Turbulence structure of a tropical forest

A detailed analysis is presented of the horizontal wind fluctuations with periods 20 s to 1 hr, and their vertical structure as measured with light three-cup anemometers in a tropical forest environment. Information collected during the TREND (Tropical Environmental Data) experiment in a monsoon dominated region, was utilized. A special attempt was made to extract information relevant for dispersion modeling. Variability parameters within and above the forest canopy under different stability conditions were derived. A similar analysis was performed for a nearby clearing, to facilitate comparison between relatively smooth and rough surfaces, under identical ambient conditions. A limited sample of data (7 days) was utilized, initially, to develop a methodology to be later applied on a comprehensive data base, spanning the whole monsoon cycle.     

A calculated petrogenetic grid for ultramafic rocks in the system CaO-FeO-MgO-Al2O3-SiO2-CO2-H2O at low pressures

Calculated phase equilibria among the minerals amphibole, chlorite, clinopyroxene, orthopyroxene, olivine, dolomite, magnesite, serpentine, brucite, calcite, quartz and fluid are presented for the system CaO–FeO–MgO–Al₂O₃–SiO₂–CO₂–H₂O (CaF-MASCH), with chlorite and H₂O–CO₂ fluid in excess and for a temperature range of 440°C–600°C and low pressures. The minerals chosen in CaFMASCH represent the great majority of phases encountered in metamorphosed ultramafic rocks. The changes in mineral compositions in terms of FeMg_-1 and (Mg, Fe)SiAl_-1Al_-1 are related to variations in the intensive parameters. For example, equilibria at high in the presence of chlorite involve minerals which are relatively aluminous compared with those at low . The calculated invariant, univariant and divariant equilibria are compared with naturally-occurring greenschist and amphibolite facies ultramafic mineral assemblages. The correspondence of sequences of mineral assemblages and the compositions of the minerals in the assemblages is very good.     

Fate of individual sewage disposal system wastewater within regolith in mountainous terrain

In order to improve understanding of the fate of septic tank or individual sewage disposal system (ISDS) effluent in regolith overlying fractured-rock aquifers, effluent from an ISDS in such a setting was tracked via geophysical, hydrological, and geochemical methods. Under typical precipitation conditions, the effluent entered the fractured bedrock within 5 m of the boundary of the constructed infiltration area. During a period of unusually high spring recharge, the plume migrated between 50 and 100 m within the regolith before infiltrating the fractured bedrock. The chemical signature of the effluent is similar to that required to account for the decline in water quality, suggesting a causative relationship (as estimated from mass-balance models of the surface-water chemistry near the mouth of the basin). The elevated salt content of the effluent during periods of high natural recharge to the infiltration area correlates with elevated salt concentrations in surface and groundwater at the basin scale, suggesting that some of the effluent salt load may be stored in the unsaturated zone during dry periods and flushed during periods of elevated natural recharge.     

The Digital National Framework and Digital Photogrammetry at Ordnance Survey

Over recent months the Ordnance Survey, Britain's national mapping agency, has changed the way in which it uses photogrammetry to update its large scales topographic database. The nature of the database itself has also changed during the same period, as the concept of a "Digital National Framework" has developed. This paper describes the Digital National Framework, the topographic data captured by Ordnance Survey within this framework and the capture methods currently used. The paper concentrates on the use of photogrammetry in the update process, describing the methods of the past, the methods currently in production, and the outlook for photogrammetry within the Ordnance Survey in future.     

Reconstructing nutrient histories in the Norfolk Broads, UK: implications for the role of diatom-total phosphorus transfer functions in shallow lake management

The fossil diatom records preserved in radiometrically dated sediment cores from four shallow lakes in the Norfolk Broads, UK (Barton Broad, Rollesby Broad, Wroxham Broad and Upton Broad) were analysed. A weighted-averaging partial least squares (WA-PLS) diatom-total phosphorus (TP) transfer function, based on a training set of 152 mostly shallow (maximum depth < 3 m) lakes in northwest Europe, was applied to the full diatom dataset for each core to reconstruct the past TP concentrations of the lakes. Owing to the dominance of non-planktonic Staurosira, Pseudostaurosira and Staurosirella spp. (formerly classified in the genus Fragilaria) throughout the diatom records, the quantitative diatom inferred TP (DI-TP) concentrations did not adequately reflect the changes that occurred in the lakes as indicated by shifts in the other diatom taxa, or as reported in the literature. This was most apparent at Barton Broad and Rollesby Broad, where there was a marked increase in the importance of planktonic taxa associated with highly nutrient-rich waters but no increase in DI-TP. The modern and fossil data were thus square-root transformed to downweight the dominant taxa and the new transfer function was applied to the cores. An improvement was seen only in the reconstruction for Barton Broad. Finally, the Staurosira, Pseudostaurosira and Staurosirella spp. were removed from the modern and fossil diatom data, and the transfer function was re-applied. The trends in DI-TP became less clear, particularly for Upton Broad and Barton Broad, owing to a paucity of data for calibration once these taxa were deleted from the counts data. The problems associated with reconstructing trophic status and determining TP targets for restoration from fossil diatom assemblages in these systems are discussed.     

Common cause or common concern? The role of common lands in the post-productivist countryside

Summary The aim of this paper is to contribute towards a better understanding of the contemporary position of commons as a land resource, and to evaluate whether commons have a distinct role to play in today's 'post-productivist' countryside. Following the government's recent recognition of the multi-functional role of commons, the paper sets out to investigate whether this can be achieved through existing agri-environmental schemes. A case study of commons in the Cambrian Mountains (Wales) enables an assessment of the compatibility of one recent agri-environmental scheme, the ESA scheme, with commons management. It is concluded that new legislation and policy are needed, and that agri-environmental policy may provide an opportunity to develop a framework within which the management of common land can be improved to meet conservation and amenity as well as farming objectives.     

A global model of changing N2O emissions from natural and perturbed soils

A high resolution global model of the terrestrial biosphere is developed to estimate changes in nitrous oxide (N₂O) emissions from 1860–1990. The model is driven by four anthropogenic perturbations, including land use change and nitrogen inputs from fertilizer, livestock manure, and atmospheric deposition of fossil fuel NO _x . Global soil nitrogen mineralization, volatilization, and leaching fluxes are estimated by the model and converted to N₂O emissions based on broad assumptions about their associated N₂O yields. From 1860–1990, global N₂O emissions associated with soil nitrogen mineralization are estimated to have decreased slightly from 5.9 to 5.7 Tg N/yr, due mainly to land clearing, while N₂O emissions associated with volatilization and leaching of excess mineral nitrogen are estimated to have increased sharply from 0.45 to 3.3 Tg N/yr, due to all four anthropogenic perturbations. Taking into account the impact of each perturbation on soil nitrogen mineralization and on volatilization and leaching of excess mineral nitrogen, global 1990 N₂O emissions of 1.4, 0.7, 0.4 and 0.08 Tg N/yr are attributed to fertilizer, livestock manure, land clearing and atmospheric deposition of fossil fuel NO _x , respectively. Consideration of both the short and long-term fates of fertilizer nitrogen indicates that the N₂O/fertilizer-N yield may be 2% or more.C. NBM Definitions AET _mon (cm H₂O) = monthly actual evapotranspiration - AET _ann (cm H₂O) = annual actual evapotranspiration - age _h (years) = stand age of herbaceous biomass - age _w (years) = stand age of woody biomass - atmblc (gC/m²/month) = net flux of CO₂ from grid - biotoc (gC/g biomass) = 0.50 = convert g biomass to g C - beff _h = 0.8 = fraction of cleared herbaceous litter that is burned - beff _w = 0.4 = fraction of cleared woody litter that is burned - bfmin = 0.5 = fraction of burned N litter that is mineralized or converted to reactive gases which rapidly redeposit. Remainder assumed pyrodenitrified to N₂. + N₂O - bprob = probability that burned litter will be burned - burn _h (gC/m²/month) = herbaceous litter burned after land clearing - burn _w (gC/m²/month) = woody litter burned after land clearing - cbiomsh (gC/m²) = C herbaceous biomass pool - cbiomsw (gC/m²) = C woody biomass pool - clear (gC/m²/month) = woody litter C removed by land clearing - clearn (gN/m²/month) = woody litter N removed by land clearing - cldh (month^–1) = herbaceous litter decomposition coefficient - cldw (month^–1) = woody litter decomposition coefficient - clittrh (gC/m²) = C herbaceous litter pool - clittrw (gC/m²) = C woody litter pool - clph (month^–1) = herbaceous litter production coefficient - clpw (month^–1) = woody litter production coefficient - cnrath (gC/gN) = C/N ratio in herbaceous phytomass - cnrats (gC/gN) = C/N ratio in soil organic matter - cnratt (gC/gN) = average C/N ratio in total phytomass - cnratw (gC/gN) = C/N ratio in woody phytomass - crod (month^–1) = forest clearing coefficient - csocd (month^–1) = actual soil organic matter decompostion coefficient - decmult decomposition coefficient multiplier; natural =1.0; agricultural =1.0 (1.2 in sensitivity test) - fertmin (gN/m²/month) = inorganic fertilizer input - fleach fraction of excess inorganic N that is leached - fligh (g Lignin/ g C) = lignin fraction of herbaceous litter C - fligw (g Lignin/ g C) = 0.3 = lignin fraction of woody litter C - fln2o = .01–.02 = fraction of leached N emitted as N₂O - fnav = 0.95 = fraction of mineral N available to plants - fosdep (gN/m²/month) = wet and dry atmospheric deposition of fossil fuel NO _x - fresph = 0.5 = fraction of herbaceous litter decomposition that goes to CO₂ respiration - fresps = 0.51 + .068 ^* sand = fraction of soil organic matter decomposition that goes to CO₂ respiration - frespw = 0.3 ^* (^* see comments in Section 2.3 under decomposition) = fraction of woody litter decomposition that goes to CO₂ respiration - fsoil = ratio of NPP measured on given FAO soil type to NPF_miami - fstruct = 0.15 + 0.018 ^* ligton = fraction of herbaceous litter going to structural/woody pool - fvn2o = .05–.10 = fraction of excess volatilized mineral N emitted as N₂O - fvol = .02 = fraction of gross mineralization flux and excess mineral N volatilized - fyield ratio of total agricultural NPP in a given country in 1980 to total NPP_miami of all displaced natural grids in that country - gimmob _h (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of herbaceous litter - gimmob _s (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of soil organic matter - gimmob _w (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of woody litter - graze (gC/m²/month) = C herbaceous biomass grazed by livestock - grazen (gN/m²/month) = N herbaceous biomass grazed by livestock - growth _h (gC/m²/month) = herbaceous litter incorporated into microbial biomass - growth _w (gC/m²/month) = woody litter incorporated into microbial biomass - gromin _h (gN/m²/month) = gross N mineralization due to decomposition and burning of herbaceous litter - gromin _s (gN/m²/month) = gross N mineralization due to decomposition of soil organic matter - gromin _w (gN/m²/month) = gross N mineralization due to decomposition and burning of woody litter - herb herbaceous fraction by weight of total biomass - leach (gN/m²/month) = leaching (& volatilization) losses of excess inorganic N - ligton (g lignin-C/gN) = lignin/N ratio in fresh herbaceous litter - LP _h (gC/m²/month)= C herbaceous litter production - LP (gC/m²/month) = C woody litter production - LPN _h (gN/m²/month) = N herbaceous litter production - LPN _W (gN/m²/month) = N woody litter production - manco2 (gC/m²/month) = grazed C respired by livestock - manlit (gC/m²/month) = C manure input (feces + urine) - n2oint (gN/m²/month) = intercept of N₂O flux vs gromin regression - n2oleach (gN/m²/month) = N₂O flux associated with leaching and volatilization of excess inorganic N - n2onat (gN/m²/month) = natural N₂O flux from soils - n2oslope slope of N₂O flux vs gromin regression - nbiomsh (gN/m²) = N herbaceous biomass pool - nbiomsw (gN/m²) = N woody biomass pool - nfix (gN/m²/month) = N₂ fixation + natural atmospheric deposition - nlittrh (gN/m²) = N herbaceous litter pool - nlittrw (gN/m²) = N woody litter pool - nmanlit (gN/m²/month) = organic N manure input (feces) - nmanmin (gN/m²/month) = inorganic N manure input (urine) - nmin (gN/m²) = inorganic N pool - NPP _acth (gC/m²/month)= actual herbaceous net primary productivity - NPP _actw (gC/m²/month) = actual woody net primary productivity - nvol (gN/m²/month) = volatilization losses from inorganic N pool - plntnav (gN/m²/month)= mineral N available to plants - plntup _h (gN/m²/month) = inorganic N incorporated into herbaceous biomass - plntup _w (gN/m²/month) = inorganic N incorporated into woody biomass - precip _ann (mm) = mean annual precipitation - precip _mon (mm) = mean monthly precipitation - pyroden _h (gN/m²/month) = burned herbaceous litter N that is pyrodenitrified to N₂ - pyroden _w (gN/m²/month) = burned woody litter N that is pyrodenitrified to N₂ - recyc fraction of N that is retranslocated before senescence - resp _h (gC/m²/month) = herbaceous litter CO₂ respiration - resp _s (gC/m²/month) = soil organic carbon CO₂ respiration - resp _w (gC/m²/month) = woody litter CO₂ respiration - sand sand fraction of soil - satrat ratio of maximum NPP to N-limited NPP - soiloc (gC/m²) = soil organic C pool - soilon (gN/m²) = soil organic N pool - temp _ann (°C) = mean annual temperature - temp _mon (°C) = mean monthly temperature Now at the NOAA Aeronomy Laboratory, Boulder, Colorado.     

Activity–composition relations for the calculation of partial melting equilibria in metabasic rocks

A set of thermodynamic models is presented that, for the first time, allows partial melting equilibria to be calculated for metabasic rocks. The models consist of new activity–composition relations combined with end‐member thermodynamic properties from the Holland & Powell dataset, version 6. They allow for forward modelling in the system NaO–CaO–KO–FeO–MgO–AlO–SiO–HO–TiO–FeO. In particular, new activity–composition relations are presented for silicate melt of broadly trondhjemitic–tonalitic composition, and for augitic clinopyroxene with Si–Al mixing on the tetrahedral sites, while existing activity–composition relations for hornblende are extended to include KO and TiO. Calibration of the activity–composition relations was carried out with the aim of reproducing major experimental phase‐in/phase‐out boundaries that define the amphibolite–granulite transition, across a range of bulk compositions, at ≤13 kbar.     

Reviews

GEOMORPHOLOGY by R. J. Chorley, S. A. Schumm and D. E. Sugden.’ 19 × 25 cm, xxiii and 605 pages. Methuen: London 1984 (ISBN 0 416 32590 4) $A39.95 (cloth).

THEMES IN GEOMORPHOLOGY edited by A. F. Pitty. 13 × 21 cm, 280 pages. Croom Helm: London 1985 (ISBN 0 7099 2066 0) $A49.50 (cloth).

DESERTS AND ARID LANDS edited by F. El‐Baz. 16 × 25 cm, vi and 222 pages. Nijhoff: The Hague 1984 (ISBN 90 247 2850 9) $US46.00 (cloth).

COASTAL GEOMORPHOLOGY IN AUSTRALIA edited by B. G. Thorn. 16 × 24 cm, xv and 349 pages. Academic Press: Sydney 1984 (ISBN 0 12 687880 3) $A49.50 (cloth).

KWONGAN: Plant Life on the Sandplain edited by J. S. Pate and J. S. Beard. University of Western Australia Press: Nedlands 1984 (ISBN 0 85564 230 0) $A25.00 (limp).

THEMES IN BIOGEOGRAPHY edited by J. A. Taylor. 22 × 14 cm, xxvii and 404 pages. Croom Helm: London 1984 (ISBN 0 7099 2428 3) $A25.95 (limp).

ENVIRONMENTAL IMPACT ASSESSMENT: A Practical Guide by C. F. Porter. 22 × 15 cm, xiii and 269 pages. University of Queensland Press: St Lucia 1985 (ISBN 0 7022 1699 2) $A35.00 (cloth).

THE CLIMATIC SCENE edited by M. J. Tooley and G. M. Sheail. 16 × 24 cm, xx and 306 pages. George Allen and Unwin: London 1985 (ISBN 0 04 551089 X) $A59.95 (cloth).

VOLCANIC HAZARDS: A Sourcebook on the Effects of Eruptions by R. J. Blong. 24 × 15 cm, xvi and 424 pages. Academic Press: Sydney 1984 (ISBN 0 12 107180 4) $A68.00 (cloth).

THE ECONOMICS OF BUSHFIRES: The South Australian Experience edited by D. T. Healey, F. G. Jarrett and J. M. McKay. 22 × 15 cm, x and 152 pages. Oxford University Press: Melbourne 1985 (ISBN 0 19 554669 5) $A19.99 (cloth).