Andean Cloud Forest Research Articles

Conservation of forest biodiversity and ecosystem properties in a pastoral landscape of the Ecuadorian Andes

High Andean cloud forests are home to a diversity of unique wildlife and are important provid- ers of ecosystem services to people in the Andean regions. The extent of these cloud forests has been widely reduced through conversion to pasture for livestock, which threatens the forests' ability to support biodiversity and provide ecosystem services. This paper explores whether impacts on woody plant biodiversity and four ecosystem properties (woody plant species richness, juvenile timber tree abundance, soil organic matter content and soil moisture) from converting forest to pasture can be mitigated if some woody forest vegetation is maintained within pastures. Woody vegetation in pastures was found to conserve those woody plant species that are more tolerant to exposure and grazing, but conservation of the high montane cloud forest community required areas of forest from which livestock were restricted. The sampled sites clustered according to woody plant species cover; these clusters represented a gradient from pasture with patches of shrubs to mature forest. Clusters differed in both woody plant species richness and number of juvenile timber trees whereas soil organic matter and soil moisture were observed to be similar among all clusters. This suggests that the different habitats may have some equivalent ecosystem properties. We conclude that the presence of woody vegetation in pastures may reduce some of the impacts of converting forest to pasture, but should not be considered a substitute for protecting large areas of forest, which are essential for maintaining woody plant species diversity in high Andean cloud forest.

Breeding biology of the Spotted Barbtail (Premnoplex brunnescens)

The Spotted Barbtail (Furnariidae) is poorly studied but shows some extreme traits for a tropical passerine. We located and monitored 155 nests to study this species for 7 years in an Andean cloud forest in Venezuela. Spotted Barbtails have an unusually long incubation period of 27.2 ± 0.16 days, as a result of very long (3–6 hr) off-bouts even though both adults incubate. The long off-bouts yield low incubation temperatures for embryos and are associated with proportionally large eggs (21% of adult mass). They also have a long nestling period of 21.67 ± 0.33 days, and a typical tropical brood size of two. The slow growth rate of the typical broods of two is even slower in broods artificially reduced to one young. Nonetheless, the young stay in the nest long enough to achieve wing lengths that approach adult size.

A New Species and Two New Subspecies of Adelpha Hübner, [1819] From the Tropical Andes (Nymphalidae: Limenitidinae)

ABSTRACT. A new species, Adelpha margarita Willmott & Hall, new species, is described from Andean cloud forest habitats from southern Ecuador to Bolivia. Adelpha margarita garleppi Willmott, new subspecies, is described for southern Peruvian and Bolivian individuals, which differ from the nominate subspecies in having complete orange postdiscal bands on the dorsal surface. The new species differs from related species in the Adelpha serpa group in wing pattern, DNA sequence data and habitat. A lectotype is designated for Adelpha seriphia therasia Fruhstorfer, because the type series of this name contains individuals of both A. seriphia and A. margarita. Neighbor-joining and maximum parsimony analyses of 579 bp of the mitochondrial cytochrome oxidase I (COI) ‘barcode’ region, for 27 Adelpha specimens representing 9 species and 13 taxa, suggest that the closest relative to A. margarita is the Central American to west Andean taxon A. seriphia godmani Fruhstorfer. The DNA sequence data, coupled with a re-analy...

Forest patches and the upward migration of timberline in the southern Peruvian Andes

