Introduction Accelerating forest restoration in systems where natural regeneration is slow or unreliable often requires introducing late-successional tree species earlier than they would naturally establish. This is particularly difficult when soil nutrients are depleted and saplings are exposed to sun, wind, and frost. As pioneer stands mature, the performance of late-successional species may improve through increased canopy cover and enhanced soil conditions. However, limited knowledge of species' ecological requirements hinders decisions about optimal timing, canopy, and soil conditions for planting.Objectives We investigated how pioneer stand age, canopy condition, and fertilization affect the establishment of the late-successional tree Maytenus boaria at a high-mountain forest restoration site in central Argentina. There, M. boaria had suffered severe cold-season dieback when planted alongside pioneer trees.Methods We implemented a fully factorial experimental design with three factors: pioneer stand age (2, 6, and 11 years), canopy condition (under-canopy vs. open), and fertilization (fertilized vs. unfertilized). Each treatment combination was replicated 15 times, resulting in a total of 180 experimental units each consisting of one planted M. boaria sapling. Saplings were monitored over a 15-year period to assess survival, height growth, and dieback.Results Survival was lowest (27%) in open planting locations of the 2-year-old stand, and highest (93%) in under-canopy planting locations of the 11-year-old stand. Fertilization had little effect on survival. Height was greatest in three treatments belonging to the 11-year-old stand: under-canopy-fertilized (168 cm), under-canopy-unfertilized (109 cm), and open-fertilized (117 cm). Dieback was highest in open planting locations and, unexpectedly, in the intermediate-aged stand, and was slightly reduced by fertilization from 42 to 37%.Conclusions The successful establishment of late-successional species such as M. boaria depends on specific conditions. Delaying planting until pioneer stands are around 11 years old and targeting under-canopy planting locations can significantly improve survival and growth.

Livestock exclusion is essential for restoring mountain forests in central Argentina. However, it also promotes tussock growth, potentially increasing competitive relative to facilitative effects on saplings, particularly at intermediate elevations, as predicted by the stress-gradient hypothesis. Additionally, leaf-cutting ants may limit sapling establishment at warmer elevations. We tested the importance of competition and ant pruning in the success of Escallonia cordobensis plantings along an elevational gradient. In a full-factorial experiment, 750 saplings were planted at three elevations (1300, 1800, and 2300 m a.s.l.) under two mowing treatments (mowed and unmowed). Sapling survival, height, winter dieback, and ant pruning were evaluated at 30 months across all elevations and at 90 months at the two higher elevations. Survival increased with elevation (39.3%, 75.9%, and 77.6% at 30 months; 27.2% and 60.8% at 90 months). Sapling height declined with elevation and was slightly greater in unmowed plots at 30 months but not at 90 months, whereas winter dieback showed the opposite pattern. We detected no elevation & times; mowing interaction for survival, height and dieback. Ant pruning was concentrated at low and intermediate elevations, affected 14.6% and 5.3% of saplings in the first two years, reducing their survival and growth. Our results do not support the stress-gradient hypothesis; instead, practitioners should consider that tussocks had a weak net facilitative effect across all elevations at an early stage. In contrast, ant pruning reduced sapling performance at lower elevations, indicating that restoration outcomes are jointly shaped by plant-plant interactions and consumer pressure.

Mountain forests have been extensively degraded by human activities, making their conservation and restoration urgent. In subtropical dry mountain forests, successful planting is conditioned by seasonal temperature and precipitation patterns, their variation with elevation, and interactions with co‐occurring vegetation. We studied the effects of elevation (700 and 1,200 m asl), irrigation (with and without), and co‐occurring herbaceous plant cover on the performance of the native Lithraea molleoides saplings. After 2 years, survival was significantly higher at 1,200 m (32%) than at 700 m (16%), whereas irrigation had no significant effect. Increased herbaceous plant cover significantly enhanced survival at low elevation (from 5 to 20%), but significantly reduced survival at high elevation (from 80 to 20%). Stem growth declined over 2 years due to aerial die‐back in all treatments. Increased herbaceous cover significantly reduced stem growth across both elevation and irrigation treatments, with a stronger and significant effect at 1,200 (−2.91 cm) than at 700 m asl (−1.83 cm). Unexpectedly, at low elevations, freezing temperatures were lower, and the number of freezing days was greater than at high elevations, significantly hindering sapling performance. Our results suggest that freezing stress, rather than water deficit, appears to be a more limiting factor for L. molleoides saplings at low elevation. Microsite selection should consider herbaceous cover, which differentially affects survival and growth at each elevation.

