Showing papers on "Vegetation (pathology) published in 1977"
807 citations
192 citations
183 citations
01 Mar 1977
130 citations
125 citations
TL;DR: In this paper, in situ spectral reflectance of a blue grama grass canopy sampled with approximately equal amounts of standing live and standing dead vegetation has identified spectral regions between 0.35 and 0.80 μm where the total wet biomass, total dry biomass, and leaf water content can be spectrally estimated.
117 citations
Book•
01 Jan 1977
TL;DR: In this paper, the influence of voles and lemmings on the vegetation in a coniferous forest during a 4-year period in northern Sweden was studied and the authors found that voles had a significant influence on vegetation in the forest.
Abstract: The influence of voles and lemmings on the vegetation in a coniferous forest during a 4-year period in northern Sweden
116 citations
TL;DR: Assessment of effects of shade, roots, and litter of mesquite trees on understory vegetation and microenvironmental factors in the mesquite-desert grassland indicated increased soil moisture made available by mesquite removal and in excess of that lost by evaporation was reflected in greater vegetative cover.
Abstract: Highlight: Studies were conducted in the mesquite-desert grassland to assess effects of shade, roots, and litter of mesquite trees on understory vegetation and microenvironmental factors. Elimination of mesquite shade and root action increased foliar cover of understory vegetation in the canopy zone from 19% with intact mesquite to 24%. Replacement of mesquite shade with artificial shade screens further increased understory vegetative cover to 32%. Only forbs responded to elimination of mesquite roots in open areas. Vegetation responses indicated improved soil moisture in the canopy zone with both treatments, but there were no detectable soil moisture differences among treatments during the major part of the growing season. Greater vegetal cover with noshade and artificial shade treatments was apparently associated with differential utilization of moisture compared with the mesquite shade treatment. Increased soil moisture made available by mesquite removal and in excess of that lost by evaporation was reflected in greater vegetative cover. With artificial shade, potential evaporation was similar to that for natural shade-thus increased moisture was utilized for growth of understory vegetation.
105 citations
TL;DR: Differences in water availability in their food appeared to be the primary reason for differences in local distributional patterns of the latter two species, both of which have high water requirements.
Abstract: Napeozapus insignis and Blarina brevicauda were more abundant in sites with greater vegetation cover, especially herbaceous vegetation; Peromyscus leucopus and P. maniculatus were more abundant in ...
TL;DR: Fossil pollen records from peat bogs are used to propose a 16,000-year paleoenvironmental sequence for central Texas as mentioned in this paper, showing that during the late Fullglacial, central Texas was covered by an open woodland deciduous forest with some conifers present.
Abstract: Fossil pollen records from peat bogs are used to propose a 16,000‐year paleoenvironmental sequence for central Texas. Evidence suggests that during the late Fullglacial, central Texas was covered by an open woodland deciduous forest with some conifers present. During the Lateglacial, this vegetation appears to have been replaced by a proposed parkland vegetation dominated by grasses but still containing some arboreal elements. Finally, during the Postglacial period there was a continued loss of more arboreal elements resulting in the establishment of the central Texas Post Oak Savanna vegetation of today.
01 Jan 1977
TL;DR: In this article, the decomposition of metal tolerant vegetation growing on mine waste containing high concentrations of lead and zinc was studied and compared with those on an adjacent uncontaminated site.
Abstract: Aspects of the decomposition of metal tolerant vegetation growing on mine waste containing high concentrations of lead and zinc were studied and compared with those on an adjacent uncontaminated site. High concentrations of Pb and, to a lesser extent, Zn, accumulated in metal-tolerant grass. Retarded decomposition of this vegetation as compared with that on the uncontaminated site was indicated by a greater accumulation of litter, less humus formation, reduced soil urease activity and smaller microbial and microfaunal populations. Some evidence for increased metal tolerance in microbes from the mine waste was obtained. Concentrations of lead tolerated under laboratory conditions were much lower than those extracted from the mine waste and its vegetation, probably due to the lack of an accurate method for assessing the availability of lead in soil and vegetation.
Journal Article•
TL;DR: In this article, the effect of vegetation on the spectral reflectance of earth materials in the wavelength region of 0.45 to 2.4 microns is determined by computer averaging of in situ acquired spectral data.
Abstract: The effect of naturally occurring vegetation on the spectral reflectance of earth materials in the wavelength region of 0.45 to 2.4 microns is determined by computer averaging of in situ acquired spectral data. The amount and type of vegetation and the spectral reflectance of the ground are considered. Low albedo materials may be altered beyond recognition with only ten per cent green vegetation cover. Dead or dry vegetation does not greatly alter the shape of the spectral reflectance curve and only changes the albedo with minimum wavelength dependency. With increasing amounts of vegetation the Landsat MSS band ratios 4/6, 4/7, 5/6, and 5/7 are significantly decreased whereas MSS ratios 4/5 and 6/7 remain entirely constant.
Journal Article•
TL;DR: The results indicated a possibility of an increase in cadmium in animal tissues depending upon the increased residues of this metal in the environment.
TL;DR: In a small drainage basin in the Peak District rates of soil erosion were measured between October 1966 and September 1968 The vegetated margins of ground denuded of vegetation (scars) were retreating by 93 mm per annum and rills and sheet wash removed annually from these scars up to 34 t ha−1 soil Erosion was taking place primarily within Agrostis-Festuca swards and also in heather moor, but not on peat-covered slopes under cotton grass (Eriophorum vaginatum) moor.
Abstract: In a small drainage basin in the Peak District rates of soil erosion were measured between October 1966 and September 1968 The vegetated margins of ground denuded of vegetation (scars) were retreating by 93 mm per annum and rills and sheet wash removed annually from these scars up to 34 t ha−1 soil Erosion was taking place primarily within Agrostis-Festuca swards and also in heather moor, but not on peat-covered slopes under cotton grass (Eriophorum vaginatum) moor The Agrostis-Festuca sward supported a higher sheep population than did the other vegetation types In May 1974 most scars had been colonized by vegetation; this was related to a marked decrease in sheep numbers in 1969 and not to climatic factors
01 Jan 1977
TL;DR: In this article, an account of the distribution down the River Swale in summer 1976 of 132 species of photosynthetic plants which are recognizable macroscopically is given, and some environmental data are included.
Abstract: SUMMARY. An account is given of the distribution down the River Swale in summer 1976 of 132 species of photosynthetic plants which are recognizable macroscopically. Some environmental data are included. The river may be regarded as falling into three zones, both with regard to its physical features and its type of vegetation. The upper zone has rocky substrata, fast flows and a macrophytic vegetation largely of bryophytes; the middle zone has unconsolidated substrata and the macrophytic vegetation is relatively sparse; the lower zone is silted and the macrophytic vegetation consists largely of angiosperms. The flora of the Swale is compared with that of the Tees, since eventually the former is likely to receive water from the latter as part of a major water transfer scheme. Eleven species of ‘river’ angiosperm which are present in the Tees above the projected abstraction point are absent from the Swale above the inflow point.
01 Jan 1977