Andean Forests Research Articles

Diversidad de plantas vasculares en bosques continuos y relictuales de Nothofagus antárctica (Nothofagaceae) en Patagonia austral

The history of Nothofagus antarctica forests in Santa Cruz is associated with significant geological and climatic disturbances. More recently, anthropic disturbances contributed to habitat fragmentation process. In the forest-steppe ecotone N. antarctica forms small forests inserted in a steppe matrix and separated from the Andean forests that are found towards the West forming continuous forest mass. Five localities of Santa Cruz were surveyed in order to study the patterns of diversity of vascular plants comparatively between relictual forests (R) and their surrounding continuous forests (A). The localities are located in a wide latitudinal gradient (47° 4’- 51° 5’ S) and experience different histories of use. The alpha and beta components of the diversity were linked to other environmental variables through a multivariate redundancy analysis (RDA). A total of 152 species were registered. The alpha diversity was evaluated using the Shannon-Wiener Index (H’). There was no significant differences (p = 0.585) between environments A and R. However, when comparing the sites the differences were significant (p <0.0001). The highest H values were recorded in the northern site, while the lowest H’ values occurred in southern site. The components analysis of global beta diversity (B ) showed lower values in the northern and southern extreme locations. In addition, while in the most austral site the component of species differentiation by nesting (Bnes) was more relevant, in the other evaluated sites the turnover component (Bsim) was predominant. The RDA shows that there is a close relationship between environmental characteristics (soil and climate) and species composition. It also shows that mean temperature is the main factor that relates localities of low similarity to each other (1 and 5). While the higher nutrient content in the soil is related to the intermediate localities (2, 3 and 4). We concluded that the latitudinal gradient had strong influences on the diversity of the understory community of N. antarctica forests. Furthermore, the intensity of the historical use of the forests can be related to a greater decrease in the vascular plant richness in relicts compared to the surrounding continuous forests. This denotes a greater sensitivity of relicts to anthropogenic disturbances and the need of an adequate conservation action.

Author Correction: Widespread but heterogeneous responses of Andean forests to climate change.

In Fig. 2 of this Article, the positive part of the y axis scale should read 0, 0.02, 0.04 instead of 0, 0.04, 0.02. This has been corrected online.

Interceptación y escorrentía del bosque altoandino en la reserva forestal protectora “El Malmo”

Los bosques tropicales son importantes a nivel mundial por su biodiversidad y los servicios ecosistémicos que proveen, son claves en el ciclo global del agua. Los cambios y presiones de origen antrópico que afectan a los bosques tropicales inciden en el papel fundamental de estos en la provisión de agua. En este trabajo se evalúa la relación de las coberturas vegetales presentes en el Bosque altoandino de la Reserva Forestal Protectora “El Malmo” con la calidad y cantidad de interceptación y escorrentía; la zona de vida analizada comprende cuatro tipos de coberturas: bosque denso altoandino, vegetación secundaria baja, plantación de latifoliadas y mosaico de pastos con espacios naturales. Se instalaron ocho montajes (dos por cobertura) compuestos cada uno de una parcela de escorrentía y un medidor de precipitación bajo el dosel; el levantamiento de datos se efectúo cada ocho días durante 24 semanas. Los resultados indican que la interceptación de la precipitación no difiere en cada cubierta, mientras que si se ve afectada la escorrentía superficial y su calidad respecto a sedimentos, cambios que obedecen fuertemente a las diferencias en las condiciones físicas del suelo. La cobertura que permite las mejores dimensiones de calidad y cantidad de agua es el bosque denso altoandino. La influencia de la intervención antrópica en el área y la presencia de invasoras afectan negativamente estas variables. Este trabajo aporta conocimiento sobre el comportamiento hidrológico de la Reserva, para su uso en la gestión forestal. Así mismo, genera información, hasta el momento inexistente, sobre la relación interceptación/escorrentía en bosques de la región Cundiboyacense, convirtiéndose en punto inicial de comparación para nuevas investigaciones en ecosistemas altoandinos.