High-mountain forests of subtropical and tropical South America are dominated by Polylepis trees. Forest fragmentation is believed to result from human-caused wildfires, livestock grazing and deforestation. Since the 1900s, management of Polylepis forests has included the establishment of conservation areas. We assessed survival and growth of P. australis trees in central Argentina, examining wildfires and land management effects. We monitored 880 trees over 15 years (2003-2018) in 139 plots distributed across conservation and ranching areas. Tree survival rate was 99.2 % yr-1, net height growth 1.4 cm yr-1, and crown dieback 17 %. Fire affected 16 % of plots in ranching areas and 25 % in conservation areas. Compared to unburned plots, fire damage resulted in a 3 % yr-1 reduction in survival rate, a 4 cm yr-1 reduction in height growth, and a 15 % increase in crown dieback. Land management did not affect survival, growth, or crown dieback when controlling for wildfire incidence. However, survival rate and net growth were 0.3 % and 0.6 cm lower in the conservation areas than in ranching areas when wildfire incidence was considered. Plot tree cover was not linked to survival but was positively associated with net growth, elevation was positively associated with survival and negatively with net growth, and tree height was negatively associated with both survival and growth. No logging evidences were observed. We conclude that wildfires are the primary human-induced impact on P. australis trees; therefore, strengthening fire reduction policies is crucial.

Fire refugia play an important role in post-fire ecosystem recovery because they preserve areas that represent a persistent legacy in the landscape and serve as propagule sources for forest regeneration. Our objective was to identify the pre-fire topographic and land cover conditions that determine the presence and quality of megafire refugia in the mountains of central Argentina. In 208 1-ha field-based plots, we assessed pre-fire topographic and land cover variables along with post-fire vegetation responses two years after the megafires. Based on these assessments, we developed a fire refugia quality index ranging from 0 (no refugia) to 5 (high-quality refugia). Using ordinal logistic regression and a model selection approach, we found that high-quality fire refugia were associated with the more humid east mountain flank and east- and north-facing slopes, as well as with smooth terrain, high topographic positions, greater rock cover, steep slopes, and higher tree-to-grass cover proportions. Our findings highlight the importance of topographic and land cover variables in shaping fire refugia and provide insights into post-fire management and the conservation of biodiversity in mountain ecosystems.

Paleontological studies in the central Andes have uncovered the vulnerability of Polylepis forests to climate shifts, attributed to limited seed dispersal capabilities and the rugged terrain. Given the ecological significance of these forests‐forming species as biodiversity hotspots and carbon sinks, their restoration is imperative for the preservation of endemic species and ecosystem services. At the extreme south of the genus' range, we find Polylepis australis , a forest‐forming tree species endemic to Argentina and uniquely extending beyond the Andes into the Sierras Grandes of the Córdoba province. This study utilizes potential distribution models to help inform on restoration strategies considering projected future climate scenarios. Employing Maxent 3.4.3 with 453 presence locations, we estimated a present potential distribution spanning 13,923 km 2 . Our analysis of future climate projections reveals important poleward contractions alongside minor uphill shifts (20 m above sea level), ultimately resulting in a net habitat loss of 4596 km 2 (34%). This underscores the critical role of climate simulations in identifying species specific priority sites for restoration efforts and also highlighting Polylepis forests susceptibility to both climate change and anthropogenic impacts.

