•A large custom cryogen-free cryostat has been designed and built in order to operate the CUORE detector.•The CUORE cryostat has a 1 m3 experimental volume and is able to host a tonne-scale ...bolometric detector.•The CUORE cryostat guarantees a low noise and low radioactivity environment, needed to search for 0nbb.•The CUORE detector has been cooled down to 8.3 mK and steadily operated at 15 mK, proving the success of the cryostat.
The CUORE experiment is the world’s largest bolometric experiment. The detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of ∼10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE.
•We assessed the biodiversity value of old fields for farmland natural enemies (NEs).•Old fields supported diverse NE assemblages, including endemic species.•Old fields are more habitable than ...dominant vineyards to NEs in natural remnants.•Specialists may benefit more from the presence of old fields than generalists.•Old fields increase farmland compositional diversity, which enhances biodiversity.
Spatially heterogeneous agricultural landscapes can support high levels of biodiversity. However, our understanding of the biodiversity value of most landscape elements and their role in the farmland mosaic is limited. We assessed the potential of old fields, a common small-scale feature of farmland in the Cape Floristic Region (CFR), for maintaining arthropod natural enemy (NE) diversity. We also assessed how habitable they are to NEs occurring in remnant fynbos vegetation, compared to the dominant surrounding vineyards. Furthermore, we compared habitat preferences of hymenopteran parasitoids, which are mostly habitat and trophic specialists, with those of generalist predatory arthropods. NE abundance and richness was as high in old fields as in natural vegetation, and was significantly higher than in vineyards. Old fields provided high plant diversity and prey abundance which were positively correlated with NE diversity. Ten out of eleven species of conservation significance assessed here occurred in old fields, including Western Cape and South African endemics, rare and uncommon species. Old field assemblages complemented fynbos and vineyard assemblages, and contained many unique species. They also shared many more species with natural assemblages than did vineyards, representing a more habitable transformed landscape element than cultivated areas for most species. Parasitoids showed greater habitat specificity than predators, and are likely to benefit more from the positive effect of increased habitat heterogeneity. Our results show that small-scale non-natural landscape features can provide additional resources, increase compositional heterogeneity and may help soften the overall agricultural mosaic for arthropod NEs in the CFR. Understanding the value of different landscape mosaic elements is an important step towards a broader landscape-scale approach to farmland biodiversity conservation.
Mutualisms between invasive ants and honeydew-producing Hemiptera have the potential to result in unusually high population levels of both partners, with subsequent major changes to ecosystem ...composition and dynamics. We assessed the relationship between the invasive ant,
Pheidole megacephala
, and its hemipteran mutualists,
Dysmicoccus
sp. and
Pulvinaria urbicola
, on Cousine Island, Seychelles. We also assessed the impacts of the mutualism on the condition of the hemipteran host plant,
Pisonia grandis
, a native and functionally important tree species. There was a strong positive relationship between
Ph. megacephala
activity and hemipteran abundance, and the exclusion of ants from
Pi. grandis
resulted in a significant decline in
Pu. urbicola
abundance. High abundance of the mutualists was strongly associated with damage to the
Pi. grandis
forest. This indicates that the mutualism is contributing to the massive increase in the population levels of the mutualist species, and is intensifying their impacts on the island. The widespread trophobiosis and its associated high densities of mutualists pose serious threats to the ecosystem, highlighting the need to control the ant and associated hemipteran populations.
