Community perception and participation,prospects in management of forests in marginal lands of Sudan

Fuelwood Development for Energy in Sudan project (GCP/SUD/033/NET) is undertaking research to formulate management plans for Sudan ecologically marginal forests. Rawashda and Wad Kabu forests are taken as examples to initiate sound plans. It is believed that the study of socio-economic parameters of forests users is an essential component to achieve such plan. This study is also fundamental for attaining an integrated land use system, as a prime option of natural resource use. This study is, consequently, aiming at:

1. Providing the base line information of the different communities identified in Tab 3 and using the two forests.
2. Examine people's attitude, perception, participation options in maintenance and management of the two forests. Such parameters are also vital for adoption of an integrated land use strategy in the future.
3. Based on (i) and (ii) to outline broadly the most relevant plan of management land use strategy to be adopted, based on community self-generated options of institutions and objectives of use.

The main findings in this context can be summarized in the following:

1. A complex pattern of economic activities (Tab 3) ranging from pure pastoral nomadism to modern mechanized farming, still characterized by combination of related activities of agricultural/livestock breeding, agriculture/forest resource use, etc. This diversity in activities, which is mostly dependent on the natural resource base, gives a sound base for any option of an integrated land use system.
2. Perception and attitude analysis have revealed a growing awareness of the role of the forest resources in the economy as source of grazing, domestic needs and source of income. This awareness is supported by willingness to participate in any integrated land use plan, yet from a different stand point and objective. Preference of self-generated channels is quite evident, but with a specified role of the government.
3. The major finding is that, and among all communities, the situation is mature for action, although at different levels.

Therefore, each community could be approached along relevant lines of action, as an initial phase before attaining a comprehensive land use plan. On-farm trials (OFTs) or in-herd trials seem to be more relevant compared with expert controlled trials. Any plan of action needs to be preceded by revision of present land tenure systems, establishing grass-root institutions, reorientation of concerned government departments, intensive extension programme and careful formulation of projects, execution and follow-up plans. Such steps need to be geared to narrow the ‘Perception gap’ of development between participants or users and planners.     

The Araguainha astrobleme/Central Brazil

The following facts have supported the origin of the Araguainha circular structure in Central Brazil by a meteoritic impact:

1. the almost circular contour
2. the impact-morphologic sequence including a central uplift, ring walls and a basin rim of escarpments
3. outcrops of suevites and mixed breccias
4. the evidence of shock metamorphism
5. the presence of shatter cones, and
6. negative anomalies of the total intensity of the magnetic field at the center of the ring structure.

     

Geologische und geochemische Untersuchungen im Zentralgneis und in der Greiner Schiefer Serie (Zillertaler Alpen,Tirol)

Geologic, petrological and geochemical investigations have been carried out in the western part of the “Zillertaler Alpen”. Important results are:

1. The premetamorphic material of the Greiner series consists of conglomerates, breccias, arcosic-sandstones or greywackes, bituminous shales, volcanic lavas and tuffs.
2. The southern part of the “Zentralgneis” shows a differentiation trend from alkaline granite to quarzdiorite with predomination of granodiorite.
3. Chemical relationships of granodiorite to its restitic inclusions allow the supposition of a palingenetic origin of the granitic rocks.
4. At least two stages of metamorphism can be differentiated.
5. Parts of the Greiner series, covered by triassic metasediments, are supposed to be of Permian age. A lower age boundary can not yet be given.
6. Some vertical, northeast striking faults with throws of more than 1 or 2 kilometers produced southward verging drag folds.
7. Geodynamic aspects, revealed from regional metamorphism and tectonics, are discussed.

     

Kyanite eclogites

Prior experimental work has shown that in the laboratory the mineralogy of eclogites is sensitive to the ratio of CaO ∶ MgO ∶ FeO and that the reaction pyroxene + kyanite?garnet + quartz proceeds to the right at high pressures in rocks rich in magnesium and to the left in rocks rich in calcium and iron. Typical basalts crystallized at high pressure never contain kyanite. The chemistry and mineralogy of a large number of naturally occurring eclogites show they belong to three classes.

1. Kyanite-free magmatic eclogites, rich in magnesium, from:
2. kimberlites
3. dunites and serpentinites.
4. Kyanite-bearing eclogites and grosspydites rich in CaO and low in FeO with intermediate MgO from:
5. kimberlites
6. gneisses.
7. Kyanite-free eclogites of metamorphic origin rich in iron with low magnesium and intermediate amounts of calcium from:
8. glaucophane schists
9. gneisses.

     

Forest condition and forest damages — contribution of remote sensing to different inventory approaches

The development of inventory activities in the field of forest damage assessment and monitoring during the last decade in Germany and the present state are recorded as far as remote sensing has been involved. Any forest inventory is influenced by external factors, and the resulting difficulties for an introduction of new technologies are described. The following tasks and/or methods are discussed:

-global approaches to deforestation monitoring

-working experience from local and regional case studies

-vegetation and vegetation-damage monitoring in ”urban forestry”

-sampling approaches for large areas

-the contribution of spectral signatures and satellite remote sensing to damage assessment

     

The structural geology of the Dalradian rocks of Slieve Gamph,Cos. Mayo and Sligo,Western Ireland

The paper presents novel information on the Caledonian orogeny in Ireland. A series of Dalradian (Upper Precambrian-Lower Cambrian) metasedimentary rocks occur as an envelope to a granitic igneous complex at Slieve Gamph, Western Ireland. These metasedimentary rocks have been deformed at several distinct times and evidence is shown for the following sequence of events:

1. formation of major nappe structures and a tectonic slide. The axial-plane traces of the folds probably trended N. E.-S. W.
2. formation of upright, gently plunging folds with axial-plane traces of the folds trending N. E.-S. W. Emplacement of the components of the Slieve Gamph igneous complex.
3. formation of a conjugate set of folds:
   1. Open folds with N. N. E.-S. S. W. trending axial-planes which dip to the east,
   2. Open folds with E.W. trending axial-planes which dip to the north.
4. formation of kink-bands, open and conjugate folds with an axialplane trace trending N. W.-S. E.

Late phase of faulting. No isotopic dates are available for these structural events.     

Thermodynamics of plagioclases I: Theory of the I\bar 1 - P\bar 1 phase transition in anorthite and Ca-rich plagioclases

Landau theory of the \(P\bar 1 - I\bar 1\) phase transition in Ca-rich plagioclases reveals the sensitivity of the phase transition behaviour to a) Al, Si disorder, b) structural replacement of Ca by Na, and c) inhomogeneities of lattice strains. The following effects are predicted:

1. A tricritical phase transition exists in fully ordered anorthite. Al, Si disorder and Na, Ca exchange lead to second order phase transitions.
2. The transition temperatures depend sensitively on the degree of Al, Si disorder and the chemical composition of the Ca-rich plagioclases. Increasing Na-content decreases the transition temperatures.
3. The thermal evolution of c and d reflections depends on the homogeneity of the crystal and do not necessarily reflect the temperature evolution of the macroscopic lattice strain. A simple quadratic dependence of the X-ray scattering intensity on the order parameter exists only for fully ordered, homogeneous anorthite.

The role of inhomogeneous Al, Si distributions and lattice relaxations are discussed including possible structural modulations.     

Environmental impacts by input of substances in landscapes of the District (Bezirk) of Leipzig,Germany

Problems of landscape and resource protection resulting from the intensification of land-use can be mastered only by intersectoral planning and a land management considering (landscape-)ecological principles right from the beginning. In the district of Leipzig ecological studies in the '80ies have focussed on:

1. Determination of the regional pattern of atmospheric immissions;
2. Registration of heavy metals in soil and vegetation;
3. Soil compaction, soil erosion;
4. Study of stress indicators in the aeration zone and in the top-most aquifer in order to examine barrier effects in the percolation process.

First results are discussed.     

Zur Anwendung der Kathodolumineszenz in der Karbonatpetrographie

Mn-activated cathodoluminescence can be used in several fields of carbonate petrography. It may, for instance, be possible to recognize

1. cement sequences and their correlation (Tab. 1, Figs. 1, 2, 4; Tab. 2, Fig. 1)
2. growth fabrics of skeletons (Tab. 2, Figs. 2, 3, 4; Tab. 3, Figs. 1, 2)
3. dolomitisation processes and problems (Tab. 1, Figs. 1, 2; Tab. 4, Fig. 2)
4. transformation paths from Mg-calcite to calcite and from aragonite to calcite (Tab. 2, Fig. 1; Tab. 3, Figs. 3, 4; Tab. 4, Fig. 1)
5. growth structures in certain types of ooids (Tab. 1, Fig. 4; Tab. 3, Fig. 3; Tab. 4, Fig. 1)
6. reworked skeletal particles (Tab. 3, Fig. 4)
7. phantom grains and fossil-outlines in a micro- or macrocrystalline groundmass (Tab. 4, Figs. 2, 3)
8. healed fissures crossing micro- or macrocrystalline carbonate rocks (Tab. 4, Fig. 4).

These are, however, no general luminescence criteria indicating the depositional environment. Luminescence of calcite and dolomite requires 20–40 ppm Mn, with the equipments used in this study. Aragonite is not yet investigated systematically. Zonal luminescence in carbonate cements may indicate changes of the chemical composition of the aquifer and may be used for “cement stratigraphy”. In skeletons it rather indicates physiological changes. While aragonitic skeletons lose their luminescence Zonation during replacement by calcite, Mg-calcite skeletons may keep parts of it, because their replacement preserves the original crystal fabric. Blotchy luminescence developes in Mg-calcitic particles during their adjustment to lower Mg-calcites by dissolution-precipitation processes in solutions with changing Mn/Fe-ratios.     

Comparative magma/xenolith relationships in some volcanic and plutonic rocks from the French Massif Central

A comparative study of xenoliths from lavas and granitic rocks of central France indicates that:

1. The evolution of the xenoliths is essentially the same in intermediate to acid lavas as in granites. The major factor in this evolution is the assimilation by the host magmas of the quartzofeldspathic components of the xenoliths, which then become Al, Fe, Mg-rich restites.
2. Liquid immiscibility between melted xenoliths and host magmas can only be postulated for acid xenoliths in alkali basalts.
3. The basic microgranular xenoliths in some granites do not show important compositional gaps with their host rocks, though they are regularly more basic. They can be considered as early segregations (cumulates).

     

Low temperature\lg f_{O_2 } - pH diagrams of sulfur isotope evolution in an equilibrium hydrothermal system

According to Sakai-Ohmoto's theory regarding the evolution of sulfur isotopes in hydrothermal systems, in conjunction of new data on chemical resaction equilibrium constants and equilibrium isotopic fractionation factors as well as on individual ion activity coefficients of aqueous sulfur species, the following lgfo₂.-pH diagrams are constructed:

1. mole fractions of aqueous sulfur species (X _i ),
2. stability fields of some minerals in the Fe-S-O system,
3. diagram depicting the oxidation-reduction-state ratio for aqueous sulfur species (R′)
4. isotopic compositions of sulfur compounds ( \(\delta S_1 ^{34} \) ).

     

Utilisation of loess for soil amelioration

In Hungary loess has long been used for soil reclamation. The main steps of the method are: horizon A and B are removed from a suitable area and their material is stockpiled at the margins of the resulting pit. The loess (horizon C), this way exposed, is excavated and spread over the salt affected soils to be improved then mixed with their upper layer. The pit is named in Hungarian digó (pit). The name of the reclamation process is the digo method or spreading of yellow earth. Digó method is mainly used for the amelioration of salt affected soils with an acid A horizon and its benefits are as follows:

1. The acidity of the horizon A is eliminated
2. The soil structure is improved
3. The amount of calcium (a plant nutrient) is increased
4. Soil fertility is improved continuously
5. The soil depth is extended which adds to the relative volume of the ground water table.

     

Geochemistry and origin of granitic rocks,Scourian Complex,NW Scotland

Concordant granite sheets from the granulite facies Scourian Complex, N.W. Scotland exhibit the following features:

1. a common planar fabric with their host pyroxene granulites;
2. the presence of an exsolved ternary feldspar phase;
3. a low-pressure, water-saturated minimum composition;
4. K/Rb ratios (450–1,350) distinctly higher than most upper crustal granites but similar to the surrounding granulites;
5. low absolute concentrations of the rare earth elements (REEs), light REE enrichment, and large positive Eu anomalies.

It is proposed that the granite sheets have originated by anatexis of gneisses undergoing granulite facies metamorphism — gneisses that were already essentially dry and depleted in incompatible elements. Their unusual trace element chemistry may be explained by either disequilibrium melting and/or sub-solidus reequilibration of the granite sheets with the surrounding gneisses. Isotopic and trace element data suggest that cross-cutting, potash-rich pegmatites represent reworking of the granite sheets during a later amphibolitization.     

Natural hazard mapping

Systematic natural hazard mapping in Japan was started after WW II using aerial photographs. Analysing the interaction between disaster occurrence and land conditions is the most useful method for establishing the disaster prediction system for three types of disaster, flood disaster, mass-movement disaster, and earthquake disaster, which are strongly related to land conditions. A series of maps on natural hazards were established based on the results analysed. In our opinion, the following problems of natural hazard mappings remain so far unsolved:

1. No clear distinction is made between natural hazard mapping and land classification.
2. Organization of information for natural hazard prevention is not yet established.
3. There is no established earthquake disaster prevention map.
4. Utilization of new machines and tools is inadequate.
5. Effect of human activity is not estimated.

     

Determination of total carbonate content in some representative loess-paleosol profiles

Samples taken from loess and paleosols were examined for carbonate content. The main results were as follows:

1. The carbonate content measured differed significantly when the samples were analysed jointly with the concretions occurring in them or separately from these constituents.
2. Solubility of different carbonates (calcite, dolomite, aragonite etc.) was found different. This factor also might have influenced the measured total amounts of carbonates.

     

Altération supergène des protores à grenats manganésifères dans quelques gisements d'Afrique de l'Ouest

The wet tropical weathering of Precambrian spessartite quartzites leads to the formation of secondary oxidized ores. These ores result from different successions of superimposed elementary processes, among them:

garnet hydrolysis: Mn, Ca, and Fe are leached, and only an amorphous, silicoaluminous phase remains.

lithiophorite neoformation: Added manganese combines with alumina of the amorphous, Si-Al products.

leaching: Voids appear in the central part of the weathered garnets. They may widen, leaving only the quartz matrix with polyhedric voids.

epigenic replacement: The quartz is replaced by cryptomelane, while the garnets may remain unweathered.

The various ore types are characterized by the sequence of transformations and by the volumes that each transformation affects. These transformations are old because they are observed not only in situ ores but also in removed detrital ores. In the same way the major part of the accumulated stocks of oxidized ores must be old.     

Quartz-grain surfaces of debris flow material in the marginal mountains of Tibet

Debris flow is a natural phenomenon which occurs on steep slopes of mountain regions. Very often morainic material and nonmorainic sediments, such as debris flow material, fluvial and other sediments, are mixed in the marginal mountain systems of the Tibetan Plateau. The study of quartz-grain surface features of debris flow has an important significance for differentiating between different origins of Quaternary sediments. Features of quartz-grain in debris flow will be described as below:

1. The predominant shapes of quartz grains are irregular.
2. The degree of roundness of grains is in general are angular to subangular in shape.
3. The textures of quartz-grains in debris flows are conchoidal fractures, parallel steps and mechanical V-marks. Parallel steps are especially abundant. Their presence is the most characteristic indicator of debris flow sand, aiding in the differentiation between debris flow and glacial sand.
4. Fresh cleavage planes are extremely flat.

     

Petrochemistry of the volcanic rocks of the Island of Principe,Gulf of Guinea

Principe is one of the volcanic centres comprising the Cameroun line in West Africa. The volcanic rocks can be divided into two stratigraphic units:

1. Younger lava series — basanite and nephelinite overlying.
2. Older lava series — transitional to mildly alkaline basalt and hawaiite.

These units lie on a basement of palagonite breccias of tholeiitic affinities. The basic lavas are intruded by plugs ranging in composition from tristanite to phonolite and are overlain by phonolite lavas. These rocks form two chemically and mineralogically distinct suites:

1. Phonolites which evolved by low pressure crystal fractionation of the younger lava series basanitic magma, and
2. Tristanite — trachyte — trachyphonolite suite which may have evolved by high pressure crystal fractionation of the older lava series magma.

     

The “South-Italian City” — a cultural-genetic type of city

The “South-Italian city” is characterized at four different levels as an independent cultural-genetic city-type:

1. The characteristics arrangement of the functional areas and the residential areas of different social groups is represented in a model.
2. From the model, developments and changes in the arrangement of the functional areas can be identified which clearly deviate from those which are derived from the universal city model.
3. Some of the structural individuality can be directly explained by the peculiar features of the respective social and economic history.
4. Some of the special features must, however, be traced back to a wider historico-cultural background. Through this run processes which flow through the universal city development in similar forms, to the deviating structure of the “South-Italian city”.

     

Phase equilibria among pumpellyite,lawsonite, epidote and associated minerals in low grade metamorphic rocks

Phase relations of pumpellyite, epidote, lawsonite, CaCO₃, paragonite, actinolite, crossite and iron oxide are analysed on an Al-Ca-Fe³⁺ diagram in which all minerals are projected from quartz, albite or Jadeite, chlorite and fluid. Fe²⁺ and Mg are treated as a single component because variation in Fe²⁺/Mg has little effect on the stability of phases on the diagram. Comparison of assemblages in the Franciscan, Shuksan, Sanbagawa, New Caledonia, Southern Italian, and Otago metamorphic terranes reveals several reactions, useful for construction of a petrogenetic grid:

1. lawsonite+crossite + paragonite = epidote+chlorite + albite + quartz + H₂O
2. lawsonite + crossite = pumpellyite + epidote + chlorite + albite+ quartz + H₂O
3. crossite + pumpellyite + quartz = epidote + actinolite + albite + chlorite + H₂O
4. crossite + epidote + quartz = actinolite + hematite + albite + chlorite + H₂O
5. calcite + epidote + chlorite + quartz = pumpellyite + actinolite + H₂O + CO₂
6. pumpellyite + chlorite + quartz = epidote + actinolite + H₂O