Background The nationally determined contribution(NDC)presented by Argentina within the framework of the Paris Agreement is aligned with the decisions made in the context of the United Nations Framework Conven-tion on...Background The nationally determined contribution(NDC)presented by Argentina within the framework of the Paris Agreement is aligned with the decisions made in the context of the United Nations Framework Conven-tion on Climate Change(UNFCCC)on the reduction of emissions derived from deforestation and forest degradation,as well as forest carbon conservation(REDD+).In addition,climate change constitutes one of the greatest threats to forest biodiversity and ecosystem services.However,the soil organic carbon(SOC)stocks of native forests have not been incorporated into the Forest Reference Emission Levels calculations and for conservation planning under cli-mate variability due to a lack of information.The objectives of this study were:(i)to model SOC stocks to 30 cm of native forests at a national scale using climatic,topographic and vegetation as predictor variables,and(ii)to relate SOC stocks with spatial–temporal remotely sensed indices to determine biodiversity conservation concerns due to threats from high inter-annual climate variability.Methods We used 1040 forest soil samples(0–30 cm)to generate spatially explicit estimates of SOC native forests in Argentina at a spatial resolution of approximately 200 m.We selected 52 potential predictive environmental covari-ates,which represent key factors for the spatial distribution of SOC.All covariate maps were uploaded to the Google Earth Engine cloud-based computing platform for subsequent modelling.To determine the biodiversity threats from high inter-annual climate variability,we employed the spatial–temporal satellite-derived indices based on Enhanced Vegetation Index(EVI)and land surface temperature(LST)images from Landsat imagery.Results SOC model(0–30 cm depth)prediction accounted for 69%of the variation of this soil property across the whole native forest coverage in Argentina.Total mean SOC stock reached 2.81 Pg C(2.71–2.84 Pg C with a probability of 90%)for a total area of 460,790 km^(2),where Chaco forests represented 58.4%of total SOC stored,followed by Andean Patagonian forests(16.7%)and Espinal forests(10.0%).SOC stock model was fitted as a function of regional climate,which greatly influenced forest ecosystems,including precipitation(annual mean precipitation and precipitation of warmest quarter)and temperature(day land surface temperature,seasonality,maximum temper-ature of warmest month,month of maximum temperature,night land surface temperature,and monthly minimum temperature).Biodiversity was influenced by the SOC levels and the forest regions.Conclusions In the framework of the Kyoto Protocol and REDD+,information derived in the present work from the estimate of SOC in native forests can be incorporated into the annual National Inventory Report of Argentina to assist forest management proposals.It also gives insight into how native forests can be more resilient to reduce the impact of biodiversity loss.展开更多
Background Forest ecosystems undergo significant transformations due to harvesting and climate fluctuations,emphasizing the critical role of seeding in natural regeneration and long-term structural preservation.Climat...Background Forest ecosystems undergo significant transformations due to harvesting and climate fluctuations,emphasizing the critical role of seeding in natural regeneration and long-term structural preservation.Climate change further amplifies these dynamics,affecting phenology across species and regions.In Tierra del Fuego(Argentina),Nothofagus pumilio(lenga)forests represent the most important timber resource,and it is managed through different silvicultural strategies.This species demonstrates notable post-disturbance regeneration,yet seed fall exhibits signifi-cant variability,leading to variations in seed quality(e.g.,viability).This study aims to assess fluctuations in N.pumilio seed quality,determine how it varies concerning forest management strategies,annual productivity,and the co-occurrence of climatic phenomena including El Ni?o-Southern Oscillation(ENSO)and the Southern Annular Mode(SAM).Results Viable seeds represented 18.4%of the total,notably higher in unharvested than in managed areas.Con-versely,empty seeds were more prevalent in harvested areas(>75%).Seed quality exhibited significant differences across silvicultural treatments,except for insect-predated seeds,which had similar proportions across all areas,though dispersed retention showed higher predation.When considering years with varying production levels,high-production years favoured full and viable seeds,particularly in unharvested forests and aggregated retention,while low-production years saw reduced viability across all treatments.Quadratic models revealed that viability increased with seed production,where unharvested forests achieved the highest values.Climate variability influenced seed proportions,where ENSO+/SAM+promoting more full and viable seeds,while ENSO–/SAM+favoured non-predated seeds,especially in unharvested stands.Conclusions Seed quality varies among treatments and years with different levels of seeding.Variations in seed qual-ity,linked to climatic events,influence seed viability.Seed quality plays a critical role in forest regeneration,ensuring a seedling bank for harvested stands to face climate variability.These findings are relevant for forest management and ecosystem services,considering the increasing climate variability and extreme events.Understanding these influ-ences is crucial for Nothofagus pumilio forests'sustainability and global forest adaptation strategies.展开更多
