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Knowledge acquisition on the response of tree species to drought in the Mediterranean hotspot is an important step to guide adaptation strategies to climate change impacts, e.g., assisted migration.We assessed the resilience components - i.e., resistance, recovery, and resilience - to droughtin 2003 in five provenances of maritime pine planted in four common gardens in Sardinia, and analysed the possible influence of climate variables on these indices. The provenances showed differences in growth rate but not in the components of resilience. Among the provenances, Corsicawas the most productive, while Tuscany was the least. One of the two provenances from Sardinia (Limbara) showed good performance in terms of tree growth in the comparatively drier site. The resilience components were influenced by prevailing environmental conditions at the common gardensites. In the relatively drier sites, trees showed the lowest resistance but the highest recovery values. However, two sites - which had the lowest stand density - showed the opposite trend during the drought year, probably due to moderate thinning. Predictive models showed different probability inthe response of resilience components to climate variables. Resistance and resilience had a similar pattern, both being positively related to temperature, while recovery showed an opposite trend. The models’ results indicate a noticeable adaptation of maritime pine to the drought conditions of Sardinia, though the age factor should be considered as well. Despite only minor differences among provenances being found, environmental conditions and management practices at the common gardens were important in determining tree growth patterns. This study suggests that the provenance of Corsica may provide appropriate material for forest plantations in Mediterranean conditions with mitigation purposes.

The rate of global climate change is projected to outpace the ability of many natural populations and species to adapt. Assisted migration (AM), which is defined as the managed movement of climate‐adapted individuals within or outside the species ranges, is a conservation option to improve species' adaptive capacity and facilitate persistence. Although conservation biologists have long been using genetic tools to increase or maintain diversity of natural populations, genomic techniques could add extra benefit in AM that include selectively neutral and adaptive regions of the genome. In this review, we first propose a framework along with detailed procedures to aid collaboration among scientists, agencies, and local and regional managers during the decision‐making process of genomics‐guided AM. We then summarize the genomic approaches for applying AM, followed by a literature search of existing incorporation of genomics in AM across taxa. Our literature search initially identified 729 publications, but after filtering returned only 50 empirical studies that were either directly applied or considered genomics in AM related to climate change across taxa of plants, terrestrial animals, and aquatic animals; 42 studies were in plants. This demonstrated limited application of genomic methods in AM in organisms other than plants, so we provide further case studies as two examples to demonstrate the negative impact of climate change on non‐model species and how genomics could be applied in AM. With the rapidly developing sequencing technology and accumulating genomic data, we expect to see more successful applications of genomics in AM, and more broadly, in the conservation of biodiversity.

A novel method was tested for improving tree breeding strategies that integrate quantitative and population genetics based on range-wide reciprocal transplant experiments. Five reciprocal common garden tests of Populus tremuloides were investigated including 6450 trees across western Canada focusing on adaptation traits and growth. Both genetic parameters and home-site transplant models were evaluated. We found a genetic trade-off between growth and early spring leaf flush and late fall senescence. Coefficients of phenotypic variation (CVp) of cell lysis (CL), a measure of freezing injury, shrank from 0.28 to 0.10 during acclimation in the fall, and the CVp slope versus the freezing temperature was significantly different from zero (R2 = 0.33, p = .02). There was more between-population genetic variation in fall phenology than in spring leaf phenology. We suggest that P. tremuloides demonstrated a discrepancy between the ecological optimum and the physiological optimum minimum winter temperature. The sub-optimal growing condition of P. tremuloides is potentially caused by the warmer ecological optimum than the physiological optimum. Assisted migration and breeding of fast growers to reforest cooler plantation sites can improve productivity. Transferring the study populations to less than 4°C of extreme minimum temperature appears safe for reforestation aligning with the historical recolonization direction of the species. This is equivalent to a 5–10° latitudinal northward movement. Fall frost hardiness is an effective criterion for family selection in the range tested in this study.

Conservation actions to safeguard climate change vulnerable species may not be utilized due to a variety of perceived barriers. Assisted colonization, the intentional movement and release of an organism outside its historical range, is one tool available for species predicted to lose habitat under future climate change scenarios, particularly for single island or single mountain range endemic species. Despite the existence of policies that allow for this action, to date, assisted colonization has rarely been utilized for species of conservation concern in the Hawaiian Islands. Given the potential for climate driven biodiversity loss, the Hawaiian Islands are a prime location for the consideration of adaptation strategies. We used first-person interviews with conservation decision makers, managers, and scientists who work with endangered species in the Hawaiian Islands to identify perceived barriers to the use of assisted colonization. We found that assisted colonization was often not considered or utilized due to a lack of expertize with translocations; ecological risk and uncertainty, economic constraints, concerns regarding policies and permitting, concerns with public perception, and institutional resistance. Therefore, conservation planners may benefit from decision tools that integrate risk and uncertainty into decision models, and compare potential outcomes among conservation actions under consideration, including assisted colonization. Within a decision framework that addresses concerns, all conservation actions for climate sensitive species, including assisted colonization, may be considered in a timely manner.

