Vegetation structure and aboveground biomass of Páramo peatlands along a high-elevation gradient in the northern Ecuadorian Andes

The high-elevation peatlands of the páramos of the northern Andes constitute a diverse environment that harbors large numbers of species and several types of plant communities along altitudinal, latitudinal, and environmental gradients. However, little is known about the structure and functioning of these ecosystems, including peatland vegetation types and their relative contribution to the production and accumulation of peat soils. In this paper we characterized the structure of peatland plant communities of the humid páramos of northern Ecuador by describing the distribution of plant growth-forms and their aboveground biomass patterns. Along an elevation gradient of 640 m we sampled vegetation in 16 peatlands and aboveground biomass in four peatlands. Three distinct peatland vegetation types were identified: High elevation Cushion peatlands, dominated by Plantago rigida and Distichia muscoides, Sedge and rush peatlands dominated by Carex spp. and Juncus spp., and Herbaceous and shrubby peatlands, with a more heterogenous and structurally complex vegetation. In terms of aboveground biomass, we found an 8-fold reduction in the higher peatlands compared to the lower sites, suggesting that the steep elevational gradients characteristic of Andean environments might be crucial in structuring the physiognomy and composition of peatland vegetation, either through its effects on temperature and other environmental factors, or through its effects on the age and development of soils. Additional studies are needed to evaluate the potential effects of temperature, hydrology, micro-topography, geological setting, and land-use, which are likely to influence vegetation patters in these peatlands.

Effect of agricultural activities on surface water quality from páramo ecosystems

Páramos are high mountain ecosystems strategic for water provision in South America. Currently, páramos are under threat due to agricultural intensification that impairs surface water sources. This research analyzed the effect of agriculture (spring onion-Allium fistulosum, potato-Solanum tuberosum, and livestock farming) on water quality in páramo ecosystems. A Hydrographic Unit upstream of the Jordan river catchment (Colombia) was selected and monitored in two different rainfall regimes, following the paired catchments and upstream-downstream approaches to compare water quality from natural and anthropic areas. Twenty-two parameters related to agricultural activities were analyzed (nutrients, salts, organic matter, sediments, and pathogens). The studied agricultural activities increased loads of surface water in quality in nitrates (0.02 to 2.56 mg N-NO₃/L), potassium (0.13 to 1.24 mg K/L), and Escherichia coli (63 to 2718 FCU/100 mL), generating risks on the human health and promoting eutrophication. Total nitrogen and organic matter in the rainy season were higher than dry. BOD₅, COD, turbidity, and E. coli were above international standards for direct human consumption. However, water could be used for irrigation, livestock watering, and aquatic life ambient freshwater. The results show that a small land-use change of almost 15% from natural páramo vegetation to agricultural uses in these ecosystems impairs water quality, limiting its uses, and the need to harmonize small-scale livelihoods in the páramo with the sustainability of ecosystem service provision.

A new Colombian species of Liodessus diving beetles from the Páramo de Sumapaz (Coleoptera, Dytiscidae, Bidessini)

Liodessuspicinussp. nov. is described from the Páramo de Sumapaz near Bogota D.C. at 3,500 m above sea level. The species can be distinguished from the other Colombian Liodessus species by its dark coloration, discontinuous habitus, shiny surface of the pronotum and elytron, presence of a distinct occipital line, distinct basal pronotal striae, short or even faint basal elytral striae, as well as by its distinct geographic distribution and cox1 signature.

Ecosystem services show variable responses to future climate conditions in the Colombian páramos

Background

The páramos, the high-elevation ecosystems of the northern Andes, are well-known for their high species richness and provide a variety of ecosystem services to local subsistence-based communities and regional urbanizations. Climate change is expected to negatively affect the provision of these services, but the level of this impact is still unclear. Here we assess future climate change impact on the ecosystem services provided by the critically important páramos of the department of Boyacá in Colombia, of which over 25% of its territory is páramo.

