2.1 Study area
The study area is in the Niangniangshan National Wetland Park
Conservation area in China. The wetland is located at the junction of
Yunnan-Guizhou Province with geographical coordinates of 104°45 ’24
”E-104°51’ 41” E and 26°04 ’25 ”N-26°8’ 24” N. It is a typical
subtropical karst mountain moss peatlands wetland in the Yunnan-Guizhou
Plateau. Moss peatlands are developed in the waterlogged areas of basalt
formations on subalpine platforms and have important functions such as
water conservation, biodiversity protection, climate regulation and
carbon sink. Before the 1990s, a large area of moss peatlands was
distributed in the wetland, and different topographic environments
formed different moss peatlands, including ombrotrophic PB in the
plateau area and minerotrophic SF in the low-lying area. However, in the
late 1990s, large-scale drainage and construction of theCryptomeria fortuneana forest resulted in the disappearance of a
large area of moss peatlands. The vegetation was mainly swamp forest,
and the moss peatlands and herbaceous peatlands were mosaic landscapes.
The ecological function of wetlands declined significantly, and the
diversity and heterogeneity of vegetation and the environment decreased.
The climate of the area where the wetland is located is cool and humid,
which is a typical subtropical monsoon climate. The extreme maximum
temperature is 36.7 °C, the extreme minimum temperature is -7.9 °C, and
the annual average temperature is 15.2 °C. The average annual sunshine
duration is 1615 h, and the percentage of sunshine is 37%. The average
annual rainfall is 1413.6 mm, and the average evaporation is 1526.7 mm.
The annual average relative humidity is 76%, the maximum relative
humidity is 100%, and the minimum relative humidity is 2%. The annual
average frost-free period is 271 days. The main soil types in the
wetland conservation area are peat soil and scrub meadow soil.