Montane birds experience a range of challenges that may limit their breeding success, including nest predation and severe climactic conditions. The continuing effects of climate change are causing shifts in biotic and abiotic factors that may compound these threats to montane bird species. In northeastern montane forests, many bird species are shifting downslope, potentially as the result of increased precipitation and temperature at higher elevations. Although lower elevations might be more favorable in terms of climactic conditions, nest predation is higher at lower elevations. Thus, montane birds might be faced with the opposing pressures of adverse climactic conditions at higher elevations and increased predation at lower elevations. We monitored nests of Swainson\'s Thrush (Catharus ustulatus) along an elevation gradient in the White Mountain National Forest in New Hampshire in 2016, 2018, 2019, and 2021 to examine the effect of biotic and abiotic factors on daily nest survival rate (DSR). Linear time explained the most variation of DSR in AICc model comparison, indicating that DSR decreases across the breeding season. Rain intensity (mm/h) had a weak negative effect on DSR, indicating that heavier rain per hour decreases Swainson\'s Thrush DSR. Moreover, we found some support for a negative interaction effect of elevation in conjunction with minimum daily temperature: DSR of Swainson\'s Thrush nests at low elevations (281 m) increased with increasing minimum daily temperatures and decreased at high elevations with increasing minimum daily temperatures. Our results suggest nesting survival of montane breeding birds may be at risk as heavier precipitation events become more frequent and intense due to the changing climate and raises the possibility that other passerine species could be at risk in this system.

The Rocky Mountain Biological Laboratory (RMBL; Colorado, USA) is the site for many research projects spanning decades, taxa, and research fields from ecology to evolutionary biology to hydrology and beyond. Climate is the focus of much of this work and provides important context for the rest. There are five major sources of data on climate in the RMBL vicinity, each with unique variables, formats, and temporal coverage. These data sources include (1) RMBL resident billy barr, (2) the National Oceanic and Atmospheric Administration (NOAA), (3) the United States Geological Survey (USGS), (4) the United States Department of Agriculture (USDA), and (5) Oregon State University\'s PRISM Climate Group. Both the NOAA and the USGS have automated meteorological stations in Crested Butte, CO, ~10 km from the RMBL, while the USDA has an automated meteorological station on Snodgrass Mountain, ~2.5 km from the RMBL. Each of these data sets has unique spatial and temporal coverage and formats. Despite the wealth of work on climate-related questions using data from the RMBL, previous researchers have each had to access and format their own climate records, make decisions about handling missing data, and recreate data summaries. Here we provide a single curated climate data set of daily observations covering the years 1975-2022 that blends information from all five sources and includes annotated scripts documenting decisions for handling data. These synthesized climate data will facilitate future research, reduce duplication of effort, and increase our ability to compare results across studies. The data set includes information on precipitation (water and snow), snowmelt date, temperature, wind speed, soil moisture and temperature, and stream flows, all publicly available from a combination of sources. In addition to the formatted raw data, we provide several new variables that are commonly used in ecological analyses, including growing degree days, growing season length, a cold severity index, hard frost days, an index of El Niño-Southern Oscillation, and aridity (standardized precipitation evapotranspiration index). These new variables are calculated from the daily weather records. As appropriate, data are also presented as minima, maxima, means, residuals, and cumulative measures for various time scales including days, months, seasons, and years. The RMBL is a global research hub. Scientists on site at the RMBL come from many countries and produce about 50 peer-reviewed publications each year. Researchers from around the world also routinely use data from the RMBL for synthetic work, and educators around the United States use data from the RMBL for teaching modules. This curated and combined data set will be useful to a wide audience. Along with the synthesized combined data set we include the raw data and the R code for cleaning the raw data and creating the monthly and yearly data sets, which facilitate adding additional years or data using the same standardized protocols. No copyright or proprietary restrictions are associated with using this data set; please cite this data paper when the data are used in publications or scientific events.

Tropical montane bird communities are hypothesized to be highly sensitive to anthropogenic disturbance because species are adapted to a narrow range of environmental conditions and display high rates of endemism. We assessed avian sensitivity at regional and continental scales for a global epicenter of montane bird biodiversity, the tropical Andes. Using data from an intensive field study of cloud forest bird communities across 7 landscapes undergoing agricultural conversion in northern Peru (1800-3100 m, 2016-2017) and a pan-Andean synthesis of forest bird sensitivity, we developed management strategies for maintaining avian biodiversity in tropical countrysides and examined how environmental specialization predicts species-specific sensitivity to disturbance. In Peru, bird communities occupying countryside habitats contained 29-93% fewer species compared with those in forests and were compositionally distinct due to high levels of species turnover. Fragments of mature forest acted as reservoirs for forest bird diversity, especially when large or surrounded by mixed successional vegetation. In high-intensity agricultural plots, an addition of 10 silvopasture trees or 10% more fencerows per hectare increased species richness by 18-20%. Insectivores and frugivores were most sensitive to disturbance: abundance of 40-70% of species declined in early successional vegetation and silvopasture. These results were supported by our synthesis of 816 montane bird species studied across the Andes. At least 25% of the species declined due to all forms of disturbance, and the percentage rose to 60% in agricultural landscapes. The most sensitive species were those with narrow elevational ranges and small global range sizes, insectivores and carnivores, and species with specialized trophic niches. We recommend protecting forest fragments, especially large ones, and increasing connectivity through the maintenance of early successional vegetation and silvopastoral trees that increase avian diversity in pastures. We provide lists of species-specific sensitivities to anthropogenic disturbance to inform conservation status assessments of Andean birds.
Sensibilidad de aves montanas a perturbaciones antropogénicas y estrategias de manejo para su conservación en paisajes agrícolas Resumen Se ha hipotetizado que las comunidades de aves tropicales montanas son sumamente sensibles a la perturbación antropogénica porque las especies están adaptadas a una reducida gama de condiciones ambientales y tienen altas tasas de endemismo. Evaluamos la sensibilidad aviar a escalas regional y continental para un epicentro global de biodiversidad de aves montanas, los Andes tropicales. Utilizando datos de un estudio intensivo de campo de comunidades de aves de bosques nublados en 7 paisajes bajo conversión agrícola en el norte de Perú (1800 - 3100 m, 2016-2017) y una síntesis pan-Andina de sensibilidad de aves de bosque, desarrollamos estrategias de manejo para el mantenimiento de la biodiversidad de aves en campiñas tropicales y examinamos cómo la especialización ambiental predice la sensibilidad de cada especie a la perturbación. Las comunidades de aves ocupando hábitats campestres tropicales en Perú contenían 29 - 93% menos especies en comparación con las de bosques y tuvieron una composición distinta debido a los altos niveles de recambio de especies. Los fragmentos de bosque maduro fungieron como reservorios para la diversidad de aves de bosque, especialmente cuando eran extensos y estaban rodeados por vegetación secundaria mixta. En las parcelas con actividad agrícola intensiva, la adición de 10 árboles silvopastoriles o 10% más de cercos por hectárea incrementó la riqueza de especies en 18 - 20%. Las insectívoras y frugívoras fueron más sensibles a la perturbación: la abundancia de 40 - 70% de especies declinó en la vegetación secundaria temprana y en la silvopastura. Estos resultados fueron sustentados por nuestra síntesis de 816 especies de aves montanas estudiadas en los Andes. Por lo menos 25% de estas especies declinaron debido a todas las formas de perturbación, y el porcentaje incrementó a 60% en paisajes agrícolas. Las especies más sensibles fueron aquellas con rangos altitudinales estrechos y extensiones de distribución pequeñas, las insectívoras y carnívoras y las especies con nichos tróficos especializados. Recomendamos la protección de fragmentos de bosque, especialmente los extensos, y el incremento de la conectividad mediante el mantenimiento de vegetación secundaria temprana y árboles silvopastoriles que incrementan la diversidad de aves en los pastizales. Proporcionamos listas de la sensibilidad de cada especie a la perturbación antropogénica para contribuir a las evaluaciones del estatus de conservación de aves Andinas.

The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species\' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, but detailed data from diverse taxa within a single ecosystem are rare. We collated first sighting and median activity within a high-elevation environment for plants, insects, birds, mammals and an amphibian across 45 years (1975-2020). We related 10 812 phenological events to climate data to determine the relative importance of climate effects on species\' phenologies. We demonstrate significant variation in climate-phenology linkage across taxa in a single ecosystem. Both current and prior climate predicted changes in phenology. Taxa responded to some cues similarly, such as snowmelt date and spring temperatures; other cues affected phenology differently. For example, prior summer precipitation had no effect on most plants, delayed first activity of some insects, but advanced activity of the amphibian, some mammals, and birds. Comparing phenological responses of taxa at a single location, we find that important cues often differ among taxa, suggesting that changes to climate may disrupt synchrony of timing among taxa.

