These are descriptions of the training sites chosen as representative of grassland community type classes in western and central Xilingol Aimag; they were chosen on the basis of field survey in August 1996, the Grassland Type map of the Series Resources Maps of Inner Mongolia Autonomous Region, PRC, 1990 (Yong & Cui, 1990) and the AVHRR imagery itself. The sites are located in different steppe zones; here are the nominal boundaries of these zones, superimposed on a map of average annual precipitation. The training site locations can also be seen over a blue/yellow false colour composite here, from where the photos can also be accessed. A land cover map of the area in the mid-1980s and a standard FCC are also available.
Stipa gobica desert steppe (site A). Short tough
perennial grass able to withstand the wide annual variation in
temperature. The soil surface is littered with stones of various
colours, often white or red. The terrain is very level and vegetation
very homogeneous in its distribution (looks like wallpaper from a
distance); see this photo. Local herders
report increasing invasion of their pastures by annuals in parts of
this zone.
Caragana spp. desert steppe (site B). Dominated by this
woody semi-shrub, interspersed with various short grasses and forbs,
usually on a bright sandy soil. Rodents like to burrow under the
shrubs; its cooler here. The distribution of the shrubs varies
according to soil moisture availability and inter-shrub distances range
from 2m to 10m; see this photo.
Degraded S.krylovii typical steppe (site G). This site is in a transitional zone or ecotone between the desert and typical steppe zones which is still sometimes described as typical steppe. The dominant species should be Stipa krylovii but this is much sparser now in the southern part probably as a result of intense overgrazing; large parts of this zone have been occupied by Neopallasia pectinata, a short, yellow forb once thought to be a type of Artemisia. Efforts are being made to restore large areas within this zone by fencing to protect the grassland from grazing livestock. However, this does not appear to be very effective for reasons unknown; see this photo. The best estimates of the distribution of serious degraded grassland in the mid-1980s can be see on this AVHRR false colour composite.
Artemisia frigida typical steppe (site C). This training
area comprises Artemisia frigida grassland in its northern half (which
is thought to be degraded steppe) and A. frigida /
Allium mongolicum / Carex spp. grassland in its southern half, which is
bordered by a number of small, shallow lakes. Artemisia frigida is a
silvery forb which is thought to be one of the indicators of degradation under
regressive succession (Li Yonghong, 1990); it looks like this.
Stipa grandis typical steppe (site D). This site is on more
elevated ground about 60km north of the capital of Xilingol Aimag,
Xilinhot. A small part of the site in the east is reservation steppe and
is grazed only lightly. Stipa grandis can grow to almost 1 metre at
the peak of the growing season (late August) and A. chinense is
almost always present with it. This photo shows
middle-quality steppe of this kind, close to a brick settlement (the
traditional Mongolian yurt is becoming increasingly rare as the main
dwelling for herders as standards of living improve).
Lush A. chinense (syn. Leymus chinensis) typical
steppe (site E). This site is located about 70km south of Xilinhot city and
is a large haymaking reserve; only very light grazing by a few horses is
permitted. Elevation is relatively high; the area's name in Mongolian
"Huitenshile": means "cold mountain". There is a
greater diversity of plant types in this area and leaf area index is higher
than in any other location in the typical steppe zone : this is climax A. chinense steppe.
Lush S.grandis typical steppe. This site is on higher
elevation ground where S.grandis dominates over A. chinense.
This is climax S.grandis steppe with a high leaf area index.
A. chinense typical steppe (site F). This site is grazed typical steppe with a higher proportion of A. chinense than Stipa grandis. This species, known as "sheep grass" in Chinese (yang cao), appears slightly blue when soil moisture conditions are favourable; see the bluish patch in the middle distance in this photo. Note also the small flat-topped hill on the right; this is a common landform feature in this high plateau region where volcanic activity was once widespread.
Saline soils. This is a large salt pan and appears very
bright in both VIS and NIR channels. According to Chinese land cover and vegetation type maps compiled
from high resolution satellte imagery and field surveys, in the mid-1980s
there was a small saline lake just to the west of the training site, which
was itself described as covered with an Achnatherum splendens
community. This tall, rather splendid halophytic (salt-tolerant) plant
occurs were soil moisture is relatively abundant, such as close to rivers
and where the water table comes close hillsides. From the imagery
presented here and from the field survey, there is no indication of either
lake or vegetation. Only very, very sparse vegetation was seen in the
vicinity of the site. These changes may be an indication of increasing
aridity over the ~10-year period; the area experienced extraordinarily
high precipitation during the summer months and certainly for many days
prior to 13th August.
Sparse dwarf elm (Ulmus pumilla) and grasses. This site is located in a zone known as the "Hunshandake sandyland" and is also referred to as "sparse forest steppe". The landscape comprises small sandy hillocks interspersed with dwarf elm; it extends in a broad band adjoining the desert steppe zone in the west and the typical steppe zone in the east.
