Low temperature resistance in saplings and ramets of Polylepis sericea in the Venezuelan Andes

The frequent occurrence of all year-round below zero temperatures in tropical high mountains constitutes a most stressful climatic factor that plants have to confront. Polylepis forests are found well above the continuous forest line and are distributed throughout the Andean range. These trees require particular traits to overcome functional limitations imposed on them at such altitudes. Considering seedling and sapling stages as filter phases in stressful environments, some functional aspects of the regeneration of Polylepis sericea, a species associated to rock outcrops in the Venezuelan Andes, were studied. We characterized microclimatic conditions within a forest, in a forest gap and surrounding open páramo and determined low temperature resistance mechanisms in seedlings, saplings and ramets. Conditions in the forest understory were more stable compared to the forest gaps and open surrounding páramo. Minimum temperatures close to the ground were 3.6 °C lower in the open páramo compared to the forest understory. Maximum temperatures were 9.0 °C higher in the open páramo. Ice nucleation and injury temperatures occurred between ?6 and ?8 °C for both ramets and saplings, an evidence of frost avoidance to low nighttime temperatures. In this particular forest, this resistance ability is determinant in their island-like distribution in very specific less severe temperature habitats.     

Modelling the effect of temperature changes on plant life-form distribution across a treeline ecotone in the tropical Andes

ABSTRACT

Background: Classifying species from the high tropical Andes into plant life forms (PLF) can provide a more functional understanding of tropical treeline dynamics. However, little is known about the potential response of PLFs to climate warming.

Aims: The objective of this work was to evaluate the response of PLFs to environmental conditions above the upper montane forest in the Venezuelan Andes and forecast their potential distribution under warming scenarios using habitat suitability models.

Methods: We classified species into nine PLFs, analysed their current distribution using CCA and non-linear multiple regressions and forecasted their potential distribution under warming scenarios. We used anatomical leaf traits for shrubs and caulescent rosettes to refine their potential responses to climate.

Results: Tree cover sharply decreased with increasing elevation, while shrub and caulescent rosette distribution differed depending on their leaf traits. Projections suggested an upslope shift of all PLFs with warming and an increase in tree cover.

Conclusions: The analysis of the distribution of PLFs, by linking plant adaptive strategies to topography/climate, allowed projecting changes in vegetation physiognomy in response to warming. Projections of a moderate increase in tree cover in the grassland páramo did not indicate the formation of closed forests above the forest line.     

Ecophysiology and genetic diversity in species of the bamboo Chusquea in the high Andes,Venezuela

ABSTRACT

Background: Woody bamboos of the genus Chusquea grow along a broad range of elevations in the Venezuelan Andes. Their growth-form and density vary along the cloud forest – páramo gradient. In this article, we related ecophysiological traits and population genetic diversity information to explain the distribution of growth-form patterns of Chusquea in the Merida Andes, Venezuela.

Aims: We quantified differences in the ecophysiological response and genetic diversity of scandent cloud forest and shrub-like páramo bamboos of the genus Chusquea, taking in account the differences in their flowering patterns, growth-form and habitat.

Methods: We related low temperature resistance, water relations and leaf gas exchange variables to the growth-form, habitat, flowering patterns and genetic diversity in species of Chusquea. The genetic diversity study was based on Inter Sequence Simple Repeats and Random Amplified Polymorphic DNA markers analysis of cloud forest and páramo populations.

Results: Scandent cloud forest and shrub-like páramo species of Chusquea had a very similar ecophysiological response for all the variables analysed during wet and dry seasons and were capable of enduring freezing temperatures through moderate supercooling. Species associated with the cloud forest – páramo gradient maintained low stomatal conductance and transpiration rates that favoured high leaf water potentials, without limiting photosynthetic rates. Shrub-like bamboos growing above the continuous forest line had a small decline in net photosynthesis rates, associated with an increase in water use efficiency. Both scandent and shrub-like bamboos had a remarkably high genetic diversity, comparable to non-clonal species.

Conclusions: Species of Chusquea in the Venezuelan Andes are a physiologically relatively homogeneous group across a broad elevation gradient. Population genetic diversity appears to be more related with their flowering pattern and habitat conditions than with their growth form.     