The Cape Floristic Region (CFR), South Africa, is a biodiversity hotspot challenged by intensive wine production. Innovative approaches are being explored to optimize wine production without ...compromising biodiversity. As organic farming enhances biodiversity conservation in many other regions, the aim here was to assess the potential of organic vineyard management for conserving CFR soil surface arthropod diversity. Pitfall traps were used to sample arthropods in three study areas, each of which included an organic vineyard, an integrated vineyard and a natural vegetation reference habitat. Overall arthropod morphospecies richness was highest in natural sites, followed by organic vineyards and then integrated vineyards. The same trend was seen for predators, saprophages and phytophages. The ability of organic vineyards to sustain more morphospecies than integrated vineyards were partially due to higher non-crop vegetation complexity and less intense management in the organic vineyards. Arthropod assemblages were similar in organic and integrated vineyards, while both land-uses differed greatly from natural sites. Variation among natural vegetation assemblages in different study areas was also much greater than among assemblages of cultivated sites. Organic vineyard management has the potential to make an important contribution to arthropod conservation in the CFR at the field scale. However, at the landscape scale, natural habitat supports a much wider variety of morphospecies, and the preservation of natural fragments in the vineyard landscape may be the most effective measure to increase biodiversity in the winelands.
Effective management of invasive ants is an important priority for many conservation programs but can be difficult to achieve, especially within ecologically sensitive habitats. This study assesses ...the efficacy and nontarget risk of a precision ant baiting method aiming to reduce a population of the invasive big-headed ant
Pheidole megacephala
on a tropical island of great conservation value. Area-wide application of a formicidal bait, delivered in bait stations, resulted in the rapid decline of 8 ha of
P. megacephala
. Effective suppression remained throughout the succeeding 11-month monitoring period. We detected no negative effects of baiting on nontarget arthropods. Indeed, species richness of nontarget ants and abundance of other soil-surface arthropods increased significantly after
P. megacephala
suppression. This bait station method minimized bait exposure to nontarget organisms and was cost effective and adaptable to target species density. However, it was only effective over short distances and required thorough bait placement. This method would therefore be most appropriate for localized
P. megacephala
infestations where the prevention of nontarget impacts is essential. The methodology used here would be applicable to other sensitive tropical environments.
Effective management of invasive ants is an important priority for many conservation programs but can be difficult to achieve, especially within ecologically sensitive habitats. This study assesses ...the efficacy and nontarget risk of a precision ant baiting method aiming to reduce a population of the invasive big-headed ant
Pheidole megacephala
on a tropical island of great conservation value. Area-wide application of a formicidal bait, delivered in bait stations, resulted in the rapid decline of 8 ha of
P. megacephala
. Effective suppression remained throughout the succeeding 11-month monitoring period. We detected no negative effects of baiting on nontarget arthropods. Indeed, species richness of nontarget ants and abundance of other soil-surface arthropods increased significantly after
P. megacephala
suppression. This bait station method minimized bait exposure to nontarget organisms and was cost effective and adaptable to target species density. However, it was only effective over short distances and required thorough bait placement. This method would therefore be most appropriate for localized
P. megacephala
infestations where the prevention of nontarget impacts is essential. The methodology used here would be applicable to other sensitive tropical environments.
Ants can disrupt the natural biological control of serious hemipteran pests by interfering with natural enemies, resulting in a change in ecosystem functioning. We focus here on interference by a ...highly invasive ant
Pheidole megacephala
on the regulation of a tree destroying hemipteran scale insect
Pulvinaria urbicola
on Cousine Island in the Seychelles archipelago, a tropical island ecosystem. We show how a diverse natural enemy assemblage contributes substantially to the collapse of the ant-scale mutualism following managed ant suppression. Natural enemy abundance and species richness increased significantly after ant suppression, with varying responses among the different functional guilds. Primary parasitoids coexisted with tending ants before ant suppression, but could not regulate the enormously high scale densities alone. After ant suppression, a significant increase in predators caused a collapse of the scale population. Guilds external to the mutualism were also affected, with primary parasitoids of various non-hemipteran taxa also increasing, which contributed significantly to the recovery of the community to its pre-invasion composition. Our results highlight the far-reaching and pervasive effects of the hemipteran-tending invasive ant within the natural enemy assemblage. In turn, we also illustrate the potential to restore the tropical ecosystem by encouraging an array of natural enemies through precision management of the ant.
•Diverse herbaceous cover crops promoted vineyard arthropod diversity.•It favoured all taxa, feeding guilds and organisms in different microhabitats.•No effect was detected for agrochemicals used in ...a sensitive integrated approach.•Individual management practices influenced arthropods more than overall farm regime.
