Tropical Cloud Forest Research Articles

First record of the bryophilous fungi Paruephaedria heimerlii (Dactylosporaceae, Ascomycota) for Mexico

Background and Aims: The briofilous fungi are a diverse and polyphyletic group of symbiotic mushrooms associated specifically with few bryophyte species, genera or families. Paruephaedria heimerlii stands out as a species with a bryophilous habit in Jungermanniales; it is known from Alaska, Europe, Japan and Tasmania. Therefore, the objective of this work is to present the first record of this species in Mexico, its first known tropical locality.Methods: The studied specimens were collected in the vegetation of pine-oak forest and tropical cloud forest in the state of Veracruz, Mexico. The material was herborized and decontaminated by cooling, followed by determination from histological sections of the ascomas and observed with an optical microscope. Finally, the material was deposited in the fungal collections of the herbaria ENCB of the Instituto Politécnico Nacional and XALU of the Facultad de Biología of the Universidad Veracruzana.Key results: Using morphological characteristics and measures of sexual structures like spores, asci and hymenial structures, the studied material was determined as Paruephaedria heimerlii, representing the first record of this species both in Mexico and for the tropics. Conclusions: According to our observations and comparisons with reports in literature, it is probable that the presence of P. heimerlii is not conditioned to the temperature or altitude of the habitat in which it is found, but to the availability of hosts.

Effects of Plant Fine Root Functional Traits and Soil Nutrients on the Diversity of Rhizosphere Microbial Communities in Tropical Cloud Forests in a Dry Season

The composition and diversity of rhizosphere microbial communities may be due to root–soil–microbial interactions. The fine root functional traits and rhizosphere soil environmental factors of 13 representative plants in the Bawangling tropical cloud forest of Hainan Island were measured, to assess the key factors driving plant rhizosphere microbial communities. Illumina MiSeq sequencing technology was used to sequence the v3-V4 region of the 16SrDNA gene of 13 plant rhizosphere soil bacteria and the ITS1 region of the fungal ITSrDNA gene. Results showed that there were 355 families, 638 genera, and 719 species of rhizosphere soil bacteria as well as 29 families, 31 genera, and 31 species of rhizosphere soil fungi in the tropical cloud forests. The fine root traits, such as root phosphorus content, the specific root length and specific root area, were significantly negatively correlated with the Faith-pd indices of the bacterial community but were not correlated with the diversity of fungi communities. The soil pH was significantly and positively correlated with the Chao1 index, OTUs, Faith-pd and Simpson indices of the bacteria and fungi communities. The soil available phosphorus content was significantly and negatively correlated with the bacteria Simpson and the fungus Faith-pd indices. ABT analysis showed that soil pH and soil available phosphorus were the most important environmental conditions contributing to the rhizosphere bacterial and fungi communities, respectively. Our findings demonstrate that the soil environments had more influence on rhizosphere soil microbial diversity than the fine root functional traits.

Characteristics of Central American brocket deer resting sites in a tropical mountain cloud forest in eastern Mexico.

The Central American brocket deer is a vulnerable species. Geographically isolated populations have been affected by poaching and habitat fragmentation, leading to local extinctions. It is therefore important to understand this species’ habitat characteristics, particularly of resting sites, which play a crucial role in survival and fitness. We describe the characteristics and distribution patterns of Central American brocket deer resting sites at the microhabitat and landscape scales in San Bartolo Tutotepec, Hidalgo, México. We conducted eight bimonthly field surveys between November 2017 and March 2019, consisting of 32 transects of 500 m length to search for fecal pellets, footprints, scrapes, and browsed plants. At each resting site we identified, we measured canopy closure, horizontal thermal cover, protection from predators for fawns and adults, escape routes, slope from the ground, presence of scrapes, cumulative importance value of the edible plant species, and distance from the resting site to the nearest water resource to characterize the site at the microhabitat scale. At the landscape scale, we identified the type of biotope, elevation, aspect, and slope. We compared all of these parameters from resting sites with a paired randomly selected site to serve as a control. We performed a multiple logistic regression to identify the parameters associated with the resting sites and a point pattern analysis to describe their distribution. We characterized 43 resting sites and their corresponding control plots. At the microhabitat scale, resting sites were associated with higher vertical thermal cover, more concealment cover, more escape routes, more edible plant species, higher slope from the ground, and closer distance to water resources. At the landscape scale, resting sites were associated with beech forest, oak forest, secondary forest, and ravine biotopes and negatively associated with pine forest, houses, and roads. Resting sites had an aggregated spatial pattern from 0 to 900 m, but their distribution was completely random at larger scales. Our study revealed that Central American brocket deer selected places with specific characteristics to rest, at both microhabitat and landscape scales. We therefore suggest that existing habitat be increased by reforesting with native species—particularly Mexican beech forest and oak forest—to improve the deer’s conservation status in the study area.