High solar radiation hinders tree regeneration above the alpine treeline in northern Ecuador

Many tropical alpine treelines lie below their climatic potential, because of natural or anthropogenic causes. Forest extension above the treeline depends on the ability of trees to establish in the alpine environment. This ability may be limited by different factors, such as low temperatures, excess solar radiation, competition, soil properties, dispersal ability, and fires. In this paper we address the following two questions: Do trees regenerate above the present treeline, and what are the inhibiting factors for tree establishment? To answer these questions we described the spatial pattern of recent tree establishment below and above the present treeline in northern Ecuador. Also, we experimentally transplanted seedlings into the alpine vegetation (páramo) and the forest, and investigated the effect of shade, neighboring plants, and substrate on their survival. The number of naturally occurring tree sprouts (seedlings, saplings and ramets) was highest just outside the forest, and decreased with distance to the forest edge. However, only two species that were radiation-tolerant made up these high numbers, while other species were rare or absent in the páramo. In the forest, the species diversity of sprouts was high and the abundance per species was relatively low. The transplanted seedlings survived least in experimental plots without artificial shade where neighboring plants were removed. Seedling survival was highest in artificially shaded plots and in the forest. This shade-dependence of most tree species can strongly slow down forest expansion toward the potential climatic treeline. Due to the presence of radiation-tolerant species, the complete lack of forest expansion probably needs to be ascribed to fire. However, our results show that natural processes can also explain both the low position and the abruptness of tropical treelines.     

Plant functional diversity in tropical Andean páramos

ABSTRACT

Background: Tropical high mountains present extreme daily temperature variations, frequent high air evaporative demands and seasonal differences in soil water availability. Plants have adapted to these conditions through different avoidance-tolerance mechanisms. This review focuses on plant-growth forms and their adaptive strategies.

Aims: This integrated review of páramo plant traits aims at contributing to understanding the functioning of plant-growth forms and their significance on ecosystem properties under environmental climate and land-use changes.

Methods: Plant responses are presented along avoidance-tolerance gradients considering three main aspects: freezing resistance, water relations and gas exchange characteristics. Results from 45 herbaceous and 42 woody species along elevational gradients in the Venezuelan high Andes were analysed.

Results: Leaf supercooling is the common avoidance response of woody plants to night-time freezing temperatures, while herbaceous plants tolerate frost. Trees and caulescent rosettes maintain more positive leaf water potentials under water deficit conditions compared to more tolerant herbaceous species. All plant growth-forms showed strong stomatal control under dry-season conditions.

Conclusions: Páramo plant growth-forms may be separated according to an avoidance-tolerance gradient in response to water deficit and low temperature resistance. Woody growth-forms tend to avoid both freezing and water stress, while herbaceous forms tolerate frost and resist an unfavourable water status. Grasses and cushion plants are at the tolerant extreme of the gradient and coincide in that both reach the highest elevations in the páramo. Andean giant rosettes are freezing avoidant, particularly susceptible to water deficit and the most vulnerable, of all growth-forms, to changing environmental conditions.     

Phenological patterns and pollination network structure in a Venezuelan páramo: a community-scale perspective on plant-animal interactions

ABSTRACT

Background: Little information is available about life history of páramo plants such as phenology and plant-animal interactions.

Aims: We analysed phenological patterns of flowering and characterised the structure of a plant-pollinator network in a Venezuelan páramo in order to identify key species in this ecosystem.

Methods: We counted the number of individuals with flowers of 76 native plant species and recorded their pollinators in 16 permanent plots between 3000 and 4200 m monthly for three years. We used this dataset to develop a plant-pollinator network, on which nine different metrics related to structural properties were calculated.

Results: The flowering of most species concentrated during the rainy season (between May and November), however some species have continuous flowering. The guild of floral visitors included hummingbirds, flower piercers, bumblebees, Diptera and Lepidoptera. The plant – flower visitor interaction network did not exhibit nestedness, but showed a significant specialization index (H2) and high values of functional complementarity.