Montane plant species around the globe are predicted to shift their distributions upslope in response to increasing temperatures associated with climate change. In the tropical Andes, which are one of the most diverse and threatened of all biodiversity hotspots, many plant and animal species have already started to shift their distributions to higher elevations in response to warming. However, a variety of biotic and abiotic factors may stabilize Andean timberlines and halt further upslope migrations into the high elevation grasslands (referred to as “puna” in southern Peru) above the forest. One possibility is that small forest patches that occur above-timberline throughout the Andes may facilitate forest expansion into newly suitable areas in the puna, yet little is known about the ecology or function of these patches. In this study, we examined seedling recruitment patterns, seed dispersal, and microclimate at the timberline, in and around above-timberline forest patches, and in the puna. The above-timberline forest patches had similar patterns of seed dispersal as the timberline but overal <1% of captured seeds were dispersed 10m into the puna. At both the patch edges and the forest timberline, seedling abundances were lower in the puna relative to the adjacent forest and forest–puna ecotone. This reduction may be a result of reduced seed dispersal across the forest–puna ecotone and/or decreased germination of dispersed seeds due to the harsh microclimatic conditions occurring in the puna (daily temperature fluctuations are greatly elevated in the puna relative to the forest and frost events are more frequent and severe). While increasing temperatures associated with climate change may ameliorate some of the severe climatic conditions occurring in the puna, it will not directly affect other potential recruitment limitations such as reduced seed dispersal, high levels of UV radiation, and anthropogenic activities (cattle grazing and fires) in the puna. With the reduction of anthropogenic activities, above-timberline forest patches may serve as nucleating foci for future forest expansion into the puna. However, our results indicate that any upslope migration of the timberline into the puna will likely occur at a rate that is slower than what is required to keep pace with warming because recruitment is restricted to a narrow strip along the forest–puna borders. Slowed forest expansion into the puna could act as a barrier to the upslope migration of Andean cloud forest species leading to extreme losses of Andean biodiversity.

A new species of Pristimantis (Anura: Strabomantidae) from Andean cloud forests of northern Peru

A new species of Pristimantis (Anura: Strabomantidae) from Andean cloud forests of northern Peru

Range size and climatic niche correlate with the vulnerability of epiphytes to human land use in the tropics

AbstractAimRange‐restricted species account for a large proportion of global biodiversity, and many such species are highly threatened by deforestation and intensifying land use in the tropics. The effects of land use on the diversity of range‐restricted species have rarely been studied and remain unknown for vascular epiphytes – diverse and important elements of tropical forests. This study analyses the vulnerability of range‐restricted epiphyte species to human land use, compared to that of widespread species.LocationWestern Ecuador (Chocó ecoregion): lowland rain forest (Bilsa, 0°21′ N 79°44′ W, 450–650 m a.s.l.) and Andean cloud forest (Otonga, 0°25′ S 79°01′ W, 1650–2250 m a.s.l.).MethodsThe epiphytic vegetation of 220 study plots was surveyed. Distribution data based on herbarium specimens were compiled for all identified species in order to estimate their geographical and elevational ranges as well as the climatic conditions within the species' ranges. These range characteristics were compared for species found in contiguous primary forests, primary forest fragments, secondary forests, and for isolated remnant trees in pastures.ResultsOf the 587 identified epiphyte species, 252 were endemic to the Chocó ecoregion (42.9%). Chocó endemics were not more strongly affected by human land use than non‐endemics. However, small geographical ranges and narrow climatic niches were associated with higher vulnerability to habitat changes caused by land use. Epiphyte assemblages in young secondary forests had the lowest proportions of range‐restricted species and were dominated by species with broad elevational ranges. Species in secondary forests occupied the broadest ranges of mean annual temperature and precipitation; species on isolated remnant trees at the lowland site inhabited on average warmer and drier geographical ranges than species in the primary forest.Main conclusionsEpiphyte species with restricted geographical distributions and narrow climatic tolerances are particularly vulnerable to human‐induced habitat changes, but endemism to national or biogeographical entities alone is a poor indicator of vulnerability. Instead, narrower ecological niches correlate with lower plasticity towards changes in microclimatic habitat conditions. Besides a higher extinction risk due to their small range sizes, many range‐restricted species might be threatened by their lower tolerance to the impacts of human land use.

