Fungi provide essential ecosystem services and engage in a variety of symbiotic relationships with trees. In this study, we investigate the spatial relationship of trees and fungi at a community ...level. We characterized the spatial dynamics for above- and belowground fungi using a series of forest monitoring plots, at nested spatial scales, located in the tropical South Pacific, in Vanuatu. Fungal communities from different habitats were sampled using metagenomic analysis of the nuclear ribosomal ITS1 region. Fungal communities exhibited strong distance–decay of similarity across our entire sampling range (3–110,000 m) and also at small spatial scales (< 50 m). Unexpectedly, this pattern was inverted at an intermediate scale (3.7–26 km). At large scales (80–110 km), belowground and aboveground fungal communities responded inversely to increasing geographic distance. Aboveground fungal community turnover (beta diversity) was best explained, at all scales, by geographic distance. In contrast, belowground fungal community turnover was best explained by geographic distance at small scales and tree community composition at large scales. Fungal communities from various habitats respond differently to the influences of habitat and geographic distance. At large geographic distances (80–110 km), community turnover for aboveground fungi is better explained by spatial distance, whereas community turnover for belowground fungi is better explained by plant community turnover. Future syntheses of spatial dynamics among fungal communities must explicitly consider geographic scale to appropriately contextualize community turnover.
Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is ...predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world.
The global proportion of the most intense cyclones is increasing and it remains uncertain how damage to tropical forests will change with increasing wind speed. We compiled empirical data on the damage caused by cyclones from forests representing tropical regions worldwide to better understand the effects of wind speed, topographical exposure to wind, and tree characteristics on the proportion of damaged trees and on the probability of snapping or uprooting. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances.
Assessing how forests respond to, and recuperate from, cyclones is critical to understanding forest dynamics and planning for the impacts of climate change. Projected increases in the intensity and ...frequency of severe cyclones can threaten both forests and forest-dependent communities. The Pacific Islands are subject to frequent low-intensity cyclones, but there is little information on the effects of high intensity cyclones, or on how forest stewardship practices may affect outcomes. We assess the resistance and resilience of forests in three community-stewarded sites on the island of Tanna, Vanuatu, to the wind-related effects of 2015 Category-5 Cyclone Pam, one of the most intense cyclones to make landfall globally. Drawing on transect data established pre-and post-cyclone, we (1) test whether windspeed and tree structural traits predict survival and damage intensity, and whether this varies across sites; (2) assess post-cyclone regeneration of canopy, ground cover, seedlings, and saplings, and how community composition shifts over time and across sites. In sites that sustained a direct hit, 88 % of trees were defoliated, 34 % sustained severe damage, and immediate mortality was 13 %. Initial mortality, but not severe damage, was lower in areas that received an indirect hit and had lower windspeed. Larger trees and those with lighter wood had a higher probability of uprooting and snapping, respectively. Canopy and ground cover regenerated within three years and seedling and sapling regeneration was widespread across life histories, from pioneer to mature forest species. Three species of non-native vines recruited post-cyclone but within 5 years had largely declined or disappeared with canopy closure. Tanna's historical cyclone frequency, combined with customary stewardship practices that actively maintain a diversity of species and multiplicity of regeneration pathways, are likely responsible for the island's resistance and resilience to an intense tropical cyclone.
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•High intensity cyclones expected to increase with climate change but impacts unknown.•Effects of Category 5 cyclone examined on Pacific Island forests.•Vegetation transects across 3 contrasting Vanuatu sites surveyed over 5 years.•Forests showed high levels of both resistance and resilience.•Cyclone frequency and customary stewardship practices likely foster resilience.
Plunkett, G.M., T.A. Ranker, C. Sam & M.J. Balick (2022). Towards a checklist of the Vascular Flora of Vanuatu. Candollea 77: 105–118. In English, English and French abstracts. Vanuatu is an ...archipelago in the southwest Pacific that, to date, has no modern checklist of its flora, despite the fact that it sits in the midst of several other archipelagos of known species richness (New Caledonia, Fiji, and the Solomon Islands, among others). The present study describes our effort to establish a checklist of accepted species names that apply to taxa known or thought to occur in Vanuatu. In collating data from the Vanuatu National Herbarium (PVNH) and online databases (including virtual herbaria and database compilations), we have developed a checklist of 1,631 species of vascular plants, of which 1,262 (77.4 %) are putatively native, and 360 (22.1 %) introduced (the distributional status of the remaining 0.5 % are uncertain). Endemics represent 10.1 % of all species (native plus introduced), but 13.1 % when considering native species only. This article is linked to a dynamic checklist available online that will be continually updated, and we encourage members of the global botanical community, especially those with expertise in the taxa listed or the general floristics of the Pacific Islands, to provide corrections and additions. Received on May 11, 2021. Accepted on April 29, 2022. First published online on June 1, 2022.
