What does alpine meadow mean?

Meadow is a vegetation type with perennial herbs as the main body, which developed under the condition of moderate moisture.

The difference between meadow and grassland is that grassland is dominated by xerophytes and is a zonal vegetation under semi-humid and semi-arid climate conditions; Generally, meadow belongs to non-zonal vegetation and can appear in different vegetation zones. Perennial herb communities are distributed in areas with humid climate and soil, no forests or forests. It can be divided into alpine meadow, lowland meadow and forest meadow.

Grazing and mowing. There are many kinds of grasslands. According to the topographic position of meadow distribution, there are usually two methods to divide meadow into flood plain meadow, continental meadow, lowland meadow, subalpine meadow and alpine meadow. The second is the plant community method, which divides the meadow into grass meadow, Carex meadow and grass meadow.

There is usually a dynamic balance between grassland and related vegetation types. Sometimes, drought, fire or intensive grazing are beneficial to grassland formation, while at other times, rainy season and no major interference are beneficial to woody vegetation growth. The change of frequency and severity of these factors will lead to the overall change of vegetation types.

Brief introduction of soil characteristics of alpine meadow

There is obvious accumulation of humus in alpine meadow soil, and the humus layer is 8 ~ 20 cm thick, showing a gray-brown to dark-brown granular-flat core structure. The content of organic matter is 10 ~ 20%, mainly fulvic acid, and the ratio of humic acid to fulvic acid (H/F) is 0.6 ~ 1.0. Soil composite colloid belongs to the type of high organic matter and low complexity, mainly loosely combined humus. The color of the humus layer fades rapidly downward.

In the subalpine zone, the transition between soil layers is rapid and obvious; But it is not obvious in the high mountain (true mountain) zone, and a dark layer appears in AB layer. Water-soluble salts and calcium carbonate in the profile have been leached out, and calcium carbonate has only accumulated in the middle and lower parts of some alpine meadow soil profiles.

Clay particles and trioxide have little change in profile, and clay minerals are mainly hydromica, with a small amount of kaolinite and vermiculite. It is acidic to neutral. The soil layer is only 40 ~ 50 cm thick, which has obvious micro-morphological characteristics of thawing and freezing, and the bottom layer has seasonal frozen soil layer or permafrost.