Background:Biodiversity supports multiple ecosystem services,whereas species loss endangers the provision of many services and affects ecosystem resilience and resistance capacity.The increase of remote sensing techni...Background:Biodiversity supports multiple ecosystem services,whereas species loss endangers the provision of many services and affects ecosystem resilience and resistance capacity.The increase of remote sensing techniques allows to estimate biodiversity and ecosystem services supply at the landscape level in areas with low available data(e.g.Southern Patagonia).This paper evaluates the potential biodiversity and how it links with ecosystem services,based on vascular plant species across eight ecological areas.We also evaluated the habitat plant requirements and their relation with natural gradients.A total of 977 plots were used to develop habitat suitability maps based on an environmental niche factor analysis of 15 more important indicator species for each ecological area(n=53 species)using 40 explanatory variables.Finally,these maps were combined into a single potential biodiversity map,which was linked with environmental variables and ecosystem services supply.For comparisons,data were extracted and compared through analyses of variance.Results:The plant habitat requirements varied greatly among the different ecological areas,and it was possible to define groups according to its specialization and marginality indexes.The potential biodiversity map allowed us to detect coldspots in the western mountains and hotspots in southern and eastern areas.Higher biodiversity was associated to higher temperatures and normalized difference vegetation index,while lower biodiversity was related to elevation and rainfall.Potential biodiversity was closely associated with supporting and provisioning ecosystem services in shrublands and grasslands in the humid steppe,while the lowest values were related to cultural ecosystem services in Nothofagus forests.Conclusions:The present study showed that plant species present remarkable differences in spatial distributions and ecological requirements,being a useful proxy for potential biodiversity modelling.Potential biodiversity values change across ecological areas allowing to identify hotspots and coldspots,a useful tool for landscape management and conservation strategies.In addition,links with ecosystem services detect potential synergies and trade-offs,where areas with the lowest potential biodiversity are related to cultural ecosystem services(e.g.aesthetic values)and areas with the greatest potential biodiversity showed threats related to productive activities(e.g.livestock).展开更多
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 a...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.展开更多
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 differe...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.展开更多
Background It is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above...Background It is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above-and below-ground carbon balance in forest ecosystems.In this context,forest carbon management has gained more attention among managers and policy-makers during recent years.The aim of this study was to determine carbon pool dynamics in different forest ecosystem components after variable retention harvesting(VRH)to characterize the ecological stability and quantify the recovery rate through the years-after-harvesting(YAH).Methods Carbon pool compartmentalization of 14 different components was determined in 60 harvested and primary unmanaged forests during the first 18 YAH in Tierra del Fuego(Argentina).We compared them using uni-and multi-variate methods,relativizing the outputs with primary unmanaged forests.Results We determined the effectiveness to retain carbon components in post-harvested stands under different retention strategies(aggregated vs.dispersed).The balance among carbon pool components changed between managed and unmanaged stands across the YAH,and was directly related to the impact magnitude.Aggregated retention improved the ecological stability of the harvested areas,where the below-ground components were more stable than the above-ground components.The recovery rate was directly related to the post-harvesting natural dynamics of the stands.The studied period was not enough to fully recover the C levels of primary unmanaged for-ests,but VRH showed advantages to increase the C pools in the managed stands.Conclusions Promoting VRH can improve sustainable forestry at the landscape level and in the long term,generating positive synergies with biodiversity and the provision of ecosystem services.This study provides important new insights into forest carbon management,in particular to setting standards in carbon projects and sets the groundwork for analysing the economics of the mentioned harvesting systems.展开更多
基金Determinación del carbono orgánico en los suelos de los Bosques Nativos de Argentina.Apoyo para la Preparación de REDD+en el marco del Fondo Cooperativo para el Carbono de los Bosques(N°TF019086.RESOL-2021-17-APN-MAD)
