Patterns in north Queensland mangrove vegetation

This note suggests an additional interpretation of analyses of north Queensland tidal forest vegetation recently presented by Bunt & Williams (1980a). They separated 30 species associations defined by various combinations of 11 defining species, and showed that these associations do not form a single invariant zonal sequence, as implied previously by Macnae (1966). Their results do indicate, however, that individual mangrove species are characteristically associated with different sections of the overall tidal range. This does not contradict their conclusions but rather places a different emphasis on their results.     

The importance of Quaternary records in reducing risk from tropical cyclones

Numerous late Holocene records of tropical cyclones have been collected from north-east Queensland, Australia. They are in the form of multiple sedimentary ridges paralleling the shore. The ridges are composed of coral fragments, or shell and sand or pure sand. A method to determine the intensity of the tropical cyclone responsible for deposition of the ridges at each site has been applied and the results suggest that in the majority of cases these features were deposited by very high magnitude events. The results suggest that extrapolations of long-term cyclone magnitude and frequencies from the 30- to 40-year-long instrumental record, which is the method commonly used to assess risk from this hazard, substantially underestimate the risk from this hazard. This is confirmed for the Cairns region by an 800-year-long high-resolution isotope record of tropical cyclones preserved in a limestone stalagmite. Together the sedimentary and isotope records suggest that tropical cyclone activity in north-east Queensland has been in a phase of quiescence since before European settlement of the region in approximately AD 1870. It is suggested that the incorporation of the palaeo record into risk assessments will provide a more realistic guide to the magnitude frequency relationship of tropical cyclones and help reduce risk from this hazard as a consequence.     

Soil and litter respiration in rainforests of contrasting nutrient status and physiognomic structure near Lake Eacham,north-east Queensland

Soil and litter respiration and nutrient concentrations (N, P, Ca, Mg and K) were measured in two adjacent rainforests near Lake Eacham on the Atherton Tableland in north-east Queensland. One forest had soil formed on basalt and, in physiognomic-structural classification of Webb (1968, 1978), was structurally complex. The other had soil formed on metamorphic rock and was structurally simple. Respiration was measured by the alkali trap method on 16 monthly occasions in 1986 and 1987. Soil and litter nutrient concentrations were higher in the complex forest (with the exception of soil N). The relative differences were greater for soil than litter and more pronounced for P and Ca (and also soil Mg) than other nutrients. Litter polyphenol concentrations were lower in the complex forest. Rates of litter respiration in the complex forest were, on average, nearly twice those of the simple forest. Soil respiration rates were occasionally slightly lower in the complex forest during the wet season but did not differ between the forests during the dry season. Highest rates of respiration were measured during the wet season although high rates for litter occasionally occurred during the dry season. Cumulative CO₂ release from the soil and overlying litter did not differ between forests and averaged 5134 ± 96 g CO₂ m^-2 per year (mean ± s.e.m.) (1400 g C m^-2 per year). Litter respiration accounted for 14% of the annual release in the complex forest and 11% in the simple forest. The association between site nutrient status and forest physiognomic structure at Lake Eacham represents a more general pattern in rainforests of north-east Queensland. Further study is needed to ascertain whether the results from this study apply more generally in both primary and secondary rainforests.     

Palynology of a Holocene marine transgressive sequence,lower Mulgrave River valley,north-east Queensland

A sediment core from the lower Mulgrave River flood plain in north-east Queensland was examined using standard pollen analysis techniques to investigate vegetation and sea level changes during and since the Holocene marine transgression. Saltwater penetrated the Mulgrave River to the core site in the early Holocene, with the consequent development of riverside mangrove forests dominated by Sonneratia lanceolata, a community not previously recorded in Australian pollen sequences. From about 7000 to 6000 years ago, Rhizophora forest was the dominant vegetation community around the site. During this period, vertical sedimentation kept pace with, or at times exceeded, the rate of sea level rise. As sea level stabilized, about 6000 years ago, continued sediment accumulation led to the development of upper-intertidal Ceriops/Bruguiera forest and then freshwater swamp forest. The vegetation changes in this latter part of the sequence reflect the present seaward to landward vegetation zonation in the area.     

