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Often climatic niche models predict that any change in climatic conditions will impact species abundance or distribution. However, the accuracy of models that just incorporate climatic information to predict future species habitat use is widely debated. Alternatively, environmental conditions may simply need to be above some minimum threshold of climatic suitability, at which point, other factors drive population size. Using the example of nesting sites of loggerhead sea turtles ( Caretta caretta ) in the Mediterranean (n = 105), we developed climatic niche models to examine whether a climatic suitability threshold could be identified as a climatic indicator in order for large populations of a widespread species to exist. We then assessed the climatic suitability of sites above and below this threshold in the past (∼1900) and future (∼2100). Most large sites that are currently above the climatic threshold were above the threshold in the past and future, particularly when future nesting seasonality shifted to start 1–2 months earlier. Our analyses highlight the importance of future phenological shifts for maintaining suitability. Our results provide a positive outlook for sea turtle conservation, suggesting that climatic conditions may remain suitable in the future at sites that currently support large nesting populations. Our study also provides an alternative way of interpreting the outputs of climatic niche models, by generating a threshold as an index of a minimum climatic suitability required to sustain large populations. This type of approach offers the possibility to benefit from information provided by climate-driven models, while reducing their inherent uncertainties. [ABSTRACT FROM AUTHOR]

Highlights: [•] 25% sea turtle nesting sites are in PAs, of which 78% are MPAs. [•] 87% of sites are in the tropics, mainly hosted by developing countries. [•] Countries provide highly variable protection coverage of different turtle species. [•] 67% out of 57% nesting sites in PAs with IUCN ratification receive high protection. [•] Global species resilience needs representative species- and country-level PA coverage. [ABSTRACT FROM AUTHOR]

Global efforts to halt biodiversity loss mandate the establishment of protected areas. In the face of habitat loss and climate uncertainty, large-scale networks of protected areas connected by corridors are needed to increase the dispersal and persistence potential of biota. For example, the recent European Biodiversity Strategy for 2030 defines clear targets for identifying, establishing and integrating ecological corridors, as part of a Trans-European Nature Network. Here, we examined whether rivers could serve as such corridors, facilitating landscape connectivity (i.e. extent to which landscape facilitates or impedes species movement, exchange of genes, natal dispersal and metapopulation dynamics) among protected areas hosted within different countries in the Balkan Peninsula, southeastern Europe. To quantitatively address this question, we calculated the proportion of the river network enclosed within a protected area per country to detect patterns of protection coverage and explored the degree to which spatial connections between 1878 protected areas are supported by the river network. Acknowledging that dams hinder instream continuity, we further quantified potential loss of connections between protected areas caused by the existence of already implemented or planned dam projects upon critical river habitats of endangered fish species. Our results highlight that Balkan rivers have great potential in providing the spatial connections needed to establish landscape connectivity between most of protected areas in the region. Still, heedless hydropower growth and dissimilarities in river protection between neighboring countries remain key challenges for the evolution of a relative framework. Transnational cooperation and systematic planning of infrastructure development could be the only efficient steps towards supporting the establishment of a river-based network to reconstruct connectivity between protected areas and meet biodiversity goals. [ABSTRACT FROM AUTHOR]

The Black Sea remains one of the most fragile marine systems globally. The six countries that share the coastline of this semi-enclosed sea have declared, through the Convention on Biological Diversity and regional conventions, their intention to conserve biodiversity and increase the coverage of the protected areas. However, currently only a small proportion of the marine area is under protection. Here, we spatially delineated priority conservation sites that could ensure species protection under the impact of different threats. We developed a cumulative risk index, incorporating anthropogenic pressures related to pollution and fisheries. We then combined this information with distribution data of marine species to apply a systematic conservation planning approach. We identified eleven key areas that cover 10% of the Black Sea, the protection of which could attain realistic conservation targets. These sites are mainly located in neritic and coastal habitats, which also host a number of species that avoid the anoxic part of the ocean basin. The management and efficient protection of these key areas require international collaboration, representing the only way to alleviate the severe degradation of this sensitive, but valuable, marine system. [Display omitted] • We combined a cumulative risk index with species range data to identify key sites. • High-risk and marine biodiversity hotspots were mainly found in the neritic zone. • Eleven conservation priority areas were identified across the Black Sea. • Transboundary conservation efforts are vital to protect Black Sea marine biodiversity. [ABSTRACT FROM AUTHOR]

Flowering and pollen seasons are sensitive to environmental variability and are considered climate change indicators. However, it has not been concluded to what extent flowering phenology is indeed reflected in airborne pollen season locally. The aim of this study was to investigate, for a wide spectrum of plant species, the responsiveness of flowering to different environmental regimes and also to check for commensurate changes in the respective pollen seasons. Fourteen taxa were selected representing the families of Corylaceae, Cupressaceae, Fagaceae, Oleaceae, Pinaceae and Platanaceae. Each was studied for at least one full flowering year and in at least two sampling stations differing in elevation or direction within the period 2004–2011. Flowering observations were made 2–3 times a week, from flower differentiation to flower desiccation; >1000 daily observations were made in 225 plant individuals, in total. Data were regressed against meteorological parameters in an attempt to identify the driving factors of flowering onset and offset. Flowering dates were compared with dates of the related airborne pollen seasons per taxon; airborne pollen monitoring took place daily using a Hirst-type volumetric sampler. For all taxa, flowering started earlier at lower elevations or southern direction. Cumulative temperature proved to be the factor most significantly affecting flowering onset and end for all species (p <0.001, R 2>0.70). For the majority of the taxa examined, airborne pollen season did not coincide locally with the respective flowering periods of the selected species: flowering could precede pollen season, even for more than one month (as in C. avellana), or start after the pollen season onset (as in P. brutia). The strong sensitivity of flowering to air temperature is not the case in the respective pollen seasons. This raises questions on the relationship between flowering times and airborne pollen seasons and on the rather underestimated role of long-distance transport of pollen. Image 1 • Flowering and airborne pollen abundances were studied for 14 woody taxa. • Flowering phenology was examined in differing elevations and directions. • Flowering occurred earlier in 10 species at lower elevations or south directions. • Flowering mismatch with pollen season indicated long-distance pollen transport. • Cumulative temperature was an essential driver of flowering. [ABSTRACT FROM AUTHOR]