Host tree selection by vascular epiphytes in tropical cloud forest of Hainan Island, China

Host tree selection by vascular epiphytes in tropical cloud forest of Hainan Island, China

Vascular epiphytes in the cloud forests of the Serra da Mantiqueira, Southeastern Region of Brazil

Abstract Vascular epiphytes represent a remarkable characteristic of the tropical cloud forests. The Serra da Mantiqueira (SM) represents one of the main highland areas of Brazil harboring vegetation remnants, and highlighting the cloud forests. We present a checklist of the vascular epiphytes found in the cloud forests of the SM, discussing the data about taxonomic representativity, distribution in the phytogeographic domains, habits, threatened status in Brazil and the states comprising the SM (Espírito Santo-ES, Minas Gerais-MG, Rio de Janeiro-RJ, São Paulo-SP). Field expeditions were performed between 2012 and 2019, as well as data gathering from scientific collections and published articles. We found 678 species, representing approximately 20% and 30% of the species found in Brazil and Atlantic forest, respectively. The richest families (Orchidaceae, 288 spp.; Bromeliaceae, 112 spp.; Polypodiaceae 65 spp.) corroborated the patterns found in different scales. Forty-one species are threatened nationally (and regionally, there are 149 in ES, 55 in MG, six in RJ, 31 in SP). These numbers of richness and threatened species highlight the relevance of directing efforts toward knowledge and conservation of both cloud forest remnants and SM as a whole, under pain of losing of a large part of the floristic diversity of Atlantic forest.

Spatiotemporal variation in the adult sex ratio, male aggregation, and movement of two tropical cloud forest dung beetles.

While theory suggests that at conception the sex ratio should be balanced (1:1), this can be variable across space and time in wild populations. Currently, studies of the environmental factors that regulate adult sex ratio (ASR) in species with different life history traits are scarce. Using capture-recapture over a year, we analyzed the influence of habitat type (forest and nonforest) and season (rainy and dry) on variation in ASR, male aggregation and the trajectory movement of 2 dung beetle species with different life history traits: Deltochilum mexicanum (a hornless roller species) and Dichotomius satanas (a tunneler species with horns on its head and thorax). We found opposite tendencies. The D. mexicanum population tends to be female-biased, but the population of D. satanas tends to be predominantly male, and observed values were not related to habitat type or season. However, the 95% confidence intervals estimated were highly variable between seasons depending on habitat. On examining the monthly variation in ASR for both habitats, we found that it depends on the species. In addition, male aggregation differed between species depending on habitat type and season, and species movement patterns were closely related to their habitat preferences. Based on our results, we argue that comparative population studies of species with different life history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.

Tracking Cloud Forests With Cloud Technology and Random Forests

Hotspots of endemic biodiversity, tropical cloud forests teem with ecosystem services such as drinking water, food, building materials, and carbon sequestration. Unfortunately, already threatened by climate change, the cloud forests in our study area are being further endangered during the Covid pandemic. These forests in northern Ecuador are being razed by city dwellers building country homes to escape the Covid virus, as well as by illegal miners desperate for money. Between August 2019 and July 2021, our study area of 52 square kilometers lost 1.17% of its tree cover. We base this estimate on simulations from the predictive model we built using Artificial Intelligence, satellite images, and cloud technology. When simulating tree cover, this model achieved an accuracy between 96 and 100 percent. To train the model, we developed a visual and interactive application to rapidly annotate satellite image pixels with land use and land cover classes. We codified our algorithms in an R package—loRax—that researchers, environmental organizations, and governmental agencies can readily deploy to monitor forest loss all over the world.

Gross ecosystem product accounting of national park: Taking Hainan Tropical Rainforest National Park as an example.