Polylepis forests represent one of the most endangered high mountain ecosystems in South America. Therefore, it is necessary to inform local nurseries of the best soil inoculum to grow healthy and strong P. australis seedlings for forest restoration purposes. Arbuscular mycorrhizal fungi (AMF) affect plant performance and plants respond differently to them. Previous studies show that the best AMF source is from non-degraded P. australis forests. However, inoculum from degraded areas has never been tested. The response of P. australis seedlings to inoculation with soils from four sites differing in livestock-associated forest degradation and the identification of root-colonizing of AMF species were evaluated. Natural soils inoculum was collected within the Sierras Grandes Mountain range in central Argentina and belongs to degraded grassland, degraded P. australis forest, intermediate degraded and non-degraded P. australis forests. The samples were described with regard to AMF diversity, soil characteristics, and mycorrhizal inoculum potential. The AMF species diversity and the soil infectivity were high in the degraded forest. Contrary to our expectations, the most advantageous AMF inoculum for promoting the shoot growth of P. australis seedlings in production facilities was sourced from degraded soils (forest and grassland). Seven AMF species were trapped by P. australis root plants and six of them were found in degraded forest soils. Only two AMF species, Septoglomus constrictum and Gigaspora sp., were found to be restricted to degraded forest. These data suggest that degraded forest soils provide the most effective inoculum for promoting sapling growth in a greenhouse setting.

Fire and elevation affect reproduction of woody species and, therefore, their distribution in the landscape; however, the effect of both factors are often confounded. In addition, plant size may also influence reproduction. Our objective was to investigate the combined effects of fire, elevation and pre-fire size on woody species reproductive potential in a seasonally dry mountain ecosystem. We tested the predictions that fire and elevation impair reproductive potential and that the negative effects of fire are enhanced at high elevation. Our study was carried out in the mountains of central Argentina, from 800 to 1700 m a.s.l. We selected individuals of two dominant resprouting woody species (Vachellia caven and Lithraea molleoides) in burned and comparable unburned areas. We estimated pre-fire size and fire damage level in each tree. We monitored parameters related to reproductive potential during four post-fire fruiting seasons in 185 V. caven and 78 L. molleoides trees. Our main results for V. caven show negative fire effects on most reproductive parameters, and on the expected number of germinable seeds per tree, which was estimated as an integrated parameter. The negative fire effects decreased over time until the fourth post-fire fruiting season, when we detected almost no fire effects. Moreover, the negative fire effects were greatly enhanced with elevation, while pre-fire size showed consistently positive effects on most reproductive parameters. For large trees located at low elevation, fire reduced the number of germinable seeds per tree by a factor of nearly six in the third post-fire fruiting season (from 2020 to 358 seeds), while at high elevation fire reduced germinable seeds by a factor of 15 (from 106 to 7 seeds) for similarly large trees. Small trees had a lower reproductive potential than large trees and the negative effects of fire were smaller but noticeable, and were enhanced by elevation, as in the case of large trees. For L. molleoides we found similar patterns to those of V. caven; however, since few trees produced seeds during the study, we did not compute formal statistics. We conclude that fire reduction should gradually increase reproductive potential, tree density and forest cover at high elevation, even when, according to previous studies, survival is not affected by fire or elevation in the study species.

Anthropogenic disturbances profoundly affect forest ecosystems worldwide. Oil exploitation is one of the major stressors driving the high co-occurrence of different non-native plant species in the Yungas forest of Calilegua National Park, Argentina. Using a dataset of records collected from 2010 to 2020, we evaluated environmental drivers and oil exploitation activity shaping the occurrence and diversity of non-native plant species in 18 study sites.To do so, we first compared species richness and diversity at different levels of anthropogenic disturbance. Then, we used regression models to investigate species-environment relationships. Lastly, a fourth corner analysis was applied to investigate how the interaction between explanatory variables and plant functional traits shapes the occurrence of the studied non-native plant species.We found that oil exploitation activities promoted the diversity of non-native plants in the protected area. Presence of the three most widespread non-native plant species was influenced by the topographic slope and organic matter content. The fourth corner analysis further showed that the positive interaction between plant N-fixation capacity with either close proximity to oil boreholes, a low organic matter content or a high coverage of herbs positively affected the presence of non-native plant species.To our knowledge, this is the first time that trait-environment relationships under a gradient of anthropogenic disturbance were investigated to explain the occurrence and diversity of non-native plant species. Given that abundant non-native plant species have partially overlapping niches in the Yungas transition forests, it is advisable that future restoration actions focus on groups of non-native plants rather than single species. Addi-tionally, non-native plant species of concern, which are able to successfully establish in both disturbed and undisturbed areas require adapted eradication measures.

