Species-richness and soil phosphorus in plant communities in coastal New South Wales

Species-richness (recorded as number of species in 16 m² quadrats), in more than 60 coastal sites developed over various substrata, exhibited a significant non-linear relationship with soil total phosphorus extracted from associated soil samples. Although the general form of this relationship is not incompatible with a resource competition model, the significant proportion of the total variance accounted for by the species-richness/phosphorus relationship suggests that a more detailed examination of phosphorus use at a community level will be profitable.     

Molecular diversity of soil basidiomycete communities in northern-central New South Wales, Australia

Basidiomycete communities were profiled using terminal RFLP (TRFLP) and amplified ribosomal DNA restriction analysis (ARDRA) approaches at seven field sites under differing land use in northern-central New South Wales (NSW), Australia. TRFLP data indicated greater basidiomycete species richness at sites with natural vegetation. Sixty-seven basidiomycete ARDRA-types were detected. Various putatively ectomycorrhizal fungi were detected at all sites with native vegetation. Most ectomycorrhizal taxa had affinities to the genus Tomentella, while two Pisolithus taxa and putatively ectomycorrhizal Cantharellales taxa were also detected. Although soils under woodland or grassland communities supported a range of putatively saprotrophic taxa, only members of the Ceratobasidiales were detected in soils under agricultural land use. This study is the first investigation of fungal communities in soils of northern-central NSW, Australia.     

Responses of Bradford-reactive soil protein to experimental nitrogen addition in three forest communities in northern lower Michigan

Increased use of anthropogenically fixed N and the release of N in combustion products have led to concerns about possible long-term impacts on terrestrial ecosystems. Previous studies demonstrating the potential of atmospheric N deposition to influence forest soil carbon have focused on decomposition processes with much less known about potential impacts on mycorrhiza-derived carbon. Glomalin is a unique glycoprotein produced by arbuscular mycorrhizal (AM) fungi that has been implicated in the formation of soil aggregates and potentially a significant store of soil carbon. To determine the possible impact of experimental N deposition of such stores we examined the operationally defined glomalin-related soil protein (GRSP) levels over two growing seasons in three forest types receiving background N deposition (control) or treated with 80 kg N ha⁻¹ year⁻¹ as NaNO₃. Three sites of each of three forest types, sugar maple-basswood (SMBW), sugar maple-red oak (SMRO), and black oak-white oak (BOWO), in northern Lower Michigan were studied during the 2001 and 2002 growing seasons. GRSP were extracted from air-dried soils with citric acid and measured by the Bradford method. Analysis of variance revealed significant differences related to forest type and sample date in easily extractable Bradford reactive (EE-BRSP) and Bradford-reactive soil protein (BRSP), but failed to detect significant effects of experimental N amendment. EE-BRSP and BRSP varied in a pattern that was consistent with an AM fungal origin; a pattern that reflected the mycorrhizal types of the dominant over and understory plants of each forest ecosystem. SMBW forests dominated by AM plants had the highest levels of protein. BOWO forests with low AM plant cover had the lowest protein levels and SMRO forests were intermediate. Both Bradford-reactive fractions and their ratio varied seasonally, generally being highest in fall samples. Significant correlations observed between BRSP fractions, phosphorous, and soil organic matter were likely related to covariation of soil properties across forest types. While not statistically significant, response patterns of BRSP to N deposition were ecosystem-specific and reflected mycorrhizal types of dominant species. Abundance of these proteins reflected previously observed changes in SOC in the two forest types examined with abundant AM hosts. Specifically, nitrate addition led to BRSP decreases in SMBW and increases in SMRO forests. Changes in BRSP accounted for a small fraction of the changes in SOC; appearing to increase as a fraction of residual SOC consistent with the idea that GRSP are recalcitrant. BRSP remained unchanged at BOWO sites despite a significant increase in SOC at these sites. Our results point to the potential of proteins as contributors to differential, mycorrhizal type-specific responses to changes in soil carbon following N amendment.     

