Influence of local and landscape environmental factors on alpha and beta diversity of macroinvertebrates in Andean rivers

Research on macroinvertebrate community structure in Andean rivers has been oriented towards describing patterns of alpha and gamma diversity by taking into account environmental predictors at local spatial scales(e.g.,micro-and mesohabitats).However,the patterns of beta diversity and the importance of landscape-scale variables have been evaluated to a lesser extent.The objective of this study was to describe the patterns of alpha and beta diversity of benthic macroinvertebrates in the Andean rivers of the Orinoco basin and their relationship with local and landscape environmental variation.A stratified random sampling of macroinvertebrates was carried out at 40 sites(comprising an altitudinal range of between 500 and 2900 m.a.s.l.),local and landscape variables were measured.Our results showed that the variation of alpha diversity was influenced by local and landscape variables,which are directly and indirectly related to the contribution of sediments,substrate composition and flow velocity,providing a heterogeneity of habitats.Global beta diversity was explained by the combined effect of local and landscape variables.Regarding the beta diversity phenomena,turnover was predominant while nestedness presented a minor contribution and both were explained in greater proportion by local descriptors and some landscape variables,specifically those of a geomorphological nature.Our results concur with the view of an environmental and spatial hierarchy within the river habitat and highlight the influence of multiple scales on macroinvertebrate diversity.The above suggests that both local and landscape scales must necessarily be considered for environmental management and the conservation of Andean lotic ecosystems.

Antioxidant activity of six essential oils and its molecules in Ecuadorian Andean medicinal plants

Background:This research values the antioxidant activity and its responsible molecules in six essential oils from medicinal plants in the Ecuadorian Andes.Methods:The chemical composition of essential oils was determined using gas chromatography coupled mass spectrometry.For evaluated the antioxidant activity of essential oils was use tree spectrophotometric methods:diphenyl-1-picrylhydrazyl(DPPH),2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)andβ-Carotene bleaching test.The essential oils with good activity were determined the responsible molecules using the Bioautographic HP-TLC-DPPH method.Results:The scavenging capacity of the radicals was assessed with DPPH and ABTS methods,the best results were found in the oils of M.mollis IC_(50) DPPH 2.80 mg/ml and IC_(50) ABTS 0.205 mg/mL and in A.glutinosa IC_(50) DPPH 12.972 mg/mL and IC_(50) ABTS 0.321 mg/mL,the results were compared with a pattern of natural reference in this case,the essential oil of T.vulgaris IC_(50) DPPH 0.474 mg/mL and IC_(50) ABTS 0.272 mg/mL.The evaluation of the antioxidant activity was determined by theβ-carotene bleaching test,the most notable activity results were from M.mollis IC_(50)0.119 mg/mL,A.glutinosa IC_(50)0.062 mg/mL and B.latifolia IC_(50)0,064 mg/mL.DPPH bioautography revealed the active molecules antioxidants in oils for M.mollis were thymol acetate(7.73%)and carvacrol acetate(24.52%),for A.glutinosa wasγ-muurolene(2.68%),and for B.latifolia Z-caryophyllene(2.99%),aristolochene(0.11%)and cis-cadin-4-en-7-ol(4.11%).Conclusion:The results of antioxidant activity shown in descending order that the essential oils of:M.mollis,A.glutinosa and B.latifolia,are those with the highest activity using the DPPH and ABTS methods.Theβ-Carotene bleaching test method confirms the 3 oils as the most active in the following order:A.glutinosa,B.latifolia and M.mollis.An antioxidant bioautographic study identified the molecules responsible for the activity in three essential oils with good activity.

Andean adakites：three ways to make them安第斯埃达克岩：三种成因模式

在安第斯埃达克岩是常见的。由这种岩石的痕量元素特征揭示的高压组成矿物，表明其有三种可能的成因。这三种成因按相对重要性依次为：安第斯地壳的构造加厚；弧前壳的俯冲-侵蚀；年轻洋壳的俯冲。在过去300Ma，每种成因模式的埃达克岩在智利-阿根廷安第斯地区均有喷发。它们的产状与智利-阿根廷边缘快速变化的构造背景中特定构造条件和事件相吻合。埃达克岩在过去安第斯边缘的产状可望成为矿化的优异构造标志，也可用于指导找矿。

