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Ecological research is highlighting different kinds of issues concerning biodiversity conservation policies. Based on a historical study on protected areas, we suggest that these issues are not caused by a lack of knowledge or technical tools but rather by a misuse of ecological knowledge during the implementation of policy instruments in part driven by a lack of understanding of the mechanisms underlying the policymaking process. We believe that determining the conditions under which ecological science can enlighten policy decisions is now necessary to address current biodiversity conservation issues. This can only be achieved through the promotion of interdisciplinary research. [ABSTRACT FROM AUTHOR]

The effects of climate change on coastal risk factors are increasing due to both rising sea levels and increasingly intense coastal floodings. However, these changes are only just beginning to be incorporated into planning strategies for coastal economies and land use in France. Recent coastal storms marked the turning point, and public authorities have now started to revise coastal management legislation, stating that the managed retreat of settlements and infrastructure is the preferred strategy to adapt to climate change. To date, this managed retreat has almost exclusively been discussed in relation to the current political, social, and economic obstacles that make it difficult to relocate equipment and houses inland. Here, we add to this discussion by depicting how the careful ecological restoration of dunes and salt marshes on land made available by managed retreat could overcome some of these obstacles. First, we describe three possible strategies to adapt to sea‐level rise as well as the maladaptation of the current strategy. Then, we focus on the limitations and advantages of ecological restoration in terms of managed retreat and vice versa. Finally, we depict how a new kind of land lease, introduced in draft legislation, can help tackle the multitemporal and multispatial issues that currently hinder managed retreat. [ABSTRACT FROM AUTHOR]

Climate change obliges societies to develop adaptive strategies in order to maintain sustainable management of resources and landscapes. However, the development and implementation of these strategies require dialogue between researchers and policy-makers about what they understand for adaptation. This dialogue can be hindered by language differences, the hidden agendas, and conflicting concerns of those involved. In this research study, we explored the mechanisms that underlie the implementation process of assisted migration (AM), an adaptation strategy that aims to limit the impact of climate change. We conducted a comparative analysis of 80 semistructured interviews with actors in the forestry sectors in Canada and France. In Canada, our results show a division between the provinces strategies, causing a debate about AM because researchers are wary of the geoengineering and economic arguments that frame AM in areas where the effects of climate change remain unclear. In contrast, we found that the observation of climate impacts is a strong trigger for the application of AM despite an awareness of its associated risks. In France, we explained the absence of AM implementation by a lack of information flow between research and foresters regarding the concept of AM, a cultural attachment of French foresters to their forest landscapes and that climate change effects are not clear yet. Clarity on what implies a true ecological engineering approach in ecological restoration can help maintaining adaptive actions like AM within the general scope of ecosystem management and minimize simplistic applications of adaptation strategies because of climate change. [ABSTRACT FROM AUTHOR]

Restoration programs need to increasingly address both the restitution of biodiversity and ecosystem services and the preparation of habitats for future climate change. One option to adapt habitats to climate change in the temperate zone is the translocation of southern populations to compensate for climate change effects-an option known as assisted migration ( AM). Although AM is widely criticized for endangered species, forest managers are more confident that tree populations can be translocated with success because of previous experiences within native ranges. Here, we contend that translocations of tree populations are also subject to uncertainties, and we extract lessons for future programs of AM within species ranges from a well-documented failed case of population translocation of Pinus pinaster Ait. in Europe. The failure of these translocations originated from the unawareness of several unpredictable ecological and social events: cryptic maladaptation of the introduced populations, underestimation of climate variability differences between the source and target sites, and complexity in the management schemes, postponing decisions that could have been undertaken earlier. Under the no-analog conditions that are expected with climate change, management decisions need to be made with incomplete data, implying that a certain degree of maladaptation should always be expected when restoring plant populations from local or external seed sources. [ABSTRACT FROM AUTHOR]