Long‐term effects of vegetational restoration on soil microbial communities on the Loess Plateau of China

Soil microbial communities are important indicators for evaluating the effectiveness of vegetational restoration. The ability of soil microbial communities to recover under six types of restoration was examined using Biolog, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE). Soil samples were collected from eroded loessial soils that had been restored for 30 years on the Loess Plateau with natural grass, black locust, korshinsk peashrub, Chinese pine, and mixed forest of Chinese pine‐indigo and black locust‐indigo. Part of sloped farmland that had not been restored represented pre‐restoration conditions. An 80‐year‐old forest of Chinese arborvitae represented the end point of restoration. Soils that were originally farmed but have been under restoration treatments for the past 30 years had significantly higher average well‐color development, total PLFAs, bacterial PLFAs, fungal PLFAs, and Shannon indices of catabolic diversity, structural diversity, and bacterial phylogenetic diversity. These indicators, though, were lower than those for the native forest. Principal component analysis significantly separated the sloped farmland, Chinese arborvitae, and the six types of restoration. Redundancy analysis indicated that pH, total organic carbon, total nitrogen, available nitrogen, and available phosphorus were the most important environment factors in affecting soil functional diversity, and C/N ratio and available nutrients were the main properties in determining microbial community structure. Vegetational restoration substantially increased microbial biomass and microbial physiological activity, and shifted microbial community structure, but the community structures and compositions did not recover to the status of the natural forest during the early stage (<30 years) of vegetational restoration.     

Ecological restoration of a severely degraded coastal acid sulfate soil: A case study of the East Trinity wetland,Queensland

A severely degraded acid sulfate soil wetland near Cairns, Queensland, has been returned to a functional estuarine habitat using a cost‐effective, low‐technology method based on the reintroduction of tidal water. Gradual increases in tidal inundation, combined with targeted liming of the tidal stream, restored conditions that promoted chemical and microbial processes leading to the rapid recolonisation of mangrove communities and other estuarine flora and fauna. Protocols and understanding developed at East Trinity can be readily applied to other coastal acid sulfate soil sites.     

Glacial and interglacial refugia within a long-term rainforest refugium: The Wet Tropics Bioregion of NE Queensland, Australia

An artificial neural network is used to classify environments, including climate, terrain and soil variables, according to their suitability for fifteen structural/environmental forest classes in the Wet Tropics Bioregion of north-east Queensland. We map the environments characteristic of these forest classes in four climate regimes (the present and three past climate scenarios), quantify the changes in area of these environments in response to past regional changes in climate and identify areas that would have been environmentally suitable for rainforests at last glacial maximum (glacial refugia). We also identify areas that would have been suitable for upland and highland rainforest classes during the warmest parts of the interglacial (interglacial refugia) and map locations that consistently remain favourable to specific forest classes despite large changes in climate.In the climate of the last glacial maximum (LGM), rainforest environments are predicted in three relatively distinct refugia in the northern, central and southern Wet Tropics. Only three percent of the total area contains lowland, Mesophyll Vine Forest and the majority of the area of the rainforest refugia supports upland rainforest classes. In the cool, wet climate of the Pleistocene/Holocene transition (PHT), rainforest environments expand to form a more or less continuous block from the northern limits of the region to the Walter Hill Range, except for discontinuous patches extending through the Seaview and Paluma Ranges in the south. During the Holocene climatic optimum (HCO), rainforest environments become more fragmented, especially in the south. Lowland rainforest environments are very extensive in this climate while upland rainforest classes are restricted to what we term “interglacial refugia”.Estimated distributions and stable locations (consistently predicted in all four climate scenarios) for the various rainforest environment classes are our main, novel contribution. Each forest environment responds individualistically to climate change. Our results confirm the highly dynamic nature of the Wet Tropics landscape and present a much more detailed picture of landscape change since the late Pleistocene than previously has been available. This mapping exercise should be useful in the future for analyses of present-day biogeographic patterns. We argue that empirical modelling approaches have an important role in palaeoecology and global change research that is complementary to the developing mechanistic methods.     

Pollen analyses from south-east Scotland

Summary

Features of the vegetational history in a part of south-east Scotland are interpreted from three pollen diagrams from upland sites, two of which illustrate the whole Post-glacial from Zone IV to Zone VIII. Zones and Sub-zones of the Boreal forest development are identifiable and have been indicated. Evidence of agricultural activities of early man appear in sub-zone VIIb and the effect of these and of later clearances upon the primaeval forest are interpreted from the diagrams.     

梵净山黔周林的结构和动态

(一)黔椆(Cyclobalanopsis stewardiana)林主要分布于梵净山上部回香坪以上,剪刀峡及三王殿一牛尾河一带。它是贵州省所特有的群落类型。对梵净山海拔较高地区的常绿阔叶林一一黔椆林的结构和动态的分析表明,黔椆处于一种稳定的状态中,并保持着一种相对稳定的种的组成和结构。大量的幼苗和强有力的根出条的更新方式,使黔椆在群落中保持其优势地位,从而使黔椆林成为这一地区的“顶极植物群落”。(二)黔椆在海拔1150米开始出现;在1400一1700米一带成为常绿、落叶阔叶混交林内常绿树中的优势种;在1800—2100米,黔椆优势群落成为“顶极植物群落”,以及黔椆林下存在着大量的、仅在山体上部才有分布的大箭竹,说明黔椆林是对于这一高度地带的天然生境长期适应的结果。(三)在黔椆林中的大箭竹周期性成批枯死,这可能有利于黔椆的更新,因为黔椆树苗只能生长在林冠间隙的竹杆中间。大箭竹在黔椆林中大量相继枯死,这对于树的更新十分重要。     

太白山表土花粉和气孔器与植物类型的关系研究

通过陕西太白山13个样点表土花粉组合特征和气孔器及其与植物类型之间关系的分析,结果发现:针阔混交林花粉组合能很好地反映植物类型特征,落叶阔叶林和针叶林花粉组合能较好地与植物类型相对应,高山灌丛草甸花粉组合未能反映植物类型数量特征;主要花粉类型松属、铁杉属和桦属花粉具超代表性,胡桃属和榆属花粉具适宜代表性,落叶松属、冷杉属、杜鹃花科和槭属花粉具低代表性;DCA(Detrended Correspondence Analysis)分析表明,通过花粉数据能够较好区分不同植被类型,结合气孔器特征能够准确反映植被特征。     

Climatic controls of vegetation vigor in four contrasting forest types of India—evaluation from National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer datasets (1990–2000)

Ten-day advanced very high resolution radiometer images from 1990 to 2000 were used to examine spatial patterns in the normalized difference vegetation index (NDVI) and their relationships with climatic variables for four contrasting forest types in India. The NDVI signal has been extracted from homogeneous vegetation patches and has been found to be distinct for deciduous and evergreen forest types, although the mixed-deciduous signal was close to the deciduous ones. To examine the decadal response of the satellite-measured vegetation phenology to climate variability, seven different NDVI metrics were calculated using the 11-year NDVI data. Results suggested strong spatial variability in forest NDVI metrics. Among the forest types studied, wet evergreen forests of north-east India had highest mean NDVI (0.692) followed by evergreen forests of the Western Ghats (0.529), mixed deciduous forests (0.519) and finally dry deciduous forests (0.421). The sum of NDVI (SNDVI) and the time-integrated NDVI followed a similar pattern, although the values for mixed deciduous forests were closer to those for evergreen forests of the Western Ghats. Dry deciduous forests had higher values of inter-annual range (RNDVI) and low mean NDVI, also coinciding with a high SD and thus a high coefficient of variation (CV) in NDVI (CVNDVI). SNDVI has been found to be high for wet evergreen forests of north-east India, followed by evergreen forests of the Western Ghats, mixed deciduous forests and dry deciduous forests. Further, the maximum NDVI values of wet evergreen forests of north-east India (0.624) coincided with relatively high annual total precipitation (2,238.9 mm). The time lags had a strong influence in the correlation coefficients between annual total rainfall and NDVI. The correlation coefficients were found to be comparatively high (R²=0.635) for dry deciduous forests than for evergreen forests and mixed deciduous forests, when the precipitation data with a lag of 30 days was correlated against NDVI. Using multiple regression approach models were developed for individual forest types using 16 different climatic indices. A high proportion of the temporal variance (>90%) has been accounted for by three of the precipitation parameters (maximum precipitation, precipitation of the wettest quarter and driest quarter) and two of the temperature parameters (annual mean temperature and temperature of the coldest quarter) for mixed deciduous forests. Similarly, in the case of deciduous forests, four precipitation parameters and three temperature parameters explained nearly 83.6% of the variance. These results suggest differences in the relationship between NDVI and climatic variables based upon the time of growing season, time interval and climatic indices over which they were summed. These results have implications for forest cover mapping and monitoring in tropical regions of India.     

Study of changes in life zone distribution in north-east China by climate–vegetation classification

Life zones and their changes in distribution in north-east China were studied based on climate–vegetation relationships. The warmth index (WI) and aridity index (the ratio of evaporation [evaporation rate, ER] to precipitation) were used to represent the site condition. The typical site condition of each vegetation type was determined as the classification criterion. The boundaries of the four potential vegetation zones were estimated based on the combinations of WI and ER in relation to vegetation (i.e. cold-temperate conifer forest zone, temperate broad-leaved conifer mixed forest zone, warm-temperate deciduous forest zone, and temperate steppe zone). The distribution changes in vegetation zone caused by human activities were estimated by comparing the potential vegetation with the actual one. The percentage cover of forest has shrunk from about 70% to the present 27%. About 23% of the study area was replaced by agricultural vegetation and industrial use. Nearly half of the region could have been covered by broad-leaved conifer mixed forest which was shrunk to a small area, less than 5% of the region. The broad-leaved deciduous forest zone in the southern part could have occupied about 7% of the area, and had almost no virgin stand.     

The impact of water buffalo on the monsoon forest ecosystem in Kakadu National Park

The intensity of use of forested country in the Kakadu National Park area by feral Asiatic water buffalo can be largely predicted from the area of river floodplain in the vicinity of the site, and tree canopy cover on the site. Thus some areas of monsoon forest appear to have sustained intensive use by buffalo for over a century whereas other areas have probably been little used. With sites exhibiting little buffalo use, mean DBH of trees increased with foliage height diversity (FHD). However, the sites more intensively used by buffalo had a lower canopy and did not exhibit any increase in mean DBH with a pronounced increase in FHD. Other vegetational relationships displayed by the two groups of sites are discussed. Comparison of the monsoon forest sites suggests that compaction of soil by buffalo has caused the death of large trees due to poor recharge of groundwater. The two groups of monsoon forest sites exhibited a wide variety of faunal relationships with FHD. Some species appear to be favoured while others are disadvantaged to various degrees by the habitat changes caused by the buffalo. The most intensively used site appears to have exceeded a threshold in that a number of faunal trends were reversed on that site. The impact of buffalo on some monsoon forest sites is much more fundamental than anticipated. But other sites which appear to be naturally protected by their location have experienced much less change due to buffalo.     

Fire weather risk differs across rain forest—savanna boundaries in the humid tropics of north‐eastern Australia

Alternative stable state theory has been applied to understanding the control by landscape fire activity of pyrophobic tropical rain forest and pyrophytic eucalypt savanna boundaries, which are often separated by tall eucalypt forests. We evaluate the microclimate of three vegetation types across an elevational gradient and their relative fire risk as measured by McArthur's Forest Fire Danger Index (FFDI). Microclimatic data were collected from rain forest, tall eucalypt forest and savanna sites on eight vegetation boundaries throughout the humid tropics in north Queensland over a 3‐year period and were compared with data from a nearby meteorological station. There was a clear annual pattern in daily FFDI with highest values in the austral winter dry season and lowest values in the austral summer wet season. There was a strong association of the meteorological station FFDI values with those from the three vegetation types, albeit they were substantially lower. The rank order of FFDI values among the vegetation types decreased from savanna, tall eucalypt forest, then rain forest, a pattern that was consistent across each transect. Only very rarely would rain forest be flammable, despite being adjacent to highly flammable savannas. These results demonstrate the very strong effect of vegetation type on microclimate and fire risk, compared with the weak effect of elevation, consistent with a fire–vegetation feedback. This study is the first demonstration of how vegetation type influences microclimate and fire risk across a topographically complex tropical forest–savanna gradient.     