A New Species of Eumanota Edwards (Diptera: Mycetophilidae: Manotine) from Colombia: Evidence for a Pseudogondwanan Pattern

Eumanota wolffae, sp. nov., is described from the high Andean forests of Colombia. This is the first Neotropical species of the clade of non-Manota genera of the mycetophilid subfamily Manotinae—to date known entirely from the Oriental and the northwestern Australasian regions, and in Baltic amber. With the other species of Eumanota Edwards, this species shares, among other features, a largely developed third maxillary palpomere, projecting beyond the base of fourth palpomere, with a wide sensorial pit, a flat inner face, and the last palpomere at least 4× the length of the fourth palpomere. The systematic position of the Colombian species within the Manotinae is addressed. The biogeographic significance of Eumanota in the Neotropical region is discussed, interpreted here as a concurrent incidence of a circumtropical pattern and Gondwanan distributions, in other words, a particular pattern of biogeographic pseudocongruence, referred to here as a “pseudogondwanan pattern.” This pattern is associated with an early Cenozoic tropical biota over Laurasian terranes that expanded its distribution to the south (in the Americas, Africa, and Australasia), followed by large-scale extinction of Nearctic and Palearctic representatives due to global cooling in the Neogene. A discussion is provided about the correlation between these patterns and evidence of Late Cretaceous-Paleogene tropical floras over Laurasian terranes.

The highest altitudinal record of the Mountain coati Nasuella olivacea (Gray, 1865) for Ecuador.

The Mountain coati Nasuella olivacea is a species of carnivorous mammal, several aspects of its ecology and natural history remain unknown. In Ecuador, its presence is reported in high Andean forest and paramo between 1,300 and 3,700 m a.s.l., being rare over 3,200 m. In this work, I present the extension of its altitudinal limit for Ecuador to 3,862 m a.s.l.; in addition, I report an event of a possible interaction between Tremarctos ornatus and N. olivacea.

Soil macrofauna in areas with different ages after Pinus patula clearcutting

In Andean high montane areas, the establishment of exotic tree forests changes the soil dynamics and its biodiversity. Soil macrofauna act as indicators of ecosystem successional processes, and may have an important role in ecological restoration processes after clear cutting exotic tree plantations. The aim of the present study was to understand how soil macrofaunal assemblies change in areas with different ages post clear cutting of Pinus patula, and to identify the soil physico-chemical variables that better explain these variations. The macrofauna in a high montane forest was evaluated along with that of three areas with different ages post clearcutting: 0, 2.5, and 5 years after clearcutting (Yac). The effect of soil physico chemical variables on macrofauna abundance was also evaluated. Macrofauna composition changed after clearcutting. Macrofauna abundance, richness, and diversity were lower in the 0 Yac area than in the other areas. Moreover, the macrofuna similarity to the reference forest did not increase with the years after clearcutting. This is due to the changes in soil characteristics, triggered by clearcutting. Slope, temperature, bulk density, real density, loam, pH, P, Na and K were the soil variales with a positive effect on the macrofauna abundance. These physico-chemical variables should be considered when designing restoration plans for Andean forest ecosystems. Moreover, Diplopoda, Coleoptera and Chilopoda might be useful to monitor and evaluate restoration processes after Pinus spp. clearcutting, because of their high abundance, diversity and relationship with environmental conditions.

Palm Phytoliths of Mid-Elevation Andean Forests

Palms are one of the most common tropical plant groups. They are widespread across lowland tropical forests, but many are found in higher altitudes have more constrained environmental ranges. The limited range of these species makes them particularly useful in paleoecological and paleoclimate reconstructions. Palms produce phytoliths, or silica structures, which are found in their vegetative parts (e.g., wood, leaves, etc.). Recent research has shown that several palms in the lowland tropical forests produce phytoliths that are diagnostic to the sub-family or genus-level. Here we characterize Andean palm phytoliths, and determine whether many of these species can also be identified by their silica structures. All of our sampled Andean palm species produced phytoliths, and we were able to characterize several previously unclassified morphotypes. Some species contained unique phytoliths that did not occur in other species, particularly Ceroxylon alpinium, which is indicative of specific climatic conditions. The differences in the morphologies of the Andean species indicate that palm phytolith analysis is particularly useful in paleoecological reconstructions. Future phytolith analyses will allow researchers to track how these palm species with limited environmental ranges have migrated up and down the Andean slopes as a result of past climatic change. The phytolith analyses can track local-scale vegetation dynamics, whereas pollen, which is commonly used in paleoecological reconstructions, reflects regional-scale vegetation change.