Aim To examine mechanisms related to the formation of hybrid zones between the Mediterranean narrow-leaved ash tree Fraxinus angustifolia Vahl and the common ash Fraxinus excelsior L., a mostly temperate tree species, at the continental scale. Location Temperate and Mediterranean Europe and the western part of the Black Sea basin. Methods We used species distribution models to determine the potential zones of sympatry between the two species, which remain largely unknown. In addition, we analysed 58 populations and 456 samples of ash tree that spanned most of the distribution of the two species across Europe, and included both parental species and selected hybrid populations. Levels of hybridization in the 58 populations were estimated using 19 nuclear microsatellite loci, including six anonymous nuclear single sequence repeat ( SSR) markers and 13 recently developed single sequence repeats from expressed RNA sequence tags ( EST- SSRs). Results Bayesian assignment supported the notion of two separate gene pools regardless of the type of marker used, which suggest an ancient population structure. Populations located within the predicted overlap zones had intermediate levels of admixture with a tendency for hybrid populations to occur towards temperate areas. Selection analyses indicated that six of the EST- SSRs had been subjected to stabilizing selection whereas two others had been subjected to directional selection. Results of spatial filtering on the allele frequencies of the loci under directional selection suggest that the number of days of frost and summer temperatures are both ecological factors that can limit the extent of the hybrid zone. Moreover, areas associated with known or predicted hybrid zones showed abrupt changes in allele frequencies compared with the periphery of the distributions. Main conclusions Our analyses suggest that the hybrid structure in these closely related ash species is ancient and asymmetric and that climate-driven selection, in particular cold weather, can potentially limit the extent of hybrid populations. [ABSTRACT FROM AUTHOR]

One of the greatest challenges of forest restoration is the choice of appropriate plant material that is adapted to local environments, provides the desired ecological services, and does not compromise the local biodiversity. Plant restoration programs use native seeds, a mixture of local and introduced seeds of the same species or allopatric species. However, restoration programs rarely use local hybrid individuals if a local species exhibits natural hybridization. Hybridization is an important evolutionary process that can result in new genotypic combinations that might be suited better to the target habitat than the parental species and allow adaptation to rapid environmental change. European forests are generally under strict legal regulations so that only certified seeds can be used for their restoration. The European certification procedure for seeds from forest trees has been devised to commercialize clearly identified species with known adaptation to a given area. Natural hybrids, for which taxonomic status is uncertain and fitness is generally unknown, are excluded, which is not the case of artificial hybrids because they have been previously tested in the field. Here we discuss the pressing need to include natural hybrid populations as a source of certified seeds for restoration purposes. Using the example of two ash species and their well-adapted hybrids along the Loire River in France, we show why European forest guidelines must be made more flexible to allow the provision of stable ecosystem services. [ABSTRACT FROM AUTHOR]

The two closely related ash species Fraxinus excelsior L. (common ash) and Fraxinus angustifolia Vahl (narrow-leaved ash) have a broad contact zone in France where they hybridize. However, little is known about the local structure of hybrid zone populations and the isolation mechanisms. We assessed the potential effect of floral phenology on the structure of a riparian ash hybrid zone population in central France. The distribution of flowering times was unimodal and lay between the flowering periods of the two species. Using microsatellite markers, we detected isolation by time, which has possibly originated from assortative mating. Multivariate analyses indicated that morphological variation is not distributed at random with respect to flowering times. Spatial autocorrelation analyses showed that temporal and spatial patterns were tightly linked. Interestingly, despite the fact that the population shows isolation by time, neighbourhood size and historical dispersal variance (&sigmacirc; = 63 m) are similar to those detected in pure stands of F. excelsior where individuals flower rather synchronously and hermaphrodites are not the most frequent sexual type. Trees flowering at intermediate dates, which comprised the majority of the population, produced on average more flowers and fruits. We detected no significant differences in floral parasite infections relative to reproductive timing, although there was a tendency for late flowering trees to suffer from more gall attack. We discuss the impact of temporal variation in fitness traits and their possible role in the maintenance of the hybrid zone. [ABSTRACT FROM AUTHOR]