Methods

We first performed an extensive literature review to identify useful species of Boyacá, and selected 103 key plant species that, based on their uses, support the provision of ecosystem services in the páramos. We collated occurrence information for each key species and using a Mahalanobis distance approach we applied climate niche modelling for current and future conditions.

Results

We show an overall tendency of reduction in area for all ecosystem services under future climate conditions (mostly a loss of 10% but reaching up to a loss of 40%), but we observe also increases, and responses differ in intensity loss. Services such as Food for animals, Material and Medicinal, show a high range of changes that includes both positive and negative outcomes, while for Food for humans the responses are mostly substantially negative. Responses are less extreme than those projected for individual species but are often complex because a given ecosystem service is provided by several species. As the level of functional or ecological redundancy between species is not yet known, there is an urgency to expand our knowledge on páramos ecosystem services for more species. Our results are crucial for decision-makers, social and conservation organizations to support sustainable strategies to monitor and mitigate the potential consequences of climate change for human livelihoods in mountainous settings.

Atmosphere-surface fluxes modeling for the high Andes: The case of páramo catchments of Ecuador

Interest in atmosphere-surface flux modeling over the mountainous regions of the globe has increased recently, with a major focus on the prediction of water, carbon and other functional indicators in natural and disturbed conditions. However, less research has been centered on exploring energy fluxes (net radiation; sensible, latent and soil heat) and actual evapotranspiration (ETa) over the Neotropical Andean biome of the páramo. The present study assesses the implementation and parameterization of a state-of-art Land-Surface Model (LSM) for simulation of these fluxes over two representative páramo catchments of southern Ecuador. We evaluated the outputs of the LSM Community Land Model (CLM ver. 4.0) with (i) ground-level flux observations from the first (and highest) Eddy Covariance (EC) tower of the Northern Andean páramos; (ii) spatial ETa estimates from the energy balance-based model METRIC (based on Landsat imagery); and (iii) derived ETa from the closure of the water balance (WB). CLM's energy predictions revealed a significant underestimation on net radiation, which impacts the sensible and soil heat fluxes (underestimation), and delivers a slight overestimation on latent heat flux. Modeled CLM ETa showed acceptable goodness-of-fit (Pearson R = 0.82) comparable to ETa from METRIC (R = 0.83). Contrarily, a poor performance of ETa WB was observed (R = 0.46). These findings provide solid evidence on the CLM's accuracy for the ETa modeling, and give insights in the selection of other ETa methods. The study contributes to a better understanding of ecosystem functioning in terms of water loss through evaporative processes, and might help in the development of future LSMs' implementations focused on climate / land use change scenarios for the páramo.

Two new species of Dendrophthora (Viscaceae) from the Venezuelan Andes

Two new species of Dendrophthora Eichler (Viscaceae) from northwestern Venezuela are described and illustrated. Both mistletoes, D. apiculata Canelón et al., sp. nov. and D. coronata Canelón et al., sp. nov., are confined to subpáramo and páramo ecosystems of the Venezuelan Andes and are, at present, only known from Guaramacal National Park (Portuguesa and Trujillo states). Ecological aspects and possible taxonomic affinities are discussed. A distribution map also is presented.

The role of dispersal for shaping phylogeographical structure of flightless beetles from the Andes

Background

Páramo is a tropical alpine ecosystem present in the northern Andes. Its patchy distribution imposes limits and barriers to specialist inhabitants. We aim to assess the effects of this habitat distribution on divergence across two independently flightless ground beetle lineages, in the genera Dyscolus and Dercylus.

Methods

One nuclear and one mitochondrial gene from 110 individuals from 10 sites across the two lineages were sequenced and analyzed using a combination of phylogenetics, population genetic analyses, and niche modeling methods.

Results

The two lineages show different degrees of population subdivision. Low levels of gene flow were found in Dyscolus alpinus, where one dominant haplotype is found in four out of the six populations analyzed for both molecular markers. However, complete population isolation was revealed in species of the genus Dercylus, where high levels of differentiation exist at species and population level for both genes. Maximum entropy models of species in the Dercylus lineage show overlapping distributions. Still, species distributions appear to be restricted to small areas across the Andes.

