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The Andes mountain range in South America has a high level of endemism and is a major source of ecosystem services. The Andes is increasingly threatened by anthropogenic disturbances that have allowed the establishment of non-native plants, mainly in the lower elevation areas. However, synergies between climate change and anthropogenic pressure are promoting the spread of non-native plants to higher elevation areas. In this article, we evaluate and identify the main non-native plants invading Andean ecosystems, and assess their taxonomic families, growth forms and distribution patterns. Based on a systematic literature review, we identified the importance of climatic and anthropogenic factors as drivers of non-native species establishment in Andean ecosystems and the main impacts of non-native plants in the Andes. We then identified research gaps across each biogeographic region in the Andes. Finally, we highlight key elements to better tackle the problem of non-native plant invasions in Andean ecosystems, including the need for a systematic monitoring of invasion patterns and spread (e.g. MIREN protocol) and a common policy agenda across international borders for the prevention and management of non-native plants in this highly vulnerable region. [ABSTRACT FROM AUTHOR]

Background and aims: In order to contribute to the knowledge and conservation of the arid Andes flora, we explored how vehicular roads and elevation affect the composition and richness of plant communities. In addition, we aim to estimate the degree of plant invasion in the native community and identify the most common non-natives at three protected areas in Mendoza. M&M: We recorded the composition and abundance of native and non-natives along the elevation gradient (from 1700 to 3900 m a.s.l.) in three vehicular roads (Villavicencio, Cordón del Plata, and Manzano-Portillo). At each road, 20 "T-plots" were located according to the MIREN protocol . Results: We identified 357 species, 42 were non-native (12%). Non-native cover was higher at Cordón del Plata (23%) than in the other protected areas (Manzano 11%, Villavicencio 6%). Most non-natives were herbaceous, except Rosa rubiginosa. Of all species, 64% of natives and 45% of non-natives were exclusive to a protected area, therefore native and nonnative species composition was different among the protected areas. Non-native richness was higher near the road and decreased quadratically with elevation, but to explain native richness patterns it was necessary to consider the interaction between elevation and distance from the road. Native richness near the road was constant along the elevation gradient (~15 species) but showed a decreasing linear relationship away from the road. Conclusions: Roads can modify the distribution patterns of species along the elevation in the Andes. [ABSTRACT FROM AUTHOR]

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Aim: Climate change is expected to impact mountain biodiversity by shifting species ranges and the biomes they shape. The extent and regional variation in these impacts are still poorly understood, particularly in the highly biodiverse Andes. Regional syntheses of climate change impacts on vegetation are pivotal to identify and guide research priorities. Here we review current data, knowledge and uncertainties in past, present and future climate change impacts on vegetation in the Andes. Location: Andes. Taxon: Plants. Methods: We (i) conducted a literature review on Andean vegetation responses to past and contemporary climatic change, (ii) analysed future climate projections for different elevations and slope orientations at 19 Andean locations using an ensemble of model outputs from the Coupled Model Intercomparison Project 5, and (iii) calculated changes in the suitable climate envelope area of Andean biomes and compared these results to studies that used species distribution models. Results: Future climatic changes (2040–2070) are projected to be stronger at high‐elevation areas in the tropical Andes (up to 4°C under RCP 8.5), while in the temperate Andes temperature increases are projected to be up to 2°C. Under this worst‐case scenario, temperate deciduous forests and the grasslands/steppes from the Central and Southern Andes are predicted to show the greatest losses of suitable climatic space (30% and 17%–23%, respectively). The high vulnerability of these biomes contrasts with the low attention from researchers modelling Andean species distributions. Critical knowledge gaps include a lack of an Andean wide plant checklist, insufficient density of weather stations at high‐elevation areas, a lack of high‐resolution climatologies that accommodates the Andes' complex topography and climatic processes, insufficient data to model demographic and ecological processes, and low use of palaeo data for distribution modelling. Main conclusions: Climate change is likely to profoundly affect the extent and composition of Andean biomes. Temperate Andean biomes in particular are susceptible to substantial area contractions. There are, however, considerable challenges and uncertainties in modelling species and biome responses and a pressing need for a region‐wide approach to address knowledge gaps and improve understanding and monitoring of climate change impacts in these globally important biomes. [ABSTRACT FROM AUTHOR]

