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A landslide inventory and a detailed geomorphological analysis were done, focusing on the identification of mass movement related morphologies, and with the purpose of making a preliminary landslide susceptibility analysis of the Viejo river basin, Puriscal. From a geomorphological point of view, denudational units are predominant. They include regions severely affected by mass movements and represent 92,3% of the basin area. Geomorphology proved to be an important conditioning factor for landslide susceptibility and a valuable instrument for the interpretation of historical dynamics of the geoforms and past landslide events, with the aim of validating the variables and methodologies of susceptibility zonation to be considered. [ABSTRACT FROM AUTHOR]

Hinchinbrook Island, a wilderness National Park, lies closely adjacent to the Australian mainland within the boundaries of the Great Barrier Reef World Heritage area. The mangroves that occupy much of its shoreline and the neighbouring mainland intertidal are major features. Recent preliminary surveys have revealed considerable floristic variety at local scales and, over the total area, often intricate vegetal patterning (Bunt, 1997). It is the intention now to define the most conspicuous features in numeric and graphical terms. Particular attention has been given to differences in shore normal species sequencing within the study area and to the complexities associated with overlap in species distributions. [ABSTRACT FROM AUTHOR]

Considerable variety is to be found in zonal expression within the mangroves of riverine estuaries in tropical northeastern Australia. Detailed surveys have shown that this is partly due to differences in the sequencing order of taxa across the intertidal surface (Bunt, 1996). However, it is evident that the clarity and pattern of zonation may also be affected by overlap in species distributions. The need to consider the latter in detail arose in the course of ongoing surveys. For the latter purpose, procedures are here described that enable complex field data sets to be analysed in numeric and graphical terms. Data for a single transect from the Endeavour river have been used to explain the methods used and to illustrate results. [ABSTRACT FROM AUTHOR]

A palynological investigation of 164 samples from 18 water wells in northern Kordofan, Sudan, enabled the recognition of five informal zones based on pollen and spore assemblages ranging in age from Albian to Maastrichtian. The youngest (late Campanian-Maastrichtian) assemblages are restricted to the Bagbag Basin, whereas Albian-Cenomanian (to Turonian) sediments are widespread to the east and west of the Bagbag area. Impressions of Salvinia floating leaves from outcrops of the upper Hamrat el Wuz Formation, western part of the study area, are among the oldest occurrences of this water fern and indicate a Campanian-Maastrichtian age for these sediments. The vertical distribution of hygrophilous (pteridophytic spores) versus xerophilous (ephedroids and possibly small, weakly sculptured tricolporates) elements in the palynofloras suggests widespread moist or even aquatic habitats in the Albian-Cenomanian and Campanian-Maastrichtian. A shift towards drier conditions occurred in the late Cenomanian-Turonian. Throughout the Cretaceous, however, there may have been extensive arid/semiarid areas of non-deposition and seasonally dry periods. Some characteristics of the local palynofloras are attributed to its inner continental position. Rare Albian-Cenomanian and Campanian-Maastrichtian dinoflagellates could be interpreted as lacustrine phytoplankton rather than as evidence for marine influence. [ABSTRACT FROM AUTHOR]

The study examines vegetation – environment relationships. Vegetation measurements included species frequency, density, diameter and tree height, while environmental measurements were soil particle size distribution, acid properties (pH, Al, SO4), nutrient cations (Ca, Na, Mg, K), organic carbon, nitrogen, phosphorus and chloride content. Nypa fruticans was the dominant species in the A stratum (> 3 m tall) while Rhizophora mangle was dominant in the B stratum (1–3 m tall). The C stratum (< 1 m tall) was dominated by mangrove, Nypa and Raphia saplings. Silt was dominant and the most variable particle size fraction. A principal components analysis of the soil data indicated the first three dominant components influencing the vegetation were salinity, nutrient and soil texture. Tree height and density correlated highly with the salinity and soil texture gradients (P < 0.01), while basal area correlated with salinity and nutrient gradients (P < 0.01). While Avicannia africana in the A stratum was influenced largely by the salinity and soil texture gradients. Nypa fruticans in the B stratum was influenced by salinity and nutrients. [ABSTRACT FROM AUTHOR]