Conclusion

Even though both beetle lineages are flightless, the dispersal ability of each beetle lineage appears to influence the genetic diversity across fragmented páramo populations, where Dyscolus alpinus appears to be a better disperser than species in the genus Dercylus.

Carbon sequestration and methane emissions along a microtopographic gradient in a tropical Andean peatland

Tropical alpine peatlands are among the least studied wetlands types on earth. Their important ecosystem services at local and regional scope are currently threatened by climate and land use changes. Recent studies in these ecosystems suggest their importance to the provision of climate regulation services, prompting a better understanding of the underlying functions and their variability at ecosystem scales. The objective of this study is to determine the variability of methane (CH₄) fluxes and carbon (C) sequestration within a tropical alpine peatland in three locations along a microtopographic gradient and its associated plant diversity. These locations accounted for: 1) hummocks, found mostly near the edge of the peat with a water table below the soil surface, 2) lawns, in the transition zone, with a water-table near the soil surface, and 3) hollows, permanently flooded with a water table above the soil surface, composed of small patches of open water intermingled with unconsolidated hummocks that surface the water level. Results indicate that CH₄ flux is lowest in the lawns, while C sequestration is highest. Conversely, the hummock and hollow have higher CH₄ flux and lower C sequestration. In addition, plant diversity in the lawns is higher than in the hummock and hollow location. Dryer conditions brought by current climate change in the northern Andes are expected to lower the water tables in the peatland. This change is expected to drive a change in CH₄ flux and C sequestration at the lawns, currently dominating the peatland, towards values more similar to those measured in the hummocks. This decrease may also represent a change towards the lower plant diversity that characterized the hummock. Such changes will reduce the ratio of C sequestration:CH₄ flux signifying the reduction of resilience and increment of vulnerability of the climate-regulating service to further perturbations.

Impact of potato cultivation and cattle farming on physicochemical parameters and enzymatic activities of Neotropical high Andean Páramo ecosystem soils

The Andean Páramos are high mountain ecosystems whose soils are essential for the management of South American water resources, but research on anthropic impacts to these soils is currently minimal and insufficient. The objective of this study was to evaluate the impacts of potato (Solanum tuberosum) cultivation and livestock on the physicochemical parameters and enzymatic activities that determine the soil quality of the Neotropical high Andean Páramo ecosystem in the Nevados National Natural Park (Nevados NNP) in Colombia. It was hypothesised that sites with potato crops and livestock farming would exhibit significant changes in soil physicochemical parameters and enzymatic activities compared with Páramo sites that have been conserved without agriculture. Samples were collected from soils under potato cultivation, livestock and Páramo (subject to the lowest degree of human intervention possible), on three farms in the El Bosque District at three different altitudes (Buenos Aires, El Edén and La Secreta) during two seasons (dry and rainy). The results showed that none of the physical parameters under study presented statistically significant differences due to the type of use (livestock, potato crop or Páramo), season of sampling (dry or rainy season) or altitude (different farms). The chemical parameters that statistically significantly differed due to land use were organic carbon, cation exchange capacity, calcium, potassium, and ammonium and those that showed statistically significant differences associated with the sampling timing were organic carbon, nitrogen, cation exchange capacity, total carbon, C/N and nitrate. Additionally, there were differences in organic carbon due to the altitude of the farms. With respect to enzymatic activities, those of β-glucosidase, phosphodiesterase and urease significantly decreased in soils under potato cultivation and livestock relative to those of Páramo, but those of acid phosphatase and protease increased significantly under potato cropping and livestock. The activities of β-glucosidase, acid phosphatase, alkaline phosphatase, phosphodiesterase and protease were higher during the dry season than the rainy season, and the activities of β-glucosidase, acid phosphatase and urease decreased statistically in the lower-altitude farm (La Secreta). These decreases in enzymatic activities are attributable to changes in the organic carbon of the soil. This study provides a novel insight on the relationships between land use and the physicochemical parameters and enzymatic activities of Páramo soils (which have been minimally studied to date) at different altitudes and during different seasons. The results suggest that changes in agricultural practices should be implemented to maintain the organic carbon of soil and, therefore, its enzymatic activities.

