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Titolo:
Grassland desertification by grazing and the resulting micrometeorologicalchanges in Inner Mongolia
Autore:
Li, SG; Harazono, Y; Oikawa, T; Zhao, HL; He, ZY; Chang, XL;
Indirizzi:
Univ Tsukuba, Inst Biol Sci, Tsukuba, Ibaraki 3058572, Japan Univ TsukubaTsukuba Ibaraki Japan 3058572 sukuba, Ibaraki 3058572, Japan Natl Inst Agroenvironm Sci, Tsukuba, Ibaraki 3058604, Japan Natl Inst Agroenvironm Sci Tsukuba Ibaraki Japan 3058604 i 3058604, Japan Chinese Acad Sci, Desert Res Inst, Lanzhou 730000, Gansu, Peoples R China Chinese Acad Sci Lanzhou Gansu Peoples R China 730000 su, Peoples R China
Titolo Testata:
AGRICULTURAL AND FOREST METEOROLOGY
fascicolo: 2-3, volume: 102, anno: 2000,
pagine: 125 - 137
SICI:
0168-1923(20000512)102:2-3<125:GDBGAT>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
CLIMATE CHANGE; DROUGHT; DEFORESTATION; SAND;
Keywords:
grassland; grazing intensity; micrometeorology; desertification; albedo;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Li, SG Univ Tsukuba, Inst Biol Sci, Tsukuba, Ibaraki 3058572, Japan Univ Tsukuba Tsukuba Ibaraki Japan 3058572 Ibaraki 3058572, Japan
Citazione:
S.G. Li et al., "Grassland desertification by grazing and the resulting micrometeorologicalchanges in Inner Mongolia", AGR FOR MET, 102(2-3), 2000, pp. 125-137

Abstract

Overgrazing is one of the most primary causes of desertification in semi-arid zones of China. From 1992 to 1994 we conducted a grazing experiment in Naiman (lat. 42 degrees 58'N, long. 120 degrees 43'E, 345 m asl), Inner Mongolia, China to elucidate desertification mechanisms. Our experimental field, which was covered with some short grasses, legumes and forbs, included four plots where grazing sheep numbers differed (0, 3, 6, or 9 individuals). Micrometeorological measurement data were analyzed using the Bowen ratio energy balance method. Ground surface reflectivity (albedo) increased with grazing intensity. The overgrazed plot had been desertified after 3 year's grazing experiment. Albedo can be regarded as an important indicator of potential grassland desertification. When desertification occurs, then albedo will exceed a critical value. Partitioning of net radiation exhibited distinct patterns among the four plots as a result of the interplay between albedo and in situ vegetation. Ratios of the net radiation or net available radiation to solar radiation tended to decrease with increasing grazing intensity. Bur this pattern of changes was largely affected by soil moisture regime and vegetation status during the measurements. Grazing also remarkably affected wind regimes over the grazing experimental plots through altering surface roughness. Especially, sustained overgrazing decreased surface roughness length so substantially that wind could act directly on sandy grasslandsurface to initiate desertification. A permissible grazing capacity of thestudied temperate semi-arid grassland was also proposed for future grassland management. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 14:04:22