Generation of andesite through partial melting of basaltic metasomatites in the mantle wedge:Insight from quantitative study of Andean andesites

Continental crust in average exhibits a similar composition in both major and trace elements to andesites along active continental margins.For this reason,andesitic magmatism above oceanic subduction zones is considered to have played a key role in the generation of continental crust along convergent plate boundaries.With respect to the origin of andesites themselves,however,there is still a hot debate on how they have acquired their geochemcial compositions.The debate is mainly centralized on the relative contributions of crustal contamination,magma differentiation and source mixing,which reaches an impasse in the past decades.The essential reason for this kind of debates is that these three mechanisms only can account for some of the geochemical observations for andesites,leading to insufficient discrimination among them.Nevertheless,the geochemical features of andesites are primarily controled from early to late by the composition of their source rocks in addition to partial melting and magma differentiation processes.If source mixing and partial melting processes in the early stage of andesite magmatism can account for the first-order geochemical features of andesites,there is no need to invoke the late processes of magma differentiation and crustal contamination for andesite petrogenesis.This is illustrated by quantitative forward modeling of the geochemical data for Quaternary andesites from the Andean arc in South America based on an integrated interpretation of these data.The modeling has run with four steps from early to late:(1)dehydration of the subducting oceanic crust at forearc depths;(2)partial melting of the subducting terrigenous sediment and altered oceanic basalt at subarc depths to produce hydrous felsic melts;(3)the generation of basaltic metasomatites(e.g.,Si-excess pyroxenite)in the mantle wedge through reaction of the mantle wedge peridotite with large amounts of the hydrous felsic melts;(4)the production of andesitic melts by partial melting of the basaltic metasomatites.The results not only testify the hypothesis that the trace element and radiogenic isotope compositions of andesites can be directly produced by the source mixing and mantle melting but also demonstrate that partial melting of the basaltic metasomatites can reproduce the lithochemical composition of andesites.The compositional variations of Andean andesites within a single volcanic zone and among different volcanic zones can be explained by incorporating different amounts of heterogeneous hydrous felsic melts into their mantle sources,followed by different degree of partial melting under different pressures and temperatures.Therefore,the source mixing and partial melting processes at subarc depths can account for the first-order geochemical features of Andean andesites.In this regard,it may be not necessary for andesite petrogenesis to invoke the significant contributions from the processes of magma differentiation and crustal contamination.

Selective Permeation of CO_2 Through Modified PVSA/PS Composite Membrane

A new fixed carder membrane material VSA-SA for CO2 separation was prepared through the chemical modification of PVSA. The selective permeation of CO2 through VSA-SA/PS composite membrane was performed with CO2/CH4 system. The VSA-SA/PS composite membranes possess better CO2 permselectivity than PVSA/PS composite membrane. Keywords： Fixed carder membrane, CO2 separation, PVSA, VSA-SA.

Bouguer Gravity Anomaly in the Andean Orogenic Belt and its Dynamic Implications for Regional Tectonic Evolution

Calculated Bouguer gravity anomalies from the Andean orogenic belt interpreted as derived from regional gravity data to aid understanding of the lithospheric structure and tectonic evolution of the belt.These anomalies reveal lithospheric structures distributed throughout the belt,including linear and circular structures.NE-trending structures reflect sinistral transpression across the northern part of the belt,and NW-trending structures represent dextral transtension in the southern part.These results are supported by gravity-anomaly patterns that demonstrate mantle flow in a trench-parallel direction both northward and southward away from the stagnation band that is beneath the subducting Nazca slab.This mantle flow has served as an important driving force in the evolution of the Andean orogenic belt.Features of the modified tectonic model of the Andean orogenic belt are consistent with the spatial variation in and interpretation of Bouguer gravity anomalies.

Forest Biodiversity Assessment in Peruvian Andean Montane Cloud Forest

Cloud forests are unusual and fragile habitats, being one of the least studied and least understood ecosystems. The tropical Andean dominion is considered one of the most significant places in the world as regards biological diversity, with a very high level of endemism. The biodiversity was analysed in an isolated remnant area of a tropical montane cloud forest known as the "Bosque de Neblina de Cuyas", in the North of the Peruvian Andean range. Composition, structure and dead wood were measured or estimated. The values obtained were compared with other cloud forests. The study revealed a high level of forest biodiversity, although the level of biodiversity differs from one area to another: in the inner areas, where human pressure is almost inexistent, the biodiversity values increase. The high species richness and the low dominance among species bear testimony to this montane cloud forest as a real enclave of biodiversity.

Changes during Cooking Processes in 6 Varieties of Andean Potatoes (<i>Solanum tuberosum</i>ssp. Andinum)

The value of the native potato varieties grown in Argentinean northwest lies both in their fundamental role as a source of food for the population and in their potential for the development of new products. The aim of this work was to study the changes produced by two common cooking processes (boiling and frying) on the nutritional, textural and functional characteristics of five Andean potatoes varieties. The cooking process (boiling) does not significantly affect the composition of potatoes, but there are losses of vitamin C;a greater loss was observed when they were boiled shelled. In frying potatoes vitamin C is completely destroyed. Resistant starch values between 0.90 and 4.58 g/100g of potato were found for raw Andean varieties;they decreased during the cooking process (boiled) (0.15 to 0.54 g/100g of potato) and increased again to be stored for 48 h at 4&degC (0.73 - 1.88 g/100g of potato). The frying process produced an increment in energy value between 92% and 148% according to variety. Regarding to the fracture strength and hardness, no significant differences were observed between the Andean varieties and the control (Spunta) at the initial or final stages, but there were differences during the intermediate stages.

Effects of micro-environmental conditions and forest disturbance on the establishment of two Andean palms in Ecuador

The wax palm (Ceroxylon echinulatum) and palm heart (Prestoea acuminata) are key elements in Andean natural forests. This ecosystem is threatened by deforestation and habitat degradation, thus, it is vital to explore the impact of anthropogenic activities on the ecological structure and preferences of these species in order to develop proper conservation strategies. Fifty-seven 400 m2 plots were established in two forest areas, a disturbed forest (n = 30 plots) and an undisturbed forest (n = 27 plots) in the Ecuadorean Andes. Nine micro-environmental variables and the number of individuals of C. echinulatum and P. acuminata in five size classes were recorded in each plot. Logistic regression models helped identify environmental variables that influence the establishment of the species. Results showed that different micro-environmental variables determined the presence of different size classes. Both species were benefitted by the environmental conditions of the disturbed forest. Light availability was important for the establishment of both species, especially for the canopy species (C. echinulatum). This palm was negatively affected by the variable “fallen wood”, while P. acuminata was negatively affected mainly by the steepness of the terrain. The environmental variables for the successful establishment of the studied species that were identified by this study provide clues for the sustainable management of C. echinulatum and P. acuminata in Andean forests.

Landscapes of Andenes and Sustainable Infrastructure in Andean Cities

This article aims to analyze cities located in the high mountain ecosystems formed by the landscape of Andenes or sustainable infrastructure of terraces located in the Ecuadorian and Peruvian Andean highlands of central South America. The selected case studies have in common the use of land for settlement purposes, and the fact that they pursue both urban and rural infrastructure sustainability approaches. Theoretical and empirical methods were used such as the historical-logical method, the inductive-deductive method, observation in situ and reviews of documents and maps. It is concluded that the anthropic interventions and the management and monitoring plans of each site allow for the conservation of their natural resources and of the landscape of Andenes, the improvement of the population’s quality of life, the control of structural risk to prevent erosion of the mountains where they are constructed as well as the preservation of the site’s globally significant cultural heritage (as recognised by UNESCO). Current trends in the sustainable use of cultural and natural resources of the heritage involve the conservation of terraced landscapes. Without their preservation, management or exploitation as a tourist resource cannot be carried out.

Appraisal of Five Clinical Guidelines for the Management of Hypertension in Andean Countries and Europe

