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We assessed the impact of road disturbances on the dominant mycorrhizal types in ecosystems at the global level and how this mechanism can potentially lead to lasting plant community changes. We used a database of coordinated plant community surveys following mountain roads from 894 plots in 11 mountain regions across the globe in combination with an existing database of mycorrhizal–plant associations in order to approximate the relative abundance of mycorrhizal types in natural and disturbed environments. Our findings show that roadside disturbance promotes the cover of plants associated with arbuscular mycorrhizal (AM) fungi. This effect is especially strong in colder mountain environments and in mountain regions where plant communities are dominated by ectomycorrhizal (EcM) or ericoid‐mycorrhizal (ErM) associations. Furthermore, non‐native plant species, which we confirmed to be mostly AM plants, are more successful in environments dominated by AM associations. These biogeographical patterns suggest that changes in mycorrhizal types could be a crucial factor in the worldwide impact of anthropogenic disturbances on mountain ecosystems. Indeed, roadsides foster AM‐dominated systems, where AM‐fungi might aid AM‐associated plant species while potentially reducing the biotic resistance against invasive non‐native species, often also associated with AM networks. Restoration efforts in mountain ecosystems will have to contend with changes in the fundamental make‐up of EcM‐ and ErM plant communities induced by roadside disturbance. [ABSTRACT FROM AUTHOR]

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]

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Copyright of Boletín de la Sociedad Argentina de Botánica is the property of Sociedad Argentina de Botanica 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.)

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]

Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non‐native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non‐native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region‐specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non‐native species richness. Non‐native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented. [ABSTRACT FROM AUTHOR]

Background:Damage to alpine plant communities is likely to occur when hikers and pack animals trample vegetation. Currently, there is limited research that quantifies and compares impacts from these activities. Aims:A manipulative experimental protocol was used to assess damage to alpine meadows by pack animals and hikers in the Aconcagua Provincial Park, Andes, Argentina. Methods:Vegetation height, overall cover, cover of dominant species and species richness were measured immediately after, and 2 weeks after different numbers of passes (0, 25, 100 and 300) by hikers or pack animals in an experiment, using a randomised block design. Results:Pack animals had two to three times the impact of hiking on the meadows, with greater reductions in plant height, the cover of one of the dominant sedges and declines in overall vegetation cover after 300 passes. Impacts of pack animals were also apparent at lower levels of use than for hikers. These differences occurred despite the meadow community having relatively high resistance to trampling due to the traits of one of the dominant sedges (Carex gayana). Conclusions:Pack animals caused more damage than hikers to the alpine meadow, but the scale of the difference in short-term impacts depends on the characteristics of the plant community, the amount of use and the vegetation parameters measured. Use of the meadows by hikers and pack animals should be minimised as these meadows are scarce, and have high conservation values. [ABSTRACT FROM AUTHOR]

Although mountain regions are thought to be at lower risk of plant invasions, the diversity and cover of non-native plants is increasing in many alpine ecosystems, including the Andes. We reviewed vegetation surveys in Aconcagua Provincial Park in the dry Andes of Argentina to determine what non-native plants occur in the park and if their distribution is associated with tourism use. This high-altitude park is a popular tourism destination for hikers, with nearly all access by foot and pack animals (mules and horses) that are used for transport. Non-native plant diversity was low (21 species in the region, 16 species in the park) compared to some other mountain regions but included common mountain species from Europe, most of which can be dispersed by tourists and commercial operators on clothing and by pack animal dung. Nearly all non-native plants were restricted to lower altitudes, with no non-natives found above 3420 masl. Most non-native plants were restricted to sites disturbed by tourism use, particularly areas trampled by hikers and pack animals, except for 2 common non-native species, Taraxacum officinale and Convolvulus arvensis, which were also found in undisturbed vegetation. The relatively low cover and diversity of non-native plants at higher-altitude sites may reflect one or a combination of the following: climatic barriers, less human disturbance, and a lag in the dispersal of non-native species from lower altitudes within the park. This study highlights that even protected mountain areas with limited prior human use and nearly no road access can be invaded by non-native plants because of their popularity as mountaineer destinations. Management actions that could help minimize the further spread of non-native plants include limiting the introduction of non-native seeds on vehicles, clothing, and equipment and in dung; reducing trampling damage by restricting visitor use to designated trails; and restoring damaged sites. [ABSTRACT FROM AUTHOR]

The increase use of Off-Road Vehicles (ORVs) coupled with the absence of control strategies have led to extensive use of natural areas for the creation of recreational trails. We assessed the effects of quad bikes on vegetation and soils in an arid ecosystem subjected to intensive quad bike use. We selected randomly eight traffic sites (disturbed sites) and eight adjacent control sites (undisturbed sites). Plant cover and composition were assessed with the point-intercept method and phytosociological census. In each site, we collected soil samples to assess soil physicochemical properties, including apparent specific weight (ASG), actual specific weight (RSG), porosity, texture, electric conductivity (EC) and pH. Soil compaction was measured at 30 spaces points per site. Plant cover and richness was significant lower in disturbed sites, with only four species present in areas subjected to disturbance. There were also changes in species dominance, with native perennial shrubs and grasses characterizing the undisturbed sites while the disturbed sites were mainly dominated by the invasive exotic herb Salsola kali. ORVs traffic also affected soil physicochemical properties including soil compaction, ASG, EC and soil pH. Soil compaction was more than double in disturbed sites and ASG tended to be higher under this condition. The EC was significantly higher and soil pH was significantly lower in the disturbed sites. Reduced vegetation cover and changes to soils physicochemical properties on quadbike trails highlights the impacts of ORVs in the landscape and the need to develop management strategies to minimize disturbance from ORVs on vegetation and soils. • The use of ORVs in the Monte Desert ecosystem damaged vegetation and affected soil health. • Disturbance from ORVs included reduced plant cover and diversity and changes in soil physical properties. • Land managers should limit the spread of informal circuits from ORVs, monitor resource conditions and restore damaged areas. [ABSTRACT FROM AUTHOR]