Are small abandoned plantations a threat for protected areas in Andean forests? The potential invasion of non-native cultivated species

Abandoned farms with small fruit plantations of the non-native species Prunus cerasus and Malus domestica are common in protected areas of the temperate forests of southern South America (TFSA), in Patagonia. Our aims were to determine whether an invasion of P. cerasus and M. domestica might be starting in protected areas, and whether either native or alien animal species are involved in the dispersal process. We evaluated sapling and seed spread, adult tree distribution in three habitats, and seed dispersal vectors of P. cerasus and M. domestica in “Los Alerces” National Park (Argentina). We sampled mature trees, saplings and seeds of P. cerasus and M. domesticain in two plots located next to plantations. Adult trees and mammal faeces also were searched for on roads, hiking trails, deforested areas, plots and transects opened by us. We monitored fruiting trees with cameras and we caught birds to obtain faeces. Saplings of P. cerasus were abundant and their locations were not related to adult locations, but saplings of M. domestica were rare. Ninety-two percent of P. cerasus adult trees were found in successional forest, whereas 99% of M. domestica trees were in deforested areas. Faeces of native foxes contained high number of intact seeds of both plant species studied, but we did not find any in the bird faeces. Our results indicates that P. cerasus has been invading natural habitats in protected areas of TFSA, and that foxes can be the major dispersal vectors. Further, successional forest is the most invasible habitat.

Composición y estructura florística de dos remanentes de Bosque Andino Montano Alto en el volcán Ilaló, Ecuador

Se evaluó la composición y estructura florística de dos remanentes de Bosque Andino Montano Alto, localizados en la cima del volcán Ilaló (3 190 m). Estos pertenecen a las Comunas de San Francisco de Baños-La Merced y Tola Chica. En cada remanente se establecieron 10 cuadrantes de 10×10 m (0.2 ha); se censaron todos los individuos con un DAP ≥ 2.5 cm. Un total de 533 individuos fueron registrados y clasificados en 20 familias y 40 especies. Se observó una dominancia de Oreopanax ecuadorensis (38,3 % en el remanente 1 y 42,6 % en el remanente 2), seguido de Vallea stipularis y Geissanthus pichinchae para ambos. La misma relación aparecieron en los valores más altos de área basal, donde Oreopanax ecuadorensis registró 0,85 y 0,62 m2 ; de igual forma con un IVI entre 17 % y 19 %. Los índices, alfa de Fisher, Shannon y Simpson, usados para medir la diversidad alfa, no reflejaron diferencias significativas para la conformación vegetal de los cuadrantes. Asimismo, los análisis de NMMDS y ANOSIM empleados para medir la diversidad beta no revelaron diferencias significativas entre ambos; lo que sugirió una composición vegetal continua histórica. Estudios similares son importantes para conocer, entender y conservar la vegetación remanente en los Andes ecuatorianos.

Widespread but heterogeneous responses of Andean forests to climate change.

Global warming is forcing many species to shift their distributions upward, causing consequent changes in the compositions of species that occur at specific locations. This prediction remains largely untested for tropical trees. Here we show, using a database of nearly 200 Andean forest plot inventories spread across more than 33.5° latitude (from 26.8°S to 7.1° N) and 3,000-m elevation (from 360 to 3,360m above sea level), that tropical and subtropical tree communities are experiencing directional shifts in composition towardshaving greater relative abundances of species from lower, warmer elevations. Although this phenomenon of 'thermophilization' is widespread throughout the Andes, the rates of compositional change are not uniform across elevations. The observed heterogeneity in thermophilization rates is probably because of different warming rates and/or the presence of specialized tree communities at ecotones (that is, at the transitions between distinct habitats, such as at the timberline or at the base of the cloud forest). Understanding the factors that determine the directions and rates of compositional changes will enable us to better predict, and potentially mitigate, the effects of climate change on tropical forests.

Effects of endogenous and exogenous processes on aboveground biomass stocks and dynamics in Andean forests

Tropical forests are paramount in regulating the global carbon cycle due to the storage of large amounts of carbon in their biomass. Using repeat censuses of permanent plots located at 15 sites in the Andes Mountains of northwest Colombia, we evaluate: (1) the relationship between aboveground biomass (AGB) stocks, AGB dynamics (mortality, productivity, and net change), and changes in temperature across a ca. 3000-m elevational gradient (≈ 16.1 °C); (2) how AGB mortality and AGB productivity interact to determine net AGB change; and (3) the extent to which either fine-grain (0.04-ha) or coarse-grain (1-ha) processes determine the AGB dynamics of these forests. We did not find a significant relationship between elevation/temperature and biomass stocks. The net AGB sequestered each year by these forests (2.21 ± 0.51 Mg ha−1 year−1), equivalent to approximately 1.09% of initial AGB, was primarily determined by tree growth. Both forest structural properties and global warming influenced AGB mortality and net change. AGB productivity increases with greater inequality of tree sizes, a pattern characteristic of forest patches recovering from disturbances. Overall, we find that global warming is triggering directional changes in species composition by thermophilization via increased tree mortality of species in the lower portions of their thermal ranges and that the inclusion of small-scale forest structural changes can effectively account for endogenous processes such as changes in forest structure. The inclusion of fine-grain processes in assessments of AGB dynamics could provide additional insights about the effects that ongoing climate change has on the functioning of tropical montane forests.

Effects of fragmentation on functional diversity associated with aboveground biomass in a high Andean forest in Colombia

Forest fragmentation alters the composition, structure and function of ecosystems and affects ecological processes that are fundamental for the provision of ecosystem services where functional diversity is sensitive to its effects. Analyzing the functional responses of the plant community to fragmentation can provide new approaches to its conservation and management. We analyzed whether the functional diversity of woody individuals associated with aboveground biomass (AGB) in a high Andean forest in Colombia is affected by fragmentation. Based on three fragmentation categories identified using landscape metrics, we selected ten forest fragments. Multitrait and monotrait functional diversity indexes (foliar and wood) weighted by aboveground biomass were calculated in plots of 0.1 ha in each fragment. Analysis of variance was performed, and simple linear regressions were quantified to identify the relationships between functional diversity and fragmentation. The category of large fragments had a higher average AGB than did the medium and small fragments. Fragmentation had effects on the variance of some foliar and stem traits but not on functional dominance. For the multitraits indexes, the edge contrast was negatively related with functional dispersion. The categories analyzed have similar responses in terms of functionality associated with AGB. We highlight the importance of small fragments in the maintenance of plant functional diversity and as reservoirs of AGB. We underline that small fragments are important to consider in the development of conservation and connectivity strategies.

Over-winter ecology and relative density of Canada Warbler Cardellina canadensis in Colombia: the basis for defining conservation priorities for a sharply declining long-distance migrant

SummaryThe Canada Warbler Cardellina canadensis is a steeply declining Neotropical migratory bird and &gt; 50% of its non-breeding range is within the Colombian Andes. Despite being an abundant migrant in Andean forests, the species’ elevational distribution and non-breeding ecology have yet to be studied, thereby precluding the design of effective conservation actions. During four non-breeding periods (2012–2016), we surveyed Colombia’s three Andean ranges, carrying out passive 5-minute point counts between 700 and 3,150 m asl in five habitats (mature forest, secondary growth, forest edges/riparian forest, shade coffee, sun coffee), recording the perpendicular distance, sex, foraging height, and association with mixed species flocks of Canada Warbler. Habitat variables were recorded at each point. Based on 819 passive point counts, Canada Warblers occupied elevations between 750 and 2,300 m, being more abundant between 1,000 and 2,200 m. Relative densities were higher in mature forest compared to shade coffee and secondary forest, and accordingly abundance increased with canopy height. There was no evidence for a difference in elevation or habitat use by males and females. Within forests, birds foraged at mid-levels, 5–15 m above the ground, and the probability of Canada Warblers occurring in mixed species flocks increased with elevation. Models of variation in relative density throughout the Eastern Andes showed a positive relation with cloud cover and above-ground forest biomass, implying a preference for humid, forested regions. Of the areas in the Eastern Andes with high predicted relative density, ∼ 14% overlapped with protected areas and we identify priority areas where protective measures could benefit the conservation status of the species. For maximum effectiveness, conservation actions should focus on protecting forest fragments and initiating reforestation projects at mid-elevations (1,000–2,200 m), as well as supporting agroforestry practices in humid regions of the Colombian Andes.

