• Energy Research

Spatial planning has to deal with trade-offs between various stakeholders’ wishes and needs as part of planning and management of landscapes, natural resources and/or biodiversity. To make ecosystem services (ES) trade-off research more relevant for spatial planning, we propose an analytical framework,which puts stakeholders, their land-use/management choices, their impact on ES and responses at the centre. Based on 24 cases from around the world, we used this framing to analyse the appearance and diversity of real-world ES trade-offs. They cover a wide range of trade-offs related to ecosystem use, including: land-use change, management regimes, technical versus nature-based solutions, natural resource use, and management of species. The ES trade-offs studied featured a complexity that was far greater than what is often described in the ES literature. Influential users and context setters are at the core of the trade-off decision-making, but most of the impact is felt by non-influential users. Provisioning and cultural ES were the most targeted in the studied trade-offs, but regulating ES were the most impacted. Stakeholders’ characteristics, such as influence, impact faced, and concerns can partially explain their position and response in relation to trade-offs. Based on the research findings, we formulate recommendations for spatial planning.

Les forêts de Nothofagus pumilio de la Terre de Feu sont les forêts les plus méridionales du monde, où les conditions climatiques extrêmes représentent un défi pour parvenir à une gestion durable des forêts. La foresterie de rétention a été proposée comme alternative pour augmenter la conservation des espèces dans les peuplements aménagés. Ici, nous avons synthétisé les résultats liés à la mise en œuvre d'une récolte à rétention variable basée sur une combinaison de parcelles d'agrégats et de rétention dispersée au cours des 18 dernières années par rapport à d'autres propositions sylvicoles (par exemple, coupes de bois d'abri) et traitements de contrôle (forêts primaires non gérées). Nous avons résumé les résultats pour (i) les opérations de scierie, (ii) le rendement en bois, (iii) la stabilité de l'étage supérieur, (iv) la structure de la forêt, (v) les cycles microclimatiques et naturels, (vi) la dynamique de régénération naturelle (floraison, ensemencement, recherche de nourriture, recrutement, croissance et mortalité) et (vii) la biodiversité (mammifères, plantes du sous-étage, gui, oiseaux, arthropodes, mousses, lichens et champignons). En général, les parcelles d'agrégats ont maintenu la structure forestière et les variables micro-environnementales, et ont légèrement augmenté les variables de biodiversité et de reproduction forestière par rapport aux forêts primaires non gérées. Au contraire, la rétention dispersée a diminué les variables de la structure forestière et a considérablement augmenté la biodiversité (richesse et abondance) par rapport aux forêts primaires non gérées. Les conditions écologiques sont influencées par la récolte de rétention variable, mais la direction et l'ampleur de l'effet dépendent et diffèrent selon les types de rétention. En outre, les taxons de biodiversité différaient considérablement entre les groupes en fonction des types de rétention. En général, les assemblages d'espèces dans les parcelles agrégées étaient similaires à ceux trouvés dans les forêts primaires non gérées, alors qu'ils étaient significativement modifiés dans la rétention dispersée. Cela s'est produit en raison de (i) l'extinction locale de certaines espèces originales, (ii) l'introduction d'espèces indigènes des environnements environnants, ou (iii) l'invasion d'espèces exotiques. Cette méthode sylvicole a été un outil utile pour conserver la biodiversité et les fonctions des écosystèmes, en s'approchant de l'équilibre entre l'économie, l'écologie et les exigences sociales dans les zones gérées. Los bosques de Nothofagus pumilio en Tierra del Fuego son los bosques más australes del mundo, donde las condiciones climáticas extremas representan un desafío para lograr una gestión forestal sostenible. La silvicultura de