Dust provides an ecologically significant input of nutrients, especially in slowly eroding ecosystems where chemical weathering intensity limits nutrient inputs from underlying bedrock. In addition to nutrient inputs, incoming dust is a vector for dispersing dust-associated microorganisms. While little is known about dust-microbial dispersal, dust deposits may have transformative effects on ecosystems far from where the dust was emitted. Using molecular analyses, we examined spatiotemporal variation in incoming dust microbiomes along an elevational gradient within the Sierra Nevada of California. We sampled throughout two dry seasons and found that dust microbiomes differed by elevation across two summer dry seasons (2014 and 2015), which corresponded to competing droughts in dust source areas. Dust microbial taxa richness decreased with elevation and was inversely proportional to dust heterogeneity. Likewise, dust phosphorus content increased with elevation. At lower elevations, early season dust microbiomes were more diverse than those found later in the year. The relative abundances of microbial groups shifted during the summer dry season. Furthermore, mutualistic fungal diversity increased with elevation, which may have corresponded with the biogeography of their plant hosts. Although dust fungal pathogen diversity was equivalent across elevations, elevation and sampling month interactions for the relative abundance, diversity, and richness of fungal pathogens suggest that these pathogens differed temporally across elevations, with potential implications for humans and wildlife. This study shows that landscape topography and droughts in source locations may alter the composition and diversity of ecologically relevant dust-associated microorganisms.

The biodiversity in mountainous ecosystems is high but is threatened by rapid environmental change. Urbanization and other anthropogenic factors in the mountains can affect land use and spatial fragmentation. Moreover, patterns of habitat are closely related to elevation and have a major effect on montane biodiversity. The aim of this study was to analyze the effects of spatial fragmentation on the vertical distribution pattern of bird diversity by characterizing the structure of the bird community, species diversity, and landscape factors at different altitudes. From 2016 to 2019, this study made a four years of continuous monitoring of the breeding birds. The result indicated that Mount Tai harbored a high bird diversity. Bird richness, abundance, and Shannon-Wiener index decreased with latitude in Mount Tai monotonically. Moreover, the structure of bird communities varied along altitudinal gradients, and some special species were supported in different elevational bands due to the environmental filtering. Road density, number of habitat patches, patch density, and the percentage of forest were significantly related to bird diversity. Sufficient habitat and more patches in the low-mountain belt supported higher bird diversity. The middle-mountain belt and high-mountain belt showed contrasting patterns. Our results highlight the effects of on-going urbanization and human activities on montane biodiversity and emphasize the need for artificial habitats in the mountains to be managed.

The mountains of southern California represent unique, isolated ecosystems that support distinct high-elevation habitats found nowhere else in the area. Analyses of several moisture-dependent species across these sky-islands indicate they exist as locally endemic lineages that occur across these fragmented mountains ranges. The Rubber Boa is a semi-fossorial snake species that is widely distributed in the cooler and more moist ecoregions regions of western North America, including isolated populations across southern California mountain ranges. We developed a genomic and ecological dataset to examine genetic diversity within Rubber Boas and to determine if the endemic Southern Rubber Boa represents a distinct lineage. We quantified current and future habitat suitability under a range of climate change scenarios, and discuss the possible environmental threats facing these unique montane isolates. Our results support four major lineages within Rubber Boas, with genetic breaks that are consistent with biogeographic boundaries observed in other co-distributed, cool-temperature, moisture adapted species. Our data support previous studies that the Southern Rubber Boa is an independent evolutionary unit and now includes multiple locally endemic sky-island populations, restricted to isolated mountain tops and ranges across southern California. Analyses of future habitat suitability indicate that many of these sky-island populations will lose most of their suitable habitat over the next 70 years given predicted increases in drought, rising temperatures, and wildfires. Collectively these data emphasize the critical conservation needs of these montane ecosystems in southern California under current and projected climate change conditions.

Montane meadows are highly productive ecosystems that contain high densities of soil carbon (C) and nitrogen (N). However, anthropogenic disturbances that have led to channel incision and disconnected floodplain hydrology have altered the C balance of many meadows, converting them from net C sinks to net sources of C to the atmosphere. Restoration efforts designed to reconnect floodplain hydrology may slow rates of soil C loss from degraded meadows and restore the conditions for C sequestration and N immobilization, yet questions remain about the long-term impact of such efforts. Here, we used a 22-year meadow restoration chronosequence to measure the decadal impact of hydrologic restoration on aboveground and belowground C and N stocks and concentrations. Increases in herbaceous vegetation biomass preceded changes in soil C stocks, with the largest gains occurring belowground. Root biomass (0-15 cm) increased at a rate of 270.3 g m-2 year-1 and soil C stocks (0-15 cm) increased by 232.9 g C m-2 year-1 across the chronosequence. Increases in soil C concentration (2.99 g C kg-1 year-1 ) were tightly coupled with increases in soil N concentration (0.21 g N kg-1 year-1 ) and soil C:N did not vary with time since restoration. Fourier transform infrared spectroscopy results showed that the fraction of labile aliphatic C-H and carboxylate C-O (COO) compounds in the soil increased with the age of restoration and were positively correlated with soil C and N concentrations. Our results demonstrate that restoration of floodplain hydrology in montane meadows has significant impacts on belowground C and N stocks, soil C and N concentration, and soil C chemistry within the first two decades following restoration.

Forecasting how species will respond phenologically to future changes in climate is a major challenge. Many studies have focused on estimating species- and community-wide phenological sensitivities to climate to make such predictions, but sensitivities may vary within species, which could result in divergent phenological responses to climate change.
We used 743 herbarium specimens of the mountain jewelflower (Streptanthus tortuosus, Brassicaceae) collected over 112 years to investigate whether individuals sampled from relatively warm vs. cool regions differ in their sensitivity to climate and whether this difference has resulted in divergent phenological shifts in response to climate warming.
During the past century, individuals sampled from warm regions exhibited a 20-day advancement in flowering date; individuals in cool regions showed no evidence of a shift. We evaluated two potential drivers of these divergent responses: differences between regions in (1) the degree of phenological sensitivity to climate and (2) the magnitude of climate change experienced by plants, or (3) both. Plants sampled from warm regions were more sensitive to temperature-related variables and were subjected to a greater degree of climate warming than those from cool regions; thus our results suggest that the greater temporal shift in flowering date in warm regions is driven by both of these factors.
Our results are among the first to demonstrate that species exhibited intraspecific variation in sensitivity to climate and that this variation can contribute to divergent responses to climate change. Future studies attempting to forecast temporal shifts in phenology should consider intraspecific variation.

Species with different life histories and communities that vary in their seasonal constraints tend to shift their phenology (seasonal timing) differentially in response to climate warming. We investigate how these variable phenological shifts aggregate to influence phenological overlap within communities. Phenological advancements of later season species and extended durations of early season species may increase phenological overlap, with implications for species\' interactions such as resource competition. We leverage extensive historic (1958-1960) and recent (2006-2015) weekly survey data for communities of grasshoppers along a montane elevation gradient to assess the impact of climate on shifts in the phenology and abundance distributions of species. We then examine how these responses are influenced by the seasonal timing of species and elevation, and how in aggregate they influence degrees of phenological overlap within communities. In warmer years, abundance distributions shift earlier in the season and become broader. Total abundance responds variably among species and we do not detect a significant response across species. Shifts in abundance distributions are not strongly shaped by species\' seasonal timing or sites of variable elevations. The area of phenological overlap increases in warmer years due to shifts in the relative seasonal timing of compared species. Species that overwinter as nymphs increasingly overlap with later season species that advance their phenology. The days of phenological overlap also increase in warm years but the response varies across sites of variable elevation. Our phenological overlap metric based on comparing single events-the dates of peak abundance-does not shift significantly with warming. Phenological shifts are more complex than shifts in single dates such as first occurrence. As abundance distributions shift earlier and become broader in warm years, phenological overlap increases. Our analysis suggests that overall grasshopper abundance is relatively robust to climate and associated phenological shifts but we find that increased overlap can decrease abundance, potentially by strengthening species interactions such as resource competition.