TY - JOUR
T1 - Effects of Caragana microphylla patch and its canopy size on "islands of fertility" in a Mongolian grassland ecosystem
AU - Kondo, Junji
AU - Hirobe, Muneto
AU - Yamada, Yoshihiro
AU - Undarmaa, Jamsran
AU - Sakamoto, Keiji
AU - Yoshikawa, Ken
PY - 2012/1/1
Y1 - 2012/1/1
N2 - In arid and semiarid regions, variations in "islands of fertility" accompanied by discontinuous vegetation is frequently observed. However, the effects of vegetation patches on soil, including the influence of canopy size, are not fully understood, particularly under conditions of severe grazing. We examined the effects of patches of mound-forming shrub, Caragana microphylla, and the plant's canopy size on these islands of fertility in a heavily grazed Mongolian grassland. In 11 patches with various canopy sizes (32. 5-180 cm in diameter), we compared the chemical properties of soils among three microsites: Mound, Below, and Around, which were inside, below, and outside of C. microphylla mounds, respectively. Total carbon (C) and most essential elements for the plants were more concentrated in Mound, but total nitrogen (N) and nonlimiting elements, such as exchangeable sodium (Na), did not significantly differ among microsites. Larger canopies more strongly affected the enrichment of total C and most essential elements, including total N, in Mound. These results suggest that C. microphylla patches substantially enrich total C and most essential elements and that the extent of enrichment was intensified with canopy size. However, under severe grazing, total N may be relatively more affected by the redistribution of resources through grazing, particularly when the canopy size is small.
AB - In arid and semiarid regions, variations in "islands of fertility" accompanied by discontinuous vegetation is frequently observed. However, the effects of vegetation patches on soil, including the influence of canopy size, are not fully understood, particularly under conditions of severe grazing. We examined the effects of patches of mound-forming shrub, Caragana microphylla, and the plant's canopy size on these islands of fertility in a heavily grazed Mongolian grassland. In 11 patches with various canopy sizes (32. 5-180 cm in diameter), we compared the chemical properties of soils among three microsites: Mound, Below, and Around, which were inside, below, and outside of C. microphylla mounds, respectively. Total carbon (C) and most essential elements for the plants were more concentrated in Mound, but total nitrogen (N) and nonlimiting elements, such as exchangeable sodium (Na), did not significantly differ among microsites. Larger canopies more strongly affected the enrichment of total C and most essential elements, including total N, in Mound. These results suggest that C. microphylla patches substantially enrich total C and most essential elements and that the extent of enrichment was intensified with canopy size. However, under severe grazing, total N may be relatively more affected by the redistribution of resources through grazing, particularly when the canopy size is small.
KW - Livestock grazing
KW - Microsite
KW - Semiarid
KW - Shrub
KW - Soil nutrient
KW - Vegetation mound
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U2 - 10.1007/s11355-010-0133-0
DO - 10.1007/s11355-010-0133-0
M3 - Article
AN - SCOPUS:84555177791
VL - 8
SP - 1
EP - 8
JO - Landscape and Ecological Engineering
JF - Landscape and Ecological Engineering
SN - 1860-1871
IS - 1
ER -