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

Knowledge arising from long-term research of variable retention harvesting in Tierra del Fuego: where do we go from here?

Nothofagus pumilio forests in Tierra del Fuego are the southernmost forests in the world, where extreme climate conditions represent a challenge to attain sustainable forest management. Retention forestry was proposed as an alternative to increase the species conservation in managed stands. Here, we synthetized results related to the implementation of a variable retention harvesting based on a combination of aggregate patches and dispersed retention during the last 18 years comparing with other silviculture proposals (e.g., shelterwood cuts) and control treatments (primary unmanaged forests). We summarized the results for (i) sawmill operations, (ii) timber yield, (iii) overstory stability, (iv) forest structure, (v) microclimate and natural cycles, (vi) natural regeneration dynamics (flowering, seeding, foraging, recruitment, growth, and mortality), and (vii) biodiversity (mammals, understory plants, mistletoes, birds, arthropods, mosses, lichens, and fungi). In general, aggregate patches maintained forest structure and micro-environmental variables, and slightly increased biodiversity and forest reproduction variables compared to unmanaged primary forests. On the contrary, dispersed retention decreased forest structure variables and greatly increased biodiversity (richness and abundance) when it was compared to unmanaged primary forests. Ecological conditions are influenced by variable retention harvesting, but direction and magnitude of the effect depend and differ according to retention types. Besides this, biodiversity taxa greatly differed among groups depending on retention types. In general, the species assemblages in aggregate patches were similar to those found in primary unmanaged forests, while they were significantly modified in the dispersed retention. This occurred due to (i) local extinction of some original species, (ii) the introduction of native species from the surrounding environments, or (iii) the invasion of exotic species. This silvicultural method has been a useful tool to conserve biodiversity and ecosystem functions, approaching to the balance between economy, ecology, and social requirements in the managed areas.EEA Santa CruzFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Rosas, Yamina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Toro Manríquez, Mónica D.R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Miller, Juan A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Cellini, Juan Manuel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Barrera, Marcelo Daniel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: 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: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; Argentin

Social media reveal visitors’ interest in flora and fauna species of a forest region

ABSTRACT Visitor interests can be crucial to understanding humans’ connectedness in nature. We analysed the relationship between people and flora and fauna species (native and exotic) through YouTube videos of a forest region (southern Patagonia) posted by visitors from different parts of the world. We characterised the species of flora and fauna observed by the visitors and calculated the time that appears in the videos as a proxy for their connectedness to biodiversity. The biodiversity observations were contrasted against visitors’ sociodemographic characteristics (age and gender) by the Van der Waerden test and multivariate analyses. We created a sociogram that showed connections among species through visitor links to these data. Our results reveal different degrees of relationship between species, where some exotic ones were more preferred than natives (Van der Waerden test p = <0.100). Differences in the linkage to the flora and fauna species were related to the age and gender of the visitors. Visitor interests are modulated by access to ecosystem types (e.g. forests) and species’ commonness/rarity and docility. Gender and age had less influence on the interests than expected, but it determined differential values on native and exotic diversity. Three groups of species emerged from the sociogram based on the visitor connectedness to flora and fauna species, evidencing high connections among native trees (Nothofagus spp.), exotic beavers (Castor canadensis), and native geese and ducks (e.g. Chloephaga picta). The novel approach utilised provides valuable data that can be used to test the influence of gender and age on the different biodiversity interests. This information has potential applications for nature conservation by detecting unsponsored biodiversity and ecosystem types that could be promoted, capturing the visitor interests, and improving the offer of visitor activities according to gender/age observations

Relationships among livestock, structure, and regeneration in Chilean Austral Macrozone temperate forests

A Macrozone is a socioecological region with shared geographic and demographic characteristics. Within the Chilean Austral Macrozone (43° to 56° SL), the native temperate forests serve as a crucial resource, offering multiple ecosystem services to local communities. These forests significantly support animal husbandry practices involving cattle, horses and sheep. However, introducing these exotic species affects natural regeneration and compromises their long-term sustainability. This study proposes a new classification of the temperate forests in the Chilean Austral Macrozone based on structure parameters and determine their relationships with animal husbandry and natural regeneration. Data were obtained from Chile's National Forest Inventory (NFI) (2001–2010), including 195 inventory plots (500 m2) with 21 tree species. We redefined the forest categories described in NFI according to the proportional basal area of each tree species at each plot. We used two levels of analysis: forest composition (Level 1), which includes general categories such as mono-specific (dominated by a single tree species), bi-specific (dominated by two tree species), and multi-specific forests (dominated by multiple tree species), and forest type (Level 2), which includes specific species (e.g., Nothofagus pumilio) or species groups (e.g., N. pumilio - N. dombeyi) with economic relevance. We evaluated the data using univariate and multivariate analyses. We found 18 forest types in the Austral Macrozone, in contrast to the three traditionally recognized forest types used in the NFI (e.g., lenga, evergreen, coihue de Magallanes). Livestock was observed in all forest types, where Nothofagus forests showed that regeneration in N. antarctica and N. pumilio were higher with livestock than without livestock breeding (Hedges' g > 0.51). The natural regeneration of the studied forests was influenced by animal husbandry, environmental variables (bioclimatic and topographic factors), and forest structure. Our data suggested the importance of using more forest types than the three classics to generate tools or recommendations that are more focused on the particularities of each one. The classification must be based on forest parameters obtained during NFI. The proposed forest type classification reflects the complexity and richness of the forests in a better way, which could improve forest management and the development of public policies related to climate change and sustainability. Finally, although livestock pressure was observed in all forest types, the impact over some areas (e.g., N. antarctica) needs special attention in the forest management and conservation planning for the Chilean Austral Macrozone