Hainan Tropical Rainforest National Park has the most representative and largest contiguous tropical rainforest in China, which has advantages in exploring the realization mechanism of ecological product value in national parks. Based on the basic framework of "The Technical Guideline on Gross Ecosystem Product (GEP)", we constructed a GEP accounting system in line with the characteristics of tropical rain forest national park, and calculated the GEP of Hainan Tropical Rainforest National Park in 2019. The results showed that the GEP of Hainan Tropical Rainforest National Park in 2019 was 204.513 billion yuan, and the GEP per unit area was 0.046 billion yuan·km-2. Among all the service types, the value of material services was 4.850 billion yuan, accounting for 2.4% of the total GEP in the national park. The ecosystem regulation service value was 168.891 billion yuan, accounting for 82.6%. The value of cultural services was 30.772 billion yuan, accounting for 15.0%. Among different ecosystem types, the unit area value of the tropical rain forest ecosystem represented by mountain rain forest, lowland rain forest, deciduous monsoon forest, and tropical cloud forest was much higher than that of plantation or other ecosystems, indicating the dominant role of tropical rain forest ecosystem in providing ecosystem services. In addition, based on the GEP accounting results of the national park, we put forward relevant suggestions for further exploring the realization path and realization mechanism of ecological product value.

The presence of Dry Forest Racer, Masticophis mentovarius (Duméril, Bibron & Duméril, 1854) (Squamata, Colubridae), in the Cloud Forest of Monteverde, Costa Rica

Masticophis mentovarius (Duméril, Bibron & Duméril, 1854) occurs at low and moderate elevations in Lowland Dry Forest and Premontane Moist Forest. This species is known in Costa Rica mainly from the dry lowlands of the northwest. Here we report the presence of M. mentovarius at the Tropical Cloud Forest of Monteverde, Costa Rica, at 1275 m a.s.l. The new records provide information on the true limits of the distribution of species and may represent expansion of the species’ range due to environmental changes caused by global climate change.

Drought responses of an exotic tree (Eriobotrya japonica) in a tropical cloud forest suggest the potential to become an invasive species

Drought responses of an exotic tree (Eriobotrya japonica) in a tropical cloud forest suggest the potential to become an invasive species

A new fog and low stratus retrieval for tropical South America reveals widespread fog in lowland forests

Fog-driven epiphyte-rich tropical cloud forests were long believed to be restricted to mountainous regions. Recent studies have shown the occurrence of such forest types in the lowlands of French Guiana, where early morning radiation fog was shown to modify the water and energy cycles at the canopy level of the tropical lowland rain forest (Gehrig-Downie et al., 2012; Obregon et al., 2011). Since this newly discovered Tropical Lowland Cloud Forest (TLCF) harbours a unique biodiversity comparable to mountain cloud forests, knowledge of its spatial distribution across tropical lowland forests is of large ecological interest, but so far fully unknown. A prerequisite to detect potential TLCF stands is knowledge on the spatial occurrence of fog/low stratus clouds (FLS) over longer time scales, indicating fog frequency. We address this need on a continental scale by presenting the first spatially-explicit, high-resolution product on nocturnal FLS occurrence over the entire tropical lowland rain forest area of South America. The product is based on a new FLS retrieval scheme that uses brightness temperature (BT) information of night-time satellite images acquired by the Aqua Moderate Imaging Spectroradiometer (Aqua MODIS). Since landforms substantially influence small-scale FLS development, we used a dynamic threshold technique depending on the spatially variable subpixel information on landform suitability for FLS generation. The product was successfully validated against in-situ visibility measurements combined with a plausibility analysis based on the published but scarce fog observations over the Amazon. The independence of the new algorithm from measured total precipitable water (TPW) is an improvement over existing procedures that are limited to the availability of these ancillary data. The FLS frequency map for the entire tropical lowland forest of South America derived from over 52,000 scenes (18 years from 2003 to 2020 inclusive) indicates that FLS is widespread, though spatially differentiated, throughout the tropical lowland forests of South America, providing suitable environmental conditions for the TLCF. This knowledge on the spatial distribution of potential TLCF is of major importance for conservation efforts. The new FLS scheme is applicable to all tropical lowland forests and can therefore support global conservation efforts of the valuable TLCF ecosystems.