Many species are shifting their ranges to keep pace with climate change, but habitat fragmentation and limited dispersal could impede these range shifts. In the case of climate-vulnerable foundation species such as tropical reef corals and temperate forest trees, such limitations might put entire communities at risk of extinction. Restoring connectivity through corridors, stepping-stones or enhanced quality of existing patches could prevent the extinction of several species, but dispersal-limited species might not benefit if other species block their dispersal. Alternatively, managers might relocate vulnerable species between habitats through assisted migration, but this is generally a species-by-species approach. To evaluate the relative efficacy of these strategies, we simulated the climate-tracking of species in randomized competitive metacommunities with alternative management interventions. We found that corridors and assisted migration were the most effective strategies at reducing extinction. Assisted migration was especially effective at reducing the extinction likelihood for short-dispersing species, but it often required moving several species repeatedly. Assisted migration was more effective at reducing extinction in environments with higher stochasticity, and corridors were more effective at reducing extinction in environments with lower stochasticity. We discuss the application of these approaches to an array of systems ranging from tropical corals to temperate forests. This article is part of the theme issue ‘Ecological complexity and the biosphere: the next 30 years’.

Resource managers face mounting challenges when it comes to the implementation of climate change adaptation strategies. Novel adaptation strategies, such as managed relocation, frequently entail embracing substantial risk of unintended harm to the focal ecosystems, in an effort to alleviate serious threats to biological diversity (e.g. extinction). Assessing ecological risks associated with different adaptation strategies is consistently called for, but the process for doing so is often undefined. Here, we describe a collaboration amongst university researchers, agency scientists and resource managers to create a set of ecological risk assessment protocols for managed relocation decision support. These protocols are designed to foster a rigorous assessment of ecological risk, while simultaneously being flexible and easy to use. We describe a collaborative process through which we developed a structure for assessing risk that includes a suite of 17 risk categories aggregated into six overarching groups, which is placed within a broader decision context for managed relocation (e.g. evaluating feasibility, social acceptability). Our risk scoring includes both scaled estimates of risk and perceived confidence in those estimates. Because of differences in the importance of risk categories, we do not recommend a quantitative summary across risk areas, but suggest decision makers make decisions based on three criteria: overall confidence that a proposed action can be confidently evaluated; low overall level or risk across categories; and no single risk category that is highly likely to result in severe adverse outcomes.

The pH/Tduality of acidic pH and temperature (T) action for the growth of grass shoots was examined in order to derive the phenomenological equation of wall properties for living plants. By considering non-meristematic growth as a dynamic series of state transitions (STs) in the extending primary wall, the critical exponents were identified, which exhibit a singular behaviour at a critical temperature, critical pH and critical chemical potential (μ) in the form of four power laws:$$f_{\pi } \left( \tau \right) \propto \left| \tau \right|^{\beta - 1}$$fπτ∝τβ-1,$$f_{\tau } (\pi ) \propto \left| \pi \right|^{1 - \alpha }$$fτ(π)∝π1-α,$$g_{\mu } (\tau ) \propto \left| \tau \right|^{ - 2 - \alpha + 2\beta }$$gμ(τ)∝τ-2-α+2βand$$g_{\tau } (\mu ) \propto \left| \mu \right|^{2 - \alpha }$$gτ(μ)∝μ2-α. The indicesαandβare constants, whileπandτrepresent a reduced pH and reduced temperature, respectively. The convexity relationα + β ≥ 2 for practical pH-based analysis andβ ≡ 2 “mean-field” value in microscopic (μ) representation were derived. In this scenario, the magnitude that is decisive is the chemical potential of the H+ions, which force subsequent STs and growth. Furthermore, observation that the growth rate is generally proportional to the product of the Euler beta functions ofTand pH, allowed to determine the hidden content of the Lockhart constantФ. It turned out that the pH-dependent time evolution equation explains either the monotonic growth or periodic extension that is usually observed—like the one detected in pollen tubes—in a unified account.

With climate change impacting trees worldwide, enhancing adaptation capacity has become an important goal of provenance translocation strategies for forestry, ecological renovation, and biodiversity conservation. Given that not every species can be studied in detail, it is important to understand the extent to which climate adaptation patterns can be generalised across species, in terms of the selective agents and traits involved. We here compare patterns of genetic-based population (co)variation in leaf economic and hydraulic traits, climate–trait associations, and genomic differentiation of two widespread tree species (Eucalyptus pauciflora and E. ovata). We studied 2-yearold trees growing in a common-garden trial established with progeny from populations of both species, pair-sampled from 22 localities across their overlapping native distribution in Tasmania, Australia. Despite originating from the same climatic gradients, the species differed in their levels of population variance and trait covariance, patterns of population variation within each species were uncorrelated, and the species had different climate–trait associations. Further, the pattern of genomic differentiation among populations was uncorrelated between species, and population differentiation in leaf traits was mostly uncorrelated with genomic differentiation. We discuss hypotheses to explain this decoupling of patterns and propose that the choice of seed provenances for climatebased plantings needs to account for multiple dimensions of climate change unless species-specific information is available info:eu-repo/semantics/publishedVersion