Conclusions: Páramo plants have the capacity of maintaining a resident nectarivorus fauna (bumblebees and hummingbirds) because of continuous flower offer during the year. However, the plant – pollinator network identified could be very sensitive to the loss component species, owing to high levels of specialisation and functional complementarity.     

Tropical and Temperate: Evolutionary History of Páramo Flora

Biogeography of the tropical alpine flora of South and Central America, the páramo flora, has been studied by dividing genera into tropical, temperate, and cosmopolitan chorological flora elements. Published molecular phylogenies of páramo genera are reviewed to summarize knowledge about evolutionary history of the páramo flora and to assess congruence between chorological and phylogenetic approaches. Molecular phylogenies suggest that both the tropical and temperate regions have been important source areas for evolution of the páramo flora. Conclusions derived from chorological patterns regarding origin of genera in páramo are mostly supported by phylogenetic data. Nevertheless, in Chuquiraga, Halenia, Huperzia, and Perezia the chorological scenario is rejected, and in Chusquea-Neurolepis, Elaphoglossum, Gunnera, Halenia, Jamesonia-Eriosorus, and Lasiocephalus independent colonization events from one or several source areas are suggested. Tropical and temperate genera contributed equally to modern species richness of the páramo flora. Among temperate genera, the northern hemisphere genera gave rise to more species in páramo than did genera from the southern hemisphere. So far, no unequivocal evidence has been provided for migration of páramo genera to the temperate zones.     

Ecological research in the tropical alpine ecosystems of the Venezuelan páramo: past,present and future

ABSTRACT

Background: Tropical mountain ecosystems of the Northern Andes have long fascinated researchers because of the unique conditions associated with cold climates in equatorial latitudes. More than six decades have elapsed since the beginning of systematic ecological research in the Venezuelan páramos, making them one of the best-studied tropical alpine regions in the world.

Aims: We review the conceptual development and state of the art of ecological research in the Venezuelan páramos, with emphasis on environmental and plant ecology research, presenting a general framework for the studies included in this special issue.

Methods: We provide a historical sketch of the periods that have marked ecological studies in the Venezuelan páramos. Then, we synthesise research on environmental drivers, plant population and community ecology, ecosystem functioning, the response of the páramo to climate change and human disturbance; we finally consider agroecology and conservation.

Results and conclusions: This review demonstrates the significant contributions made to alpine ecology in key areas such as biodiversity/ecosystem function changes during succession, nutrient cycling, species interactions and socio-ecological research. We indicate the need to develop a more integrated view of the links between evolutionary processes, functional diversity, community dynamics and ecosystem services both in natural and human-impacted areas.     

Phytogeography of the bryophyte floras of oak forests and páramo of the Cordillera de Talamanca, Costa Rica

Aim Central America is a biogeographically interesting area because of its location between the rich and very different biota of North and South America. We aim to assess phytogeographical patterns in the bryophyte floras of oak forests and páramo of the Cordillera de Talamanca, Costa Rica. Location Tropical America, in particular the montane area of Cordillera de Talamanca, Costa Rica. Methods The analysis is based on a new critical inventory of the montane bryophyte flora of Cordillera de Talamanca. All species were assigned to phytogeographical elements on the basis of their currently known distribution. Absolute and percentage similarities were employed to evaluate floristic affinities. Results A total of 401 species [191 hepatics (liverworts), one hornwort, 209 mosses] are recorded; of these, 251 species (128 hepatics, one hornwort, 122 mosses) occur in oak forests. Ninety‐three per cent of all oak forest species are tropical in distribution, the remaining 7% are temperate (4%) and cosmopolitan (3%) species. The neotropical element includes almost 74% of the species, the wide tropical element (pantropical, amphi‐atlantic, amphi‐pacific) only 19%. A significant part of the neotropical species from oak forests are species with tropical Andean‐centred ranges (27%). As compared with bryophyte species, vascular plant genera in the study region are represented by fewer neotropical, more temperate and more amphi‐pacific taxa. Bryophyte floras of different microhabitats within the oak forest and epiphytic bryophyte floras on Quercus copeyensis in primary, early secondary and late secondary oak forest show a similar phytogeographical make‐up to the total oak forest bryophyte flora. Comparison of oak forest and páramo reveals a greater affinity of the páramo bryophyte flora to temperate regions and the great importance of the páramo element in páramo. Surprisingly, oak forests have more Central American endemics than páramo. Main conclusions (1) Providing first insights into the phytogeographical patterns of the bryophyte flora of oak forests and páramo, we are able to confirm general phytogeographical trends recorded from vascular plant genera of the study area although the latter were more rich in temperate taxa. (2) Andean‐centred species are a conspicuous element in the bryophyte flora of Cordillera de Talamanca, reflecting the close historical connection between the montane bryophyte floras of Costa Rica and South America. (3) High percentages of Central American endemics in the bryophyte flora of the oak forests suggest the importance of climatic changes associated with Pleistocene glaciations for allopatric speciation.     