Anthropogenic control of late-Holocene landscapes in the Cuzco region, Peru

The rise of complex Andean cultures is tied to increasingly sophisticated use of natural resources and infrastructural development. Considerable debate surrounds the extent to which these societies were forced to respond to changing climates or whether their modifications to the landscape minimized climate impacts. Here, we present a region-wide perspective of paleoecological changes around Cuzco, Peru using three lake sediment records. We investigate whether vegetation shifts in the three records occurred simultaneously, and explore whether such changes were due to climatic conditions or human activities, or both. A new paleoecological record from Lake Huaypo reveals a transition from Amaranthaceae (i.e. quinoa) cultivars to maize at c. 2800 cal. yr BP. This agricultural change is also documented at two other Andean lakes: Marcacocha (Chepstow-Lusty A (2011) Agro-pastoralism and social change in the Cuzco heartland of Peru: A brief history using environmental proxies. Antiquity 85: 570–582) and Pacucha (Valencia BG, Urrego DH, Silman MR et al. (2010) From ice age to modern: A record of landscape change in an Andean cloud forest. Journal of Biogeography 37: 1637–1647). Wetter climatic conditions are inferred to be a leading cause behind the change from Amaranthaceae to maize cultivation. At 1300 cal. yr BP, a rapid increase in Andean forest pollen types, especially Alnus, is observed at Huaypo, with similar changes occurring at Marcacocha at c. 1000 cal. yr BP and at Pacucha at c. 500 cal. yr BP. Drier paleoclimatic conditions at the time and the importance of Alnus, a species well-known for its ability to grow quickly and its widespread use for fuel and timber, suggest that the expansion was due partly to agroforestry. The Huaypo paleoecological record reveals that the practice of agroforestry first began during the Wari Period, and then continued through the Late Intermediate Period and period of Incan rule.

A new species of Pristimantis (Anura: Strabomantidae) from Andean cloud forests of northern Peru

We describe a new species of Pristimantis from cloud forests of the eastern versant of the Andes in northern Peru. Thetype locality lies in Quebrada del Vino, Provincia San Ignacio, Departamento Cajamarca, Peru. The new species is mostsimilar to P. crucifer, P. eriphus, P. flavobracatus, P. leucorrhinus, P. lucasi, and P. vilcabambae, with which it shares thepresence of large conical eyelid tubercles, ulnar tubercles, and heel and tarsal tubercles as well as flash colours on the groinsurrounded by bold black stripes and white stripes. The new species can nonetheless be distinguished from all of them by,having tympanic membrane and annulus, by males having nuptial pads and vocal slits, and by having finger discs scarcely enlarged and truncated with ungual flap not indented.

Leaf Spectra and Weight of Species in Canopy, Subcanopy, and Understory Layers in a Venezuelan Andean Cloud Forest

We characterize the leaf spectra of tree species of an Andean cloud forest in Venezuela, grouped according to position in canopy, subcanopy and understory. We measured leaf reflectance and transmittance spectra in the 400–750 nm range using a high-resolution spectrometer. Both signals were subtracted from unity to calculate the absorbance signal. Nine spectral variables were calculated for each signal, three based on wide-bands and six based on features. We measured leaf mass per unit area of all species, and calculated efficiency of absorbance, as ratio of absorbance in photosynthetic range over leaf mass. Differences among groups were significant for several absorbance and transmittance variables, leaf mass, and efficiency of absorbance. The clearest differences are between canopy and understory species. There is strong correlation for at least one pair of band variables for each signal, and each band variable is strongly correlated with at least one feature variable for most signals. High canonical correlations are obtained between pairs of the three canonical axes for bands and the first three canonical axes for features. Absorbance variables produce species clusters having the closest correspondence to the species groups. Linear discriminant analysis shows that species groups can be sorted by all signals, particularly absorbance.