Conservation values of understory vascular plants in even- and uneven-aged Nothofagus antarctica forests

Usually, stands with aging trees are considered forests with higher conservation values, regardless their structural diversity and other functional attributes. Natural stands present a wide range of age structures, from even-aged stands growing at different development growth phases (e.g. CO = stands at initial or final optimum development growth phase, MD = stands at mature or decaying development growth phases) to uneven-aged stands with mixed development growth phases (e.g. UOG = stands combining mature or decaying development growth phases with initial or final optimum development growth phases, UMD = stands combining only mature and decaying development growth phases). The aim of this work was to compare richness and cover of understory vascular plants of even- and uneven-aged stands of Nothofagus antarctica (ñire) forests in Tierra del Fuego (Argentina), and relate these characteristics with abiotic, soil and forest structure variables. A total of 75 stands were sampled across the natural range distribution of the forests, where understory (point intercept method), forest structure (angle count sampling and eye-fish photos) and environmental (soil) variables were measured. 17 one-way ANOVAs were conducted using Tukey test at p  UOG > MD > CO (17–28 total, and 13–24 native species, respectively). Neither exotic species richness (4–5 species) nor understory cover significantly changed among treatments (total, dicots, ferns and bryophytes). However, monocots cover significantly differed among treatments (F = 3.9, p = 0.012), where UMD > MD > UOG > CO. Finally, indicator species cover for environmental degradation did not present significant differences (F = 2.1, p = 0.106), but they were positive related to forests growing in mature stages. We concluded that uneven-aged stands presented significantly higher conservation values compared to even-aged stands, where mature/decay stands have better conservation values than optimum growth development phases. These findings can be used for better silviculture practices that combine silvopastoral use and conservation strategies.EEA Santa CruzFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Rosas, Yamina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Cellini, Juan Manuel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Barrera, Marcelo Daniel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Toro Manríquez, Mónica D.R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Favoretti Bondar, Santiago. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Ambiente y Recursos Naturales; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: 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; Argentin

Beneficios e impactos de la promulgación de la ley N° 26.331, y factores de cambio que influyen sobre su implementación.

La Argentina posee una enorme diversidad de paisajes y gradientes ambientales que favorecen el mantenimiento de una gran biodiversidad, con características regionales y de alto valor de conservación. Sin embargo, la pérdida de cobertura forestal asociada a factores naturales y antrópicos, que ha variado con el paso de los años, constituye la principal amenaza para el mantenimiento de dicha biodiversidad. En este marco se promulgó la Ley n° 26.331 de Presupuestos Mínimos de Protección Ambiental de los Bosques Nativos. Este capítulo describe los contenidos de dicha Ley, sus alcances y el impacto que ha tenido a lo largo de estos últimos años. Se analizan también los cambios en las coberturas forestales, discriminadas por provincias y prioridad de uso de los ordenamientos territoriales de los bosques nativos. Estos cambios (pérdidas y ganancias) se cuantificaron mediante imágenes satelitales, y se correlacionaron con la promulgación de la ley, así como las legislaciones provinciales asociadas Asimismo, se discute el uso de los pagos realizados en el marco de dicha legislación, y su impacto sobre el manejo y la conservación de los bosques nativos. Finalmente, se analizan las sinergias y conflictos de las actividades productivas que influyen en la persistencia de los bosques nativos, a través de análisis multivariados. Estos análisis permiten dimensionar la influencia de cada variable analizada sobre la pérdida de la cobertura forestal para cada provincia en general, y en particular de la evolución de los cultivos de soja. En general, la pérdida de cobertura forestal está asociada a la densidad poblacional, la actividad agropecuaria y la ganadería. Este capítulo permite dimensionar los impactos producidos por los conflictos que existen en el uso potencial del suelo, entre el bosque nativo y otras actividades productivas, así como cuantificar en forma efectiva los perjuicios y beneficios de la implementación de la ley n˚ 26.331. Asimismo, pone en evidencia la necesidad de promover programas de pago por prestación de servicios ambientales en el largo plazo. Se desprende la necesidad de establecer políticas regionales asociadas a los factores vinculados con la pérdida de cobertura forestal, en la búsqueda de alternativas de manejo sostenible que combinen propuestas económicas y de conservación.EEA Santa CruzFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas (CADIC); Argentina.Fil: Schlichter, Tomás Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Dirección Nacional; Argentina.Fil: Schlichter, Tomás Miguel. Universidad de Buenos Aires- Facultad de Agronomía; Argentina.Fil: Gowda, Juan H. Consejo Nacional de Investigaciones Científicas y Técnicas. Laboratorio de Ecotono; Argentina.Fil: Gowda, Juan H. Universidad Nacional del Comahue; Argentina.Fil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas (CADIC); ArgentinaFil: Toro Manríquez, Mónica, D.R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas (CADIC); Argentina.Fil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas (CADIC). Ushuaia, Tierra del Fuego; Argentina.Fil: Manghi, Eduardo. Ministerio de Ambiente y Desarrollo Sustentable de Nación (MAyDS). Dirección de Bosques. Secretaría de Política Ambiental en Recursos Naturales; Argentina.Fil: Matteucci, Silvia D. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Matteucci, Silvia D. Universidad de Buenos Aires. Facultad de Arquitectura, Diseño y Urbanismo. Grupo de Ecología de Paisajes y Medio Ambiente; Argentina.Fil: Cellini, Juan Manuel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina