Análisis de los micrositios de regeneración para Nothofagus pumilio en sectores perturbados y no perturbados por el efecto del Castor canadensis en Tierra del Fuego, Chile

Castor canadensis afecta a bosques de Nothofagus en Tierra del Fuego, por construcción de castoreras e inundación de bosques. Luego de la eliminación de castores, el sector inundado cambia a una pradera abierta. El objetivo es analizar el establecimiento de plantas de regeneración de N. pumilio (lenga) respecto a micrositios en pradera de castor y bosque no afectado por castor. La investigación se desarrolló en una castorera abandonada, en el sector de Vicuña, Tierra del Fuego (54º8?S, 68º42?O). En la vecindad de la castorera se encuentra un bosque de lenga coetáneo (390 árboles/ha, 93,5 m2/ha). En la pradera de castor y en el bosque se instalaron sistemáticamente 121 y 88 parcelas para estimación de cobertura de cada uno de los sustratos presentes. En las parcelas se identificaron los micrositios que están siendo utilizados por las plantas de regeneración de lenga. Las plantas fueron caracterizadas y se identificó la presencia de ramoneo por Lama guanicoe (guanaco). Los resultados establecen que los principales sustratos en la pradera corresponden a conjuntos de plantas herbáceas (47,9% de cobertura) y madera en descomposición grado 1 (12,6%). En el bosque el sustrato del suelo está cubierto mayoritariamente por plantas herbáceas (30,7%) y hojarasca (13,7%). En la pradera se encontraron 1,9 plantas de regeneración por m2, estableciéndose mayoritariamente sobre plantas herbáceas (entre 52,2 y 55,6% de las plantas). En el bosque de lenga se encontraron 10,0 plantas de regeneración por m2, las que se encontraban creciendo mayoritariamente sobre madera en descomposición grado 3 (39,7 a 44,6%). El 81,5% de las plantas se encuentran ramoneadas por guanaco en la pradera de castor y solamente el 15,9% en el bosque. Actividades de restauración de castoreras abandonadas deberían considerar el establecimiento de plantas de regeneración en micrositios que son utilizados naturalmente por lenga, además de aislar la presencia de guanaco.Fil: Toro Manríquez, Mónica del Rosario. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Promis Baeza, Alvaro Andres. Universidad de Chile; ChileVI Congreso Chileno de Ciencias ForestalesTemucoChileUniversidad de La FronteraSociedad Chilena de Ciencias Forestale

Canopy composition and site are indicative of mineral soil conditions in Patagonian mixed Nothofagus forests

Key message: Canopy composition in mixed Patagonian Nothofagus forests has an impact on soil properties like cationic exchange capacity and pH, while most soil variables changed with site [P, cation exchange capacity (CEC), soil moisture (SM), resistance to penetration (R)]. Site conditions and canopy composition need be considered together to better understand the distribution of Nothofagus species.Context: Forests can influence soil development, changing main soil properties by several mechanisms, but this has never been investigated in mixed Nothofagus forests. Such influences can be strongly variable depending on local site conditions, and the interactions between both factors need to be clearly established.Aims: To reveal the effect on physical and chemical mineral soil properties in mixed Nothofagus forests of canopy composition and their interactions with site conditions.Methods: Two sites and threemixed forest types, with different proportion of deciduous-evergreen,were selected in coastal andmountain sites. We evaluated forest structure, litterfall and physico-chemical properties of mineral soil (N= 60), and analyzed these factors with general linear models and multivariate statistics [multi-response permutation procedure (MRPP), principal component analyses (PCA)].Results: Basal area and litterfall were significantly influenced by forest type × sites. CEC and pH value varied among forests types and sites, but sites also influenced other variables (P, SM, R). Multivariate analyses reveals a much stronger effect of site conditions than that of species mixture.Conclusion: Forest soil studies must consider environmental factors on different spatial scale and canopy species composition to better understand their influence on soil dynamics in mixed Nothofagus forests.Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Promis, Álvaro. Universidad de Chile; Chil

Mapping the status of the North American beaver invasion in the Tierra del Fuego archipelago

Quantifying the presence and environmental impact of invasive species is the starting point for research on management and nature conservation. North American beavers (Castor canadensis) were introduced to Argentina from Canada in 1946, and the species has been identified as a major agent of environmental change in the Tierra del Fuego archipelago in the Anthropocene. We studied the invasion status (distribution and density) of beavers through analyses of the dam densities in the Tierra del Fuego landscapes. We identified beaver dams with a GIS using visual interpretation of high-resolution aerial imagery from Microsoft Bing, Google Earth and HERE and related them to natural environmental gradients. These factors comprised geographic (vegetation zones and distance to streams), climatic (temperature, precipitation, evapotranspiration and net primary productivity) and topographic (elevation and slope) data. The datasets (dams and factors) were combined, and the data from the different zonation classes were subsequently compared using ANOVAs and Tukey’s mean comparison tests. Deviations from the mean density (x mean density—x total mean density) were calculated to visualize the deviations for the studied factors. The datasets were also evaluated using principal component analyses (PCA). Our results showed a total of 206,203 beaver dams (100,951 in Argentina and 105,252 in Chile) in the study area (73,000 km2). The main island of Tierra del Fuego presented a greater degree of invasion (73.6% of the total study area) than the rest of the archipelago, especially in areas covered by mixed-evergreen and deciduous forests. The studied geographic, climatic and topographic factors showed positive trends (higher beaver preference) with beaver spread, which were all significant (p <0.05) when compared across the landscape. Although beavers are flexible in their habitat use, our empirical records showed that they had marked preferences and were positively influenced by the most productive forests. Here, we describe a scientific panorama that identified the drivers of species invasion based on satellite data and the available ecological datasets. The identification of such drivers could be useful for developing new tools for management and/or control strategies of the beavers in the Tierra del Fuego archipelago.Fil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Miller, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Manejo de la quema de pastizales de sabana inundable: una mirada del pueblo originario Saliva en Colombia

El conocimiento histórico que se tiene de las quemas por parte de los pueblos originarios contribuye a entender el papel que cumple el fuego en ecosistemas naturales tropicales y templados. El objetivo de este trabajo fue describir el manejo y la importancia de la quema para el pueblo originario Sáliva en el ecosistema de sabana inundable de Colombia. A través de entrevistas semiestructuradas, cartografía social y calendarios anuales se obtuvieron las apreciaciones que tienen los Sáliva del fuego en pastizales nativos. La percepción generalizada de que las quemas son perjudiciales se ha insertado en su imaginario, pero se conserva el concepto del fuego como un factor determinante que afecta la sucesión vegetal y su uso mantiene el paisaje de sabana. Antes de ser aculturizados por los jesuitas en costumbres, religión y ganadería bovina, los Sáliva aplicaban fuego para facilitar la caza y los desplazamientos, pero su sometimiento al manejo del ganado cambió la concepción de su aplicación. Se concluyó que en la actualidad los Sáliva no aplican fuego indiscriminadamente, sino que hacen un manejo estratégico con fines agropecuarios y de prevención de incendios y rescatan saberes tradicionales del conocimiento ecosistémico.The historical knowledge about the management of burnings by native peoples allows us to understand the role played by fire in natural tropical and temperate ecosystems. The objective of this work was to describe the management and importance of burning for the native Sáliva people in the flooded savanna ecosystem of Colombia. The assessment that the Sáliva have of fire in native grasslands was obtained through semi-structured interviews, social cartography and annual calendars. The generalized opinion that burnings are harmful is firmly established in their imaginary, but the concept of fire remains as a determining factor affecting plant succession and its use maintains the savanna landscape. Before being acculturized by the Jesuits in customs, religion and cattle rearing, the Sáliva applied fire to facilitate hunting and movement, but their subjection to cattle rearing changed the conception of its application. It is concluded that, at present, the Sáliva do not apply fire indiscriminately; instead, they manage it strategically for agricultural purposes and also rescue traditional knowledge of the ecosystem.Fil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Briggite Baptiste. Instituto de Investigación Alexander Von Humboldt; ColombiaFil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Hugoberto Huertas Ramírez. Fundacion Horizonte Verde; Colombi

A pivotal nutritional potential of understory vascular plants in Patagonian forests

