Northern Ecuadorian Andes Research Articles

Land use and land cover change in a tropical mountain landscape of northern Ecuador: Altitudinal patterns and driving forces

Tropical mountain ecosystems are threatened by land use pressures, compromising their capacity to provide ecosystem services. Although local patterns and interactions among anthropogenic and biophysical factors shape these socio-ecological systems, the analysis of landscape changes and their driving forces is often qualitative and sector oriented. Using the Driver-Pressure-State-Impact-Response (DPSIR) framework, we characterized land use land cover (LULC) dynamics using Markov chain probabilities by elevation and geographic settings and then integrated them with a variety of publicly available geospatial and temporal data into a Generalized Additive Model (GAM) to evaluate factors driving such landscape dynamics in a sensitive region of the northern Ecuadorian Andes. In previous agricultural land located at lower elevations to the east of the studied territory, we found a significant expansion of floriculture (13 times) and urban areas (25 times), reaching together almost 10% of the territory from 1990 to 2014. Our findings also revealed an unexpected trend of páramo stability (0.75-0.90), but also a 40% reduction of montane forests, with the lowest probability (<0.50) of persistence in the elevation band of 2800-3300 m; agricultural land is replacing this LULC classes at higher elevation. These trends highlight the increasing threat of permanently losing the already vulnerable native mountain biodiversity. GAMs of socio-economic factors, demographic, infrastructure variables, and environmental parameters explained between 21 to 42% of the variation of LULC transitions observed in the study region, where topographic factors was the main drivers of change. The conceptual and methodological approach of our findings demonstrate how dynamic patterns through space and time and their explanatory drivers can assist local authorities and decision makers to improve sustainable resource land management in vulnerable landscapes such as the tropical Andes in northern Ecuador.

Diversidad de comunidades fúngicas aisladas de tejidos sintomáticos de la uvilla (Physalis peruviana) en los Andes Ecuatorianos

We used microbial culture specific methods to assess the occurrence and diversity of fungal communities inhabiting symptomatic foliar tissue of Cape gooseberry (Physalis peruviana) at four different field plots in the northern Ecuadorian Andes. We categorized the isolated fungi based on their morphological characteristics and subsequently identified them through rDNA sequencing of the ITS region. We recovered 75 ascomycetous isolates which represented 13 genera, revealing a total of 20 taxa. We found most isolates recovered from necrotic and straw-colored tissues to belong to the genus Alternaria, while other fungal taxa frequently found were Epicoccum, Diaporthe, and Xylaria. To our knowledge, this is the first study to report the mycobiota associated to P. peruviana plants showing disease symptoms, from which we record 2 new genera of fungi for the first time in Ecuador. Our results are expected to provide useful information for future assessments of biological control on tropical commercial.

Diversidad de comunidades fúngicas aisladas de tejidos sintomáticos de la uvilla (Physalis peruviana) en los Andes Ecuatorianos

We used microbial culture specific methods to assess the occurrence and diversity of fungal communities inhabiting symptomatic foliar tissue of Cape gooseberry (Physalis peruviana) at four different field plots in the northern Ecuadorian Andes. We categorized the isolated fungi based on their morphological characteristics and subsequently identified them through rDNA sequencing of the ITS region. We recovered 75 ascomycetous isolates which represented 13 genera, revealing a total of 20 taxa. We found most isolates recovered from necrotic and straw-colored tissues to belong to the genus Alternaria, while other fungal taxa frequently found were Epicoccum, Diaporthe, and Xylaria. To our knowledge, this is the first study to report the mycobiota associated to P. peruviana plants showing disease symptoms, from which we record 2 new genera of fungi for the first time in Ecuador. Our results are expected to provide useful information for future assessments of biological control on tropical commercial.