Daily activity pattern of pumas (Puma concolor) and their potential prey in a tropical cloud forest of Colombia

Ecosystems in the northern Andes face unprecedented habitat loss. Pumas are the top predators in the region and exert key ecological functions, such as population control and resource facilitation. However, little is known about the temporal niche of the species or its effects on behaviour of prey in the tropics. We hypothesized that there is a link between the activity patterns of pumas and their prey in a cloud forest of the Central Andes of Colombia. We installed 61 camera traps to estimate the degree of overlap between the daily activity curves of pumas and seven potential prey species, using conditional kernel density functions. Pumas, armadillos, mountain pacas, and white–eared opossums were mainly nocturnal, with little crepuscular activity and high temporal overlap. Central American agouti, mountain coati, little red brocket deer, and Cauca guan displayed a predominantly diurnal activity and temporal partitioning with pumas. As opportunistic predators, pumas were able to maximize foraging efficiency by preying on the crepuscular and nocturnal species. Conservation of this highland predator will largely depend on the suitable management of its native prey.

Differing Trade-Off Patterns of Tree Vegetative Organs in a Tropical Cloud Forest.

Functional trait ecology demonstrates the significance of the leaf economics spectrum in understanding plants’ trade-off between acquisitive and conservative resource utilization. However, whether trait variations of different vegetative organs are coordinated and whether the plant economics spectrum is characterized by more than one vegetative organ remain controversial. To gain insights into these questions, within a tropical cloud forest in Hainan Island, a total of 13 functional traits of 84 tree species were analyzed here, including leaf, stem and root traits. By using standardized major axis (SMA) regression and principal components analysis, we examined the trait variations and correlations for deciphering plants’ trade-off pattern. We found decreases of leaf phosphorus content, leaf nitrogen content and specific leaf area and increases of leaf mass per unit area (LMA), wood density and leaf thickness along the first principal component, while there were decreases of specific root length and specific root area and increases of root tissue density along the second principal component. Root phosphorus and nitrogen contents were significantly positively associated with the phosphorus and nitrogen contents of both stem and leaf. Wood density was significantly positively associated with LMA and leaf thickness, but negatively associated with leaf thickness and specific leaf area. Our results indicate that, in the tropical cloud forest, there is a “fast–slow” economic spectrum characterized by leaf and stem. Changes of nutrient trait are coordinated, whereas the relationships of morphological traits varied independently between plant above- and below-ground parts, while root nutrient traits are decoupled from root morphological traits. Our findings can provide an insight into the species coexistence and community assembly in high-altitude tropical forests.

State changes: insights from the U.S. Long Term Ecological Research Network

AbstractUnderstanding the complex and unpredictable ways ecosystems are changing and predicting the state of ecosystems and the services they will provide in the future requires coordinated, long‐term research. This paper is a product of a U.S. National Science Foundation funded Long Term Ecological Research (LTER) network synthesis effort that addressed anticipated changes in future populations and communities. Each LTER site described what their site would look like in 50 or 100 yr based on long‐term patterns and responses to global change drivers in each ecosystem. Common themes emerged and predictions were grouped into state change, connectivity, resilience, time lags, and cascading effects. Here, we report on the “state change” theme, which includes examples from the Georgia Coastal (coastal marsh), Konza Prairie (mesic grassland), Luquillo (tropical forest), Sevilleta (arid grassland), and Virginia Coastal (coastal grassland) sites. Ecological thresholds (the point at which small changes in an environmental driver can produce an abrupt and persistent state change in an ecosystem quality, property, or phenomenon) were most commonly predicted. For example, in coastal ecosystems, sea‐level rise and climate change could convert salt marsh to mangroves and coastal barrier dunes to shrub thicket. Reduced fire frequency has converted grassland to shrubland in mesic prairie, whereas overgrazing combined with drought drive shrub encroachment in arid grasslands. Lastly, tropical cloud forests are susceptible to climate‐induced changes in cloud base altitude leading to shifts in species distributions. Overall, these examples reveal that state change is a likely outcome of global environmental change across a diverse range of ecosystems and highlight the need for long‐term studies to sort out the causes and consequences of state change. The diversity of sites within the LTER network facilitates the emergence of overarching concepts about state changes as an important driver of ecosystem structure, function, services, and futures.