Wild cherry (Prunus avium L.), a partially asexual self‐incompatible forest tree, shows heterozygote excess, which is a poorly studied phenomenon. In three natural populations, we found significant heterozygote excess at almost all investigated loci (eight microsatellites and markers for the self‐incompatibility locus). We examined four hypotheses to account for this observed heterozygote excess. First, negative FIS can result from a lack of selfed progeny in small populations of outcrossing species. A second explanation for negative FIS is selection during the life cycle of the most heterozygous individuals. A third explanation is negative assortative mating when reproduction occurs between individuals bearing phenotypes more dissimilar than by chance. The last explanation for negative FIS relies on asexual reproduction. Expectations for each hypothesis were tested using empirical data. Patterns of FIS differed among loci. Nevertheless, our experimental results did not confirm the small sample size hypothesis. Although one locus is probably under a hitch‐hiking effect from the SI locus, we rejected the effect of the self‐incompatibility locus for the genome as a whole. Similarly, although one locus showed a clear pattern consistent with the selection of heterozygous individuals, the heterosis effect over the whole genome was rejected. Finally, our results revealed that clonality probably explains significant negative FIS in wild cherry populations when considering all individuals. More theoretical effort is needed to develop expectations and hypotheses, and test them in the case of species combining self‐incompatibility and partially asexual reproduction. [ABSTRACT FROM AUTHOR]

Polygamy (including trioecy and subdioecy), the co-occurrence of males, hermaphrodites, and females in natural populations, is a rare and poorly studied breeding system expressed in Fraxinus excelsior L. (Oleaceae), a wind-pollinated tree. Here we investigate siring ability of pollen from male vs. hermaphrodite individuals to better understand this sex polymorphism. We conducted single-donor and two-donor pollination experiments and compared both fruit set and seed siring success, assessed with polymorphic microsatellite markers, of male and hermaphrodite individuals. Single pollen donor crosses allowed us to verify the male function of hermaphrodites. However, pollen from hermaphrodites was much less proficient than male pollen, with males siring 10 times as many fruits in single donor pollination treatments. This result was strengthened by the surprisingly low reproductive success of hermaphrodites in pollen competition conditions: of the 110 seedlings analyzed three were selfed and only one was sired by the hermaphrodite donor. The remaining 106 were sired by the male pollen donor. These results raise the question of the maintenance of male fertility in hermaphrodites in Fraxinus excelsior. Male function of hermaphrodites in this species now needs to be assessed under field conditions. [ABSTRACT FROM AUTHOR]

Abstract We analysed genetic variation within and between populations of the common ash from Bulgaria in order to extract biological information useful in the context of conservation management of eastern European genetic resources of noble hardwood species. A total of 321 trees from three regions of Bulgaria were typed at six highly polymorphic microsatellite loci. Analysis of within-population inbreeding suggests an upper boundary value of 2.7% for the selfing rate. Significant spatial genetic structure consistent with models of isolation by distance was detected within four out of 10 populations as well as among populations. Estimates of neighbourhood size in the range 38–126 individual trees were obtained based on spatial genetic structure analyses at either the intrapopulation or interpopulation level. Differentiation among populations explained only about 8.7% of total genetic diversity. These results are discussed in comparison with data from social broad-leaved species such as oak and beech. [ABSTRACT FROM AUTHOR]

Assisted colonization (AC), or the intentional translocation of populations to compensate for risks related to climate change, is receiving increasing attention. It has been recently suggested by Kreyling et al. (2011) that rather than relocating endangered species, a focus should be placed on local adaptations of foundation or keystone species, and that these local ecotypes should be moved within their own range. Hence, this type of relocation could be applied with minimal risk in many restoration efforts. We think that caution is needed when considering the translocation of these foundation species, even within their range. Many recent studies have shown that foundation species can influence community structure and ecosystem processes through heritable traits, which suggests a genetic basis for ecosystem services. Thus, the translocation of different genotypes of foundation species might lead to unexpected results of colonization and might not be as 'predictable' as Kreyling et al. have argued. Here, in our response, we stress how AC of foundation species can have important evolutionary consequences that might be impossible to reverse. We propose, whenever possible, (1) to favor population mixes of the foundation species to minimize the potential negative effects of specific genotypes; and (2) to collect from adjacent populations along ecological clines of the foundation species to mimic natural processes of migration under climate change. [ABSTRACT FROM AUTHOR]