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Bushfire severity mapping and analysis for Queensland’s Gondwana Rainforests World Heritage Area properties following wildfires in 2019/20 was found to under-predict the ecological impact within closed-canopy rainforests, biasing against the prioritisation of rainforest-dependent threatened fauna for assessment and the allocation of recovery resources. By incorporating the fire tolerance of vegetation communities mapped within the bushfire extent, bushfire severity can be extended to predict the potential ecological impact of each severity class on ecosystems, and priority species. Prioritising threatened species based on potential ecological impact rather than fire severity alone allows post-fire survey and monitoring to be better targeted to those species likely most severely impacted. It also allows resources and recovery actions to be directed towards those areas of greatest concern, which may not have suffered the worst bushfire severity.

Aims: Quantifying the relative importance of the mechanisms that drive community assembly in forests is a crucial issue in community ecology. The present study aims to understand the ways in which niche-based and spatially based processes influence community assembly in areas in different climatic conditions and how these processes change during the transition from seedling to adult. Methods: In this study, we investigated how taxonomic and phylogenetic beta diversity in seedling and adult stages of forest trees change across three elevational transects in tropical, subtropical and subalpine forests in Southwest China, and the relationships of these changes to the environment and inter-site distances. We quantified the relative contribution of environmental conditions and spatial distribution to taxonomic and phylogenetic beta diversity of both seedling and adult life stages along each elevational transect. We also quantified the taxonomic and phylogenetic similarity between seedlings and adult trees along elevations. Important Findings: Taxonomic and phylogenetic beta diversity of both seedlings and adult trees increased with an increase in both environmental distance and spatial distance in all three transects. On both taxonomic and phylogenetic levels, the effects of environmental filtering and spatial disposition varied between life stages and among forest types. Phylogenetic similarity between seedlings and adult trees increased with elevation, although the taxonomic similarity did not show clear elevational patterns. Our results suggest that the relative contribution of niche-based and space-based processes to taxonomic and phylogenetic assemblages varies across major plant life stages and among forest types. Our findings also highlight the importance of ontogenetic stages for fully understanding community assembly of long-lived tree species.

Aim There is little consensus as to whether stratification of arthropods between canopy and understorey in tropical and subtropical forests is commonplace and if the magnitude of stratification changes across different elevations and latitudes. We investigated broad-scale patterns of vertical stratification of moths collected from extensive cross-continental fieldwork in a variety of forest types, climates, elevations, latitudes and areas with differing biogeographical history.n Location Tropical and subtropical rain forest in eastern Australia; tropical, subtropical and subalpine forest in Yunnan Province, China; and tropical rain forest in Panama, Vietnam, Brunei and Papua New Guinea.n Methods Night-flying moths were trapped from the upper canopy and understorey. We generated a total of 64 data sets to quantify vertical stratification of moths in terms of their species richness, using coverage-based rarefaction, and assemblage composition, using standardized hierarchical beta diversity. Based on the average temperature lapse rate, we incorporated latitudinal differences into elevation and generated 'corrected' elevation for each location, and analysed its relationships with the magnitude of stratification.n Results We found consistent differences between canopy and understorey assemblages at almost all rain forest locations across corrected elevational gradients. The magnitude of vertical stratification in species richness did not change with increasing corrected elevation. In contrast, the difference in assemblage composition increased with increasing corrected elevation in the Northern Hemisphere, while the opposite, albeit weak, trend was found in the Southern Hemisphere.n Main conclusions Clear vertical stratification was evident in moth assemblages regardless of elevation and latitude. However, the degree to which assemblages are stratified between canopy and understorey is not uniformly related to elevation and latitude. Inconsistencies in the magnitude of vertical stratification between the Northern and Southern Hemisphere, may reflect, on one hand, deep-time biogeographical differences between the land masses studied and, on the other, place-to-place differences in resource availability underpinning the observed moth assemblages.

Investigation of the spatial distribution of biodiversity among communities or across habitats (beta diversity) is often hampered by a scarcity of biological survey data. This is particularly the case in communities of high floristic diversity, such as the subtropical rainforests of eastern Australia. In contrast, there is excellent spatial coverage of environmental data for this region, such as geology, elevation and climate data. Generalized dissimilarity modelling was used in this study to combine biological survey data and environmental data grids for the investigation and prediction of floristic turnover among vegetation communities at a regional scale. Generalized dissimilarity modelling identified four environmental predictors of floristic turnover in the study region, all of which are linked with moisture stress: radiation of the driest quarter, precipitation of the driest period of the year, slope and aspect. Ten land classes representing largely homogeneous floristics and environment were identified and mapped for the region, allowing significantly greater discrimination than currently available mapping for this region. With increases in evapotranspiration and moisture stress predicted as a result of climate change, these results may allow future floristic shifts to be assessed in relation to regional-scale gradients in floristic turnover.

Full floristic data, tree demography, and biomass estimates incorporating non-tree lifeforms are seldom collected and reported for forest plots in the tropics. Established research stations serve as important repositories of such biodiversity and ecological data. With a canopy crane setup within a tropical lowland rainforest estate, the 42-ha Daintree Rainforest Observatory (DRO) in Cape Tribulation, northern Australia is a research facility of international significance. We obtained an estimate of the vascular plant species richness for the site, by surveying all vascular plant species from various mature-phase, remnant and open vegetation patches within the site. We also integrate and report the demography and basal areas of trees ≥ 10 cm diameter at breast height (dbh) in a new 1-ha core plot, an extension to the pre-existing forest 1-ha plot under the canopy crane. In addition, we report for the canopy crane plot new demography and basal areas for smaller-size shrubs and treelets subsampled from nine 20 m2 quadrats, and liana basal area and abundance from the whole plot. The DRO site has an estimated total vascular plant species richness of 441 species, of which 172 species (39%) are endemic to Australia, and 4 species are endemics to the Daintree region. The 2 x 1-ha plots contains a total of 262 vascular plant species of which 116 (1531 individuals) are tree species ≥ 10 cm dbh. We estimate a stem basal area of 34.9 m2 ha-1, of which small stems (tree saplings and shrubs We present a floristic checklist, a lifeform breakdown, and demography data from two 1-ha rainforest plots from a lowland tropical rainforest study site. We also present a meta-analysis of stem densities and species diversity from comparable-sized plots across the tropics.