Rampant polyphyly in the Arracacia clade (Apiaceae) and an assessment of the phylogenetic utility of 20 noncoding plastid loci

The Arracacia clade (Apiaceae, Apioideae) is a heterogeneous assemblage of 12 genera, comprising 111 known species distributed in high montane temperate and sub-alpine habitats of meso- and South America. Previous studies have indicated that the genera Arracacia, Coulterophytum, and Prionosciadium are polyphyletic, but for the most part relationships among the members of the clade are largely unknown. Initially, cladistic analyses of nrDNA ITS sequences were carried out on 212 accessions (122 taxa), representing 92 species of the Arracacia clade and outgroups from the closely-related páramo genera Cotopaxia, Niphogeton, and Perissocoeleum and members of the Perennial Endemic North American clade and its allies. Using the ITS results to inform sampling of a small subset of taxa, a pilot study examining the phylogenetic utility of 20 noncoding chloroplast loci was subsequently performed to identify those regions most useful at resolving relationships. A cost-benefit analysis determined that five loci (trnQ-5'rps16, trnD-trnT, rpl32-trnL, psbD-trnT, ndhA intron) would maximize resolution and branch support in the clade. Cladistic analyses of four of these loci (trnQ-5'rps16, trnD-trnT, rpl32-trnL, ndhA intron) and the ITS region, separately and combined, revealed that Arracacia, Coaxana, Coulterophytum, Prionosciadium, and Rhodosciadium are each polyphyletic and that Donnellsmithia and Myrrhidendron are each monophyletic. Although most relationships in the Arracacia clade and among the closely-related genera Cotopaxia, Niphogeton, and Perissocoeleum are poorly resolved and supported, ten groups are recognized for future revisionary studies. Polyploidy and rapid species radiation have likely confounded generic circumscriptions and interpretation of relationships.

Communal Participation in Payment for Environmental Services (PES): Unpacking the Collective Decision to Enroll

Payment for Environmental Service programs are increasingly applied in communal settings where resource users collectively join the program and agree to limit their shared use of a common-property resource. Who decides to join PES and the degree to which community members agree with the collective decision is critical for the success of said programs. Yet, we have limited understanding of the factors that influence communal participation and the collective decision process. This paper examines communal participation in a national payment for conservation program in Ecuador. We use quantitative and qualitative analysis to (i) identify the attributes of the communities that participate (or not), and factors that facilitate participation (n = 67), and (ii) assess household preference and alignment with the collective decision to participate (n = 212). Household participation preferences indicate varying degrees of consensus with the collective decision to participate, with those using the resource less likely to support participation. At the communal level, however, our results indicate that over time, those communities that depend more heavily on their resource systems may ultimately choose to participate. Our findings suggest that communal governance structures and outside organizations may be instrumental in gaining participation in resource-dependent communities and building consensus. Findings also point to the need for further research on communal decision-processes to ensure that the collective decision is based on an informed and democratic process.

Community trees: Identifying codiversification in the Páramo dipteran community

Groups of codistributed species that responded in a concerted manner to environmental events are expected to share patterns of evolutionary diversification. However, the identification of such groups has largely been based on qualitative, post hoc analyses. We develop here two methods (posterior predictive simulation [PPS], Kuhner-Felsenstein [K-F] analysis of variance [ANOVA]) for the analysis of codistributed species that, given a group of species with a shared pattern of diversification, allow empiricists to identify those taxa that do not codiversify (i.e., "outlier" species). The identification of outlier species makes it possible to jointly estimate the evolutionary history of co-diversifying taxa. To evaluate the approaches presented here, we collected data from Páramo dipterans, identified outlier species, and estimated a "community tree" from species that are identified as having codiversified. Our results demonstrate that dipteran communities from different Páramo habitats in the same mountain range are more closely related than communities in other ranges. We also conduct simulation testing to evaluate this approach. Results suggest that our approach provides a useful addition to comparative phylogeographic methods, while identifying aspects of the analysis that require careful interpretation. In particular, both the PPS and K-F ANOVA perform acceptably when there are one or two outlier species, but less so as the number of outliers increases. This is likely a function of the corresponding degradation of the signal of community divergence; without a strong signal from a codiversifying community, there is no dominant pattern from which to detect an outlier species. For this reason, both the magnitude of K-F distance distribution and outside knowledge about the phylogeographic history of each putative member of the community should be considered when interpreting the results.