Forest restoration is a great challenge when saplings are repeatedly pruned by leaf‐cutting ants and pesticides are not permitted. Based on four hypotheses (distance‐dependent foraging, plant repellence, structural complexity, and nutrient content), we predicted that sapling performance increases and ant pruning decreases: (1) away from leaf‐cutting ant nests; (2) in unpalatable or (3) tall vegetation patches; and (4) in non‐fertilized soils. We set up a full factorial field experiment to test the hypotheses; we also monitored sapling performance without and with plastic tree shelters used by practitioners to deter ant pruning. Our results showed predicted sapling survival from 40 to 80% per year for distances to nests ranging from 4 to 223 m, respectively. Ant pruning decreased with increasing distance, with null pruning at distances >121 m. Variation in sapling survival, but not in ant pruning, was also explained by the interaction between vegetation palatability and nutrient condition. Vegetation height did not explain sapling survival or pruning. Plastic tree shelters increased survival by 3.5 times and reduced pruning by half. Height of surviving saplings was not affected by any treatment. Our results show the potential for active forest restoration without the use of tree shelters away from leaf‐cutting ant nests, while tree shelters are a viable option near leaf‐cutting ant nests.

En sistemas con lluvias estacionales, el rendimiento hídrico (caudal de salida del curso de agua relativo al área de la cuenca) en la estación seca depende de las lluvias previas y de la infiltración y la evapotranspiración, procesos que, a su vez, están afectados por las características del paisaje. Nuestro objetivo fue evaluar el efecto de distintas variables de paisaje sobre el rendimiento hídrico y la tasa de recesión (tasa a la que disminuye el caudal) durante la estación seca, en cuencas de alta montaña del centro de la Argentina. Seleccionamos 33 cuencas de 9-61 ha, y durante el final de la estación seca de 2017 medimos semanalmente el caudal en sus puntos de cierre durante siete semanas consecutivas. Para cada cuenca calculamos el rendimiento hídrico (mm/mes) promedio y un índice de recesión (adimensional) como la diferencia normalizada del rendimiento entre las últimas y las primeras fechas. Los paisajes extensamente ocupados por un mosaico de pajonal y roca, con pendiente y rugosidad intermedias, tuvieron los rendimientos hídricos máximos (>5 mm/mes). Por lo contrario, el rendimiento hídrico fue más bajo tanto en los paisajes suaves y cubiertos por vegetación, como en los muy ásperos (muy rugosos, escarpados y rocosos). Por su parte, la recesión fue lenta en los paisajes más ásperos y muy abrupta en los paisajes más suaves. Posiblemente, en los paisajes suaves y vegetados se pierde mucha agua por evapotranspiración, mientras que en los paisajes muy ásperos se pierde mucha agua por escorrentía después de las lluvias. Los paisajes con aspereza intermedia y un mosaico de vegetación y roca serían los que optimizan el almacenamiento, minimizando las pérdidas por evapotranspiración. Por lo tanto, para sostener el rendimiento hídrico es prioritario conservar este tipo de paisajes, evitando la erosión del suelo que genera un aumento de áreas rocosas.

Background Setting large- and medium-sized wild mammal (≥ 2 kg) restoration goals is important due to their role as ecosystem engineers and generalized numeric reductions. However, determining wild mammal restoration goals is very challenging due to difficulties in obtaining data on current mammal density and due to unclear information on what mammal density values should be used as a reference. Here we chose a 154 ha conservation area within one of the last remnants of the mountainous Chaco from central Argentina. We suspected that extensive and unreported defaunation had occurred due to past human pressure and the introduction of non-native mammals. To conduct the analyses, we used a simplified technique that integrates methods used in rangeland and ecological sciences. Results Eight native mammal species including only one herbivore species, and four non-native mammal species including three herbivore species were detected during 6113 camera trap days. We used known cattle densities as estimated by droppings and direct counts, together with the relative abundance indexes obtained from camera trap photos to calculate the densities of the other species, correcting for mammal size. Densities for the least and most abundant native species were 0.2 and 1.33 individuals km −2 , respectively; and for non-native species, 0.03 and 5.00 individuals km −2 , respectively. Native and non-native species represented 0.8% and 99.2%, respectively, of the biomass estimates. Reference values for native herbivore biomass, as estimated from net primary productivity, were 68 times higher than values estimated for the study area (3179 vs. 46.5 kg km −2 ). Conclusions There is an urgent need to increase native mammals, with special emphasis on herbivore biomass and richness, while non-native mammal numbers must be reduced. As cattle are widespread in large portions of the globe and there is a lot of experience estimating their abundances, the ratio method we used extrapolating from cattle to other large- and medium-sized mammals could facilitate estimating mammal restoration goals in other small and defaunated areas, where traditional methods are not feasible when target mammal densities get very low.