Recent successional processes investigated by pollen analysis of closedcanopy forest sites

Forest succession was investigated by pollen analysis of two mor-humus sections and of peat from a 3 m-diameter hollow under mixed conifer-hardwood forest in north-central Massachusetts, USA. The humus profiles recorded a major forest perturbation caused by the removal of Castanea dentata by the chestnut blight (1910–1912), and the peat from the hollow extended the record beyond the time of colonial settlement (1733). Fagus grandifolia was a forest dominant before 1733 but declined abruptly upon settlement. Castanea, a late Holocene immigrant to the area, rapidly increased its pollen representation after settlement until the epidemic of the chestnut blight. Forest succession following the loss of Castanea involved the successive rise to dominance of Betula, Quercus, Acer rubrum, and Tsuga canadensis. These vegetational changes conform to observations made during studies of forest-stand composition by other workers. Allogenic factors such as logging, disease, and wind have initiated major compositional change, which has been modified by autogenic successional processes such as the gradual rise to dominance of Tsuga canadensis around one of the humus sections. The two humus sites resolve fine-scale pattern in former vegetation such as differences in the distribution of Pinus strobus and Castanea over 200 m, the distance between the mor-humus sites. These within-forest sites permit investigations of fine-scale vegetational patterns and processes that are of interest to forest ecologists.     

Observations on the utilisation of a restored wildlife corridor by echo-locating microbats in North Queensland's Wet Tropics

Microbat studies are uncommon in the Wet Tropics of north-east Queensland, despite the group comprising 20% of the bioregion's mammal fauna. The significance of fragmentation and habitat connectivity to the echolocating insectivore group is unknown. Over a 12-month period in 2021–2022, microbat presence was recorded in a 25-year-old restored wildlife corridor 1.2 km in length. We deployed Anabat detectors in the restored corridor, in adjacent open paddocks and in mature rainforest at either end of the corridor. Species in reference forest and corridor vegetation were consistently ‘clutter-adapted’ bats, with low aspect ratio wings; there was little overlap with high aspect ratio species of the open pasture. Low aspect ratio microbats appear to respond to the similarity in structure between restored and adjacent natural vegetation. Re-establishing structural and functional connectivity may improve the local persistence of ‘clutter-adapted’ microbats.     

The Phytocoenological Features of Evergreen Broad-Leaf Forest in Guangxi

The evergreen broad-leaf forest is a zonal vegetational type of humid subtropics. Analysis of its phytocoenological features realizes that, its physiognomy is characteri, Zed by the leathery simple-leaved mesophyllons and microphyllous type of phaneno. phytes. In the structure of community, there is more distinct stratification, synusia Structure is considerably complex, each layer has distinct dominant synusium. The floristie composition is dominated by endemic Chinese subtropical plant species and Eastasian elements, this condition indicates that it should be considered as special vegetational type of humid Chinese subtropics. From the viewpoint of succession, it is the relative stable community type suited with local enviroment. At present, the area of such forest is not large, it must strengthen the protection. Selective cutting system where only the mature individual tree, are harvested at different intervals better. Many economic plants in the forest are worth introduction and cultivation carrying out multistoried management.     

North—South Patterns within Arboreal Ant Assemblages from Rain Forests in Eastern Australia1