Understanding local adaptation of tree populations to climate allows the development of assisted migration guidelines as a tool for forest managers to address climate change. Here, we study the relationship among climate, a wide range of physiological traits, and field performance of selected white spruce provenances originating from throughout the species range. Tree height, survival, cold hardiness, hydraulic, and wood anatomical traits were measured in a 32‐year‐old common garden trial, located in the center of the species range. Provenance performance included all combinations of high versus low survival and growth, with the most prevalent population differentiation for adaptive traits observed in cold hardiness. Cold hardiness showed a strong association with survival and was associated with cold winter temperatures at the site of seed origin. Tree height was mostly explained by the length of the growing season at the origin of the seed source. Although population differentiation was generally weak in wood anatomical and hydraulic traits, within‐population variation was substantial in some traits, and a boundary analysis revealed that efficient water transport was associated with vulnerable xylem and low wood density, indicating that an optimal combination of high water transport efficiency and high cavitation resistance is not possible. Our results suggest that assisted migration prescriptions may be advantageous under warming climate, but pronounced trade‐offs between survival and cold hardiness require a careful consideration of the distances of these transfers.

Background and Aims Knowledge of thermal acclimation of physiological processes of boreal tree species is necessary to determine their ability to adapt to predicted global warming and reduce the uncertainty around the anticipated feedbacks of forest ecosystems and global carbon cycle to climate change. The objective of this work was to examine the extent of thermal acclimation of net photosynthesis (An) and dark respiration (Rd) of two distant white spruce (Picea glauca) seed sources (from south and north of the commerial forest zone in Québec) in response to latitudinal and seasonal variations in growing conditions. Methods The temperature responses of An, its biochemical and biophysical limitations, and Rd were measured in 1-year-old needles of seedlings from the seed sources growing in eight forest plantations along a regional thermal gradient of 5.5 °C in Québec, Canada. Key Results The average optimum temperature (Topt) for An was 19 ± 1.2 °C and was similar among seed sources and plantation sites along the thermal gradient. Net photosynthesis at Topt (Aopt) varied significantly among plantation sites and was quadratically related to the mean July temperature (MJT) of plantation sites. Topt for mesophyll conductance, maximum electron transport rate and maximum rate of carboxylation were 28, 22 and 30 °C, respectively. Basal respiration rate (Rd at 10 °C) was linearly and negatively associated with MJT. Q10 of Rd (the rate of change in Rd with a 10 °C increase in temperature) did not show any significant relationship with MJT and averaged 1.5 ± 0.1. The two seed sources were similar in their thermal responses to latitudinal and seasonal variations in growing conditions. Conclusions The results showed moderate thermal acclimation of respiration and no evidence for thermal acclimation of photosynthesis or local genetic adaptation for traits related to thermal acclimation. Therefore, growth of local white spruces may decline in future climates.

Climate change challenges important native timber species in Central Europe. The introduction of non-native tree species originating from warmer climates is one option to make Central European forests compatible to global warming. This, however, requires an assessment of the species’ growth requirements, and of its impact on biodiversity in its native ranges. Silver lime (Tilia tomentosa), a moderately drought-tolerant, thermophilous tree species of South-eastern Europe is considered suitable for the future. Along three elevational transects in western Romania, we assessed the impact of changing climate and local site conditions on the abundance of this tree species and contrasted plant species diversity and composition of lime-dominated forests with mesophytic oak and beech forests. Local site conditions and disturbance histories shaped the distribution pattern of silver lime. When dominant, it reduced plant species diversity within stands due to its dense canopy. For shade-tolerant, mesophytic species, though, lime forests provided an additional habitat and extended their range into warmer environments. Thus, silver lime may have the potential as an admixed tree species forming a transitory meso-thermophilous habitat in the future. At the same time, silver lime may be limited under increasing drought frequency.

This datapaper collects individual georeferenced tree height data from Pinus nigra Arn., P. pinaster Aiton, and P. pinea L. planted in common gardens in France, Germany, Morocco, and Spain. The data can be used to assess genetic variation and phenotypic plasticity with further applications in biogeography and forest management. The three datasets are available at (Vizcaino-Palomar et al. 2018a), (Vizcaino-Palomar et al. 2018b), and (Vizcaino-Palomar et al. 2018c), and the associated metadata are available at , and for P. nigra, P. pinaster and P. pinea, respectively.

Research Highlights: Reciprocal altitudinal transplants of Abies religiosa seedlings within the Monarch Butterfly Biosphere Reserve (MBBR) allow prediction of the impacts of climatic change, because they grow in sites with a climate that differs from that of their origin. Background and Objectives: Climatic change is generating a mismatch between the sites currently occupied by forest populations and the climate to which they have adapted. This study determined the effect on the survival and growth of A. religiosa seedlings of transfer to sites that were warmer or colder than that of the origin of their seeds. Materials and Methods: Eleven provenances of A. religiosa, collected along an altitudinal gradient (3000 to 3550 m a.s.l.), were assayed in common gardens in three sites of contrasting altitude: 3400, 3000 and 2600 m a.s.l. The results were evaluated by fitting a response curve with a mixed model. Results: The climate transfer distance for the seasonal balance between the temperature conducive to growth (degree days above 5 &deg, C) and the available precipitation (a ratio expressed as dryness index) dominated the shape of the response function curve. The rainy season (June&ndash, October) dryness index transfer distance was critical for survival, while that of the cold and dry season (November&ndash, February) was critical for aerial biomass, and the annual index was critical for the increase in basal diameter. The effect of climatic transfer distance is much more negative (triggering about 45% mortality) when transfer is toward warmer and dryer sites (at 400 m lower in altitude, +1.9 &deg, C warmer and 16% less precipitation), than when shifting toward colder and wetter sites (400 m higher in altitude, resulting in 95% survival). Conclusions: The projected higher temperatures and lower precipitation due to climatic change will undoubtedly cause severe mortality in young A. religiosa seedlings. A 400 m shift upwards in altitude to compensate for climatic change (assisted migration) appears to be a feasible management action.

Ongoing climate change is leading to significant range shifts in many taxa. Although climate-induced spatiotemporal dynamics have subtle implications for prioritization of translocation release areas, the terminology underlying current guidelines for conservation translocation remains focused on a dichotomy between ‘reintroductions’ within the indigenous range and ‘assisted colonisations’ anywhere else. We here propose a dispersal barrier-based framework for categorizing release areas according to their compatibility with natural ecological processes under climate change. Setting as a criterion that consistently suitable conditions are forecast over the timeframe considered, we define six translocation types corresponding to six translocation release zones: ‘reinforcement’ within the ‘stable current range’; ‘assisted dispersal sensu stricto’ within the ‘expected novel range’; ‘compensatory dispersal’ within the ‘idealized novel range’ (i.e. projected only if simulating absence of anthropogenic dispersal barriers); ‘accelerated dispersal’ within the ‘expected connected envelope’ (i.e. the spatiotemporally connected bioclimatic envelope beyond dispersal range); ‘accelerated compensatory dispersal’ within the ‘idealized connected envelope’ (i.e. unreachable connected envelope only if simulating absence of anthropogenic dispersal barriers); and ‘artificial dispersal’ within the ‘unconnected envelope’ (i.e. separated by natural physical barriers). Analysing projected range change in African antelopes by 2080, translocation across natural dispersal barriers was associated with elevated potential for interspecific competition with allopatric species and hence possible interference with ecosystem function. We argue that where translocation within the indigenous range is not an option, priority ranking of release sites would benefit from explicit consideration of dispersal barriers, favouring projected novel ranges above areas separated by distance and, especially, natural physical obstacles.

Propagating and releasing freshwater mussels (Unionida) into the wild can contribute substantially to conservation and perhaps ecosystem restoration, but poorly conceived projects can waste money and public good will, and harm mussel populations and ecosystems. Moving from vague, emotional reactions about mussel restoration to more rigorous discussions and analyses can help focus efforts to where they do the most good. We suggest that: (i) projects to restore mussels for conservation goals to sites where known environmental problems have been eliminated or mitigated have good prospects for success; (ii) projects to restore mussels for conservation goals to sites where known environmental problems have not been eliminated or mitigated have poor prospects for success; (iii) projects to restore mussels for conservation goals to sites in the common situation in which the status of environmental problems is unknown have unknown prospects for success, but may be valuable as scientific experiments, if project performance is monitored properly; (iv) the value of population augmentation as a conservation tool is uncertain, and needs better theoretical and empirical analysis; (v) assisted migration of mussels as a conservation tool is controversial, and should be discussed thoroughly before we reach crises in which it is rejected or carried out carelessly; (vi) projects to restore ecosystem services face more stringent criteria for success than conservation projects, and some such projects being discussed seem unlikely to succeed. Monitoring data on how restoration projects perform typically are inadequately collected, reported, disseminated, and used to improve practice. This could be improved by setting up a clearinghouse to collect, hold, and disseminate data; providing training to restorationists; and opening conversations between restorationists and data managers and statisticians.

