Drivers of plant diversity, community composition, functional traits, and soil processes along an alpine gradient in the central Chilean Andes.

High alpine regions are threatened but understudied ecosystems that harbor diverse endemic species, making them an important biome for testing the role of environmental factors in driving functional trait-mediated community assembly processes. We tested the hypothesis that plant community assembly along a climatic and elevation gradient is influenced by shifts in habitat suitability, which drive plant functional, phylogenetic, and spectral diversity. In a high mountain system (2400-3500 m) Región Metropolitana in the central Chilean Andes (33°S, 70°W). We surveyed vegetation and spectroscopic reflectance (400-2400 nm) to quantify taxonomic, phylogenetic, functional, and spectral diversity at five sites from 2400 to 3500 m elevation. We characterized soil attributes and processes by measuring water content, carbon and nitrogen, and net nitrogen mineralization rates. At high elevation, colder temperatures reduced available soil nitrogen, while at warmer, lower elevations, soil moisture was lower. Metrics of taxonomic, functional, and spectral alpha diversity peaked at mid-elevations, while phylogenetic species richness was highest at low elevation. Leaf nitrogen increased with elevation at the community level and within individual species, consistent with global patterns of increasing leaf nitrogen with colder temperatures. The increase in leaf nitrogen, coupled with shifts in taxonomic and functional diversity associated with turnover in lineages, indicate that the ability to acquire and retain nitrogen in colder temperatures may be important in plant community assembly in this range. Such environmental filters have important implications for forecasting shifts in alpine plant communities under a warming climate.

Topsoil and subsoil bacterial community assemblies across different drainage conditions in a mountain environment.

BACKGROUND: High mountainous environments are of particular interest as they play an essential role for life and human societies, while being environments which are highly vulnerable to climate change and land use intensification. Despite this, our knowledge of high mountain soils in South America and their microbial community structure is strikingly scarce, which is of more concern considering the large population that depends on the ecosystem services provided by these areas. Conversely, the Central Andes, located in the Mediterranean region of Chile, has long been studied for its singular flora, whose diversity and endemism has been attributed to the particular geological history and pronounced environmental gradients in short distances. Here, we explore soil properties and microbial community structure depending on drainage class in a well-preserved Andean valley on the lower alpine vegetation belt (~2500 m a.s.l.) at 33.5˚S. This presents an opportunity to determine changes in the overall bacterial community structure across different types of soils and their distinct layers in a soil depth profile of a highly heterogeneous environment. METHODS: Five sites closely located (<1.5 km) and distributed in a well preserved Andean valley on the lower alpine vegetation belt (~2500 m a.s.l.) at 33.5˚S were selected based on a pedological approach taking into account soil types, drainage classes and horizons. We analyzed 113 soil samples using high-throughput sequencing of the 16S rRNA gene to describe bacterial abundance, taxonomic composition, and co-occurrence networks. RESULTS: Almost 18,427 Amplicon Sequence Variant (ASVs) affiliated to 55 phyla were detected. The bacterial community structure within the same horizons were very similar validating the pedological sampling approach. Bray-Curtis dissimilarity analysis revealed that the structure of bacterial communities in superficial horizons (topsoil) differed from those found in deep horizons (subsoil) in a site-specific manner. However, an overall closer relationship was observed between topsoil as opposed to between subsoil microbial communities. Alpha diversity of soil bacterial communities was higher in topsoil, which also showed more bacterial members interacting and with higher average connectivity compared to subsoils. Finally, abundances of specific taxa could be considered as biological markers in the transition from topsoil to subsoil horizons, like Fibrobacterota, Proteobacteria, Bacteroidota for shallower soils and Chloroflexi, Latescibacterota and Nitrospirota for deeper soils. CONCLUSIONS: The results indicate the importance of the soil drainage conditions for the bacterial community composition, suggesting that information of both structure and their possible ecological relationships, might be useful in clarifying the location of the edge of the topsoil-subsoil transition in mountainous environments.

Elevation provenance affects photosynthesis and its acclimation to temperature in the high-Andes alpine herb Phacelia secunda.

We analysed whether Phacelia secunda populations from different elevations exhibit intrinsic traits associated with diffusive and biochemical components of photosynthesis, and if they differ in acclimation of photosynthesis to warmer temperatures. We hypothesized that P. secunda will have similar photosynthetic performance regardless of altitudinal provenance and that plants from high elevations will have a lower photosynthetic acclimation capacity to higher temperature than plants from low elevations. Plants from 1600, 2800 and 3600 m a.s.l. in the central Chilean Andes were collected and grown under two temperature regimes (20/16 °C and 30/26 °C day/night). The following photosynthetic traits were measured in each plant for the two temperature regimes: AN , gs , gm , Jmax , Vcmax , Rubisco carboxylation kcat c . Under a common growth environment, plants from the highest elevation had slightly lower CO2 assimilation rates compared to lower elevation plants. While diffusive components of photosynthesis increased with elevation provenance, the biochemical component decreased, suggesting compensation that explains the similar rates of photosynthesis among elevation provenances. Plants from high elevations had lower photosynthetic acclimation to warmer temperatures compared to plants from lower elevations, and these responses were related to elevational changes in diffusional and biochemical components of photosynthesis. Plants of P. secunda from different elevations maintain photosynthetic traits when grown in a common environment, suggesting low plasticity to respond to future climate changes. The fact that high elevation plants had lower photosynthetic acclimation to warmer temperature suggests higher susceptibility to increases in temperature associated with global warming.

Organochlorine pesticides and polychlorinated biphenyls in high mountain lakes, Mexico.

Pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the El Sol and the La Luna alpine lakes. The lakes are located in central Mexico, in the crater of the Nevado de Toluca volcano. The El Sol and the La Luna lakes are extremely relevant in Mexico and in the world because they are recognized as pristine regions and environmental reservoirs. Samples of atmospheric aerosol, sediment, plankton, and Tubifex tubifex (sludge worm) were collected at three different sample locations for three years (2017, 2018, and 2019) at three different times of year, meaning that the weather conditions at the time of sampling were different. Pollutants were analysed by gas chromatography-mass spectrometry with negative chemical ionisation (GC-MS/NCI). Endosulfan was the most frequent and abundant pollutant, showing the highest peaks of all. Atmospheric aerosol revealed Σ2 = 45 pg/m3, including α and ß, while sediment lakes displayed α, ß and endosulfan sulfate as Σ3 = 1963 pg/g, whereas plankton and Tubifex tubifex showed Σ2 = 576 pg/g and 540 pg/g for α and ß respectively. Results of endosulfan ratios (α/ß) and (α-ß/endosulfan sulfate) suggest that both fresh and old discharges continue to arrive at the lakes. This study shows for the first time the pollution levels of OCP and PCB in high mountain lakes in Mexico. These results that must be considered by policy makers to mitigate their use in the various productive activities of the region.

Relieving your stress: PGPB associated with Andean xerophytic plants are most abundant and active on the most extreme slopes.

Introduction: Plants interact with plant growth-promoting bacteria (PGPB), especially under stress condition in natural and agricultural systems. Although a potentially beneficial microbiome has been found associated to plants from alpine systems, this plant- PGPB interaction has been scarcely studied. Nevados de Chillán Complex hold one of the southernmost xerophytic formations in Chile. Plant species living there have to cope with drought and extreme temperatures during the growing season period, microclimatic conditions that become harsher on equatorial than polar slopes, and where the interaction with PGPB could be key for plant survival. Our goal was to study the abundance and activity of different PGPB associated to two abundant plant species of Andean xerophytic formations on contrasting slopes. Methods: Twenty individuals of Berberis empetrifolia and Azorella prolifera shrubs were selected growing on a north and south slope nearby Las Fumarolas, at 2,050 m elevation. On each slope, microclimate based on temperature and moisture conditions were monitored throughout the growing period (oct. - apr.). Chemical properties of the soil under plant species canopies were also characterized. Bacterial abundance was measured as Log CFU g-1 from soil samples collected from each individual and slope. Then, the most abundant bacterial colonies were selected, and different hormonal (indoleacetic acid) and enzymatic (nitrogenase, phosphatase, ACC-deaminase) mechanisms that promote plant growth were assessed and measured. Results and Discussion: Extreme temperatures were observed in the north facing slope, recording the hottest days (41 vs. 36°C) and coldest nights (-9.9 vs. 6.6°C). Moreover, air and soil moisture were lower on north than on south slope, especially late in the growing season. We found that bacterial abundance was higher in soils on north than on south slope but only under B. empetrifolia canopy. Moreover, the activity of plant growth-promoting mechanisms varied between slopes, being on average higher on north than on south slope, but with plant species-dependent trends. Our work showed how the environmental heterogeneity at microscale in alpine systems (slope and plant species identity) underlies variations in the abundance and plant growth promoting activity of the microorganisms present under the plant canopy of the Andean xerophytic formations and highlight the importance of PGPB from harsh systems as biotechnological tools for restoration.

Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species.

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82-98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata´s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

Shifts in soil and plant functional diversity along an altitudinal gradient in the French Alps.

OBJECTIVES: Altitude integrates changes in environmental conditions that determine shifts in vegetation, including temperature, precipitation, solar radiation and edaphogenetic processes. In turn, vegetation alters soil biophysical properties through litter input, root growth, microbial and macrofaunal interactions. The belowground traits of plant communities modify soil processes in different ways, but it is not known how root traits influence soil biota at the community level. We collected data to investigate how elevation affects belowground community traits and soil microbial and faunal communities. This dataset comprises data from a temperate climate in France and a twin study was performed in a tropical zone in Mexico. DATA DESCRIPTION: The paper describes soil physical and chemical properties, climatic variables, plant community composition and species abundance, plant community traits, soil microbial functional diversity and macrofaunal abundance and diversity. Data are provided for six elevations (1400-2400 m) ranging from montane forest to alpine prairie. We focused on soil biophysical properties beneath three dominant plant species that structure local vegetation. These data are useful for understanding how shifts in vegetation communities affect belowground processes, such as water infiltration, soil aggregation and carbon storage. Data will also help researchers understand how plant communities adjust to a changing climate/environment.

Alpine vegetation in the context of climate change: A global review of past research and future directions.

Climate change is causing extensive alterations to ecosystems globally, with some more vulnerable than others. Alpine ecosystems, characterised by low-temperatures and cryophilic vegetation, provide ecosystems services for billions of people but are considered among the most susceptible to climate change. Therefore, it is timely to review research on climate change on alpine vegetation including assessing trends, topics, themes and gaps. Using a multicomponent bibliometric approach, we extracted bibliometric metadata from 3143 publications identified by searching titles, keywords and abstracts for research on 'climate change' and 'alpine vegetation' from Scopus and Web of Science. While primarily focusing on 'alpine vegetation', some literature that also assessed vegetation below the treeline was captured. There has been an exponential increase in research over 50 years, greater engagement and diversification in who does research, and where it is published and conducted, with increasing focus beyond Europe, particularly in China. Content analysis of titles, keywords and abstracts revealed that most of the research has focused on alpine grasslands but there have been relatively few publications that examine specialist vegetation communities such as snowbeds, subnival vegetation and fellfields. Important themes emerged from analysis of keywords, including treelines and vegetation dynamics, biodiversity, the Tibetan Plateau as well as grasslands and meadows. Traditional ecological monitoring techniques were important early on, but remote sensing has become the primary method for assessment. A key book on alpine plants, the IPCC reports and a few papers in leading journals underpin much of the research. Overall, research on this topic is increasing, with new methods and directions but thematic and geographical gaps remain particularly for research on extreme climatic events, and research in South America, in part due to limited capacity for research on these rare but valuable ecosystems.

Going off trails: How dispersed visitor use affects alpine vegetation.

Mountain protected areas provide a range of ecosystem services including conserving biodiversity, while often providing recreation and tourism opportunities. Unfortunately, tourists and pack animals used to transport equipment can damage sensitive alpine vegetation particularly when they leave trails. This study assessed the impacts of disturbance from off trail use on alpine vegetation in a popular park in the Andes. The effect of different levels of disturbance as well as abiotic factors on alpine steppe vegetation was assessed using generalized linear models and ordinations in 91 plots (20 m2) in the popular Horcones Valley that is used to access remote areas in Aconcagua Provincial Park in Argentina. Disturbance off trails resulted in declines in the cover of native plants, including the endemic shrub Adesmia aegiceras but increases in the cover of herbs including the non-native Convolvulus arvensis. Increased disturbance was associated with shifts from stress tolerant species to ruderal plants characterized by more acquisitive traits, including shorter plants with greater Specific Leaf Area. The research demonstrates the severity of impacts from off trail trampling including how trampling favours some species with specific traits over others and why it is important to limit off track use in areas of high conservation value.

Intake, digestibility, ingestive behavior, production, and composition of goat milk supplemented with detoxified castor bean meal added urea as a replacement of soybean meal.

This study evaluated the castor bean meal detoxified with calcium hydroxide [Ca(OH)2] added urea replacing soybean meal in the diet of lactating goats from milk production and composition, intake, digestibility, and ingestive behavior. Eight Alpine multiparous goats weighting 44.3 ± 5.3 kg and at approximately 60 days of lactation were confined and randomly distributed in 4 × 4 double Latin squares, with four inclusion levels of detoxified castor meal: control (0), 25, 50, and 75 g/kg dry matter (DM) total. Detoxified castor bean meal replacing soybean meal (P > 0.05) in goats diet did not affect intake and digestibility of DM, crude protein, ether extract, neutral detergent fiber (NDF), total carbohydrates, non-fibrous carbohydrates and total digestible nutrients, times spent for eating, and efficiency ratios of rumination and eating. However, the times spent for rumination and idling showed a quadratic trend decrease (P < 0.01) from the level of 50.0-g/kg DM. The milk production, and the milk production correction showed a quadratic trend increase and feeding efficiency a quadratic decrease (P = 0.03) due inclusion of detoxified castor bean meal replacing soybean meal up to the level of 25.0 g/kg. The fat, protein, lactose, total solids, nonfat solids, and milk urea nitrogen content (g/day) presented a quadratic increase (P < 0.05) by detoxified castor meal inclusion. Detoxified castor bean meal added urea in the Alpine goats diet could be included up to the 25.0 g/kg level replacing soybean meal in the diet because improve milk production and composition and feeding efficiency of goats without negatively effect on intake, digestibility and ingestive behavior.

Impacts of climate, soil and biotic interactions on the interplay of the different facets of alpine plant diversity.

Disentangling the processes that drive plant community assembly is critical for understanding the patterns of plant diversity. We studied how different abiotic and biotic factors shape the interplay between the facets of alpine plant diversity, functional (FD), phylogenetic (PD) and taxonomic diversity (TD), in three different mountain ranges with contrasting evolutionary histories and climate conditions (Pyrenees and Mediterranean-type mountains in central Spain and Chilean Andes). We hypothesized that the causal links vary in strength and sign across regions. We used species inventories, functional trait data, and a phylogeny from 84 plant communities spread throughout three high-mountain alpine grasslands. Structural equation models were used to test our causal hypotheses on the relationships observed between the three diversity facets, and the abiotic (elevation, potential solar radiation and soil total nitrogen) and biotic factors (C-score). Despite our causal model presented a high variability in each mountain range, TD always decreased with increasing elevation (sum of direct and indirect effects). We also found some patterns suggesting that assembly processes could be climatically/biogeographically structured such as the negative relationship between FD and elevation found in Mediterranean mountains and the negative relationship between FD and TD found in both Spanish mountain ranges (independently of their different climates). A remarkable finding of this study is that ecological factors such as soil total nitrogen and elevation indirectly alter the relationships between the diversity facets. Our results suggest that diversity facets are simultaneously affected by different ecological and biogeographical/evolutionary processes, resulting in some general trends but also in parallel idiosyncratic patterns. Our findings highlight that although FD stand out by its explanatory power of community processes, TD and PD provide a complementary and necessary view that should not be disregarded in the attempt to globally explain community assembly processes.

Ethnobotany of the Sierra Nevada del Cocuy-Güicán: climate change and conservation strategies in the Colombian Andes.

BACKGROUND: The Sierra Nevada del Cocuy-Güicán in the Colombian Andes is protected as a National Natural Park since 1977 because of its fragile páramo ecosystems, extraordinary biodiversity, high plant endemism, and function as water reservoir. The vegetation on this mountain is threatened by expanding agriculture, deforestation, tourism, and climate change. We present an ethnobotanical inventory among local farmer communities and discuss the effects of vegetation change on the availability of useful plants. METHODS: We used 76 semi-structured, 4 in-depth interviews, and 247 botanical collections to record the ethnoflora of the farmers and surveyed from the high Andean forest to the super-páramo, including native and introduced species. We organized 3 participative workshops with local children, high school students, and campesinos' women to share the data we acquired in the field and empower local plant conservation awareness. RESULTS: We encountered 174 useful plants, most of them native to the area (68%) and almost one third introduced (32%). The Compositae was the most species-rich family, followed by Lamiaceae, Poaceae, and Rosaceae. The majority of plant species were used as medicine, followed by food, firewood, and domestic tools. Local farmers reported declining numbers of páramo species, which were now only found at higher altitudes than before. Although our informants were worried about the preservation of their natural resources and noticed the effects of climate change, for several commercial species, unsustainable land use and overharvesting seemed to be the direct cause of declining medicinal plant resources rather than climate change. CONCLUSIONS: We recommend conservation plans that include vegetation monitoring, people's perceptions on climate change, and participative actions with the communities of the Sierra Nevada del Cocuy-Güicán.

Using crowd-sourced photos to assess seasonal patterns of visitor use in mountain-protected areas.

Managing protected areas effectively requires information about patterns of visitor use, but these data are often limited. We explore how geotagged photos on Flickr, a popular photo-sharing social-media site, can generate hotspot maps and distribution models of temporal and spatial patterns of use in two mountain-protected areas of high conservation value. In Aconcagua Provincial Park (Argentina), two routes to the summit of Aconcagua were used in summer, but most visitors stayed close to the main road, using formal and informal walking trails and the Visitor Centre, while in winter, there was very limited visitation. In Kosciuszko National Park (Australia), alpine walking trails were popular in summer, but in winter, most visitors stayed in the lower altitude ski resorts and ski trails. Results demonstrate the usefulness of social-media data alone as well as a complement for visitor monitoring, providing spatial and temporal information for site-specific and park-level management of visitors and potential impacts in conservation areas.

Long-term in situ persistence of biodiversity in tropical sky islands revealed by landscape genomics.

Tropical mountains are areas of high species richness and endemism. Two historical phenomena may have contributed to this: (i) fragmentation and isolation of habitats may have promoted the genetic differentiation of populations and increased the possibility of allopatric divergence and speciation and (ii) the mountain areas may have allowed long-term population persistence during global climate fluctuations. These two phenomena have been studied using either species occurrence data or estimating species divergence times. However, only few studies have used intraspecific genetic data to analyse the mechanisms by which endemism may emerge at the microevolutionary scale. Here, we use landscape analysis of genomic SNP data sampled from two high-elevation plant species from an archipelago of tropical sky islands (the Trans-Mexican Volcanic Belt) to test for population genetic differentiation, synchronous demographic changes and habitat persistence. We show that genetic differentiation can be explained by the degree of glacial habitat connectivity among mountains and that mountains have facilitated the persistence of populations throughout glacial/interglacial cycles. Our results support the ongoing role of tropical mountains as cradles for biodiversity by uncovering cryptic differentiation and limits to gene flow.

The ontogenetic allometry of body morphology and chemical composition in dairy goat wethers.

We studied the ontogenetic growth of goat wethers (castrated male goats) of the Saanen and Swiss Alpine breeds based on a large range of intraspecific body mass (BM). The body parts and the chemical constituents of the empty body were described by the allometric function by using BM and the empty body mass (EBM) as the predictors for morphological traits and chemical composition, respectively. We fitted the allometric scaling function by applying the SAS NLMIXED procedure, but to evaluate assumptions regarding variances in morphological and compositional traits, we combined the scaling function with homoscedastic (MOD1), and the heteroscedastic exponential (MOD2) and power-of-the-mean (MOD3) variance functions. We also predicted the ontogenetic growth by using the traditional log-log transformation and back-transformed results into the arithmetic scale (MOD4). We obtained predictions from MOD4 in the arithmetic scale by a two-step process, and evaluated MOD1, MOD2 and MOD3 by a model selection framework, and compared MOD4 with MOD1, MOD2 and MOD3 based on goodness-of-fit measures. Based on information criteria for model selection, heterogeneous variance functions were more likely to describe 10 over 36 traits with a low level of model selection uncertainty. One trait was predicted by averaging the MOD1 and MOD2 variance functions; and nine traits were better described by averaging the MOD2 and MOD3 variance functions. The predictions for other 16 traits were averaged from MOD1, MOD2 and MOD3. However, MOD4 better described 11 traits according to the goodness-of-fit measures. Depending on the variable being analyzed, the body parts and the chemical amounts exhibited the three types of allometric behavior with respect to BM and EBM, that is, positive, negative and isometric ontogenetic growth. Reference BMs, that is, 20, 27, 35 and 45 kg, were used to compute the net protein and energy requirements based on the first derivative of the scaling function, and the results were presented in reference to the EBM and EBM0.75. Both the net protein and energy requirements scaled to EBM0.75 increased from 20 to 45 kg of BM.

Productive and economic performance of goats of different genetic groups / Desempenho produtivo e econômico de cabritos de diferentes grupos genéticos

This study aimed to evaluate the bio-economic performance in confinement crossbred goats from different genetic groups. Were used 30 goats, crossbred (F1) intact male, 10 goats Boer x SPRD (undefined breed), 10 x Savannah SPRD and 10 Oberhasli x SPRD, with an average weight of 15 kg and an average age of 100 days. The initial weight was evaluated, final body weight, average daily gain, total weight gain, dry matter intake, water intake, feed conversion and days on feed. As an economic indicator was calculated gross profit margin (MB), the average dry matter intake, the confinement period, the cost of each diet and the cost of vaccines and medicines. We used the 5% Tukey test for comparisons between treatment means. For the variables weight gain, dry matter intake, water intake and body condition score averages observed did not differ between the genetic groups. There was significant effect (P> 0.05) of genetic groups on days on feed. The biological performance of the goats finished in feedlot was not influenced by genetic group. In bioeconomic analysis was no significant difference (P> 0.05) between the evaluated racial groups. Gross profit margin was negative for the mestizos Pardo Alpine x SPRD. The cross between the Boer breed and without defined breed results in premature animals, reaching slaughter weights with reduced confinement period. In the feedlot finishing system crossbred Boer goats x SPRD showed better economic performance, providing greater profitability to the creator.

Objetivou-se avaliar o desempenho bioecônomico em confinamento de cabritos mestiços, de diferentes grupamentos genéticos. Foram utilizados 30 cabritos, mestiços (F1), machos não castrados, sendo 10 cabritos Boer x SPRD (Sem Raça Definida), 10 Savana x SPRD e 10 Pardo Alpino x SPRD, com peso médio de 15 kg e idade média de 100 dias. O delineamento utilizado foi o inteiramente casualizado com três tratamentos (genótipos) e 10 repetições. Avaliou-se o peso inicial, peso vivo final, ganho de peso médio diário, ganho de peso total, consumo de matéria seca, consumo de água, e conversão alimentar e dias de confinamento. Como indicador econômico foi calculado a margem bruta de lucro (MB), o consumo médio de matéria seca, o período de confinamento, o custo de cada dieta e as despesas com vacinas e medicamentos. Utilizou-se o teste de Tukey a 5% para as comparações entre as médias dos tratamentos. Para as variáveis, ganho de peso, consumo de matéria seca, consumo de água e escore corporal, as médias observadas não diferiram entre os grupos genéticos. Houve efeito significativo (P>0,05) dos grupos genéticos sobre os dias de confinamento. O desempenho biológico dos cabritos terminados em confinamento não foi influenciado pelo grupo genético. Na análise bioeconômica houve diferença significativa (P>0,05) entre os grupos raciais avaliados. A margem bruta de lucro foi negativa para os mestiços Pardo Alpino x SPRD. O cruzamento entre a raça Boer e animais sem padrão racial definido resulta em animais mais precoces, alcançando pesos ao abate com período de confinamento reduzido. No sistema de terminação em confinamento, os cabritos mestiços de Boer x SPRD apresentaram melhor desempenho econômico, proporcionando uma maior lucratividade para o criador.

Productive and economic performance of goats of different genetic groups / Desempenho produtivo e econômico de cabritos de diferentes grupos genéticos

This study aimed to evaluate the bio-economic performance in confinement crossbred goats from different genetic groups. Were used 30 goats, crossbred (F1) intact male, 10 goats Boer x SPRD (undefined breed), 10 x Savannah SPRD and 10 Oberhasli x SPRD, with an average weight of 15 kg and an average age of 100 days. The initial weight was evaluated, final body weight, average daily gain, total weight gain, dry matter intake, water intake, feed conversion and days on feed. As an economic indicator was calculated gross profit margin (MB), the average dry matter intake, the confinement period, the cost of each diet and the cost of vaccines and medicines. We used the 5% Tukey test for comparisons between treatment means. For the variables weight gain, dry matter intake, water intake and body condition score averages observed did not differ between the genetic groups. There was significant effect (P> 0.05) of genetic groups on days on feed. The biological performance of the goats finished in feedlot was not influenced by genetic group. In bioeconomic analysis was no significant difference (P> 0.05) between the evaluated racial groups. Gross profit margin was negative for the mestizos Pardo Alpine x SPRD. The cross between the Boer breed and without defined breed results in premature animals, reaching slaughter weights with reduced confinement period. In the feedlot finishing system crossbred Boer goats x SPRD showed better economic performance, providing greater profitability to the creator.(AU)

Objetivou-se avaliar o desempenho bioecônomico em confinamento de cabritos mestiços, de diferentes grupamentos genéticos. Foram utilizados 30 cabritos, mestiços (F1), machos não castrados, sendo 10 cabritos Boer x SPRD (Sem Raça Definida), 10 Savana x SPRD e 10 Pardo Alpino x SPRD, com peso médio de 15 kg e idade média de 100 dias. O delineamento utilizado foi o inteiramente casualizado com três tratamentos (genótipos) e 10 repetições. Avaliou-se o peso inicial, peso vivo final, ganho de peso médio diário, ganho de peso total, consumo de matéria seca, consumo de água, e conversão alimentar e dias de confinamento. Como indicador econômico foi calculado a margem bruta de lucro (MB), o consumo médio de matéria seca, o período de confinamento, o custo de cada dieta e as despesas com vacinas e medicamentos. Utilizou-se o teste de Tukey a 5% para as comparações entre as médias dos tratamentos. Para as variáveis, ganho de peso, consumo de matéria seca, consumo de água e escore corporal, as médias observadas não diferiram entre os grupos genéticos. Houve efeito significativo (P>0,05) dos grupos genéticos sobre os dias de confinamento. O desempenho biológico dos cabritos terminados em confinamento não foi influenciado pelo grupo genético. Na análise bioeconômica houve diferença significativa (P>0,05) entre os grupos raciais avaliados. A margem bruta de lucro foi negativa para os mestiços Pardo Alpino x SPRD. O cruzamento entre a raça Boer e animais sem padrão racial definido resulta em animais mais precoces, alcançando pesos ao abate com período de confinamento reduzido. No sistema de terminação em confinamento, os cabritos mestiços de Boer x SPRD apresentaram melhor desempenho econômico, proporcionando uma maior lucratividade para o criador.(AU)

Functional role of long-lived flowers in preventing pollen limitation in a high elevation outcrossing species.

Low pollinator visitation in harsh environments may lead to pollen limitation which can threaten population persistence. Consequently, avoidance of pollen limitation is expected in outcrossing species subjected to habitually low pollinator service. The elevational decline in visitation rates on many high mountains provides an outstanding opportunity for addressing this question. According to a recent meta-analysis, levels of pollen limitation in alpine and lowland species do not differ. If parallel trends are manifested among populations of alpine species with wide elevational ranges, how do their uppermost populations contend with lower visitation? We investigated visitation rates and pollen limitation in high Andean Rhodolirium montanum. We test the hypothesis that lower visitation rates at high elevations are compensated for by the possession of long-lived flowers. Visitation rates decreased markedly over elevation as temperature decreased. Pollen limitation was absent at the low elevation site but did occur at the high elevation site. While initiation of stigmatic pollen deposition at high elevations was not delayed, rates of pollen arrival were lower, and cessation of pollination, as reflected by realized flower longevity, occurred later in the flower lifespan. Comparison of the elevational visitation decline and levels of pollen limitation indicates that flower longevity partially compensates for the lower visitation rates at high elevation. The functional role of flower longevity, however, was strongly masked by qualitative pollen limitation arising from higher abortion levels attributable to transference of genetically low-quality pollen in large clones. Stronger clonal growth at high elevations could counterbalance the negative fitness consequences of residual pollen limitation due to low visitation rates and/or difficult establishment under colder conditions. Visitation rates on the lower part of the elevational range greatly exceeded community rates recorded several decades ago when the planet was cooler. Current pollen limitation for some species in some habitats might underestimate historical levels.

Recuperación del funcionamiento hidrológico de ecosistemas de páramo en colombia / Rehabilitation of hydrological functioning of páramo ecosystems in colombia

Los páramos son ecosistemas que se caracterizan por una alta humedad relativa, alta frecuencia de niebla y por tener una vegetación arbustiva y herbácea, adaptada a las condiciones de alta montaña. En condiciones naturales estos ecosistemas presentan una oferta hídrica alta, entre otros servicios ecosistémicos; sin embargo, esto cambia cuando son degradados. A pesar de su importancia son ecosistemas que han sido modificados por el hombre, la mayoría aún sin haber sido estudiados. Este documento presenta los resultados de una investigación realizada en tres páramos en Colombia, en la cual, se evalúa su funcionamiento hidrológico y la capacidad de recuperación, una vez han sido alterados; para esto, se estudió el clima, la hidrología y los suelos. Los resultados indican que estos ecosistemas tienen condiciones climáticas desiguales, que determinan su rendimiento y regulación hídrica; con diferencias en las propiedades hidrofísicas del suelo y contenido de materia orgánica, lo que determina diferencias en su capacidad para retener la humedad y la disponibilidad de agua para las plantas. Estos resultados indican que los páramos, con un grado bajo de disturbio, presentan un alto rendimiento y buena regulación hídrica; pero igual que los páramos intervenidos, recuperan el estado natural de las propiedades del suelo y, consecuentemente, su funcionamiento hidrológico, aún en pocas décadas.

Páramos are equatorial alpine ecosystems characterized by a high air humidity, frequency of fog and the presence of shrub and herbaceous vegetation adapted to the specific equatorial alpine conditions. Under natural conditions these ecosystems present a high water yield, among other ecosystem services, however, this changes when they are degraded. Despite their importance, they are ecosystems that have been modified by man, most of them even without having been studied. This paper presents the results of a hydrological research carried out in three páramos in Colombia, which evaluates their hydrological functioning and their capacity for recovery once they are altered. Therefore, we studied their climate, hydrology, and soils properties. Results indicate that these ecosystems have different climatic conditions, which determine their water yield and water regulation. Differences in the hydro-physical properties of soils and organic matter content, which determine differences in their capacity to retain water and on the magnitude of the water available for plants. These results indicate that undisturbed páramos or with a low degree of disturbance present high water yield and good water regulation; and intervened páramos can recover the natural conditions of soil properties, and consequently their hydrological functioning, even in a few decades.

Drought increases the freezing resistance of high-elevation plants of the Central Chilean Andes.

Freezing temperatures and summer droughts shape plant life in Mediterranean high-elevation habitats. Thus, the impacts of climate change on plant survival for these species could be quite different to those from mesic mountains. We exposed 12 alpine species to experimental irrigation and warming in the Central Chilean Andes to assess whether irrigation decreases freezing resistance, irrigation influences freezing resistance when plants are exposed to warming, and to assess the relative importance of irrigation and temperature in controlling plant freezing resistance. Freezing resistance was determined as the freezing temperature that produced 50 % photoinactivation [lethal temperature (LT50)] and the freezing point (FP). In seven out of 12 high-Andean species, LT50 of drought-exposed plants was on average 3.5 K lower than that of irrigated plants. In contrast, most species did not show differences in FP. Warming changed the effect of irrigation on LT50. Depending on species, warming was found to have (1) no effect, (2) to increase, or (3) to decrease the irrigation effect on LT50. However, the effect size of irrigation on LT50 was greater than that of warming for almost all species. The effect of irrigation on FP was slightly changed by warming and was sometimes in disagreement with LT50 responses. Our data show that drought increases the freezing resistance of high-Andean plant species as a general plant response. Although freezing resistance increases depended on species-specific traits, our results show that warmer and moister growing seasons due to climate change will seriously threaten plant survival and persistence of these and other alpine species in dry mountains.