文摘Background The nationally determined contribution(NDC)presented by Argentina within the framework of the Paris Agreement is aligned with the decisions made in the context of the United Nations Framework Conven-tion on Climate Change(UNFCCC)on the reduction of emissions derived from deforestation and forest degradation,as well as forest carbon conservation(REDD+).In addition,climate change constitutes one of the greatest threats to forest biodiversity and ecosystem services.However,the soil organic carbon(SOC)stocks of native forests have not been incorporated into the Forest Reference Emission Levels calculations and for conservation planning under cli-mate variability due to a lack of information.The objectives of this study were:(i)to model SOC stocks to 30 cm of native forests at a national scale using climatic,topographic and vegetation as predictor variables,and(ii)to relate SOC stocks with spatial–temporal remotely sensed indices to determine biodiversity conservation concerns due to threats from high inter-annual climate variability.Methods We used 1040 forest soil samples(0–30 cm)to generate spatially explicit estimates of SOC native forests in Argentina at a spatial resolution of approximately 200 m.We selected 52 potential predictive environmental covari-ates,which represent key factors for the spatial distribution of SOC.All covariate maps were uploaded to the Google Earth Engine cloud-based computing platform for subsequent modelling.To determine the biodiversity threats from high inter-annual climate variability,we employed the spatial–temporal satellite-derived indices based on Enhanced Vegetation Index(EVI)and land surface temperature(LST)images from Landsat imagery.Results SOC model(0–30 cm depth)prediction accounted for 69%of the variation of this soil property across the whole native forest coverage in Argentina.Total mean SOC stock reached 2.81 Pg C(2.71–2.84 Pg C with a probability of 90%)for a total area of 460,790 km^(2),where Chaco forests represented 58.4%of total SOC stored,followed by Andean Patagonian forests(16.7%)and Espinal forests(10.0%).SOC stock model was fitted as a function of regional climate,which greatly influenced forest ecosystems,including precipitation(annual mean precipitation and precipitation of warmest quarter)and temperature(day land surface temperature,seasonality,maximum temper-ature of warmest month,month of maximum temperature,night land surface temperature,and monthly minimum temperature).Biodiversity was influenced by the SOC levels and the forest regions.Conclusions In the framework of the Kyoto Protocol and REDD+,information derived in the present work from the estimate of SOC in native forests can be incorporated into the annual National Inventory Report of Argentina to assist forest management proposals.It also gives insight into how native forests can be more resilient to reduce the impact of biodiversity loss.
基金funded by the grant PIP 2021–2023 N°0871“Resilience of managed Nothofagus pumilioforests against harvesting,climate change and extreme events in Tierra del Fuego”of CONICET(Argentina)
文摘Background Forest ecosystems undergo significant transformations due to harvesting and climate fluctuations,emphasizing the critical role of seeding in natural regeneration and long-term structural preservation.Climate change further amplifies these dynamics,affecting phenology across species and regions.In Tierra del Fuego(Argentina),Nothofagus pumilio(lenga)forests represent the most important timber resource,and it is managed through different silvicultural strategies.This species demonstrates notable post-disturbance regeneration,yet seed fall exhibits signifi-cant variability,leading to variations in seed quality(e.g.,viability).This study aims to assess fluctuations in N.pumilio seed quality,determine how it varies concerning forest management strategies,annual productivity,and the co-occurrence of climatic phenomena including El Ni?o-Southern Oscillation(ENSO)and the Southern Annular Mode(SAM).Results Viable seeds represented 18.4%of the total,notably higher in unharvested than in managed areas.Con-versely,empty seeds were more prevalent in harvested areas(>75%).Seed quality exhibited significant differences across silvicultural treatments,except for insect-predated seeds,which had similar proportions across all areas,though dispersed retention showed higher predation.When considering years with varying production levels,high-production years favoured full and viable seeds,particularly in unharvested forests and aggregated retention,while low-production years saw reduced viability across all treatments.Quadratic models revealed that viability increased with seed production,where unharvested forests achieved the highest values.Climate variability influenced seed proportions,where ENSO+/SAM+promoting more full and viable seeds,while ENSO–/SAM+favoured non-predated seeds,especially in unharvested stands.Conclusions Seed quality varies among treatments and years with different levels of seeding.Variations in seed qual-ity,linked to climatic events,influence seed viability.Seed quality plays a critical role in forest regeneration,ensuring a seedling bank for harvested stands to face climate variability.These findings are relevant for forest management and ecosystem services,considering the increasing climate variability and extreme events.Understanding these influ-ences is crucial for Nothofagus pumilio forests'sustainability and global forest adaptation strategies.