Stomatal response functions to environmental stress of dominant species in the tropical Andean páramo

ABSTRACT

Background: Stomatal response functions of dominant plant species can provide insights into the behaviour of ecosystems under environmental stress, and provide tools for modelling their response to climate change. However, they remain little studied in tropical Alpine ecosystems.

Aims: Our objective was to formulate and compare stomatal response functions for two dominant páramo species with different adaptive strategies to drought, the stress-tolerant shrub Hypericum laricifolium, and the stress avoiding giant rosette Espeletia schultzii and thus enable making projections as to their future fitness in a changing climate.

Methods: A reanalysis of data found in the literature and new ecophysiological and micrometeorological measurements were used to fit and test new stomatal response functions to environmental variables for these two species.

Results: The response functions of vapour pressure differences between leaf and air showed an exponential decrease for both species, while for photosynthetically active radiation (PAR), peak-form response functions provided the best fit. The response function for leaf water potential was linear for the drought-tolerant shrub and decreased exponentially for the stress avoiding giant rosette. Several thresholds prior to stomatal closure were also included in the functions.

Conclusions: Although stress-avoiding and stress-tolerant strategies are both successful in the Andean páramo, the response functions suggest that the tolerant shrub could be more resistant to more intense drought.     

Altitudinal distribution,diversity and endemicity of Carabidae (Coleoptera) in the páramos of Ecuadorian Andes

Species richness and diversity of Carabidae (Coleoptera), as well as rates of endemicity, are studied along altitudinal transects in the páramo of Ecuadorian Andes, from 3500 to 5000 m. Whereas a global tendency to reduction of species richness is evident from 4200 m upwards, two zones of high diversity and high proportion of endemic species occur at 3800–4000 m and at 4200–4400 m. Species turnover between grass páramo and superpáramo is significantly higher in drier mountains, especially in the Western Cordillera, than in humid mountains of the Eastern Cordillera. The altitudinal range of Carabid species tends globally to decrease along the vertical gradient, but with important local variations due to microenvironmental factors, especially humidity rate. When compared with recent phytogeographical studies, these results tend to support the idea that the majority of tussockgrass páramo is a secondary anthropogenic ecosystem. On the contrary, it is argued that the xeric landscape of the Chimborazo “arenal” is primordial, based on the presence of a stenotopic and possibly relict species, Pelmatellus andium Bates 1891.     

<Emphasis Type="Italic">Hypericum</Emphasis> species in the Páramos of Central and South America: a special focus upon <Emphasis Type="Italic">H. irazuense</Emphasis> Kuntze ex N. Robson

Knowledge about members of the flowering plant family Clusiaceae occurring in the tropical mountain regions of the world is limited, in part due to endemism and restricted distributions. High altitude vegetation habitats (Páramos) in Central and South America are home to numerous native Hypericum species. Information related to the phytochemistry of páramo Hypericum, as well as ecological factors with the potential to influence chemical defenses in these plants, is briefly reviewed. Results of the phytochemical analysis of Hypericum irazuense, a species collected in the páramo of the Cordillera de Talamanca in Costa Rica, are presented. Lastly, guidelines for the viable and sustainable collections of plant material, to facilitate future investigations of these interesting plants, are given.     