Are government incentives effective for avoided deforestation in the tropical Andean forest?

In order to ensure the provision of goods and services from forests, many governments have promoted less-traditional conservation initiatives such as programs of payments for ecosystem services called, more broadly, direct payments for conservation. The Socio Bosque Program (SBP) is a governmental program in Ecuador that directly provides economic incentives to rural families and local and indigenous communities who have voluntarily agreed to comply with some conservation activities. An impact evaluation method (matching) was used to assess the impact of the SBP between 2008 and 2014. This study revealed that on average, the SBP reduced deforestation by 1.5% in those forests that received the SBP’s direct payment. These forests would have been deforested if the SBP had not been implemented. Assessment of the impact of the SBP on individual and collective contracts, using the matching method, revealed that 3.4% and roughly 1% of the forest would have been deforested in the absence of the program, respectively. In other words, the protected area in the collective SBP was 1,247,500 ha and, if the SBP had not been implemented, an area of 11,227 ha would have been lost between 2008 and 2014. The 165,700 ha protected by the individual SBP, it was estimated that 5,733 ha were not deforested due to the implementation of the conservation program. Conventional estimates of the impact of the SBP tend to overestimate avoided deforestation because they do not control for observable covariates that correlate with or affect both SBP participation and deforestation. The conclusions are robust, even given potential hidden biases. The present study demonstrated that the SBP serves to mitigate the effects of climate change, especially with those contracts that are intended for individual owners.

A new species of Hyloxalus Jim&amp;eacute;nez De La Espada, 1871 &amp;#39;&amp;#39;1870&amp;#39;&amp;#39; (Anura: Dendrobatidae: Hyloxalinae) from a cloud forest near Bogot&amp;aacute;, Colombia, with comments on the subpunctatus clade

A new species of frog of the genus Hyloxalus from a high Andean forest of the central parts of the Cordillera Oriental, Colombia is recognized and described using integrative taxonomy. Using phylogenetic analyses of 2590 base pairs (bp) of mitochondrial DNA, Hyloxalus felixcoperari sp. nov. was shown to belong to a lineage of the subpunctatus clade, part of a subgroup that comprises high altitude-occurring lineages (subgroup I) and sister taxa of H. subpunctatus sensu stricto from the Bogotá plateau region. The genetic distance between both taxa is 2.1% and 5.1% for the 16S and cytochrome b gene fragments respectively. Hyloxalus felixcoperari sp. nov. is a medium-sized frog, which can be distinguished morphologically from H. subpunctatus by having dark throat and chest and unwebbed toes, and bioacoustically by emitting an advertisement call consisting of trill-like calls repeated at a rate of 50 – 104 repititions/min, with a dominant frequency ranging from 3028.9 – 3861.2 Hz. Molecular dating analysis revealed that the already known lineages of the subpunctatus clade subgroup I from the middle Cordillera Oriental of Colombia, recently diverged during the lower Pleistocene – Upper Pliocene, most probably due to environmental fluctuations. Threats and main aspects of the natural history of this new species including breeding and habitat are reported in this article.