Diversity of Prominent Moths (Lepidoptera: Noctuoidea: Notodontidae) in the Cloud Forests of Northeastern Ecuador, with Descriptions of 27 New Species

AbstractThe prominent moth fauna (Lepidoptera: Notodontidae) of Yanayacu Biological Station (Napo Province) in northeastern Ecuador was surveyed to assess which species at the site had been previously described and which were new to science. Taxonomic studies based on comparisons with type material revealed that, of the 67 Notodontidae recorded at Yanayacu, 54% were undescribed before 2009. In this article, 27 species belonging to 12 different genera in four subfamilies are newly described. These findings emphasize the remarkable levels of undocumented insect diversity found in Andean cloud forests, adding further strength to the argument that conservation efforts should focus on preserving such habitats.

Distribution extension of Strabomantis ruizi (Lynch, 1981) (Amphibia, Anura, Strabomantidae) from the department of Valle del Cauca, Colombia

Strabomatis ruizi is a large-sized frog from the Andean cloud forest of Cordillera Occidental, department of Valle del Cauca, Colombia. We present two new records for Strabomantis ruizi on the eastern slope of Cordillera Occidental,Valle del Cauca, Colombia.

Effect of Host Tree Traits on Epiphyte Diversity in Natural and Anthropogenic Habitats in Ecuador

ABSTRACTVascular epiphytes represent a highly diverse element of tropical rain forests, but they depend strongly on the structure and taxonomic composition of their tree communities. For conservation planning, it is therefore critical to understand the effect of host tree characteristics on epiphyte species richness in natural and anthropogenically transformed vegetation. Our study compares the effect of human land‐use on epiphyte diversity based on 220 study plots in a lowland rain forest and an Andean cloud forest in western Ecuador. We evaluate the relevance of host tree size and taxonomic identity for epiphyte species richness in contiguous primary forests, forest fragments, isolated remnant trees (IRTs), and secondary forests. At both study sites, epiphyte diversity was highest in primary forests, and it was lowest on IRTs and in secondary forests. Epiphyte species numbers of forest fragments were significantly reduced compared with the contiguous primary forest at the lowland study site, but not in the cloud forest area. Host tree size was a core predictor among secondary forests, but it had less significance within other habitat types. Taxonomic identity of the host trees also explained up to 61 percent of the variation in epiphyte diversity, especially for IRTs. The structural and taxonomic composition of the tree community in anthropogenically transformed habitat types proved to be fundamental to epiphyte diversity. This highlights the importance of deliberate selection of tree species for reforestation in conservation programs and the possible negative effects of selective logging in primary forests.Abstract in Spanish is available at http://www.blackwell‐synergy.com/loi/btp.

How anthropogenic disturbances affect the resilience of a keystone palm tree in the threatened Andean cloud forest?

To conserve tropical forests, it is crucial to characterise the disturbance threshold beyond which populations of tropical trees are no longer resilient. This approach is still not widely employed, especially with respect to the effects of moderate disturbances. Compensation effects, such as positive interactions among plants, are addressed even more rarely. We attempt to identify the extents to which the distribution of the keystone palm tree Ceroxylon echinulatum is regulated by various regimes of deforestation in a threatened tropical montane cloud forest in the North-West Andes of Ecuador. The demographic structure of this palm tree was examined in three habitats: old-growth forest, forest disturbed by selective logging, and deforested pasture. Patterns were related to stand structure, microclimate, and soil composition. Seedling desiccation owing to severe aboveground water stress led to the absence of juvenile palms in pastures, and thus was predictive of a near extinction of the species in this habitat. However, shade provided by dominant bunchgrass in pastures considerably reduced above- and belowground water stress by diminishing light intensity. Selective logging resulted in a higher density of individuals in disturbed forests than in old-growth forests, but was associated with a spoiled spatial structure. Therefore, the protection of residual old-growth forests is a prerequisite for the conservation of C. echinulatum, although secondary forests might act as provisional refuges that promote its resilience. The reduction of water stress by nurse grasses in pastures represents a promising approach to promote the resilience of tropical tree species and their associated communities after deforestation.