Limited protection and ongoing loss of tropical cloud forest biodiversity and ecosystems worldwide.

Tropical cloud forests (TCFs) are one of the world's most species- and endemism-rich terrestrial ecosystems. TCFs are threatened by direct human pressures and climate change, yet the fate of these extraordinary ecosystems remains insufficiently quantified. With discussions of the post-2020 biodiversity framework underway, TCFs are a defining test case of the success and promise of recent policy targets and their associated mechanisms to avert the global biodiversity crisis. Here we present a global assessment of the recent status and trends of TCFs and their biodiversity and evaluate the efficacy of current protection measures. We find that cloud forests occupied 0.4% of the global land surface in 2001 and harboured ~3,700 species of birds, mammal, amphibians and tree ferns (~15% of the global diversity of those groups), with half of those species entirely restricted to cloud forests. Worldwide, ~2.4% of cloud forests (in some regions, more than 8%) were lost between 2001 and 2018, especially in readily accessible places. While protected areas have slowed this decline, a large proportion of loss in TCF cover is still occurring despite formal protection. Increased conservation efforts are needed to avert the impending regional or global demise of TCFs and their unique biodiversity.

Vegetation structure and biodiversity recovery in 19-year-old active restoration plantations in a Neotropical cloud forest

Aim of the study: To evaluate how middle-aged active restoration plantations of native tree species contribute to the recovery of the tropical cloud forest in terms of vegetation structure, tree richness, species composition, and to shade-tolerance and seed dispersal mode functional groups.Area of the study: We studied two 19-year-old active restoration sites and their reference mature forests in the tropical montane cloud forest belt, Veracruz, Mexico.Materials and methods: The basal area, density and height as well as the tree species composition and number of species and individuals classified by shade tolerance (pioneer and non-pioneer trees), and seed dispersal mode (anemochorous, barochorous-synzoochorous and endozoochorous) were compared between active restoration plantations and reference forests.Main results: Planted trees and the woody vegetation growing under them represented a high proportion of reference forests’ basal area. Tree richness and Shannon’s equitability index were similar in both reference forests and one active restoration plantation and slightly different in the other. Tree species composition differed among sites; however, each 19-year-old plantation already had several non-pioneer species and a similar species proportion of the seed dispersal syndromes present in their reference forests.Research highlights: Active restoration accelerated the recovery of cloud forest in degraded pasture and bracken fern lands. Planted trees promoted the rapid development of vegetation structure and natural tree regeneration. Although species composition is still different, these middle-aged restoration plantations already have forest species and a proportion of functional groups of species similar to those of their own reference montane cloud forests.Keywords: active restoration; forest recovery; passive restoration; seed dispersal mode; succession; tree species; tropical montane cloud forest.

Litterfall, vegetation structure and tree composition as indicators of functional recovery in passive and active tropical cloud forest restoration

Litterfall is an indicator of ecosystem function and its temporal dynamics can be used to evaluate self-organizing ecosystems on a recovery trajectory following restoration. Few studies have evaluated the recovery trajectories of forest litterfall by simultaneously monitoring forest restoration strategies and reference ecosystems. The general objective of our study was to determine the functional recovery of an abandoned pasture under passive and active restoration, and in secondary (40-year-old) and mature (120-year-old) forest, by analyzing litterfall and its components (leaves, flowers, fruits, woody parts) over a period of five consecutive years. We determined the vegetation structure and tree species composition of these four conditions and compared 1) production of litterfall, leaves, flowers and fruits, 2) leaf litter nutrient inputs (C and N) and, 3) recovery by tree species in leaf litterfall. In five years, litterfall increased from 2.6 to 7.8 Mg ha−1 and from 3.5 to 9.1 Mg ha−1 in the passive and active restoration treatments, respectively, while it increased from 6.0 to 8.6 Mg ha−1 in the secondary forest. In the mature forest, litterfall varied around 10.0 Mg ha−1. The reproductive component increased significantly in restoration (0.3 to 1.5 Mg ha−1) but remained around 0.6 Mg ha−1 in secondary and 1.3 Mg ha−1 in mature forest. Secondary and mature forests both presented correlations to monthly precipitation and maximum and minimum temperatures, indicating strong seasonality. However, litterfall production in the passive and active treatments was continuous throughout the year. Basal area and tree density were higher under active compared to passive restoration. Although the dominant tree species were similar under passive and active restoration, active restoration presented a higher forest species recovery, while the dominance of exotic grass patches persisted under passive restoration. The results suggest that litterfall production can be a useful and accurate indicator with which to evaluate the recovery of ecosystem function, while flower and fruit component can indicate reproductive recovery. Although litterfall production increased rapidly after five years, it did not present a seasonal dynamic. This is probably due to the fact that the species composition still differs from that of the reference systems. Evaluations of cloud forest restoration success should therefore include temporal assessments of vegetation structure and biodiversity recovery in relation to the reference forests in order to establish additional restoration techniques, particularly in the case of passive restoration strategies.