Los suelos montanos afectados por la pérdida de bosque, el fuego y la ganadería son más propensos a la erosión y, en consecuencia, a una degradación más rápida que afecta su fertilidad. La degradación del suelo dificulta la restauración del bosque nativo y ocasiona bajas tasas de reclutamiento natural y crecimiento lento en las plantaciones. Para contribuir a una restauración más efectiva del bosque, pusimos a prueba la hipótesis de que en suelos montanos degradados, la adición temprana de fertilizantes mejora la supervivencia y el crecimiento de los plantines en los primeros meses de la plantación. Nuestra especie modelo fue Polylepis australis, una arbórea muy usada en proyectos de restauración en las montañas más altas del centro argentino. En un área en restauración con parches de suelos degradados, aplicamos siete tratamientos: tres dosis de NPK triple 15 (25, 34 y 67 g), tres dosis de urea (10, 20 y 30) y un tratamiento sin fertilizante (control). La supervivencia a los 14 meses de plantados fue del 80% y no estuvo asociada al tratamiento de fertilización. Independientemente de la dosis, los plantines fertilizados con NPK crecieron en promedio 5 veces más que los no fertilizados y más del doble que los fertilizados con urea. El crecimiento de los plantines sin fertilizante y los fertilizados con urea no difirió significativamente. Los resultados sugieren que, para P. australis, hay una deficiencia de nitrógeno (N), fósforo (P) o potasio (K) en los suelos degradados, que —al parecer— se pudo enmendar con cualquiera de las dosis de NPK y no así con la adición de urea (únicamente N). Concluimos que en suelos montanos degradados, adicionar nutrientes en el momento de la plantación puede ser una estrategia efectiva para incrementar la cobertura arbórea en menos tiempo y así reducir la erosión de suelos más rápidamente.

La reintroducción de mamíferos fosoriales coloniales en sitios con madrigueras de uso permanente podría estar limitada por disponibilidad de madrigueras satélite donde refugiarse de los depredadores mientras se alimentan, y por disponibilidad de pastos cortos. A fin de generar información para asistir a la reintroducción de vizcachas (Lagostomus maximus), nos preguntamos: 1) ¿qué madrigueras satélite aceptan en función de su complejidad, el tamaño de la entrada y la distancia a madrigueras de uso permanente?, y 2) ¿cómo es afectada el área de pastoreo por la provisión de madrigueras y el corte de pasto? Realizamos el estudio en las Sierras de Córdoba con 13 vizcachas trasladadas a dos corrales de adaptación equipados con madrigueras permanentes. Cavamos 14 madrigueras satélite de dos tipos: simples con solo un túnel y complejas con túnel y cámara subterránea, todas ubicadas a distancias de 1 a 16 m de los corrales de adaptación. Además, cortamos parte de la vegetación. Por seis meses luego de la liberación evaluamos el grado de ocupación de madrigueras satélite. Además estimamos número de heces, suelo desnudo y altura de la vegetación en transectas de 15 m de largo con origen en las madrigueras más usadas que estaban repartidas en dos sectores. El grado de ocupación fue de 2 y 67% para las madrigueras satélite simples y complejas, respectivamente, y se relacionó negativamente con el tamaño de la entrada a la madriguera compleja. No hubo relación entre el grado de ocupación de la madriguera y la distancia a los corrales. El muestreo en transectas reveló que 91% de las heces contabilizadas estaban a 4 m o menos de las madrigueras más usadas, y que preferían el pasto cortado al no cortado. Concluimos que para aumentar área de pastoreo es conveniente construir madrigueras satélite complejas y cortar el pasto.