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.     

Ecohydrology of the Venezuelan páramo: water balance of a high Andean watershed

ABSTRACT

Background: The páramo provides key ecosystem services, including regulation and provision of water. To understand the underlying functions, an ecosystem approach is necessary.

Aims: We quantified the combined effect of vegetation and soils (integrated topographic and vegetation units – TVU) on the hydrological balance of a Venezuelan páramo micro-watershed and analyse its hydrological response to intra- and interannual rainfall variability.

Methods: Data (2008–2016) from meteorological stations of TVUs and of a streamflow station was used to calculate watershed level hydrologic balances. We quantified the impact of the TVUs outputs by calculating evapotranspiration under non-standard conditions (ETc adj).

Result: Evapotranspiration of wetlands and tarns was high, exceeding annual precipitation. Shrubland had low evapotranspiration. Recharge of páramo reservoirs (soils, wetlands, tarns) occurred when monthly rainfall exceeded 90 mm. In dry years there were lower water yields with less effective hydrological regulation. In average years the differences between input and output in watershed balances were very small.

Conclusions: The high and constant evapotranspiration of the wetlands and tarns (due to permanent water availability) suggests they could maintain streamflow during dry periods. Their high evapotranspiration rates are compensated by low rates in shrublands units, reducing the mean total evapotranspiration of the watershed. The watershed balances suggest a limited regulatory capacity in these relatively dry páramos with no volcanic soils.     

Growth form evolution and hybridization in Senecio (Asteraceae) from the high equatorial Andes

Changes in growth forms frequently accompany plant adaptive radiations, including páramo–a high‐elevation treeless habitat type of the northern Andes. We tested whether diverse group of Senecio inhabiting montane forests and páramo represented such growth form changes. We also investigated the role of Andean geography and environment in structuring genetic variation of this group. We sampled 108 populations and 28 species of Senecio (focusing on species from former genera Lasiocephalus and Culcitium) and analyzed their genetic relationships and patterns of intraspecific variation using DNA fingerprinting (AFLPs) and nuclear DNA sequences (ITS). We partitioned genetic variation into environmental and geographical components. ITS‐based phylogeny supported monophyly of a Lasiocephalus‐Culcitium clade. A grade of herbaceous alpine Senecio species subtended the Lasiocephalus‐Culcitium clade suggesting a change from the herbaceous to the woody growth form. Both ITS sequences and the AFLPs separated a group composed of the majority of páramo subshrubs from other group(s) comprising both forest and páramo species of various growth forms. These morphologically variable group(s) further split into clades encompassing both the páramo subshrubs and forest lianas, indicating independent switches among the growth forms and habitats. The finest AFLP genetic structure corresponded to morphologically delimited species except in two independent cases in which patterns of genetic variation instead reflected geography. Several morphologically variable species were genetically admixed, which suggests possible hybrid origins. Latitude and longitude accounted for 5%–8% of genetic variation in each of three AFLP groups, while the proportion of variation attributed to environment varied between 8% and 31% among them. A change from the herbaceous to the woody growth form is suggested for species of high‐elevation Andean Senecio. Independent switches between habitats and growth forms likely occurred within the group. Hybridization likely played an important role in species diversification.     

Microclimatic convergence of high-elevation tropical páramo and temperate-zone alpine environments

Abstract. Plant microclimates of three tropical superpáramo sites at 4100–4600 m a.s.l. in Ecuador were monitored over a five-month period and results were evaluated in local and biogeographical contexts. Soil temperatures tended to decrease with altitude, whereas quantum flux density (QFD) exhibited no consistent altitudinal pattern. Leaf temperatures of prostrate rosette and cushion plants exhibited diurnal amplitudes of 30 °C independent of altitude, while herbaceous perennials and woody shrubs, which were situated higher above the soil surface, had lower maxima and lower daily amplitudes as a result of aerodynamic coupling to the atmosphere. Long-term growth measurements and an analysis of a stem cross-section of the shrub Loricaria indicated that growth conditions at 4060 m a.s.l. were constant over a 4-yr to > 25-yr period. Means and frequency distributions of QFD as well as soil and leaf temperatures in the Ecuadorean Andes closely resemble growing season averages at high alpine sites in the European Central Alps at 2600 m a.s.l. Equivalent growth conditions in equatorial tropical páramo sites and seasonal temperate zone mountains extending to the arctic, suggest that, aside from the duration of the growing season, similar abiotic selection pressures operate on high elevation plants in humid mountain ecosystems, which are largely independent of latitude.     