Tree seedling resistance to and recovery from abiotic stressors such as drought and warming are crucial for forest regeneration and persistence. Selection of more resilient provenances and their use in forest management programs might alleviate pressures of climate change on forest ecosystems. Scots pine forests in particular have suffered frequent drought-induced mortality, suggesting high vulnerability to extreme events. Here, we conducted an experiment using potted Scots pine seedlings from ten provenances of its south-western distribution range to investigate provenance-specific impacts of multiple drought events. Seedlings were grown under ambient and elevated temperatures for 1.5 years and were subjected to consecutive droughts during spring and summer. Growth (height, diameter, and needle) and spring phenology were monitored during the whole study period and complemented by biomass assessments (bud, needle, wood, and needle/wood ratio) as well as measurements of chlorophyll fluorescence and of needle stable carbon isotope ratio. Phenology, growth and biomass parameters as well as carbon isotope ratio and their (direct) responses to reoccurring droughts differed between provenances, indicating genotypic adaptation. Seedling growth was plastic during drought with intra- and inter-annual compensatory growth after drought stress release (carryover effects), however, not fully compensating the initial impact. For (smaller) seedlings from southern/drier origins, sometimes greater drought resistance was observed which diminished under warmer conditions in the greenhouse. Warming increased diameter growth and advanced phenological development, which was (partly) delayed by drought in 2013, but advanced in 2014. Earlier phenology was linked to higher growth in 2013, but interestingly later phenology had positive effects on wood and needle biomass when subjected to drought. Lastly, stable carbon isotope ratios indicated a clear drought response of carbon assimilation. Drought-induced reduction of the photosystem II efficiency was only observed under warmer conditions but showed compensation under ambient temperatures. Besides these direct drought impacts, also interactive effects of previous drought events were shown, either reinforcing or sometimes attenuating the actual impact. Thus, depending on amount and timing of events, Scots pine seedlings, particularly from southern origins, might be well adapted and resilient to drought stress and should be considered when discussing assisted migration under changing climatic conditions.

Anthropogenic landscape‐level alterations such as habitat fragmentation and long distance translocation of genetic material are currently altering the genetic connectivity and structure of forest tree populations globally. As the susceptibility of individual trees to dependent organisms is often genetically determined, it is possible that these genetic changes may extend beyond individuals to affect associated communities. To test this, we examined how variation in crossing distance among the progeny of 18 controlled crosses of Norway spruce (Picea abies) populations occurring across central Sweden affected chemical defense, and subsequently, a small community of galling Adelges aphids infecting planted trees at two common garden trails. Although crossing distance did not influence growth, vitality or reproduction in the studied population, it did influence the expression of one candidate defensive chemical compound, apigenin, which was found in higher concentrations within outcrossed trees. We also show that this variation in apigenin induced by crossing distance correlated with susceptibility to one member of the galling community but not the other. Furthermore, the effect of crossing distance on galling communities and the general susceptibility of Norway spruce to infection also varied with environment. Specifically, in the more benign environment, inbred trees suffered greater gall infection than outcrossed trees, which is contrary to general predictions that the effects of inbreeding should be more pronounced in harsher environments. These findings suggest that the effects of variation in crossing distance in forest trees can extend beyond the individual to influence whole communities.

With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea glauca [Moench] Voss) seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1) evaluate the morpho-physiological responses of the different seed sources and (2) determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a significant effect on photosynthesis before bud break. The observed results during the establishment phase under different site conditions indicate that southern seed sources may already benefit from assisted migration to cooler climatic conditions further north. While northern seed sources are likely to benefit from anticipated local global warming, they would not match the growth performance of seedlings from southern sources.

[EN] In the mid-twentieth century, the overseas emigration from Europe was in clear decline, but both Spain and Argentina tried to revitalize this flow that had carried thousands of families to the South American country decades earlier. Owing to economic, political and ideological reasons, both governments allocated an enormous amount of resources to fostering this migratory movement, a goal in which the Intergovernmental Committee for European Migration (ICEM) was also involved. Thanks to this assistance, many Spanish families with no resources were able to emigrate and settle in Argentinean territory. However, not everything turned into benefits for the migrants. The implemented plans also suffered from serious defects that, in many cases, caused more difficulties than they tried to solve. In this paper, we will analyze these problems and the attempts to resolve them., [ES] A mediados del siglo XX, pese a los claros síntomas de declive de la emigración europea hacia ultramar, tanto España como Argentina intentaron revitalizar la corriente que décadas antes había llevado a miles de familias a establecerse en el país sudamericano. Por motivos económicos, políticos e ideológicos, ambos gobiernos dedicaron una ingente cantidad de recursos a fomentar este movimiento migratorio, objetivo en el que también estaba volcado el Comité Intergubernamental para las Migraciones Europeas (CIME), un organismo cuya existencia dependía precisamente del mantenimiento de los flujos transoceánicos. Gracias a esta asistencia, muchas familias españolas sin recursos pudieron emigrar y establecerse en territorio argentino, pero no todo se tradujo en beneficios para los migrantes. Los programas de mano de obra y de reagrupación familiar, a los que estos se acogieron, adolecían de defectos que en muchos casos terminaron causando problemas más graves de los que pretendían solventar. En el presente artículo se analizarán estos problemas y los intentos de solución por parte de sus responsables.