retención se propuso como una alternativa para aumentar la protección de especies en los rodales gestionados. Aquí, sintetizamos los resultados relacionados con la implementación de una cosecha de retención variable basada en una combinación de parches agregados y retención dispersa durante los últimos 18 años en comparación con otras propuestas de silvicultura (por ejemplo, cortes de madera de refugio) y tratamientos de control (bosques primarios no gestionados). Resumimos los resultados de (i) operaciones de aserradero, (ii) rendimiento de madera, (iii) estabilidad del sotobosque, (iv) estructura forestal, (v) microclima y ciclos naturales, (vi) dinámica de regeneración natural (floración, siembra, forrajeo, reclutamiento, crecimiento y mortalidad) y (vii) biodiversidad (mamíferos, plantas de sotobosque, muérdagos, aves, artrópodos, musgos, líquenes y hongos). En general, los parches agregados mantuvieron la estructura forestal y las variables microambientales, y aumentaron ligeramente la biodiversidad y las variables de reproducción forestal en comparación con los bosques primarios no gestionados. Por el contrario, la retención dispersa disminuyó las variables de la estructura forestal y aumentó en gran medida la biodiversidad (riqueza y abundancia) en comparación con los bosques primarios no gestionados. Las condiciones ecológicas están influenciadas por la recolección de retención variable, pero la dirección y la magnitud del efecto dependen y difieren según los tipos de retención. Además de esto, los taxones de biodiversidad diferían mucho entre los grupos dependiendo de los tipos de retención. En general, los conjuntos de especies en parches agregados fueron similares a los encontrados en bosques primarios no gestionados, mientras que se modificaron significativamente en la retención dispersa. Esto ocurrió debido a (i) la extinción local de algunas especies originales, (ii) la introducción de especies nativas de los ambientes circundantes, o (iii) la invasión de especies exóticas. Este método silvícola ha sido una herramienta útil para conservar la biodiversidad y las funciones de los ecosistemas, acercándose al equilibrio entre la economía, la ecología y los requisitos sociales en las áreas administradas. 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. غابات Nothofagus pumilio في Tierra del Fuego هي الغابات الواقعة في أقصى الجنوب في العالم، حيث تمثل الظروف المناخية القاسية تحديًا لتحقيق الإدارة المستدامة للغابات. تم اقتراح الاحتفاظ بالغابات كبديل لزيادة الحفاظ على الأنواع في المدرجات المدارة. هنا، قمنا بتجميع النتائج المتعلقة بتنفيذ حصاد الاحتفاظ المتغير بناءً على مزيج من الرقع المجمعة والاحتفاظ المتناثر خلال السنوات الـ 18 الماضية مقارنة بمقترحات زراعة الغابات الأخرى (على سبيل المثال، قطع خشب المأوى) ومعالجات التحكم (الغابات الأولية غير المدارة). قمنا بتلخيص نتائج (1) عمليات المنشرة، و (2) غلة الأخشاب، و (3) الاستقرار المفرط في القصة، و (4) بنية الغابات، و (5) المناخ المحلي والدورات الطبيعية، و (6) ديناميكيات التجديد الطبيعي (الإزهار، والبذر، والبحث عن الطعام، والتجنيد، والنمو، والوفيات)، و (7) التنوع البيولوجي (الثدييات، والنباتات تحت القصة، والدبق، والطيور، والمفصليات، والطحالب، والأشنات، والفطريات). بشكل عام، حافظت الرقع المجمعة على بنية الغابات والمتغيرات البيئية الدقيقة، وزادت بشكل طفيف من التنوع البيولوجي ومتغيرات تكاثر الغابات مقارنة بالغابات الأولية غير المدارة. على العكس من ذلك، قلل الاحتفاظ المتشتت من متغيرات بنية الغابات وزاد بشكل كبير من التنوع البيولوجي (الثراء والوفرة) عند مقارنته بالغابات الأولية غير المدارة. تتأثر الظروف البيئية بحصاد الاحتفاظ المتغير، لكن اتجاه وحجم التأثير يعتمدان ويختلفان وفقًا لأنواع الاحتفاظ. إلى جانب ذلك، اختلفت أصناف التنوع البيولوجي اختلافًا كبيرًا بين المجموعات اعتمادًا على أنواع الاحتفاظ. بشكل عام، كانت تجمعات الأنواع في بقع الركام مماثلة لتلك الموجودة في الغابات الأولية غير المدارة، في حين تم تعديلها بشكل كبير في الاحتفاظ المشتت. حدث هذا بسبب (1) الانقراض المحلي لبعض الأنواع الأصلية، (2) إدخال الأنواع المحلية من البيئات المحيطة، أو (3) غزو الأنواع الغريبة. كانت طريقة زراعة الغابات هذه أداة مفيدة للحفاظ على التنوع البيولوجي ووظائف النظام الإيكولوجي، وتقترب من التوازن بين الاقتصاد والبيئة والمتطلبات الاجتماعية في المناطق المدارة.

Abstract 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.

AbstractChanges in forest openings affect light quality and quantity, and the magnitude of rainfall that reaches the soil surface. Osmorhiza depauperata, a geophyte, acclimates to changes imposed because of forest openings. We studied which changes in biomass allocation allow acclimation of O. depauperata to the various environments that this species inhabits, and where it develops better. Three light intensities (I4 = 4 %, I26 = 26 %, I64 = 64 % of ambient sunlight) and two moisture levels (M40 = 40–60 %, M80 = 80–100 % field capacity) were evaluated on O. depauperata under greenhouse conditions. Plant biomasses per pot were 0.81, 0.56 and 0.48 g at I26, I4 and I64 light intensities, respectively, after one growing season. The biomass allocation to aboveground tissues and leaf area decreased as light intensity increased. Soil moisture modified only belowground biomass and weight of fine roots. The interaction between soil moisture content and light intensity was consistent. This was because of a significant reduction in total plant biomass under high both soil moisture content and high light intensity. Osmorhiza depauperata growth was favored most at medium light intensities. Changes in biomass allocation among various organs allow this species to inhabit forest habitats with different light intensities.

North American beavers (Castor canadensis) are responsible for the major changes in the Tierra del Fuego Archipelago, altering riparian forests for the long-term. Passive restoration of the areas affected was ineffective in the medium-term (up to 20 years), being necessary active strategies. Plantations in abandoned ponds were made with Nothofagus pumilio and N. antarctica tree species across Tierra del Fuego island (Argentina). In the first experiment, we analysed the influence of biotic and abiotic factors in three micro-habitats in the impacted areas: front and tail of ponds, and cut not-flooded forest areas. Five-years-old N. pumilio seedlings had 39% survival in front, 21% in tails, and 46% in cut areas at year-3 of the restoration experiments, being negatively influenced by plant cover and soil moisture. Lower growth was recorded during year-1 (0.7–0.9 cm yr−1), but increased on time (1.9 cm yr−1 front, 1.6 cm yr−1 tail, 4.3 cm yr−1 cut areas). A second experiment explores the alternative to substitute the tree species to face the harder conditions of the impact and climate change. For this, we conducted a new plantation at four locations across the main bioclimatic zones, where 10–40 cm N. antarctica plants attained 17% survival in meadows (front and tail) and 30% in cut areas, being higher with larger than smaller plants (25% vs. 18%), and where they are mainly influenced by rainfall (4% in sites <400 mm yr−1 and 41% in >400 mm yr−1). The main damage was detected in the above-ground biomass due to dryness, but root survival allowed the emergence of new shoots in the following growing season. It is necessary to monitor different Nothofagus species across natural environments in the landscape to determine the feasibility and effectiveness of different strategies in restoration plans, considering the selection of climate-resilient tree species.

Soil total nitrogen (N) stock in rangelands, shrublands, and forests support key ecological functions such as the capacity of the land to sustain plant and animal productivity and ecosystem services. The objective of this study was to model soil total N stocks and soil C/N ratio from 0–30 cm depth across the region using freely accessible information on topography, climate, and vegetation with a view to establishing a baseline against which sustainable land management practices can be evaluated in Southern Patagonia. We used stepwise multiple regression to determine which independent variables best explained soil total N variation across the landscape in Southern Patagonia. We then used multiple regression models to upscale and produce maps of soil total N and C/N across the Santa Cruz province. Soil total N stock to 30 cm ranged from 0.13 to 2.21 kg N m−2, and soil C/N ratios ranged from 4.5 to 26.8. The model for variation of soil total N stock explained 88% of the variance on the data and the most powerful predictor variables were: isothermality, elevation, and vegetation cover (normalized difference vegetation index (NDVI)). Soil total N and soil C/N ratios were allocated to three categories (low, medium, high) and these three levels were used to map the variation of soil total N and soil C/N ratios across Southern Patagonia. The results demonstrate that soil total N decreases as desertification increases, probably due to erosional processes, and that soil C/N is lower at low temperatures and increased with increasing precipitation. Soil total N and soil C/N ratios are critical variables that determine system capacity for productivity, especially the provisioning ecosystem services, and can serve as baselines against which efforts to adopt more sustainable land management practices in Patagonia can be assessed.