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PREMISE: Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700-2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200-1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. METHODS: Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait-niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). RESULTS: For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34-0.58) than plantings (MD 0.50-0.70) for both species. CONCLUSIONS: Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions.

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We present the results of herpetological surveys in two adjacent mountains where the EcoMinga Foundation protects the cloud forest in the Upper Rio Pastaza watershed, in the Llanganates Sangay Ecological Corridor in Ecuador. A rapid assessment of the amphibian communities of the study sites reveals a diverse and heterogeneous composition, dominated by terrestrial frogs from the genus Pristimantis. We also identify a cryptic diversity with a significant number of candidate new species. We describe two new species of terrestrial frogs of the genus Pristimantis. Pristimantismaryanneae sp. nov. is characterised by not having tympanum externally visible and having 2-3 subconical tubercles in the upper eyelid; and Pristimantisburtoniorum sp. nov. is characterised by the presence of red colouration in hidden surfaces of the hind-limbs, tubercles on the upper eyelid, interorbital tubercle and a row of rounded tubercles along the snout to the tip and a pale red venter with dark brown mottled pattern. Our samples from the two Reserves do not share species between them, so the proportion of shared species seems to be relatively low. In addition, we highlight the importance of updating the knowledge of amphibians that are restricted to this important conservation region and comment about the threats and composition of the amphibian communities on the eastern slopes of the Upper Rio Pastaza watershed.

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The montane cloud forests of the Sierra Madre de Oaxaca (SMO) host a remarkable herpetofauna diversity and represent one of the most important areas of endemism for Mexico and Mesoamerica. Although the area has been previously studied, most of the extant records for this group are biased to locations accessed by paved roads. In addition, an important proportion of this territory is conserved by Indigenous and Community Conservation Areas (ICCA), but little information of the species occurring within these areas exists. Therefore, information on the distribution of many endemic taxa in this region to date is either underestimated or incomplete. With the aim of increasing the ecological and distributional knowledge of this group in remote areas, we carried out field surveys in Santa Cruz Tepetotutla Oaxaca, a locality 25 km in a straight line to the closest paved road that conserves 9,670 ha of land through the ICCAs modality. Surveys were made during 2018 and 2019, including both dry and wet seasons. A total of 40 species of amphibians and reptiles were recorded: 32.5% of these records represent distributional range extensions, while 20% represent altitudinal range extensions. A total of 17.5% are records of species under a high risk category, highlighting both the relevance of studying remote areas to increase species population knowledge and the role of community conservation actions for species persistence. Finally, our records include the rediscovery of Rhadinella schistosa, a species undetected for more than 50 years.

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Four new species of the spider genus Novalena Chamberlin Ivie, 1942 are described: N. bola sp. nov., N. mayae sp. nov., N. padillai sp. nov., and N. zootaxa sp. nov. All species were collected in montane forests in Chiapas, Mexico, and three of them occur in sympatry across their distribution range.

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Liverworts and mosses are a major component of the epiphyte flora of tropical montane forest ecosystems. Canopy access was used to analyse the distribution and vertical stratification of bryophyte epiphytes within tree crowns at nine forest sites across a 3400 m elevational gradient in Peru, from the Amazonian basin to the high Andes. The stable isotope compositions of bryophyte organic material (13C/12C and 18O/16O) are associated with surface water diffusive limitations and, along with C/N content, provide a generic index for the extent of cloud immersion. From lowland to cloud forest δ13C increased from -33‰ to -27‰, while δ18O increased from 16.3‰ to 18.0‰. Epiphytic bryophyte and associated canopy soil biomass in the cloud immersion zone was estimated at up to 45 t dry mass ha-1, and overall water holding capacity was equivalent to a 20 mm precipitation event. The study emphasizes the importance of diverse bryophyte communities in sequestering carbon in threatened habitats, with stable isotope analysis allowing future elevational shifts in the cloud base associated with changes in climate to be tracked.

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Bat communities' responses to land use change in neotropical montane forests have scarcely been studied. We hypothesized that, like in lowland forests, a montane agricultural area will have a lower species richness, abundance, diversity and species composition of understory phyllostomid bats than a native forest (montane cloud forest and pine-oak forest). Monthly surveys over the course of a year gave an overall low species richness and abundance (167 captures corresponding to nine species). We found a slight loss of species richness in agricultural areas with respect to the montane cloud forest (one species) and pine-oak forest (two species). However, differences in abundance were noteworthy: 45% and 73% fewer captures in agricultural areas than in the montane cloud forest and pine-oak forest, respectively. Species diversity was higher in the montane cloud forest than the pine-oak forest, but the diversity of agricultural areas did not differ between the types. Species and guild compositions did not differ between crops and forests. At least for the understory phyllostomid bats, and at the spatial scale studied, traditional management of agricultural areas in the study area and the surrounding matrix could explain the similarity in species richness, composition, and diversity between the agricultural area and native montane forests; however, other indicator groups should be evaluated to understand the effects of habitat loss on montane forests.

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Charadrahyla esperancensis, a new species of tree frog, is described from the cloud forest of Sierra d Juárez on the northern slopes of Oaxaca. This species is sympatric with C. nephila and is distinguished by the presence of a protuding snout with a distinctive downward slope posterior to the nostril in lateral view, with an evident rostral keel, and the flanks and anterior and posterior surfaces of limbs with yellow spots. With the discovery of this new species, the species number of the genus increases to seven and adds another species of Charadrahyla for the assemblage of anurans from northern Oaxaca. This is the first instance of sympatry of species in the genus Charadrahyla. Additionally, we provide a key to the species of the genus.

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Secondary forests and coffee agroecosystems are considered good alternatives for conservation of a high capacity for water filtration in the soil where tropical montane cloud forests (TMCF) once grew; however, it is not clear which characteristics of the vegetation modulate the field saturated hydraulic conductivity of the soil (Kfs) and whether these characteristics persist in such derived systems. Here, we explore how changes in vegetation between secondary forests and coffee agroecosystems have consequences for the average value and spatial variation of litter thickness and root biomass, and whether these differences can explain the Kfs and its spatial distribution. We found that the thickest litter, greatest total biomass and thickest roots are in the secondary forest of the north of the study area. The litter is spatially structured in patches of ca. 12m at plot scale in the secondary forest and coffee agroecosystem of the southern area. Like the Kfs, the thickness of the litter and biomass of the thick (>2mm), medium (1-2mm) and fine (<1mm) roots are spatially distributed on a north to south gradient at landscape scale. Our linear model indicates that geographic area (north or south), land use and litter thickness explain the Kfs and its spatial distribution along this gradient. Even on inclusion of the antecedent soil moisture and percentage of clays (found to explain Kfs in a previous study), it was not possible to eliminate from the model geographic area and land use, due to their high explanatory power. However, antecedent soil moisture became redundant on inclusion of the litter layer, which had a greater explanatory power. Our modeling suggests that undiscovered differences prevail between the geographic areas and secondary forest and coffee agroecosystems (possibly related to the edaphogenesis and management practices) that determine the Kfs.

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Many tropical montane cloud forest (TMCF) trees are capable of foliar water uptake (FWU) during leaf-wetting events. In this study, we tested the hypothesis that maintenance of leaf turgor during periods of fog exposure and soil drought is related to species' FWU capacity. We conducted several experiments using apoplastic tracers, deuterium labeling and leaf immersion in water to evaluate differences in FWU among three common TMCF tree species. We also measured the effect of regular fog exposure on the leaf water potential of plants subjected to soil drought and used these data to model species' response to long-term drought. All species were able to absorb water through their leaf cuticles and/or trichomes, although the capacity to do so differed between species. During the drought experiment, the species with higher FWU capacity maintained leaf turgor for a longer period when exposed to fog, whereas the species with lower FWU exerted tighter stomatal regulation to maintain leaf turgor. Model results suggest that without fog, species with high FWU are more likely to lose turgor during seasonal droughts. We show that leaf-wetting events are essential for trees with high FWU, which tend to be more anisohydric, maintaining leaf turgor during seasonal droughts.

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The global increase in demand for productive land requires us to increase our knowledge of the value of agricultural landscapes for the management and conservation of biodiversity, particularly in tropical regions. Thus, comparative studies of how different community attributes respond to changes in land use under different levels of deforestation intensity would be useful. We analyzed patterns of dung beetle diversity in an Andean region dominated by sun-grown coffee. Diversity was estimated using two measures of species abundance (the number of individuals and biomass) and was compared among four types of vegetation cover (forest, riparian forest, sun-grown coffee, and pastures) in three landscape plots with different degrees of deforestation intensity (low, intermediate, and high). We found that dung beetle diversity patterns differed between types of vegetation cover and degree of deforestation, depending on whether the number of individuals or biomass was used. Based on biomass, inequality in the dung beetle community was lowest in the forest, and increased in the sun-grown coffee and pastures across all levels of deforestation, particularly for the increasing dominance of large species. The number of beetles and biomass indicate that the spatial dominance of sun-grown coffee does not necessarily imply the drastic impoverishment of dung beetle diversity. In fact, for these beetles, it would seem that the landscape studied has not yet crossed "a point of no return." This system offers a starting point for exploring biodiversity management and conservation options in the sun-grown coffee landscapes of the Colombian Andes.

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Riparian remnants are linear strips of vegetation immediately adjacent to rivers that may act as refuges for biodiversity, depending on their habitat quality. In this study, we evaluated the role of riparian remnants in contributing to the diversity of leaf-litter ants by determining the relationship between ant diversity and several riparian habitat characteristics within a human-dominated landscape in Veracruz, Mexico. Sampling was carried out in 2012 during both dry and rainy seasons at 12 transects 100 m in length, where 10 leaf-litter samples were collected along each transect and processed with Berlese-Tullgren funnels and Winkler sacks. A total of 8,684 individuals belonging to 53 species, 22 genera, and seven subfamilies were collected. The observed mean alpha diversity accounted for 34.4% of the total species recorded and beta diversity for 65.6%. Species richness and composition were significantly related to litter-layer depth and soil compaction, which could limit the distribution of ant species depending on their nesting, feeding, and foraging habits. Riparian remnants can contribute toward the conservation of ant assemblages and likely other invertebrate communities that are threatened by anthropogenic pressures. In human-dominated landscapes where remnants of riparian vegetation give refuge to a diverse array of myrmecofauna, the protection of the few remaining and well-preserved riparian sites is essential for the long-term maintenance of biodiversity.

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Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.

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BACKGROUND: Tropical montane cloud forests (TMCFs) are characterized by a unique set of biological and hydroclimatic features, including frequent and/or persistent fog, cool temperatures, and high biodiversity and endemism. These forests are one of the most vulnerable ecosystems to climate change given their small geographic range, high endemism and dependence on a rare microclimatic envelope. The frequency of atmospheric water deficits for some TMCFs is likely to increase in the future, but the consequences for the integrity and distribution of these ecosystems are uncertain. In order to investigate plant and ecosystem responses to climate change, we need to know how TMCF species function in response to current climate, which factors shape function and ecology most and how these will change into the future. SCOPE: This review focuses on recent advances in ecophysiological research of TMCF plants to establish a link between TMCF hydrometeorological conditions and vegetation distribution, functioning and survival. The hydraulic characteristics of TMCF trees are discussed, together with the prevalence and ecological consequences of foliar uptake of fog water (FWU) in TMCFs, a key process that allows efficient acquisition of water during cloud immersion periods, minimizing water deficits and favouring survival of species prone to drought-induced hydraulic failure. CONCLUSIONS: Fog occurrence is the single most important microclimatic feature affecting the distribution and function of TMCF plants. Plants in TMCFs are very vulnerable to drought (possessing a small hydraulic safety margin), and the presence of fog and FWU minimizes the occurrence of tree water deficits and thus favours the survival of TMCF trees where such deficits may occur. Characterizing the interplay between microclimatic dynamics and plant water relations is key to foster more realistic projections about climate change effects on TMCF functioning and distribution.

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Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis is an endangered pioneer key species for tropical montane cloud forest regeneration in Mesoamerica. Human activities have severely reduced some P. chiapensis populations, which exhibited a small or null colonization potential suggesting the involvement of genetic factors associated with small populations. We explored the relationships between (i) population genetic diversity (allozymes) and population size, including sampling size effects, (ii) fitness estimates associated with colonization potential (seed viability and seedling performance) in a common environment and population size, and (iii) fitness estimates and observed heterozygosity in populations with sizes spanning five orders of magnitude. All the estimates of genetic diversity and fitness increased significantly with population size. Low fitness was detected in progenies of small populations of disturbed and undisturbed habitats. Progenies with the lowest observed heterozygosity displayed the lowest fitness estimates, which, in turn, increased with heterozygosity, but seed viability peaked at intermediate heterozygosity values suggesting inbreeding and outbreeding depression. Inbreeding depression appears to be the most immediate genetic factor in population decline. Conservation efforts should try to maintain large and genetically diverse populations, enhance gene flow by restoring connectivity between adjacent populations, and avoid genetically distant individuals.

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A Floresta Ombrófila Densa Altomontana é uma formação responsável por importantes funções ambientais, entre elas a proteção e manutenção dos fluxos hídricos de cabeceiras de bacias hidrográficas, o estoque de carbono na sua biomassa e na do solo, além da sua biodiversidade e seu elevado endemismo. Apesar de ainda existirem remanescentes primários significativos dessas florestas, apenas alguns estudos descreveram sua estrutura arbórea. O presente trabalho tem o objetivo de listar e comparar a florística vascular de quatro serras representativas da Floresta Ombrófila Densa Altomontana no Paraná e de comparar a florística arbórea das florestas do presente estudo com a de outras florestas semelhantes nas regiões sul e sudeste do Brasil. Foram detectadas 346 espécies vegetais vasculares, pertencentes a 176 gêneros e a 87 famílias, sendo 72 angiospermas (288 espécies), 14 pteridófitas (57 espécies) e 1 gimnosperma. A família com maior riqueza específica foi Myrtaceae, com 34 espécies (10 por cento do total), seguida por Asteraceae (30; 9 por cento), Orchidaceae (29; 8 por cento), Rubiaceae (17; 5 por cento), Melastomataceae (16; 5 por cento), Poaceae (12; 3 por cento) e Bromeliaceae (11; 3 por cento). A composição florística arbórea das florestas altomontanas da Serra do Mar paranaense apresentou a menor similaridade entre as três grandes serras comparadas, com índices um pouco maiores com as florestas altomontanas da região de Aparados da Serra Geral (SC) e menores com a Serra da Mantiqueira, sudeste do Brasil (SP, RJ e MG). Além de diferenças geológicas, geomorfológicas, pedológicas e fitofisionômicas, as diferenças florísticas encontradas nas florestas altomontanas da Serra do Mar do Paraná em relação às demais serras comparadas pode também ser explicada pela melhor conservação dos trechos amostrados e pela baixa influência de elementos de outros tipos vegetacionais próximos (Floresta Ombrófila Mista, Floresta Ombrófila Densa Montana e vegetação ...

The Cloud Forests have very important environmental functions, among them, the maintenance and protection of the origin of the watersheds and the carbon stocks in its biomass and into the soil, besides its biodiversity and endemism. Despite still exist considerable remnants of primary cloud forests there are few studies that listed species that occur in these ecosystems. The aim of this study was to characterize the floristic composition of four areas of the Upper Montane Rain Forest of the "Serra do Mar" in the state of Paraná and to compare it with other cloud forests in southern and southeastern Brazil. A total of 346 vascular species were detected. They comprised 87 families including 72 angiosperms (288 species), 14 pteridophytes (57 species) and one gymnosperm. The species richest families were Myrtaceae (34 species; 10 percent of total), Asteraceae (30; 9 percent), Orchidaceae (29; 8 percent), Rubiaceae (17; 5 percent), Melastomataceae (16; 5 percent), Poaceae (12; 3 percent) and Bromeliaceae (11; 3 percent). The Serra do Ibitiraquire presented the largest area of cloud forests and the highest species richness (231 species). Of the 346 species found in typical cloud forests, 231 species were classified as typical, 41 as transitionals from high altitude grasslands and 68 as transitionals from lower montane forests. Similarities between the studied areas and other Brazilian cloud forests were low (cluster analyses and Sõrensen indexes). Besides the geological, geomorphological, pedological and forest structural differences, the conservation status, the lower influence of "Mixed Ombrophyllous forests" (Araucaria Moist forests) species, pioneer and lower montane species, justify this lower similarity.

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