Vulnerability assessments can provide useful information for the establishment of climate change adaptation strategies. We performed spatial vulnerability assessments for multiple plant species that incorporate potential range shifts to areas of future suitable climate. We conducted the assessments at a national level for plant species organized into vulnerable species groups. We then identified a climate meta-corridor for each vulnerable group that could potentially be a pathway for multiple species. We estimated climate suitability for 2297 South Korean terrestrial plant species under current climate conditions and climate projections for 2050 using the Multivariate Adaptive Regression Splines multiresponse species distribution model. We classified the plants into five groups based on their current spatial distribution patterns: centrally located species, wide-range species, coastal mountain species, montane species, and lowland species. Three vulnerability assessment components — exposure, spatial disruption, and dispersal pressure — were used to calculate the spatial vulnerability of each species. Vulnerability values were averaged by group. We identified climate meta-corridors that would link current suitable areas to future climatically suitable areas, and tested the corridors for multi-species accessibility. The vulnerability assessment indicates that coastal mountain, montane, and lowland species groups, comprising 37% of all modelled species, are the most vulnerable to climate change. The climate meta-corridor for each group overlaps at least some portion of 83% or more of its species' current modelled ranges. The current and future climate-suitable areas for the lowland species group have very little spatial overlap, suggesting a high priority should be placed on the corridor identified for these species. We found that the destinations of the climate corridors converge, raising questions about large numbers of species moving to limited areas, and that transboundary corridor modelling is needed on the Korean Peninsula. Policy implications. Each of the three meta-corridors has unique policy implications: assisted migration for the highest elevation species for the montane; significant conservation and restoration work for the lowland; and perhaps no direct intervention but monitoring to evaluate effectiveness of the relatively intact habitats of the coastal mountain meta-corridor. Overall, implementation policies for climate connectivity will be context-dependent, requiring different approaches dependent on local and regional conditions and the species targeted.

Considering climate change, the discussion intensifies whether and to what extent exotic tree species should be taken into account for forest cultivation, especially when indigenous species are no longer able to fulfill essential forest functions. In this study, for the first time growth potential of Cedrus libani was evaluated under climatic conditions in Central Europe (Bayreuth, Germany). The sampled trees exhibited extraordinary growth with tree ring widths averaging 4.9 mm year(-1) during the past 23 years. A continuously available soil water supply enhanced radial stem growth. Thus, growth declined during the dry year of 2003, but recovered to average values the following year. Our results confirm that C. libani is a light-demanding species which is sensitive to competition and which shows a typical age trend. In a second study, we compared cambial growth in Bayreuth with a natural stand in Elmali (Turkey) in 2009. Cambial growing season in Bayreuth was 45 days longer, and radial growth rates in Bayreuth were four times higher than in Elmali. Interestingly, C. libani maintained a slow but continuous radial growth at Elmali even during the dry summer period, confirming its exceptional drought tolerance. Our results indicate a high adaption of C. libani to current and future climate conditions in Central Europe. It tolerates extreme cold in winter and prolonged droughts during summer. Thus, its promising potential for establishing stable and productive forest stands in Central Europe under a changing climate should be confirmed in further studies.

International audience; The conservation and sustainable use of forests in the twenty-first century pose huge challenges for forest management and policy. Society demands that forests provide a wide range of ecosystem services, from timber products, raw materials and renewable energy to sociocultural amenities and habitats for nature conservation. Innovative management and policy approaches need to be developed to meet these often-conflicting demands in a context of environmental change of uncertain magnitude and scale. Genetic diversity is a key component of resilience and adaptability. Overall, forest tree populations are genetically very diverse, conferring them an enormous potential for genetic adaptation via the processes of gene flow and natural selection. Here, we review the main challenges facing our forests in the coming century and focus on how recent progress in genetics can contribute to the development of appropriate practical actions that forest managers and policy makers can adopt to promote forest resilience to climate change. Emerging knowledge will inform and clarify current controversies relating to the choice of appropriate genetic resources for planting, the effect of silvicultural systems and stand tending on adaptive potential and the best ways to harness genetic diversity in breeding and conservation programs. Gaps in our knowledge remain, and we identify where additional information is needed (e.g., the adaptive value of peripheral populations or the genetic determinism of key adaptive traits) and the types of studies that are required to provide this key understanding.

Climate change may endanger not only yield and fulfilling the social functions of European forests, but even the survival of several tree species. The study emphasises the complexity of climatic factors and physiological mechanisms, which may potentially endanger the persistence of tree populations and which cannot be reduced to problems of drought and temperature increase. A substantial inter-population variation in traits associated with the response to climatic stress, observed in provenance experiments, is a prerequisite for the choice of proper forest reproductive material (FRM) in reforestation as a strategy of climate-change mitigation. Assisted migration, i.e., transfer of FRM from source regions, currently characterised by such climate characteristics, which are expected in the target regions in the future, requires knowledge of key stress factors (depending on the climate scenario), physiological processes associated with the adaptation to this stress, identification of genes and eventually epigenetic mechanisms, controlling adaptation processes, and finally mapping of genetic and/or epigenetic variation in key genes. For most tree species, such information is not yet available. Therefore, assisted migration under such information uncertainty needs to be complemented by in situ gene conservation measures to preserve the possibility of reversing the effects of eventual erroneous decisions on FRM transfer.