This paper describes the ant assemblages sampled from rain forest canopies ranging from southern Victoria through to Cape York Peninsula, Australia, and also in Brunei. Specifically, it examines the influence of decreasing latitude and variations in elevation on the character, richness, and abundance of the arboreal rain forest ant fauna, and also the relative contribution of ants to the total arthropod community. The sites that were examined included: cool temperate Nothofagus cunninghamii forest from a range of locations in Victoria; cool temperate N. moorei forest at both Werrikimbe and Styx River, New South Wales; notophyll vine forest in Lamington National Park, southeast Queensland; high elevation notophyll vine forest in Eungella National Park, central Queensland; complex notophyll vine forest at Robson Creek, Atherton Tablelands, north Queensland; complex mesophyll vine forest at Cape Tribulation, north Queensland; and mixed dipterocarp forest in Brunei. Although these sites represent a gradient increasingly tropical in character, botanically speaking, Eungella is less tropical than Lamington because of its high elevation. All samples were obtained by fogging the canopy with a rapid‐knockdown pyrethrin pesticide. In all cases, circular funnels were suspended beneath the foliage of individual trees or small plots of mixed canopy. Arthropods were collected four hours after fogging. Following ordinal sorting, ants were identified and counted to morphospecies level. The resulting catch were then standardized across sites as numbers caught per 0.5 m² sampling funnel. Generic and species richness were higher at the lowland tropical Cape Tribulation sites than at the sites to the south and was comparable with values in the Brunei site. Species richness was negatively correlated with latitude and elevation. Within the Australian rain forest, the lowland/highland break appears to be the strongest predictor of ant relative abundance, with a weaker latitudinal relationship superimposed.     

Near‐ground solar radiation along the grassland–forest continuum: Tall‐tree canopy architecture imposes only muted trends and heterogeneity

Solar radiation directly and indirectly drives a variety of ecosystem processes. Our aim was to evaluate how tree canopy architecture affects near‐ground, incoming solar radiation along gradients of increasing tree cover, referred to as the grassland–forest continuum. We evaluated a common type of canopy architecture: tall trees that generally have their lowest level of foliage high above, rather than close to the ground as is often the case for shorter trees. We used hemispherical photographs to estimate near‐ground solar radiation using the metric of Direct Site Factor (DSF) on four sites in north Queensland, Australia that formed a grassland–forest continuum with tree canopy cover ranging from 0% to 71%. Three of the four sites had tall Eucalyptus trees with foliage several metres above the ground. We found that: (i) mean DSF exceeded >70% of the potential maximum for all sites, including the site with highest canopy cover; (ii) DSF variance was not highly sensitive to canopy coverage; and (iii) mean DSF for canopy locations beneath trees was not significantly lower than for adjacent intercanopy locations. Simulations that hypothetically placed Australian sites with tall tree canopies at other latitude–longitude locations demonstrated that differences in DSF were mostly due to canopy architecture, not specific site location effects. Our findings suggest that tall trees that have their lowest foliage many metres above the ground and have lower foliar density only weakly affect patterns of near‐ground solar radiation along the grassland–forest continuum. This markedly contrasts with the strong effect that shorter trees with foliage near the ground have on near‐ground solar radiation patterns along the continuum. This consequence of differential tree canopy architecture will fundamentally affect other ecosystem properties and may explain differential emphases that have been placed on canopy–intercanopy heterogeneity in diverse global ecosystem types that lie within the grassland–forest continuum.     

Anthropogenic hive movements are changing the genetic structure of a stingless bee (<Emphasis Type="Italic">Tetragonula carbonaria</Emphasis>) population along the east coast of Australia

Across the world, the keeping of stingless bees is increasingly popular, providing commercial pollination, high-value honey and a rewarding pass time. The popularity of stingless beekeeping has resulted in large-scale anthropogenic movements of nests, sometimes from outside their native range. Colony movement has the potential to impact local populations via transfer of parasites and pathogens and gene flow across unnaturally large geographic scales. Tetragonula carbonaria is the most widespread and commonly kept stingless bee species in Australia. Concerns have been raised that large-scale artificial propagation of T. carbonaria colonies by Sydney beekeepers, from a small number of colonies that originated in south-east Queensland, may have two consequences. First, the managed population may be becoming increasingly inbred. Second, the wild population may be experiencing significant introgression of south-east Queensland genotypes, potentially diluting local adaptations to the Sydney environment and resulting in the loss of local alleles. Here we show, based on microsatellite and mitochondrial markers, that both the managed and wild Sydney populations are significantly different from the south-east Queensland population. Nonetheless there is evidence that introgression of south-east Queensland alleles is impacting the genetic structure of both wild and managed Sydney populations. The two Sydney populations are indistinguishable, suggesting two-way gene flow in Sydney consistent with expectations of gene flow via male dispersal. All populations have low inbreeding coefficients, suggesting that they are genetically healthy.