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Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014–2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse.

Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages-the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014-2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse.

Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014–2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse.

Studies on the reef flat of Saint-Gilles La Saline between 1987 and 2009 compared spatio-temporal variations of primary producers on two sites, Toboggan and Planch’Alizés. Toboggan (Site-T) is an oligotrophic site characterized by Acropora corals, abundant sea urchins and few primary producers. Planch’Alizés (Site-P) is a heterotrophic site, characterized by massive corals, abundant primary producers and occasional sea urchins. From shore to outer reef front, the reef flat comprises three parts: the back reef (B), the coral zone with Large coral strips (L) and the coral zone with Narrow coral strips (N). This paper (which is Part 2 in a three part series) is divided into four sections. The first (1993, 1996, and 2002) focuses on four groups of primary producers: cyanophytes; turfs (including Stegastes epilithic algal communities); encrusting coralline algae; macroalgae. Their abundance and dominant species were recorded in the three subzones, B, L and N, using 50m-line intercept transects (LITs). The second section (1998 to 2009 inclusive, on the two same sites), reports on annually monitored turfs, encrusting coralline and macroalgae on two permanent 20m LITs. These annual records extend periodic records from these same LITs from 1987, 1993, 1996 and 2002. The third section describes species richness of primary producers at the infracentimetric level in zones B, L and N in 1994. In the final section, seasonal variability is documented as changes in the biomass of dominant macroalgae reported monthly over a period of seven months (1993-94). In 1993-2002, primary producers were dominant at P (average ~ 60%) but inconspicuous at T (~5%). In terms of relative cover, turfs and macroalgae were the dominant forms at both sites (75% turfs, 10% macroalgae at T ; 24% t. and 52% m. at P). On both sites, cyanophytes significantly decreased over time. Among turfs, fine filamentous turfs were prevalent on the back reef on both sites, and also on the, narrow outer coral zone at P. Stegastes turf territories dominated both coral zones at Site-T (L and N), but only the L coral zone at Site-P. Encrusting coralline algae were sparse at Site-T but locally abundant at Site-P, where they increased significantly from 1993 to 1996 in both coral zones. There was a major decrease in macroalgae between 1993 and 2002 at P. There were marked differences in the trajectories of decline of the dominant soft macroalgae (Hypnea valentiae, Padina spp, Dictyota spp, Turbinaria ornata and Gracilaria canaliculata). Seventy six primary producer species were recorded in the infracentimetric study (52 species at T and 67 at P). Different algae dominated different areas at both sites. At Toboggan, locally dominant species were the small Gelidium pusillum, an unidentified Melobesiae, Jania adhaerens, the encrusting corallines Hydrolithon onkondes and Lobophora variegata, the turfs Polysiphonia mollis and Anotrichium tenue (mainly in Stegastes territories), Jania adhaerens and Dictyosphaeria verluysii. At P, the dominants were Mesophyllum erubescens encrusting dead hard substrates and decimetric bioclasts in the back reef (B), where they form numerous rhodoliths. In the P coral zones, the dominant taxa were Lyngbya majuscula (cyanobacteria) followed by Hydrolithon onkodes, Blennothrix cantharidosma and Lithophyllum kotschyanum. Jania adhaerens, Hydrolithon onkodes and Gelidiella acerosa were dominant in the narrow coral zone (N). The local composition of the algal community appears to be more related to geomorphological zones and the presence or absence of the territorial Stegastes fish than to environmental differences between T and P. There was strong seasonal change in macroalgae biomass in 1993-4. On the back reef of both sites, peak biomass was due to Hypnea valentiae in February, when it is significantly greater than it was in January. Dictyosphaeria verluysii was dominant and highly visible at Site-T, but extremely rare and hidden bel

AFOCEL commenced a breeding programme for Eucalyptus in 1972 after several tentative species introductions had been undertaken by the Administration Porestiere Francaise. Introductions of Eucalyptus into France had been stopped previously because of the exceptionally cold winter of 1956. Interest in eucalypt plantations for pulpwood production increased following the success of trials established near Toulouse, in the south of France (Marquestuat et al. 1978.Marien and Cauvin 1984) and was encouraged by more than a century of growth of eucalypts as ornamentals near the Mediterranean coast. The good growth rates and survival of species such as Eucalyptusdatrympleana. E. viminalis,E. macarthuriiand E. nitens as well as the slower growing, but more frost resistant species such as E. gunnii resulted in the development of an intensive eucalypt breeding programme (Cauvin 1984; Cauvin et at. 1987) and approximately 400 hectares of industrial plantings of clonal selections had been established prior to the devastating frost of 1985 (Figure 1). Up until the winter of 1985,considered as extreme as that of 1956.AFOCEL had proposed a group of clones for the industrial plantations which principally comprised E. gunnii x dalrympleana hybrids. These clones represented what, at the time, was considered an acceptable compromise between vigour and frost resistance given the low probability of another extreme winter. However, since the frost of 1985 which killed even the more frost resistant species such as E. gunnii to ground level (potts and Potts 1986). industrial plantings were stopped and AFOCEL has since concentratedon selection of eucalypt clones for extreme frost resistance. AFOCEL is selecting close to the natural limits of the frost resistance of the genus and the challenge is to develop plants which are resistant to relatively infrequent, unpredictable extreme frost temperatures; yet suitably productive to remain economically competitive with more traditional species.

AFOCEL commenced a breeding programme for Eucalyptus in 1972 after several tentative species introductions had been undertaken by the Administration Porestiere Francaise. Introductions of Eucalyptus into France had been stopped previously because of the exceptionally cold winter of 1956. Interest in eucalypt plantations for pulpwood production increased following the success of trials established near Toulouse, in the south of France (Marquestuat et al. 1978.Marien and Cauvin 1984) and was encouraged by more than a century of growth of eucalypts as ornamentals near the Mediterranean coast. The good growth rates and survival of species such as Eucalyptusdatrympleana. E. viminalis,E. macarthuriiand E. nitens as well as the slower growing, but more frost resistant species such as E. gunnii resulted in the development of an intensive eucalypt breeding programme (Cauvin 1984; Cauvin et at. 1987) and approximately 400 hectares of industrial plantings of clonal selections had been established prior to the devastating frost of 1985 (Figure 1). Up until the winter of 1985,considered as extreme as that of 1956.AFOCEL had proposed a group of clones for the industrial plantations which principally comprised E. gunnii x dalrympleana hybrids. These clones represented what, at the time, was considered an acceptable compromise between vigour and frost resistance given the low probability of another extreme winter. However, since the frost of 1985 which killed even the more frost resistant species such as E. gunnii to ground level (potts and Potts 1986). industrial plantings were stopped and AFOCEL has since concentratedon selection of eucalypt clones for extreme frost resistance. AFOCEL is selecting close to the natural limits of the frost resistance of the genus and the challenge is to develop plants which are resistant to relatively infrequent, unpredictable extreme frost temperatures; yet suitably productive to remain economically competitive with more traditional species.