Predicted warmer temperatures and more frequent extreme climatic events in the southern Andes may affect the dynamics of the Patagonian forests. These environmental changes may differentially alter the probability of Nothofagus pumilio establishment across its altitudinal range of distribution. We monitored fruit fall, seedling emergence and survival at altitudinal distribution range of N. pumilio forests in Santa Cruz (49°22′ S—72°56′ W), Argentina. Fruit fall, seedling emergence and survival were tested in relation to drought, based on the SPEI (Standardized Precipitation Evapotranspiration Index), interacting with elevation. Fruit fall was consistently higher at low elevation and the abundance of fruits was not affected by drought intensity. Density of new-born seedlings was ~ 9 to 24 times lower at low- than at high-elevation plots in our first observations (2014 and 2016), characterized by warm-dry climatic conditions in spring-early summers. In contrast, seedling abundance was ~ 1.5 times larger at low elevations during relatively cold-wet growing seasons. Survival probability was explained by the interaction between SPEI and elevation. At low elevation and in dry periods, survival probability was lower (CI 54–72%) than in wet periods (CI 68–84%) but at high elevation similar survival was registered even with positive or negative SPEI values. Our results show interacting effects of elevation and drought on tree establishment at the elevation limits, with positive and negative drought effects at high and low elevations, respectively. Predicted increase of extreme drought events during the XXI century could be detrimental for N. pumilio establishment at dry, low-elevation forests. [ABSTRACT FROM AUTHOR]

Copyright of Estudios Atacameños is the property of Estudios Atacamenos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Instituto Superior de Correlacion Geologica, Serie Correlacion Geologica is the property of Instituto Superior de Correlacion Geologica (INSUGEO-CONICET) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mountain protected areas provide a range of ecosystem services including conserving biodiversity, while often providing recreation and tourism opportunities. Unfortunately, tourists and pack animals used to transport equipment can damage sensitive alpine vegetation particularly when they leave trails. This study assessed the impacts of disturbance from off trail use on alpine vegetation in a popular park in the Andes. The effect of different levels of disturbance as well as abiotic factors on alpine steppe vegetation was assessed using generalized linear models and ordinations in 91 plots (20 m2) in the popular Horcones Valley that is used to access remote areas in Aconcagua Provincial Park in Argentina. Disturbance off trails resulted in declines in the cover of native plants, including the endemic shrub Adesmia aegiceras but increases in the cover of herbs including the non-native Convolvulus arvensis. Increased disturbance was associated with shifts from stress tolerant species to ruderal plants characterized by more acquisitive traits, including shorter plants with greater Specific Leaf Area. The research demonstrates the severity of impacts from off trail trampling including how trampling favours some species with specific traits over others and why it is important to limit off track use in areas of high conservation value. • Low alpine vegetation can be affected by off trail use from visitors and pack animals. • Off trail disturbance resulted in shifts of species dominance. • Ruderal and non-native species with acquisitive traits were favoured by disturbance. • Limiting off trail use is critical to conserve alpine plant biodiversity. [ABSTRACT FROM AUTHOR]

Paleoenvironmental records in the eastern Andes (16–26° S), broadly indicate a gradual trend towards aridity from the Early to the Middle Holocene with certain chronological discrepancies. Even under this adverse climatic scenario, the archaeological record suggests the presence of hunter-gatherers in the southern Argentinian Puna associated with the availability of resources for their subsistence, even during drier than present periods. Herbivore coprolites contain multiple proxies that provide independent records of paleovegetation and paleoenvironments. Among them, plant tissue fragments and pollen grains, offer a powerful and complementary insight on past vegetation changes and their relationship with climatic conditions during the Holocene, particularly in the southern Argentine Puna. Thus, in this work camelid coprolites recovered from the archaeological site Quebrada Seca 3 (QS3) were analyzed using microhistological and palynological techniques to reconstruct the diet of these herbivores but also to infer vegetation and environmental changes from the Early to Middle Holocene (ca. 9600–6100 cal yrs BP) in the southern Argentine Puna (26°S). Results of both records show similar patterns in the percentages and species richness (especially those growing in wetlands) within and between coprolites dating to the Early Holocene (9600-8000 cal yrs BP) which suggest an environmental stability during this period. Around 8000 cal yrs BP, an increased variability in the richness of grasses, shrubs, dwarf shrubs, annual herbs and sedges species shows the gradual establishment of dry conditions, peaking around 6100 cal yrs BP. By this time, variability in the plant content of coprolites reflects seasonality in the assemblages due to the presence/absence of annual herbs either in the pollen or microfragment records. Therefore, it is likely that coprolites were from different animals that were hunted at different times of the year, supporting the evidence that QS3 has been occupied for short intervals of time after 7200 cal yrs BP when environmental conditions were extremely arid. The complementary analysis of the microfragments and pollen records preserved in coprolites provide valuable, complementary and alternative archive for herbivorous diet and for vegetation and environmental reconstructions, reinforcing that multiproxy approaches are necessary to obtain maximum information from coprolite studies. • Microhistological and palynological analysis of coprolites show paleovegetation changes. • Changes in the record were evidenced at ca. 8000 cal yrs BP when dry conditions began. • Palynological record indicate seasonal assemblages at ca. 6100 cal yrs BP. • During the extreme dry period of the Middle Holocene, QS3 was temporarily occupied. • Paleoenvironmental inferences from coprolites improve records at local and regional scales. [ABSTRACT FROM AUTHOR]