ORIGINAL ARTICLE
Response of degraded vegetation to introduction of
prescribed burning or mowing management in a Mongolian
steppe
Asuka Koyama
1,2
, Daisuke Kubo
1
, Yu Yoshihara
3
, Undarmaa Jamsran
4
and Toshiya Okuro
1
1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
2 Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan
3 Graduate School of Agricultural Science, Tohoku University, Ohsaki, Miyagi, Japan
4 Center for Ecosystem Study, Mongolian State University of Agriculture, Ulaanbaatar, Mongolia
Keywords
Artemisia adamsii; ecosystem management;
raunkiaer life form; resprouting.
Correspondence
Asuka Koyama, Forestry and Forest Products
Research Institute, 1 Matsunosato, Tsukuba,
Ibaraki 305-8687, Japan.
Email: asukoyama@gmail.com
Received 9 February 2015;
accepted 12 September 2015.
doi: 10.1111/grs.12113
Abstract
The understanding of the effectiveness of prescribed burning and mowing as
restoration tools of degraded grasslands is important for dryland rangeland
management. We examined the effects of spring prescribed burning or seasonal
mowing treatments on the degraded vegetation dominated by an unpalatable
subshrub, Artemisia adamsii, in grazed Mongolian steppe. Spring burning was
conducted in 2013, and three types of mowing treatments (spring, previous
summer, and previous summer and autumn) were conducted with varying sea-
sons and frequency, respectively. Soil samples were collected immediately after
the spring treatments. Four months after the spring treatments, total plant bio-
mass, the numbers of flowering shoots and florets per shoot of A. adamsii were
compared among the treatments. Plant biomass was divided into A. adamsii
and herbaceous plants (forbs and graminoids) with different Raunkiaer life
forms (chamaephytes, hemicryptophytes and geophytes). Soil properties and
total plant biomass were not different among the treatments. For A. adamsii,
the biomass and number of flowering shoots were decreased by spring burning
and growing-season mowing, owing to the disappearance of woody-shoots of
A. adamsii. On the other hand, spring mowing had less negative impact on the
biomass of A. adamsii due to an increase of the newly-formed shoots. The bio-
mass of perennial herbaceous-plants was not affected by spring burning,
regardless of the life form, whereas that of the geophytic sedge Carex duriuscula
increased in the summer-and-autumn mowing. Thus, spring burning and
growing-season mowing have the potential to control undesirable subshrubs
due to loss of the woody shoots, while spring mowing may not be recom-
mended as a useful management tool in the Mongolian steppe. Our results
emphasize that the introduction of these management tools for degraded-
grassland restoration in dryland rangelands needs more long-term evaluation
considering the relation with external factors such as climate variation and
grazing impact.
Introduction
In arid and semiarid Mongolian rangelands, land degra-
dation has progressed under overgrazing by livestock,
with a shift from vegetation dominated by palatable
grasses to that dominated by unpalatable forbs and weeds
(Fernandez-Gimenez and Allen-Diaz 2001; Sasaki et al.
2008, 2013b). The predominance of an unpalatable sub-
shrub Artemisia adamsii Besser in overgrazed grasslands is
a serious concern for rangeland management in the Mon-
golian steppe (Fernandez-Gimenez and Allen-Diaz 2001;
Okayasu et al. 2012; Tsubo et al. 2012). Restoration of
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