Factors Controlling Compositional Changes in a Northern Andean Páramo (La Rusia,Colombia)

In this study, we aimed to assess the processes controlling compositional change in a Northern Andean páramo highly affected by human‐induced disturbances over the last few decades (La Rusia, Colombia). Along the 3000–3800 m asl altitudinal range, we randomly sampled fifty 10 × 10 m plots. Therein, we measured altitude and variables related to soil conditions (i.e., moisture, nutrient contents, bulk density, and texture), occurrence of human‐induced disturbances (i.e., fire, vegetation clearing, potato cultivation, and cattle grazing), and land‐use history. We also recorded richness and abundance of plant species, identifying them as exotic or native. We differentiated four groups of plots according to their species composition. The groups had significant differences in altitude, soil conditions, land‐use history, and particularly, in richness of exotic species and exotic/native cover ratio. They could be ascribed to shrub‐ and grass‐páramo vegetation types based on their relative dominance of woody and herbaceous species; however, these groups were not arranged according to the hypothetical composition of altitudinal belts, but rather formed a mosaic of patches. This mosaic was determined not only by altitude but also by soil conditions and disturbance history of sites. Our results corroborate recent findings which highlight shrub‐ and grass‐páramo vegetation types as patches of contrasting species composition and structure that depend on local environmental variables, as well as human‐induced disturbances as a major determinant of compositional discontinuities in these ‘high mountain’ tropical ecosystems.     

Plutarchia ecuadorensis (Ericaceae,Vaccinieae): a new species and a new generic record for Ecuador

Plutarchia, a shrubby páramo genus, is here reported for the first time in Ecuador where two species are recognized: P. angulata A. C. Smith and the new P. ecuadorensis Luteyn. These two species are keyed, described, and the new species illustrated.     

Late Holocene vegetation, fire, climate and upper forest line dynamics in the Podocarpus National Park, southeastern Ecuador

Late Holocene vegetation, fire, climate and upper forest line dynamics were studied based on detailed pollen and charcoal analyses. Two sediment cores, from the Rabadilla de Vaca mire (RVM) and the Valle Peque?o bog (VP), with an age of about 2100 and 1630 cal yrs b.p., respectively, were taken at the modern upper forest line in the Parque Nacional Podocarpus (Podocarpus National Park) in southeastern Ecuador. The two pollen records reflect relatively stable vegetation with slight changes in floral composition during the recorded period. Changes of the proportion between subpáramo and páramo vegetation are related to lower and higher frequency of fires. The RVM records show that the upper forest line moved to a higher elevation between 1630 and 880 cal yrs b.p., stabilising after 310 cal yrs b.p. Human impact is suggested by a high fire frequency, mainly between 1800–1600 and 880–310 cal yrs b.p. The VP records indicate no marked changes in the upper forest line. The charcoal records suggest an increased human impact from 230 cal yrs b.p. to the present. The results indicate that high fire frequency is an important factor in reducing the expansion of subpáramo vegetation and upper montane rainforest and in favouring the distribution of grass páramo. Since there is a clear correlation between fire and vegetation dynamics, it is difficult to detect how far climate change also played a significant role in upper forest line changes during the late Holocene.     

Three new species of Lysipomia (Lobeliaceae) endemic to the páramos of southern Ecuador

Three species of Lysipomia, L. caespitosa, L. cylindrocarpa, and L. speciosa, from a tropical alpine ecosystem called páramo, are described, illustrated, and compared to related species. Notes on morphology, especially floral presentation, and general ecology are given where possible. A published key to the species in Ecuador is revised to include the three new species plus L. multiflora McVaugh, a species previously known only from northern Peru.