Hawaiian forest birds are imperiled, with fewer than half the original >40 species remaining extant. Recent studies document ongoing rapid population decline and project complete climate‐based range losses for the critically endangered Kaua'i endemics ‘akeke’e (Loxops caeruleirostris) and ‘akikiki (Oreomystis bairdi) by end‐of‐century due to projected warming. Climate change facilitates the upward expansion of avian malaria into native high elevation forests where disease was historically absent. While intensified conservation efforts attempt to safeguard these species and their habitats, the magnitude of potential loss and the urgency of this situation require all conservation options to be seriously considered. One option for Kaua’i endemics is translocation to islands with higher elevation habitats. We explored the feasibility of interisland translocation by projecting baseline and future climate‐based ranges of ‘akeke’e and ‘akikiki across the Hawaiian archipelago. For islands where compatible climates for these species were projected to endure through end‐of‐century, an additional climatic niche overlap analysis compares the spatial overlap between Kaua’i endemics and current native species on prospective destination islands. Suitable climate‐based ranges exist on Maui and Hawai'i for these Kaua'i endemics that offer climatically distinct areas compared to niche distributions of destination island endemics. While we recognize that any decision to translocate birds will include assessing numerous additional social, political, and biological factors, our focus on locations of enduring and ecologically compatible climate‐based ranges represents the first step to evaluate this potential conservation option. Our approach considering baseline and future distributions of species with climatic niche overlap metrics to identify undesirable range overlap provides a method that can be utilized for other climate‐vulnerable species with disjointed compatible environments beyond their native range.

Species distribution models (SDMs), especially those basing on climatic parameters, have frequently been used to project future species ranges and to develop conservation strategies. As suggested by several authors, we considered both different dispersal abilities and different evolutionarily significant units (ESUs, as determined in an earlier genetic survey). For our study species, the flightless ground beetle Carabus irregularis, SDMs for two ESUs from the western and the Carpathian area of the distribution range showed immense, and deviating future range contractions reflecting divergent ecological requirements. As minimal dispersal SDMs resulted in a stronger decline of future ranges than the maximal dispersal models, low dispersal ability tended to strengthen the already high vulnerability of the cold-adapted mountain species to global warming. Areas shown in our maximal dispersal models as offering climatically suitable habitats for C. irregularis in the future should be considered as potential areas of action in future conservation planning (e.g. assisted migration or assisted colonisation). Thus, both dispersal scenarios and different (if applicable) ESUs should be considered when developing SDMs as useful tools for species conservation strategies adapted to species' performance and differentiation patterns. Species distribution models (SDMs), especially those basing on climatic parameters, have frequently been used to project future species ranges and to develop conservation strategies. As suggested by several authors, we considered both different dispersal abilities and different evolutionarily significant units (ESUs, as determined in an earlier genetic survey). For our study species, the flightless ground beetle Carabus irregularis, SDMs for two ESUs from the western and the Carpathian area of the distribution range showed immense, and deviating future range contractions reflecting divergent ecological requirements. As minimal dispersal SDMs resulted in a stronger decline of future ranges than the maximal dispersal models, low dispersal ability tended to strengthen the already high vulnerability of the cold-adapted mountain species to global warming. Areas shown in our maximal dispersal models as offering climatically suitable habitats for C. irregularis in the future should be considered as potential areas of action in future conservation planning (e.g. assisted migration or assisted colonisation). Thus, both dispersal scenarios and different (if applicable) ESUs should be considered when developing SDMs as useful tools for species conservation strategies adapted to species' performance and differentiation patterns.

Recent population declines to the high elevation western North America foundation species whitebark pine, have been driven by the synergistic effects of the invasive blister rust pathogen, mountain pine beetle (MPB), fire exclusion, and climate change. This has led to consideration for listing whitebark pine (WBP) as a threatened or endangered species under the Endangered Species Act, which has intensified interest in developing management strategies for maintaining and restoring the species. An important, but poorly studied, aspect of WBP restoration is the spatial variation in adaptive genetic variation and the potential of blister rust resistant strains to maintain viable populations in the future. Here, we present a simulation modeling framework to improve understanding of the long-term genetic consequences of the blister rust pathogen, the evolution of rust resistance, and scenarios of planting rust resistant genotypes of whitebark pine. We combine climate niche modeling and eco-evolutionary landscape genetics modeling to evaluate the effects of different scenarios of planting rust-resistant genotypes and impacts of wind field direction on patterns of gene flow. Planting scenarios showed different levels for local extirpation of WBP and increased population-wide blister rust resistance, suggesting that the spatial arrangement and choice of planting locations can greatly affect survival rates of whitebark pine. This study presents a preliminary, but potentially important, framework for facilitating the conservation of whitebark pine.

Because of changes in climatic conditions, tree seeds originating from breeding programs may no longer be suited to sites where they are currently sent. As a consequence, new seed zones may have to be delineated. Assisted migration consists of transferring seed sources that match the future climatic conditions to which they are currently adapted. It represents a strategy that could be used to mitigate the potential negative consequences of climate change on forest productivity. Decisions with regard to the choice of the most appropriate seed sources have to rely on appropriate knowledge of morpho-physiological responses of trees. To meet this goal, white spruce (Picea glauca [Moench] Voss) seedlings from eight seed orchards were evaluated during two years in a forest nursery, and at the end of the first growing season on three plantation sites located in different bioclimatic domains in Quebec. The morpho-physiological responses obtained at the end of the second growing season (2+0) in the nursery made it possible to cluster the orchards into three distinct groups. Modelling growth curves of these different groups showed that the height growth of seedlings from the second-generation and southern first-generation seed orchards was significantly higher than that of those from other orchards, by at least 6%. A multiple regression model with three climatic variables (average growing season temperature, average July temperature, length of the growing season) showed that the final height of seedlings (2+0) from the first-generation seed orchards was significantly related to the local climatic conditions at the orchard sites of origin where parental trees from surrounding natural populations were sampled to provide grafts for orchard establishment. Seedling height growth was significantly affected by both seed source origins and planting sites, but the relative ranking of the different seed sources was maintained regardless of reforestation site. This knowledge could be used, in conjunction with transfer models, to refine operational seed transfer rules and select the most suitable sites in an assisted migration strategy.

Assisted population migration (APM) is the intentional movement of populations within a species range to sites where future environmental conditions are projected to be more conducive to growth. APM has been proposed as a proactive adaptation strategy to maintain forest productivity and to reduce the vulnerability of forest ecosystems to projected climate change. The validity of such a strategy will depend on the adaptation capacity of populations, which can partially be evaluated by the ecophysiological response of different genetic sources along a climatic gradient. This adaptation capacity results from the compromise between (i) the degree of genetic adaptation of seed sources to their environment of origin and (ii) the phenotypic plasticity of functional trait which can make it possible for transferred seed sources to positively respond to new growing conditions. We examined phenotypic variation in morphophysiological traits of six seed sources of white spruce (Picea glauca [Moench] Voss) along a regional climatic gradient in Quebec, Canada. Seedlings from the seed sources were planted at three forest sites representing a mean annual temperature gradient of 2.2 °C. During the second growing season, we measured, height growth (H2014) and traits related to resources use efficiency and photosynthetic rate (Amax). All functional traits showed an adaptive response to the climatic gradient. Traits such as H2014, Amax, stomatal conductance (gs), the ratio of mesophyll to stomatal conductance, water use efficiency and photosynthetic nitrogen-use efficiency showed significant variation related to both physiological plasticity related to test site, and seed source variation related to local genetic adaptation. However, the amplitude of seed source variation was much less than that related to plantation sites in the area investigated. The six seed sources presented a similar level of physiological plasticity. H2014, Amax and gs, but not carboxylation capacity (Vcmax), were correlated and decreased with a reduction of the average temperature of the growing season at seed origin. The clinal variation in H2014 and Amax appeared to be driven by CO2 conductance. The presence of locally adapted functional traits suggests that the use of assisted population migration may have advantages for optimizing seed source productivity in future local climates

We investigated adaptation to climate in populations of two widespread tree species across a range of contrasting environments in western Canada. In a series of common garden experiments, bud phenology, cold hardiness, and seedling growth traits were assessed for 254 populations in the interior spruce complex (Picea glauca, P. engelmannii, and their hybrids) and for 281 populations of lodgepole pine (Pinus contorta). Complex multitrait adaptations to different ecological regions such as boreal, montane, coastal, and arid environments accounted for 15–20% of the total variance. This population differentiation could be directly linked to climate variables through multivariate regression tree analysis. Our results suggest that adaptation to climate does not always correspond linearly to temperature gradients. For example, opposite trait values (e.g., early versus late budbreak) may be found in response to apparently similar cold environments (e.g., boreal and montane). Climate change adaptation strategies may therefore not always be possible through a simple shift of seed sources along environmental gradients. For the two species in this study, we identified a relatively small number of uniquely adapted populations (11 for interior spruce and nine for lodgepole pine) that may be used to manage adaptive variation under current and expected future climates.

Intraspecific assisted migration (ISAM) through seed transfer during artificial forest regeneration has been suggested as an adaptation strategy to enhance forest resilience and productivity under future climate. In this study, we assessed the risks and benefits of ISAM in white spruce based on long-term and multilocation, rangewide provenance test data. Our results indicate that the adaptive capacity and growth potential of white spruce varied considerably among 245 range-wide provenances sampled across North America; however, the results revealed that local populations could be outperformed by nonlocal ones. Provenances originating from south-central Ontario and southwestern Quebec, Canada, close to the southern edge of the species' natural distribution, demonstrated superior growth in more northerly environments compared with local populations and performed much better than populations from western Canada and Alaska, United States. During the 19–28 years between planting and measurement, the southern provenances have not been more susceptible to freezing damage compared with local populations, indicating they have the potential to be used now for the reforestation of more northerly planting sites; based on changing temperature, these seed sources potentially could maintain or increase white spruce productivity at or above historical levels at northern sites. A universal response function (URF), which uses climatic variables to predict provenance performance across field trials, indicated a relatively weak relationship between provenance performance and the climate at provenance origin. Consequently, the URF from this study did not provide information useful to ISAM. The ecological and economic importance of conserving white spruce genetic resources in south-central Ontario and southwestern Quebec for use in ISAM is discussed.