Smardaea isoldae sp. nov. from a tropical cloud forest in Mexico

Smardaea isoldae is described from Sierra Madre Oriental, Hidalgo State, Mexico. The new species is distinguished by its olivaceous coloration, habit on dead wood, and tropical cloud forest habitat. The holotype is deposited in ENCB Herbarium. A key to Smardaea species is presented.

Accelerating tropical cloud forest recovery: Performance of nine late-successional tree species

Tree planting is a common strategy for forest restoration. The use of mid- and late-successional species is less common, but could accelerate succession, enhance diversity and secure their presence. In this study, we determined the survival and growth of 559 saplings from nine native mid- and late-successional species after three years of growth under a range of habitat conditions to evaluate their potential utility in restoration plantings. Since mid- and late-successional tree species have shade-tolerant attributes and the light environment is a determinant factor for their growth and survival, we expected sapling performance to vary among species depending on the percentage of canopy cover and on factors associated with this variable. For this, we identified habitat conditions that influenced sapling performance in a degraded tropical cloud forest: the conditions ranged from closed-canopy secondary forest to open pastures dominated by exotic grasses. Overall, the studied species presented a high performance: sapling survival (40 to 90%) and relative growth rates in height (0.14 to 0.50 cm cm−1 year−1) and in diameter (0.04 to 0.50 mm mm−1 year−1) were within or above the ranges previously reported for cloud forest species. The final sizes and growth rates in height and diameter were mostly explained by the canopy and grass cover (71.5% of the variation). Integrated Response Index (IRI) values showed wide variation among species (from 6.44 to 41.41 with inclusion of height, and from 2.13 to 44.77 with inclusion of diameter). In general, there was a negative correlation between canopy cover and final sapling size and growth rates in height and diameter, but there were important variations among species. Based on their IRI values, species such as Ulmus mexicana and Oreomunnea mexicana are suggested for restoration plantings. Given their low performance, however, Fraxinu uhdei and Juglans pyriformis are recommended for use only in advanced forest successional stages or in conjunction with other restoration techniques to increase their survival. Our results show that these threatened mid- and late-successional native species can be successfully matched to microsite conditions and established in degraded areas as a strategy by which to secure their presence and accelerate forest recovery.

Spatial relationships between spiders and their host vascular epiphytes within shade trees in a Mexican coffee plantation

AbstractWithin tree canopies, vascular epiphytes create habitats for other taxa, and their heterogeneous spatial distribution could affect the distribution of organisms associated with them, such as spiders. This study was performed in shade trees of a rustic coffee plantation located within a Tropical Cloud Forest region of Mexico. We used a spatially explicit approach to examine (1) if the richness and abundance of epiphyte‐dwelling spiders have a positive association with epiphyte abundance within trees and (2) if spiders (richness and abundance) show the same patterns of spatial distribution as the epiphytic habitat. We found that spiders were distributed on gradients of the same type as their host epiphytes. These gradients were a decrease from the center toward the edges of the tree and a decrease from the base of the trunk toward the canopy. Spiders also had aggregation patches with similar dimensions to those exhibited by their host epiphytes. Those spiders' patches were fully explained when their epiphytic habitat was also aggregated within trees. Spatial models suggested that epiphytes and spiders were also spatially structured at scales larger than a tree and smaller than an epiphyte mat. Our findings demonstrate that the spatial distribution of epiphyte‐dwelling spider communities, may partly be explained by the distribution patterns of their host plants. However, other environmental and biotic factors, not associated with epiphyte communities, are likely to be responsible for the remaining spatial patterns of spider distribution.Abstract in Spanish is available with online material.