Change, Collective Action, and Cultural Resilience in Páramo Management in Ecuador

This study examines how agricultural frontier expansion and grazing practices develop in the páramos under communal tenure in the northern Ecuadorian Andes and how rules to control them emerge within communal governance. We approach these questions through the lens of collective action and cultural resilience, to understand the evolution of communal governance. We analyze a case study of the Comité de Páramo Ñukanchik Urku, a multicommunal organization created in the 1990s for collective resource management. We use the analytical framework of social–ecological systems (SES) to approach changes of the agricultural frontiers and grazing activities as conservation outcomes resulting from changes in resource units, actors, and governance structures. Through a mixed-method approach combining air photo analysis (years 1956, 1993, and 2008) and qualitative research, we examine spatial patterns of settlement and agricultural frontier expansion, historical grazing practices, and the main elements of current collective páramo management. Our results indicate that: (1) the demarcation of an agreed agricultural frontier as a territorial landmark is a response aiming to control the increase of crops and dwellings at higher elevations, and to limit grazing activities; (2) the authority's legitimation of the Committee and its Board is crucial to develop rules and to enforce them; and (3) legitimation is achieved through conservation knowledge and autonomous decisions to control páramos considered a communal territory. A broader comprehension of the context and history of cultural change is needed to understand the emergence of communal governance of páramos. Cultural-political dimensions are key to the cultural resilience of social systems in SES and to strengthening rules and institutional diversity to manage the commons in Andean communities.

Two new Oxytrechus species from Ecuadorian páramo (Coleoptera, Carabidae, Trechinae).

Description and illustration of two new Oxytrechus species from the páramos of the northern Ecuadorian Andes. O. chioriae n. sp. is distributed at high altitude on the Chimborazo volcano on the Occidental Cordillera; O. cayambeensis n. sp. is located on the Oriental Cordillera and colonizes the Cayambe volcano. The two species are compared to other Ecuadorian species and some considerations about the distribution pattern of South-American species of Oxytrechus are proposed.

Mammalian carnivore occupancy is inversely related to presence of domestic dogs in the high Andes of Ecuador.

Although the Andes have long been occupied by people, habitat loss, fragmentation through deforestation, and other human activities such as introduction of invasive species have increased drastically during the past century. The Ecuadorian Andes are considered a biodiversity hotspot. However, the fauna and threats to the region are poorly studied, and understanding of factors that shape the distribution of species in habitats disturbed by human activities is needed to identify and mitigate region-wide threats to wildlife. We evaluated factors associated with patterns of occurrence of Andean carnivores in landscapes of the northern Ecuadorian Andes, particularly habitat loss, fragmentation, and occupancy of domestic dogs, and determined whether thresholds occurred for these factors beyond which carnivore occurrence declined markedly. Five study areas (each 20 x 20 km) were surveyed with a total effort of 2,800 camera trap nights. Occupancies of four of the eight carnivores known from the region were best predicted by occupancy of domestic dogs rather than measures of habitat loss and fragmentation [Andean fox (Pseudalopex culpaeus), puma (Puma concolor), striped hog-nosed skunk (Conepatus semistriatus), and Andean bear (Tremarctos ornatus)]. The two largest carnivores, puma and Andean bear, demonstrated significant threshold responses to the presence of domestic dogs at two sites. Four smaller carnivores were recorded too infrequently to model occupancy, and at least two of these species appear to be in decline. The magnitude of domestic dog impacts on native species in tropical areas like the Ecuadorian Andes currently are not recognized. Results of our study indicate that small and large carnivores are in urgent need of conservation and clearly point to dogs as a significant threat to a broad range of native species.

Three millennia of vegetation and environmental dynamics in the Lagunas de Mojanda region, northern Ecuador

AbstractThe pollen record from Lagunas de Mojanda, located at 3748 m a.s.l. (northern Ecuadorian Andes) reflects the vegetation and climate dynamics for the last ca 3400 cal yr BP. Páramo vegetation has been the main vegetation type since the beginning of the record. At Lagunas de Mojanda, from the last ca 3400 to 2200 cal yr BP, grass páramo was well represented mainly by Poaceae (40%) and the occurrence ofValeriana(5%), while montane forest taxa were poorly represented and subpáramo taxa were rare. The vegetation composition suggests cool and humid conditions. Between ca 2200 and ca 1300 cal yr BP, montane rainforest and subpáramo taxa had a higher presence but páramo taxa remained the main vegetation type in the study area, suggesting cool climatic conditions. From ca 1300 to ca 500 cal yr BP, páramo vegetation remained stable, with higher presence ofPhlegmariurusandIsoetes, suggesting cool and humid conditions. The last ca 500 cal yr BP generally show lower frequency of montane rainforest and subpáramo taxa. Páramo vegetation reached the highest share, with the presence of Poaceae,PlantagoandRanunculussuggesting a trend of peat bog drying. Fires were present during the whole record, perhaps human-caused, but the study area does not show great disturbance except from ca 1300 to 500 cal yr BP, a period of an evident higher influx of charcoal particles coincidentally with nearby ancient human occupation.