First record of trichomycetes associated with aquatic insects from Colombian Moorland and Andean forests

This paper discusses new findings relating to the first known diversity of trichomycete gut symbionts from Colombia. All species were associated with aquatic insects in the orders Diptera and Ephemeroptera collected from various localities in the tropical Eastern Ridge of Santander. Among the reported taxa, we describe two new species, Gauthieromyces colombiensis (Harpellales), phenotypically similar to the European G. microsporus, and Paramoebidium santanderensis (Amoebidiales) characterized by retaining the cystospore attached to the growing thallus after germination. Both taxa were found in the hindgut of mayfly nymphs. We also provide 17 new geographic records of trichomycetes for Colombia. Taxonomic and biogeographic implications of these records are discussed.

Variation in Tree Community Composition and Carbon Stock under Natural and Human Disturbances in Andean Forests, Peru

Deforestation and forest degradation in Andean forests is influenced by natural and social environments including a wide elevation range and anthropogenic disturbance. Tree community composition is receiving attention as a key indicator of forest degradation. However, difference in factors affecting community composition at different elevation zones remains unclear. We aimed at elucidating factors (natural and human disturbances, and forest characteristics) that influence the variations in community composition in Andean forests. We conducted a ground-based survey setting 45 plots across a wide elevation range (ca. 600 to 3500 m a.s.l.) in Cusco region, Peru. Above ground biomass (AGB) decreased with increasing elevation. The generalized linear models for multivariate abundance data suggested that a factor affecting community composition was natural disturbance (erosion) at low elevation (&lt;1000 m), while human disturbance (infrastructure such as sheds and trails) at high elevation (≥2400 m). Within each of the different elevation zones, the AGB affected community composition only at mid elevation (1000–2400 m), whereas mean tree height showed a consistent effect on community composition across the three elevations. Our results suggest that the effects of human disturbance on community composition were more prominent at higher elevation. The results also suggest that mean tree height may have a potential to be a key measure for evaluating variations in community composition in Andean forests.

The Neotropical species of Clistopyga (Hymenoptera, Ichneumonidae, Pimplinae). Part II: the C. isayae species group, with the description of seven new species.

The New World Clistopyga isayae species group is revised. Seven species are described as new: C. crassicaudata sp. nov., C. isayae sp. nov., C. kalima sp. nov., C. nigriventris sp. nov., C. panchei sp. nov., C. splendida sp. nov. and C. taironae sp. nov. An illustrated identification key to all species of the group is provided. The Clistopyga isayae species group is composed entirely of previously undescribed species mainly from Andean forests of tropical South America.

Two new species of Pentacalia (Senecioneae, Compositae) from Peru

Two new species of Pentacalia are described herein on the basis of morphological evidence. These new findings are the result of field work and recent herbarium studies carried out at USM. Both species are very distinctive and any confusion with the other known taxa of the genus is unlikely. Both species are hitherto only known from the type locality, one collected in Junín Department (central Peru) and the other in Amazonas Department (northern Peru). They grow in Andean humid montane forests. Pictures of the respective holotypes and a distribution map are provided. Moreover, the name P. marinii is synonymized under P. herzogii, as well as P. megaphlebia to P. oronocensis.

A morphological database for 606 Colombian bird species

Colombia is the country with the highest bird diversity in the world. Despite active research in ornithology, compelling morphological information of most bird species is still sparse. However, morphological information is the baseline to understand how species respond to environmental variation and how ecosystems respond to species loss. As part of a national initiative, the Instituto Alexander von Humboldt in collaboration with 12 Colombian institutions and seven biological collections, measured up to 15 morphological traits of 9,892 individuals corresponding to 606 species: 3,492 from individuals captured in field and 6,400 from museum specimens. Species measured are mainly distributed in high Andean forest, páramo, and wetland ecosystems. Seven ornithological collections in Colombia and 18 páramo complexes throughout Colombia were visited from 2013 to 2015. The morphological traits involved measurements from bill (total and exposed culmen, bill width and depth), wing (length, area, wingspan, and the distance between longest primary and longest secondary), tail (length and shape), tarsus (length), hallux (length and claw hallux), and mass. The number of measured specimens per species was variable, ranging from 1 to 321 individuals with a median of four individuals per species. Overall, this database gathered morphological information for >30% of Colombian bird diversity. No copyright, proprietary, or cost restrictions apply; the data should be cited appropriately when used.