著者人数: 16人, Number of authors: 16, 資料番号: PA1010040000

This study describes the floristics and structure of a 0.95-ha lowland tropical rainforest plot at the Australian Canopy Crane Research Facility at Cape Tribulation, Queensland. Five years of post-cyclonic change in forest floristics and structure following the passage of Tropical Cyclone 'Rona' in February 1999 are examined. Local and regional variation in tropical rainforest is examined in comparison with other lowland plots established nearby and mid-elevation plots located elsewhere in north Queensland at Eungella, Paluma and the Atherton Tablelands. These plots are placed in a broader Australasian context along with lowland rainforest plots at Baitabag and Oomsis, Papua New Guinea. The 2005 survey found 680 stems of 82 species >= 10 cm d.b.h. on the crane plot, an increase of 30.3% in stems and 16.4% of species in the 5 years since the previous survey. The most abundant families were Meliaceae, Euphorbiaceae, Lauraceae, Myrtaceae and Apocynaceae and the most abundant species were Cleistanthus myrianthus, Alstonia scholaris, Myristica insipida, Normanbya normanbyi and Rockinghamia angustifolia. Temporal floristic and structural variation suggests that the crane site remains in an active stage of post-cyclonic recovery. Local spatial variability in floristics and structure at Cape Tribulation exceeded the variation exhibited by a single plot over a period of 5 years, despite the impact of Cyclone Rona. This finding suggests a high degree of temporal stability within this stand of rainforest despite frequent catastrophic disturbances. The rainforests of Cape Tribulation constitute a relatively unique floristic community when observed in an Australasian context. Variation in rainforest community composition across the region shows the importance of biogeographical connections, the impacts of local topography, environmental conditions and disturbance history.

Local species diversity of insect herbivores feeding on rainforest vegetation remains poorly known. This ignorance limits evaluation of species extinction patterns following various deforestation scenarios. We studied leaf-chewing insects feeding on 59 species of woody plants from 39 genera and 18 families in a lowland rainforest in Papua New Guinea and surveyed all plants with a stem diameter at breast height of ≥ 5c m in a1 - ha plot within the same area. We used two extrapolation methods, based on randomized species-accumulation curves, to combine these two data sets and estimate the number of species of leaf-chewing herbivores feeding on woody plants from the 1-ha area. We recorded 58,483 feeding individuals from 940 species of leaf-chewing insects. The extrapolation estimated that there were 1567-2559 species of leaf-chewing herbivores feeding on the 152 plant species from 97 genera and 45 families found in 1 ha of the forest. Most of the herbivore diversity was associated with plant diversity on the familial and generic levels. We predicted that, on average, the selection of 45 plant species each representing a different family supported 39% of all herbivore species, the 52 plant species each representing a different additional genus from these families supported another 39% of herbivore species, and the remaining 55 plant species from these genera supported 22% of herbivore species. Lepidoptera was the most speciose taxon in the local fauna, followed by Coleoptera and orthopteroids (Orthoptera and Phasmatodea). The ratio of herbivore to plant species and the estimated relative species richness of the Lepidoptera, Coleoptera, and orthopteroids remained constant on the spatial scale from 0.25 to 1 ha. However, the utility of local taxon-to-taxon species ratios for extrapolations to geographic scales requires further study.

The IBISCA approach to biodiversity assessment in forests was, initially, the brainchild of Yves Basset, Bruno Corbara and Hector Barrios (Basset et al. 2007). The four IBISCA projects carried out to date have examined selected aspects of beta-diversity in tropical, subtropical and temperate forests. In each case a set of research questions were defined and a sampling design executed. Researchers with interests in particular taxa or ecological processes were invited to join one or more of the proposed field expeditions to carry out sub-projects of their choice within the general experimental design. When successful, this approach not only provides individual researchers or groups of researchers with analyzable and publishable data sets in their specific areas of interest but it also facilitates comparative and other meta-analyses with homogeneous criteria.

Understanding how tropical rainforest trees may respond to the precipitation extremes predicted in future climate change scenarios is paramount for their conservation and management. Tree species clearly differ in drought susceptibility, suggesting that variable water transport strategies exist. Using a multi-disciplinary approach, we examined the hydraulic variability in trees in a lowland tropical rainforest in north-eastern Australia. We studied eight tree species representing broad plant functional groups (one palm and seven eudicot mature-phase, and early-successional trees). We characterised the species' hydraulic system through maximum rates of volumetric sap flow and velocities using the heat ratio method, and measured rates of tree growth and several stem, vessel, and leaf traits. Sap flow measures exhibited limited variability across species, although early-successional species and palms had high mean sap velocities relative to most mature-phase species. Stem, vessel, and leaf traits were poor predictors of sap flow measures. However, these traits exhibited different associations in multivariate analysis, revealing gradients in some traits across species and alternative hydraulic strategies in others. Trait differences across and within tree functional groups reflect variation in water transport and drought resistance strategies. These varying strategies will help in our understanding of changing species distributions under predicted drought scenarios.