En Océanie, et tout particulièrement au Vanuatu, les jardins sont les témoins d'une tradition rurale ancestrale où la plante alimentaire est à la fois une ressource indispensable, le symbole d'une ...communauté et un objet d'échange. Les Vanuatais vouent une véritable passion à leurs jardins dans lesquels ils réunissent, sélectionnent et diversifient un riche patrimoine végétal. À travers cet ouvrage abondamment illustré, le lecteur découvrira toute la diversité des plantes alimentaires océaniennes ainsi que les nombreuses espèces introduites par les grands explorateurs du xvie siècle. Chaque espèce fait l'objet d'une fiche descriptive qui présente entre autres la variabilité, la morphologie, le mode de culture et de production ainsi que les différents usages de la plante. Le cédérom qui accompagne le livre apporte des informations plus détaillées qui intéresseront le spécialiste : références bibliographiques, bases de description des ignames et des taras, photos de variabilité morphologique... Afin de mieux préserver cet exceptionnel patrimoine végétal, cet ouvrage attire l'attention d'un large public sur les jardins du Vanuatu et sur cette agriculture océanienne qui combine avec originalité différents apports multiculturels.
Sleep is paramount for optimal brain development in infants admitted to the neonatal intensive care unit. Besides (minimally) invasive technical approaches to study sleep in infants, there is ...currently a large variety of behavioral sleep stage classification methods (BSSCs) that can be used to identify sleep stages in preterm infants born <37 weeks gestational age. However, they operate different criteria to define sleep stages, which limits the comparability and reproducibility of research on preterm sleep. This scoping review aims to: 1) identify and elaborate on existing neonatal BSSCs used for preterm infants, 2) examine the reliability and validity of these BSSCs, and 3) identify which criteria are most used for different ages, ranging from 23 to 37 weeks postmenstrual age at observation.
To map the existing BSSCs, PubMed, EMBASE and Cochrane were searched for studies using a BSSC to identify sleep stages in preterm infants.
In total, 36 BSSCs were identified with on average five item categories assessed per BSSC, most frequently: eyes, body movements, facial movements, sounds, and respiratory pattern. Furthermore, validity and reliability of the BSSCs were tested in less than half of the included studies. Finally, BSSCs were used in infants of all ages, regardless the age for which the BSSC was originally developed.
Items used for scoring in the different BSSCs were relatively consistent. The age ranges, reliability, and validity of the BSSCs were not consistently reported in most studies. Either validation studies of existing BSSCs or new BSSCs are necessary to improve the comparability and reproducibility of previous and future preterm behavioral sleep studies.
•Preterm sleep stages can be assessed using behavioral classification methods (BSSCs).•Many BSSCs used in preterm infants are originally developed for term infants.•Validity and reliability are not consistently reported in BSSCs used in preterm infants.•Validated BSSCs are necessary to improve reproducibility of preterm sleep studies.•Most BSSCs comprised five frequently recurring categories of scoring items.
The three different island chains that compose the Vanuatu archipelago vary in age from 20 million years old for the western chain, five million years old for the eastern chain and to two million ...years old for the central chain where volcanoes are still active (Carney et al. 1985; Greene and Wong 1988; Hamilton et al. 2010; Monzier et al. 1997). The local flora was established from three major sources: the Solomon Islands in the north, Fiji in the east and New Caledonia in the south (Mueller-Dombois and Fosberg 1998). These three sources are considered very rich and diversified botanically
Phenotypic variation in heartwood and essential‐oil characters of Santalum austrocaledonicum was assessed across eleven populations on seven islands of Vanuatu. Trees differed significantly in their ...percentage heartwood cross‐sectional area and this varied independently of stem diameter. The concentrations of the four major essential‐oil constituents (α‐santalol, β‐santalol, (Z)‐β‐curcumen‐12‐ol, and cis‐nuciferol) of alcohol‐extracted heartwood exhibited at least tenfold and continuous tree‐to‐tree variation. Commercially important components α‐ and β‐santalol found in individual trees ranged from 0.8–47% and 0–24.1%, respectively, across all populations, and significant (P<0.05) differences for each were found between individual populations. The Erromango population was unique in that the mean concentrations of its monocyclic ((Z)‐β‐curcumen‐12‐ol and cis‐nuciferol) sesquiterpenes exceeded those of its bi‐ and tricyclic (α‐ and β‐santalol) sesquiterpenes. Heartwood colour varied between trees and spanned 65 colour categories, but no identifiable relationships were found between heartwood colour and α‐ and β‐santalol, although a weak relationship was evident between colour saturation and total oil concentration. These results indicate that the heartwood colour is not a reliable predictive trait for oil quality. The results of this study highlight the knowledge gaps in fundamental understanding of heartwood biology in Santalum genus. The intraspecific variation in heartwood cross‐sectional area, oil concentration, and oil quality traits is of considerable importance to the domestication of sandalwood and present opportunities for the development of highly superior S. austrocaledonicum cultivars that conform to the industry's International Standards used for S. album.
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