Altered activity patterns and reduced abundance of native mammals in sites with feral dogs in the high Andes

Negative impacts of some introduced carnivores like feral cats are well documented, widespread, and significant. Comparatively, the effects of feral dogs (individuals that are not associated with people or human settlements) on native wildlife are poorly known, even though feral dogs occur worldwide. We assessed the density of feral dogs and compared relative abundance, activity patterns and habitat use of 10 species of mammals in areas with and without feral dogs in Cayambe-Coca National Park in the northern Ecuadorian Andes using line transect surveys, camera traps, and track and sign surveys. In areas where feral dogs were present, four native mammals were absent: mountain coati (Nasuella olivacea), mountain paca (Cuniculus taczanowskii), long-tailed weasel (Mustela frenata), and northern pudu (Pudu mephistophiles). Relative abundances of six species were lower compared to areas without feral dogs: puma (Puma concolor), Andean fox (Lycalopex culpaeus), Andean bear (Tremarctos ornatus), striped hog-nosed skunk (Conepatus semistriatus), mountain tapir (Tapirus pinchaque), and little red brocket deer (Mazama rufina). Three species significantly altered activity patterns where feral dogs were present (Andean bear, mountain tapir, and little red brocket deer). In contrast, none of the native mammal species exhibited shifts in habitat use in areas with feral dogs. Dogs used all habitat types according to availability. Our results point to feral dogs as a significant problem for the native mammal community of this Andean region, and highlight the need to consider feral dogs as a potential threat to wildlife in other regions where anthropogenic effects appear to be low but feral dogs are present, particularly natural areas that contain endangered and endemic species.

Multiple trends in interspecific crop diversity: a longitudinal case study from the Ecuadorian Andes

This case study reports on recent developments in the extent of interspecific crop diversity in Cotacachi located in the Northern Ecuadorian Andes. Like in many other regions, trends of genetic erosion led to simplified fields with reduced levels of crop diversity in this area during the twentieth century. The present study examines whether, at the crop level, this reduction continued after the millennium shift. The problem is approached through a longitudinal comparison of crop richness on surveyed farms in 2003 and 2009. The results display multiple trends; while a few field crops remained stable in terms of their presence among farms, some increased and others decreased their role. Simultaneously, there was a marked increase in the planting of vegetables and fruits in home gardens. On a general level, these varied trends resulted in a significant rise in farms’ average crop richness amounting to five more crops, as well as an overall 42 % increase in the frequency with which any crop was planted among the farms. The observed trends are discussed in the light of local sociocultural, economic and agroclimatic changes.

A New Species ofAtractus(Serpentes: Dipsadidae) from the Andes of Ecuador

Abstract: A new species of Atractus is described from cloud forests of the extreme northern Ecuadorian Andes, Tulcan County, Carchi Province. Atractus savagei sp. nov. is distinguished from all congeners by the combination of 17 dorsal scale rows, long loreal, six supralabials (third and fourth contacting orbit), seven infralabials (first four contacting chinshields), 5–8 maxillary teeth, 161–165 ventrals in females and 149–154 in males, 23–26 subcaudals in females and 28–33 in males, a brown dorsum with black specks on the margins of scales, two black longitudinal stripes on each side of the body, yellow ventral color of head gradually changing to orange and red toward the back of the body, venter with lateral and median series of black blotches arranged in conspicuous longitudinal stripes, moderate body size, a long tail in males, and a moderately bilobed, barely capitate, and slightly calyculate hemipenis. Based on shared morphological characters, especially hemipenial features, we propose to tentativ...

Percepción de la participación de parteras y sanadores tradicionales andinos ecuatorianos en un programa de formación en salud

El enlace entre la visión sanitaria occidental y la medicina indígena cimienta la identidad colectiva en la formación en salud. Analizar la percepción de la participación en un programa de formación en salud, desde la visión de parteras y sanadores tradicionales de la zona norte andina ecuatoriana. Diseño cualitativo de tipo interpretativo/ explicativo, se realizaron 25 entrevistas a profundidad y tres grupos focales a 20 parteras y 5 sanadores tradicionales, autodefinidos indígenas; el muestreo fue intencionado y razonado, de tipo opinático. Las subcategorías fueron definición de la participación en un programa de formación en salud, rol social y formación en salud y aplicación de la formación. El contraste de la narrativa se analizó a partir del sexo y tipología del informante. La participación en un programa de formación en salud fue descrita como la oportunidad para compartir, recuperar, conservar y fortalecer la medicina tradicional; opinar en cuestiones de salud-enfermedad en escenarios públicos como asambleas, y en escenarios privados como el acto de curar a la gente. La construcción de la participación en un programa de formación en salud, desde los actores de medicina tradicional enriquece el proceso.

Spatiotemporal dynamics of a páramo ecosystem in the northern Ecuadorian Andes 1988–2007

Paramo is a term used to describe tropical alpine vegetation between the continuous timberline and the snow line in the Northern Andes. Paramo environments provide important species habitat and ecosystem services. Changes in spatial extent of the paramo ecosystem at Pambamarca in the Central Cordillera of the northern Ecuadorian Andes were analysed using multi-temporal Landsat TM/ETM+ satellite data. The region suffered a loss of 1826.6 ha or 20% of the total area at a rate of 100 ha/annum during 1988-2007 period. It is found that permanent paramo cover decreased from 8350 ha in 1988 to 5864 ha in 2007 at a fairly constant rate (R²=0.94). This loss is attributed to expansion of commercial agriculture and floriculture in the valleys coupled with increased population pressure. Land at higher elevations has been cleared for small scale agriculture. Loss of the paramo ecosystem will exert a number of negative impacts on ecosystem services and livelihoods of the local population at Pambamarca.

Reconstruction of late Holocene forest dynamics in northern Ecuador from biomarkers and pollen in soil cores

Centuries of human interference have led to large scale reduction of montane forests in the northern Ecuadorian Andes. As a result the natural position of the upper forest line (UFL) in the area is now subject of scientific debate, which is hindering sustainable reforestation efforts. Uncertainty is fuelled by insufficient precision of fossil pollen spectra to reconstruct the natural UFL position. Here we tried to resolve this issue by using biomarkers, i.e. plant species specific patterns of n-alkanes and n-alcohols, preserved in soils in the northern Ecuadorian Andes as additional proxy to reconstruct the natural UFL position. To unravel preserved biomarker patterns we used the recently developed VERHIB model, and for the first time assessed its applicability in soil archives. Changes in Holocene biomarker-based vegetation composition were directly compared to changes in pollen-based vegetation composition from the same soil profiles. Both proxies proved to be complementary and a combined application allowed for a more accurate reconstruction of past vegetation than with pollen analysis alone. We found that the present-day UFL in the study area has not been significantly depressed by human interference and was at 3650m maximally during late Holocene times. For the moment of post-glacial forest development we found a migration lag between pollen (earlier) and biomarkers (later). This reflects the difference between the non-transported biomarker signal showing spot-dating (thus in paleoecological studies functionally equalling the information from plant macro-remains in peat bogs), and the upslope wind-blown pollen signal showing an upslope forest expansion up to over a millennium ahead. The combined pollen-biomarker approach in soil cores shows great potential for vegetation reconstruction. However, more research of biomarker consistency and preservation is needed before application in other environments.

The influence of bioturbation on the vertical distribution of soil organic matter in volcanic ash soils: a case study in northern Ecuador

SummarySoil faunal bioturbation (‘bioturbation’) is often cited as a major process influencing the vertical distribution of soil organic matter (SOM). The influence of bioturbation on vertical SOM transport is complex because it is the result of interaction between different groups of soil faunal species that redistribute SOM through the soil profile in distinct ways. We performed a semi‐quantitative micromorphological analysis of soil faunal pedofeatures and related their occurrence to the vertical distribution of SOM and high‐resolution radiocarbon dating in volcanic ash soils under montane forest and grassland (páramo) vegetation in the northern Ecuadorian Andes. The páramo soil data suggest that bioturbation was largely responsible for the vertical distribution of SOM, while illuviation and root input were of minor importance. Bioturbation was caused by endogeic species, which typically mix the soil only over short vertical distances. Short vertical distance mixing was apparently enhanced by the upward shifting of bioturbation as a result of soil thickening due to SOM accumulation. A change from páramo to forest vegetation was accompanied by a change from endogeic to epigeic species. As these latter species do not redistribute material vertically, this eventually resulted in the formation of thick ectorganic horizons in the forest.

Methyl ketones in high altitude Ecuadorian Andosols confirm excellent conservation of plant-specific n-alkane patterns

To reconstruct past shifts in the upper forest line (UFL) in the Northern Ecuadorian Andes we are studying the applicability of plant-specific patterns of lipids preserved in soils as proxies for past vegetation along an altitudinal transect. Longer chain length n-alkanes, (C19–C35) were previously found to occur in plant-specific patterns in the dominant vegetation in the area as well as in preliminary soil samples, and may serve as such a proxy. In the present study, we assessed the preservation of n-alkane patterns with depth in soils from five excavations along an altitudinal transect 3500–3860m above sea level (m.a.s.l) in the area. We used the carbon preference index (CPI) as well as chain length distributions of n-alkanes and their most likely degradation products, n-methyl (Me) ketones, n-alcohols and n-fatty acids. Clear n-alkane patterns were found in all the soils and at all depths, while a clear relationship with the observed patterns of n-Me ketones identified them as the primary degradation product of the former. Very low average n-Me ketone/n-alkane ratio values were found, ranging from 0.03 to 0.15 at the top of the mineral soil, to 0.05–0.20 at the interface with an underlying palaeosol several thousand years old. The concurrent high CPI values indicate very limited degradation of n-alkanes with depth. Except for C33, the shifts in n-Me ketone/n-alkane values were similar for all chain lengths investigated, signifying an absence of preferential degradation of individual n-alkanes. With one exception, all the soils showed a similar increase in n-Me ketone/n-alkane values with depth, indicating that the degradation rates were not influenced by altitude. This means that, even if the total concentration of n-alkanes decreases over time, the characteristic pattern remains intact, conserving their potential as a biomarker for past vegetation reconstruction in the area, as well as for investigation of degradation processes of soil organic carbon.

The Holocene treeline in the northern Andes (Ecuador): First evidence from soil charcoal

Indications for the speed and timing of past altitudinal treeline shifts are often contradictory. Partly, this may be due to interpretation difficulties of pollen records, which are generally regional rather than local proxies. We used pedoanthracology, the identification and dating of macroscopic soil charcoal, to study vegetation history around the treeline in the northern Ecuadorian Andes. Pedoanthracology offers a complementary method to pollen-based vegetation reconstructions by providing records with high spatial detail on a local scale. The modern vegetation is tussock grass páramo (tropical alpine vegetation) and upper montane cloud forest, and the treeline is located at ca. 3600 m. Charcoal was collected from soils in the páramo (at 3890 and 3810 m) and in the forest (at 3540 m), and represents a sequence for the entire Holocene. The presence of páramo taxa throughout all three soil profiles, especially in combination with the absence of forest taxa, shows that the treeline in the study area has moved up to its present position only late in the Holocene (after ca. 5850 cal years BP). The treeline may have been situated between 3600 m and 3800 m at some time after ca. 4900 cal years BP, or it may never have been higher than it is today. The presence of charcoal throughout the profiles also shows that fires have occurred in this area at least since the beginning of the Holocene. These results contradict interpretations of palaeological data from Colombia, which suggest a rapid treeline rise at the Pleistocene–Holocene transition. They also contradict the hypothesis that man-made fires have destroyed large extents of forest above the modern treeline. Instead, páramo fires have probably contributed to the slowness of treeline rise during the Holocene.

Can isoprenoids in leaves and roots of plants serve as biomarkers for past vegetation changes? A case study from the Ecuadorian Andes

Large-scale clear-cutting and burning caused the altitude of the natural upper forest line (UFL) in the Northern Ecuadorian Andes to decline to the point that its ‘natural’ position is now uncertain. To obtain a detailed reconstruction of the dynamics of the UFL over the last few thousand years, traditional proxies alone do not suffice. For instance, pollen analysis suffers from a low altitudinal resolution due to the large wind-blown component. In an attempt to find new, additional proxies to study past UFL dynamics in the Ecuadorian Andes, we investigated the occurrence of isoprenoids (diterpenes, phytosterols and pentacyclic triterpenoids) in the roots and leaves of 19 plant species responsible for the dominant biomass input in soil and peat records along altitudinal transects covering approximately 500 m above and below the current UFL in two locations in the Northern Ecuadorian Andes. Isoprenoids can serve as biomarker if they are uniquely present in a relevant plant species and preserved well enough in chronological order in suitable records. Such biomarkers could help establish past vegetation dynamics including the UFL position. For an isoprenoid to be a biomarker in soils normally it must be absent from the roots of a plant species as roots do not enter soils in chronological order. For peat deposits this criteria only needs to be met for the peat species themselves as only roots from peat species will be present. Two diterpenes, four phytosterols and six pentacyclic triterpenoids met the criteria for biomarker in peat records. Of these, one diterpene, two phytosterols and three pentacyclic triterpenoids also met the criteria for biomarker in soils. Samples from a soil under forest, a soil under the adjacent paramo and a nearby peat deposit, 14C dated at approximately 1500 cal. AD and 200 cal. AD, were tested for the presence of isoprenoids that meet the criteria for biomarker. Such isoprenoids were only found in the peat bog samples. However, we found that changes of number and concentrations of isoprenoids with depth might provide additional information related to past vegetation changes. In conclusion, isoprenoids show potential for use in a multi-proxy approach to reconstruct past UFL locations in the Northern Ecuadorian Andes and other ecosystems with similar vegetation and soils.

Three new andean species of Drosophila (Diptera, Drosophilidae) of the mesophragmatica group

Three new species of mesophragmatica group, Drosophila amaguana, Drosophila shyri and Drosophila ruminahuii from Pasochoa Forest Reserve, northern Ecuadorian Andes, are described. The two subgroups currently composing the mesophragmatica group are renamed as the mesophragmatica subgroup to which the first two species have been added, and the viracochi subgroup to which the latter species has been added. These subgroups are defined based on the direction of the basal scutellar setae, which are divergent in the species of the former subgroup and convergent in the latter.

Do the Billecocha normal faults (Ecuador) reveal extension due to lithospheric body forces in the northern Andes?

Active compressional and transcurrent structures are widely reported for the entire northern Andes, whereas there is no clear evidence of extensional tectonics in that region. In contrast, both active compressional and extensional structures occur extensively in the Central Andes. Extensional tectonism in the central Andes occurs mainly in high plateaus of large wavelength (≥ 100 km), and is interpreted to have resulted from the effect of compensated high topography at the lithospheric scale. The observation of Holocene normal faults on the low wavelength (≤ 15 km) Billecocha high plateau in the northern Ecuadorian Andes raises a problem. Could the lithospheric body forces be the cause of the normal faulting in a chain with a mean altitude of ≤ 2800 m? Compared to the central Andes, where normal faulting is widely distributed across the chain, normal faulting on the Billecocha plateau is concentrated in a restricted 4-km-wide zone. In addition, normal faulting does not extend further than a few kilometres eastward, where compressive structures have been observed. Considering the local character of the extension, body forces at the lithospheric scale cannot be responsible for this normal faulting, and thus we can preclude a significant lowering of the magnitude of σH max in the northern Andes with respect to the central Andes. Analysis of these normal faults shows that normal faulting occurred between 10,000 yr and 6000 yr B.P. In addition, the relationship between the geometrical parameters (vertical throw and rupture length) of the major normal fault differs significantly from that given empirically by methods based on scale laws. In such a case, the Billecocha normal faults are unlikely to have a tectonic origin. Various local processes (e.g., gravity gliding, “sackung”) that may be possible are contemplated for triggering the normal faulting. In addition, a theoretical simple 2-D model is proposed in where local conditions peculiar to the plateau (structure, glaciation) and the surrounding areas are taken into account. In this model, normal faulting occurs by shearing along the planes of weakness (bedding planes) in response to the elastic rebound of the fluid-saturated plateau, which prevailed after the last glaciation.