El control mecánico se utiliza ampliamente para reducir la invasión de arbustos exóticos; no obstante, en especies que rebrotan, el esfuerzo debe mantenerse hasta que el rebrote sea prácticamente nulo. Un régimen de cortes frecuentes implica un esfuerzo concentrado en menos tiempo, pero debería debilitar a la planta más rápidamente y podría redundar en un menor esfuerzo a largo plazo. En este contexto, nos propusimos determinar la frecuencia de cortes óptima. En las sierras de Córdoba, Argentina, seleccionamos 192 arbustos de Pyracantha angustifolia y P. aff. atalantioides, medimos sus tamaños, los cortamos en la base, aplicamos tres frecuencias de corte del rebrote (anual, bienal y al año 4) y registramos todos los tiempos de corte. Al año 5, la supervivencia fue 36, 83 y 91% para los arbustos cortados anual, bienal y al año 4, respectivamente. La altura promedio precorte fue 323±13 cm, y al año, el rebrote medía casi la mitad en todos los tratamientos. En el tratamiento de cortes anuales, el rebrote fue cada vez menor. En el tratamiento de corte bienal —en los años 2 y 4—, el rebrote alcanzó 84 y 88% de la altura original, respectivamente. En el tratamiento de corte al año 4, el rebrote llegó a una altura de 351±13 cm, superando en 20 cm su altura precorte. El número de frutos para el tratamiento de corte anual y bienal fue 0 y 33 frutos.arbusto-1.año-1, respectivamente, y en el tratamiento de corte al año 4, subió de 0 a 565±85 frutos.arbusto-1.año-1 desde el año 1 al 4. El único tratamiento con una reducción sostenida del tiempo de corte fue el anual. Concluimos que el control mecánico de Pyracantha debe contemplar una estrategia de cortes frecuentes.

In mountain forests, tree regeneration is limited by increasingly frequent frosts with increasing elevation. We investigated the effects of exposure to freezing temperature on early life stages of two native trees of different elevational origin in a seasonally dry mountain forest. We hypothesized that the negative effects of freezing exposure on performance of early life stages increases as freezing temperature decreases, and that frost resistance increases in plants of high elevational origin. We collected seeds of two tree species (Kageneckia lanceolata and Lithraea molleoides) from populations located at different elevations and grew seedlings and saplings in a greenhouse. Dry seeds, imbibed seeds and 1-month-old seedlings were exposed to seven temperature treatments ranging from 4 °C to -20 °C, while 12-month-old saplings were exposed to four temperature treatments from -8 °C to -20 °C. After freezing exposure in a climate chamber, we monitored seed germination and seedling and sapling survival. Germination of K. lanceolata decreased with decreasing temperature only for imbibed seeds from mid- and high elevations, whereas germination of L. molleoides slightly increased with decreasing temperature only for imbibed seeds from high elevations. For both species, seedling survival decreased with decreasing temperature. For K. lanceolata, the negative effects of freezing temperatures were weaker as elevational origin of seeds increased, whereas L. molleoides showed the opposite pattern. For both species, saplings only survived at the mildest applied freezing temperature (-8 °C). We conclude that effects of climatic variation associated with elevation depend on the study species and life stage. The observed patterns could be caused by maternal effects, which are absent at the sapling stage. Moreover, temperatures below -8 °C can limit recruitment since partial mortality of seedlings and saplings occurred at such values.

Determining barriers to tree regeneration along elevational gradients is important to predict shifts in regeneration patterns under climate change scenarios. The stress-gradient hypothesis predicts that facilitation predominates at high elevations and competition at low elevations. Invertebrate herbivory may also play an important, yet hardly recognized role, in low elevation and degraded areas. Our objective was to understand the relative changes in facilitation, competition and invertebrate herbivory along an elevational gradient degraded by long-term livestock rearing and repeated wildfires. Our study area was a seasonally dry ecosystem in central Argentina subjected to forest restoration activities. We planted 3000 saplings of the dominant early and late successional tree species in a full factorial design that included elevation (3 levels: low, 1300; intermediate, 1800; and high, 2300 m a.s.l.), microsite treatment, where we manipulated facilitation and competition (4 levels: tussock grasses mowed to the ground, tussock grasses mowed to 15 cm above the ground, unmowed tussock grasses with an average height of 70 cm, and tussock grasses mowed to the ground near rock outcrops) and 5 blocks per elevation. We monitored sapling survival, change in height, and damage by invertebrate herbivores during one year. For both species, sapling survival significantly increased with elevation, while sapling change in height decreased. Survival and change in height for microsite treatments suggest weak competition for the early successional species and facilitation for the late successional species. Notably, we did not find the elevation and microsite treatment interaction predicted by the stress-gradient hypothesis. The main invertebrate herbivores were leaf-cutting ants, which damaged 42, 33 and 0%, and 25, 27 and 0% of the saplings according to species, for the low, intermediate and high elevations, respectively. Damage did not differ significantly between microsite treatments for either species. Survival for saplings with evidence of damage by leaf-cutting ants was 2.5 and 3.4 times lower as compared saplings with no evidences, according to species. Our findings imply that under a climate warming scenario, future facilitation and competition effects will be similar to current effects, whereas leaf-cutting ants rather than competition may increasingly limit tree regeneration.

Knowing the state of the art on research related to post-mining active revegetation can help to improve revegetation success and identify research gaps. We performed a systematic review about active revegetation after mining and identified 203 relevant studies. Most studies were performed in the USA (34%), in regions with a temperate climate (59%) and in abandoned coal mines (45%). The studies were focused on the plantation of woody species (59%) or sowing of herbaceous species (39%). The most widely evaluated treatments were the addition of amendments (24%) and fertilizers (21%), mainly with positive and neutral effects; in general, organic amendments presented more positive effects than inorganic amendments and fertilizers. We also identified studies on the effects of plowing, inoculation of microorganisms, nurse plants, herbivore exclusion and watering. The results of these treatments should be taken with caution, because they can vary according to the functional strategies of the introduced species and the local context, such as the degree of nutrient limitation in the mining area and abiotic conditions. Further research is needed in non-temperate climates, involving long-term monitoring and with detailed descriptions of the interventions to better interpret results and general implications of active revegetation of mining areas.

Domestic livestock are widespread in seasonally dry forests, likely causing forest degradation and limiting tree seedling establishment. Shrubs can play an important role in facilitating tree regeneration, by protecting trees from livestock damage and ameliorating unfavorable abiotic conditions. We aimed at disentangling the relative contribution of grazing exclusion, long‐term forest conservation, and the potential facilitation effect of shrubs on the performance of saplings of the native tree Kageneckia lanceolata. We planted 400 saplings in grazed and ungrazed areas situated both in a preserved and a degraded forest. In each situation, we established planting plots in three accompanying vegetation treatments: herbs, a nonleguminous spiny shrub and a leguminous spiny shrub. Survival of 3‐year‐old saplings was 10‐fold higher in the preserved than in the degraded forest and 2‐fold higher in the ungrazed than in the grazed site. Differences in survival among accompanying vegetation treatments were much smaller than between grazing treatments. Survival significantly increased with increasing protection by shrubs only in the degraded site. Sapling growth patterns were fairly similar to survival patterns, with no growth in the degraded forest, except for limited growth under both shrubs in the ungrazed site. We conclude that, in selecting plantation sites for the study species, forest condition and grazing exclusion should be prioritized over microsite selection based on neighboring vegetation.

Polylepis is the dominant genus of the high Andean forest vegetation and they have a crucial ecological role. However, these forests are highly endangered and many of their biological aspects are still unknown. In this context, a series of questions were formulated with the aim that their resolution would contribute to a better understanding of Polylepis'dynamics and biological diversity, as well as improve their conservation efforts. Twenty one speakers from the V International Congress of Conservation and Ecology of Polylepis forests participated in the formulation of 67 questions related to these forests. Comments and additional information were received via email and google doc spreadsheet, open to the participants. Afterwards, two workshops were organized with the researchers to formulate, discuss, analyze and define the final list, narrowing down to a total of 40 questions. The questions were categorized into 6 different topics: Taxonomy, Ecology and Biogeography, Genetics, Conservation, Ethnobiology and Climate Change. We hope these questions will be considered as a priority for new research agendas and to define joint efforts for Polylepis forest conservation.