitat requirements of species is crucial for designing conservation actions, yet this information is not available for many plant species. We report the first confirmed wild populations of Porroglossum parsonsii, which, because of its horticultural value, is commercialized in national and international markets, from where it was first described to science. Our large-scale survey of 341 10 × 30 m plots spanning Andean forests, paramo habitats and pasturelands in Colombia suggests that P. parsonsii has a restricted geographical distribution in Andean forests with high forest cover (71.4–86.2%), where it occurs in low numbers (5–17 individuals per plot). Because of its market value (USD 18–20 per plant) there is a risk the species could be collected illegally, and therefore the habitat of the species in the Santuario de Fauna y Flora de Iguaque requires appropriate conservation.

Spatial extent predicts Andean epiphyte biodiversity responses to habitat loss and fragmentation across human‐modified landscapes

AbstractAimHuman‐driven landscape processes such as habitat loss and fragmentation act on biodiversity, but their effects are mediated by the spatial scale at which they are observed. We aim to analyse the scale‐of‐effects (direction and spatial extent) of landscape‐scale processes that best explain species richness and abundance across epiphyte communities.LocationNeotropics, Northern Andes, Colombia, Eastern cordillera.TaxonVascular epiphytes, Orchidaceae.MethodsWe used field data to unravel the scale‐of‐effect of three landscape processes—habitat loss (forest cover), fragmentation (number of patches) and edge effects (edge density)—on epiphyte biodiversity. Vascular epiphytes were sampled in the understorey across 141 plots within 23 Andean forests in the eastern Colombian cordillera We focused on the community‐level responses (species richness and total abundance) of the hyperdiverse vascular epiphyte communities using generalized linear mixed models to quantify the direction and the spatial extent of the scale‐of‐effects.ResultsHabitat loss and edge effects act at fine spatial extents (scale‐of‐effects = 200 m), predicting low species richness and abundance across groups. Likewise, fragmentation negatively impacts communities, but operates at larger spatial extents (scale‐of‐effects = 2000–2400 m radius). The detection of these effects is contingent upon the spatial extent and specific landscape processes involved. Models of habitat loss within a spatial extent of 800–1500 m (large confidence intervals), fragmentation below 300 m, and edge effects above 800 m show weak statistical support (marginal r2 = 0.02–0.1). Thus, the impacts of these landscape processes may be overlooked if studied at inadequate spatial extents.Main ConclusionsWe showed that habitat loss, fragmentation and edge effects all play a negative role on understorey epiphytic communities, but their detectability is scale dependant. The scale‐of‐effects can assist landscape designs that are beneficial for epiphytic communities, by preserving forest cover, and reducing fragmentation and exposure to edge effects at small scales (200–300 m). Conversely, landscape‐scale actions directed at reducing habitat loss and fragmentation function at larger spatial extents (>2000 m). Selecting a priori or inadequate spatial extents of analysis can obscure the detectability of landscape processes.