From ice age to modern: a record of landscape change in an Andean cloud forest

AbstractAim To investigate the palaeoecological changes associated with the last ice age, subsequent deglaciation and human occupation of the central Andes.Location Lake Pacucha, Peruvian Andes (13°36′26″ S, 73°19′42″ W; 3095 m elevation).Methods Vegetation assemblages were reconstructed for the last 24 cal. kyr bp (thousand calibrated 14C years before present), based on pollen analysis of sediments from Lake Pacucha. An age model was established using 14C accelerator mass spectrometry dates on bulk sediment. Fossil pollen and sedimentological analyses followed standard methodologies.Results Puna brava replaced the Andean forest at the elevation of Lake Pacucha at the Last Glacial Maximum (LGM). Deglaciation proceeded rapidly after 16 cal. kyr bp, and near‐modern vegetation was established by c. 14 cal. kyr bp. The deglacial was marked by the range expansion of forest taxa as grassland taxa receded in importance. The mid‐Holocene was marked by a lowered lake level but relatively unchanged vegetation. Quinoa and maize pollen were found in the latter half of the Holocene.Main conclusions Temperatures were about 7–8 °C colder than present at this site during the LGM. The pattern of vegetation change was suggestive of microrefugial expansion rather than simple upslope migration. The mid‐Holocene droughts were interrupted by rainfall events sufficiently frequent to allow vegetation to survive largely unchanged, despite lowering of the lake level. Human activity at the lake included a 5500‐year history of quinoa cultivation and 3000 years of maize cultivation.

Insensitive blueberries: a total-evidence analysis of Disterigma s.l. (Ericaceae) exploring transformation costs.

Disterigma sensu lato (s.l.) is a polyphyletic genus of neotropical blueberries that comprises 37 species found in Central and South America, mostly in Andean cloud forests and páramos. The present phylogenetic analysis, based on molecular and morphological data for 84% of the species of Disterigma s.l., addressed the monophyly of the genus and identified the putative morphological synapomorphies of the main clades. The sensitivity of the phylogenetic hypotheses to the choice of analytical parameters was addressed in detail, by varying all possible parameters and applying different treatments for indel coding. A total of 29 transformation cost matrices were investigated and all these analyses were performed in POY 4, using direct optimization. A diagnosable Disterigma sensu stricto (s.s.) clade was recovered in all analyses, despite changes in the transformation costs. Additionally, none of the analyses refuted the segregation of D.trimerum, D.ulei, D.pentandrum, D.rimbachii, and D.bracteatum from Disterigma s.s. Although measurements of congruence are used to choose among alternative analytical parameter sets, the behaviour of the RILD index (rescaled incongruence length difference) in this study suggested that it may not be a good measure of congruence and that further studies are necessary to better understand its performance. © The Willi Hennig Society 2009.

The influence of parental behavior on vulnerability to nest predation in tropical thrushes of an Andean cloud forest

The Skutch hypothesis predicts that parental activity around the nest may attract the attention of predators and thus, in the tropics where predation pressure may be high, selection favors reduced parental activity. This hypothesis has been questioned by studies demonstrating that parents can decrease the risk of nest predation through nest defense. The link between parental activity and predation risk may be further confounded by nest site characteristics. We examined the effects of parental behavior and nest site on clutch survival in two sympatric tropical thrushes (Myadestes ralloides and Turdus leucops). We compared survival rates of clutches in three treatments: 1) natural nests at the incubation stage, 2) unattended nests (un‐manipulated nests of the same species, with clutches unattended by parents), and 3) exposed clutches (eggs exposed in unconcealed positions, unprotected by the nest). Parental activity had a positive effect on clutch survival, which was revealed by significantly higher survival rate of clutches in attended nests compared to unattended nests. The effect of nest site was less clear: clutches in unattended natural nests survived better than clutches in exposed sites selected by humans, but results were insignificant. We propose that parent birds can exclude a group of opportunistic predators, that are able to destroy unattended clutches. Nest site characteristics may be less important in determining clutch survival in the tropics, where predator guilds are more diverse, making completely safe sites difficult to find. Our results challenge Skutch's hypothesis and point to the need for more data from tropical latitudes.