Litter production and decomposition from an overstorey of Eucalyptus spp. on two catchments in the New England region of New South Wales

Litter fall on two catchments, one with an almost continuous canopy of Eucalyptus spp., the other with a discontinuous eucalypt canopy was measured for 29 4-week periods. Annual litter accretion(2.5-3.7 t ha^?1) was low by world standards, but similar to other Australian dry sclerophyll forests. Between 33 and 54% of the total litter fall occurred during summer, and only 6-13% in winter. Leaf was the major component of litter fall and usually contributed more than 50% of the total. Variability between the 4-weekly litter falls was high, but coefficients of variation for the total annual fall were low (<5%). Half-life of total litter fall in the continuous forest (2.14 y) was double that in the discontinuous forest (0.98 y), and may have been due to differences in air temperature and surface soil moisture. The pattern of litter fall on each catchment was related to hydro-meteorological variables including air temperature, solar radiation, rainfall and soil moisture content.     

Mineralization of amino acids and its signs in nitrogen cycling of forest soil

Amino acid mineralization and its fate in soil have effects on soil nitrogen cycling. Here we used ¹⁵N-labeled alanine and methionine to study differences in their mineralization from soil organic nitrogen under 60% WHC (water holding capacity) and 90% WHC soil conditions. We found that the maximum mineralization rates were at the 24th hours for alanine and at the 5th hours for methionine, and about two times greater rates at 60% WHC than at 90% WHC. The half-live was 24–72 h for alanine and > 72 h for methionine. Half-lives of amino acids occurred sooner under 90% WHC than under 60% WHC. The results suggested that some kind of amino acids do lead the nitrogen cycling in a specific ecosystem or as a sign to trigger soil nitrogen cycling when land utilization was altered or disturbed severely by humans.     

Mineralization of biuret nitrogen in soil

Summary Study of the mineralization of biuret N under aerobic and anaerobic conditions in a sandy loam showed that higher amounts of mineral N accumulated under anaerobic incubation than under aerobic conditions. Under waterlogged incubation, 46.8% of the 100 ppm biuret N was mineralized while under aerobic conditions only 18.3% of biuret-N was converted into mineral N during 5 weeks at 30°C. The results of the study bring out slow-release nature of biuret-N.     

Mineralization of carbon and nitrogen in soil samples taken from three fertilized pine stands: Long-term effects

Seven years after fertilization the rate of CO₂ production in the soil samples taken from the organic horizons of a poor pine forest site (Calluna vulgaris site type), treated with urea or ammonium nitrate with lime, was lower than that in the unfertilized soil. The same trend was also observed in samples of theEmpetrum-Calluna site type 14 years after fertilization. In the more fertileVaccinium myrtillus site type these rapidly-soluble N fertilizers had a long-term enhancing effect on the production of CO₂. Apatite and biotite eliminated the decreasing effect of urea on the production of CO₂. One reason for this might be the long-term increase in soil pH caused by apatite and biotite, or their constituents (Ca, Mg, K, P). Nitroform (a slow-releasing N fertilizer) had no statistically significant effect on the production of CO₂ in soil samples from any of the forest types. Despite the high N mineralization in the samples from nitroform fertilized soils there was no nitrification, and the high content of total N indicated that after nitroform fertilization the losses of N were low.The correlation between the net mineralization values for C (CO₂ production) and N was poor. However, multiple linear regression analysis, which also took into account the effect of nutrients and pH, indicated that there was a link between the mineralization of C and N.     

New prosauropod material from South Wales

New prosauropod material from a cave filling of Upper Triassic/Lower Jurassic age in Pant-y-ffynnon Quarry, South Wales, is described. The Panl-y-ffynnon fauna also includes thecodont, coelurosaur, crocodile and lepidosaur material.
Most of the prosauropod skeleton is represented. An almost complete but disarticulated skull is preserved. The skull and whole skeleton of the prosauropod are reconstructed. Evidence from the size and relative proportions of the bones, also the state of ossification, indicates that the prosauropod remains represent juveniles.
The level of the jaw articulation combined with the form of the teeth would suggest that the Pant-y-ffynnon prosauropod was omnivorous.
The Pant-y-ffynnon prosauropod resembles closely the much less complete Durdham Down (Bristol) remains of Thecodonlosaurus antiquus Morris; the Welsh material could well be juveniles of that species. Here the Pant-y-ffynnon material is ascribed to Thecodonlosaurus sp.
The mode of deposition of the fossil material is discussed, to account for the deposit containing only juveniles of the prosauropod.     

Mineralization of carbon and nitrogen in acid forest soil treated with fast and slow-release nutrients

The effects of slow (apatite, biotite) and fast-release nutrients (P, K, Mg) on C and N mineralization in acid forest soil were studied. These nutrients were applied alone or together with urea or urea and limestone. The production of CO₂ in the soil samples taken one and three growing seasons after the application was lower in the soils treated with the fast-release nutrients than in the untreated soils. Similar reduction of microbial activity was not seen after the apatite and apatite+biotite treatments. In the first growing season, urea and urea+limestone enhanced CO₂ production, but after three growing seasons, the opposite was true. Apatite and apatite+biotite added together with urea did not compensate for the decreasing effect of urea on the CO₂ production. The addition of fast-release salts increased somewhat the concentration of NH _inf4 ^sup+ in the soil and more NH₄ ⁺ accumulated during laboratory incubation in the soil samples taken one growing season after the application. The urea addition immediately increased the concentrations of NH₄ ⁺ and of NO₃ ⁻ in the soil, but, three growing seasons after application, urea had only a slight increasing effect on mineral N content of the soil. Slow-release nutrients seem to have a more favourable effect than fast-release salts on nutrient turnover in acid forest soil.     

The urease activity in profiles of five great soil groups from northern New South Wales

Summary The urease activity of soil profiles under swards of improved pasture, from five great soil groups from northern New South Wales, was determined by the modified Hoffmann-Teicher method. Arbitrary sampling depths generally coincided with well differentiated horizon boundaries and comparisons on a depth basis were made among the different soil groups.In all profiles urease activity was higher in the surface soil than in deeper horizons; except in the krasnozem the fall below the surface three inches was sharp. The urease activity below 18 inches in the chocolate soil was higher than in the podzolic and red-brown earth groups. In six samples from podzolic soils containing weathering parent material or gley mottles, no urease activity was detected.The surface 0–3 inches of krasnozem soil, in four out of five profiles, had a lower urease activity than that soil immediately below. The cause of this different pattern of distribution was not determined.A highly significant correlation (r=+0.875) between urease activity and soil organic carbon indicated a moderately strong positive relationship. In the krasnozem this relationship was highly significant (r = +0.929) and in the red-brown earth and yellow podzolic soils significant correlations (r=+0.918, r=+0.777) were found. The correlation of urease activity and soil reaction for all soils was not significant.The presence of gleyed zones in the gley podzolic soil and the higher pH of the red-brown earth are discussed as other factors influencing the pattern of urease activity distribution in the soil profiles examined.     

Changes in soil macroarthropod communities in relation to forest maturation through three successional stages in the Canadian boreal forest

The edaphic macroarthropod communities of three sites representative of the forest succession in the Lake Duparquet region (situated in the southern part of the boreal forest, Abitibi, Quebec, Canada) were studied. A 47-year-old deciduous forest, a 144-year-old mixed forest, and a 231-year-old coniferous forest form a successional forest gradient with a vegetation composition that is a function of the time elapsed since the last forest fire. Along with forest succession, there is a reduction in macroarthropod community biodiversity. There is a negative gradient for mean total abundance (237–41 individuals), total richness (63–23 species), density (1792–661 individuals/m²), diversity (H′ = 1.478–1.007) and equitability (J = 0.821–0.739). These community changes affect saprophagous organisms more than predators. Certain species or taxa show preferences for a particular forest type, such as larval Diptera for the deciduous forest. A comparison of these results with the literature suggests an inverse preference as to habitat choice between microarthropods (Acarina and Collembola) and macroarthropods. From a conservation point of view, macroarthropod biodiversity will be favored by the protection of all forest types since each environment possesses a particular community structure and species. Received: 17 April 1995 / Accepted: 1 April 1996     

An altitudinal transect in rain forest in the Barrington Tops area,New South Wales

On the southern slopes of Barrington Tops, N.S.W., an exploratory study was made of altitudinal gradation between subantarctic or temperate rain forest (at higher elevations) and subtropical rain forest. The former is dominated by Nothofagus moorei while the latter has no clear dominants and is floristically and structurally more complex. To sample the ecotone, a single 800 m line containing thirty-seven 200 m² circular plots was placed on a S.S.W.-facing slope between altitudes of 800 and 1040 m. The inclinations of the surfaces of individual plots ranged from 5° to 35°. Measurement and analysis were restricted to trees (including coppices), vines and tree ferns, with emphasis on density, basal area and importance values. Vertical extent of the ecotone is determined rather arbitrarily as being about 90 m. Floristically, the ecotone has elements both of a mosaic and of a gradual mix of species of the upper and lower rain forests. Its areal complexity is increased by the presence of small-scale topographic features; the typical step-and-terrace sequence resulting from dissection of multiple basalt flows. There is a gradual dropping out of species of the subtropical rain forest upwards along the whole transect. The rate of drop-out is greatest at the bases of any steep steps on the slope. Certain species, notably Doryphora sassafras, are shared by the two kinds of rain forest. In physiognomy too, there is further evidence for continuity: the size and density of vines as well as leaf sizes of trees and vines decrease gradually upwards. In terms of Webb's system of structural types of Australian rain forest there is sustained gradation from notophyll-microphyll vinefern forest (at the bottom) to microphyll fern forest. There is strong evidence that Nothofagus moorei is not regenerating within most of the ecotone. Speculation is offered about ecotonal dynamics in terms of climatic change, fire frequency and the mode of reproduction of N. moorei.     

The marine macrobenthic communities of Wallis and Smiths Lakes,New South Wales

The shallow macrobenthic communities of Wallis and Smiths Lakes on the central N.S. W. coast have been studied by replicate grab samples. Wallis Lake is a coastal marine lagoon constantly open to the sea, whereas Smiths Lake, also a coastal lagoon, is periodically closed to the sea for several months at a time. The benthic communities were described using indices of dominance and diversity. Between site communities were compared using MULTBET and a GOWER ordination. Generally, sites in Wallis Lake had a more diverse fauna than those in Smiths Lake. Weed beds supported more species and individuals than sandy substrates. The benthic fauna of these two lakes is compared with other coastal rivers and lagoons which have been studied in temperate eastern Australia.     

A fossil Selaginella from the Permian of New South Wales

Selaginella harrisiana ap. nov. is described from the Permian (Kungurian) Upper Coal Measures at Victoria Pass, N.S.W. It resembles Selaginella selaginoides in its leafy parts but has a long leafless rhizome recalling Asteroxylon. The present evidence suggests that the herbaceous and arborescent ly copsids are taxonomically remote.     

Infaunal communities and tiering in Early Palaeozoic nearshore clastic environments: trace-fossil evidence from the Cambro-Ordovician of New South Wales

Understanding of the palaeoecology of Early Palaeozoic shallow-marine communities in sandy habitats is incomplete. Reasons for this include the poor preservation of body fossils and the dominance of Skolithos piperock in sandstones of that age. Cambrian and Ordovician deposits preserving diverse nearshore trace-fossil assemblages are therefore of critical importance for assessing the early evolution of marine ecosystems. The basal part of the Cambro-Ordovician Bynguano Formation of the Mootwingee area (New South Wales, Australia) is a series of interbedded sandstones and mudstones, which were deposited under nearshore conditions. These strata provide an early example of the Arenicolites ichnofacies. Two ichnocoenoses are distinguished in the sandstones of this unit. A 'predepositional' ichnocoenosis, which reflects the benthic community prior to episodes of sand deposition, includes dense aggregations of Rusophycus with rare Planolites. The 'postdepositional' ichnocoenosis is more diverse and includes Thalassinoides, Arenicolites (various types), Monocraterion, Skolithos, Trichichnus , and epichnial grooves. The tiered structure developed in this ichnocoenosis is preserved as a 'frozen tiered profile' and is characterised by a Thalassinoides tier, 10–30 cm in depth, which is cross-cut by Skolithos and Arenicolitesin the middle tier, and by Arenicolites and Trichichnusin the shallowest tier. The pattern of tiering indicates that a complex ecosystem of opportunistic organisms, capable of exploiting shifting substrates, had evolved by the earliest Ordovician. □ Predepositional, postdepositional frozen tier profile, ichnocoenosis, nearshore clastics, RUSOPHYCUS, Cambro-Ordovician, Bynguano Formation, Mootwingee, New South Wales.     

Historical perspectives on some vegetation and soil changes in semi-arid New South Wales

The history of settlement of the semi-arid rangelands of western New South Wales is reviewed with respect to changes in the vegetation and soil which occurred under a regime of european land management. Simple dynamics of the vegetation response to grazing are illustrated and primary archival data is explored to verify the status of traditional wisdom about three examples of perceived change; the extent of the pioneers knowledge of land degradation, the timing and causes of nineteenth century Callitris pine regrowth events, and the importance of soil compaction. In each case it is shown that the traditional wisdom surrounding these issues is partly erroneous and that folklore is in danger of becoming accepted fact. Such errors must be avoided if we are to improve range dynamics models and management.