There is global concern on the methodological limitations, transferability and effectiveness of clinical practice guidelines (CPGs) for chronic non-communicable diseases, particularly for hypertension. Bolivia, Ecuador and Peru have regularly produced CPGs;however no formal assessment has been done on their contents, transferability and effectiveness. The past decade saw significant migration from Andean countries to Europe. Knowing how European CPGs compare with those produced in Andean countries is necessary to recommend future changes targeted to the migrant population. A systematic search of CPGs was done on indexed databases and non-indexed publications. Recognized and approved CPGs were identified by technical officers in the Ministries of Health of the respective countries. The guidelines of the European Society of hypertension and four selected CPGs from the Andean countries were assessed by two independent evaluators using the “Agree II instrument for assessing clinical practice guidelines, AGREE II Consortium, May 2009”. Comparison of the CPGs is based on the six domain scores provided by the Agree II instrument. The overall score of CPGs ranged from 1.85 to 2.94 of 6 maximum possible. The European CPG scored highest in 3 of 6 domains compared, most notably in rigor of development. Average domain scores for clarity of presentation (0.84) and scope and purpose (0.64) were highest scores for applicability (0.30). Stakeholder involvement (0.28) and rigor of development (0.17) were the lowest. The CPGs assessed appear to fail meeting the standards of quality and pertinence. They show a progressive worsening from domains declaring good intentions of being clear, to those which measure their hard aspects and implications.

A Review on Tectonic Record of Strain Buildup and Stress Release across the Andean Forearc along the Gulf of Guayaquil-Tumbes Basin (GGTB) near Ecuador-Peru Border

Gravimetric and geologic data show that the reactivation of the Neogene Interandean depression and/or the ~75 - 65 Ma ophiolite suture into the modern dynamic of the Andes controlled the Gulf of Guayaquil Tumbes basin (GGTB) location and evolution during the past 1.8 - 1.6 Myr at least. Depending on whether the remobilization occurred along the interandean depression or the ophiolite suture, the GGTB evolved trough pure or simple shear mechanisms, respectively. Because the GGTB exhibits an along strike tectonic asymmetry associated with a pervasive seismic gap, the simple shear solution is more likely. Tectonic inversion occurred along a mid-crust detachment (the Mid-Crust detachment hereafter) matching the ophiolite suture that accommodates the North Andean Block (NAB) northward drift. The so-called Decoupling Strip located at the shelf slope break accommodated the tensional stress rotation from N-S along the shelf area i.e. NAB-drift induced to E-W along the continental margin i.e. subduction-erosion-induced. The landward dipping Woollard detachment system located at the Upper-Lower slope boundary connects the subduction channel at depth, allowing the Upper slope to evolve independently from the Lower slope wedge. The long-term recurrence interval between earthquakes, the strong interplate coupling, and the aseismic creeping deformation acting along the main low-angle detachments i.e. the Woollard and the Mid-Crust detachments may account for the pervasive seismic gap at the GGTB area. Because the subduction channel exhibits no record of significant seismic activity, no evidence exists to establish a link between the GGTB sustained subsidence and a basin-centered asperity. Because the GGTB is a promising site of hydrocarbon resources, to understand processes at the origin of this escape-induced forearc basin has a major economic interest.

Volunteering Tourism and Sustainable Development: A Case Study of an Andean Indigenous Project: Quilla Pacari, Chimborazo

Volunteering tourism incorporates services and activities related to the caring of environmental, cultural, or humanitarian issues, intending to benefit not only tourists but also locals. Therefore, this activity fits into principles of sustainable development which has been defined as growth based on a balance between the environmental, social, and economic dimensions. The aim of this study was to determine the contribution of volunteering tourism to sustainable development and to identify the crucial factors to implement a successful volunteering project. We explored the interactions between volunteering tourism and sustainable development through a qualitative approach considering as case study: the rural tourism project “Quilla Pacari”, located in the highlands of Chimborazo province, Ecuador. Our findings proportionate information about the influence of volunteering tourism in principles associated with sustainable development revealing a general insight into the interactions and identifying the perception about the crucial factors to implement a successful volunteering project. However, the Quilla Pacari project located in Chimborazo province is relatively emergent and further studies are needed to clarify all the relations associated with the process.

Conversion of Andean montane forest to exotic forest plantation modifies soil physicochemical properties in the buffer zone of Ecuador's Podocarpus National Park

Background:Andean montane forests(AMF)are biodiversity hotspots that provide fundamental hydrological services as well as carbon storage and sequestration.In recent decades,southern Ecuador AMFs have been seriously threatened by increased logging and conversion to forest plantations with exotic species.In this context,our main objective was to evaluate the effects of AMF conversion to forest plantations on soil physicochemical properties in the buffer zone(Bz)of the Podocarpus National Park(PNP),in southern Ecuador.For this purpose,random samples were taken at a depth of 0-10 cm in four plots in each contrast zone and analyzed for bulk density,porosity,textural class,leaf litter depth,soil pH,as well as the contents of organic matter(SOM),soil organic carbon(SOC),total nitrogen,and available phosphorus and potassium.Results:The results indicate that the conversion of AMFs produces an increase in bulk density and a decrease in SOM,SOC,and total nitrogen contents,thus modifying soil properties,which could result in a decrease in water regulation capacity and produce an increased risk of soil erosion.This accelerates degradation processes,as well as threatens shortages of the drinking water supply.Conclusions:This study can help decision-makers to implement soil management plans in the Bz of the PNP,based on the implementation of new regulations,where the conservation of AMF is promoted.In addition,it is recommended to apply environmental restoration strategies in the anthropized areas of the AMF,as well as in the areas with exotic eucalyptus and pine plantations.

Assessing the Effect of Natural Controls and Land Use Change on Sediment Yield in a Major Andean River:The Magdalena Drainage Basin,Colombia

马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络，该河流年产沙量约为150Mt，是全世界10大主要产沙河流之一。在本研究中，我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响，重建该区森林砍伐和农业活动时空模式，探讨土地利用变化与产沙趋势的关系。我们的研究结果表明，整个马格达莱纳河流域的产沙量可以用自然变量（包括径流量和最大河水流量）来解释。这两个因子解释了产沙量58％的变化。含沙率和土地利用的时间分析表明，在过去10～20年里流域侵蚀呈现增加的趋势。许多人类活动的影响，包括森林覆被在20年里减小了近40％．农业和牧场增加了65％、土壤保持差、开矿活动，以及城市化的加速，都促进了该地区域尺度上产沙量的增加。

Andean orogenic signature in the Quaternary sandy barriers of Southernmost Brazilian Passive Margin – Paradigm as a source area

Multiple source provenance of sediments and submarine fan formation are herein investigated based on Quaternary sandy barriers of the Brazilian Southernmost Coastal Plain.LA-ICP-MS dating on 1625 detrital zircons from marine and aeolian facies sands of four successive lagoon-barrier systems are analyzed.The characterization of Archean to Pleistocene zircons into a younger Andean(22±4 Ma to 1±1 Ma,48 from 1625),Mesozoic to Paleozoic,and Mesoproterozoic(479 from 1622)populations suggest that the main feeding of sediments to the coastal plain occurred through the La Plata River drainage system.The significant contribution of sediments is transported from the mouth of La Plata River northward by longshore circulation(littoral drift).Minor contributions are also recognized as.a farther source associatedwith the Patagonia drainage and nearby source related to the Uruguay/Rio Grande do Sul Shield and the ParanáBasin,drained by the Camaquãand Jacuírivers.The latter one is recognized by the contribution fromNeoproterozoic to Early Paleozoic,and some Paleoproterozoic and Archean zircon grains.The definition of the sources of clastic sediments allows inferences about the origination of Rio Grande Fan where both the cold Falkland and the warm Brazil currents played a major role.

Assessing the Influence of Global Climate and Anthropogenic Activities on the Water Balance of an Andean Lake

Tropical regions along the Andean Cordillera face an uncertain future as mountain lakes and snow peaks exhibit receding trends associated with factors such as climatic precursors and local anthropogenic activities. Tota, the largest mountain lake in the Colombian Andes, exemplifies the role played by these factors on the lake's hydrologic evolution. A monthly water balance in Tota Lake was performed using available hydrological information from 1958 to 2007 to address interannual and multiannual level fluctuations associated with human activities and climatic precursors. The balance shows that net water uses fluctuated around 2 m3/s during this period with a pattern that, although constrained during years of severe decline in lake levels, is able to explain most of the multiannual decaying trend of 1.5 cm/year in the last 50 years. The lake’s naturalized levels were used to determine the influence of climate precursors on the lake evolution. Using Multichannel Singular Spectrum Analysis (M-SSA), significant five-year ENSO and 20-year PDO related quasi-oscillations were detected, explaining 54% of the variance associated with mean annual naturalized level fluctuations. ENSO is markedly in-phase with lake levels, with critical declines associated with low precipitation and high evaporation rates during El Ni?o years, whereas the PDO signal exhibits a phase opposition with lake levels, with low naturalized levels during a positive PDO phase and high levels during a negative PDO phase (an important result to consider given the current cooling trend of the PDO signal).