Edge Effects on Richness, Abundance and Diversity of Frogs in Andean Cloud Forest Fragments

Abstract To understand the influence of edge effects on an anuran community within two fragments of different size in an Andean cloud forest, anuran richness, abundance and diversity were studied on transects located at 2, 50, 100 and 200 m from the forest border to the interior. Measures of microhabitat and environmental variables in each sampling site were recorded. Borders with abrupt edges showed the lowest diversity, suggesting that the environmental variables registered demonstrate adverse conditions for the establishment of frogs. The use and the configuration of the adjacent matrix appears to have a strong influence on the edge effect as perceived by the anurans in this area, being much more pronounced across forest borders that abruptly neighbour cattle pasture.

New and Interesting Records ofCladoniaand their Lichenicolous Fungi from the Andean Cloud Forest in Bolivia

The paper deals with 18 species of the lichen genus Cladonia, including eight species new to Bolivia: C. cf. borbonica, C. coccifera, C. confragosa, C. dactylota, C. granulosa, C. kriegeri, C. merochlorophaea, and C. squamosa. Furthermore, C. kriegeri is recorded here from its second and third localities in the world. Also five lichenicolous fungi are reported; among them Arthrorhaphis aeruginosa, Polycoccum microcarpum and Sphaerellothecium cladoniae are new to the southern hemisphere, and Roselliniella cladoniae and Tremella cladoniae are new to Bolivia. Additionally, Polycoccum microcarpum is reported for the first time from Slovakia and Ukraine. Cladonia confragosa is reported as a new host for Sphaerellothecium cladoniae and Tremella cladoniae.

Diet, microhabitat and time of activity in a Pristimantis (Anura, Strabomantidae) assemblage

We tested if the richness and abundance of six closely related species of Pristimantis significantly varied among three transects located at different distances from a creek in an Andean cloud forest. We found that richness and abundance of frogs varied significantly among transects, being the transect located at the forest interior the richest in frog species and number of individuals. We chose these more crowded sites to evaluate resource use differences among the species. We evaluated ecological variables such as microhabitat, diet, and time of activity in these species that are similar in morphology and body size, to determine whether they have differences in the use of these resources. Most specimens perch on leaves at heights within 1.5 and 2.0 m of the ground and are nocturnal; only P. douglasi was found with diurnal and nocturnal activity. The species had similar diets, they ingested a wide spectrum of prey sizes that are similar among species, months, and between transects. Almost all collected frogs were juveniles and were found during every single month of sampling suggesting continuous reproduction; however, adults and juveniles of P. douglasi were absent during some of the drier months, indicating seasonality. Thus, we found that most of these Pristimantis species occupy the forest interior and that there is no a strong segregation in the use of the evaluated resources, only one species had a slight difference in activity and reproductive time.

A NOVEL NEST ARCHITECTURE WITHIN THE FURNARIIDAE: FIRST NESTS OF THE WHITE-BROWED SPINETAIL

Abstract The White-browed Spinetail (Hellmayrea gularis), of the Andean cloud forests, is the sole member of the genus Hellmayrea, and its phylogenetic relationships are still unresolved. The diversity of nest architectures in the family Furnariidae provides many phylogenetically informative characters; however, information on the nest of this enigmatic genus is lacking. Here, we describe four nests of Hellmayrea discovered in Ecuador. All nests were embedded within hanging masses of epiphytic moss, but were not pendulous, being supported from below or by stems incorporated in side walls. All nests were balls with a side entrance, externally built of green moss and internally of dry bamboo leaves. The bottom of the chamber was lined with Tillandsia seed down and, in one nest, tree-fern scales were also used. These first nests of Hellmayrea represent a type of nest architecture previously unknown in the family Furnariidae.