文摘Background:Biodiversity supports multiple ecosystem services,whereas species loss endangers the provision of many services and affects ecosystem resilience and resistance capacity.The increase of remote sensing techniques allows to estimate biodiversity and ecosystem services supply at the landscape level in areas with low available data(e.g.Southern Patagonia).This paper evaluates the potential biodiversity and how it links with ecosystem services,based on vascular plant species across eight ecological areas.We also evaluated the habitat plant requirements and their relation with natural gradients.A total of 977 plots were used to develop habitat suitability maps based on an environmental niche factor analysis of 15 more important indicator species for each ecological area(n=53 species)using 40 explanatory variables.Finally,these maps were combined into a single potential biodiversity map,which was linked with environmental variables and ecosystem services supply.For comparisons,data were extracted and compared through analyses of variance.Results:The plant habitat requirements varied greatly among the different ecological areas,and it was possible to define groups according to its specialization and marginality indexes.The potential biodiversity map allowed us to detect coldspots in the western mountains and hotspots in southern and eastern areas.Higher biodiversity was associated to higher temperatures and normalized difference vegetation index,while lower biodiversity was related to elevation and rainfall.Potential biodiversity was closely associated with supporting and provisioning ecosystem services in shrublands and grasslands in the humid steppe,while the lowest values were related to cultural ecosystem services in Nothofagus forests.Conclusions:The present study showed that plant species present remarkable differences in spatial distributions and ecological requirements,being a useful proxy for potential biodiversity modelling.Potential biodiversity values change across ecological areas allowing to identify hotspots and coldspots,a useful tool for landscape management and conservation strategies.In addition,links with ecosystem services detect potential synergies and trade-offs,where areas with the lowest potential biodiversity are related to cultural ecosystem services(e.g.aesthetic values)and areas with the greatest potential biodiversity showed threats related to productive activities(e.g.livestock).
文摘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.
文摘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.
基金Proyecto de apoyo para la Preparación de REDD+en el marco del Fondo Cooperativo de Preparación para el Carbono de los Bosques(FCPF TF019086)Ministerio de Ambiente y Desarrollo Sostenible de la Nación Argentina(2021-2022)Proyectos de Desarrollo Tecnológico y Social(PDTS-0398)MINCyT(Argentina)(2020-2023)+1 种基金Proyectos de Investigación Plurianual(PIP 2021-2023 GI)CONICET(Argentina)(2022-2025)Proyectos Interinstitucionales en Temas Estratégicos(PITES-03)MINCyT(Argentina)(2022-2024).
文摘Background It is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above-and below-ground carbon balance in forest ecosystems.In this context,forest carbon management has gained more attention among managers and policy-makers during recent years.The aim of this study was to determine carbon pool dynamics in different forest ecosystem components after variable retention harvesting(VRH)to characterize the ecological stability and quantify the recovery rate through the years-after-harvesting(YAH).Methods Carbon pool compartmentalization of 14 different components was determined in 60 harvested and primary unmanaged forests during the first 18 YAH in Tierra del Fuego(Argentina).We compared them using uni-and multi-variate methods,relativizing the outputs with primary unmanaged forests.Results We determined the effectiveness to retain carbon components in post-harvested stands under different retention strategies(aggregated vs.dispersed).The balance among carbon pool components changed between managed and unmanaged stands across the YAH,and was directly related to the impact magnitude.Aggregated retention improved the ecological stability of the harvested areas,where the below-ground components were more stable than the above-ground components.The recovery rate was directly related to the post-harvesting natural dynamics of the stands.The studied period was not enough to fully recover the C levels of primary unmanaged for-ests,but VRH showed advantages to increase the C pools in the managed stands.Conclusions Promoting VRH can improve sustainable forestry at the landscape level and in the long term,generating positive synergies with biodiversity and the provision of ecosystem services.This study provides important new insights into forest carbon management,in particular to setting standards in carbon projects and sets the groundwork for analysing the economics of the mentioned harvesting systems.