Los bosques nativos pueden sustentar a herbívoros domésticos y silvestres, pero rara vez se explora su potencial nutricional de las plantas vasculares del sotobosque. Analizamos la composición de las especies de plantas del sotobosque y sus componentes bioquímicos para revelar el potencial nutricional de los tipos de bosque (caducifolio, siempreverde, mixto) y sus tierras abiertas asociadas (por ejemplo, pastizales en bosques) en la Patagonia Norte. Propusimos un enfoque que combina nuestros datos (por ejemplo, composición de las plantas, frecuencia de aparición) con investigación bibliográfica (por ejemplo, base de datos Scopus) para desarrollar nuestros hallazgos. Los datos se evaluaron utilizando análisis estadísticos descriptivos y análisis multivariados . Este estudio presenta los valores nutricionales de las 20 especies fundamentales bajo examen. Los resultados resaltan el impacto significativo de las familias taxonómicas en los perfiles nutricionales, donde las especies que presentaron la frecuencia de ocurrencia más relevante: las hierbas T. officinale (60.4 % de la frecuencia de ocurrencia total-TOF) y T. repens (47.9 % TOF), la graminoide H. lanatus (58 % TOF) y el helecho B. penna marina (44.4 % TOF). Los análisis multivariados mostraron que los dos primeros ejes del PCA explicaron el 76.1 % ( p = 0.001) y el 10.5 % ( p = 1.000) de la variación del tipo de bosque, siendo los bosques de ñire y los terrenos abiertos los que presentaron la mayor cobertura vegetal palatable. Los ejes bioquímicos del PCA explicaron el 52.1 % ( p = 0.024) y el 22.5 % ( p = 0.874) de la variación, distinguiendo especies por contenido proteico y componentes estructurales. Los bosques caducifolios exhibieron la mayor cobertura de plantas palatables, mientras que las plantas objetivo con baja palatabilidad y alta cobertura se encontraron predominantemente en los tipos de bosques siempreverdes. La presencia confirmada de especies fundamentales en todos los tipos de bosques y tierras abiertas subraya su potencial nutricional, caracterizado por materia seca altamente digestible, proteína cruda, nutrientes no nitrogenados altamente digestibles y valor alimenticio relativo. Considerando su amplia distribución y factores nutricionales, las plantas nativas y no nativas merecen atención debido a su potencial nutricional fundamental.Native forests can support wild and domestic herbivores, but their nutritional potential of understory vascular plants is rarely explored. We analysed the composition of understory plant species and their biochemical components to reveal the nutritional potential of forest types (deciduous, evergreen, mixed) and their associated open-lands (e.g. grasslands in forestlands) in Northern Patagonia. We proposed an approach combining our data (e.g. plant composition, occurrence frequency) with bibliographic research (e.g. Scopus database) to develop our findings. Data were evaluated using descriptive statistical analyses and multivariate analyses. This study presents the nutritional values for the 20 pivotal species under examination. The results highlight the significant impact of taxonomic families on nutritional profiles, where the species that presented the most relevant occurrence frequency: the herbs T. officinale (60.4 % of total occurrence frequency-TOF) and T. repens (47.9 % TOF), the graminoid H. lanatus (58 % TOF), and the fern B. penna marina (44.4 % TOF). Multivariate analyses showed that the first two PCA axes explained 76.1 % (p = 0.001) and 10.5 % (p = 1.000) of forest type variation, with ñire forests and open-lands having the highest palatable plant coverage. Biochemical PCA axes explained 52.1 % (p = 0.024) and 22.5 % (p = 0.874) of the variation, distinguishing species by protein content and structural components. The deciduous forests exhibited the highest coverage of palatable plants, while target plants with low palatability and high coverage were predominantly found in evergreen forest types. The confirmed presence of pivotal species across forest types and open-lands underscores its nutritional potential, characterised by highly digestible dry matter, crude protein, highly digestible non-nitrogenous nutrients, and relative feed value. Considering their widespread distribution and nutritional factors, the native and non-native plants merit attention due to their pivotal nutritional potential.Fil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigacion En Ecosistemas de la Patagonia;Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigacion En Ecosistemas de la Patagonia;Fil: Villagrán, Santiago. Centro de Investigacion En Ecosistemas de la Patagonia;Fil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Llobat, Lola. Universidad Cardenal Herrera; EspañaFil: Marín García, Pablo Jesus. Universidad Cardenal Herrera; Españ

Assessing Socio-ecological Systems Using Social Media Data: An Approach for Forested Landscapes in Tierra del Fuego, Argentina

The purpose of this study was to analyse how visitors valued a socio-ecological system through the use of social media data. We gathered YouTube´s videos of Ushuaia city and its surrounding forested landscapes (Tierra del Fuego, Argentina) posted between 2010 and 2020. We used the screen time (seconds) of each video to compare the value of visitors on biophysical, cultural, and biodiversity attributes of the studied socio-ecological system. Each of the visitors registered differently the same attribute (e.g. mountains, forests, signposts, fauna, among others), therefore we assessed the time each visitor spend on any attribute, that was calculated considering the focus and scale through which it was observed. Based on our analyses, we found a diversity of attributes with different valuation data for each visitor. Attributes were classified as biophysical, cultural, and biodiversity variables, and the origin of the visitors (e.g. regions of the world) was also evaluated, with descriptive and multivariate analyses. Results indicated that visitors give more value to biophysical and cultural attributes compared to local biodiversity. These outputs highlight the need to explore and implement alternative methods to assess the socio-ecological values to achieve management objectives, and to include socio-ecological attributes in the study area as key indicators to create better tools and solutions for conservation issues. In this context, we provide a new insight into how visitors can appreciate different socio-ecological values.Fil: Huertas Herrera, Alejandro. Universidad de Magallanes; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Toro Manríquez, Mónica. Universidad de Magallanes; ChileFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lorenzo, Cristian A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Suitable conditions for natural regeneration in variable retention harvesting of southern Patagonian Nothofagus pumilio forests

Background: Variable retention (aggregated and dispersed retention) harvesting proposed for Nothofagus pumilio was designed for timber purposes and biodiversity conservation. Harvesting by opening canopy generates different microenvironments and creates contrasting conditions for seedling establishment, growth, and eco-physiology performance due to synergies (positives or negatives) with biotic and abiotic factors. This study evaluated the regeneration in different microenvironment conditions within managed stands during 5 years after harvesting. Remnant forest structure after harvesting and different microenvironments were characterized in managed stands, where 105 regeneration plots were measured (3 stands × 7 microenvironments × 5 replicas). We characterized the seedling bank, as well as growth and ecophysiology performance of the regeneration. Univariate and multivariate analyses were conducted for the comparisons. Results: Microenvironments offered different environmental conditions for natural regeneration (soil moisture and light availability). Seedling under debris and dicot plants showed better eco-physiological performance, establishment, and growth than plants growing under monocots or located in the dispersed retention without the protection of other understory plants. The most unfavorable microenvironment conditions were high canopy cover of remnant trees (inside the aggregates or close to trees in the dispersed retention) and heavily impacted areas (skidder extraction roads). Conclusions: Favorable microenvironments in the harvested areas will improve the natural recruitment, growth, and eco-physiology performance of the natural regeneration after harvesting. It is necessary to develop new silvicultural practices that decrease the unfavorable microenvironments (e.g., road density or excessive woody accumulation), to assure the success of the proposed silvicultural method.EEA Santa CruzFil: Toro Manríquez, Mónica D.R. Centro Austral de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Cellini, Juan Manuel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Lencinas, María Vanessa. Centro Austral de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Universidad Nacional de la Patagonia Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Peña Rojas, Karen A. Universidad de Chile. Facultad de Ciencias Forestales y de Conservación de la Naturaleza. Departamento de Silvicultura y Conservación de la Naturaleza; ChileFil: Martínez Pastur, Guillermo José. Centro Austral de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Rehabilitation of Nothofagus pumilio forests in Chilean Patagonia: can fencing and planting season effectively protect against exotic European hare browsing?

In forests affected by heavy fires and continuous grazing of exotic herbivorous mammal species, Nothofagus pumilio (lenga) cannot recover naturally. The main factors that hinder the natural recovery of these forests and the feasibility of native tree plantations are the exotic herbivorous pressure, like that produced by Lepus europaeus (European hare), and the environment degradation degree by anthropic disturbances. The objective of this study was to evaluate different plantation efforts to recover N. pumilio forests degraded by fires in Chilean Patagonia. The plantation actions also included wire fences for sapling protection in 100 ha, where 60 ha were established during autumn (May 2012), and 40 ha were established during spring (October 2012). In March 2013 we recorded the height annual growth (cm year−1), the section browsed at each sapling, the modification of plant form (number of new branches), and the vigor expression. We evaluated the data using one- and two-way ANOVAs, Cohen's d effect size, and chi-square analyses. We measured a total of 872 plants, where 42% presented damages caused by European hare browsing. These results indicated that the wire fences were not completely useful to stop the damage on saplings (Cohen's d effect size= <0.2). We also found that autumn plantations were more susceptible to damage than those established during spring. European hares predominantly browsed on a particular sapling section: the apical buds. As a consequence, the browsed saplings had lower height growth than undamaged ones. These outputs highlight the need to explore and implement alternative actions for the rehabilitation of these degraded deciduous forests, to achieve the objectives of sustainable management or to recover the natural ecosystem functions.Fil: Huertas Herrera, Alejandro. Ulterarius Consultores Ambientales y Científicos Ltda; Chile. Universidad de Magallanes; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Promis Baeza, Alvaro Andres. Universidad de Chile; ChileFil: Toro Manríquez, Mónica del Rosario. Universidad de Magallanes; Chile. Ulterarius Consultores Ambientales y Científicos Ltda; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Río, Matias. Fundación Reforestemos Patagonia; Chil

Changes in vegetation of flooded savannas subject to cattle grazing and fire in plains of Colombia

Cattle grazing and fire are common types of management on natural ecosystems, generating several threats to the conservation of native vegetation (e.g., changes in species richness, cover, and abundance, mainly of bovine-palatable species). In this work, we analysed the response of the structure and composition of vegetation managed with different cattle stocking rates and fire in the savanna ecosystems of Colombia. The study was located in the eastern area of the Llanos region, where savannas were subjected to grazing and burning. Regarding grazing, we classified the area according to the cattle stocking rate (Bos indicus ~300 kg): NG = non-grazed, LS = low stocking rate (0.5 ind ha-1 yr-1), and HS = high stocking rate (1.0 ind ha-1 yr-1). Controlled artificial burning was applied in all the area at the beginning of the study, and surveys were conducted in the same plots at pre-burn (t0) and four post-burn times (t1, t2, t3, t4), at 15, 45, 75 and 105 days after burning. Vegetation composition (species list, life-form, palatability) and structure (bare soil and vascular plant ground covers, species height and richness) were recorded at each sampling. Data were compared through ANOVAs and multivariate analyses. We found 53 species in total: 26 in the pre-burn treatment and 44 in the post-burn treatments, detecting an increase of 18 species considering all treatments. Seven natives and two exotic species represented the dominant cover (>50%). LS and HS had the highest number of palatable species in t0 (seven species) compared with NG (two species), but this became similar after burning (14 species in NG, 12 in LS, and 11 in HS). ANOVAs and multivariate analyses showed that plant assemblages were significantly different according to the grazing treatment, and more homogeneous in pre-burn than in post-burn periods. Cattle grazing favored higher covers of dominant palatable species (e.g., Axonopus purpusii) compared with NG, but many native species with high palatability only recovered within the system after burning. In the context of the current management proposals, the search for new alternatives other than intensive cattle grazing and burning is needed to reconcile human production activities, international commitments against climate change and biodiversity conservation in the savanna landscapes.Fil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baptiste Ballera, Brigitte L.G.. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt; ColombiaFil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Huerta Ramírez, Hugoberto. Fundación Horizonte Verde; Colombi

Forest canopy-cover composition and landscape influence on bryophyte communities in Nothofagus forests of southern Patagonia

Bryophytes (liverworts, mosses and hornworts) are one of the most diverse plant groups worldwide but one of the least studied in temperate forests from an ecological perspective. In comparison to vascular plants, bryophytes have a broader distribution and a longer altitudinal gradient, and their influence on the landscape is poorly understood. The objective was to evaluate environmental drivers that can influence bryophyte cover, richness, diversity, and nestedness in different forest canopy compositions in two typical landscapes across the natural distribution of bryophytes in Tierra del Fuego (Argentina). Three natural Nothofagus forest types (pure deciduous, pure evergreen, and mixed deciduous-evergreen) in two landscapes (coasts 400 m.a.s.l.) were selected (N = 60 plots). In each plot, we established one transect (10 m length) to measure bryophyte cover (pointintercept method). Data were evaluated using generalized linear mixed models and multivariate analyses. The studied environmental drivers were mainly explained by the microclimate, with higher effective annual precipitation and relative air humidity in the coastal forests and higher soil moisture in the mountain forests. Greater liverwort richness was found in evergreen forests at the mountain (9 species) than at the coastal, while mosses showed higher richness in mixed deciduous-evergreen forests at the coastal (11 species) than at the mountain. However, the expected richness according to the rarefaction/extrapolation curves suggested that it is possible to record additional species, except for liverworts in pure deciduous forests on the coasts. Similarities and differences among the studied forest types and among plots of the same forest type and landscape were detected. These differences in the studied indexes (similarity that varied between 0 and 1) ranged from 0.09- 0.48 for liverworts and 0.05-0.65 for mosses. Moreover, these results indicated that pure evergreen and mixed deciduous-evergreen forests presented higher moss cover (10.7% and 10.0%, respectively), mainly in the mountains than on the coast. These outputs highlight the need to explore differences at greater altitudinal ranges to achieve sustainability objectives conservation planning for bryophytes in southernmost forests.Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Ardiles, Víctor. Museo Nacional de Historia Natural de Santiago; ChileFil: Promis, Álvaro. Universidad de Chile; ChileFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin