584 research outputs found

    An application of LANDSAT multispectral imagery for the classification of hydrobiological systems, Shark River Slough, Everglades National Park, Florida

    Get PDF
    Multivariant hydrologic parameters over the Shark River Slough were investigated. Ground truth was established utilizing U-2 infrared photography and comprehensive field data to define a control network which represented all hydrobiological systems in the slough. These data were then applied to LANDSAT imagery utilizing an interactive multispectral processor which generated hydrographic maps through classification of the slough and defined the multispectral surface radiance characteristics of the wetlands areas in the park. The spectral response of each hydrobiological zone was determined and plotted to formulate multispectral relationships between the emittent energy from the slough in order to determine the best possible multispectral wavelength combinations to enhance classification results. The extent of each hydrobiological zone in slough was determined and flow vectors for water movement throughout the slough established

    Vegetation analysis in the Laramie Basin, Wyoming from ERTS-1 imagery

    Get PDF
    The author has identified the following significant results. The application of ERTS-1 imagery to vegetation mapping and identification was tested and confirmed by field checking. ERTS-1 imagery interpretation and density contour mapping allows definition of minute vegetation features and estimation of vegetative biomass and species composition. Large- and small-scale vegetation maps were constructed for test areas in the Laramie Basin and Laramie mountains of Wyoming. Vegetative features reflecting grazing intensity, moisture availability, changes within the growing season, cutting of hay crops, and plant community constituents in forest and grassland are discussed and illustrated. Theoretical considerations of scattering, sun angle, slope, and instrument aperture upon image and map resolution were investigated. Future suggestions for applications of ERTS-1 data to vegetative analysis are included

    Seed dispersers, seed predators, and browsers act synergistically as biotic filters in a mosaic landscape

    Get PDF
    In this study, we analize the functional influence of animals on the plants they interact with in a mediterranean mountain. We hypothesise that seed dispersers, seed predators, and browsers can act as biotic filters for plant communities. We analyse the combined effects of mutualistic (seed dispersal) and antagonistic (seed predation, herbivory) animal interactions in a mosaic landscape of Mediterranean mountains, basing our results on observational and experimental field. Most of the dispersed seeds came from tree species, whereas the population of saplings was composed predominantly of zoochorous shrub species. Seed predators preferentially consumed seeds from tree species, whereas seeds from the dominant fleshy-fruited shrubs had a higher probability of escaping these predators. The same pattern was repeated among the different landscape units by browsers, since they browsed selectively and far more intensely on tree-species saplings than on the surrounding shrubs. In synthesis, our work identifies the major biotic processes that appear to be favoring a community dominated by shrubs versus trees because seed dispersers, predators, and herbivores together favored shrub dispersal and establishment versus trees.This work was supported by Ministerio de Ciencia e Innovación (Spanish Government) Project CGL2011-29910 to R.Z. and by EU Marie Curie Fellowship to L.M (FP7-2011-IEF-300825)

    Field measurements on the CWD 5001 performed in the period 85-05-18 to 85-12-18

    Get PDF

    Remote sensing in Michigan for land resource management: Waterfowl habitat management at Pointe Mouillee

    Get PDF
    For many years the Pointe Mouillee State Game Area, located on the Lake Erie shoreline just south of Detroit, has been a prime waterfowl habitat. The usefulness of the site for this purpose has been impaired because of the gradual deterioration of the marshland and severe flooding and storms during the spring of 1973. Also, it has been proposed that a dredge spoils area be located in or near the marsh. To aid the future management of a diked refuge area of 148 hectares within the State Game Area, a detailed vegetation inventory was prepared by photointerpretation and a generalized vegetation inventory was obtained by processing multispectral scanner imagery. Also, an analysis was conducted to determine the magnitude of past losses of marshland and the possibilities of replacing this lost habitat. The analysis indicated that large additions to waterfowl habitat could be provided by changes in management of vegetation in existing sections of the State Game Area, through acquisition and conversion of adjacent land by the Michigan Department of Natural Resources, and by the proposed construction of a barrier dike offshore of Pointe Mouillee. Altogether, the various measures considered in this report could affect a total area of nearly 13 sq. km

    Application of LANDSAT images to wetland study and land use classification in west Tennessee, part 1

    Get PDF
    The author has identified the following significant results. densitometric analysis was performed on LANDSAT data to permit numerical classification of objects observed in the imagery on the basis of measurements of optical density. Relative light transmission measurements were taken on four types of scene elements in each of three LANDSAT black and white bands in order to determine which classification could be distinguished. The analysis of band 6 determined forest and agricultural classifications, but not the urban and wetlands. Both bands 4 and 5 showed a significant difference existed between the confirmed classification of wetlands-agriculture, and urban areas. Therefore, the combination of band 6 with either 4 or 5 would permit the separation of the urban from the wetland classification. To enhance the urban and wetland boundaries, the LANDSAT black and white bands were combined in a multispectral additive color viewer. Several combinations of filters and light intensities were used to obtain maximum discrimination between points of interest. The best results for enhancing wetland boundaries and urban areas were achieved by using a color composite (a blue, green, and red filter on bands 4, 5 and 6 respectively)

    Third Earth Resources Technology Satellite Symposium. Volume 3: Discipline summary reports

    Get PDF
    Presentations at the conference covered the following disciplines: (1) agriculture, forestry, and range resources; (2) land use and mapping; (3) mineral resources, geological structure, and landform surveys; (4) water resources; (5) marine resources; (6) environment surveys; and (7) interpretation techniques

    Floristic Composition and Community analysis of Gendo Moist Montane Forest of East Wellega, Western Ethiopia

    Get PDF
    Gendo Forest is one of the moist montane forests found in eastern highlands, East Wellega Zone, Ethiopia, containing diverse animals and plant species. The objectives of the present study were to investigate floristic composition and community structure to produce floristic document and appropriate recommendation based on the outcome of the study. Seventy two plots each 20 m X 20 m, 400 m2 were laid along eight transect lines along elevation gradient in systematic sampling. About 168 species, belonging to 140 genera and 65 families were recorded from the field data of Gendo Forest. The two most diverse families were Asteraceae, with 18 (12.9%) genera and 24 (14.3%) species and Fabaceae 17 (12.1%) genera and 21 (12.5%) species. The next large families were Poaceae with 7 (5%) genera, 8 (4.76%) species, Acanthaceae, Euphorbiaceae and Lamiaceae each having 6 (4.3%) genera and 8, 6, and 7 species respectively while the rest 59 families were containing 1-3 species. There were about 33 (19.6) trees, 56(33.3%) shrubs and 79 (47%) herbs were recorded. There were also 15 (9.9%) climbers. There were about 18 endemic species, 2 (1.2%) trees, 2 (1.2%) shrubby tree, 4 (2.5%) shrubs and 8 (4.8%) herb. About 12 (6.9%) and 152 (90.5%) of the total species documented were monocots and dicots respectively while 2 (1.2%) and another 2 (1.2%) were ferns and gymnosperms respectively. Only 3 (1.8%) species were recorded as hemi-parasitic plants. Gendo Forest also contained 9 (5.3%) of those 24 economically recognized national timber tree species (EFAP, 1994). Moreover, since the forest is yet not recognized in forest priority areas, it is recommended that it should be included in forest priority areas for further conservation and management. Keywords: Gendo Forest, Floristic composition, Moist Montane Forest, Plant Community

    ERTS-1 investigation of wetlands ecology

    Get PDF
    The author has identified the following significant results. Data from aircraft can be used for large scale mapping where detailed information is necessary, whereas Landsat-1 data are useful for rapid mapping of gross wetland boundaries and vegetative composition and assessment of seasonal change plant community composition such as high and low growth forms of Spartina alterniflora, Juncus roemarianus, and Spartina cynosuroides. Spoil disposal and wetland ditching activities may also be defined. Wetland interpretation is affected by tidal stage; drainage patterns are more easily detected at periods of low water. Species discrimination is easier at periods of high water during the growing season; upper wetland boundaries in fresh water tidal marshes are more easily delineated during the winter months when marsh vegetation is largely dead or dormant. Fresh water discharges from coastal streams may be inferred from the species composition of contiguous wetlands

    Quantitative Comparison of Plant Community Hydrology Using Large-Extent, Long-Term Data

    Get PDF
    Large-extent vegetation datasets that co-occur with long-term hydrology data provide new ways to develop biologically meaningful hydrologic variables and to determine plant community responses to hydrology. We analyzed the suitability of different hydrological variables to predict vegetation in two water conservation areas (WCAs) in the Florida Everglades, USA, and developed metrics to define realized hydrologic optima and tolerances. Using vegetation data spatially co-located with long-term hydrological records, we evaluated seven variables describing water depth, hydroperiod length, and number of wet/dry events; each variable was tested for 2-, 4- and 10-year intervals for Julian annual averages and environmentally-defined hydrologic intervals. Maximum length and maximum water depth during the wet period calculated for environmentally-defined hydrologic intervals over a 4-year period were the best predictors of vegetation type. Proportional abundance of vegetation types along hydrological gradients indicated that communities had different realized optima and tolerances across WCAs. Although in both WCAs, the trees/shrubs class was on the drier/shallower end of hydrological gradients, while slough communities occupied the wetter/deeper end, the distribution ofCladium, Typha, wet prairie and Salix communities, which were intermediate for most hydrological variables, varied in proportional abundance along hydrologic gradients between WCAs, indicating that realized optima and tolerances are context-dependent
    • …
    corecore