Agricultural intensification threatens biodiversity, requiring a shift to agroecological farming. Identifying locally-specific management practices that can effectively enhance biodiversity can help guide farmland conservation efforts. We assess the effect of management practices and environmental variables on arthropod diversity under varying vineyard management regimes in a South African biosphere reserve. We also determine whether the implementation of these practices and their combined effect on arthropods differ between integrated and organic vineyards. Arthropod morphospecies richness and evenness were assessed for different taxonomic groups (spiders, beetles, and true bugs), in different positions in the crop (ground level, on cover crops, and on vine foliage) and for different feeding guilds (herbivores, detritivores, and predators). Percentage herbaceous vegetation cover had a consistent positive effect on morphospecies richness across taxa, microhabitats, and guilds. Other vegetation-related variables, such as volume of plant litter, plant species richness, and plant height positively influenced several of the biodiversity responses. We did not detect any negative effect of agrochemicals used in an integrated approach, or a strong effect of overall farming approach (organic vs. integrated) on the species richness or evenness of any of the focal taxa, sampled positions, or guilds. These results indicate that the maintenance of dense and diverse cover crops is a strategic way to enhance vineyard arthropod diversity where other management practices are already implemented sensitively. This highlights that minimal adjustment of management practices can greatly benefit farmland biodiversity conservation and is in keeping with the ethos of the concept of a biosphere reserve.
Agriculture is a major contributor to habitat transformation, homogenising biological communities, and reducing biodiversity at local and regional scales. Over time, biotic homogenisation causes ...regional biotas to become genetically, taxonomically, and functionally similar, impacting the functioning and resilience of natural and agricultural systems. Here, we assessed alpha and beta diversity, trait diversity, and trait composition of spider and beetle assemblages in biodiversity-friendly vineyards and natural fynbos vegetation (a low-growing sclerophyllous vegetation type) in the Cape Floristic Region biodiversity hotspot to evaluate the influence of viticulture on large-scale patterns of arthropod diversity. Transects spanning from vineyards into fynbos were used to analyse differences in arthropod assemblages between the two biotopes. Spider species richness was significantly higher in fynbos compared to vineyards, but both systems supported relatively high spider and beetle alpha diversity. Spider beta diversity did not differ between the systems, but beetle beta diversity was significantly lower in vineyards. This difference was due to a lower level of assemblage nestedness, whereas beetle species replacement was similar in vineyards and fynbos. Only spider trait richness and beetle trait divergence were significantly lower in vineyards compared to fynbos. Assemblage composition of both taxonomic groups differed between biotopes, due to different species trait associations with each biotope. Plant-dwelling spiders and small-bodied beetles were strongly positively associated with fynbos, and predatory beetles with vineyards. Common spiders and predatory beetles were strongly negatively associated with fynbos. Our results indicate that vineyards support high arthropod diversity when compared to the natural vegetation. This supports the concept that sensitively managed agroecosystems can maintain species-rich assemblages at different spatial scales.
•Differences in diversity measures between vineyards and natural habitat were subtle.•Arthropod assemblage in vineyards greatly altered compared to natural vegetation.•Sensitively managed systems support arthropod diversity at different spatial scales.
The CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this ...technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-number-violating process: ^{130}Te neutrinoless double-beta decay. Examining a total TeO_{2} exposure of 86.3 kg yr, characterized by an effective energy resolution of (7.7±0.5) keV FWHM and a background in the region of interest of (0.014±0.002) counts/(keV kg yr), we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of T_{1/2}^{0ν}(^{130}Te)>1.3×10^{25} yr (90% C.L.); the median statistical sensitivity of this search is 7.0×10^{24} yr. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find T_{1/2}^{0ν}(^{130}Te)>1.5×10^{25} yr (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find m_{ββ}<(110-520) meV, where the range reflects the nuclear matrix element estimates employed.
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