Lice were collected from 579 hummingbirds, representing 49 species, in 19 locations in Brazil, Costa Rica, Honduras, Paraguay and Peru, at elevations 0–3000 m above sea level. The following variables were included in an ecological analysis (1) host species' mean body mass, sexual size dimorphism, sexual dichromatism, migratory behaviour and dominance behaviour; (2) mean elevation, mean and predictability of temperature, mean and predictability of precipitation of the host species' geographic area; (3) prevalence and mean abundance of species of lice as measures of infestation. Ordination methods were applied to evaluate data structure. Since the traits are expressed at different scales (nominal, interval and ratio), a principal component analysis based on d-correlations for the traits and a principal coordinates analysis based on the Gower index for species were applied. Lice or louse eggs were found on 80 (13.8%) birds of 22 species. A total of 267 lice of 4 genera, Trochiloecetes, Trochiliphagus, Myrsidea and Leremenopon, were collected, with a total mean intensity of 4.6. There were positive interactions between migration behaviour and infestation indices, with elevational migrants having a higher prevalence and abundance of lice than resident birds. Further, we found weak negative correlations between host body mass and infestation indices and positive correlations between mean elevation and prevalence and abundance of Trochiliphagus. Thus, formerly unknown differences in the ecological characteristics and infestation measures of Trochiliphagus and Trochiloecetes lice were revealed, which allows a better understanding of these associations and their potential impacts on hummingbirds.

Ferns (Polypodiophyta) are an abundant floral element of the tropics with high sensitivity to environmental conditions and good indicators of overall biodiversity. Here, we set out to identify which geochemical factors determine fern diversity in a low-montane tropical rainforest in Eastern Ecuador. We conducted a field survey of high-spatial resolution completing a comprehensive fern inventory across two elevational ranges, combined with biochemical characterisation of the underlying soils. While α-diversity was negatively correlated with cation exchange capacity (CEC) and with elevation, β-diversity increased with elevation and with geographic distance, as predicted. Our results confirm that ferns have a high sensitivity to both elevational and environmental gradients, where the latter in this study was derived from enhanced aluminium, iron and calcium contents in some of the studied soils. Further monitoring of fern communities could therefore help to better understand and predict how environmental change may impact biodiversity, with a particular focus on threats potentially arising from toxic elements being released in tropical soils through modified soil CEC.

In the ablation zone of glacier habitats, cryoconite holes are known to harbor diverse microbial communities, including unique diatom floras distinct from those of surrounding aquatic and terrestrial systems. Besides descriptive studies, little is known about the diversity of cryoconite diatoms and their response to environmental stressors, particularly in low-latitude glaciers. This paper documents an extremely diversified diatom community in Antisana Glacier (Ecuador), reporting 278 taxa found in 54 surface holes, although with low individual abundances. Contrary to our expectations, assemblage structure did not respond to water physical or chemical characteristics, nor to cryoconite hole morphology, but to elevation. We demonstrate that elevation is a driver of diatom assemblages. Both alpha diversity (measured as Fisher's index) and species richness (corrected for unequal sample sizes) correlated negatively with elevation, suggesting a replacement toward simplified, poorer communities along this gradient. The taxonomic composition also changed significantly, as revealed by multivariate statistics. In summary, cryoconite holes are sites of high taxonomic diversity composed of taxa that are allochthonous in origin.

Mediterranean mountains are biodiversity hotspots where northern species occur surrounded by drier and warmer lowlands. In this context, global warming is pushing these species to higher elevations. This paper assesses whether forest birds have experienced a shift upwards over the elevation gradient in the last 35 years in the Guadarrama Mountains (600–2,400 m asl; central Spain). Alternatively, the paper tests whether the reported shifts are related to changes in forest structure resulting from rural abandonment and/or forest management. To do this, sampling carried out from 1976 to 1980 along the elevation gradient was repeated in 2014–2015. In addition, the habitat preferences of birds were used to test if the elevation shifts were related to changes in forest structure. Results show that the mean range position of birds associated with tree cover shifted downwards, a trend supported by an increase in tree-dependent birds at mid-elevations. These trends suggest that an increase in tree cover has buffered the altitudinal shifts of forest birds predicted by climate warming. Results also suggest that proper forest management may improve the resilience of forest bird communities to the pervasive effects of climate warming.

Fitness is enhanced by determining when to behave prosocially. Elevation, an uplifting emotion elicited by witnessing exemplary prosociality, upregulates prosociality in the presence of prosocial others, as such contexts render prosociality profitable and/or antisociality costly. Prior research examines responses to a single highly prosocial individual. However, the profitability of enhancing prosociality hinges not only on potential interactions with a single actor, but also on the actions of others. Accordingly, information regarding how others respond to the prosocial exemplar may influence elevation elicitation and corresponding changes in prosocial motivation. If others reciprocate the exemplar's prosociality, or pay prosociality forward, this expands opportunities for the observer to profit by increasing prosociality, and thus could enhance elevation elicitation. Conversely, if others exploit the exemplar, this may diminish the profitability of prosociality, as the observer who acts prosocially may similarly be exploited and/or the resources with which the exemplar could reciprocate will be depleted. Conducting three online studies of Americans in which information regarding the responses of others to a prosocial exemplar was manipulated, we find that, against predictions, prosocial responses by the beneficiaries of prosociality generally do not enhance elevation among observers, whereas, consonant with predictions, antisocial responses markedly diminish elevation among observers.

Conserving alpine ecosystems and the plant communities they contain using ex situ conservation requires an understanding of seed longevity. Knowledge of seed longevity may determine the effectiveness of ex situ seed banking for alpine plant conservation, and may provide insight into plant recruitment in situ. We sought to determine the influence of elevation and climatic variables, as well as plant and seed traits, on the seed longevity of 57 species inhabiting a unique biome, (sub-)alpine regions of mainland Australia. Seed longevity was estimated using controlled accelerated ageing tests to determine the time taken for seed viability to fall by 50%. We found that, across the study species, like alpine seeds elsewhere in the world, Australian alpine seeds are relatively short-lived and overall shorter-lived than Australian plants in general. Seed mass and elevation explained most of the variation in seed longevity among the Australian alpine species considered. Species with larger seed mass, and collections made at higher elevations, were found to have relatively short-lived seeds. Phylogeny, however, explained very little of the variation in longevity. Our results suggest that viability testing for Australian alpine seeds in ex situ seed banks should be conducted with shorter intervals than for the non-alpine flora. This study highlights how seed longevity in the Australian Alps is not dictated primarily by evolutionary lineage but rather by a complex combination of environmental variables and intrinsic seed characteristics. Potential implications for conservation ex situ and in situ in the context of climate change are discussed.

Tropical montane forests (TMF) are associated with a widely observed suite of characteristics encompassing forest structure, plant traits and biogeochemistry. With respect to nutrient relations, montane forests are characterized by slow decomposition of organic matter, high investment in below-ground biomass and poor litter quality, relative to tropical lowland forests. However, within TMF there is considerable variation in substrate age, parent material, disturbance and species composition. Here we emphasize that many TMFs are likely to be co-limited by multiple nutrients, and that feedback among soil properties, species traits, microbial communities and environmental conditions drive forest productivity and soil carbon storage. To date, studies of the biogeochemistry of montane forests have been restricted to a few, mostly neotropical, sites and focused mainly on trees while ignoring mycorrhizas, epiphytes and microbial community structure. Incorporating the geographic, environmental and biotic variability in TMF will lead to a greater recognition of plant–soil feedbacks that are critical to understanding constraints on productivity, both under present conditions and under future climate, nitrogen-deposition and land-use scenarios.

In the present study, body length and dispersal ability were examined in carabid beetles (Coleoptera: Carabidae) sampled in the Peruvian Andes along two altitudinal gradients: old-growth forest and anthropogenically disturbed region. Dispersal ability was estimated by the flight-wing condition (i.e. macropterous or brachypterous) and the cuticular length of the flight muscle (medial length of the metasternum). The relationship between body length and altitude for combined gradients varied by tribe; all possible relationships were found: positive; negative; no relationship. At the family level, a negative relationship between altitude and insect body length was found; this was predicted because of a decrease in the diversity of resources, habitat area and primary productivity, and the increase in the unfavourable environment observed at high altitudes. Flight muscle length was also highly variable among tribes; however, for combined gradients, a negative correlation with altitude was found at the family level. Some tribes were either completely macropterous or brachypterous, but at the family level, the percentage of brachyptery increased with altitude. We suggest two hypotheses that may explain the increased incidence of flightlessness observed with increasing altitude: constraints of energy use and reduced need for dispersal potential. At the family level, carabid beetles tended to have a greater body length and decreased brachyptery in disturbed regions compared with old-growth forests. Increased dispersal ability was expected because of the need to find a suitable habitat in disturbed areas. Observed relationships may depend upon which tribes are examined and whether the forest on an altitudinal gradient has been disturbed.

Germination timing is a key transition of life history. It not only links subsequent life-history traits, such as plant height and flowering time, but also provides a link to the previous generation through the influence of the maternal environment. Environmental factors may mediate these key links, and consequences of this process may influence species regeneration and dispersal. However, little is known about how environmental factors mediate these key links. Here, germination timing under high (natural light) and low light treatments was estimated for 476 angiosperm species of the eastern Tibetan Plateau grasslands. Furthermore, we used standard (std) and phylogenetic (phy) comparative methods to test if germination timing was associated with plant height, flowering time and maternal habitats under both light treatments. Germination timing was positively correlated with plant height only in low light in std-methods. Germination timing was associated with onset of flowering in both light treatments in std-methods, but only in low light when using phy-methods. Germination timing was positively correlated with elevation only in low light when using both comparative methods. Germination timing was correlated with water in maternal habitat only in high light when using both comparative methods. Germination timing was associated with light in maternal habitat in both light treatments in std-methods, but only in high light when using phy-methods. In summary, light-dependent associations of germination timing with subsequent life-history traits and maternal habitats may influence the probability of plant species life-cycle completion and influence distribution and dispersal of plant species in natural plant communities.

The availability of spatial data sourced from either field-derived or satellite-based systems has created new opportunities to estimate and/or monitor changes in carbon sequestration rates, climate change impacts or the potential habitat alterations occurring across large landscapes. However, an effort to create models is not standardized, in part, due to different needs and data sources available for the models. For example, data may have different spatial resolutions with varying degrees of complexity in regards to inputs and statistical methods. This study determines effects of 20, 15, 10, five and one km sampling resolutions on detection of changes in net primary productivity (NPP), occupancy selection criteria for areas to be included in the sample and identification of significant variables impacting NPP in Indonesia forests. Production forest designated for selective harvest was used to define the sampling areas. Variances explained by predictive models were similar across cell sizes although relative importance of variables was different. Partial dependence plots were used to search for potential thresholds or tipping points of NPP change as affected by an independent variable such as minimum daytime temperature. Applying different cell occupancy selection rules significantly changed the overall distribution of NPP values. The magnitude of those changes within a cell size varied with changes in cell size. The mean estimated NPP for production forests across Indonesia differed significantly at every sampling resolution and occupancy selection criteria. Lows ranged from 1.107 to 1.121 kg C m−2 yr−1 for the 1-km cell size for the three occupancy selection criteria with highs ranging from 1.245 to 1.189 kg C m−2 yr−1 for the 20-km cell size. The difference in NPP values between these two cell sizes for the three occupancy selection criteria extrapolates to a range in annual biomass of 132 × 106 to 66 × 106 t for the total area of production forests in Indonesia.

In high-altitude summer pastures, horseflies (Diptera: Tabanidae) can be a serious nuisance to livestock, as well as mechanical vectors of animal diseases such as besnoitiosis, an enzootic disease in the Pyrenees. However, the activity of horseflies in mountainous environments is poorly documented. To study the seasonality and distribution of tabanids in the Pyrenees Mountains, a sampling design was set up in two valleys on opposite sides of the mountain, one north-facing and one south-facing, along high-elevation gradients and at different distances from a water body between May and October 2011. The influence of the landscape on species richness and abundance was assessed by taking into account forested and unforested areas in 200 m radii around the trapping sites. Our findings indicated that: (1) The slope, the altitude and the size of unforested patches significantly influenced community composition of tabanids. (2) Altitude had a positive or a negative effect, depending on the species. (3) Species richness and abundance were negatively correlated with large open habitats and positively correlated with patch-shape complexity. (4) Seasonal succession of the most abundant species was observed in both valleys, with a maximum of catches at the beginning of August; however, tabanid activity ended earlier in the southern valley, which was more exposed to sunlight. (5) Philipomyia aprica, Tabanus bromius, Tabanus glaucopis and Hybomitra auripila were active from 9:00 to 19:00 h (GMT+1), with a peak of activity at midday. This paper also discusses the implications of these findings in relation to changes in horsefly distribution and their control in mountainous environments.

Soil seed banks are important to vegetation recruitment, ecosystem functioning and land management. We evaluated composition of 0–5 cm soil seed banks and relationships of seed banks with forest community types (ranging from low-elevation pinyon–juniper to high-elevation bristlecone pine), vegetation cover and environmental variables within a 40,000-ha relatively undisturbed coniferous forest landscape in Nevada, USA. We collected samples from 36 sites and used the emergence method to assay seed banks. Seed density averaged 479 seeds m− 2 across sites and a total of 39 taxa were detected. Most (79%) of these taxa were perennials and 35 of 39 (90%) were native. Moreover, 62% of seed-bank taxa were in the vegetation of mature forests, an uncommon finding in studies of forest soil seed banks. Seed-bank density, species richness and composition did not display strong relationships with forest community types, vegetation cover or environmental variables. Weak relationships likely arose from the relatively uniform seed-bank density among sites, where 50% of sites had seed densities in the range of 106–282 m− 2. Results suggest that while seed banks on this landscape are not large, they provide recruitment potential for some native perennial species of mature, relatively undisturbed communities.

A climate model, based on effects of water availability and temperature, was recently proposed to explain global variation in bat species richness along altitudinal gradients. Yet such studies are sparse in the tropics and near-absent in Africa. Here we present results from an altitudinal study of bat diversity from Mount Mulanje, Malawi. Using ground nets, canopy nets and harp traps, we sampled eight sites across three habitat zones from 630 m to 2010 m asl. We assessed the influence of climatic, geographic and biotic variables on measures of estimated species richness, Fisher's α, and an unbiased index of compositional turnover. We recorded 723 individuals and 30 species along the gradient, revealing a ‘low plateau’ pattern in estimated species richness, peaking at 1220 m, which is congruent with the global climate model. Measures of local habitat structure significantly explained a large degree of variation in species richness and compositional turnover between sites. Fisher's α was further significantly correlated to mean annual relative humidity, suggesting a background climatic influence.

Contrasting ecological conditions may affect the distribution, abundance and impact of parasites and predators throughout the ranges of hosts and prey. Such patterns are evident on the archipelagos of Hawaii and the Galapagos, which vary in their distribution and abundance of avian parasites within and across islands. Previous research has documented higher intensity of parasitic fly larvae (Philornis downsi) in nests of Darwin's finches on elevated islands of the Galapagos. Here we examine P. downsi intensity and predation in 71 nests of Darwin's small ground finch (Geospiza fuliginosa) on Floreana Island. We found significant differences in parasite intensity, nest predation and clutch size between the lowland (0–100 m) and highland (300–400 m) habitats. Lowland finch nests had few P. downsi parasites (mean of 8 per nest), high nest predation (44% of nests) and large clutch size (3.4). Highland finch nests showed the opposite pattern, with many P. downsi parasites (40 per nest), low nest predation (17%) and small clutch size (2.5). This study suggests that the impacts of an introduced parasite are limited by its niche requirements and resource availability within and across islands. Our findings also imply that the vulnerability of bird populations to introduced parasites and predators is linked with variation in life history strategies across habitats.

Terrestrial insectivorous birds in a cloud-forest on the north-western slope of the Peruvian Andes were described in terms of species richness, abundance, density, territory size and biomass. Abundance, density and territory size were also characterized for several understorey insectivores. The three terrestrial insectivore species, all in the genus Grallaria, had 35.25 territories on a 26.2-ha plot, defended territories of (mean ± SD) 1.65 ± 1.34 ha, dwelled at an average density of 4.4 ± 2.7 pairs per 10 ha per species and constituted a biomass of 2470 g per 10 ha. Eight understorey insectivore species had 122.75 territories on the plot, held territories 0.86 ± 0.62 ha in size, and lived at an average density of 5.0 ± 2.7 pairs per 10 ha per species. Six of the 11 species studied each occupied over 50% of the plot. Data on terrestrial insectivores from this study were compared with data from other Neotropical plots to examine how properties of guild structure relate to one another. Increasing densities, smaller territory sizes and higher biomasses appeared to be linked with decreasing species richness and increasing elevation, suggesting consistent patterns of covariance.

A survey of the diurnal raptor community (46 resident species) at five altitudinal levels from 100 to 4600 m was made in Venezuela using 106 1-km2 sample quadrats and then compared with similar censuses (211 plots) in southwestern Colombia and eastern Ecuador. Six habitat types were defined and habitat preferences were measured from every encountered birds and from the association between individual abundances and the coverage of habitat types on plots. The overall species richness steeply declined with elevation in all three countries. The raptor community consisted mostly of tropical species that rapidly decreased in both abundance and frequency of occurrence with elevation. A small set of subtropical-temperate forest specialists partly replaced them at mid-elevation and only two species occurred in the paramo of Venezuela, against 5–7 in the other countries. Although originally the gradients were probably almost completely covered with forest, a large part of the raptor community is now composed of grassland species, three of them extending from the lowlands to the tree line. The relative impoverishment of the Venezuelan community, especially at upper levels, is attributed to a peninsular effect at the narrow extreme northern tip of the Andes and perhaps also to former forest fragmentation. Within some species, different subspecies had discrete altitudinal distributions and interspecific competition may explain differences in the range extension of some species between countries. Today, however, accelerating deforestation may result in a severe decline of forest-interior species and a probable reduction in the altitudinal range of at least some of them. Species naturally associated with forest gaps or edges usually tolerate a high degree of forest fragmentation and degradation but only one of them may become abundant in heavily human-altered woodlands. Few grassland specialists have become more widely distributed in the increasingly deforested landscapes.

The development of metacommunity theory, which suggests that the diversity and composition of communities is influenced by interactions with other communities, has produced new tools for evaluating patterns of community change along environmental gradients. These techniques were used to examine how plant communities changed along elevation gradients in montane tropical forests. Two transects of 0.1-ha vegetation plots were established every 50 m in elevation in the mountains of eastern Puerto Rico. The transects ranged from 300 m to 1000 m asl and 400 m to 900 m. In each plot, all free-standing woody stems greater than 1 cm in diameter at 130 cm in height were marked, measured and identified. Additional data on three similar transects were taken from the literature. The upper or lower boundaries of species ranges were significantly clumped along all five transects. Coherence, a measure of the number of gaps in species distributions, was also significant across all transects, and three transects showed significant, albeit low, nestedness. Four sites had significant species turnover. These results suggest that metacommunity techniques can be useful in searching for patterns of community change present in montane tropical forests.

A growing body of literature shows that benthic communities are hierarchically structured on spatial and temporal scales. In two study locations at Helgoland (North Sea), the northern and the western locations, we: (1) investigated the variation in abundance of specific algae and invertebrates at two spatial scales; and (2) evaluated the relationship between elevation and specific species at these scales. We were also interested in using this information about the spatial pattern of individual algae and invertebrates as well as the patterns of elevation to help develop a monitoring programme of the rocky intertidal. We examined the variation of individual algae and invertebrates by means of a hierarchical nested design. Data were taken from five replicates per plot, with plots located in transects (two transects per location).

At the northern location, the highest variability in cover of most algae and invertebrates occurred at the scale separated by about 50 m (scale: transect). This was a direct result of differences between the high- and the low-shore. Most species at high-shore showed a relatively low frequency of occurrence in contrast to a highest frequency of occurence (~100%) and maximal values of cover at low-shore. However, neither a linear nor a non-linear relationship between elevation and the specific species occurred. At the western location, the highest variability in most macroalgae and invertebrates investigated was among replicates (10s of centimetres apart). No relationship between elevation and individual species occurred at this location. Macroalgae at both locations were more consistent over time than invertebrate species. Our results suggest that the relevant processes shaping the individual macroalgae and invertebrates at the Helgoland rocky intertidal vary between locations and the specific species.

The potential causes of variation in macroalgal and invertebrate species at different spatial scales are discussed and suggestions for a future monitoring programme are given. Temporal inconsistency in the spatial patterns, and the fact that some individual algae and invertebrates comprising the benthic assemblages vary at different scales, speak in favour of a multiple-scale sampling approach for monitoring change in the intertidal communities at Helgoland.