Shifts in diversification rates linked to biogeographic movement into new areas: An example of a recent radiation in the Andes

PREMISE OF THE STUDY

Clade-specific bursts in diversification are often associated with the evolution of key innovations. However, in groups with no obvious morphological innovations, observed upticks in diversification rates have also been attributed to the colonization of a new geographic environment. In this study, we explore the systematics, diversification dynamics, and historical biogeography of the plant clade Rhinantheae in the Orobanchaceae, with a special focus on the Andean clade of the genus Bartsia.

METHODS

We sampled taxa from across Rhinantheae, including a representative sample of Andean Bartsia species. Using standard phylogenetic methods, we reconstructed evolutionary relationships, inferred divergence times among the clades of Rhinantheae, elucidated their biogeographic history, and investigated diversification dynamics.

KEY RESULTS

We confirmed that the South American Bartsia species form a highly supported monophyletic group. The median crown age of Rhinantheae was determined to be ca. 30 Myr, and Europe played an important role in the biogeographic history of the lineages. South America was first reconstructed in the biogeographic analyses around 9 Myr ago, and with a median age of 2.59 Myr, this clade shows a significant uptick in diversification.

CONCLUSIONS

Increased net diversification of the South American clade corresponds to biogeographic movement into the New World. This movement happened at a time when the Andes were reaching the necessary elevation to host an alpine environment. Although a specific route could not be identified with certainty, we provide plausible hypotheses to how the group colonized the New World.

Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

A nomenclator for the frailejones (Espeletiinae Cuatrec., Asteraceae)

The páramos and high Andean forests of the tropical Andes are largely dominated by frailejones (Nomen nudum Cuatrec., Nomen nudum). These plants are ecologically and culturally essential for both ecosystems and local inhabitants. The frailejones have been studied for over two centuries, but the taxonomic knowledge is still sparse and incomplete. The inedited monograph by Cuatrecasas contains only ca. 70% of the species known today, and publications in the last decade disagree regarding the number of taxa within the group, with estimates ranging from 3 genera and 90 species to 8 genera and 154 species. Moreover the literature contains inexact information about their distribution. As part of a study of the phylogenetic and biogeographic relationships of the group, a thorough revision of the nomenclature was needed as a first step. Currently the subtribe has 8 recognized genera, 141 species, 17 subspecies, 22 varieties, 8 forms, 33 recognized hybrids, 142 synonyms and 5 invalid names, for a total of 368 names (autonyms not counted). The most current list of taxa is presented here, along with some notes and Spanish names. Tamananthus crinitus V.M.Badillo is not included within the subtribe. Various previous species or infraspecific taxa (i.e. Carramboa tachirensis (Aristeg.) Cuatrec., Espeletia algodonosa Aristeg., Espeletia aurantia Aristeg., Espeletia brassicoidea var. macroclada, Espeletia brassicoidea var. pedunculata,Espeletia garcibarrigae Cuatrec. and Espeletiopsis cristalinensis (Cuatrec.) Cuatrec.) are proposed or confirmed as hybrids. Two new records for Colombia are mentioned: Ruilopezia cardonae (Cuatrec.) Cuatrec., which is the first report of Ruilopezia for that country, and Espeletia steyermarkii Cuatrec. Observations regarding the frequency of hybrids in the subtribe are also given.